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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

Trust Building for Online Private Sellers : Case of Taobao in China

Xu, Miaowen, Guo, Xinlei January 2016 (has links)
Aim:The aim of our study is to analyzeelements of online trust building process from sellers’ standpoint based on case study of Chinese website: Taobao. Method:This study was conducted in qualitative method with 12 interviewees as online sellers from Taobao website. Data presentation involves tables and figures to help readers to understand trust building process and apply it in business. Result & Conclusions: Online trust building is dynamic and interactive. Three main elements of trust building are product, communication and 3rd party. Trust building process goes through three stages: knowledge-based trust, experience-based trust, and relationship-based trust. Suggestions for future research: Limitation of generality suggests further study in quantitative method. Since it is a single case study specific in China, comparison cross-culture or between websites is also suggested as future possibilitiesto test generalizability of this theoretic framework. Contribution & implication: This study provided atheoretic framework for online trust building process in real-world context. Management implication was suggested to focus on development of product, communication and 3rdparty service for sellers and website holder
112

Context-aware GPS integrity monitoring for Intelligent Transport Systems (ITS)

Binjammaz, Tareq January 2015 (has links)
The integrity of positioning systems has become an increasingly important requirement for location-based Intelligent Transports Systems (ITS). The navigation systems, such as Global Positioning System (GPS), used in ITS cannot provide the high quality positioning information required by most services, due to the various type of errors from GPS sensor, such as signal outage, and atmospheric effects, all of which are difficult to measure, or from the map matching process. Consequently, an error in the positioning information or map matching process may lead to inaccurate determination of a vehicle’s location. Thus, the integrity is require when measuring both vehicle’s positioning and other related information such as speed, to locate the vehicle in the correct road segment, and avoid errors. The integrity algorithm for the navigation system should include a guarantee that the systems do not produce misleading or faulty information; as this may lead to a significant error arising in the ITS services. Hence, to achieve the integrity requirement a navigation system should have a robust mechanism, to notify the user of any potential errors in the navigation information. The main aim of this research is to develop a robust and reliable mechanism to support the positioning requirement of ITS services. This can be achieved by developing a high integrity GPS monitoring algorithm with the consideration of speed, based on the concept of context-awareness which can be applied with real time ITS services to adapt changes in the integrity status of the navigation system. Context-aware architecture is designed to collect contextual information about the vehicle, including location, speed and heading, reasoning about its integrity and reactions based on the information acquired. In this research, three phases of integrity checks are developed. These are, (i) positioning integrity, (ii) speed integrity, and (iii) map matching integrity. Each phase uses different techniques to examine the consistency of the GPS information. A receiver autonomous integrity monitoring (RAIM) algorithm is used to measure the quality of the GPS positioning data. GPS Doppler information is used to check the integrity of vehicle’s speed, adding a new layer of integrity and improving the performance of the map matching process. The final phase in the integrity algorithm is intended to verify the integrity of the map matching process. In this phase, fuzzy logic is also used to measure the integrity level, which guarantees the validity and integrity of the map matching results. This algorithm is implemented successfully, examined using real field data. In addition, a true reference vehicle is used to determine the reliability and validity of the output. The results show that the new integrity algorithm has the capability to support a various types of location-based ITS services.
113

