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  • 1451.
    Torra, Vicenc
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Some properties of Choquet integral based probability functions2015In: Acta et Commentationes Universitatis Tartuensis de Mathematica, ISSN 1406-2283, E-ISSN 2228-4699, Vol. 19, no 1, p. 35-47Article in journal (Refereed)
    Abstract [en]

    The Choquet integral permits us to integrate a function with respect to a non-additive measure. When the measure is additive it corresponds to the Lebesgue integral. This integral was used recently to define families of probability-density functions. They are the exponential family of Choquet integral (CI) based class-conditional probability-density functions, and the exponential family of Choquet– Mahalanobis integral (CMI) based class-conditional probability-density functions. The latter being a generalization of the former, and also a generalization of the normal distribution.

    In this paper we study some properties of these distributions, and study the application of a few normality tests.

  • 1452.
    Torra, Vicenc
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Transparency and Disclosure Risk in Data Privacy2015In: Proceedings of the Workshops of the EDBT/ICDT 2015 Joint Conference (EDBT/ICDT) / [ed] Peter M. Fischer, Gustavo Alonso, Marcelo Arenas, Floris Geerts, 2015, p. 246-Conference paper (Other academic)
    Abstract [en]

    k-Anonymity and differential privacy can be considered examples of Boolean definitions of disclosure risk. In contrast, record linkage and uniqueness are examples of quantitative measures of risk. Record linkage is a powerful approach because it can model different types of scenarios in which an adversary attacks a protected database with some information and background knowledge. Transparency holds in data privacy when data is published together with details on their processing. This includes the data protection method used and its parameters. Intruders can use this information to improve their attacks. Specific record linkage algorithms can be defined to take into account this information, and to define more accurate disclosure risk measures. Machine learning and optimization techniques also permits us to increase the  effectiveness of record linkage algorithms. This talk will be focused on disclosure risk measures based on record linkage. We will describe how we can improve the performance of the algorithms under the transparency principle, as well as using machine learning and optimization techniques.

  • 1453.
    Torra, Vicenc
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Transparency and microaggregation2015In: UNECE SDC 2015, 2015Conference paper (Other academic)
    Abstract [en]

    Transparency has an important effect on disclosure risk. In general, masking methods have to be evaluated taking into account that intruders can use all available information to attack the data. When the masking method as well as their parameters are disclosed, this information can also be used by an intruder. In this talk we will review results on the effects of transparency in disclosure risk assessment for microdata giving special emphasis to microaggregation.

  • 1454.
    Torra, Vicenç
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    A fuzzy microaggregation algorithm using fuzzy c-means2015In: Artificial Intelligence Research and Development / [ed] Eva Armengol, Dionís Boixader, Francisco Grimaldo, IOS Press, 2015, p. 214-223Conference paper (Refereed)
    Abstract [en]

    Masking methods are used in data privacy to avoid the disclosure of sensitive information. Microaggregation is a perturbative masking method that has been proven effective. Data masked using microaggregation can be attacked when the intruder has information of the masking method and the parameters used. Publishing this information is usual under the transparency principle. Fuzzy microaggregation was introduced a few years ago to avoid this type of transparency attacks. In this paper we propose a new simpler method for microaggregation based on fuzzy c-means. We discuss the effectiveness of the approach. One of the advantages of this approach is its computational complexity.

  • 1455.
    Torra, Vicenç
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Derivation of Priorities and Weights for Set-Valued Matrices Using the Geometric Mean Approach2015In: Applied Artificial Intelligence, ISSN 0883-9514, E-ISSN 1087-6545, Vol. 29, no 5, p. 500-513Article in journal (Refereed)
    Abstract [en]

    Priorities are essential in the analytic hierarchy process (AHP). Several approaches have been proposed to derive priorities in the framework of the AHP. Priorities correspond to the weights in the weighted mean as well as in other aggregation operators as the ordered weighted averaging (OWA) operators, and the quasi-arithmetic means.

    Derivation of priorities for the AHP typically starts by eliciting a preference matrix from an expert and then using this matrix to obtain the vector priorities. For consistent matrices, the vector of priorities is unique. Nevertheless, it is usual that the matrix is not consistent. In this case, different methods exist for extracting this vector from the matrix.

    This article introduces a method for this purpose when the cells of the matrix are not a single value but a set of values. That is, we have a set-valued preference matrix. We discuss the relation of this type of matrices and hesitant fuzzy preference relations.

  • 1456.
    Torra, Vicenç
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    On the selection of m for Fuzzy c-Means2015In: Proceedings of the 2015 Conference of the International Fuzzy Systems Association and the European Society for Fuzzy Logic and Technology / [ed] José M. Alonso, Humberto Bustince & Marek Reformat, Paris: Atlantis Press , 2015, p. 1571-1577Conference paper (Refereed)
    Abstract [en]

    Fuzzy c-means is a well known fuzzy clustering algorithm. It is an unsupervised clustering algorithmthat permits us to build a fuzzy partition from data. The algorithm depends on a parameter m whichcorresponds to the degree of fuzziness of the solution. Large values of m will blur the classes andall elements tend to belong to all clusters. The solutionsof the optimization problem depend on theparameter m. That is, different selections of m willtypically lead to different partitions. In this paper we study and compare the effect ofthe selection of m obtained from the fuzzy c-means.

