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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.
51

Factors influencing learner performance in the economic and management sciences in the Ilembe district

Siyaya, Mlindeni Celinhlalo, Ndlovu, B.B., Gamede, B.T. January 2019 (has links)
Submitted to the faculty of education in fulfillment of the requirements for the Degree of Master of Education in the Department of Social Science Education at the University of Zululand, 2019 / This thesis explores “Factors Influencing Learner Performance in the Economic and Management Sciences in the iLembe District”. This study has used a mixed methodology, in Mandeni ward in KwaZulu-Natal. This district has four hundred and forty-two (442) schools. The district is divided into five (5) wards. One of those wards is Mandeni Ward, which has thirty-four (34) schools. The data analysing technique that was used is thematic analysis. The greatly publicised poor matric results in South Africa point to many systemic challenges in the education system. The system of education in South Africa requires teachers who are highly skilled to impart knowledge to learners. The historic curriculum paradigm shifts in the South African education system brought numerous changes. In the process of these curriculum changes, there is no evidence that suggests teachers’ involvement. For example, the introduction of Economic and Management Sciences (EMS) as a learning area brought about challenges to educators as EMS became a combination of three learning areas in one. The challenge of identifying a competent teacher in the three-layered EMS was exacerbated by the introduction of external examinations in grade seven, during the 2014 academic year. This research has attempted to investigate the factors that exist for teachers and heads of department with regards to EMS. In this study, a range of questioning statements that render relevant information about the factors that may influence performance in EMS have been employed. Through the use of interviews, qualitative data were collected from grade seven to nine teachers, as well as heads of department. Another set of data was generated using questionnaires given to the same participants. The final set of data was obtained using document analysis: where mark schedules for grade seven were analysed with the aim of investigating learner performance. This study found that EMS is being taught by unqualified EMS teachers due to the shortage of qualified EMS teachers (Modise, 2014). The absence of qualified teachers negatively impacts on the educational objectives of the EMS learning area. The study also discovered that the lack of exposure to commercial subjects in high school does dampen the confidence and the enthusiasm of the teacher and hamper their eagerness to stand in front of the learners to teach EMS. The insufficient time allocated for EMS and EMS workshops also negatively impacts on the objectives and outcomes for this subject. The lack of parental involvement in EMS related discussions also hampers the educational objectives of the EMS learning space. There are recommendations that suggest that there is a need to urgently revisit the manner in which EMS teachers are trained. The provision of EMS related resources has to be drastically improved if vi the stakeholders desire to witness identifiable and life-changing results. There is dire need to immediately review the EMS curriculum policy.
52

Optimal Shipping Decisions in an Airfreight Forwarding Network

Li, Zichao January 2012 (has links)
This thesis explores three consolidation problems derived from the daily operations of major international airfreight forwarders. First, we study the freight forwarder's unsplittable shipment planning problem in an airfreight forwarding network where a set of cargo shipments have to be transported to given destinations. We provide mixed integer programming formulations that use piecewise-linear cargo rates and account for volume and weight constraints, flight departure/arrival times, as well as shipment-ready times. After exploring the solution of such models using CPLEX, we devise two solution methodologies to handle large problem sizes. The first is based on Lagrangian relaxation, where the problems decompose into a set of knapsack problems and a set of network flow problems. The second is a local branching heuristic that combines branching ideas and local search. The two approaches show promising results in providing good quality heuristic solutions within reasonable computational times, for difficult and large shipment consolidation problems. Second, we further explore the freight forwarder's shipment planning problem with a different type of discount structure - the system-wide discount. The forwarder's cost associated with one flight depends not only on the quantity of freight assigned to that flight, but also on the total freight assigned to other flights operated by the same carrier. We propose a multi-commodity flow formulation that takes shipment volume and over-declaration into account, and solve it through a Lagrangian relaxation approach. We also model the "double-discount" scheme that incorporates both the common flight-leg discount (the one used in the unsplittable shipment problem) and the system-wide discount offered by cargo airlines. Finally, we focus on palletized loading using unit loading devices (ULDs) with pivots, which is different from what we assumed in the previous two research problems. In the international air cargo business, shipments are usually consolidated into containers; those are the ULDs. A ULD is charged depending on whether the total weight exceeds a certain threshold, called the pivot weight. Shipments are charged the under-pivot rate up to the pivot weight. Additional weight is charged at the over-pivot rate. This scheme is adopted for safety reasons to avoid the ULD overloading. We propose three solution methodologies for the air-cargo consolidation problem under the pivot-weight (ACPW), namely: an exact solution approach based on branch-and-price, a best fit decreasing loading heuristic, and an extended local branching. We found superior computational performance with a combination of the multi-level variables and a relaxation-induced neighborhood search for local branching.
53