Characterising failure of structural materials using digital images

Conradie, Johannes Hendrik 03 1900 (has links)
Thesis (MEng)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: The fracture of ductile materials is currently regarded as a complex and challenging phenomenon to characterise and predict. Recently, a bond-based, non-local theory was formulated called the peridynamic theory, which is able to directly solve solid mechanics problems that include fracture. The failure criterion is governed by a critical stretch relation between bonds. It was found in literature that the critical stretch relates to the popular fracture mechanics parameter called the critical energy release rate for predicting brittle linear-elastic failure. It was also proposed that the non-linear critical energy release rate or J-integral can be used to model ductile failure using peridynamics. The aim of this thesis was to investigate the validity of using the J-integral to determine the critical stretch for predicting ductile failure. Standard ASTM fracture mechanics tests on Compact Tension specimens of Polymethyl methacrylate, stainless steel 304L and aluminium 1200H4 were performed to determine the critical energy release rates and non-linear Resistance-curves. Furthermore, a novel peridynamic-based algorithm was developed that implements a critical energy release rate based failure criterion and Digital Image Correlation (DIC) measured full surface displacement fields of cracked materials. The algorithm is capable of estimating and mapping both the peridynamic damage caused by brittle cracking and damage caused by plastic deformation. This approach was used to validate the use of an energy release rate based failure criterion for predicting linear-elastic brittle failure using peridynamics. Also, it showed a good correlation among the test results for detecting plastic damage in the alloys when incorporating the respective J-integral derived critical stretch values. Additionally, Modified Arcan tests were performed to obtain Mode I, Mode II and mixed Mode fracture load results of brittle materials. Mode I peridynamic models compared closely to test results when using the Mode I critical energy release rate, derived critical stretch and served as validation for the approach. Moreover, it was argued that Mode I failure criteria cannot in principle be used to model shear failure. Therefore, it was proposed to rather use the appropriate Mode II and mixed Mode critical energy release rates to predict the respective failures in peridynamics. Also, for predicting ductile failure loads it was found that using a threshold energy release rate derived from the R-curve yielded considerably more accurate failure load results compared to the usage of the critical energy release rate, i.e. J-integral. In this thesis it was shown that there exists great potential for detecting and characterising cracking and failure by using a peridynamic-based approach through coupling DIC full displacement field measurements and the critical energy release rate of a particular structural material. / AFRIKAANSE OPSOMMING: Duktiele breeking van materiale word tans beskou as 'n kompleks- en uitdagende fenomeen om te voorspel en te karakteriseer. 'n Binding-gebaseerde, nie-lokale teorie is onlangs geformuleer, genaamd die peridinamika teorie. Die laasgenoemde stel ons in staat om soliede meganiese probleme met krake direk op te los. Die falings kriterium word bemagtig deur die kritiese strekfaktor tussen verbindings. Daar was bewys dat die kritiese strekfaktor in verband staan met die popul^ere breek meganika parameter, genaamd die kritiese vrylatings-energie-koers vir die voorspelling van bros line^ere-elastiese faling. 'n Onlangse verklaring meen dat die kritiese strekfaktor vir duktiele falingsgedrag, bereken kan word met die nie-line^ere kritiese vrylatings-energie-koers, beter bekend as die J- integraal. Die doel van hierdie tesis was om te meet hoe geldig die gebruik van die J-integraal is om die kritiese strekfaktor te bereken, om sodoende duktiele breking te ondersoek. Standaard ASTM breukmeganika toetse op Polimetilmetakrilat, vlekvrye staal 304L en aluminium 1200H4 is uitgevoer om die kritiese vrylatings-energie-koers en Weerstandskurwes te bepaal. Verder was 'n nuwe peridinamies-gebaseerde algoritme ontwikkel. Die laasgenoemde implementeer die berekening van 'n kritiese strekfaktor, gebaseer op die kritiese vrylatings-energie-koers, sowel as Digitale Beeld Korrelasie (BDK) vol oppervlaks-verplasings veld metings van gebreekte materiale. Dit is in staat om die peridinamiese skade te bereken, tesame met die beeld wat veroorsaak was van bros krake en plastiese vervorming in duktiele materiale. Hierdie benadering is aangewend om die gebruik van 'n vrylatings-energie-koers gebaseerde falings kriterium vir bros line^ere-elastiese falings in peridinamika te bekragtig. 'n Goeie korrelasie tussen toets resultate is ook gevind vir die opsporing van skade wat veroorsaak is deur plastiese deformasie in die legerings waar die onderskeilike J-integrale gebruik was as falings kriteria. Daarbenewens, was Verandere Arcan toetse uitgevoer om die Modes I, Modes II en gemenge Modes falingsresultate te verkry. Die Modes I peridinamiese model het goed vergelyk met die toetsresultate en het gedien as bekragtiging vir die falingsbenaderings. Verder was dit aangevoer dat Modes I falings kriterium in beginsel nie gebruik kan word om skuiffaling te modelleer nie. Dus was dit voorgestel om eerder die toepaslike Modes II en gemengde Modes kritieke vrylatings-energie-koerse te gebruik om onderskeie falings te voorspel in peridinamiese modelle. Dit was ook gevind dat vir die voorspelling van duktiele falingslaste die drumpel vrylatings-energie-koers, wat verkrygbaar is vanaf die Weerstands-kurwe, aansienlik meer akkurate resultate gee, in vergelyking met die gebruik van die kritiese vrylatings-energie-koers, m.a.w. die J-integraal. In hierdie tesis was dit gewys dat daar groot potensiaal bestaan vir die opsporing en karakterisering van krake en falings met 'n peridinamies-gebaseerde benadering, deur dit te skakel met BDK vol verplasings veld metings en die kritiese vrylatings-energie-koers van 'n bepaalde strukturele materiaal.
114

