Representing and reasoning with qualitative preferences for compositional systems

Many applications call for techniques for representing and reasoning about preferences, i.e., relative desirability over a set of alternatives. Preferences over the alternatives are typically derived from preferences with respect to the various attributes of the alternatives (e.g., a student\u27s preference for one course over another may be influenced by his preference for the topic, the time of the day when the course is offered, etc.). Such preferences are often qualitative and conditional. When the alternatives are expressed as tuples of valuations of the relevant attributes, preferences between alternatives can often be expressed in the form of (a) preferences over the values of each attribute, and (b) relative importance of certain attributes over others. An important problem in reasoning with multi-attribute qualitative preferences is dominance testing, i.e., to find if one alternative (assignment to all attributes) is preferred over another. This problem is hard (PSPACE-complete) in general for well known qualitative conditional preference languages such as TCP-nets. We provide two practical approaches to dominance testing. First, we study a restricted unconditional preference language, and provide a dominance relation that can be computed in polynomial time by evaluating the satisfiability of an appropriately constructed logic formula. Second, we show how to reduce dominance testing for TCP-nets to reachability analysis in an induced preference graph. We provide an encoding of TCP-nets in the form of a Kripke structure for CTL. We show how to compute dominance using NuSMV, a model checker for CTL. We address the problem of identifying a preferred outcome in a setting where the outcomes or alternatives to be compared are composite in nature (i.e., collections of components that satisfy certain functional requirements). We define a dominance relation that allows us to compare collections of objects in terms of preferences over attributes of the objects that make up the collection, and show that the dominance relation is a strict partial order under certain conditions. We provide algorithms that use this dominance relation to identify only (sound), all (complete), or at least one (weakly complete) of the most preferred collections. We establish some key properties of the dominance relation and analyze the quality of solutions produced by the algorithms. We present results of simulation experiments aimed at comparing the algorithms, and report interesting conjectures and results that were derived from our analysis. Finally, we show how the above formalism and algorithms can be used in preference-based service composition, substitution, and adaptation

Privacy-preserved security-conscious framework to enhance web service composition

The emergence of loosely coupled and platform-independent Service-Oriented Computing (SOC) has encouraged the development of large computing infrastructures like the Internet, thus enabling organizations to share information and offer valueadded services tailored to a wide range of user needs. Web Service Composition (WSC) has a pivotal role in realizing the vision of implementing just about any complex business processes. Although service composition assures cost-effective means of integrating applications over the Internet, it remains a significant challenge from various perspectives. Security and privacy are among the barriers preventing a more extensive application of WSC. First, users possess limited prior knowledge of security concepts. Second, WSC is hindered by having to identify the security required to protect critical user information. Therefore, the security available to users is usually not in accordance with their requirements. Moreover, the correlation between user input and orchestration architecture model is neglected in WSC with respect to selecting a high performance composition execution process. The proposed framework provides not only the opportunity to securely select services for use in the composition process but also handles service users’ privacy requirements. All possible user input states are modelled with respect to the extracted user privacy preferences and security requirements. The proposed approach supports the mathematical modelling of centralized and decentralized orchestration regarding service provider privacy and security policies. The output is then utilized to compare and screen the candidate composition routes and to select the most secure composition route based on user requests. The D-optimal design is employed to select the best subset of all possible experiments and optimize the security conscious of privacy-preserving service composition. A Choreography Index Table (CIT) is constructed for selecting a suitable orchestration model for each user input and to recommend the selected model to the choreographed level. Results are promising that indicate the proposed framework can enhance the choreographed level of the Web service composition process in making adequate decisions to respond to user requests in terms of higher security and privacy. Moreover, the results reflect a significant value compared to conventional WSC, and WSC optimality was increased by an average of 50% using the proposed CIT

Modeling and Selection of Software Service Variants

Providers and consumers have to deal with variants, meaning alternative instances of a service?s design, implementation, deployment, or operation, when developing or delivering software services. This work presents service feature modeling to deal with associated challenges, comprising a language to represent software service variants and a set of methods for modeling and subsequent variant selection. This work?s evaluation includes a POC implementation and two real-life use cases