  • 1457.
    Torra, Vicenç
    et al.
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Guillen, Montserrat
    Department of Econometrics, Riskcenter-IREA, University of Barcelona, Spain.
    Santolino, Miguel
    Department of Econometrics, Riskcenter-IREA, University of Barcelona, Spain.
    Continuous m-dimensional distorted probabilities2018In: Information Fusion, ISSN 1566-2535, E-ISSN 1872-6305, Vol. 44, p. 97-102Article in journal (Refereed)
  • 1458.
    Torra, Vicenç
    et al.
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Narukawa, Yasuo
    Distances on non-additive measures using the numerical Choquet integrale2015In: The 12th International Conference on Modeling Decisions for Artificial Intelligence: CD-ROM Proceedings, MDAI - HiS , 2015Conference paper (Refereed)
  • 1459.
    Torra, Vicenç
    et al.
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Narukawa, YasuoToho Gakuen, Tokyo, Japan.
    Modeling Decisions for Artificial Intelligence: 12th International Conference, MDAI 2015, Skövde, Sweden, September 21-23, 2015, Proceedings2015Conference proceedings (editor) (Refereed)
  • 1460.
    Torra, Vicenç
    et al.
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Narukawa, Yasuo
    Toho Gakuen, Naka, Kunitachi, Tokyo, Japan.
    Numerical integration for the Choquet integral2016In: Information Fusion, ISSN 1566-2535, E-ISSN 1872-6305, Vol. 31, p. 137-145Article in journal (Refereed)
    Abstract [en]

    Choquet integrals with respect to non-additive (or fuzzy measures) have been used in a large number of applications because they permit us to integrate information from different sources when there are interactions. Successful applications use a discrete reference set. In the case of measures on a continuous reference set, as e.g. the real line, few results have been obtained that permit us to have an analytical expression of the integral. However, in most of the cases there is no such analytical expression. In this paper we describe how to perform the numerical integration of a Choquet integral with respect to a non-additive measure.

  • 1461.
    Torra, Vicenç
    et al.
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Narukawa, YasuoDahlbom, AndersUniversity of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    The 12th International Conference on Modeling Decisions for Artificial Intelligence: CD-ROM Proceedings2015Conference proceedings (editor) (Refereed)
  • 1462.
    Torra, Vicenç
    et al.
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre. IIIA-CSIC, Campus UAB s/n, Bellaterra, Catalonia, Spain.
    Narukawa, Yasuo
    Toho Gakuen, Kunitachi, Tokyo, Japan.
    Sugeno, Michio
    ECSC, c/ Gonzalo Gutiérrez Quirós s/n, Mieres, Spain.
    On the f-divergence for non-additive measures2016In: Fuzzy sets and systems (Print), ISSN 0165-0114, E-ISSN 1872-6801, Vol. 292, p. 364-379Article in journal (Refereed)
    Abstract [en]

    The f -divergence evaluates the dissimilarity between two probability distributions defined in terms of the Radon–Nikodym derivative of these two probabilities. The f -divergence generalizes the Hellinger distance and the Kullback–Leibler divergence among other divergence functions. In this paper we define an analogous function for non-additive measures. We discuss them for distorted Lebesgue measures and give examples. Examples focus on the Hellinger distance.

  • 1463.
    Torstensson, Niklas
    et al.
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Susi, Tarja
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Online sexual grooming and offender tactics -: What can we learn from social media dialogues?2015In: Proceedings of the 2015 Swecog Conference / [ed] Billing, E., Lindblom, J. & Ziemke, T., Skövde, 2015, Vol. 3, p. 23-23Conference paper (Refereed)
    Abstract [en]

    While online social networking sites and other digital media provide a means for positive online experiences, they are also being misused for offences like online sexual grooming. Attempts have been made to analyse and model online grooming in order to understand this kind of predator behaviour (e.g., O’Connell, 2004; Williams et al., 2013). This research, and the resulting models of the grooming process, is however, invariably based on material where adult decoys (e.g., researchers, law enforcement officers, adults trained to entrap offenders) pose as children in the interaction with potential offenders. We argue that such material, i.e., decoy-offender chat logs, does not reflect real grooming processes; Decoys have an underlying agenda to make prosecutable cases against offenders, which entails decoys resorting to manipulation tactics otherwise typical for offender behaviour. In all essence, this often leads to a dialogue with two adults using grooming tactics on each other, and the resulting models do not capture the patterns of child-offender dialogues.

    Contrary to previous research, we have analysed real-world child-offender chat logs from closed forums. Our data set, selected dialogues (ca. 500 pages) from a corpus of ca. 12 000 A4-pages was thematically analysed and categorised using NVivo 10 software. The coding was done by both authors for inter-rater reliability. Where coding differed, the authors explored the categorisation until agreement was reached (cf., Whittle et al., 2013). The material was also compared to decoy-offender chat logs (ca. 100 pages, publically available on perverted-justice.com).

    The analysis of the different data sets reveal quite different pictures of the grooming process. While previous models describe the grooming process as sequential (O’Connell, 2004) or thematic (Williams et al., 2013), our findings suggest a far more complex behavioural pattern – significantly diverse dialogue patterns with different tactics emerge, depending on whether the respondent is a decoy or a child, and their respective responses. The (preliminary) results show differences in both dialogue and process structure. Dialogues with decoys commonly show what can best be described as “artificial compliance”, presumably due to their underlying agenda of generating prosecutable cases. Furthermore, decoys tease out personal information from the offenders, and also share “personal” information about themselves, even when not asked for it.

    Child-offender dialogues instead show patterns of reluctance or objections to offender requests for personal information, suggestions of sexual nature, etc. Another offender tactic is threats to obtain compliance, which was not found in any of the analysed decoy-offender dialogues. Other deviations include differences in dialogue length, number of dialogue turns, and complexity, with regard to changes in topics and offender tactics. Further research is necessary for a more thorough understanding of online grooming, and new models are needed that reflect real-world grooming processes. This includes offender behaviours, reasoning, decisions, and tactics used in grooming. Further, such knowledge is of outmost importance for risk awareness measures for young people so they can better cope with online challenges and risks, and make sensible judgements and decisions in online interactions.

  • 1464.
    Tosthage, Lily
    University of Skövde, School of Informatics.
    Dissonans och spelares upplevelser: Spelares uppfattning av en medveten dissonans i en avatars och miljös formspråk2018Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Den här studien undersöker om en spelare skulle känna av en dissonans mellan en avatar med fredligt formspråk och en spelmiljö med aggressivt formspråk. En spelbar artefakt i form av ett 2D äventyrspel skapades med en runt utformad avatar ochspetsigt utformade fiender och miljöer där övriga faktorer försökte hållas neutrala. Fem testpersoner spelade igenom spelet och intervjuades för att ta reda på hur dekände och upplevde spelets olika delar. Resultatet antyder att spelarna inte kände av någon dissonans. Detta spekuleras bero på ett fokus på spelande och förutfattade meningar kring grafikens motiv. Framtida arbeten kan fokusera på fler element än bara formspråk för att överdriva uttrycken och undersöka om en starkare dissonans kan upptäckas av spelare.