Privacy Protecting Surveillance: A Proof-of-Concept Demonstrator / Demonstrator för integritetsskyddad övervakning

Fredrik, Hemström January 2015 (has links)
Visual surveillance systems are increasingly common in our society today. There is a conflict between the demands for security of the public and the demands to preserve the personal integrity. This thesis suggests a solution in which parts of the surveillance images are covered in order to conceal the identities of persons appearing in video, but not their actions or activities. The covered parts could be encrypted and unlocked only by the police or another legal authority in case of a crime. This thesis implements a proof-of-concept demonstrator using a combination of image processing techniques such as foreground segmentation, mathematical morphology, geometric camera calibration and region tracking. The demonstrator is capable of tracking a moderate number of moving objects and conceal their identity by replacing them with a mask or a blurred image. Functionality for replaying recorded data and unlocking individual persons are included. The concept demonstrator shows the chain from concealing the identities of persons to unlocking only a single person on recorded data. Evaluation on a publicly available dataset shows overall good performance.
115

Adherence to and Competence in Cognitive Behavioral Therapy for Youth Anxiety: Psychometric Evaluation

Arnold, Cassidy C 01 January 2015 (has links)
Treatment integrity—the extent to which a treatment is delivered as it was intended—has long been recognized as critically important in treatment evaluation research, but has garnered increased attention in recent years within the context of dissemination and implementation science. However, the field’s development has been hindered by inadequate measurement tools. This project is focused on developing and evaluating the psychometric strength of two measures of treatment integrity. To evaluate the psychometric strength of the Cognitive-Behavioral Therapy for Youth Anxiety Therapist Adherence Scale (CBAY-A)and the Cognitive-Behavioral Therapy for Youth Anxiety Therapist Competence Scale (CBAY-C), 954 psychotherapy sessions from two treatment evaluation studies were coded. Analysis of the evidence for reliability and validity of the item scores for each measure provide substantial support for each measure, while also highlighting areas in need of further evaluation. The discussion focuses on interpreting the psychometric strength of the CBAY-A and CBAY-C compared to other measures of treatment integrity, next steps for evaluating the psychometric strength of the two measures, and potential applications of the CBAY-A and CBAY-C.
116

Barns rätt till integritet : En undersökning av barns rätt till integritet vid vårdnadshavarens internetpublikationer / Children ́s right to integrity : A review of children ́s integrity regarding legal guardians and social media

