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  • 17501. Xu, Peng
    et al.
    Shen, Jingchun
    Zhang, Xingxing
    University of Hull; University of Nottingham.
    Zhao, Xudong
    Qian, Yingchu
    Case study of smart meter and in-home display for residential behavior change in Shanghai, China2015In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 75, p. 2694-2699Article in journal (Refereed)
    Abstract [en]

    Smart meters and in-home displays (IHD) have been recently adopted to help give residential consumers more control over energy consumption, and to help meet environmental and security of supply objectives. The paper aims to identify the effectiveness of smart meters and real-time IHDs in reducing Shanghai household energy consumption through a pilot investigation. The research results demonstrate the improved awareness, understanding, and attitudes towards the energy saving by smart meters and IHDs.

  • 17502. Xu, Peng
    et al.
    Zhang, Xingxing
    Shen, Jingchun
    Yang, Tong
    Deng, Wu
    Tang, Llewellyn
    Empirical study of the energy saving potentials in Shanghai residential buildings through human behaviour change2015Conference paper (Refereed)
  • 17503. Xu, Peng
    et al.
    Zhang, Xingxing
    University of Nottingham, Ningbo.
    Shen, Jingchun
    University of Nottingham, Ningbo.
    Yang, Tong
    Deng, Wu
    Tang, Llewellyn
    Empirical study of the energy saving potentials in Shanghai residential buildings through human behaviour change2015Conference paper (Refereed)
  • 17504. Xu, Peng
    et al.
    Zhang, Xingxing
    Shen, Jingchun
    University of Nottingham, Ningbo.
    Yang, Tong
    Tang, Llewellyn
    Comparative study of a novel thermal absorber based solar photovoltaic/thermal against photovoltaic system2015Conference paper (Refereed)
  • 17505. Xu, Peng
    et al.
    Zhang, Xingxing
    Shen, Jingchun
    Yang, Tong
    Tang, Llewellyn
    Field-experimental study of a novel solar photovoltaic/thermal (PV/T) system2015Conference paper (Refereed)
  • 17506. Xu, Peng
    et al.
    Zhang, Xingxing
    University of Hull.
    Shen, Jingchun
    University of Hull.
    Zhao, Xudong
    He, Wei
    Li, Deying
    Parallel experimental study of a novel super-thin thermal absorber based photovoltaic/thermal (PV/T) system against conventional photovoltaic (PV) system2015In: Energy Reports, ISSN 2050-0505, E-ISSN 2352-4847, Vol. 1, p. 30-35Article in journal (Refereed)
    Abstract [en]

    Photovoltaic (PV) semiconductor degrades in performance due to temperature rise. A super thin-conductive thermal absorber is therefore developed to regulate the PV working temperature by retrofitting the existing PV panel into the photovoltaic/thermal (PV/T) panel. This article presented the parallel comparative investigation of the two different systems through both laboratory and field experiments. The laboratory evaluation consisted of one PV panel and one PV/T panel respectively while the overall field system involved 15 stand-alone PV panels and 15 retrofitted PV/T panels. The laboratory testing results demonstrated the PV/T panel could achieve the electrical efficiency of about 16.8% (relatively 5% improvement comparing with the stand-alone PV panel), and yield an extra amount of heat with thermal efficiency of nearly 65%. The field testing results indicated that the hybrid PV/T panel could enhance the electrical return of PV panels by nearly 3.5%, and increase the overall energy output by nearly 324.3%. Further opportunities and challenges were then discussed from aspects of different PV/T stakeholders to accelerate the development. It is expected that such technology could become a significant solution to yield more electricity, offset heating load freely and reduce carbon footprint in contemporary energy environment.

  • 17507.
    Xuyen Pettersson, Sofie
    Dalarna University, School of Technology and Business Studies, Economics.
    Determinants of visitor expenditures: The case of the Nordic World Ski Championships in Falun,Sweden in 20152017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This paper investigates the effect of the primary determinants of visitors’ total

    expenditure per trip and total daily expenditure at the event by using classic OLS

    regression model and Tobit regression model to individual micro data collected by a

    survey to participants at the The Nordic World Ski Championships in Falun, Sweden in

    2015. It is shown that country of origin and length of stay have effects on both total

    expenditure per trip and total daily expenditure at the event. While accommodation mode,

    transport mode to Falun, local kilometers travelled within Falun affect only total

    expenditure per trip. Visitors’ total daily expenditure at the event are also affected by age.

    Determinants such as income, sex, living in Falun, living at home while visiting the

    event, party size, companion age group, paid by others for accommodation, kilometers

    travelled by car to Falun, number of persons if travel by car, distance to Falun, previous

    visit to Falun and visiting family and friend have no effect on both total expenditure per

    trip and total daily expenditure at the event.

  • 17508.
    Yachin, Jonathan Moshe
    Dalarna University, School of Technology and Business Studies, Business Administration and Management.
    Baking Dalarna's biking cake: Collaboration as a means for destination competitiveness, a case study of “Biking Dalarna"2013Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the contemporary tourism industry, the competitive game is between destinations. Tourism operations struggle to remain competitive on the international market and their success depends to a large extent on other complementary and competing tourism organizations at the destination. It is the sum of the total tourism offerings at the destination which determines its attractiveness. This research explores tourism collaboration process as a means of generating destination competitiveness. The focus of the research is on the enhancing factors which contribute to the success of the collaboration and to the development of quality tourism products. The research studies the case of Biking Dalarna, a collaboration of different organizations at five biking destinations in Dalarna, Sweden. Its purpose is to develop biking tourism in the region and to make Dalarna into Sweden’s leading biking destination. It is a qualitative research; the empirical data was collected through in depth interviews with representatives of six Biking Dalarna member organizations. The qualitative data collected from the participants provides inside look into the members reflections and experience of collaborating. The findings of this research demonstrate how collaboration has improved the biking product in Dalarna and promoted solutions to development problems. The research finds the good relationship between the collaborating actors and the involvement and leadership of the regional tourism management organization as the most contributing factors to the success of Biking Dalarna. The research also suggests that a third desired outcome of collaboration, improved marketing attributes was yet to be achieved in the case of Biking Dalarna.