  • 1465.
    Trapero, Juan R.
    et al.
    Department of Business Administration, Universidad de Castilla-La Mancha, Ciudad Real, Spain.
    García, Fausto. P.
    Department of Business Administration, Universidad de Castilla-La Mancha, Ciudad Real, Spain.
    Kourentzes, Nikolaos
    Department of Management Science, Lancaster University, Lancaster, United KingdomUK.
    Impact of demand nature on the bullwhip effect: Bridging the gap between theoretical and empirical research2014In: Proceedings of the Seventh International Conference on Management Science and Engineering Management / [ed] Jiuping Xu, John A. Fry, Benjamin Lev, Asaf Hajiyev, Springer, 2014, Vol. 242, no VOL. 2, p. 1127-1137Conference paper (Refereed)
    Abstract [en]

    The bullwhip effect (BE) consists of the demand variability amplification that exists in a supply chain when moving upwards. This undesirable effect produces excess inventory and poor customer service. Recently, several research papers from either a theoretical or empirical point of view have indicated the nature of the demand process as a key aspect to defining the BE. Nonetheless, they reached different conclusions. On the one hand, theoretical research quantified the BE depending on the lead time and ARIMA parameters, where ARIMA functions were employed to model the demand generator process. In turn, empirical research related nonlinearly the demand variability extent with the BE size. Although, it seems that both results are contradictory, this paper explores how those conclusions complement each other. Essentially, it is shown that the theoretical developments are precise to determine the presence of the BE based on its ARIMA parameter estimates. Nonetheless, to quantify the size of the BE, the demand coefficient of variation should be incorporated. The analysis explores a two-staged serially linked supply chain, where weekly data at SKU level from a manufacturer specialized in household products and a major UK grocery retailer have been collected. 

  • 1466.
    Trapero, Juan R.
    et al.
    Lancaster University, Department of Management Science, United Kingdom.
    Kourentzes, Nikolaos
    Lancaster University, Department of Management Science, United Kingdom.
    Fildes, R.
    Lancaster University, Department of Management Science, United Kingdom.
    Impact of information exchange on supplier forecasting performance2012In: Omega: The International Journal of Management Science, ISSN 0305-0483, E-ISSN 1873-5274, Vol. 40, no 6, p. 738-747Article in journal (Refereed)
    Abstract [en]

    Forecasts of demand are crucial to drive supply chains and enterprise resource planning systems. Usually, well-known univariate methods that work automatically such as exponential smoothing are employed to accomplish such forecasts. The traditional Supply Chain relies on a decentralized system where each member feeds its own Forecasting Support System (FSS) with incoming orders from direct customers. Nevertheless, other collaboration schemes are also possible, for instance, the Information Exchange framework allows demand information to be shared between the supplier and the retailer. Current theoretical models have shown the limited circumstances where retailer information is valuable to the supplier. However, there has been very little empirical work carried out. Considering a serially linked two-level supply chain, this work assesses the role of sharing market sales information obtained by the retailer on the supplier forecasting accuracy. Weekly data from a manufacturer and a major UK grocery retailer have been analyzed to show the circumstances where information sharing leads to improved forecasting accuracy. Without resorting to unrealistic assumptions, we find significant evidence of benefits through information sharing with substantial improvements in forecast accuracy. 

  • 1467.
    Trapero, Juan R.
    et al.
    Universidad de Castilla-La Mancha, Ciudad Real, Spain.
    Kourentzes, Nikolaos
    Lancaster University, Lancaster, United Kingdom.
    Fildes, Robert
    Lancaster University, Lancaster, United Kingdom.
    On the identification of sales forecasting models in the presence of promotions2015In: Journal of the Operational Research Society, ISSN 0160-5682, E-ISSN 1476-9360, Vol. 66, no 2, p. 299-307Article in journal (Refereed)
    Abstract [en]

    Shorter product life cycles and aggressive marketing, among other factors, have increased the complexity of sales forecasting. Forecasts are often produced using a Forecasting Support System that integrates univariate statistical forecasting with managerial judgment. Forecasting sales under promotional activity is one of the main reasons to use expert judgment. Alternatively, one can replace expert adjustments by regression models whose exogenous inputs are promotion features (price, display, etc). However, these regression models may have large dimensionality as well as multicollinearity issues. We propose a novel promotional model that overcomes these limitations. It combines Principal Component Analysis to reduce the dimensionality of the problem and automatically identifies the demand dynamics. For items with limited history, the proposed model is capable of providing promotional forecasts by selectively pooling information across established products. The performance of the model is compared against forecasts provided by experts and statistical benchmarks, on weekly data; outperforming both substantially.

  • 1468.
    Traspaderne Vitoria, Vidal Roa, Txaber, Erlaiz
    University of Skövde, School of Technology and Society.
    WISE SHOP FLOOR DECISION SUPPORT SYSTEM2012Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
  • 1469.
    Treijner, Christofer
    et al.
    University of Skövde, School of Technology and Society.
    Svensson, Mattias
    University of Skövde, School of Technology and Society.
    Experimentell studie av reversibel axialfläkt: Med avseende på utformning av nav/skovelbas samt minsta/största skovelvinkel2012Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    In this thesis a new construction of a reversible axial flow fan is being studied. By performing experiments on different variants of a fan wheel an evaluation is done. Factors to be varied are the design of the hub and the blade base as well as blade angle. All tests is performed in a test rig established by AB Akron-maskiner. The test rig is constructed according to ISO 5801.

