his.sePublications
Change search
Refine search result
3456789 251 - 300 of 1603
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 251.
    Bjurén, Johan
    University of Skövde, School of Informatics.
    USING CASE-BASED REASONING FOR PREDICTING ENERGY USAGE2013Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    In this study, the inability to in a future meet the electricity demand and the urge to change the consumption behavior considered. In a smart grid context there are several possible ways to do this. Means include ways to increase the consumer’s awareness, add energy storages or build smarter homes which can control the appliances. To be able to implement these, indications on how the future consumption will be could be useful. Therefore we look further into how a framework for short-term consumption predictions can be created using electricity consumption data in relation to external factors. To do this a literature study is made to see what kind of methods that are relevant and which qualities is interesting to look at in order to choose a good prediction method. Case Based Reasoning seemed to be able to be suitable method. This method was examined further and built using relational databases. After this the method was tested and evaluated using datasets and evaluation methods CV, MBE and MAPE, which have previously been used in the domain of consumption prediction. The result was compared to the results of the winning methods in the ASHRAE competition. The CBR method was expected to perform better than what it did, and still not as good as the winning methods from the ASHRAE competition. The result showed that the CBR method can be used as a predictor and has potential to make good energy consumption predictions. and there is room for improvement in future studies.

  • 252.
    Björkenstam, Staffan
    et al.
    Geometry and Motion Planning group, Fraunhofer-Chalmers Center, Göteborg, Sweden.
    Nyström, Johan
    Geometry and Motion Planning group, Fraunhofer-Chalmers Center, Göteborg, Sweden.
    Carlson, Johan S.
    Geometry and Motion Planning group, Fraunhofer-Chalmers Center, Göteborg, Sweden.
    Roller, Michael
    Department of Mathematical Methods in Dynamics and Durability, Fraunhofer Institute for Industrial Mathematics, Kaiserslautern, Germany.
    Linn, Joachim
    Department of Mathematical Methods in Dynamics and Durability, Fraunhofer Institute for Industrial Mathematics, Kaiserslautern, Germany.
    Hanson, Lars
    Scania AB, Södertälje, Sweden.
    Högberg, Dan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Leyendecker, Sigrid
    Chair of Applied Dynamics, University of Erlangen-Nuremberg, Germany.
    A framework for motion planning of digital humans using discrete mechanics and optimal control2017In: Proceedings of the 5th International Digital Human Modeling Symposium / [ed] Sascha Wischniewski & Thomas Alexander, Federal Institute for Occupational Safety and Health , 2017, p. 64-71Conference paper (Refereed)
    Abstract [en]

    In this paper we present a framework for digital human modelling using discrete mechanics and optimal control. Discrete mechanics is particularly well suited for modelling the dynamics of constrained mechanical systems, which is almost always the case when considering complex human models interacting with the environment. We demonstrate that, by using recently developed recursive dynamics algorithms, we are able to efficiently use discrete mechanics in direct optimal control methods to plan for complex motions. Besides a proper mechanical model, an appropriate objective function is paramount to achieve realistic motions as a solution to an optimal control problem. Hence, several different objective functions, such as for example minimum time or minimum applied torque over the joints, are compared, and the resulting motions are analyzed and evaluated. To further improve the model, we include basic muscular models for the muscles of the shoulder, arm and wrist, and examine how this affects the motions.

  • 253.
    Björkqvist, Madeleine
    University of Skövde, School of Informatics.
    Voice interaction in intelligent vehicles: How can we design characteristics to create appropriate trust while entering an intelligent vehicle?2018Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Driving an autonomic vehicle is terrifying to a lot of people, especially for those without knowledge and experience of this type of technology. Today, several companies within the automotive industry are working towards autonomous driving. Tesla, Waymo and Uber are three companies who already has the technology to drive autonomously. It is the future and this technology changes the driver’s role. The driver is now not only expected to take control but also to give control to the system. As mentioned above, this change is not welcomed by everyone due to fear. This is a challenge for the automotive industry and the question is therefore how the industry can make people trust the vehicles of the feature?

    This thesis is focused on how one can design appropriate trust through voice interaction in autonomous cars, using the learning intelligent vehicle (LIV) which is a concept research platform by Veoneer. The research in this thesis includes a user study including an observation study that was conducted on a local fair in Vårgårda with focus on a UX perspective with possible future end users. Since there are restricted methods of evaluation methods on voice interaction, the author uses the Gricean Maxims to evaluate the existing voice interaction of LIV. By using user studies and the Gricean Maxims, the author argues that these methods can be used to identify trust characteristics and create appropriate trust before the actual launch of the vehicle/system. For example, when exhibit the autonomous vehicle to the public.

  • 254.
    Blomgren, Viktor
    University of Skövde, School of Informatics.
    Kriminella Stereotyper: En studie om populärkulturell visualisering av kriminella män i datorspel och hur betraktarens tokning påverkas av attribut och hudfärg2018Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The study sets out to examine what effect different attributes of a character have on how they are perceived as more or less criminal by swedish game development students, and if these attributes have a different effect depending on the characters skin color. Six characters were created for the study with designs inspired by Grand Theft Auto 5 (2013) and the study The Criminal Stereotype (Maclin, 2006). In two questionnaires, sent out to game development students att Högskolan i Skövde, the participants were asked to analyze three out of the six characters and describe them through preselcted possible answers, and to motivate their selected options. The results showed that there are attributes that are more closely related to criminal behaviour and that these exists as sterotypes in media on a global scale, as the results cohere to those from Maclins study. The results also show a difference in effect depending on the characters skin color as the informants were more cautious in their analysis of characters with a different ethnic background than themselves. Future research could focus on other graphical styles, other stereotypes or other ethnicities.

  • 255.
    Blomqvist, Viktor
    University of Skövde, School of Informatics.
    FÄRGS INVERKAN PÅ DOMINANTA SPELKARAKTÄRER: En studie kring karaktärskoncept för spel2015Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    De tekniska lösningarna inom spelgrafik har utvecklats till den grad att de numera kan förmedla sociala och känslomässiga budskap till spelaren genom relativt realistisk grafik och animation (Fiorito, 2000). Nästan alla spel görs i färg, vilket gör färg till en ständigt närvarande faktor i spelet och spelkaraktärers uttryck. Färg kan ge psykologiska associationer, till exempel att blått kan förstärka intrycket av lugn, att rött kan associeras till ilska och grönt med harmoni och natur (Panton, 1997). Detta gör att färg kan ses som ett verktyg som bland annat kan förmedla information om en spelkaraktär till spelaren. Genom att använda färgers associationsfaktorer inom generella färgkodningssystem kan en spelutvecklare ge spelaren ett intryck av en spelkaraktär innan spelaren hunnit interagera med den. Katherine Isbister (2006) skriver att genom användandet av stereotypiska rörelsemönster kan spelkaraktärens syfte eller attityd snabbt förmedlas till spelaren. Både färg och kroppsspråk kan uppfattas som nyckelkomponenter i gestaltandet av en spelkaraktär, då de båda kan ha inflytande på hur spelaren tolkar spelkaraktären och vad spelaren kommer att förvänta sig av den. Syftet med detta arbete är att studera färgs inverkan på graden av uppfattad makt och dominans från spelkaraktärer hos spelare. Hur dominans uttrycks kan variera kulturer emellan, precis som associationer till olika färger. Därför har arbetet begränsats till västerländsk kultur. NCS, Natural Color System är ett i Europa etablerat system som kategoriserar färg genom att jämföra dem med de kromatiska varianterna av gult, grönt, blått och rött, samt i vilken mängd akromatisk svart och vitt förekommer i blandningen. NCS ligger som grund för vilka färger som valdes att studera i undersökningen.

  • 256.
    Blomé, Mikael
    et al.
    Lunds Universitet.
    Dukic, Tania
    Chalmers.
    Hanson, Lars
    Lunds Universitet.
    Högberg, Dan
    University of Skövde, School of Engineering Science.
    Web-Based Protocol for Human Simulation Process and Documentation2003Conference paper (Other academic)
  • 257.
    Blomé, Mikael
    et al.
    Lund University.
    Hanson, Lars
    Lund University.
    Högberg, Dan
    University of Skövde, School of Technology and Society.
    Jönsson, Maria
    Arjo R&D Center.
    Lundström, Daniel
    CARAN AB .
    Lämkull, Dan
    Volvo Car Corporation.
    Visualisation of Human Characteristics in Vehicle and Health Care Product Development2007In: 2007 year’s SIGRAD conference: Uppsala University, 2007, November 29-30, Linköping University Electronic Press, 2007, p. 31-34Conference paper (Refereed)
    Abstract [en]

    The purpose of the research project described in this paper is to improve the efficiency of product development processes by exchanging knowledge and experiences about user centred design methods and technologies between the two branches: vehicle and health care industries. The health care industry can benefit from visualisation and simulation tools that include computer manikins, a physical representation of the human, and the vehicle industry can benefit from manikins having personal characteristics, which has proven to be successful in the health care industry.