Auctions for Targeted Television Advertising

Zschocke, Mark Steven January 2008 (has links)
Television advertising is a billion-dollar industry in the United States. Currently, advertisers place their messages in television programs that are estimated to have a high proportion of their target demographic viewers. The advertising spots are usually purchased months in advance at set list prices or at negotiated prices. Technologies that can place advertisements at the cable box level, instead of the program level, will provide advertisers with the ability to target any demographic group directly and in real-time. This thesis explores the new decision-making required by this new technology and how the television advertisement space can be sold more effectively. In particular, it compares a list price system to a number of new auction models. The structure of the auctions for the new targeted television advertising system is unique and has not been previously studied in the literature. This thesis explores new auction models that can capture these unique features and lead to desirable results for the seller of the advertisement space. A simplified analytical model shows how these features impact advertisers’ bidding behavior and how a list price system compares to the auction models in the ability to raise revenue for the seller of the advertising space. These issues are then explored under various market settings with differing numbers of advertisers and value distributions that these advertisers have for the advertising space. Since sequential first price auctions have undesirable consequences such as strong price fluctuations, this work focuses on second price auctions. The Vickrey-Clarke-Groves (VCG) mechanism is customized for this problem by developing an optimization formulation that determines the best set of advertisers for a particular advertisement space. Because execution time may be an issue, other auction models are developed that lead to similar outcomes as the VCG mechanism but require less computational effort. This thesis provides guidance on when a list price system will lead to higher expected revenue than an auction model and vice versa in a targeted television advertising system. It also demonstrates why some of the standard auction models cannot be applied to this problem and what type of new models are required to lead to desirable advertising outcomes.
54

An Investigation of Basic Probability Operations Using AND and OR Operations

Tsoi, Joannie January 2007 (has links)
The purpose of this thesis was to observe people’s abilities to compute probability problems at a fundamental level. The problems in this study were presented in an abstract format to ensure non-ambiguity in its interpretation. The study was administered to university level students. The focus was to determine people’s ability to answer probability questions that combined the probabilities of two single events, using the most basic types of operations: AND and OR. The study found that while most people were able to compute AND type probability questions, most had trouble with OR operations. Of special interest was a switching strategy that was employed in computing OR operations as the probability of a single event varied. The study also revealed that statistically sophisticated people were able to adopt the mindset of people who were statistically naïve. Further research is required in order to develop a better framework in understanding people’s logical process of computing these basic probability questions as well as its application to our everyday lives.
55

Meaning Construction: Cognitive Processes of Conceptual Interaction

Ran, Bing January 2007 (has links)
This thesis proposes a theoretical framework explaining cognitive processes of meaning construction through conceptual interactions. It was noted that while the nine models or theories (Fuzzy Sets, Selective Modification model, Amalgam theory, Concept Specialization model, Composite Prototype Model, Dual-Process model, Constraint model, CARIN model, and Coherence Theory) in literature on conceptual combination offered insights on the problem of how people understand conceptual combinations, most of them assumed a schematic representation of our knowledge of concepts. However, it is possible that our minds represent knowledge in less structured ways and that schematic structure may not necessarily play a role in making sense of conceptual combinations. In this thesis, I attempted to make fewer assumptions about how knowledge is represented to explain the cognitive processes of conceptual combinations. I assume that concepts are related to other concepts, and knowledge can be represented by associations among concepts. Based on this assumption, the meaning of a conceptual combination is constructed through interactions between these associated concepts. It is proposed that the cognitive processes involved in meaning construction start from a distinction between different roles each component concept plays (head or modifier), and then a system of associations are activated contingently, prototypically, and efficiently with the goal of forming a cognitive field (analytically represented as a closed cycle) to connect head and modifier in a balanced way. The balanced system of concepts is strengthened further by reconciling remaining tensions in the field. Experimental results confirmed that component concepts in a combination activate associations contingently, and prototypicality and balance are major factors influencing whether an association will be activated by the combination to construct the meaning. Head / Modifier and Novelty were also studied as moderating variables. The experimental results indicated that head is a stronger moderator for association activation than modifier, and novelty was not found to be a significant moderator in association activation. Implications of these findings are discussed and future research is identified.
56