    Experiments show that the hub design itself does not have a significant impact on the performance. Changes in performance are detected when various combinations of hubs and blade base are tested. The greatest difference in efficiency between the best and worst hub/blade base combination is about 20%. It is of great interest to have access to this information because a simpler design of the hub allows greater flexibility in the manufacturing. An upper limit for the maximum blade angle is partly due to the appearance of stall but mainly the limitations of the fan motor. The minimum blade angle has also the result founding in engine size. The performance is improved if the radial airflow through the blades cavity is blocked. A blockage causes an increase in efficiency by 5-12% and a reduction in sound power level of 2-3 dB. For optimal performance, the design of the hub should be spherical and the blade base curved and shaped to the hub. This is the same type of hub that is produced today. Maximum and minimum useful blade angle is 50° and 25° to the rotation direction.

  • 1470.
    Trengereid, Erik
    et al.
    University of Skövde, School of Technology and Society.
    Grönborg, Lucas
    University of Skövde, School of Technology and Society.
    Hållbart Inköp: Hur inköpsfunktionen kan bidra till en hållbarare organisation2012Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The purpose of this study is to analyze how the purchasing function can contribute to a com-pany’s sustainable performance in both the short and long term. Furthermore, the purpose is also to scrutinize how Swedish firms use sustainable procurement today. The study examines that by comparing an empirical investigation of Swedish firms made by the authors to the theoretical frameworks preferred way of working with sustainable procurement, which is es-sentially based on 41 journal articles. This study is of interest since the purchasing function possesses one of the greatest opportunities to influence both the company and its suppliers; this indicates that procurement can play a major role in increasing sustainable development. The use of sustainable procurement can create many advantages for both the company practic-ing, and for the environment. Nonetheless, it is according to earlier studies clear that compa-nies are not taking advantage of the promises found in sustainable procurement. One potential reason companies are not utilizing sustainable procurement is that they lack the knowledge needed to execute a more sustainable purchasing method and also that firms consider sustain-able purchasing as complex and resource intensive.This study explains the fundamental concepts needed to utilize sustainable purchasing; these are green purchasing, social responsible buying and economical responsibility. The conjunc-tion of these three parts constitutes sustainable purchasing.The result of the study is a theoretical framework that highlights the possibilities of sustaina-ble purchasing and provides some overall guidelines for how the work towards it can be con-ducted. The theoretical framework also provides a compiling of the existing litterature to fa-cilitate further studies. The study shows that there exist pure strategies for working towards both environmental and social sustainability. Pure strategies for purchasing towards economic sustainablility where still harder to come by. One clear recognition during the work with the theoretial framework were however that the different parts that makes up sustainable purchas-ing doesn't stand alone, they are rather interrelated. That indicates that it is better to work to-wards sustainability as an overall concept rather than towards its parts. The study also shows how six companies who purports to be working with sustainable procurement does so, and how this conforms to the literature, and how it does not. The found literature on the subject frequently mentions that the biggest problem with sustainable procurement today is compa-nies generally low involvement in sustainability. These problems where however harder to prove in the study. Based on the study, several factors that affect companies involvement in sustainable procurement was identified. Factors such as; company size, line of business, level of globalization proved to affect how the companies work with sustainable procurement.

  • 1471.
    Tressing, Erik
    et al.
    University of Skövde, School of Engineering Science.
    Banck, Gustav
    University of Skövde, School of Engineering Science.
    Utveckling av laddstolpe med befintlig elektronik2019Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    During this project you will see the process behind the development of a charging station for electric vehicles with electronics developed by Sea Ice AB. Sea Ice AB wanted two concepts, one accessory that would allow installations of a charging box without access to a wall. Also a concept of a charging pole. These concepts had to be discreet, and blend in with the surrounding environment, which will be the niche for the produkt. The needs and desires from the user became a central topic for the project. In the prestudy these were found using forms, observations and other methods. The ideageneration were performed on the problems “form, cablemanagement, and function” which later will be welded together and solve the problem as a whole. Mockups, user tests and creative thinking were heavily used during the ideation phase. The project is summarized, evaluated, and communicated with CAD-models and an appearance prototype. All parties are satisfied with the result but its still uncertain if it's going to produktion.

  • 1472.
    Trigo Algar, Antonio Rafael
    University of Skövde, School of Humanities and Informatics.
    Serious Games For Overcoming Phobias: The Benefits of Game Elements2014Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis analyses the benefits of applying game elements to a Virtual Reality application for overcoming phobias, with a special focus on acrophobia, i.e. the fear of heights. Two different prototypes using the Oculus Rift head-mounted display were developed with a gradually exposure to heights. Both prototypes shared the same acrophobic scenario, but one included extra features from games such as engagement, motivation or goals. Twenty-four participants, divided into two groups of twelve, with moderate aversion to heights tested the prototypes. The participants’ heart rate and the time that they looked down from high altitudes were also measured and evaluated. The study showed slightly higher results regarding motivation for the prototype which included the additional game elements. Future studies should include a different head-mounted display, which would allow a longer time of play without motion sickness, and the participation of people diagnosed with acrophobia.

  • 1473.
    Troitiño Malavasi, Bruno Matias
    et al.
    University of Skövde, School of Technology and Society.
    Muñoz Llerena, Alejandro
    University of Skövde, School of Technology and Society.
    Hypothesis test of a new line balancing approach with dynamic allocation of assembly operations2013Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Assembly lines are no longer systems designed to produce as much as possible at the lower cost. Nowadays several factors such as mass customization and variation in demand have led the manufacturers to consider the flexibility of the assembly systems as one of the most important facts to take into account when designing an assembly line.

    In this context, this study attempts to test a new paradigm of the workload balance, which is based on a dynamic allocation of the assembly operations. In order to test the hypothesis, a real assembly system of engines has been used as a base model to implement the new approach. The work developed, uses the simulation as a means to carry out the study, which has required the development of several simulation scenarios. The hypothesis has been studied from two different approaches; on one hand a total dynamic allocation of assembly operations, which was expected to cause a wide operational range of the stations. On the other hand, the second approach implements a flow control which aims to reduce the operational range and workload fluctuations.

