• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1251
  • 290
  • 264
  • 197
  • 186
  • 60
  • 56
  • 55
  • 40
  • 34
  • 22
  • 20
  • 16
  • 12
  • 11
  • Tagged with
  • 2958
  • 916
  • 531
  • 508
  • 398
  • 390
  • 385
  • 332
  • 319
  • 289
  • 275
  • 273
  • 228
  • 211
  • 206
  • 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.
151

Ensuring the Reliable Operation of the Power Grid: State-Based and Distributed Approaches to Scheduling Energy and Contingency Reserves

Prada, Jose Fernando 01 December 2017 (has links)
Keeping a contingency reserve in power systems is necessary to preserve the security of real-time operations. This work studies two different approaches to the optimal allocation of energy and reserves in the day-ahead generation scheduling process. Part I presents a stochastic security-constrained unit commitment model to co-optimize energy and the locational reserves required to respond to a set of uncertain generation contingencies, using a novel state-based formulation. The model is applied in an offer-based electricity market to allocate contingency reserves throughout the power grid, in order to comply with the N-1 security criterion under transmission congestion. The objective is to minimize expected dispatch and reserve costs, together with post contingency corrective redispatch costs, modeling the probability of generation failure and associated post contingency states. The characteristics of the scheduling problem are exploited to formulate a computationally efficient method, consistent with established operational practices. We simulated the distribution of locational contingency reserves on the IEEE RTS96 system and compared the results with the conventional deterministic method. We found that assigning locational spinning reserves can guarantee an N-1 secure dispatch accounting for transmission congestion at a reasonable extra cost. The simulations also showed little value of allocating downward reserves but sizable operating savings from co-optimizing locational nonspinning reserves. Overall, the results indicate the computational tractability of the proposed method. Part II presents a distributed generation scheduling model to optimally allocate energy and spinning reserves among competing generators in a day-ahead market. The model is based on the coordination between individual generators and a market entity. The proposed method uses forecasting, augmented pricing and locational signals to induce efficient commitment of generators based on firm posted prices. It is price-based but does not rely on multiple iterations, minimizes information exchange and simplifies the market clearing process. Simulations of the distributed method performed on a six-bus test system showed that, using an appropriate set of prices, it is possible to emulate the results of a conventional centralized solution, without need of providing make-whole payments to generators. Likewise, they showed that the distributed method can accommodate transactions with different products and complex security constraints.
152

TRANSFER AV ÖPPNA FÄRDIGHETER I HIGH-COMMITMENT CALL-CENTERFÖRETAG

Kårebrand, Charlotte, Forsberg, Sandra January 2013 (has links)
High-commitment call-centers kännetecknas av investeringar i HR-praktiker såsom utbildning, vilka kräver transfer till arbetet för att generera avkastning på investeringen. Studien ämnade undersöka hur demografiska profiler relaterar till transfereffekter, self-efficacy och prestation. Den ämnade även undersöka vikten av antal utbildningstillfällen för self-efficacy och prestation samt faktorer som hindrar/faciliterar transfer. En multi-methods sequential explanatory design användes, där två studier genom-fördes på ett svenskt call-center som utförde en utbildningsinsats. I studie 1 samlades data in med en enkät (n = 51) och i studie 2 genomfördes intervjuer (n = 6). I studie 1 identifierades tre kluster med skilda demo-grafiska bakgrunder, bl.a. ålder och utbildningsnivå. En signifikant skillnad i transfer återfanns dem emellan. Neutral transfer återfanns och self-efficacy var högst hos deltagare som slutfört utbildningen. I studie 2 framkom att det upplevdes viktigt att utbildningens nytta var tydlig och att ett neutralt transferklimat rådde. Studierna antyder att hänsyn bör tas till det övergripande transfersystemet tillsammans med individen för att bäst facilitera transfer.
153

The relationship between career anchors, organisational commitment and turnover intention