Ünal, Göknur, Hasselberg, Helen January 2017 (has links)
Resonemanget kring personlig integritet är inget nytt förekommande, men det är däremot användningen av sociala medier som har blivit en naturlig del av människors vardag. Med det växande engagemanget i sociala medier växer ytterligare en debatt, vilket ansvar har en vårdnadshavare vid publicering av bilder och videoklipp på sitt barn, tillsammans med en text som kan anses kränkande? Enligt 6 kap. 11 § Föräldrabalken (1949:381) (FB) har vårdnadshavaren både en rätt och en skyldighet att fatta beslut som rör barnets personliga angelägenheter. Enligt 6 kap. 1 § FB är vårdnadshavaren också skyldig att tillgodose barnet skydd för dennes person och egenart, paragrafen förbjuder också vårdnadshavaren att utsätta barnet för kroppslig skada och kränkande behandling. Barnets rättigheter finns reglerat på två olika nivåer, både nationellt och internationellt. Varje människa oavsett ålder har rätt till privat- och familjeliv enligt artikel 8 Europakonventionen (EKMR). Artikeln omfattar olika perspektiv och rätten till integritet är en av dem. Enligt artikel 19 i barnkonventionen ska det allmänna förhindra att ett barn far illa i hemmet. En central fråga i debatten om barnets rättigheter är barnets kapacitet. Är barnet själv förmögen att kunna fatta välgrundade beslut och inneha självbestämmanderätt? Är barnet tillräckligt moget, intellektuellt och innehar tillräckligt med erfarenhet för att kunna göra rationella bedömningar? Det unga barnets troliga avsaknad av erfarenheter och mognad gör det svårt för barnet att utöva sina rättigheter och det är kanske på grund av detta som barnets rättigheter borde erkännas. Barnet är ibland inte kapabelt att tala för sig själv eller förstå sammanhanget av vad vårdnadshavaren publicerar. Med hänvisning till detta kan det ibland ifrågasättas om vårdnadshavaren spridning av information på sociala medier verkligen utgår från barnets bästa och barnets rätt till integritet. Uppsatsen syfte är att undersöka den problematik som kan uppstå när en vårdnadshavare lägger ut publikationer på barn i sociala medier som kan uppfattas som kränkande. Hur förhåller sig den svenska lagstiftningen, artiklarna i EKMR och barnkonventionen till detta? Kan barnets personliga integritet och rättigheter komma i konflikt med vårdnadshavarens intresse genom publiceringar på sociala medier? Genom undersökningen som gjorts i uppsatsen kan det konstateras att det finns en möjlighet för vårdnadshavaren att via internetpublikationer kränka barnets rätt till integritet. Det saknas i dagsläget direkta lagrum i svensk rätt för att skydda barnet i ovanstående hänseendet. Ett förtydligande i lagen där barn särskilt omnämns eller en inkorporering av barnkonventionen kan medföra ett starkare skydd för barns rätt till integritet på sociala medier. / The discussion concerning personal integrity is nothing new with regards to the use of social media, which has become a natural part of everyday life. With the growth of social media comes another debate, concerning what responsibility the guardian has when it comes to posting pictures and videos of their children, along with a text that can be considered offensive on social media? According to chapter 6. 11 § in the parental code the guardian has a right and an obligation to make decisions concerning the child's personal matters. According to chapter 6. § 1 in the parental code the guardian is also required to supply children with protection from their own actions. The article also prohibits the guardian to expose the child to bodily injury and offensive treatment. Children's rights are regulated at two different levels, both nationally and internationally. Every person, regardless of age has the right to privacy in family life according to article 8 of the European Convention (ECHR). The article covers different perspectives and the right to privacy is one of them. Article 19 in the UN Convention on the Rights of the Child requires the public to prevent that a child is being abused in the home environment. A central issue in the debate about child rights is the child's capacity. Is the child able to make well-grounded decisions and do they have a right to self-determination? Is the child mature enough, intellectual enough and hold enough experience to be able to make rational judgments? The young child's probable lack of experience and maturity makes it difficult for them to exercise their rights and it is perhaps because of this that childrens rights should be recognised. The child is sometimes not able to speak for himself or understand the context of what the guardian publishes on social media. With reference to this, the guardian’s dissemination of information on social media should be questioned - is it really based with the best interests of the child in mind and their right to privacy. The essay aims to examine the problems that can arise when a guardian publishes pictures of their children on social media that may be perceived as offensive. How does the Swedish legislation, the articles of the ECHR and the Convention deal with this scenario? Can the child's privacy and rights come into conflict with the guardian's interest in making publications on social media? The survey carried out in the essay states that there is a possibility for the guardian to violate the child's right to privacy through internet publications. Swedish law is missing sections of the law to protect the child of the regarding above. A clarification of the law where children are specifically referred to or a incorporation of the UN Convention on the Rights of the Child can result in greater protection for children's right to personal integrity on social media.
117