  • 258.
    Blåder, Philip
    University of Skövde, School of Engineering Science. philipblader@hotmail.com.
    Bestående deformation av aluminiumhus vid presspassning2018Independent thesis Basic level (university diploma), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The deformation field of an aluminum housing that forms a press joint together with a ring wheel is analyzed in this study. The reason for the study is to get a better idea of the impact of interference fit on the aluminum housing using the Finita element method and practical measurement. Volvo Cars in Skövde asks for a method that can initially verify or dementiate deformations that may mean that the tolerances of the drawing are not obtained. The study will also provide an evaluation if the Finita element method is applicable to capture changes in the detail without confirmation of practical measurement.

    The analysis of the deformation field is performed with the Abaqus software, where the model's relevance is compared to practical measurement using a coordinate measuring machine and 3D scanner. The practical measurement is performed before and after pressing, the relevant holes and surfaces as shown. The FE model is created to mimic the dressing when the ring wheel is in place after pressing.

    The analysis shows that the material does not plasticize due to the radial displacement caused by the ring wheel. The FE simulation, on the other hand, shows that deformations occur on the relevant holes and surfaces examined during the practical measurement. Comparison between the results shows that the FE model provides a good picture of the deformation field and changes in the geometry that would mean that tolerances according to drawing would be difficult to obtain. Deviations between the results may be due to the simplifications made to the FE model but also to the measurement accuracy varied.

    FEM is considered to be applicable to create a better picture of the assembly process at an early stage before practical measurement was carried out. In order to avoid the drawing tolerances not being obtained, it is proposed that the aluminum housing be machined after pressing the ring wheel.

  • 259.
    Boberg, Arvid
    University of Skövde, School of Engineering Science.
    HRC implementation in laboratory environment: Development of a HRC demonstrator2018Independent thesis Advanced level (degree of Master (One Year)), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Eurofins is one of the world's largest laboratories which, among other things, offer chemical and microbiological analyses in agriculture, food and environment. Several 100.000 tests of various foods are executed each year at Eurofins’ facility in Jönköping and the current processes include much repeated manual tasks which could cause ergonomic problems. The company therefore wants to investigate the possibilities of utilizing Human-Robot Collaboration (HRC) at their facility. Human-Robot Collaboration is a growing concept that has made a big impression in both robot development and Industry 4.0. A HRC approach allow humans and robots to share their workspaces and work side by side, without being separated by a protective fence which is common among traditional industrial robots. Human-Robot Collaboration is therefore believed to be able to optimize the workflows and relieve human workers from unergonomic tasks.

    The overall aim of the research project presented is to help the company to gain a better understanding about the existing HRC technologies. To achieve this goal, the state-of-the-art of HRC had to be investigated and the needs, possibilities and limitations of HRC applications had to be identified at Eurofins’ facility. Once these have been addressed, a demonstrator could be built which could be used for evaluating the applicability and suitability of HRC at Eurofins.

    The research project presented used the design science research process. The state-of-the-art of HRC was studied in a comprehensive literature review, reviewing sterile robots and mobile robotics as well. The presented literature review could identify possible research gaps in both HRC in laboratory environments and mobile solutions for HRC applications. These areas studied in the literature review formed together the basis of the prepared observations and interviews, used to generate the necessary data to develop the design science research artefact, the demonstrator.

    ABB's software for robotic simulation and offline programming, RobotStudio, were used in the development of the demonstrator, with the collaborative robot YuMi chosen for the HRC implementation. The demonstrator presented in the research project has been built, tested and refined in accordance to the design science research process. When the demonstrator could illustrate an applicable solution, it was evaluated for its performance and quality using a mixed methods approach.

    Limitations were identified in both the performance and quality of the demonstrator's illustrated HRC implementation, including adaptability and sterility constraints. The research project presented could conclude that a HRC application would be possible at a station which were of interest by the company, but would however not be recommended due to the identified constraints. Instead, the company were recommended to look for stations which are more standardized and have less hygienic requirements. By the end of the research project, additional knowledge was contributed to the company, including how HRC can affect today's working methods at Eurofins and in laboratory environments in general.

  • 260.
    Boberg, Arvid
    University of Skövde, School of Engineering Science.
    Virtual lead-through robot programming: Programming virtual robot by demonstration2015Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This report describes the development of an application which allows a user to program a robot in a virtual environment by the use of hand motions and gestures. The application is inspired by the use of robot lead-through programming which is an easy and hands-on approach for programming robots, but instead of performing it online which creates loss in productivity the strength from offline programming where the user operates in a virtual environment is used as well. Thus, this is a method which saves on the economy and prevents contamination of the environment. To convey hand gesture information into the application which will be implemented for RobotStudio, a Kinect sensor is used for entering the data into the virtual environment. Similar work has been performed before where, by using hand movements, a physical robot’s movement can be manipulated, but for virtual robots not so much. The results could simplify the process of programming robots and supports the work towards Human-Robot Collaboration as it allows people to interact and communicate with robots, a major focus of this work. The application was developed in the programming language C# and has two different functions that interact with each other, one for the Kinect and its tracking and the other for installing the application in RobotStudio and implementing the calculated data into the robot. The Kinect’s functionality is utilized through three simple hand gestures to jog and create targets for the robot: open, closed and “lasso”. A prototype of this application was completed which through motions allowed the user to teach a virtual robot desired tasks by moving it to different positions and saving them by doing hand gestures. The prototype could be applied to both one-armed robots as well as to a two-armed robot such as ABB’s YuMi. The robot's orientation while running was too complicated to be developed and implemented in time and became the application's main bottleneck, but remained as one of several other suggestions for further work in this project.

  • 261.
    Bohlin, R.
    et al.
    Fraunhofer-Chalmers Research Centre for Industrial Mathematics, Gothenburg, Sweden.
    Delfs, N.
    Fraunhofer-Chalmers Research Centre for Industrial Mathematics, Gothenburg, Sweden.
    Hanson, Lars
    Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden.
    Högberg, Dan
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Carlson, J. S.
    Fraunhofer-Chalmers Research Centre for Industrial Mathematics, Gothenburg, Sweden.
    Automatic creation of virtual manikin motions maximizing comfort in manual assembly processes2012In: Technologies and Systems for Assembly Quality, Productivity and Customization: Proceedings of the 4th CIRP Conference on Assembly Technologies and Systems / [ed] S. Jack Hu, Conference on Assembly Technologies & Systems (CIRP), 2012, p. 209-212Conference paper (Refereed)
    Abstract [en]

    Effective simulation of manual assembly operations considering ergonomic load and clearance demands requires detailed modeling of human body kinematics and motions, as well as a tight coupling to powerful algorithms for collision-free path planning. The focus in this paper is a unified solution that automatically creates assembly motions for manikins taking kinematic constraints, balance, contact forces, collision avoidance and comfort into account. The manikin used in this work has 162 degrees of freedom - six exterior fictitious joints determine the position of the lower lumbar and the remaining ones are interior joints. The inverse kinematic problem leads to an underdetermined system allowing us to pick a solution that maximizes a scalar valued comfort function. The comfort function offers a generic way to give preference to certain poses while avoiding others, typically by considering joint limits, forces and moments on joints, and magnitude of contact forces. In order to avoid collisions, poses close to collision are penalized. The method is implemented and demonstrated on two challenging assembly operations taken from the automotive industry.