  • 17509.
    Yachin, Jonathan Moshe
    Dalarna University, School of Technology and Business Studies, Tourism Studies. Mid-Sweden University.
    The ‘customer journey’: Learning from customers in tourism experience encounters2018In: Tourism Management Perspectives, ISSN 2211-9736, E-ISSN 2211-9744, Vol. 28, p. 201-210Article in journal (Refereed)
    Abstract [en]

    For micro-tourism firms, customers are a readily-accessible and highly important knowledge source that often remains unutilised. This study explores firm–customer encounters along the customer journey as learning opportunities. Based on data collected through participant observations, interviews and a review of user-generated content, this case study provides an in-depth look into the customer journey, with a Swedish micro-tourism firm. The findings suggest that the possibility to generate knowledge about experiential purposes is conditioned by the firm's ability to bestow encounters with an experience-like quality and promote the customers' transformation into participants. This is facilitated by involving customers, adopting an experiential discourse and utilising in-situ supporting moments to socialise. Firms can also learn about customers' subjective perception of value from user-generated content. The study concludes that in the context of learning from customers, small size provides micro-tourism firms with an opportunity to engage in personal relationships with their customers.

  • 17510.
    Yachin, Jonathan Moshe
    et al.
    Dalarna University, School of Technology and Business Studies, Tourism Studies. Mittuniversitetet.
    Ioannides, Dimitri
    Mittuniversitetet.
    “Making do” in rural tourism: the resourcing behaviour of tourism micro-firms2020In: Journal of Sustainable Tourism, ISSN 0966-9582, E-ISSN 1747-7646Article in journal (Refereed)
    Abstract [en]

    We propose entrepreneurial bricolage as a framework that enables the description, explanation and exploration of the modus operandi of tour- ism micro-firms. Particularly, the notion of spatial bricolage constitutes fertile ground for further research and theoretical advances of sustain- able tourism entrepreneurship. The potential for rural tourism develop- ment is conditioned by entrepreneurs’ capability to utilise local physical and non-material resources sustainably. Thus, knowledge about the resourcing behaviour of micro-firms is paramount to understanding their role in promoting sustainable tourism. This study explores how rural micro-firms interact with their spatial environment to design tour- ism value propositions. Our analysis is based on interviews with eight- een owners-managers of tourism micro-firms in rural Sweden. We portray spatial bricolage as a resourcing behaviour that builds on the re-interpretation of existing resources, the unique features of the destin- ation and community involvement. The findings suggest that resource transfer facilitates sustainable development since it enables long-term planning and validates the entrepreneurs’ operation. Moreover, their small-scale enables rural tourism firms to utilise local resources in non- exploitative ways that minimise disturbance for other stakeholders.

  • 17511.
    Yachin, Jonathan Moshe
    Dalarna University, School of Technology and Business Studies, Tourism Studies. Mid Sweden University.
    The entrepreneur–opportunity nexus: discovering the forces that promote product innovations in rural micro-tourism firms2019In: Scandinavian Journal of Hospitality and Tourism, ISSN 1502-2250, E-ISSN 1502-2269, Vol. 19, no 1, p. 47-65Article in journal (Refereed)
    Abstract [en]

    The aim of this study is to investigate what sets in motion the process that results in product innovations in rural micro-tourism firms. The point of departure is to place entrepreneurship as a process that precedes innovations. This approach enables the application of the opportunity-based perspective, on the study of 40 new tourism products. Data were collected through in-depth interviews with owner-managers of micro-tourism firms in rural Sweden. The focus of the analysis is on the formation of the entrepreneur–opportunity nexus. The findings suggest that in forming the nexus, three types of forces are at play: internal, supply chain dynamics and reaction to changes. The notion of triggering forces adds a new dimension to the study of entrepreneurial opportunities. The theoretical contribution of this paper to tourism research is twofold. First, it points at the generating moment as a step towards theorising innovations, and second, the findings contribute to the growing knowledge base about entrepreneurial behaviour in micro-tourism firms in rural areas. Finally, in a practical manner, the findings of this study should encourage tourism entrepreneurs to invest in exploring the value chain, regard tourists as sources of knowledge and be attentive to changes in circumstances.

  • 17512.
    Yah, Fritz Alum
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering.
    Design/Evaluation of A Methodology For Performance Optimization Of Indexable Carbide Inserts2009Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    In this project, two broad facets in the design of a methodology for performance optimization of indexable carbide inserts were examined. They were physical destructive testing and software simulation. For the physical testing, statistical research techniques were used for the design of the methodology. A five step method which began with Problem definition, through System identification, Statistical model formation, Data collection and Statistical analyses and results was indepthly elaborated upon. Set-up and execution of an experiment with a compression machine together with roadblocks and possible solution to curb road blocks to quality data collection were examined. 2k factorial design was illustrated and recommended for process improvement. Instances of first-order and second-order response surface analyses were encountered. In the case of curvature, test for curvature significance with center point analysis was recommended. Process optimization with method of steepest ascent and central composite design or process robustness studies of response surface analyses were also recommended. For the simulation test, AdvantEdge program was identified as the most used software for tool development. Challenges to the efficient application of this software were identified and possible solutions proposed. In conclusion, software simulation and physical testing were recommended to meet the objective of the project.

  • 17513. Yan, Su-Rong
    et al.
    Zheng, Xiao-Lin
    Wang, Yan
    Song, William Wei
    Dalarna University, School of Technology and Business Studies, Information Systems.
    Zhang, Wen-Yu
    A graph-based comprehensive reputation model: exploiting the social context of opinions to enhance trust in social commerce2015In: Information Sciences, ISSN 0020-0255, E-ISSN 1872-6291, Vol. 318, p. 51-72Article in journal (Refereed)
    Abstract [en]

    Social commerce is a promising new paradigm of e-commerce. Given the open and dynamic nature of social media infrastructure, the governance structures of social commerce are usually realized through reputation mechanisms. However, the existing approaches to the prediction of trust in future interactions are based on personal observations and/or publicly shared information in social commerce application. As a result, the indications are unreliable and biased because of limited first-hand information and stake-holder manipulation for personal strategic interests. Methods that extract trust values from social links among users can improve the performance of reputation mechanisms. Nonetheless, these links may not always be available and are typically sparse in social commerce, especially for new users. Thus, this study proposes a new graph-based comprehensive reputation model to build trust by fully exploiting the social context of opinions based on the activities and relationship networks of opinion contributors. The proposed model incorporates the behavioral activities and social relationship reputations of users to combat the scarcity of first-hand information and identifies a set of critical trust factors to mitigate the subjectivity of opinions and the dynamics of behaviors. Furthermore, we enhance the model by developing a novel deception filtering approach to discard "bad-mouthing" opinions and by exploiting a personalized direct distrust (risk) metric to identify malicious providers. Experimental results show that the proposed reputation model can outperform other trust and reputation models in most cases. (C) 2014 Elsevier Inc. All rights reserved.