Clinton-Baker, Michelle 22 January 2014 (has links)
The primary objectives of the study were as follows: (1) to explore the relationship between career anchors (as measured by the Career Orientations Inventory), organisational commitment (as measured by the Organisational Commitment Questionnaire) and turnover intention (as measured by a three-item questionnaire, developed by Mobley, Horner, and Hollingsworth, 1978); and (2) to determine whether employees from different gender, race, employment positions and age groups differ significantly in their career anchors, organisational commitment and turnover intention. A quantitative survey was conducted on a non-probability sample of 343 employed adults at managerial and general staff levels in the South African retail sector. The results of this study suggest that there was a significant but weak relationship between employees‟ career anchors and their organisational commitment. Career anchors were also found to be significantly related to organisational commitment and turnover intention; with entrepreneurial creativity, lifestyle and service/dedication to a cause career anchors being the best predictors of these two variables. The relationship between organisational commitment and turnover intention was significant and negative, with affectively and normatively committed participants being more likely to remain with the organisation (i.e. having lower turnover intentions). In addition, the findings indicate that although gender has no relationship with turnover intention, race, employment position and age do. African, general staff and 30 years and younger participants indicated higher intentions to leave the organisation. / Industrial & Organisational Psychology / M. Comm. (Industrial and Organisational Psychology)
154

A compositional framework for determining pattern applicability

Hakeem, Hossam Hassan January 2010 (has links)
The notion of ‘pattern’ originates in the work of Christopher Alexander and, in recent years, patterns have become a popular part of software development. A pattern is defined as a ‘three-part rule’: a relationship between a given context, a recurring system of forces peculiar to that context, and a specific spatial configuration that permits resolution of these forces. In essence, the ‘context’ of a pattern is the whole system under construction and its state in the construction process at the point at which the pattern is being applied. The nature of the context, therefore, changes at every step of the process and this has significant implications for how patterns should be used. Specifically, applying each pattern changes the context by changing the state of the system under construction and creates both a new design problem and a new context for the next pattern to be applied. The next picked pattern must have a certain criteria in order for it to be applied successfully and this is will be determined by the characteristics of the new context just created. The issue of composing pattern sequences is therefore more temporal than it is static and structural (as provided currently via pattern maps). The decision as to which one to use is temporally constrained in the sense that the choice is made only at a particular point in the construction process of some specific system, and may well be determined, or at least further constrained, by the current state of that system. The fundamental research question that is addressed here is: how is this dynamically changing context to be presented to guide pattern applications? In this thesis, a framework is presented to provide a systematic analysis of composition of pattern applications in terms of the properties of their context. Such an approach will reveal the ordering of patterns in space and time dimensions. Examples of composition of pattern applications include: - One pattern contains or generalises another smaller-scale pattern (this will be called in thesis refinement); - Two patterns are complementary, i.e., one pattern needs the other to be applied before (Sequential Order); - Two patterns solve different problems that overlap and coexist on the same level (Parallel Order); - Two patterns solve the same problem in alternative, but equally valid ways (Choice in Order). At the design phase, the framework provides mechanisms for analysing the choice of composition to ensure the correctness of a design or to compare between two different designs or to modify an existing design. This framework describes a pattern's context via a pair of constraints, known as Assumption and Commitment. In general, the Assumption is a constraint placed on the context and the Commitment is what the solution provided by the pattern commits to after the pattern's application. In addition, the thesis provides a set of composition rules that can be applied to aid in the analysis of the application of pattern sequences. The approach is domain independent as it does not depend on the nature of the catalogue from which the patterns originate. The work has been evaluated using various existing patterns from Ian Graham’s web usability (WU) pattern bank and the User Interface (UI) patterns of Welie.
155

Executive expectation in the internationalization process of banks : The study of two Swedish banks foreign activities

Hadjikhani, Annoch Isa January 2016 (has links)
Since the late 1980s, deregulation of the banking sector has opened new avenues for the internationalization of banks. There are, however, few studies on the internationalization of banks – particularly Swedish banks. The purpose of this thesis is to deepen our knowledge of bank’s internationalization process by studying how the executive function’s expectation of market conditions influences internationalization patterns. This thesis makes an empirical contribution by describing how the Swedish banks Svenska Handelsbanken AB and Swedbank AB have internationalized during the period 1995-2014. The empirical evidence comprises all of the two banks’ activities in foreign markets and the qualitative cases describing this process have been constructed using archival data (newspaper articles, press releases, and reports) complemented with interviews. Beside the empirical contribution the thesis makes a theoretical contribution to internationalization theory and more specifically to Johanson and Vahlne’s (1977) internationalization process model. While Johanson and Vahlne’s model does have a strong explanatory value, it does not fully explain its mechanisms (Andersen, 1993; Leonidou & Katsikeas, 1996) and only firm’s internationalizing incrementally (Liesch et al., 2002). For explanation of both incremental and non-incremental behaviors this thesis provides a proposed view of bank’s internationalization where the concept of executive expectation is developed as a mediating variable in Johanson and Vahlne’s internationalization process model. To this end, executive expectation is described as the driving and hindering force in bank’s internationalization process influenced by exogenous and endogenous changes.
156