Automatic Dynamic Web Service Composition: A Survey and Problem Formalization

The aim of Web service composition is to arrange multiple services into workflows supplying complex user needs. Due to the huge amount of Web services and the need to supply dynamically varying user goals, it is necessary to perform the composition automatically. The objective of this article is to overview the issues of automatic dynamic Web service composition. We discuss the issues related to the semantics of services, which is important for automatic Web service composition. We propose a problem formalization contributing to the formal definition of the pre-/post-conditions, with possible value restrictions, and their relation to the semantics of services. We also provide an overview of several existing approaches dealing with the problem of Web service composition and discuss the current achievements in the field and depict some open research areas

A graph-based framework for optimal semantic web service composition

Web services are self-described, loosely coupled software components that are network-accessible through standardized web protocols, whose characteristics are described in XML. One of the key promises of Web services is to provide better interoperability and to enable a faster integration between systems. In order to generate robust service oriented architectures, automatic composition algorithms are required in order to combine the functionality of many single services into composite services that are able to respond to demanding user requests, even when there is no single service capable of performing such task. Service composition consists of a combination of single services into composite services that are executed in sequence or in a different order, imposed by a set of control constructions that can be specified using standard languages such as OWL-s or BPEL4WS. In the last years several papers have dealt with composition of web services. Some approaches treat the service composition as a planning problem, where a sequence of actions lead from a initial state to a goal state. However, most of these proposals have some drawbacks: high complexity, high computational cost and inability to maximize the parallel execution of web services. Other approaches consider the problem as a graph search problem, where search algorithms are applied over a web service dependency graph in order to find a solution for a particular request. These proposals are simpler than their counterparts and also many can exploit the parallel execution of web services. However, most of these approaches rely on very complex dependency graphs that have not been optimized to remove data redundancy, which may negatively affect the overall performance and scalability of these techniques in large service registries. Therefore, it is necessary to identify, characterize and optimize the different tasks involved in the automatic service composition process in order to develop better strategies to efficiently obtain optimal solutions. The main goal of this dissertation is to develop a graph-based framework for automatic service composition that generate optimal input-output based compositions not only in terms of complexity of the solutions, but also in terms of overall quality of service solutions. More specifically, the objectives of this thesis are: (1) Analysis of the characteristics of services and compositions. The aim of this objective is to characterize and identify the main steps that are part for the service composition process. (2) Framework for automatic graph-based composition. This objective will focus on developing a framework that enables the efficient input-output based service composition, exploring the integration with other tasks that are part of the composition process, such as service discovery. (3) Development of optimal algorithms for automatic service composition. This objective focuses on the development of a set of algorithms and optimization techniques for the generation of optimal compositions, optimizing the complexity of the solutions and the overall Quality-of- Service. (4) Validation of the algorithms with standard datasets so they can be compared with other proposals

Emotional antecedents of customer loyalty in the formal retail industry of South Africa