  • 17514.
    Yang, Bowen
    Dalarna University, School of Technology and Business Studies, Microdata Analysis.
    Ranking hotels for recommendation via generalized linear mixed model and Box-Cox model: A case of Stockholm rating data from booking.com2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis is aimed at recommending suitable hotels to the customers using the data collected from the website booking.com. In this thesis, data from Stockholm is chosen as an example, and statistical modeling is applied. We propose recommended hotels based on their rankings in terms of the scores of the hotels. The ranking score is derived by using eneralized linear mixed models. Box-Cox transformation is applied further to improve the previous analysis. Separate group analysis indicates that the ranks between different reviewer groups are significantly different. Model evaluation is executed via Cross-validation method by calculating the classification accuracies for all models. The best model is found based on theclassification accuracy, and we recommend the top 10, top 15 and top 20 hotels from the best model in this thesis.

  • 17515.
    Yang, Jinseok
    et al.
    Dalarna University, School of Technology and Business Studies, Business Administration and Management.
    Wittenberg, Philip
    Dalarna University, School of Technology and Business Studies, Business Administration and Management.
    Perceived Work-related Factors and Turnover Intention: - A Case Study of a South Korean Construction Company2016Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Purpose – Employee turnover entails considerable costs and is a major problem for the construction industry. By creating an extensive framework, this study aims to examine whether perceived work-related factors affect turnover intention in South Korean construction companies.

    Research design – The paper is based on the results of a questionnaire of 136 employees that was conducted and provided by a Korean construction company. Research hypotheses were tested via correlation analyses. The most influencing work-related factors, as well as differences among job levels, were determined by multiple regression analyses.

    Findings Communication, immediate leaders, organizational commitment, and organizational pride substantially affect turnover intentions. All of these factors can be considered as relational factors. The most influencing factors differ among job levels.

    Discussion/practical implications Immediate leaders should be aware of their role in retaining employees and enhance communication, organizational commitment and pride. This study shows how the importance of certain variables differs for groups of employees.

    Theoretical implications/limitationsThis study is based on a sample of employees from a Korean construction company. Therefore, the generalizability of the findings has to be tested. Future research should test the proposed framework with other factors or resources.

    Originality/value This study shed light on the turnover subject in the South Korean construction industry. It shows that different factors can influence turnover intention among job levels. A framework was created, which is based on 16 work-related factors including organizational factors, HRM practices and job attitudes.

  • 17516.
    Yang, Jinseok
    et al.
    Dalarna University, School of Technology and Business Studies, Business Administration and Management.
    Wittenberg, Philip
    Dalarna University, School of Technology and Business Studies, Business Administration and Management.
    Perceived Work-related Factors and Turnover Intention: A Case Study of a South Korean Construction Company2016Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Purpose – Employee turnover entails considerable costs and is a major problem for the construction industry. By creating an extensive framework, this study aims to examine whether perceived work-related factors affect turnover intention in South Korean construction companies.

    Research design – The paper is based on the results of a questionnaire of 136 employees that was conducted and provided by a Korean construction company. Research hypotheses were tested via correlation analyses. The most influencing work-related factors, as well as differences among job levels, were determined by multiple regression analyses.

    Findings Communication, immediate leaders, organizational commitment, and organizational pride substantially affect turnover intentions. All of these factors can be considered as relational factors. The most influencing factors differ among job levels.

    Discussion/practical implications Immediate leaders should be aware of their role in retaining employees and enhance communication, organizational commitment and pride. This study shows how the importance of certain variables differs for groups of employees.

    Theoretical implications/limitationsThis study is based on a sample of employees from a Korean construction company. Therefore, the generalizability of the findings has to be tested. Future research should test the proposed framework with other factors or resources.

    Originality/value This study shed light on the turnover subject in the South Korean construction industry. It shows that different factors can influence turnover intention among job levels. A framework was created, which is based on 16 work-related factors including organizational factors, HRM practices and job attitudes.

  • 17517.
    Yang, Tao
    et al.
    Dalarna University, School of Humanities and Media Studies, Chinese.
    Gao, Man
    Dalarna University, School of Humanities and Media Studies, Chinese.
    Teaching and learning Chinese in the virtual classroom: effective strategies and digital tools for teaching Chinese characters2019Conference paper (Refereed)
  • 17518.
    Yang, Tao
    et al.
    Dalarna University, School of Languages and Media Studies, Chinese.
    Hu, Lung-Lung
    Dalarna University, School of Languages and Media Studies, Chinese.
    Yan, Jia
    Dalarna University, School of Languages and Media Studies, Chinese.
    Gao, Man
    Dalarna University, School of Languages and Media Studies, Chinese.
    Teaching Chinese Writing System in Web-based Education2014In: NGL2014 Next Generation Learning Conference: Conference programme, Falun: Högskolan Dalarna, 2014, p. 22-22Conference paper (Refereed)
    Abstract [en]

    Teaching the Chinese ideographic writing system in web-based education has become the biggest challenge to the Chinese instructors, in terms of teaching technology and pedagogy. This paper presents the outcome of a research project that aims to overcome the technological obstacles and develop an optimized pedagogic method for teaching characters.

  • 17519. Yang-Wallentin, Fan
    Is There Any Interaction Effect Between Intention and Percieved Behavioral Control?2004In: MPR online, ISSN 1616-8119, E-ISSN 1432-8534, Vol. 8, no 2, p. 127-157Article in journal (Refereed)
  • 17520. Yang-Wallentin, Fan
    et al.
    Abramssom-Zetterberh,
    Durling,
    The impact of folate status and folic acid supplementation on the micronucleus frequency in human erythrocytes2005In: Mutation research, ISSN 0027-5107, E-ISSN 1873-135X, Vol. 603, no 1Article in journal (Refereed)
  • 17521. Yang-Wallentin, Fan
    et al.
    Catasús, Bino
    Ersson, Sofi
    Gröjer, Jan-Erik
    What gets measured gets…: On indicating, mobilizing and acting2007In: Accounting, Auditing & Accountability Journal, ISSN 1368-0668, E-ISSN 1758-4205, Vol. 20, no 4, p. 505 - 521Article in journal (Refereed)
    Abstract [en]

    Abstract: Purpose – The purpose of this paper is to empirically investigate the relationship underlying the often used adage “what gets measured gets managed”. Design/methodology/approach – The paper starts by reviewing the critique of the adage and then testing it by surveying 109 managers from 41 organizations. The paper includes the idea of mobilizing in the adage in order to highlight that there are other factors than indicating, which affect acting. In the positive test the paper uses the linear structural relations (LISREL) method to analyze the data. Findings – The paper finds that that the relationship between indicating and acting is not significant and that the introduction of mobilizing gives a better model fit. As a result the reformulation of the adage is: “What gets mobilized gets managed, especially if it gets measured”. Research limitations/implications – The paper shows that measuring is not per se a means to activate the organization. Rather, measurements support those issues that are already important in the organization. In practical terms, a reformulation could be: what gets talked about gets done, especially if there are numbers. Practical implications – The contribution of this paper is twofold. First, it finds no significant relationship between indicating and acting; and second, it introduces mobilizing to explain the relationship between indicating and acting. Originality/value – The paper scrutinizes the conventional wisdom encapsulated in the adage and by introducing mobilizing as an additional variable. The findings suggest that the adage needs to be reformulated.