The experiences of therapists and bereaved clients of using an acceptance and commitment therapy approach to grief

Walker, Karen Ann January 2013 (has links)
Background and Aims: Whilst bereavement is a generally a normal process of adjustment, for some individuals the outcome can be more serious. Current bereavement research has produced inconclusive results to date and been criticised on many levels. A gap has been identified between research and the practice of bereavement therapy.The aim of this thesis is to examine a relatively new and under researched approach to the treatment of grief, namely the use of Acceptance and Commitment Therapy (ACT). It is proposed that this approach could provide an empirically sound model on which therapists could base their interventions. Method: Firstly a conceptual review examines the key components of ACT and their applicability to grief work. Secondly, a qualitative piece of research uses interpretative phenomenological analysis to explore the lived experiences of both therapists and clients who have used the approach. Results: The conceptual review finds a good degree of fit between the components of the ACT therapeutic model and the needs and aims of bereavement work. The qualitative study provides preliminary support for the application of the model in the treatment of grief, indicating positive experiences for both therapists and clients particularly in its valuing of the individual nature of grief, its ability to put suffering into a positive context and its strength in dealing with emotional and thought related issues. Implications: The thesis provides a theoretical underpinning and an exploration of practice in the treatment of grief which may be useful for therapists considering a new approach to grief work or those developing services for the bereaved.
157

Giving It the Old College Try: Understanding Degree Commitment among Division I FBS NFL Aspirants

Martinez, Guadalupe Federico January 2012 (has links)
Building on sociological studies regarding college choice and persistence, this qualitative study investigates the college and post college experiences of 15 current students with NFL aspirations and 13 former students who held NFL aspirations, all from Division I Football Bowl Series (FBS) programs. A phenomenological design is implemented to explore participants' lived experiences, and awareness of their educational and occupational options. Deil-Amen and Tevis' (2010) Circumscribed Agency frames this study and provides a lens for examining the college choice and departure process. The role of the student exerting agency as circumscribed by context, habitus, and self-efficacy is emphasized with self-perceptions being essential in the process of enacting individual behavior and decisions. Perna's (2006) conceptual college choice model is made up of four contextual layers and is used to further explain students' college choice behaviors. Findings are consistent with Bowen and Schulman (2001) in that students' college decisions are driven by their athletic pursuits. This study also addresses persistence for this group of students. Tinto's (1993) theory on departure is used as a platform from which to examine commitment and social integration. Traditionally, degree commitment has been measured as strong or which severely limits our understanding of persistence. Findings reveal degree commitment to be fluid and contingent upon perceived occupational options, health status, and year in college. The majority of current students express commitment to degree attainment as a priority. However, further investigation reveals degree commitment to exist without a specific time frame set by students. This adds a time dimension to our understanding of degree commitment. This study further extends Tinto's concept of commitment with evidence of two competing goal commitments: degree and occupational. Decisions to leave college early for the NFL are driven by participants' self-perception of their athletic abilities despite where they are on the team's talent roster. This decision is further shaped by their college community integration consisting of teammates, coaches, and the NFL. Former students who stopped out of college reveal unanticipated challenges with re-entry into college. However, in contemplating a return to complete their bachelor’s degree, stop outs articulate a renewed sense of energy and degree commitment given a change in their occupational trajectory and situated context.
158

A multidimensional approach to the study of organisational commitment : empirical evidence from a Malaysian context

Nik Abdul Rahman, Nik Mutasim January 2001 (has links)
No description available.
159

Creating a commitment continuum through the development of shared values in the banking sector / André Johan van Rooyen