The Effect of Prior Commitment on Group Conflict in Judgemental Tasks

Kay, Min Beom 27 July 2007 (has links)
Previous research has identified commitment as one of the major contributing factors in group conflict and this study extends this line of research by considering group conflict as a result of varying members’ prior commitment for groups working on judgmental tasks with a unanimous decision rule. The goal of the group working on a judgmental task is to reach consensus but unanimous decision rule further complicates the decision making process as it requires every member to agree with group’s decision. Given this setting, prior commitment was expected to result in higher group conflict and this elevated level of conflict to have more negative affect on the group. With three judgmental cases formulated, subjects were divided into post-decision and pre-decision groups. In the post-decision groups, each subject was individually presented with each case first and committed to his own decision. With these prior commitments, subjects reached a unanimous decision through a group discussion. In the pre-decision groups, subjects reached a group decision without any prior commitment to their own decisions. Results showed signs of prior commitment contributing to group conflict. Furthermore, the post-experimental questionnaire showed that higher group conflict translates to more negative affects on the perceived performance, the extent to which members agree with the group’s decision, feeling toward other members and willingness to work with the same group.
57

Surface Partitioning for 3+2-axis Machining

Roman Flores, Armando January 2007 (has links)
Despite the inbuilt advantages offered by 5-axis machining, the manufacturing industry has not widely adopted this technology due to the high cost of machines and insufficient support from CAD/CAM systems. Companies are used to 3-axis machining and the operators are in many cases not yet ready for 5-axis machining in terms of training and programming. An effective solution for this 5 axis problem is a graduated migration through the use of 3+2-axis machining. The objective of this research is to develop and implement a machining technique that uses the simplicity of 3-axis tool positioning and the flexibility of 5-axis tool orientation, to machine complex surfaces. This technique, 3+2-axis machining, divides a surface into patches and then machines each patch using a fixed tool orientation. The tool orientation and section boundaries are determined to minimize the overall machining time. For each section the tool orientation is different but remains constant while machining this section. The number of patches selected for machining has a direct impact on the machining time. If the number of patches is small, the shape of the tool may vary greatly from that of the surface, which can result in smaller side-step distances. In contrast, a large number of patches leads to a better match between the tool and the workpiece, but it also leads to many re-orientations of the part as the tool moves between patches. Also, if the number of patches is large, the size of the patches will be reduced which will result in shorter tool passes that limit the tools ability to achieve the commanded feed rate. The optimum number of patches is a compromise between increasing the side step associated with large patches and the increase in time due to re-orientation of part and tool movement between patches. To find the optimal partition, a series of simulation tests are conducted to find the partition that would lead to the smallest machining time. This work presents the application of well known methods from Pattern Recognition and newly developed methods by the current author that were adapted for surface machining and boundary identification. This work also presents the methodology required to generate tool paths for 3+2-axis machining, which includes an explanation of the procedures required to determine an appropriate tool orientation, feed direction, tool path trajectory and tool parameters for patch-by-patch machining. These parameters are determined independently for each patch and aim at reducing the time required to machine a surface while maintaining the surface specifications. This work presents the surface partitioning scheme and the method of selecting optimum number of partitions along with actual machining experiments. Machining tests on four different surfaces were conducted to demonstrate the efficiency of the proposed technique. The results show that 3+2-axis machine reduced machining times over 3-axis ball nose machining and 5-axis machining using the “Sturz” method. Also, since the tool axis remains fixed during cutting, the tool offers constant feed rates and a better surface finish compared to simultaneous 5-axis.
58