  • 17522.
    Yari, Koresh
    Dalarna University, School of Humanities and Media Studies, History.
    Jag är kurd: En undersökning av kurders historiebruk kring Anfal-kampanjen och dess betydelse för sex kurdiska individer Författare:2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I denna studie undersöks kurders historiebruk kring Anfal-kampanjen och dess betydelse för sex kurdiska individer. De intervjuade består av ett mindre urval av kurder som lever i Sverige. För att besvara syftet har en kvalitativ forskningsansats tagits som utgått från Steinar, Brinkmann och Kvales kvalitativa forskningsintervju. Forskningsintervjun är halvstrukturerad.

    Studiens resultat har vidare analyserats utifrån teorierna om historiebruk. Teorin om historiebruk förklarar hur historien används för att bland annat fylla existentiella, vetenskapliga, moraliska och ideologiska syften. De olika topologierna användas som ett analysinstrument för att förstå hur kurderna, med samma bakgrunder, och olika mål och intressen, använder sig av historia. Samtidigt som de olika formerna av historiebruk kan användas för att precisera och analysera särskilda former av historiebruk kan de, då de brukas av individer, gå in i varandra och i enstaka fall utesluta varandra.

    Studiens resultat visar att de intervjuade främst använder den kurdiska historien för att fylla ett existentiellt syfte. På så sätt använder de historien för att orientera sig i nuet och att förstå sig själva. Resultatet visar även de intervjuade använder historien för att stärka sin identitet, inte glömma sina rötter, den förflutna händelsen av Anfal-kampanjen och skapa en känsla av stabilitet i den.

  • 17523.
    Yarmukhamedov, Sherzod
    Dalarna University, School of Technology and Business Studies, Economics.
    Trade effects of exchange rate fluctuations: Evidence from Sweden2007Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    An overview of the theoretical literature for the last two decades suggests that there is no clear-cut relationship one can pin down between exchange rate volatility and trade flows. Analytical results are based on specific assumptions and only hold in certain cases. Especially, the impact of exchange rate volatility on export and import activity investigated separately leads also to dissimilar conclusions among countries studied. The general presumption is that an increase in exchange rate volatility will have an adverse effect on trade flows and consequently, the overall heath of the world economy. However, neither theoretical models nor empirical studies provide us with a definitive answer, leaving obtained results highly ambiguous and inconsistent (Baum and Caglayan, 2006). We purposed to empirically investigate trade effects of exchange rate fluctuations in Sweden from the perspective of export and import in this research. The data comprises period from January 1993 to December 2006, where export and import volumes are considered from the point of their determinants, including exchange rate volatility, which has been measured through EGARCH model. The results for the case of Sweden show that short run dynamics of volatility negatively associated with both export and import, whereas considered from the case of previous period volatility it exhibits positive relationship. These results are consistent with the most findings of prior studies, where the relationship remained ambiguous.

  • 17524.
    Yaseen, Muhammad Usman
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Identification of cause of impairment in spiral drawings, using non-stationary feature extraction approach2012Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    Parkinson’s disease is a clinical syndrome manifesting with slowness and instability. As it is a progressive disease with varying symptoms, repeated assessments are necessary to determine the outcome of treatment changes in the patient. In the recent past, a computer-based method was developed to rate impairment in spiral drawings. The downside of this method is that it cannot separate the bradykinetic and dyskinetic spiral drawings. This work intends to construct the computer method which can overcome this weakness by using the Hilbert-Huang Transform (HHT) of tangential velocity. The work is done under supervised learning, so a target class is used which is acquired from a neurologist using a web interface. After reducing the dimension of HHT features by using PCA, classification is performed. C4.5 classifier is used to perform the classification. Results of the classification are close to random guessing which shows that the computer method is unsuccessful in assessing the cause of drawing impairment in spirals when evaluated against human ratings. One promising reason is that there is no difference between the two classes of spiral drawings. Displaying patients self ratings along with the spirals in the web application is another possible reason for this, as the neurologist may have relied too much on this in his own ratings.

  • 17525. Yazdanshenas, Eshagh
    et al.
    Furbo, Simon
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Theoretical comparison between solar combisystems based on bikini tanks and tank-in-tank solar combisystems2008In: Eurosun 2008, Lisbon, 2008Conference paper (Other academic)
    Abstract [en]

    Theoretical investigations have shown that solar combisystems based on bikini tanks for low energy houses perform better than solar domestic hot water systems based on mantle tanks. Tank-in-tank solar combisystems are also attractive from a thermal performance point of view. In this paper, theoretical comparisons between solar combisystems based on bikini tanks and tank-in-tank solar combisystems are presented. The investigations are carried out for different designs and sizes of the two solar heating system types installed in different houses. The investigations show which types of solar combisystems are suitable for low energy houses, new houses built according to the building codes and old houses.

  • 17526.
    Ybrahim, Rawan
    Dalarna University, School of Technology and Business Studies, Human Resource Management.
    Kränkande särbehandling i arbetslivet: En kvalitativ intervjustudie om hur kränkande särbehandling uppstår i organisationer med utredningsfokus2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this study is to investigate why victimization occurs in organizations and to create an understanding for how working groups perceive faktaundersökning (a Norwegian investigation method for victimization). The method used is a qualitative interview study in which three investigators and three clients of the investigation method faktaundersökning were individually interviewed. Three reports from the investigations has also been analysed and later used in the result. Four different cases in three different organizations has been investigated for this study in total. The study shows that all organizations had an insufficient working environment with multiple factors that were the underlying cause of the emerge of victimization, bullying and conflicts. These factors were later able to be categorized as; communication, leadership and roles, organizational structure and culture, policies, understanding and values. The study thus showed that the individuals who performed the negative interpersonal actions were the result of an insufficient organizational and social work environment. Furthermore, the study showed that the respondents experienced the faktaundersökning as dry, direct and hard to go through for both the different parties, but also the working groups and the organizations. The study showed that it is important that all parties are offered emotional support as soon as possible in order for the parties to feel fairly treated and thus become more willing to cooperate in the investigations. According to the respondents, trust and impartiality between investigators and the parties were an important aspect for the investigation to generate in such a true result as possible, where the right of reply plays a crucial role in the legal certainty of the investigation.