Study and analysis of surface layer characteristics of lead brass and lead free brass

Challapalli, Dharmendra, El-masri, Ahmad January 2016 (has links)
The addition of lead to the copper alloys increase the machinability of thework material (without reference here to environmental factors) and reduces the overall production cost of the components at different stages, despite copper being expensive, which makes a challenging task to replace lead. Since lead is dangerous to human health. Many materials are considered to replace lead in brass and silicon is one of the alternative. This thesis characterizes the lead and the lead free brass's surfacemetallurgy for a certain cutting data. The study includes identification of alteredmaterial zones (AMZ) defined by the plastic deformation, hardness alterationsand grain distributions.The study results include the analysis of deformed subsurface region andcomparison exemplifying differences between the two materials under twodifferent studies. / Lead free brass
118

Effects of catchment management on physical river condition, chemistry, hydrogeomorphology and ecosystem service provision in small coastal rivers of the Western Cape

Petersen, Chantel R. January 2019 (has links)
Philosophiae Doctor - PhD / River systems are by nature complex and dynamic systems, which vary in structure and therefore function, and are closely connected to their landscapes. The primary aim of this thesis was to develop a systems operational understanding of how river patterns and processes (geomorphology and hydrology) link to aquatic and riparian systems and biodiversity (ecology) in a framework of evolving land cover/use and management. This illustrated the hydrogeomorphic controls regulating the structure and functioning of rivers in the provision of goods and services that vegetation, especially riparian vegetation, perform as ecological infrastructure, with a focus on the Duiwe River catchment. This study used a combination of desktop and field analysis. The desktop analysis followed the spatial and temporal historical land use change detection of river sub-catchments to assess the influence on water quality and river flow. It included historical water quality, flow records, rainfall data and aerial photograph time series analysis for trend detection, which were linked to changes in land use activities. The field surveys included cross-section surveys, physical and chemical sediment analysis, vegetation distribution, ground-water depth surveys and instream biological surveys of aquatic bioindicators. The study illustrated a correlation between land cover/use, water quality and river ecological integrity. When spatial heterogeneity of the catchments was altered by human or natural events, it was reflected by changes in the water quality. The linkages between the land cover/use and ecological integrity were examined using macroinvertebrates and algae. Macroinvertebrates were indicative of habitat integrity and river condition, while the benthic filamentous algae were indicative of increased nutrients and alkalinity. Results indicated that the full consortium of algae and macroinvertebrates be used as bioindicators for ecological integrity assessments in these short, coastal rivers. The influence of riparian vegetation and its effectiveness in providing regulating (retaining sediment and nutrients) and provisioning (good water quality for humans and the aquatic environment) services was examined by relating contrasting land uses, riparian vegetation, nutrient dynamics and water quality. The land covers generated different runoff volumes, water quality parameter concentrations and associated nutrient loads. Agriculture and alien Acacia mearnsii trees had the greatest impact on nutrient loads. However, a decreasing trend in nutrient concentrations was observed in the cross-section from the pastures to the riparian zones to the river at all sites. The key findings from this study were formulated into a conceptual framework flow-chain model demonstrating the linkages between river pattern, processes and ecology in the provision of ecosystem services. This interdisciplinary investigation demonstrated strong links between climate, topography, hydrogeomorphology, land cover/use, human activities and their influence on ecological river integrity. The developed framework provides a hierarchical model to link the different disciplines. It illustrates the top-down constraints provided by the system controllers and habitat drivers, coupled with the anthropogenic impacts as controllers to determine the response of biological entities (riparian vegetation and aquatic biota) at different scales, to ultimately provide ecosystem services. It provides the basis for an understanding of the linkages, processes and interactions that allows, prevents or alters ecosystem service provision by river ecosystems and in the study context, by riparian buffer zones.
119