Text in English with abstracts in Zulu and AfrikaansDespite its substantial growth and contribution to the economy of the country, the South African retail industry is faced with various challenges, including customers’ changing buying habits and expectations, the evolution of e-commerce, the entry of giant retailers into the retail market, and the growing importance of the urbanised middle class and its potential purchasing power. This creates risks that are mostly beyond retailers’ control. Therefore, there is a general drive among retail brands to build customer loyalty in order to respond to these contemporary dynamics within the industry and, ultimately, enhance sustainability. It is noted from literature that current understanding of customer behaviour in the South African retail space is largely the result of rational behavioural measurement, while the subconscious behaviour of customers is often neglected. The study on which this thesis reports attempted to address this gap in the current knowledge base. The current study makes a novel contribution to knowledge in using complementary traditional and neuromarketing instruments in a sequential mixed method research design to measure verbal, non-verbal and physiological emotions, which indicate the key influential cognitive and emotive factors shaping shopping decisions. For a comprehensive understanding of customer behaviour, the study primarily explored the emotional antecedents of customer loyalty in the formal retail industry of South Africa. In order to explore and describe both retail brands and customers’ experiences regarding the drivers of retail brand loyalty, the empirical phase of the study adopted a sequential mixed method research design. This design comprised eight individual semi-structured interviews, which focused on and explored the fundamentals of behavioural and attitudinal loyalty within the context of a customer relationship management strategy. x Based on the findings emerging from the quantitative mall intercept survey with 300 retail customers, the study identified the motivating factors of greatest likelihood among customers that best explain retail brand loyalty, namely product quality, convenience of location, customer care, product variety and availability, as well as fair pricing. Furthermore, findings emerging from the inferential analysis (structural equation modelling, two-step cluster analysis, optimal scaling and multivariate binary regression analysis) showed that brand trust, brand affect and attitudinal loyalty are key predictors of behavioural loyalty. Additionally, customer loyalty differs depending on customer predisposition towards the major retail brands tested. In this regard, Pick n Pay, Massmart and Shoprite/Checkers recorded the most favourable perceptions among customers. As Despite its substantial growth and contribution to the economy of the country, the South African retail industry is faced with various challenges, including customers’ changing buying habits and expectations, the evolution of e-commerce, the entry of giant retailers into the retail market, and the growing importance of the urbanised middle class and its potential purchasing power. This creates risks that are mostly beyond retailers’ control. Therefore, there is a general drive among retail brands to build customer loyalty in order to respond to these contemporary dynamics within the industry and, ultimately, enhance sustainability. It is noted from literature that current understanding of customer behaviour in the South African retail space is largely the result of rational behavioural measurement, while the subconscious behaviour of customers is often neglected. The study on which this thesis reports attempted to address this gap in the current knowledge base. The current study makes a novel contribution to knowledge in using complementary traditional and neuromarketing instruments in a sequential mixed method research design to measure verbal, non-verbal and physiological emotions, which indicate the key influential cognitive and emotive factors shaping shopping decisions. For a comprehensive understanding of customer behaviour, the study primarily explored the emotional antecedents of customer loyalty in the formal retail industry of South Africa. In order to explore and describe both retail brands and customers’ experiences regarding the drivers of retail brand loyalty, the empirical phase of the study adopted a sequential mixed method research design. This design comprised eight individual semi-structured