    The results obtained show a significant improvement of the system performance in comparison with the current assembly line. It has been found that any improvement implemented in the system is directly reflected in the total performance of the line, regardless if the improvement is made in a system constraint. Moreover, the results have proven a better response of the system to changes in the frequency of models production. 

    Finally, based on the results, this study suggests several paths of future work in order to acquire the needed information to implement the hypothesis in the real world context.

  • 1474.
    Tudero, Aitor
    et al.
    University of Skövde, School of Engineering Science.
    Azkue, Julen
    University of Skövde, School of Engineering Science.
    Emulation of a manufacturing process: Focusing on maintenance and operator training2017Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Having well-trained operators is a crucial need for Volvo Group Truck Operations (GTO). Mistakes from the factory staff may cause the production line to stop, and lead to economic losses. For this reason, Volvo GTO has decided to investigate the possibility of creating an emulation model from the production line and using it to train operators and maintenance personnel. The aim of this thesis is to develop an Operator Training Station (OTS) for the OP035 of the Volvo GTO Production Line 6. In the first part, a literature research was conducted, from which the authors gained insight into related fields such as emulation, virtual environments, and operator training. After that, an emulation model of theOP035 was created using some hardware from the factory. The real PLC program was analyzed and then modified in order to implement it to the emulation model. Then, communications were established between the different parts; emulation model and PLC program. Finally, a research of the common failures and problems of the production line was carried out, with the aim of being able to reproduce them in the Operator Training Station. Once the OTS was implemented, several tests had undergone to validate its behavior. These experiments verified that the emulation model was an accurate representation of the real system and validated its appropriateness for the operator training application

  • 1475.
    Tyborn Axt, Robert
    University of Skövde, School of Humanities and Informatics.
    Transdiegesis: En undersökning av de transdiegetiska ljudens problematik inom dataspel utifrån befintlig teori.2013Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
  • 1476.
    Tyborn Axt, Robert
    University of Skövde, School of Humanities and Informatics.
    Transdiegesis: En undersökning av de transdiegetiska ljudensproblematik inom dataspel utifrån befintligteori.2013Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
  • 1477.
    Tykal, Martin
    et al.
    Aalto University, Finland.
    Montebelli, Alberto
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Kyrki, Ville
    Department of Electrical Engineering and Automation, Aalto University, Finland.
    Incrementally Assisted Kinesthetic Teaching for Programming by Demonstration2016In: Human-Robot Interaction (HRI), 2016 11th ACM/IEEE International Conference on: HRI 2016, IEEE Computer Society, 2016, p. 205-212Conference paper (Refereed)
  • 1478.
    Téllez Segura, Alejandro
    University of Skövde, School of Engineering Science.
    Redesign of a wireless remote control: Joystick for industrial environments2014Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The present work has as aim the fulfilment of redesigning an existing housing for a wireless remote control. This project is carried out in cooperation with the company Tele-Radio AB, which develops, manufactures and markets radio control systems for industrial use. The new intended version must improve its predecessor by fulfilling detailed requirements and needs that have been researched throughout the project. The main followed method is the Engineering design process. It is compiled on the subsequent stages: definition of the problem, background study, requirement specifications, creative methods for generating ideas, concept selection, prototype and communication of results. In general, it has been developed a redesign version with bigger dimensions and implemented new features. These new features are focused on the top surface working area of the remote control; it has been designed with enough space for at least three joysticks and more than two switches of the same measures. Handles have experienced an enhancement in terms of ergonomics and also are adapted for being used whilst wearing industrial gloves. Innovative aesthetic and functionality have been taken into account.

  • 1479.
    Udén, Emelie
    et al.
    University of Skövde, School of Engineering Science.
    Westerberg, Sara
    University of Skövde, School of Engineering Science.
    Utveckling av hygienisk golvränna2017Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    AB Furhoffs Rostfria was founded in Skövde in 1899 to produce pots and cauldrons in copper. Today´s production is focused on products for HVAC (heating, ventilation and air conditioning) as well as for restaurant kitchens and customized products. The production is located in Skövde with machines suited for processing stainless steel.

    Demands from the market as well as Furhoff´s competitors are focusing on hygienic floor drain gutters. Because of this, Furhoffs wants to be the leading company of this kind of development. This project aims to develop a floor drain gutter that is suitable for environments with high requirements of hygiene to prevent spreading of diseases. These environments can be food factories, laboratories, hospitals and restaurant kitchens. The product needs to be safe to use in industries where traffic from heavy vehicles occur. This means that the product must withstand a load of 12 500 kg.

    To adjust the product to fit the user, interviews were performed in a large dairy, a food factory and in a restaurant. An observation was also performed in the restaurant to observe the cleaning process of a floor drain gutter. The information from the user study resulted in a list of needs. These, combined with demands from the company, formed the product specification. This specification was the basis for how the product later was developed. The components of the floor drain gutter, gully with a stench trap, gutter, cover and strainer basket, was developed separately and adapted to each other. Tests and cost analysis were performed to make well-founded concept choices. Water flow and removal of waste was tested to choose the most optimal gutter profile. To make sure the floor drain gutter is safe to use in the intended environment, load tests, slip tests and tests of flow rates were made.   

    The final product is adjusted for Furhoff´s production methods. The floor drain gutter fulfils the requirements and is suitable for environments with high hygiene demands. The result from this thesis will be used for further development of Furhoff´s future floor drain gutter. 

  • 1480.
    Ujvari, Sandor
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre.
    Proceedings of the Plan Research Conference2010Conference proceedings (editor) (Other academic)
  • 1481.
    Ujvari, Sandor
    et al.
    University of Skövde, School of Technology and Society.
    Hilmola, Olli-Pekka
    Kouvola Research Unit, Lappeenranta University of Technology, Kouvola, Finland.
    Advanced manufacturing simulation: Minor system details can be major issues in the real world2006In: Industrial management + data systems, ISSN 0263-5577, E-ISSN 1758-5783, Vol. 106, no 8, p. 1166-1186Article in journal (Refereed)
    Abstract [en]

    Purpose – This paper aims to highlight the complex nature of automated guided vehicle (AGV) simulation model building, and especially how system modelling details affect the end results. This is an important issue in all of the transportation simulation systems, since they are service-based by their nature, and additional inefficiencies create unanticipated performance downgrading.