  • 262.
    Bohlin, Robert
    et al.
    Fraunhofer-Chalmers Research Centre for Industrial Mathematics.
    Delfs, Niclas
    Fraunhofer-Chalmers Research Centre for Industrial Mathematics.
    Hanson, Lars
    Chalmers University of Technology.
    Högberg, Dan
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre.
    Carlson, J. S.
    Fraunhofer-Chalmers Research Centre for Industrial Mathematics.
    Unified solution of manikin physics and positioning - Exterior root by introduction of extra parameters2011In: Proceedings of DHM, First International Symposium on Digital Human Modeling, Université Claude Bernard Lyon , 2011Conference paper (Refereed)
    Abstract [en]

    Simulating manual assembly operations considering ergonomic load and clearance demands requires detailed modeling of human body kinematics and motions, as well as a tight coupling to powerful algorithms for collision-free path planning. The focus in this paper is kinematics including balance and contact forces, and ergonomically preferable motions in free space. A typical manikin has more than 100 degrees of freedom. To describe operations and facilitate motion generation, the manikin is equipped with coordinate frames attached to end-effectors like hands and feet. The inverse kinematic problem is to find joint values such that the position and orientation of hands and feet matches certain target frames during an assembly motion. This inverse problem leads to an underdetermined system of equations since the number of joints exceeds the end-effectors' constraints. Due to this redundancy there exist a set of solutions, allowing us to consider ergonomics aspects and maximizing comfort when choosing one solution.The most common approach to handle both forward and inverse kinematics is building a hierarchy of joints and links where one root must be defined. A popular place to define the root is in a body part, e.g. in a foot. This leads to a two-step procedure; (i) one level determining when to re-root when moving the root part, (ii) then the Penrose pseudoinverse is used to match the end-effectors' constraints.In this paper we propose using a fixed exterior root by introducing six additional parameters positioning the lower lumbar - three rotations and three translations. This makes it possible to reposition the manikin without a series of re-rooting operations. Another important aspect is to keep the manikin, affected by internal and external forces and moments, in balance. However, by utilizing the exterior root and its added degrees of freedom it is possible to solve the balance, positioning, contact force and comfort problems simultaneously in a unified way. A manikin was implemented, and two test cases demonstrate the applicability of the presented method.

  • 263.
    Bolling, Maxine
    University of Skövde, School of Informatics.
    NPC:er och ansiktsbehåring: Spelares uppfattning av NPC-funktion i relation till ansiktsbehåring2017Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Detta är en studie vilken har undersökt spelares uppfattning av en NPC:s funktion i en fiktiv 1800-talskontext i relation till NPC:ens ansiktsbehåring. Människor har genom tiderna kategoriserat individer i form av stereotyper baserat på visuella aspekter, så som bland annat ansiktsbehåring. Stereotyper förväntas bete sig enligt specifika regler, och om en karaktär inte beter sig som dess publik förväntar sig uppstår dissonans (Loyall, 1997). Undersökningens artefakt bestod av en serie porträtt föreställandes en och samma NPC men med varierande uppsättningar ansiktsbehåring. Studiens respondenter ombads tilldela vart porträtt en NPC-funktion baserade på Bartles (2004) lista med NPC-funktioner. Resultatet visade på trender där ett fåtal funktioner föredrogs för var form av ansiktsbehåring. I framtida arbeten skulle andra kontexter kunna undersökas. Även mer avancerade undersökningar skulle kunna genomföras där NPC:erna placeras i en spelsimulation.

  • 264.
    Borén, Sven
    University of Skövde, School of Technology and Society.
    Analys av ventilmekanism i Husabergs motorcykelmotor2009Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The small company Husaberg design and develop motorcycles for competition purpose with the goal to be the best of the best and not be too expensive. The field testing is often used to determine the design, which in some cases will then miss a few essential safety factors. The powerful four-stroke engine is design to ensure high rideability and is based on the old Husqvarna motorcycle engines. To re-calculate and test everything when doing changes would be very expensive and time consuming and the field testing is therefore the most common verification method, even if the fatigue properties can’t be established.The engine has no overspeed protection and that, combined with reaching beyond the yield strength limit (Relmin) in the rocker fingers that pushes down the exhaust poppet valves, does result in fatigue.Husaberg enlarged in 1996 the rocker fingers where they broke off and the consumer claims ceased.

  • 265.
    Bremert, Michael
    et al.
    University of Skövde, School of Technology and Society.
    Persson, Stefan
    University of Skövde, School of Technology and Society.
    Flermålsoptimering och analys av produktionslinje samt identifiering av förbättringsmål2012Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    To meet the demands from their customers Volvo Powertrain has set a new production goal for cylinder heads for 13-liter diesels engines. The production lines are built as a flow line of grouped CNC machines, served by a gantry for loading and unloading. The new production goal for one of the production lines, segment 2, is 33 cylinder heads per hour. Volvo Powertrain has also found through the production monitoring-system, Duga, that the waiting time for the loading equipment is a significant amount of the available production time.

    The aim of this project is hence twofold: (1) to verify that the calculations of the waiting time made in Duga are correct; (2) to investigate and propose improvements for the production line in order to achieve the original targeted production goal. This has been done by using simulation and simulation-based optimization technology and for this purpose a generic simulation module of a gantry was made. This project will not answer questions regarding economic consequences, staffing and quality losses in the production line.

    A simulation model has been built in the first phase of the project for a machining cell in Segment 2, which contains one gantry for the loading and unloading operations of four different CNC machining centers connected in series. The simulation model shows that the waiting time of the loading equipment in real time is not as big as what is calculated in Duga. This discrepancy is due to a misleading definition of the waiting time made in Duga.

    The generic gantry module has been used to build a simulation model of Segment 2. Three different optimization runs has been made with an optimization client from the University of Skövde. One of the optimization runs found a solution that matches Volvo Powertrains production goal. From this optimization run one preferred and realistic solution was chosen. The solution includes new levels in buffers along the production line, line balancing and improved availability to the different machines and gantries. The preferred and realistic solution increases the production rate by 10%.

     

  • 266.
    Brolin, Anna
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Engineering Science.
    An investigation of cognitive aspects affecting human performance in manual assembly2016Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Modern manufacturing systems seem to be shifting from mass production to mass customisation, which means that systems must be able to manage changes in customer demands and requirements, new technology as well as environmental demands. This in turn leads to an increase in product variants that need to be assembled. To handle this issue, well designed and presented information is vital for assembly workers to perform effective and accurate assembly tasks. In this thesis the main focus has been to find factors that affect human performance in manual assembly. A literature review was made on the subject of manufacturing and usability as well as basic cognitive abilities used to utilise information, such as memory. This investigation identified applicable factors for assessing human cognitive performance within the research field of manufacturing. The thesis further investigates how some of these factors are handled in manual assembly, using case studies as well as observational studies. The results show that how material and information are presented to the assembler needs to be considered in order to have a positive effect on the assembly operation. In addition, a full factorial experimental study was conducted to investigate different ways of presenting material and information at the workstation while using mixed assembly mode with product variants. The material presentation factor involved the use of a material rack compared to using an unstructured kit as well as a structured kit and the information presentation factor involved using a text and number instruction compared to a photograph instruction. The results showed that using a kit is favourable compared to the traditional material rack, especially when using a structured kit combined with photographic instruction. Furthermore, the use of unstructured kits can lead to better productivity and reduced perceived workload, compared to a material rack. Although they are perhaps not as good as using a structured kit, they most likely bring a lower cost, such as man-hour consumption and space requirements. However, the number of components in an unstructured kit needs to be considered in order to keep it on a manageable level. As a conclusion, several scenarios were developed in order to understand how different assembly settings can be used in order to improve human performance at the assembly workstation.

  • 267.
    Brolin, Anna
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Brolin, Erik
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Högberg, Dan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Second cycle education program in virtual ergonomics and design2018In: Proceedings of the 20th Congress of the International Ergonomics Association (IEA 2018): Volume VII: Ergonomics in Design / [ed] Sebastiano Bagnara, Riccardo Tartaglia, Sara Albolino, Thomas Alexander, Yushi Fujita, Cham: Springer, 2018, Vol. 824, p. 1058-1065Conference paper (Refereed)
    Abstract [en]

    Current product and production development tends to become more complex where principal design decisions are made in very early development phases when product data only exist in virtual formats. To support this virtual product realisation process there exist a number of tools and technologies. Considering ergonomics and human factors in an increasingly complex process with often complex tools requires competent people able to handle multidisciplinary development challenges in a proactive manner. To answer the need for educational programs to cover these issues the School of Engineering Science at University of Skövde has developed a new master (second cycle) program Virtual Ergonomics and Design. The aim with the program is to give students and future product and production developers, necessary knowledge and skills to effectively use virtual tools for analysis, development, and verification of ergonomics and integrate ergonomics and user aspects into the product realisation process. This is achieved through a number of courses that partly forms a core within the subject Virtual product realisation but also provides in-depth knowledge in ergonomics. Students will in a possible future role as design or production engineers have a great influence on ergonomics in manufacturing departments but also better perception of ergonomics, higher motivation and knowledge of support tools and methods for ergonomics integration.