interviews, which focused on and explored the fundamentals of behavioural and attitudinal loyalty within the context of a customer relationship management strategy. x Based on the findings emerging from the quantitative mall intercept survey with 300 retail customers, the study identified the motivating factors of greatest likelihood among customers that best explain retail brand loyalty, namely product quality, convenience of location, customer care, product variety and availability, as well as fair pricing. Furthermore, findings emerging from the inferential analysis (structural equation modelling, two-step cluster analysis, optimal scaling and multivariate binary regression analysis) showed that brand trust, brand affect and attitudinal loyalty are key predictors of behavioural loyalty. Additionally, customer loyalty differs depending on customer predisposition towards the major retail brands tested. In this regard, Pick n Pay, Massmart and Shoprite/Checkers recorded the most favourable perceptions among customers. As a complement to the quantitative research phase of the study, a Self-Assessment Manikin attitude measure was applied to a sample of 120 customers. This phase of the study highlighted pertinent emotional elements as key mediators in securing sustainable retail brand loyalty. In this regard, Woolworths and Pick n Pay recorded the most favourable perceptions on four stimuli, namely quality, customer rewards, customer care and brand logos. The study also applied eye tracking and galvanic skin response techniques to a sample of 10 participants to determine customers’ psychophysiological reaction to the four stimuli. Galvanic skin response findings showed that customers were especially engaged with Spar, Shoprite/Checkers and Pick n Pay, while eye tracking findings showed customers’ higher visual engagement with Shoprite/Checkers, Pick n Pay and Spar. A key overall finding of this study was the significant role of feelings and emotions in driving customer loyalty. Retail brands lose relevance when they fail to connect emotionally with customers, and without that emotional attachment, brands can easily be replaced by generic imposters. A comprehensive understanding of customer behaviour remains a quandary for marketing and business practitioners. In an attempt to address this limitation, the current study used insights from non-verbal attitudinal and psychophysiological measures to obtain a more comprehensive behavioural understanding of retail customers.Nakuba imboni yezitolo ezihwebayo yaseNingizimu Afrika ibonise ukukhula nokudlondlobala okukhulu futhi idlala indima esemqoka emnothweni wezwe, ibhekene nezinselelo eziningana futhi ezihlukahlukene, kubandakanya indlelakuthenga yamakhasimende eguquguqukayo kanye nalokho okulindelwe ngamakhasimende nezimfuno zawo, ukungenisa ngezinkani kwemboni yokuhweba nge-intanethi nobuxhakaxhaka bobuchwepheshe besimanjemanje, ukungena kwezitolo eziyizikhondlakhondla emakethe yezitolo ezihwebayo, kanye nokukhula kokubaluleka kwabantu abahlala emadolobheni abasesigabeni sempilo esimaphakathi kanye namandla abo okuthenga. Lokhu kudala ubungozi obuvamise ukuba ngaphezu kwamandla nolawulo lwezitolo ezihwebayo. Ngakho-ke, kunomkhankaso oqhutshwa yizitolo zonkana ezihlose ngawo ukwakha ubudlelwano namakhasimende kanye nokuqinisekisa ukwethembeka kwamakhasimende ukuze zikwazi ukumelana nezimo ezikhona esikhathini samanje embonini yezitolo ezihwebayo, futhi ekugcineni, ukuze zikwazi ukusimamisa ibhizinisi lazo liqhubeke njalo futhi likhule lidlondlobale. Kuphawulekile emibhalweni efundiwe ukuthi ukuqonda kanye nolwazi olujulile olukhona njengamanje mayelana nokuziphatha kwamakhasimende eNingizimu Afrika emkhakheni wezitolo ezihwebayo ikakhulukazi kuwumphumela wokukalwa kwezinga lokuthatha izinqumo ngobuhlakani nokwenza izinto emva kokucabangisisa, kepha-ke ngakolunye uhlangothi kuvamise ukushaywa indiva ukwenza izinto kwamakhasimende ngaphandle kokuqaphela nokucophelela futhi ngokuthathela izinto phezulu noma ngaphandle kokucabangisisa ngalokho akwenzayo. Lolu cwaningo okubikwa ngalo kulo mbiko wocwaningo luzamile ukubhekana naleli gebe elikhona njengamanje eliphathelene nokuntuleka kolwazi. Lolu cwaningo lwamanje lufaka isandla esinohlonze kanye nemibono ephusile olwazini olukhona, ngokusebenzisa amathuluzi asekelayo ajwayelekile kanye nalawo asebenzisa ubuchwepheshe bokukala ukusebenza kwengqondo, ngaphansi kwedizayini yocwaningo egxile kwindlela-kusebenza exubile yokwenza izinto ngokulandelana kwazo, ngenhloso yokukala imizwa ezwakaliswa