Emergence and Influence of Expertise in Group Decision Making: A Judgmental Task

Tajeddin, Golnaz January 2007 (has links)
This thesis investigates the emergence and influence of expertise in group decision making while performing a judgmental task. Previous studies focused on intellective tasks or compared the group performance with the performance of the best individual in the group. In this study, performance feedbacks are provided to groups to help group members compare the individual performances and identify the expert. Laboratory experiments were conducted in which the task was to select a proverb that Canadians would like the most from the list of four proverbs from countries other than Canada. The four proverbs for each question were guaranteed to have equal selection probability based on the pretest survey. 18 four-person cooperative groups were asked to perform the task for eight iterations each. One member in each group was selected randomly to be the expert. Groups received performance feedbacks that reinforced the expert at the end of each iteration. The amount of information conveyed to each group regarding the expertise level of each group member was measured with a novel application of information analysis that captures the expert's gradual emergence. Experiment results supported the hypotheses of this study that (1) group members recognize the expert when working on a judgmental task with performance feedback and (2) while performing a judgmental task, the expert has more influence on the group decision making compared to others.
59

Auctions for Targeted Television Advertising

Zschocke, Mark Steven January 2008 (has links)
Television advertising is a billion-dollar industry in the United States. Currently, advertisers place their messages in television programs that are estimated to have a high proportion of their target demographic viewers. The advertising spots are usually purchased months in advance at set list prices or at negotiated prices. Technologies that can place advertisements at the cable box level, instead of the program level, will provide advertisers with the ability to target any demographic group directly and in real-time. This thesis explores the new decision-making required by this new technology and how the television advertisement space can be sold more effectively. In particular, it compares a list price system to a number of new auction models. The structure of the auctions for the new targeted television advertising system is unique and has not been previously studied in the literature. This thesis explores new auction models that can capture these unique features and lead to desirable results for the seller of the advertisement space. A simplified analytical model shows how these features impact advertisers’ bidding behavior and how a list price system compares to the auction models in the ability to raise revenue for the seller of the advertising space. These issues are then explored under various market settings with differing numbers of advertisers and value distributions that these advertisers have for the advertising space. Since sequential first price auctions have undesirable consequences such as strong price fluctuations, this work focuses on second price auctions. The Vickrey-Clarke-Groves (VCG) mechanism is customized for this problem by developing an optimization formulation that determines the best set of advertisers for a particular advertisement space. Because execution time may be an issue, other auction models are developed that lead to similar outcomes as the VCG mechanism but require less computational effort. This thesis provides guidance on when a list price system will lead to higher expected revenue than an auction model and vice versa in a targeted television advertising system. It also demonstrates why some of the standard auction models cannot be applied to this problem and what type of new models are required to lead to desirable advertising outcomes.
60

Trade-off between Innovation and Sustainability: Perceptions from Students from Developed and Developing Countries

Zhang, Yang January 2008 (has links)
This study investigated the human perception of certain social values to improve national well-being. It focused on the relative importance of two values, innovation and sustainability. Finally, it examined the possibility of a perceived trade-off between these two values by identifying whether a value change occurred among people from developed and developing countries under both constrained (forced-choice) and unconstrained (free-choice) rating conditions. The perceived importance of social values was measured in a survey using an eleven point rating scale. The perceived trade-off and the value change were identified by analyzing rating responses of the survey from test to retest. The analysis found that participants experienced a significant value change from test to retest and participants had different value preference depending on their country type, either developed or developing. This study consisted of two parts. The exploratory pilot study was conducted based on the Management Sciences Student Survey. This survey gathered information about the importance of selected social values from sixteen graduate students in the Department of Management Sciences at the University of Waterloo. The confirmatory main study was conducted using a web-based survey, Global Representative Value Change Survey. It collected information about the importance of the social values from close to three hundred students at the university at both test (Time One) and retest (Time Two). In this way, it enabled the researcher to identify a value change over time that was primarily attributed to a salience manipulation of innovation and sustainability trade-off. With a focus on the trade-off, the results revealed that all participants from developed and developing countries experienced a significant value change under the unconstrained condition, while very few significant value changes took place under the constrained condition. This study implies that people tend to maintain their value consistency and are not inclined to trade-off innovation for sustainability. If these values can co-exist in harmony and without compromise, people are prepared to give due consideration to sustainability, but not at the compromise to innovation. Implications are highlighted for educators, policy makers, and managers of technological innovation and change.

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