  • 268.
    Brolin, Anna
    et al.
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre.
    Bäckstrand, Gunnar
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre.
    Högberg, Dan
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre.
    Case, Keith
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre.
    Use of kitting to ease assemblers' cognitive workload2011In: Proceedings of the 43rd Annual Nordic Ergonomics Society Conference, University of Oulu , 2011, p. 77-82Conference paper (Refereed)
    Abstract [en]

    The higher level of product variation in the automotive industry leads to an increasing workload for the assembler that has to search, fetch and assemble all the variants. This puts high demands on the information that is given to the assembler to fulfil the assembly task. This paper describes the impact of information overload and sources, and their influence on the assembler. Through observations conducted in the Swedish automotive industry, the study has shown that the assembly personnel perceive the kit as structured information and that structured kits are able to present distinct information at a certain place to the assembler, which in turn reduces the searching, resulting in decreased cognitive workload.

  • 269.
    Brolin, Anna
    et al.
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Bäckstrand, Gunnar
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Thorvald, Peter
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Högberg, Dan
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Case, Keith
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Kitting as an information source in manual assembly2012In: Advances in Ergonomics in Manufacturing / [ed] Stefan Trzcieliński & Waldemar Karwowski, CRC Press, 2012, p. 346-353Chapter in book (Refereed)
    Abstract [en]

    In manual assembly, a strategy to meet the goal of efficient production is the increased use of kitting as a material supply principle. Even though kitting is already implemented in industry, there are still uncertainties regarding the effects of introducing kits, particularly from a human factors perspective.

    This paper presents initial steps in the development of a method to be used for the evaluation of kitting. This from an information source point of view and for studying effects related to productivity and quality. The methodology is projected to act as a foundation for how to carry out a subsequent comprehensive case study. The purpose of the case study is to explore how kitting affects the cognitive workload compared to the ordinary material rack combined with part numbers used in the current manufacturing industry. This is done by measuring productivity; time spent on assembling a product, and quality; number of assembly errors. One step in the methodology development process, which is described in this paper, was to conduct a pilot study, primarily to test the methodology related to the selection of measurement parameters, as well as for getting experiences from running the methodology with real test subjects.

  • 270.
    Brolin, Anna
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, UK.
    Case, Keith
    Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, UK.
    Thorvald, Peter
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Cognitive Aspects Affecting Human Performance in Manual Assembly2016In: Advances in Manufacturing Technology XXX / [ed] Yee Mey Goh, Keith Case, IOS Press, 2016, p. 231-236Conference paper (Refereed)
    Abstract [en]

    This paper concerns the handling of information in assembly work environments. Several studies involving both literature reviews, case studies andobservations were conducted to find factors that affect human performance in manual assembly. The main experiment with 36 subjects used a mixed method design with a quantitative study, including time and errors as dependant measures,a qualitative study, including workload ratings, and a questionnaire. The experiment involved the assembly of a pedal car and the components werepresented using structured kits, unstructured kits and material racks. Assembly information was presented as text & component numbers or photographs, and situations with and without component variation were considered. Among theresults it was found that assembly times and workload ratings were lower when using a kit, whereas using a material rack resulted in perceived decreased workflow and increased stress and frustration. Assembly times and workload ratings were lower when using photographs, whereas using text and numbers increased mental workload.

  • 271.
    Brolin, Anna
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Case, Keith
    Loughborough University, United Kingdom.
    Thorvald, Peter
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Interaction Effects Affecting Human Performance in Manual Assembly2018In: Advances in Manufacturing Technology XXXII: Proceedings of the 16th International Conference on Manufacturing Research, incorporating the 33rd National Conference on Manufacturing Research, September 11–13, 2018, University of Skövde, Sweden / [ed] Peter Thorvald, Keith Case, Amsterdam, Netherlands: IOS Press, 2018, p. 265-270Conference paper (Refereed)
    Abstract [en]

    This paper presents an experimental study aimed at investigating interaction effects affecting personnel in manual assembly. The main experiment with 36 subjects used a mixed method design which included a quantitative study, including time and errors as dependent measures, and a qualitative study, including workload ratings and a questionnaire. The overall task in the experiment was to assemble components on a pedal car. The main factors involved were assembly information (text & component numbers or photographs), material presentation (using structured kits, unstructured kits and material racks) and component variation (situations with and without component variation). It was found that performance, measured in assembly time, was best when combining photographs with no component variants and when using an unstructured kit.

  • 272.
    Brolin, Anna
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Department of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough, United Kingdom.
    Thorvald, Peter
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Case, Keith
    Department of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough, United Kingdom.
    Experimental study of cognitive aspects affecting human performance in manual assembly2017In: Production & Manufacturing Research, ISSN 2169-3277, Vol. 5, no 1, p. 141-163Article in journal (Refereed)
    Abstract [en]

    This study investigate different ways of presenting material and information at workstations while using mixed assembly mode with product variants. The experimental set up annotated an assembly line involving 36 subjects. The material presentation factor involved the use of a material rack compared to using an unstructured kit as well as a structured kit. The information presentation factor involved using a text and number instruction compared to a photograph instruction, and situations with and without component variation were considered. Results show that assembly times and workload ratings were lower when using a kit, whereas using a material rack resulted in perceived decreased workflow and increased stress and frustration. Moreover, assembly times and workload ratings were lower when using photographs, whereas using text and numbers increased mental workload. The results could be useful when planning work places and production systems in order to obtain a better workflow and an increased human performance. 

  • 273.
    Brolin, Erik
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Chalmers University of Technology.
    Anthropometric diversity and consideration of human capabilities: Methods for virtual product and production development2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Contemporary product and production development is typically carried out with the support of computer tools where the design of products and workstations are originated and evaluated within virtual environments. Ergonomics addresses factors important to consider in the product and production development process to ensure a good fit between humans and the items being designed. Digital human modelling (DHM) tools enable simulations and analyses of ergonomics in virtual environments. Anthropometry is central when using DHM tools for product and production development to ensure that the design fits the intended proportion of the targeted population from a physical perspective. Several methods have been prescribed to consider the anthropometric diversity that exists within human populations. Still many DHM based simulations in product and production development processes are done with approaches that are poor in representing anthropometric diversity. Hence, there is a need for better tools and methods that would support DHM tool users to more effectively and efficiently consider anthropometric diversity in the design process.

    In this thesis current methods for anthropometric diversity considerations have been reviewed and new methods and functionality have been developed and implemented in a DHM tool. Mathematical models have been developed to consider three specific parts important to the consideration of anthropometric diversity: generation of suitable test cases, prediction of missing anthropometric data and implementation of more diverse anthropometric variables such as strength and flexibility. Results show that the proposed methods are accurate and advantageous compared to approaches often used in industry today. The mathematical models for generation of suitable test cases and prediction of missing anthropometric data have been implemented in an anthropometric software module. The module has undergone usability testing with industry DHM tools users. The developed anthropometric module is shown to answer to relevant needs of DHM tool users and fit into the work processes related to DHM simulations and ergonomics analyses utilised in industry today.

  • 274.
    Brolin, Erik
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre.
    Consideration of anthropometric diversity: Methods for virtual product and production development2012Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Ergonomics and Human Factors address factors important to consider in the product and production development process. This is done through a User Centred Design process where focus is put on human-machine interactions. Digital human modelling (DHM) tools provide and facilitate rapid simulations, visualisations and analyses of the human-machine interactions in a virtual environment. Anthropometry, the study of human measurements, is central in DHM simulations due to the necessity of ensuring intended accommodation levels. Several methods have been described to consider the anthropometric diversity that exists within human populations. Still, many simulations are done with few human models, so called manikins, in industry today due to the time consuming processes when working with many manikins in current DHM tools. Hence, there is a need for better tools and methods. To increase the understanding among DHM users there is also a need to illustrate differences in results when using different approaches, and to evaluate the validity of the assumptions that methods for anthropometric diversity consideration are based upon.