ngomlomo, ngezenzo noma ngeminyakazo yomzimba, okuyinto ebonisa izimo nezici-bunjalo ezisemqoka futhi ezinomthelela omkhulu eziphathelene nokusebenza kwengqondo kanye nemizwa, okuyizona ezilawula izinqumo zamakhasimende eziphathelene nokuthenga. Ngenhloso yokuqonda ngokuphelele ukuziphatha kwamakhasimende, lolu cwaningo lwacubungula futhi lwahlaziya ikakhulukazi izici-bunjalo zemizwa elawula ukwethembeka kwamakhasimende embonini yezitolo ehlelekile yaseNingizimu Afrika. Ukuze kucutshungulwe futhi kuchazwe kokubili izinhlobo zezitolo kanye nezimo ahlangabezane nazo amakhasimende mayelana nezici-bunjalo ezenza amakhasimende athembeke esitolo esithile futhi athenge kusona ngaso sonke isikhathi, isigaba socwaningo esiphathelene nolwazi oluphathekayo nolubonakalayo sasebenzisa idizayini yocwaningo egxile kwindlela-kusebenza exubile yokwenza izinto ngokulandelana kwazo. Le dizayini beyibandakanya ama-semi-structured interviews enziwa nababambiqhaza bocwaningo abayisishiyagalombili, okuyizingxoxo ezabe zigxile ekucubunguleni ukwethembeka kwamakhasimende okuphathelene nokuziphatha kwawo kanye nendlela abuka ngayo izinto ngaphansi kwesimo seqhingasu lokuphathwa kobudlelwano namakhasimende. Ngokususela kwimiphumela eyatholakala kwinhlolovo ebandakanya abathengi abangama-300 okwaxoxiswana nabo ezikhungweni ezinenxanxathela yezitolo, ucwaningo lwahlonza izimo nezi-bunjalo ezikhuthaza futhi zihehe amakhasimende okuyizona ezingasetshenziswa ukuchaza kangcono ukwethembeka kwamakhasimende ezitolo ezithile, okuyikhwalithi yomkhiqizo, ukufinyeleleka kalula kwendawo lapho kutholakala khona isitolo, ukunakekelwa kwamakhasimende, imikhiqizo ehlukahlukene kanye nokutholakala kwayo, ngokunjalo namanani-ntengo angambi eqolo. Ngaphezu kwalokho, imiphumela eyatholakala ohlaziyweni lwezinqumo ezithathwe ngokubheka ubufakazi kanye nokuqonda okujulile (structural equation modelling, two-step cluster analysis, optimal scaling kanye ne-multivariate binary regression analysis) yabonisa ukuthi ukwethenjwa kohlobo lomkhiqizo, ukukhanga nokuthandeka komkhiqizo kanye nokwethembeka okuphathelene nendlela-kubuka kuyizibikezeli ezisemqoka zokuziphatha kwamakhasimende okuhambisana nokwethembeka emikhiqizweni ethile. Futhi ngaphezu kwalokho, ukwethembeka kwamakhasimende kuyehluka, futhi lokhu kuncike ekuhehelekeleni kwamakhasimende ezitolo enkulu ezihloliwe. Mayelana nalokhu-ke, abakwa-Pick n Pay, Massmart kanye nabakwa-Shoprite/Checkers yizona zitolo ezibonise ukuthandwa kakhulu ngamakhasimende. Njengendlela yokweseka nokunezezela phezu kwesigaba socwaningo olukhwantithethivu olwenziwe, kwasetshenziswa isikali sendlela-kubuka esibizwa nge-Self-Assessment Manikin kwisampula yamakhasimende ayi-120. Lesi sigaba socwaningo saqhakambisa izimo nezici-bunjalo eziphathelene nemizwa ezifanelekile njengezinto ezisemqoka kakhulu ekuqinisekiseni ukwethembeka kwamakhasimende esitolo esithile ngokuqhubekayo. Mayelana nalokhu, abakwa-Woolworths kanye nabakwa-Pick n Pay babonisa ukuthandwa kakhulu ngamakhasimende mayelana nezici-bunjalo ezihehayo futhi ezikhuthazayo ezine, okuyikhwalithi, imivuzo yamakhasimende, ukunakekelwa kwamakhasimende kanye nemibala egqamile, igama elidumile nezimpawu zesitolo. Ucwaningo lwasebenzisa futhi nezindlela zokucwaninga eziphathelene nokulandela umkhondo wamehlo amakhasimende kanye nezimpawu zemizwa yamakhasimende ezibonakala esikhumbeni semizimba yawo, okuyizindlela zocwaningo ezasetshenziswa kubabambiqhaza bocwaningo abayi-10 ngenhloso yokuhlonza indlela-kusabela kwamakhasimende ephathelene nengqondo nomzimba kulezi zicibunjalo ezikhuthazayo futhi ezihehayo ezine ezishiwo ngenhla. Imiphumela yendlela yocwaningo ebheka izimpawu zemizwa yamakhasimende ezibonakala esikhumbeni semizimba yawo yabonisa ukuthi amakhasimende ahehelekela ikakhulukazi kwabakwa-Spar, Shoprite/Checkers kanye nabakwa-Pick n Pay, kanti ngakolunye uhlangothi imiphumela yendlela yocwaningo ebheka futhi ilandele umkhondo wamehlo amakhasimende yabonisa ukuheheka kwamehlo okuphakeme ezitolo zabakwa-Shoprite/Checkers, Pick n Pay kanye nabakwa-Spar. Umphumela omkhulu futhi osemqoka otholakale kulolu cwaningo yindima ebaluleke kakhulu edlalwa yimizwa ekukhuthazeni ukwethembeka kwamakhasimende. Izitolo zilahlekelwa yiwozawoza yazo kumakhasimende uma zihluleka ukuxhumana namakhasimende ngokwemizwa, futhi ngaphandle kwalokho kuxhumana ngokwemizwa nokuzwana, izitolo zingazithola kalula zisesimweni lapho indawo yazo isithathwe yizitolo-mbumbulu ezingosandanezwe. Ukuqondakala okuphelele kwendlela aziphatha ngayo amakhasimende futhi enza ngayo