Categorical data imputation using non-parametric or semi-parametric imputation methods

Khosa, Floyd Vukosi 11 May 2016 (has links)
A research report submitted to the Faculty of Science, University of the Witwatersrand, for the degree of Master of Science by Coursework and Research Report. / Researchers and data analysts often encounter a problem when analysing data with missing values. Methods for imputing continuous data are well developed in the literature. However, methods for imputing categorical data are not well established. This research report focuses on categorical data imputation using non-parametric and semi-parametric methods. The aims of the study are to compare different imputation methods for categorical data and to assess the quality of the imputation. Three imputation methods are compared namely; multiple imputation, hot deck imputation and random forest imputation. Missing data are created on a complete data set using the missing completely at random mechanism. The imputed data sets are compared with the original complete data set, and the imputed values which are the same as the values in the original data set are counted. The analysis revealed that the hot deck imputation method is more precise, compared to random forest and multiple imputation methods. Logistic regression is fitted on the imputed data sets and the original data set and the resulting models are compared. The analysis shows that the multiple imputation method affects the model fit of the logistic regression negatively.
120

I andan av #metoo : En undersökning om intregiritet i förskolan

Skarin, Tindra, Rylander, Emma January 2019 (has links)
During the past few years debates such as #metoo has led to more discussions about children’s rights to integrity. The aim of this study is to investigate how preschool teachers interpret and work with integrity in preschool. The questions for this study are the three following: How is integrity described in relation to preschool? Which methods are used in preschool for working with integrity? Why is it of importance to work with children’s integrity in preschool? Our study is based on interviews with six preschool teachers. All of them have been interviewed in couples. Each couple has been interviewed two times. We have four theoretical concepts in this study. The first is Juul and Jensens theoretical concept of integrity, which deem that integrity occurs when our internal responsibility conflicts with our external responsibility. Integrity occurs when what I feel is not in balance with what society demands of me (Juul & Jensen 2003). The second theoretical concept is the Self theory by Daniel Stern through Brodin and Hylander. Stern means that from our births we have an inner core which evolves to what we call our inner self (Brodin & Hylander 1997). Our third theoretical concept is Foucault’s theory of power through Börjesson and Rehn and through Juul and Jensen. Börjesson and Rehn describes power as something that is always present and constantly floating in social relationships and events. As an adult, your experience and knowledge imply that you are more often in a position of power than a child (Börjesson & Rehn). Juul and Jensen describes a specific kind of power: definition power. This power means that adults in a greater extent than children possess the right to define what is right and wrong (Juul & Jensen 2003). The last theoretical concept is a theory about the competent child, described by Brodin and Hylander. In this theory children are aware of their dependence of other people to care for them and are therefore in search for both knowledge and social interplay with other people (Brodin & Hylander 1997). The result of this study shows that integrity in preschool is described as the physical integrity and the right to decide over your own body. The teachers described that children must learn different ways of showing their boundaries, and to become responsive to the limits of others. The teachers describe various types of materials and methods for learning the children about integrity. Learning about your own and other’s boundaries is important both for becoming part of a society and for reducing sexual violence.

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