    In this thesis current methods for anthropometric diversity considerations have been reviewed and the differences in evaluation results when utilizing different approaches have been analysed. New methods and functionality have been developed and implemented in DHM tools and the possibilities to include more physical characteristics and in turn consider more aspects of human diversity have been explored. Results shows that the proposed methods are advantageous compared to approaches often used in industry today and will, if used, increase the consideration of anthropometric diversity when using DHM tools for the design of products and workplaces.

  • 275.
    Brolin, Erik
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden.
    Hanson, Lars
    Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden / Industrial Development, Scania CV, Södertälje, Sweden.
    Högberg, Dan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Digital human arm models with variation in size, strength and range of motion2014In: / [ed] Masaaki Mochimaru and Makiko Kouchi, 2014Conference paper (Refereed)
    Abstract [en]

    Digital human modelling (DHM) systems can be used to simulate production processes and analyse the human-machine interaction, particularly at early design stages. The human-machine interaction is affected and limited by factors or characteristics belonging to the human user and the machine or product but also the surrounding environment. DHM systems consider in most cases only physical user capabilities and with focus on consideration of body size related anthropometric diversity. However, the human-machine interaction is not only affected by the size and proportions of a user but for example also the user´s muscle strength and range of motion (ROM). This paper describes a study where diversity in strength and ROM, together with diversity in body size, is implemented in the process of creating data for a group of human arm models. A literature study was done to investigate the diversity of strength and ROM and the correlation between such measurements and body size data. The results from the literature study showed that there is little correlation between body size, strength and ROM. The study also showed that there are few published studies where body size, strength and ROM have been tested at the same time. From the literature study, generic correlation coefficients between body size, strength and ROM were synthesized. Using these correlation coefficients and Principal Component Analysis, data for a group of 14 female arm models with varying body size, strength and ROM were calculated. The results show that it is possible to introduce additional variables such as strength and ROM, but also that data of the correlation between body size and other types of anthropometric measurements are scarce. New measurement studies are important to decrease the uncertainties when predicting correlation coefficients between body size, strength and ROM variables.

  • 276.
    Brolin, Erik
    et al.
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society. Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden.
    Hanson, Lars
    Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden / Industrial Development, Scania CV, Södertälje, Sweden.
    Högberg, Dan
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Örtengren, Roland
    Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden.
    Conditional Regression Model for Prediction of Anthropometric Variables2013In: 2013 Digital human modeling symposium / [ed] Matt Reed, 2013Conference paper (Refereed)
    Abstract [en]

    In digital human modelling (DHM) systems consideration of anthropometry is central. Important functionality in DHM tools is the regression model, i.e. the possibility to predict a complete set of measurements based on a number of defined independent anthropometric variables. The accuracy of a regression model is measured by how well the model predicts dependent variables based on independent variables, i.e. known key anthropometric measurements. In literature, existing regression models often use stature and/or body weight as independent variables in so-called flat regressions models which can produce estimations with large errors when there are low correlations between the independent and dependent variables. This paper suggests a conditional regression model that utilise all known measurements as independent variables when predicting each unknown dependent variable. The conditional regression model is compared to a flat regression model, using stature and weight as independent variables, and a hierarchical regression model that uses geometric and statistical relationships between body measurements to create specific linear regression equations in a hierarchical structure. The accuracy of the models is assessed by evaluating the coefficient of determination, R2 and the root-mean-square deviation (RMSD). The results from the study show that using a conditional regression model that makes use of all known variables to predict the values of unknown measurements is advantageous compared to the flat and hierarchical regression models. Both the conditional linear regression model and the hierarchical regression model have the advantage that when more measurements are included the models will give a better prediction of the unknown measurements compared to the flat regression model based on stature and weight. A conditional linear regression model has the additional advantage that any measurement can be used as independent variable. This gives the possibility to only include measurements that have a direct connection to the design dimensions being sought. Utilising the conditional regression model would create digital manikins with enhanced accuracy that would produce more realistic and accurate simulations and evaluations when using DHM tools for the design of products and workplaces.

  • 277.
    Brolin, Erik
    et al.
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Högberg, Dan
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Hanson, Lars
    Industrial Development, Scania CV, Södertalje, Sweden / Chalmers University of Technology, Gothenburg, Sweden.
    Description of boundary case methodology for anthropometric diversity consideration2012In: International Journal of Human Factors Modelling and Simulation, ISSN 1742-5549, Vol. 3, no 2, p. 204-223Article in journal (Refereed)
    Abstract [en]

    This paper describes and evaluates the boundary case methodology for the simultaneous consideration of variance for a number of selected anthropometric variables. The methodology includes the calculation of key dimension values for extreme but likely anthropometric measurement combinations. This data can be applied when utilising digital human modelling (DHM) tools for proactive design work and entered as input data when representative manikins are defined. The mathematical procedure is clearly described and exemplified to demonstrate how to use the methodology in design work. The outcome of the method is illustrated and compared using several different cases where the number of measurements is varied and where principal component analysis (PCA) is used to reduce the number of dimensions in one case. The paper demonstrates that the proposed boundary case method is advantageous compared to approaches based on the use of univariate percentile data in design.

  • 278.
    Brolin, Erik
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden.
    Högberg, Dan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Hanson, Lars
    Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden / Industrial Development, Scania CV, Södertälje, Sweden.
    Design of a Digital Human Modelling Module for Consideration of Anthropometric Diversity2014In: Advances in Applied Digital Human Modeling / [ed] Vincent Duffy, AHFE Conference , 2014, p. 114-120Conference paper (Refereed)
  • 279.
    Brolin, Erik
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Högberg, Dan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Hanson, Lars
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden / Industrial Development, Scania CV, Södertälje, Sweden.
    Björkenstam, Staffan
    Fraunhofer-Chalmers Centre, Gothenburg, Sweden.
    Virtual test persons based on diverse anthropometric data for ergonomics simulations and analysis2017In: Proceedings of the 49th NES 2017 Conference "Joy at Work", Lund, August 20-23, 2017 / [ed] Anna-Lisa Osvalder, Mikael Blomé and Hajnalka Bodnar, Lund: Lund University, Faculty of Engineering , 2017, p. 232-239Conference paper (Refereed)
    Abstract [en]

    This paper describes a study where diverse anthropometric data is included in the process of generating data for a group of virtual test persons. Data on body size, strength and ROM were either collected on an individual level or predicted and synthesized and then used in cluster analyses to generate six unique virtual test persons. Results show that the method is able to generate detailed virtual test persons which enables more realistic and accurate simulations, as strength and ROM data is included into the motion prediction algorithms used to generate motions.

  • 280.
    Brolin, Erik
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden.
    Högberg, Dan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Hanson, Lars
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Industrial Development, Scania, Scania CV, Södertälje, Sweden / Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden.
    Örtengren, Roland
    Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden.
    Adaptive regression model for prediction of anthropometric data2017In: International Journal of Human Factors Modelling and Simulation, ISSN 1742-5549, Vol. 5, no 4, p. 285-305Article in journal (Refereed)
    Abstract [en]

    This paper presents and evaluates an adaptive linear regression model for the prediction of unknown anthropometric data based on a flexible set of known predictive data. The method is based on conditional regression and includes use of principal component analysis to reduce effects of multicollinearity between the predictive variables. Results from the study show that the proposed adaptive regression model produces more accurate predictions compared to a flat regression model based on stature and weight, and also compared to a hierarchical regression model, that uses geometric and statistical relationships between body measurements to create specific linear regression equations in a hierarchical structure. An additional evaluation shows that the accuracy of the adaptive regression model increases logarithmically with the sample size. Apart from the sample size, the accuracy of the regression model is affected by the number of, and on which measurements that are, variables in the predictive dataset.

  • 281.
    Brolin, Erik
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Chalmers University of Technology, Gothenburg, Sweden.
    Högberg, Dan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Hanson, Lars
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Chalmers University of Technology, Gothenburg, Sweden / Industrial Development, Scania CV, Södertälje, Sweden.
    Örtengren, Roland
    Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden.
    Adaptive regression model for synthesizing anthropometric population data2017In: International Journal of Industrial Ergonomics, ISSN 0169-8141, E-ISSN 1872-8219, Vol. 59, p. 46-53Article in journal (Refereed)
    Abstract [en]

    This paper presents the development of an adaptive linear regression model for synthesizing of missing anthropometric population data based on a flexible set of known predictive data. The method is based on a conditional regression model and includes use of principal component analysis, to reduce effects of multicollinearity between selected predictive measurements, and incorporation of a stochastic component, using the partial correlation coefficients between predicted measurements. In addition, skewness of the distributions of the dependent variables is considered when incorporating the stochastic components. Results from the study show that the proposed regression models for synthesizing population data give valid results with small errors of the compared percentile values. However, higher accuracy was not achieved when the number of measurements used as independent variables was increased compared to using only stature and weight as independent variables. This indicates problems with multicollinearity that principal component regression were not able to overcome. Descriptive statistics such as mean and standard deviation values together with correlation coefficients is sufficient to perform the conditional regression procedure. However, to incorporate a stochastic component when using principal component regression requires raw data on an individual level.