izinto kusalokhu kuyinkinga nesithiyo esikhulu kwizazi nezisebenzi ezenza umsebenzi wokukhangisa nokuqhuba ibhizinisi. Njengomzamo wokubhekana nalesi sithiyo, lolu cwaningo lusebenzise ulwazi nokuqonda okujulile okutholakale kwizikali zendlela-kubuka yamakhasimende kanye nezikali zesimo sengqondo nesomzimba samakhasimende ukuze kutholakale ukuqonda okuphelele futhi okujulile okuphathelene nokuziphatha kwamakhasimende athenga ezitolo kanye nendlela enza ngayo izinto.Ondanks sy stewige groei en aansienlike bydrae tot die landsekonomie, het die Suid-Afrikaanse kleinhandelsbedryf met verskeie uitdagings te kampe. Veranderinge in kliënte se koopgewoontes en verwagtings, groeiende e-handel, reusekleinhandelaars wat die kleinhandelsmark betree, die toenemende invloed van die verstedelikte middelklas en sy potensiële koopkrag is enkele hiervan. Dit gee aanleiding tot risiko’s wat grotendeels buite die beheer van kleinhandelaars is. As gevolg van die hedendaagse dinamiek in die bedryf, poog kleinhandelsmerke om kliëntlojaliteit te verstewig en hulle eie volhoubaarheid te verseker. Dit blyk uit die literatuur dat die kleinhandelsektor se siening van kliëntgedrag in Suid-Afrika op die meting van rasionele gedrag berus, en dat die onbewuste gedrag van kliënte verontagsaam word. Hierdie tesis doen verslag van ʼn studie om hierdie leemte in die huidige kennis te probeer aanvul. Dit lewer ʼn bydrae deur aanvullende tradisionele en neurobemarkingsinstrumente in ʼn opeenvolgende gemengde metode as navorsingsbenadering te gebruik. Verbale, nieverbale en fisiologiese emosies is gemeet aangesien hulle die kognitiewe en emotiewe faktore is wat inkopiebesluite bepaal. Hierdie studie het hoofsaaklik die emosionele antesedente van kliëntlojaliteit in die Suid-Afrikaanse formele kleinhandelsbedryf verken om ʼn grondige begrip van kliëntgedrag te kry. Ten einde kleinhandelsmerke en kliënte se ervarings van die drywers van kleinhandelsmerklojaliteit te beskryf en te verken, is ʼn opeenvolgende gemengdemetode-navorsingsontwerp gevolg. Dit het uit agt halfgestruktureerde, private onderhoude bestaan. Hierin is gekonsentreer op die grondslae van gedragsen houdingslojaliteit teen die agtergrond van ʼn kliënteverhoudingsbestuurstrategie. Op grond van die bevindings van ʼn kwantitatiewe winkelsentrumopname onder 300 kleinhandelskliënte, is die motiveringsfaktore met die grootste waarskynlikheid aangetoon. Hulle is produkgehalte, ʼn gerieflike ligging, kliëntesorg, produkverskeidenheid, beskikbaarheid en billike pryse, en bied die aanneemlikste verklaring vir kleinhandelsmerklojaliteit. Volgens die bevindings van die inferensiële ontleding (struktuurvergelykingmodellering, tweestaptrosontleding, optimale skalering en meerveranderlike binêre regressieanalise) is merkvertroue, merkaffek en houdingslojaliteit betroubare aanwysers van bedragslojaliteit. Afgesien hiervan verskil kliëntlojaliteit na gelang van kliëntpredisposisie jeens kleinhandelsmerke wat getoets is. Kliënte was vir vier stimuli (naamlik gehalte, kliëntbelonings, kliëntesorg en merklogo’s) die ontvanklikste vir Pick n Pay, Massmart en Shoprite/Checkers. Aanvullend tot die kwalitatiewe navorsingsfase van hierdie studie is ʼn selfasseringsmodelhoudingmeting op ʼn steekproef van 120 kliënte toegepas. Hierdie fase het die aandag gevestig op pertinente emosionele elemente as sleuteltussengangers in die opwekking van volhoubare kleinhandelsmerklojaliteit. Vir die vier stimuli (naamlik gehalte, kliëntbelonings, kliëntesorg en merklogo’s) was kliënte se persepsies van Woolworths en Pick n Pay die gunstigste. Hierbenewens is oogvolg- en galvaniese velreaksietegnieke op ʼn steekproef van 10 deelnemers toegepas om hulle psigofisiologiese reaksie op die vier stimuli te bepaal. Die galvaniese velreaksietoetse het aangedui dat kliënte besonder ontvanklik was vir Spar, Shoprite/Checkers en Pick n Pay, en volgens die oogvolgtoetse visueel meer aangetrokke tot Spar, Shoprite/Checkers en Pick n Pay was. Hierdie studie het bevind dat emosies in die algemeen ʼn deurslaggewende rol in kliëntlojaliteit speel. Kleinhandelsmerke raak irrelevant as hulle nie ʼn emosionele band met kliënte smee nie. Sonder hierdie emosionele verbintenis kan generiese bedrieërs maklik die plek van kleinhandelsmerke inneem. Bemarkings- en sakepraktisyns het nie ʼn deeglike begrip van kliëntgedrag nie. Om dit reg te stel, het hierdie studie nieverbale houdings- en psigofisiologiese toetse toegepas om die gedrag van kleinhandelskliënte beter te begryp.Business ManagementD. Com. (Business Management