    Design/methodology/approach – This paper uses a simulation approach, and simulated systems are based on a real-life case study and on well accepted hypothetical simulation example.

    Findings – Simulation system boundaries are often neglected in the model building, and especially interface to inbound (and possibly outbound) material flow should be considered carefully; based on these research results, AGV investments are seen in an entirely different light, as system boundary is enlarged to contain more realistically interacting elements. Similar system boundary issues were found from the case study: interface with overhead gantry did not provide near optimal performance. The case study also revealed that high speed of AGVs is not necessarily worth additional investment; constraints exist in safety, acceleration and ability to turn in corners.

    Research limitations/implications – The findings are based on the simulation work and, to see the real implications, real-life implementations on policy level are needed.

    Practical implications – Results of this research provide more insights for manufacturing unit investments, and especially in the scope of automated transportation system use. Also changes in manufacturing flow management issues, after investing in, for example, AGV systems, are different from in less-automated manufacturing units.

    Originality/value – This research work provides more insights to simulation research work, especially from the perspective of transportation systems. Also implications arising from case study are unique as being compared to previous research in the field.

  • 1482.
    Ujvari, Sandor
    et al.
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Hilmola, Olli-Pekka
    Kouvola Research Unit, Lappeenranta University of Technology, Kouvola, Finland.
    Semi-autonomous vehicles with routing flexibility: functionality and application areas2009In: International Journal of Services and Operations Management, ISSN 1744-2370, Vol. 5, no 4, p. 444-462Article in journal (Refereed)
    Abstract [en]

    Automated Guided Vehicle (AGV) systems are standard automated items in production and warehousing today. However, studies have rarely examined a more advanced form of AGVs called Semi-Autonomous Vehicles (SAVs), which have a higher sophistication of task completion and routing flexibility. This research presents SAVs in an industrial development case study. Using simulation, the route-keeping ability of SAVs with two types of guidance techniques is being studied. The results show that dual-navigation SAVs can provide the needed flexibility for routing. Using wire guidance and dead reckoning, both very well-established techniques, the SAVs' performance is, within certain limits, quite comparable to the AGVs with more advanced and expensive navigation techniques.

  • 1483.
    Ujvari, Sandor
    et al.
    University of Skövde, School of Technology and Society.
    Hilmola, Olli-pekka
    Kouvola Research Unit, Lappeenranta University of Technology, Kouvola, Finland.
    Simulation of Automatic Guided Vehicle systems in manufacturing environment: Case: Volvo's Crankshaft Unit in Skovde2008In: International Journal of Manufacturing Technology and Management (IJMTM), ISSN 1368-2148, E-ISSN 1741-5195, Vol. 15, no 1, p. 45-63Article in journal (Refereed)
    Abstract [en]

    Competing in global markets creates pressure for manufacturers to rigidly use automation, and advanced manufacturing techniques to improve manufacturing plant productivity. Among productivity, manufacturers are also interested about other performance dimensions, namely time, flexibility and quality. With the wise use of automation, we could directly improve all of the other indicators, and indirectly quality. In this paper it is shown, how implementation and use of Automatic Guided Vehicles (AGVs) could benefit from the use of manufacturing simulation. AGVs have been available for practical use since the 1970s, but still in the investment and use processes it is rarely seen justified to a high detail, what eventually determines the number of vehicles used in the system. Our paper is able to show with two simulation cases (a hypothetical example and a real case study) that the number of AGVs is very sensitive with respect to production system output. Furthermore, some assumptions that are often made can overly simplify the problem (e.g. no recharging of batteries and constant speed). Therefore, in this paper, we propose that more research should be addressed to the AGV system simulation, and in practice tools for decisions makers should be developed further. Our research also shows that empty travelling and low utilisation is a norm in current AGV systems in order to assure production system functionality, and there is a need and potential for performance improvement here, as well.

  • 1484.
    Unibaso Eguzkitza, Beñat
    et al.
    University of Skövde, School of Engineering Science.
    Ismail Dobón, Ismael
    University of Skövde, School of Engineering Science.
    Development of a flexible test platform utilizing gearbox simulators through programming2016Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A gearbox simulator is developed as platform for testing and demonstrating purposes. For that, a rig composed by a mechanical system and electronic equipment for controlling two servomotors is used. The objective of this equipment is to simulate the forces that the gearbox would transmit to the gear lever when the gear change operation is being carried-out. To reach this goal, a program is developed in LabVIEW to command the servomotors, emulating the forces by controlling the output torque and transmitting them to the gear stick as it would be in a real gearbox, taking into account real force-angle curves. Also, a graphical user interface is developed in order to monitor the simulator performance ad ease the way the data is chosen and introduced into the software.As seen in the experiment results, the graphs present similarities in shape and magnitude, which is important in regards of feeling; a better performance could be reach suppressing some system constraints.

  • 1485.
    Urenda Moris, Matias
    et al.
    University of Skövde, School of Technology and Society.
    Lezama, Thomas
    University of Skövde, School of Technology and Society.
    De Vin, Leo
    University of Skövde, School of Technology and Society.
    Robust design of a Maternity ward supported by discrete event simulation: a case study2007In: Proceedings of the 17th International Conference on Flexible Automation and Intelligent Manufacturing, FAIM 2007, 2007, p. 107-114Conference paper (Refereed)
  • 1486.
    Urenda Moris, Matias
    et al.
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre.
    Svensson, Jacob
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre.
    Simplification and aggregation strategies applied for factory analysis in conceptual phase using simulation2008In: Proceedings of the 2008 Winter Simulation Conference, IEEE conference proceedings, 2008, p. 1913-1921Conference paper (Refereed)
  • 1487.
    Urenda Moris, Matías
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Technology and Society.
    Dealing with variability in the design, planning and evaluation of Healthcare inpatient units: a modelling methodology for patient dependency variations2010Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This research addresses the fluctuating demand and high variability in healthcare systems. These system’s variations need to be considered whilst at the same time making efficient use of the systems’ resources. Patient dependency fluctuation, which makes determining the level of adequate staffing highly complex, is among the variations addressed. Dealing with variability is found to be a key feature in the design, planning and evaluation of healthcare systems.