    Relevance to industry

    When developing products, workplaces or systems, it is of great importance to consider the anthropometric diversity of the intended users. The proposed regression model offers a procedure that gives valid results, maintains the correlation between the measurements that are predicted and is adaptable regarding which, and number of, predictive measurements that are selected.

  • 282.
    Brolin, Erik
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Högberg, Dan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Hanson, Lars
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Industrial Development, Scania CV, Södertälje.
    Örtengren, Roland
    Chalmers University of Technology, Gothenburg.
    Development and evaluation of an anthropometric module for digital human modelling systems2019In: International Journal of Human Factors Modelling and Simulation, ISSN 1742-5549, Vol. 7, no 1, p. 47-70Article in journal (Refereed)
    Abstract [en]

    This paper presents the development of a software module and a graphical user interface which aims to support the definition of anthropometry of manikins in a digital human modelling (DHM) tool. The module is developed from user interviews and literature studies, as well as mathematical methods for anthropometric diversity consideration. The module has functionality to create both single manikins and manikin families, where it is possible to combine or analyse different population datasets simultaneously. The developed module and its interface have been evaluated via focus group interviews and usability tests by DHM tool users. Results from the studies show that the developed module and its interface has relevant functionality, fits well into industrial work processes, and is easy to use. The study also identifies possibilities to further increase usability.

  • 283.
    Brolin, Erik
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden.
    Högberg, Dan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Hanson, Lars
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Industrial Development, Scania, Scania CV, Södertälje, Sweden / Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden.
    Örtengren, Roland
    Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden.
    Generation and evaluation of distributed cases by clustering of diverse anthropometric data2016In: International Journal of Human Factors Modelling and Simulation, ISSN 1742-5557, Vol. 5, no 3, p. 210-229Article in journal (Refereed)
    Abstract [en]

    This paper describes a study where diversity in body size, strength and joint range of motion, together with diversity in other capability measurements, is included in the process of generating data for a group of test cases using cluster analysis. Descriptive statistics and correlation data was acquired for 15 variables for different age groups and both sexes. Based on this data, a population of 10,000 individuals was synthesised using correlated random numbers. The synthesised data was used in cluster analyses where three different clustering algorithms were applied and evaluated; hierarchical clustering, k-means clustering and Gaussian mixture distribution clustering. Results from the study show that the three clustering algorithms produce groups of test cases with different characteristics, where the hierarchical and k-means algorithm give the most diverse results and where the Gaussian mixture distribution gives results that are in between the first two.

  • 284.
    Brolin, Erik
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Mahdavian, Nafise
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Högberg, Dan
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Hanson, Lars
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre. Industrial Development, Scania CV, Södertälje.
    Johansson, Joakim
    Bombardier Transportation Sweden AB, Västerås.
    Possibilities and challenges for proactive manufacturing ergonomics2019In: Proceedings of the 20th Congress of the International Ergonomics Association (IEA 2018): Volume VIII: Ergonomics and Human Factors in Manufacturing, Agriculture, Building and Construction, Sustainable Development and Mining / [ed] Sebastiano Bagnara, Riccardo Tartaglia, Sara Albolino, Thomas Alexander, Yushi Fujita, Cham: Springer, 2019, Vol. 825, p. 11-20Conference paper (Refereed)
    Abstract [en]

    This paper identifies and describes product development activities where ergonomics issues could be considered and illustrates how that could be done through a number of different approaches. The study is divided into two parts where an interview study is done to identify where in a product development process consideration of ergonomics issues are or could be done. The second part of the study includes an observation, motion capture and simulation study of current manufacturing operations to evaluate and compare three different assessment approaches; observational based ergonomics evaluation, usages of motion capture data and DHM simulation and evaluation. The results shows the importance of consideration of ergonomics in early development phases and that the ergonomics assessment process is integrated in the overall product and production development process.

  • 285.
    Brown, Ashley M. L.
    et al.
    Brunel University London, United Kingdom.
    Berg Marklund, Björn
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Animal Crossing: New Leaf and the Diversity of Horror in Video Games2015In: Proceedings of the 2015 DiGRA International Conference: Diversity of Play: Games – Cultures - Identities, Digital Games Research Association (DiGRA) , 2015Conference paper (Refereed)
    Abstract [en]

    This paper explores the diverse ways horror can be conveyed in games by investigating how games that are not associated with the horror genre can produce unsettling or scary experiences. To conduct this exploration, this study uses interaction mapping, as outlined by Consalvo and Dutton (2006), to examine a game that has thoroughly pleasant and cutesy trappings: Animal Crossing: New Leaf (Nintendo 2013). The interactions were analysed according to three themes prevalent within literature on horror and horror games: the loss of agency, the Freudian uncanny, and the Heideggerian uncanny. Ultimately, this paper demonstrates that a game which is not explicitly scary is occasionally made so through its rudimentary simulation of human behaviour and societal constructs as well as its autonomous functions and inclusion of real-world time, showing that games have very diverse means of conveying unsettling or horrifying experiences. The paper also shows how frameworks used to analyse games in the horror genre can be applicable to critical readings of non-horror games in order to understand the unexpected player reactions they can evoke.

  • 286.
    Brown González, Lorena
    et al.
    University of Skövde, School of Engineering Science.
    Palacios Certucha, Rodrigo
    University of Skövde, School of Engineering Science.
    The design of a playground toy2019Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The report describes the design of a safe (within EU regulations), ergonomic, attractive, sustainable, versatile and interactive playground toy for children from ages 7 to 11. The product aims to help children develop in different aspects: physical, emotional, social and mental, in a sustainable environment. This was developed from the identification and exploration of the factors that influence the design of playground toys. The design process was divided in the following main stages: an initial research of information, the interpretation of this data, the development of a concept, a test stage and the results. During the research, teachers and parents were interviewed and children were observed. Relevant information was also gathered. For the development, a set of creative techniques were applied and finally tested. Modifications based on the test were made to reach an accurate design. The work done was successful to the extent established initially; although, it can be subject to improvement. The main limit was that no tests were performed on a physical prototype, therefore, there is information not yet gathered and tests that would prove if some of the assumptions were true or false.  

  • 287.
    Bruzell, Therése
    University of Skövde, School of Informatics.
    Titta bort!: En undersökning om blickens betydelse hos kvinnliga karaktärer i spel.2019Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    I detta arbete undersöktes betydelsen av en kvinnlig karaktärs blick när det kommer till hur en betraktare använder sexualiserade och objektifierande stereotyper för att identifiera henne. En föregående studie av Fox och Bailenson (2009) användes som den primära referensen till arbetsområdet och hur artefakterna till undersökningen skulle designas. Madonna/Hora-komplexet (Bareket, Kahalon, Shnabel & Glick, 2018) användes som en av de objektifierande stereotyperna som undersökningen baserades på.

    Ur detta syfte formades frågeställningen: 

    • Hur uppfattar en betraktare en kvinnlig figurs personlighet om blicken bryter mot dess stereotyp?

    För att besvara frågeställningen skapades två olika artefakter föreställande en sexualiserad kvinna och en icke-sexualiserad i 3D. För att undersöka blicken gavs de två figurerna två olika blickar var, en direkt och en undvikande.

    Själva undersökningsmetoden bestod av gruppintervjuer uppdelade i fyra undersökningar. De första två grupperna fick se de två artefakterna med samma blick medan de två andra grupperna fick se de två artefakterna med olika blickar. Under undersökningens gång fick deltagarna diskutera artefakterna fritt tills de inte kunde komma på något mer att säga.

    Resultatet av undersökningen visade att blicken i helhet inte har en stor betydelse men att en stark blick jämförd med en undergiven blick får en sexualiserad karaktär med den starka blicken att bryta stereotypen och uppfattas som stark och utmanande. I övrigt hade blicken ingen betydelse mer än att den fick karaktärens känslouttryck att förändras. En icke-sexualiserad figur ansågs inte mindre självständig eller mer objektifierad om hennes blick var undergiven.