Methods and algorithms for service selection and recommendation (preference and aggregation based)

In order for service users to get the best service that meets their requirements, they prefer to personalize their non-functional attributes, such as reliability and price. However, the personalization makes it challenging because service providers have to deal with conflicting non-functional attributes when selecting services for users. In addition, users may sometimes want to explicitly specify their trade-offs among non-functional attributes to make their preferences known to service providers. Typically, users\u27 service search requests with conflicting non-functional attributes may result in a ranked list of services that partially meet their needs. When this happens, it is natural for users to submit other similar requests, with varying preferences on non-functional attributes, in an attempt to find services that fully meet their needs. This situation produces a challenge for the users to choose an optimal service based on their preferences, from the multiple ranked lists that partially satisfy their request. Existing memory-based collaborative filtering (CF) service recommendation methods that employ this recommendation technique usually depend on non-functional attribute values obtained at service invocation to compute the similarity between users or items, and also to predict missing non-functional attributes. However, this approach is not sufficient because the non-functional attribute values of invoked services may not necessarily satisfy their personalized preferences. The main contributions of this work are threefold. First, a novel service selection method, which is based on fuzzy logic, that considers users\u27 personalized preferences and their trade-offs on non-functional attributes during service selection is presented. Second, a method that aggregates multiple ranked lists of services into a single aggregated ranked list, where top ranked services are selected for the user is also presented. Two algorithms were proposed: 1) Rank Aggregation for Complete Lists (RACoL), that aggregates complete ranked lists and 2) Rank Aggregation for Incomplete Lists (RAIL) to aggregate incomplete ranked lists. Finally, a CF-based service recommendation method that considers users\u27 personalized preference on non-functional attributes if proposed. Examples using real-world services are presented to evaluate the proposed methods and experiments are carried out to validate their performance --Abstract, page iii

A service broker for Intercloud computing

This thesis aims at assisting users in finding the most suitable Cloud resources taking into account their functional and non-functional SLA requirements. A key feature of the work is a Cloud service broker acting as mediator between consumers and Clouds. The research involves the implementation and evaluation of two SLA-aware match-making algorithms by use of a simulation environment. The work investigates also the optimal deployment of Multi-Cloud workflows on Intercloud environments