    Healthcare providers are facing increasing challenges resulting from an aging population, higher patient expectancies, a shortage of healthcare professionals, as well as increasing costs and reduced funding. Despite the accentuated need for effective healthcare systems and efficient use of resources, many healthcare organisations are inadequately designed and, moreover, poorly managed. Hospital systems consist of complex interrelations between relatively small units, each of which is sensitive to stochastic variations in demand. In addition to this aspect of the system view, a critical resource for the patients’ wellbeing and survival is the staffing level of nurses. This puts the planning and scheduling of human resources as one of the system’s foremost aims. Current tools for staffing and personnel planning in healthcare organisations do not take into consideration the workload variations that result from the variable nature of patient dependency levels.

    The work presents the empirical findings of a number of case studies conducted at a regional hospital in Sweden. Principles and practical suggestions for the robust system design of inpatient wards using Discrete Event Simulation (DES) have been identified. Although DES techniques have, in principle, all the features for modelling the variation and stochastic nature of systems, DES has not been previously used for workload studies of inpatient wards. The main contribution of this work is therefore how a combination of DES and the data of Patient Classification Systems (PCSs) can be used to model workload variations and, subsequently, plan the nurse staffing requirements in systems with high variability. The work presented gives step by step guidance in how the analysis and subsequent modelling of an inpatient ward should be carried out. It defines a novel modelling methodology for patient dependency variations and length of stay modelling of a patient’s dependency progression, including an adaptation to the ward’s discharge figures. The modelling approach opens a novel way of analysing and evaluating the system design of inpatient wards.

  • 1488.
    Urenda Moris, Matías
    et al.
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre.
    Bernedixen, Jacob
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre.
    Goienetxea, Ainhoa
    University of Skövde, School of Technology and Society. University of Skövde, The Virtual Systems Research Centre.
    Diseño Y Análisis De Sistemas Productivos Utilizando La Optimización Mediante Simulación Basado En Internet2012In: Ingenieria Industrial, ISSN 0717-9103, E-ISSN 0718-8307, Vol. 11, no 1, p. 37-49Article in journal (Other academic)
  • 1489.
    Vahlgren, Simon
    University of Skövde, School of Engineering Science.
    Stopptidsanalys och standardiseringsförslag: Examensarbete på Semper AB2018Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The food processing company Semper AB in Götene has, after implementing software for monitoring production down time,identified a need for improvements considering time consumption in the cleaning process of Torn 4.After conducting studies, evaluations and analyses within the production, a need for standardization and time determination for the process has been identified. The project has resulted in propositions for new work standards considering time consumption for the included operations within the cleaning process, as well as definitions regarding the steps conducted parallel to one another to reduce the required time and streamline the process.The problem which was initially identified, as visualized through Semper’s down time tracking soft-ware Axxos, has through the course of the project been clarified as a symptom of a neglected work around standardization on the studied object. The need for increased standardization, control and planning is called for from both production management and operators alike, hence the competence involving the process exists within the organization, but need to emphasize and make use of it is nec-essary in a more efficient way.

  • 1490.
    Valerio Trujillo, Francisco Javier
    et al.
    University of Skövde, School of Technology and Society.
    Gallego Díaz, José Antonio
    University of Skövde, School of Technology and Society.
    DEVELOPMENT OF FURNITURE FOR SKÖVDE CULTURAL CENTRE2013Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Skövde Kulturhus is a cultural centre in Skövde that have been remodelled to incorporate new areas

    and to improve the old ones. The centre has different locals where different activities can be

    performed such as watching movies and theatre plays, dance, etc. In the art gallery, one of the new

    areas is the workshop, and for this, new furniture is needed. During the project, a set of a table and

    chairs have been developed for the workshop, following some specifications, set by the personnel of

    the Cultural Centre and by the conclusion from the different investigations.

    This report covers the whole process from the different researches to the evaluation and the

    development of the final concepts; it follows a modification of the Cyclic Strategy Method process,

    which includes the research and different design tools to create the concepts, as morphological chart,

    braindrawing and a study of the form. User studies have been made to get a good understanding of the

    way a person uses this furniture using surveys; ergonomics research has been made to design

    furniture for all kind of people; and market research have been made to discovered what kind of

    furniture is usually used. All these researches have been investigated to create the optimal table and

    chair for the activities done at the Centre. The final solutions, which have been evaluated against

    other concepts, are a wooden table, whose design and modular form permits to join other tables to

    work in teams; and a wooden chair, which have been designed for different people size. Both would

    fulfil the requirements and fit in the new cultural centre.

  • 1491.
    Vallgren, Frida
    University of Skövde, School of Humanities and Informatics.
    EN UNDERSÖKNING OMKOLLABORATIVT BETEENDE ISVÄRM AI: En jämförelse mellan tvåvägplaneringstekniker som skaparsamarbete mellan agenter.2012Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
  • 1492.
    van den Broeck, Adrian
    University of Skövde, School of Informatics.
    EVP, vitt brus och skrik2016Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
  • 1493.
    van Laere, Joeri
    et al.
    University of Skövde, School of Humanities and Informatics. University of Skövde, The Informatics Research Centre.
    Nilsson, Maria
    University of Skövde, School of Humanities and Informatics. University of Skövde, The Informatics Research Centre.
    Ujvari, Sandor
    University of Skövde, School of Technology and Society.
    Hilletofth, Per
    University of Skövde, School of Technology and Society.
    Reflections on fusion systems requirements analysis for maintenance planning2008In: Proceedings of the 2nd Skövde Workshop on Information Fusion Topics (SWIFT 2008) / [ed] H. Boström, R. Johansson, Joeri van Laere, Skövde: University of Skövde , 2008, p. 5-8Conference paper (Other academic)
  • 1494.
    Vandi, Poujan
    et al.
    University of Skövde, School of Engineering Science.
    Salomé, Joel
    University of Skövde, School of Engineering Science.
    Arbetssätt för att automatisera inhämtning av data till simuleringsmjukvaran FACTS2018Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
  • 1495.
    Vedin, Markus
    et al.
    University of Skövde, School of Engineering Science.
    Wik, Jonathan
    University of Skövde, School of Engineering Science.
    Styrning av visionkameror för positionsbestämning samt programmering av användargränssnitt: Försvarets materielverk FMV, Test & Evaluering2018Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis is accomplished in the Swedish Defence Materiel Administration, FMV in Karlsborg together with the University of Skövde. The thesis of 30 credits is within the main area automation technology.

    FMV in Karlsborg performs different tests of military systems. For one of these tests, industrial cameras are used to decide positions of objects. In order for FMV to operate these cameras they use a demo software which is controlled by laptops. The demo software can be improved because it contains several settings that are never used and also it is only adapted for the control of one camera. The hardware that controls the cameras can also be improved since requested frame rate is not achieved. The purpose of this thesis is to improve the existing hardware for collecting the images from the cameras and develop a new graphical user interface software for the cameras.

    To use the existing hardware better, information about the different parts of the computers have been collected to evaluate bottlenecks. This has been done by studying books and technical rapports and tests of the different computers. A software to control two cameras has been coded and a recommended platform has been described to FMV. The performance of the cameras has been improved with the new software and the steering of the cameras is now easier. 

  • 1496.
    Veld, Yolanda
    University of Skövde, School of Informatics.
    Locative Narratives with Digital Media2018Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The technologies used to guide along and inform about historic places and buildings have proliferated quickly, but it seems the application of these technologies in order to facilitate a powerful experience falls behind. With this thesis, the aim was to gain insights into how digital media can be utilized to create a media-conscious locative narrative and an engaging experience for cultural heritage. In this thesis examples of locative narratives with digital media for cultural heritage and the testing of two applications with a qualitative approach are discussed. The gained insights could help sophisticate and strategize thinking about storytelling with mobile digital technologies in order to find medium specific ways of guiding an audience and facilitate meaningful visitor experiences for cultural heritage.

    Keywords: locative narrative, mobile storytelling, digital media, multimodal, cultural heritage

  • 1497.
    Vennapusa, Siva Koti Reddy
    University of Skövde, School of Engineering Science.
    Design of bi-adhesive joint for optimal strength2019Independent thesis Advanced level (degree of Master (One Year)), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    To support the trust in the design development of adhesively bonded joints, it is important to precisely predict their mechanical failure load. A numerical simulation model with a two-dimensional linear elastic cohesive zone model using a combination of a soft and a stiff adhesive is developed to optimize the strength of a lap-joint. Separation under mixed-mode conditions (normal and shear direction) is considered. By varying the length of the adhesives, the fracture load is optimized. The results obtained from the numerical experiments show an improvement in strength.

  • 1498.
    Ventocilla, Elio
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Big Data programming with Apache Spark2019In: Data science in Practice / [ed] Alan Said, Vicenç Torra, Springer, 2019, p. 171-194Chapter in book (Refereed)
    Abstract [en]

    In this chapter we give an introduction to Apache Spark, a Big Data programming framework. We describe the framework’s core aspects as well as some of the challenges that parallel and distributed computing entail.

  • 1499.
    Ventocilla, Elio
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    On Making Machine Learning Accessible for Exploratory Data Analysis Through Visual Analytics2017Report (Other academic)
    Abstract [en]

    Visual Analytics is a field of study that seeks to aid human cognition in the process of analyzing data. It aims at doing so through visual interfaces and automated computations. Such automated computations often translate to Machine Learning algorithms. Users can leverage from these algorithms in order to find interesting patterns in massive and unstructured data. These algorithms are, however, still often regarded as black-boxes i.e. mathematical models which are hard to interpret and difficult to interact with. In a single Machine Learning library more than 40 variants of algorithms can be found, and some with up to 14 different parameters. The Visual Analytics community has pointed out a lack of research in helping users set parameters and compare results between algorithms. Moreover, it is argued that most technology in the field, which has aimed at bringing transparency to black-boxes, is embedded in domain-specific systems thus making it hard to reach and use for other users and in other domains. In general, Machine Learning has an accessibility challenge: it is hard to use, to interpret and, if not either of these, to reach. This research proposal motivates the need for research in making Machine Learning more accessible for exploratory data analysis, reviews existing work in the field, presents a research plan and, finally, describes preliminary results.

  • 1500.
    Ventocilla, Elio
    et al.
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Bae, Juhee
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Riveiro, Maria
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Said, Alan
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    A Billiard Metaphor for Exploring Complex Graphs2017In: Second Workshop on Supporting Complex Search Tasks / [ed] Marijn Koolen, Jaap Kamps, Toine Bogers, Nick Belkin, Diane Kelly, Emine Yilmaz, 2017, Vol. 1798, p. 37-40Conference paper (Refereed)
    Abstract [en]

    Exploring and revealing relations between the elements is a fre-quent task in exploratory analysis and search. Examples includethat of correlations of attributes in complex data sets, or facetedsearch. Common visual representations for such relations are di-rected graphs or correlation matrices. These types of visual encod-ings are often - if not always - fully constructed before being shownto the user. This can be thought of as a top-down approach, whereusers are presented with a full picture for them to interpret andunderstand. Such a way of presenting data could lead to a visualoverload, specially when it results in complex graphs with highdegrees of nodes and edges. We propose a bottom-up alternativecalled Billiard where few elements are presented at rst and fromwhich a user can interactively construct the rest based on whats/he nds of interest. The concept is based on a billiard metaphorwhere a cue ball (node) has an eect on other elements (associatednodes) when stroke against them.

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