  • 288.
    Buller, Louise
    University of Skövde, School of Informatics.
    Errorless Learning: Som inlärningsmetod i dataspel2018Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Arbetets syfte är att svara på frågeställningen om errorless learning fungerar som inlärningsmetod i dataspel och hur väl den lär ut ett pussel/plattformsspel i 3Ds mekaniker till en spelare. En artefakt bestående av två prototyper som använde antingen errorless learning (EL) eller trial-and-error (TE) som inlärningsmetod skapades som hjälpmedel i arbetets undersökning.

    Undersökningens deltagare var fyra kvinnor och fyra män. Två kvinnor och två män spelade vardera prototyp. Undersökningen bestod av två spelsessioner och två intervjuer. Under spelsessionerna dokumenterades informanternas antal fel och speltid. Under intervjuerna dokumenterades informanternas inställning och uppfattning av spelsessionerna.

    Spelsessionerna visade inte några större skillnader förutom att en informant som spelade TE prototypen behövde hjälp med att använda en huvudmekanik. Under intervjuerna framgick det att majoriteten ansåg att vissa instruktioner behövs ifall mekaniken inte är en ”standardkontroll”. En informant ansåg att det inte behövdes några instruktioner. Slutsatsen är att EL fungerar som en inlärningsmetod i dataspel.

  • 289.
    Bystedt, Pontus
    University of Skövde, School of Humanities and Informatics.
    BILLBOARDS I SPEL: En illusion av 3d-karaktärer2014Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Billboarding är en teknik som ofta används i tv- eller dataspel för att prestandaeffektivt skapa objekt i en spelmiljö. Tekniken går ut på att istället för en 3d-modell ritas en bild med genomskinlig bakgrund ut på ett polygonplan som alltid vrids mot spelaren. Hur skulle detta kunna utvecklas? Problemformuleringen för denna studie lyder: Hur uppfattar betraktaren karaktärer som representeras av billboards ur flera vinklar istället för en 3d-modell?En spelmiljö med både 3d-karaktärer och billboardskaraktärer skapades. Billboardskaraktärerna bestod av bilder av 3d-karaktärerna för att ge illusionen av att de också var 3d-karaktärer. Kvalitativa intervjuer genomfördes för att ta reda på olika respondenters uppfattning om dessa billboardskaraktärer. Resultatet blev positivt. Även om ett fåtal kunde skilja på 3d-karaktärerna och billboardskaraktärerna kunde ingen genomskåda att billboardskaraktärerna inte var 3d-karaktärer. Resultatet skulle kunna utvecklas ytterligare genom att testa billboardskaraktärer på detta sätt i en större miljö och/eller använda videotexturer istället för bilder.

  • 290.
    Bäck, Gustaf
    et al.
    University of Skövde, School of Engineering Science.
    Wall, Gustaf
    University of Skövde, School of Engineering Science.
    Effektiv Materialhantering: Konstruktion och hållfasthetsberäkning av materialhanteringslösning2014Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The company Furhoffs Rostfria AB located in Skövde has developed a new assembly method for kitchen-sinks. The method means a more effective assembly of kitchen-sinks but the transportation of the material to be assembled is still a moment requiring a lot of time. The goal of this work is to develop a material handling concept that facilitates this transport. To confirm the achievement of the set goal, a number of more specific goals are also set. These goals should be achieved for the most optimal solution regarding the number of work moments, time regarding usage, general requirements from the Swedish Work Environment Authority and requirements regarding sustainable development.

    To understand the functions that the concept should fulfill and to understand the ingoing parameters, a literature study is performed. The study is based on a number of sources including current scientific articles which represents the foundation regarding the method for sustainable development. Web sources, books with technical character and knowledge from Furhoffs Rostfria AB are used as a foundation for the remaining methods performed. The final concept satisfies four functions, to transport, to lift, to hold and to assort ingoing material.

    Different basic concepts are produced by using three different methods of generation of concepts, where different competences are included. A weighted concept selection matrix is used to select which concept that should be analyzed further. The chosen concept is analyzed regarding; the risk of tipping, items placed on the concept sliding around and the strength and the mechanics of the concept.

    The material strength analysis, performed by using the finite element method, evaluates acting moments, acting effective stresses and deformation of the concept. The concept is evaluated by creating a beam element analysis and by creating a shell element analysis. The conclusion from these analyzes is that, regarding the practical usage of the concept, an insignificant deformation is obtained. Regarding occurring effective stresses a safety factor of barely two is obtained compared to the yield limit of the chosen material.

    The concept fulfills all the goals and demands set and is evaluated as a functioning solution for the stated problem. Suggestions regarding further future improvements for the chosen concept are provided.

  • 291.
    Bäckstrand, Gunnar
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Information Flow and Product Quality in Human Based Assembly2009Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Information is an important part of the manual assembly process. Information provides the user with the means to fulfil assembly tasks so that the right quality as well as high productivity are accomplished. This thesis addresses issues connected to information and information use in a modern manual assembly environment, and how these issues affect human operators, quality and productivity. The overall objectives of the research were to gain further knowledge on how attention affects the internal reject rate, to investigate these phenomena in industrial and laboratory environments and finally to propose a suitable evaluation method to be utilised at the design stage of an information system.

    Studies were performed with the purpose of investigating how the assembly personnel were affected by the information and how it affected quality and productivity. The studies were performed in an assembly plant and in the laboratory. Quantitative data collection included 10 days and nights of production where the information impact on quality was investigated. Connected to this study was a qualitative survey performed among 171 persons from the assembly personnel. The laboratory study took place during three days, approximately eight hours each day. It involved 30 persons, all experienced assembly workers from the reference assembly plant. The focus of this study was how information affected the personnel and thereby the productivity.

    The findings revealed that information affected the quality rates and productivity and that this can be linked to how the information is presented as well as when the information is presented. It was possible to link these findings to the outcome of a successful information search process, and to conclude that a use of an evaluation method or work process during the product lifecycle could have made it possible to avoid some of the problems connected to the information presentation. This is the basis for a proposed pragmatic evaluation method. The method was tested as a support system during the design of a prototype user interface to be used at the pilot plant.

    The major contribution of this research is the connection between attention and quality as well as the connection between attention and productivity. Knowledge regarding the importance of presenting the information at the right time must also be regarded as an important and proven contribution.

  • 292.
    Bäckstrand, Gunnar
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre.
    Intuitiv montering2012In: Teknik och tillväxt, no 2, p. 24-24Article in journal (Other (popular science, discussion, etc.))
  • 293.
    Bäckstrand, Gunnar
    et al.
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre. Swerea IVF AB, Stockholm.
    Bergman, Christian
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre.
    Högberg, Dan
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre.
    Moestam, Lena
    Volvo Trucks GTT, Gothenburg.
    Lean and its impact on workplace design2013In: Proceedings of NES 2013, 45th Nordic Ergonomics & Human Factors Society conference, Iceland, August 2013, 2013Conference paper (Refereed)
    Abstract [en]

    Lean analyses and following corrections of workstations are typically performed reactively, i.e. solving problems that already exist. However, there are benefits of enhanced proactivity related to the consideration of lean and human factors, as this would reduce the need for updating workstations. The approach presented here utilises a company specific, reactive lean evaluation methodology, but applied proactively, in the workstation design phase. Results gave that many assessment items in fact can be proactively addressed. This way, ergonomic and lean workstations that support quality, performance and wellbeing for a diversity of workers, can be built right the first time.

  • 294.
    Bäckstrand, Gunnar
    et al.
    Volvo Powertrain.
    Brolin, Anna
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Högberg, Dan
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Case, Keith
    Loughborough University.
    Supporting Attention in Manual Assembly and its Influence on Quality2010In: Proceedings of the 3rd Applied Human Factors and Ergonomics (AHFE) International Conference / [ed] Gavriel Salvendy, Waldemar Karwowski, Louisville: AHFE International , 2010Conference paper (Refereed)
    Abstract [en]

    Modern manufacturing information systems allow fast distribution of, and access to, information. One of the  main purposes with an information system within  manual assembly is to improve product quality, i.e. to ensure that assembly errors are as few as possible. Not only  must an information system contain the right information, it must  also  provide  it  at  the  right  time  and  in  the  right  place.  The  paper  highlights some of the concerns related to the design and use of information systems in manual assembly.  The  paper  describes  a  study  that  focuses  on  the  correlation  between active information seeking behaviour and assembly errors. The results are founded on  both  quantitative  and  qualitative  methods.  The  study  indicates  that  by  using simplified information carriers, with certain characteristics, the assembly personnel more easily could interpret the information, could to a higher degree be prompted (triggered) about product variants and could also be able to prepare physically and mentally   for   approaching   products   arriving   along   the   assembly   line.   These conditions  had  positive  influence  on  quality,  i.e.  gave  a  reduction  of  assembly errors.