  • 17527.
    ye, yanfang
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    defining a unified scale for a test battery for Parkinson Patients2010Independent thesis Basic level (degree of Bachelor)Student thesis
  • 17528.
    Yella, Siril
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    A.I. Techniques for the Automating Railway Sleeper Inspections2006Licentiate thesis, monograph (Other academic)
  • 17529.
    Yella, Siril
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Expert system for predicting slipperiness on winter roads in the province of Dalarna, Sweden2003Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    Friction plays a key role in causing slipperiness as a low coefficient of friction on the road may result in slippery and hazardous conditions. Analyzing the strong relation between friction and accident risk on winter roads is a difficult task. Many weather forecasting organizations use a variety of standard and bespoke methods to predict the coefficient of friction on roads. This article proposes an approach to predict the extent of slipperiness by building and testing an expert system. It estimates the coefficient of friction on winter roads in the province of Dalarna, Sweden using the prevailing weather conditions as a basis. Weather data from the Road Weather Information System, Sweden (RWIS) was used. The focus of the project was to use the expert system as a part of a major project in VITSA, within the domain of Intelligent Transport Systems.

  • 17530.
    Yella, Siril
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Pattern recognition approach for the automatic classification of data from impact acoustics2006In: IASTED International Conference on Artificial Intelligence and Soft Computing, Palma de Mallorca, 2006Conference paper (Other academic)
    Abstract [en]

    This paper addresses and deals with the problem of automating condition monitoring of wood in the transportation domain. Current day condition monitoring applications involving wood are mostly carried out through visual inspection and if necessary some impact acoustic examination is carried out. These inspections are mostly done intuitively by skilled personnel. Hence, it is desired to automate such intuitive human skills for the development of more robust and reliable testing methods. Data resulting from impact acoustics tests made on wooden beams has been used. The relation between condition of the wooden beam and their respective emissions has been analyzed experimentally applying different feature extraction techniques. Combining the usage of traditional frequency extraction techniques like the magnitude of the signal together with famous speech recognition techniques like Cepstral Coefficients, Linear Predictive Coding yield good results. Effect of using classifiers like Gaussian Mixture Models and Learning Vector Quantization has been tested and compared. In the current case Gaussian mixture model seem to achieve higher classification rates than Learning Vector Quantization model.

  • 17531.
    Yella, Siril
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Pattern recognition for automating condition monitoring of wooden railway sleepers2008Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The thesis aims to investigate the current state of railway sleeper inspection and proposes automatic testing procedures based on pattern recognition for future inspections concerning the condition of the sleeper. Wooden railway sleeper inspections in Sweden are currently done by hand. That is to say, a human inspector in charge of the maintenance activities visually examines each structure in turn for the presence of cracks on the sleeper. Where necessary some deeper inspection may be carried out on site, for example using an axe to hit and judge the condition of the sleeper by listening to the sound produced. Though the manual procedure uses non-destructive testing methods (visual and sound analysis), decision making is largely based on intuition; moreover the process is rather slow, expensive and also requires skilled and trained staff. Maintaining an even quality standard is another serious issue. In order to be able to fulfil the aims of the thesis, emphasis on the likely factors concerning sleeper condition was a key issue. Studies based on emulation of the human inspection process have been considered a promising route of enquiry. The emulation process is achieved by selecting and evaluating two non-destructive testing methods. The first method (impact acoustic analysis) aims to build an automatic procedure to replace the usage of an axe for distinguishing sounds; which can be described qualitatively as a crisp sound in case of a good sleeper and a dull thud on their bad counterparts. The second method (vision analysis) is to develop an appropriate machine vision algorithm to replicate the visual examination. Data were collected for each of the above methods and appropriate features were extracted. Frequency based features and crack based features have been extracted in the case of impact acoustics and machine vision methods respectively. Pattern recognition has been mainly researched for further classification work concerning the condition (good or bad) of the sleeper. Research conducted on the usage of the inspection methods such as impact acoustic and machine vision analysis show that the methods can form the basis of an automatic sleeper condition monitoring procedure. Further, two more non-destructive testing methods namely electrical resistivity analysis and ultrasound analysis have also been tested. Usage of such methods did not yield success in the current case, but they have contributed in adding knowledge to the domain in cases of relevant problems. Initially, work has pursued data from only one inspection method at a time. Given that data from a single method (or sensor) seems not to be adequate to make a reliable judgement; data fusion was investigated with an aim of achieving more reliable and robust results. Data fusion has been investigated at three different levels namely sensor-level fusion, feature-level fusion and classifier-level fusion. Results achieved by fusion in the current thesis demonstrate an overall efficiency of around 90% when compared to a human operator. This can be regarded as a good result, given that even humans disagree on certain judgements; and destructive testing can be seen as the only way to resolve such disagreements.

  • 17532.
    Yella, Siril
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Baskar, Jayalakshmi
    Dougherty, Mark
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Machine vision for analysing the position of fastening nails on wooden railway sleepers2011In: Signal and Image Processing, 2011 / [ed] Rao, K.R., Dallas, Texas, USA, 2011Conference paper (Refereed)
    Abstract [en]

    Wooden railway sleeper inspections in Sweden and to a large extent elsewhere are carried out manually by a human operator; visual inspection being the most common approach. Manually inspecting railway sleepers is slow and time consuming. Machine vision algorithms investigating surface cracks on the sleeper and sinking of the metal plate have been studied for the purpose of automating the task. In this particular article, information concerning how far the fastening nail has lifted out of position is investigated with an aim of using such information while assessing the condition of the sleeper. Laser beams incident on the sleeper have been used to highlight the geometrical form of the sleeper/plate/nail complex. Digital images of the nail were acquired mimic human visual capabilities. Appropriate image analysis techniques were applied to further process the images and necessary features were extracted. Results of unsupervised learning, achieved in the current work indicate that expectation maximization algorithm produced reliable results.

  • 17533.
    Yella, Siril
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Dougherty, Mark
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Automatically detecting the number of logs on a timber truck2013In: Journal of Intelligent Systems, ISSN 2191-026X, Vol. 22, no 4, p. 417-435Article in journal (Refereed)
    Abstract [en]

    This article describes a method of automatically detecting, counting and classifying logs on a timber truck using a photograph (taken by the driver). An image-processing algorithm is developed to process the photograph to calculate an estimate of the number of logs present and their respective diameters. The algorithm uses color information in multiple color spaces as well as geometrical operators to segment the image and extract the relevant information. This information enables the sawmill to better plan internal logistics and production in advance of the truck’s arrival time. The algorithm is robust with respect to external factors such as varying lighting conditions and camera angle, but some inaccuracies remain, mainly caused by logs being occluded or covered in mud or snow.

  • 17534.
    Yella, Siril
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Dougherty, Mark
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Philosophical challenges concerning education and career orientation in the ITS area2005In: 10th Euro Working Group in Transportation, Poznan, Poland: Proc 10th Euro Working Group in Transportation , 2005Conference paper (Other academic)
  • 17535.
    Yella, Siril
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Dougherty, Mark
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Gupta, N K
    Artificial Intelligence techniques for the automatic interpretation of data from non-destructive testing2006In: Insight (Northampton), ISSN 1354-2575, E-ISSN 1754-4904, Vol. 48, no 1, p. 10-20Article in journal (Other academic)
    Abstract [en]

    This paper attempts to summarise the findings of a large number of research papers deploying artificial intelligence (AI) techniques for the automatic interpretation of data from non-destructive testing (NDT). Problems in the rail transport domain are mainly discussed. However, a majority of the emphasis in this paper is laid on rail inspection problems, since it was believed that the review would provide a perfect ground to the authors in pursuing further work within the rail inspection area. NDT is a broad name for a variety of methods and procedures concerned with all aspects of uniformity, quality and serviceability of materials and structures, without causing damage to the material that is being inspected. During the past several years, problems concerning the automatic interpretation of data from NDT have received good attention and have stimulated interests in other areas like transportation, for making key assessments within some of its subject areas. Rail, air and marine industries together with bridge inspection and pavement maintenance are good examples of such areas where a considerable amount of work has been done. Such work neatly splits into two schools. The first school investigates the classical usage of data by an experienced human operator to determine the condition of the inspected material or structure. The other school focuses attention on the automatic interpretation of NDT data using AI techniques, in determining the result of inspection. The scope of this paper is only limited to the automatic interpretation of data from NDT, with the goal of assessing embedded flaws as quickly and accurately as possible in a cost effective fashion. AI techniques such as neural networks, machine vision, knowledge-based systems and fuzzy logic were applied to a wide spectrum of problems in the area. A secondary goal was to provide an insight into possible research methods concerning railway sleeper inspection by automatic interpretation of data. A brief introduction is provided for the benefit of the readers unfamiliar with the techniques.

  • 17536.
    Yella, Siril
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Dougherty, Mark
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Gupta, Narendra
    Fuzzy logic approach for automating visual condition monitoring of railway sleepers2007In: IICAI, Indian International Conference on Artificial Intelligence, Pune, India, 2007Conference paper (Other academic)
  • 17537.
    Yella, Siril
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Dougherty, Mark
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Gupta, Narendra K.
    Condition monitoring of wooden railway sleepers2009In: Transportation Research Part C: Emerging Technologies, ISSN 0968-090X, E-ISSN 1879-2359, Vol. 17, no 1, p. 38-55Article in journal (Refereed)
    Abstract [en]

    Wooden railway sleeper inspections in Sweden are currently performed manually by a human operator; such inspections are to large extent based on visual analysis. In this paper a machine vision based approach has been considered to emulate the visual abilities of the human operator to enable automation of the process. Digital images from either ends (left and right) of the sleepers have been acquired. A pattern recognition approach has been adopted to classify the condition of the sleeper into classes (good or bad) and thereby achieve automation. Appropriate image analysis techniques were applied and relevant features such as the number of cracks on a sleeper, average length and width of the crack and the condition of the metal plate were determined. Feature fusion has been proposed in order to integrate the features obtained from each end for the classification task which follows. The effect of using classifiers like multi-layer perceptron and support vector machines has been tested and compared. Results obtained from the experiments show that multi-layer perceptron and support vector machines have achieved encouraging results, with a classification accuracy of 90%; thereby exhibiting a competitive performance when compared to a human operator.

  • 17538.
    Yella, Siril
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Dougherty, Mark
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Gupta, Narendra K.
    Data fusion for automating condition monitoring of wooden railway sleepers2008In: Insight (Northampton), ISSN 1354-2575, E-ISSN 1754-4904, Vol. 50, no 7, p. 356-363Article in journal (Other academic)
    Abstract [en]

    Wooden railway sleeper inspections in Sweden are currently done by hand. That is to say, a human inspector in charge of the maintenance activities visually examines each structure in turn for the presence of cracks on the sleeper. Where necessary some deeper inspection may be carried out on site, for example using an axe to hit and judge the condition of the sleeper by listening to the sound produced. Though the manual procedure uses non-destructive testing methods (visual and sound analysis), decision-making is largely based on intuition; moreover the process is rather slow, expensive and also requires skilled and trained staff. Maintaining an even quality standard is another serious issue. Hence, it is desired to automate the human inspection process by proposing automatic testing procedures for future inspections concerning the condition of the sleeper. Studies based on emulation of the human inspection process have been considered a promising route of enquiry for automation. Such an emulation process is achieved by selecting and evaluating two non-destructive inspection methods. The first method (impact acoustic analysis) aims to build an automatic system to replace the usage of an axe for distinguishing sounds. The second method (visual analysis) is to develop an appropriate machine vision algorithm to replicate the visual examination. Further, the above-mentioned methods were fused (data fusion) to generate a single output condition concerning the condition of the sleeper. In the current work, fusion has been achieved in mainly three levels, namely sensor-level, feature-level and classifier-level. Experimental results achieved in this work indicate that data fusion has achieved superior performance when compared with using data from one method at a time.

  • 17539.
    Yella, Siril
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Ghiamati, Samira
    Dougherty, Mark
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Condition monitoring of wooden railway sleepers using time-frequency techniques and pattern classification2009In: Systems, Man and Cybernetics, 2009. SMC 2009. IEEE International Conference on Systems, San Antonio, Texas, USA, 2009, p. 4164-4169Conference paper (Refereed)
    Abstract [en]

    Railway sleepers are a key engineering element of all railways. Lack of much sophistication in monitoring railway sleepers makes it a key problem within the rail transportation domain. Current day condition monitoring applications involving wooden railway sleepers are mostly carried out through visual inspection and if necessary some impact acoustic examination is carried out. Decision making is largely based on intuition; moreover the process of manually inspecting sleepers is rather slow and expensive. Maintaining an even quality standard is another serious issue. In this article, a pattern recognition and classification approach is taken to automate such intuitive human skills for the development of more robust and reliable testing methods. Features were extracted from the impact acoustic emissions of wooden sleepers and were used for pattern classification. Time-frequency based feature extraction techniques such short-time Fourier transform and discrete wavelet transform yielded good results. Multi-layer perceptron, radial basis function neural networks and support vector machine classifiers have been tested and compared. Further classifier fusion was investigated by considering the output of single best classifiers as input to a new classifier with an aim of improving performance. Results obtained experimentally demonstrate a classification accuracy of around 84%.

  • 17540.
    Yella, Siril
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Gupta, Naredra K.
    Dougherty, Mark
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Automating condition monitoring of wooden railway sleepers2007In: EngineerIT, ISSN 1991-5047, Vol. 2, no 10Article in journal (Other academic)
  • 17541.
    Yella, Siril
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Gupta, Naren
    Dougherty, Mark
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Condition monitoring using pattern recognition techniques on data from acoustic emissions2006In: ICMLA 2006: 4th International Conference on Machine Learning and Applications, Proceedings, 2006Conference paper (Other academic)
    Abstract [en]

    Condition monitoring applications deploying the usage of impact acoustic techniques are mostly done intuitively by skilled personnel. In this article, a pattern recognition approach is taken to automate such intuitive human skills for the development of more robust and reliable testing methods. The focus of this work is to use the approach as a part of a major research project in the rail inspection area, within the domain of Intelligent Transport Systems. Data from impact acoustic tests made on wooden beams have been used. The relation between condition of the wooden beams and respective sounds they make when struck, has been analyzed experimentally. Features were extracted from the acoustic emissions of wooden beams and were used for pattern classification. Features such as magnitude of the signal, natural logarithm of the magnitude and Mel-frequency cepstral coefficients, yielded good results. The extracted feature vectors were used as input to various pattern classifiers for further pattern recognition task. The effect of using classifiers like Support vector machines and Multi-layer perceptron has been tested and compared. Results obtained experimentally, demonstrate that Support vector machines provide good detection rates for the classification of impact acoustic signals in the NDT domain.

  • 17542.
    Yella, Siril
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Gupta, Narendra
    Dougherty, Mark
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Comparison of pattern recognition techniques for the classification of impact acoustic emissions2007In: Transportation Research Part C: Emerging Technologies, ISSN 0968-090X, E-ISSN 1879-2359, Vol. 15, no 6, p. 345-360Article in journal (Refereed)
    Abstract [en]

    Current day condition monitoring applications involving wood are mostly carried out through visual inspection and if necessary some impact acoustic examination is carried out. These inspections are mainly done intuitively by skilled personnel. In this paper, a pattern recognition approach has been considered to automate such intuitive human skills for the development of robust and reliable methods within the area. The study presents a comparison of several pattern recognition techniques combined with various stationary feature extraction techniques for classification of impact acoustic emissions. Further issues concerning feature fusion are discussed as well. It is hoped that this kind of broad analysis could be used to handle a wide spectrum of tasks within the area, and would provide a perfect ground for future research directions. A brief introduction to the techniques is provided for the benefit of the readers unfamiliar with the techniques. Pattern classifiers such as support vector machines, etc. are combined with stationary feature extraction techniques such as linear predictive cepstral coefficients, etc. Results from support vector machines in combination with linear predictive cepstral coefficients delivered good classification rates. However, Gaussian mixture models delivered higher classification rates when feature fusion is proposed.

  • 17543.
    Yella, Siril
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Nyberg, Roger G.
    Dalarna University, School of Technology and Business Studies, Information Systems.
    Assessing the quality and reliability of visual estimates in determining plant cover on railway embankments2016In: Web Information Systems Engineering – WISE 2016: 17th International Conference, Shanghai, China, November 8-10, 2016, Proceedings, Part II / [ed] Wojciech Cellary, Mohamed F. Mokbel, Jianmin Wang, Hua Wang, Rui Zhou, Yanchun Zhang, 2016, Vol. 10042, p. 404-410Conference paper (Refereed)
    Abstract [en]

    This study has investigated the quality and reliability of manual assessments on railway embankments within the domain of railway maintenance. Manually inspecting vegetation on railway embankments is slow and time consuming. Maintenance personnel also require extensive knowledge of the plant species, ecology and bio-diversity to be able to recommend appropriate maintenance action. The overall objective of the study is to investigate the reliable nature of manual inspection routines in favour an automatic approach. Visual estimates of plant cover reported by domain experts’ have been studied on two separate railway sections in Sweden. The first study investigated visual estimates using aerial foliar cover (AFC) and sub-plot frequency (SF) methods to assess the plant cover on a railway section in Oxberg, Alvdalsbanan, Sweden. The second study investigated visual estimates using aerial canopy cover method on a railway section outside Vetlanda, Sweden. Visual estimates of the domain experts were recorded and analysis-of-variance (ANOVA) tests on the mean estimates were investigated to see whether if there were disagreements between the raters’. ICC(2, 1) was used to study the differences between the estimates. Results achieved in this work indicate statistically significant differences in the mean estimates of cover (p < 0.05) reported by the domain experts on both the occasions.

  • 17544.
    Yella, Siril
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Nyberg, Roger G
    Dalarna University, School of Technology and Business Studies, Information Systems.
    Gupta, Narendra K.
    Edinburgh Napier University.
    Dougherty, Mark
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Reliability of manual assessments in determining the types of vegetation on railway tracks2015In: Web Information Systems Engineering – WISE 2015: 16th International Conference, Miami, FL, USA, November 1-3, 2015, Proceedings, Part II / [ed] Wang, J., Cellary, W., Wang, D., Wang, H., Chen, S.-C., Li, T., Zhang, Y., Springer, 2015, Vol. 9149, p. 391-399Conference paper (Refereed)
    Abstract [en]

    Current day vegetation assessments within railway maintenance are (to a large extent) carried out manually. This study has investigated the reliability of such manual assessments by taking three non-domain experts into account. Thirty-five track images under different conditions were acquired for the purpose. For each image, the raters’ were asked to estimate the cover of woody plants, herbs and grass separately (in %) using methods such as aerial canopy cover, aerial foliar cover and sub-plot frequency. Visual estimates of raters’ were recorded and analysis-of-variance tests on the mean cover estimates were investigated to see whether if there were disagreements between the raters’.  In tra-correl ation coefficient was used to study the differences between the estimates. Results achieved in this work revealed that seven out of the nine analysis-of-variance tests conducted in this study have demonstrated significant difference in the mean estimates of cover (p < 0.05).

  • 17545.
    Yella, Siril
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Nyberg, Roger G.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Payvar, Barsam
    Dougherty, Mark
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Gupta, Narendra
    Edinburgh Napier University.
    Machine vision approach for automating vegetation detection on railway tracks2013In: Journal of Intelligent Systems, ISSN 2191-026X, Vol. 22, no 2, p. 179-196Article in journal (Refereed)
    Abstract [en]

    The presence of vegetation on railway tracks (amongst other issues) threatens track safety and longevity. However, vegetation inspections in Sweden (and elsewhere in the world) are currently being carried out manually. Manually inspecting vegetation is very slow and time consuming. Maintaining an even quality standard is also very difficult. A machine vision-based approach is therefore proposed to emulate the visual abilities of the human inspector. Work aimed at detecting vegetation on railway tracks has been split into two main phases. The first phase is aimed at detecting vegetation on the tracks using appropriate image analysis techniques. The second phase is aimed at detecting the rails in the image to determine the cover of vegetation that is present between the rails as opposed to vegetation present outside the rails. Results achieved in the current work indicate that the machine vision approach has performed reasonably well in detecting the presence/absence of vegetation on railway tracks when compared with a human operator.

  • 17546.
    Yella, Siril
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Pasha, Sajjad M.
    Dougherty, Mark
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Gupta, Narendra K.
    Classifier fusion for condition monitoring of wooden railway sleepers2008In: Engineer IT, ISSN 1991-5047, p. 31-35Article in journal (Other academic)
  • 17547.
    Yella, Siril
    et al.
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Shaik, Asif ur Rahman
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Dougherty, Mark
    Dalarna University, School of Technology and Business Studies, Computer Engineering.
    Pattern recognition for classifying the condition of wooden railway sleepers2010In: Multimedia Computing and Information Technology (MCIT), 2010 International Conference on Multimedia Computing and Information Technology, Sharjah, 2010, p. 61-64Conference paper (Refereed)
    Abstract [en]

    This paper summarises the results of using a pattern recognition approach for classifying the condition of wooden railway sleepers. Railway sleeper inspections are currently done manually; visual inspection being the most common approach, with some deeper examination using an axe to judge the condition. Digital images of the sleepers were acquired to compensate for the human visual capabilities. Appropriate image analysis techniques were applied to further process the images and necessary features such as number of cracks, crack length etc have been extracted. Finally a pattern recognition and classification approach has been adopted to further classify the condition of the sleeper into classes (good or bad). A Support Vector Machine (SVM) using a Gaussian kernel has achieved good classification rate (86%) in the current case.

  • 17548.
    Yeneneh, Getu Temasgen
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Testing of Apis System Platform in Grid-Connected Photovoltaic System and Comparison with Metrum for Fault Detection and Diagnosis2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A real time data management web-based software-platform for PV plant monitoring called Apis was tested for fault detection and diagnosis of large scale grid-connected photovoltaic systems. This method was compared with Metrum system which is also another web based monitoring system used in grid connected PV systems. The objective of testing and comparisons were to observe the Apis system performance in large scale PV systems particularly for fault detection, and to identify which of the two systems could give more information to easily identify type of fault and point out the fault location in PV plants.

    The experiment were carried out in the selected two different arrays that have a capacity of 18.4kW and 17.6 kW with four string inverters each, to test three cases at Glava energy center solar park, Sweden. The first demonstrates the response of the systems when the wiring loose or cable disconnection fault occurs in the plant. The second demonstrates the output of the inverters when partial shading is gradually increased and the third demonstrates the output when the fault at components (i.e. at inverter, fuse and circuit breaker) is applied. Both systems collect data from inverters. However, in Apis system, data from individual inverters of the plant could be collected separately in both AC and DC sides while Metrum system was measuring the total output of the whole inverters in the plant.

    During the string disconnection, the Apis monitoring system showed a power drop to zero from the defected strings making it possible to identify them. In the same way during the inverters’ fault the power output of the failed inverter was dropped to zero. However, the normal strings and inverters were still working properly. Meanwhile the Metrum system only displayed a reduced power output which doesn’t directly identify the problem and requires manual inspection. In the case of partial shading there was a persistent difference occurred between the defected string and normal one but it did not dropped to zero at all.

    Apis system is able to differentiate and locate the faults by comparing input and output results of different inverters within the plant, unlike Metrum system which measures the total output of the plant. Nevertheless, Apis system still has less possibility to determine the type of fault further than estimation.

  • 17549.
    Yildiz, Pinar
    Dalarna University, School of Health and Social Studies, Sociology.
    Feminist nationalists: A Gender Perspective in Nationalism and Warfare2011Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    Using a method of qualitative interviewing I have studied women?s place in two nationalist movements from without a gender perspective. My main objective has been to scrutinize the relationship between nationalism and feminism as well as investigate the interaction between men and women in the context of war and war-training. In addition to this, I have sought to review the various ways in which the women have attempted to change the gender system and analyzed the outcome of these attempts. I argue that the will and ability to change the gender system partly comes from the original reason for the women in question to connect with the nationalist movement and partly from their ability to organize the female group and form a common agenda. Consequently, the woman who originated from a mutual background with her fellow female fighters showed a stronger ability of implementing changes in the gender system and improving the situation for the female fighters. On the other hand, the woman who was in a context where each female came from different places experienced difficulties doing the same thing. Furthermore, it is evident that the woman whose female group succeeded in changing the gender system had been involved in a non-party woman?s foundation with feminist aims, thus being aware of the feminist cause, which is in contrast to the other female group, which contained women who were uneducated and analphabetic.

  • 17550.
    Yildiz, Pinar
    et al.
    Dalarna University, School of Health and Social Studies, Sociology.
    Aslan, Farida
    Dalarna University, School of Health and Social Studies, Sociology.
    Emotioner i företaget WeSC:s marknadsföring: Tillämpningen av en subkulturs livsstil i varumärket2009Independent thesis Basic level (degree of Bachelor)Student thesis
    Abstract [sv]

    Denna uppsats undersöker den emotionella dimensionen i det kommersiella företaget WeSC:s marknadsföring genom att göra en kvalitativ innehållsanalys på datamaterialet som har bestått av en av deras senaste reklamfilmer, sekundära intervjuer som gjorts med grundaren Greger Hagelin, företagets presentation i boken Superbrands Sverige (2004) samt på hemsidan. Vi har även kompletterat analysen genom att göra en sekundär analys på forskaren Rebecca Beals studier av den subkultur som WeSC använder sig utav i sin emotionellt säljande marknadsföring. Den analys som vi gjorde av Beals studier resulterade i att vi kunde utröna tre viktiga grundstenar för skateboardkulturen – 1. Öppet deltagandet, att alla skulle få möjligheten att vara med oavsett bakgrund, 2. Individuell ansvarsfullhet, att varje utövare skulle ansvara för sitt eget spel i frånvaron av domare, regler och tränare, samt 3. Möjligheten att vara kreativ, frånvaron av domare, regler och tränare skulle tillförsäkra vare utövare att vederbörande var sin egen expert och därigenom kunde använda sin egen kreativitet till att skapa sitt eget spel. När vi sedan jämförde innehållet i dessa grundstenar med WeSC:s presentation av samma grundstenar i sin marknadsföring upptäckte vi att mycket av det ursprungliga innehållet modifierats i syfte att anpassa företagets kommersiella ansats. Detta tolkar vi som ett explicit exempel på att anammandet av subkultur av ett företag inte alltid fungerar positivt för subkulturen – då dess huvudsakliga symboliska värden förgås i kommersialiseringens och marknadsföringens process.

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