Van Rooyen, André Johan January 2013 (has links)
Research is undertaken into the correlation between shared values and organisational performance. The issue of commitment continuity as a pre-requisite for improved financial and operational performance is investigated in detail. Emphasis is placed on the theories and nature of growth and sustainability; sustainable change within the organisation; and employee commitment emphasising aligned commitment as well as elements constituting the aligned commitment equation. The role of management has been identified as a determining factor that underlies the commitment of employees in an organisation. It is found that organisations should change their definition of “growth” from actual profits to the management of talent within the organisation in order to realise the benefits of sustained commitment. Literature studies into concepts such as shared values and shared vision and how these concepts can be inculcated into organisations through the implementation of effective change management processes is done. Should these concepts be universally accepted throughout the organisation, it will lead to organisational commitment which will eventually evolve into a commitment continuum. The presence of a commitment continuum will inevitably lead to the achievement of sustainable growth and a high performance culture within the organisation. To ensure the process is credible it should at all times adhere to both the spirit and letter of prevailing legislation and regulation as well as accepted norms of good practice. The impact that the concepts such as Knowledge, Information, Empowerment, Performance Strengthening and Shared Values have on the attainment of aligned commitment was examined. Also discussed were the comparisons between the South African and Namibian operations of the financial organisation. This research study was approached from a human perspective and should contribute towards the attainment of a commitment continuum within the organisation, through the aforementioned concept, with specific focus on Shared Values. The study includes both literature and empirical research. The study covers a numbers of disciplines that, when seen together, provides better understanding as how these constructs interact with one another in the attainment of sustained commitment and the presence of a commitment continuum. This, in turn, will lead to improved financial performance on the part of the organisation. The study has practical value in the sense that the newly adapted questionnaire and equation framework should enable organisations to measure the degree to which the influential constructs contributing to aligned commitment, already exist. The results show that a commitment continuum can be established in the financial services sector through aligned organisational commitment, the introduction and development of a shared values system and the establishment and acceptance of a shared vision. Coupled with organisational commitment, this will furthermore lead to growth and sustainability and a high performance culture being attained within the organisation. / MBA, North-West University, Potchefstroom Campus, 2014
160

Test-retest reliability and further validity of the cognitive fusion questionnaire

Campbell, Lindsey January 2010 (has links)
Introduction Acceptance and Commitment Therapy (ACT) has developed from traditional behavioural theory and seeks to reduce experiential avoidance and increase psychological flexibility. It is argued to be distinct from cognitive therapy and has been used to treat a variety of mental health problems in addition to chronic pain. ACT is linked to Relational Frame Theory and the research developments associated with this. One central process of ACT is termed ‘cognitive defusion’ and this process is used to encourage individuals to become less identified with the content of their cognitions. It is important to measure the extent to which individuals become ‘fused’ with their cognitions and a Cognitive Fusion Questionnaire (CFQ) has been developed to do this. The current studies build upon earlier research by subjecting the CFQ to further reliability and validity testing and assessment of its factor structure. Method A community sample was used throughout. The majority of participants took part online, however, some participants completed paper copies of the questionnaires. Study one had a sample of 47 and focused on construct validity of the CFQ where participants completed this measure and also measures of similar and distinct constructs. The other measures included a mindfulness questionnaire, a measure of experiential avoidance and a social desirability questionnaire. Study two concerned the test-retest reliability of the CFQ. There were 82 participants in this study who completed the CFQ on two occasions, one month apart. In this study, participants also completed a measure of anxiety and depression symptoms. Study three had 144 participants and assessed the factor structure of the CFQ. Results Results from study one indicate that the CFQ negatively correlates with a measure of mindfulness and positively correlates with a measure of experiential avoidance. This study also found that the CFQ has no relationship with a measure of conscious attempts to appear more desirable. Results from study two show that there is a strong positive correlation between scores on the CFQ at testing time one and testing time two. The CFQ was also found to correlate positively with a measure of anxiety and depression symptoms and to mediate the relationship between anxiety scores at testing time one and testing time two. Confirmatory factor analysis was used in study three to assess the factor structure of the CFQ and found a two factor model was the best fit for the data. Discussion The results are considered in relation to relevant research. Limitations of the current studies are assessed and possibilities for future research discussed. In particular, cognitive fusion is discussed in relation to anxiety and depression symptoms. The similarities between the CFQ and a measure of experiential avoidance are discussed and the different aspects of measurement are reflected upon.

Page generated in 0.0725 seconds