  • 295.
    Bäckstrand, Gunnar
    et al.
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Högberg, Dan
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Variants = Customer value?2010In: Standards News Magazine, no 2, p. 17-19Article in journal (Other (popular science, discussion, etc.))
  • 296.
    Bäckstrand, Gunnar
    et al.
    University of Skövde, School of Technology and Society.
    Lämkull, Dan
    Volvo Car Corporation, Manufacturing Engineering, Gothenburg, Sweden / Department of Product and Production Development, Chalmers University of Technology, Gothenburg, Sweden.
    Högberg, Dan
    University of Skövde, School of Technology and Society.
    De Vin, Leo J.
    University of Skövde, School of Technology and Society.
    Case, Keith
    University of Skövde, School of Technology and Society.
    Reduction of ergonomics design flaws through virtual methods2007In: Proceedings of the 39th annual Nordic Ergonomic Society Conference, Lysekil, Sweden, October 1-3, 2007 (NES 2007) CD-ROM, Nordic Ergonomics Society, 2007Conference paper (Refereed)
    Abstract [en]

    A work method for product and production system development that includes virtual methods for ergonomics analysis is presented and argued.The proposed work method is described and illustrated with an example,which the authors believe shows how a virtual work method can contribute to a better workplace design, and thereby, if utilised, would have prevented some of the design flaws that existed in the actual final product design in the example. This paper will also present the outcome, gain, and setbacks that are connected to the use of virtual work analysis methods within a design process.

  • 297.
    Bäckstrand, Gunnar
    et al.
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre. Swerea IVF.
    Thorvald, Peter
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre.
    Nylén, Ulf
    University of Skövde, External Relations and Communication Office.
    Flexibel montering möter industrins utmaningar2013In: Teknik och tillväxt, no 3, p. 5-Article in journal (Other (popular science, discussion, etc.))
  • 298.
    Bältsjö, Ivar
    University of Skövde, School of Humanities and Informatics.
    Interaktiv manual för en fysisk produkt: Hur interaktivitet påverkar instruktioner för skapandet av en fysisk produkt.2013Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Denna undersökning syftar till att undersöka huruvida interaktivitet kan göra instruktioner för en fysisk uppgift mer effektiva. För att göra detta skapades två applikationer som instruerade i vikningen av en origamifigur i form av en båt. En version implementerade interaktiva element medan den andra inte gjorde det. Testpersoner fick genomföra halva uppgiften med vardera applikationen och sedan fylla i en enkät. Inga definitiva svar hittades i undersökningen, men den skulle kunna användas som grund eller inspiration för vidare forskning.

  • 299.
    Calestam, Magnus
    et al.
    University of Skövde, School of Technology and Society.
    Wedin, Johan
    University of Skövde, School of Technology and Society.
    Bucklingsanalys av spannmålssilo2013Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Grains with varying humidity can be stored in square silos with wall elements consisting of corrugated sheet. When the stored grain is to be emptied from the silos it has tendency to stick to the walls, especially if humid, which means that the grain must be removed manually. To avoid this time-consuming process a flat sheet is mounted on the corrugated sheet to prevent the moist grain from sticking to the wall. If the same dimension on the corrugated sheet is used when the flat sheet is or is not mounted the walls may be subjected to buckling. This thesis is thus about how the wall elements shall be designed in order to prevent buckling. The silos that have been examined have a cross section of 3.0 x 3.0 m and 2.5 x 2.5 m respectively with wall elements consisting of only corrugated sheet or smooth sheet mounted on corrugated sheet. Furthermore, the silos got vertical walls with a height of 8.4 m consisting of ten sections. Calculations are made with wheat as the stored grain.

     

    To be able to dimension the wall elements the pressure is calculated for the different silos, using the Swedish and European standard Eurocode (2006), EN 1991-4 for pressure calculations in silos and tanks. To calculate the pressure the silos are assigned into action assessment class 1, since their capacity are less than a 100 tons, which further means that the unsymmetrical pressure can be ignored. The silos are also classified as slender. As the silos outlet consists of a square pyramidal hopper with centric outlet and a half internal angel of 45° an inner pipe flow occurs during emptying. This means according to Eurocode that the dimension shall be based on the pressure which occurs during filling. The horizontal and vertical pressure and the pressure made from the friction are calculated for the different cross sections.

     

    The CAD software Pro Engineer and the finite element extension Mechanica is used to model the current silos and perform analysis for stress and buckling. The models have four symmetry planes therefore only one eighth of the current structure is modeled, corresponding to half a wall element and half a pole. The models are created as shell models and boundary conditions are applied in all symmetrical planes and on the top and bottom of the pole. The structure of the silos is simplified since no screws or radius is modeled. The pressure calculated according to Eurocode is converted into forces and applied to the models. The whole structure is modeled in steel with yield strength of 180 MPa.

     

    The company’s older dimension standards are applied on the wall elements and analyzed. To investigate where to most critical areas for buckling occurs a buckling analysis based on a static analysis of the models is performed. The results from the buckling analysis for the silo wall element consisting of corrugated sheet with the width of 3.0 m shows that buckling occurs on the second bottom section at 72 % of the applied force. For the silo consisting of the same wall element but with the width of 2.5 m buckling occurs at the top section where the buckling force amounts to 62 % of the applied force. For the silos with wall elements consisting of plain sheet mounted on corrugated sheet buckling occurs at 3-4 % of the applied force for the two wall widths. Analysis show that the low values of buckling load on the plane sheet is a result from local buckling. In order to dimension the corrugated sheet to prevent it from buckling when the plane sheet is mounted a free body diagram is made for the corrugated sheet to obtain the acting forces. The buckling analysis of the corrugated sheet, with wall width 3.0 m, which is pressurized by the plane sheet shows that buckling occurs on the silos second bottom section. Buckling occurs at 59 % of the applied force for the silo with wall width of 2.5 m buckling occurs at 51 % of the applied force on the silo top section.

     

    Since the goal is that the corrugated sheets are not to be subject to buckling, the thickness of the sheets is iterated until the buckling force is equal to at least 110 % of the applied force. This generates an increased thickness for the lower four sections for the silo with wall element consisting of corrugated sheet with wall width of 3.0 m. For the silo with the same wall elements but with a wall width of 2.5 m, the dimensions of the top two sections need to increase. Regarding the silos with wall elements consisting of plane sheet mounted on corrugated sheet an increase in dimension is needed for the corrugated sheet for the five lowest sections for the wall width of 3.0 m.

     

    With a wall width of 2.5 m the same dimension can be used as when the silo wall elements consist of only corrugated sheet. If the plane sheet is not to be exposed for buckling the thickness of the sheets needs to be increased from between 5.5 mm and 1.5 mm. All calculations of the sheet dimensions are obtained by a conservative thinking which means that the company’s older dimensions may be correct. However, the resulting dimensions are reasonable for the corrugated sheets.

     

  • 300.
    Camacho Moreno, Dionisio
    et al.
    University of Skövde, School of Engineering Science.
    Giner Pérez, Jorge
    University of Skövde, School of Engineering Science.
    Mechanical Design of a Compliant Horseshoe2014Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The principal aim of this research is the design of a more compliant horseshoe which allows the natural expansion and compression of the horse hoof. Three different simulations have been carried out in by using Finite Element Method in order to know the behaviour of the horse hoof when is analysed under the same load conditions. First the hoof will be studied without any horseshoe to obtain the produced displacement by the hoof expansion. Once the displacement of the barefoot hoof is known, an assembly, in which a sample stiff horseshoe is attached to the hoof by nails, will be performed to obtain both the hoof displacement as the horseshoe one. Finally, after three different researches about the current horseshoes, different possible alternative materials and most commons attachment methods, a more flexible horseshoe will be created and analysed. The results obtained in the three simulations will be compared and commented. 

3456789 251 - 300 of 1603
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf