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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.
131

Demand Learning in Two Operations Models

Han, Yunru January 2016 (has links)
The rapid advance of information technologies largely facilitated firms' data-driven decision making. Particularly, in operations management practices, firms could continuously collect information to refine their demand knowledge, and integrate this process into their relevant operational decisions, e.g. pricing, inventory, and market entry, known as demand learning. Demand learning in complex business systems is often tangled with complex strategic interactions, thus requiring a deep understanding of how it affects the strategic relationship among players in various business setups. This thesis aims to contribute to the demand-learning literature by studying the strategic interactions in two different business relationships, one vertical and the other horizontal. First, I consider the interactions between a retailer and a supplier in a supply chain subject to demand censorship (i.e. unobservable lost sales) when the retailer is engaging in demand learning through dynamic inventory experimentation. I study the supplier's optimal wholesale prices when the retailer is in three different situations, and find that the retailer and the supply chain may actually benefit from either myopia or censorship in contrast to the existing results, due to the supplier's different collaborative or exploitative responses to the retailer's "willingness to learn". I also identify that, with demand censorship, the collaborative behavior between the players for information acquisition may improve the system's performance. Second, I study an online retail platform's learning process and entry policies as well as the independent seller's pricing distortion behavior to slow down this process, motivated by Amazon.com's unique dual role as both a marketplace and a merchant that allows it to use the transaction data generated by its third-party sellers to decide if to sell the same product itself. I developed a Bayesian statistical model for the platform's demand learning, proposed two types of heuristic entry policies for the platform owner. The model predicts a pattern of price distortion, and describes the product offering choices made by the independent seller. These could potentially serve as testable results for empirical studies.
132

Joint determination of sales lever and inventory control with uncertain demand. / CUHK electronic theses & dissertations collection / ProQuest dissertations and theses

January 2006 (has links)
Assuming that all unmet demand is fully lost, we begin our study by confining the sales lever to be price only, that is, z = p , and ignoring the cost for executing the sales lever. Given a stationary (s, S, p) policy, we find that the profit function for the lost-sales case exhibits the same structure as the one for the backlogging case. We further show that the relaxed assumption on the news-vendor type profit function can also be satisfied by a broad class of demand function. We can therefore extend the optimizing algorithm and the optimality analysis developed earlier to the lost-sales case. We further demonstrate that the results can be extended to the general sales lever decisions. / Assuming that unmet demand is fully backlogged, a newsvendor-type profit function which is defined as the resulting expected one-period profit with sales lever being optimized for every inventory level, fails to be unimodal. By assuming the newsvendor-type profit function to have a finite number of local maxima, we develop an efficient algorithm for finding the optimal ( s, S, z) policy with the long-run average profit derived by the renewal theory. We further identify the conditions under which the (s, S, z) policy is globally optimal. / Issues on the interfaces between operations management and marketing research have attracted much attention recently. The developments integrating marketing decisions into inventory management are not only of academic interest, but also of practical importance. With uncertain demand, this research studies the joint determination of inventory and sales lever decisions such as price, incentives to salesforce, and short-term promotions, or a combination of them. / We consider a single-item, periodic-review system with the objective of maximizing the long-run average profit over an infinite planning horizon. Demand in a period is a non-negative, discrete random variable with its distribution dependent on the sales lever chosen for the period. A replenishment order can be placed at the beginning of a period incurring both fixed and variable ordering costs. The sales lever is determined jointly, and its execution may incur possible cost, for example, promotion cost. For such a model, we take particular interest in a so-called (s, S, z) policy, which operates as follows: whenever the inventory level falls to or below s, an order is placed to bring it up to S; when the inventory level is above s, no order is issued; the choice of sales lever z depends on the inventory level. / We finally conduct an extensive numerical study for both the backlogging and lost-sales cases. We compare the benefits of the dynamic sales lever strategy with those of the semi-dynamic as well as the static sales lever strategy, and find that the profit gains are significant. By sensitivity analysis, we bring out the impact of cost parameters on the optimal solutions. / Wei Ying. / "December 2006." / Adviser: Youhua Frank Chen. / Source: Dissertation Abstracts International, Volume: 68-09, Section: A, page: 3961. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 125-131). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest dissertations and theses, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307.
133

The production of skills for the agricultural sector in Tanzania : the alignment of technical, vocational education and training with the demand for workforce skills and knowledge for rice production

Takei, Keiko January 2016 (has links)
The general objective of this study is to identify skills required by employers relevant to the agricultural sector especially in cash crop rice farming and to explore how to increase the contribution of new entrants to the labour market leading to increased production, socio-economic development and the reduction of income-poverty in Tanzania. Productivity gains in the agriculture sector have been modest and have had a limited effect on economic growth in Tanzania. Although the country has considerable agricultural potential, making the most of this depends on the availability of a labour force that has the skills to support a shift to greater productivity. This study profiles, analyses and examines the reality of skills provision and the emerging opportunities to find out how skills development and employability should be improved. The research questions focus on (i) identifying the existing skills gaps between employers' needs and employees' capabilities; (ii) identifying the skills which TVET programs impart to enhance performance in the agriculture subsector; and (iii) identifying the skills required by employers and analysing the employability of TVET graduates entering work in the agricultural sector, especially for paddy production. The study concludes by outlining policy implications for improving TVET programs for workforce development. Among the key research findings was the identification of the high degree of irrelevance of most TVET courses for the targeted labour market as overall 89 % of employers claim that the skills possessed by graduates were not applicable to their intended jobs. Moreover, there is a gap in perception between employers and employees about the value of their training. Serious concerns need to be addressed. This can be done by creating an effective system of knowledge dissemination and training building on the current cascade training system involving both the TVET institutions and the visitation of extension workers in the field responsible for enhancing the transfer of modern farming practices. Findings also indicate that very few TVET graduates who enter the agriculture sector have actually studied agriculture, and only seven percent out of the entire TVET graduating cohort have studied the agricultural track. These research findings, drawn largely from a case study analysis as well as analysis of secondary sources, were formed during my professional experience working in the TVET sub-sector in Tanzania. The findings lead to the conclusion that the nature and structure of the curriculum as well as the teaching methodology mean the skills of the TVET graduates are inadequate to meet the demand from the labour market, especially in the paddy production sector. In addition, the study findings lead to a number of critical policy options to reduce skills gaps by refining the curriculum and pedagogy to ensure it is more demand driven and by ensuring that a mechanism is created linking supply and demand. Critical policy options include the need for a clearer and more systemic occupational analysis of the skills needed in paddy production -- such as the analysis provided in the Developing A Curriculum (DACUM) approach in order to ensure that the TVET curriculum is in alignment with the demanded occupational skills. To enhance the scientific and technological foundation of TVET, a strong focus will be required on high-order literacy and numeracy skills. The study also suggests that to establish a “knock-on effect”, youth who obtain skills from TVET institutions also need to be provided with appropriate leadership training during their TVET programs in preparation for disseminating knowledge and skills to other farmers in the field and leading change in agricultural practice. The training system needs to be more closely linked with employers and work places where knowledge and skill can be utilised.
134

Migration and integration in borderless village : social capital among Indonesian migrant workers in South Korea

Park, Kwangwoo January 2014 (has links)
Existing research (Guarnizo et al. 2003; Portes, 2001; Cohen and Sirkeci, 2005) has endeavoured to clarify the relationship between migrants' transnational activities and their integration into the host society. Although there are both positive and negative perspectives on this relationship, it remains unclear whether migrants' transnational activities are likely to help or hinder their integration into the host society (Vertovec, 2009). This thesis uses the lens of social capital and diaspora identity to shed light on the relationship between Indonesian migrants' transnational activities and their integration in a multi-ethnic town in South Korea. The influx of migrants from various countries has led to the creation of what is called ‘Borderless Village', where people have opportunities to build intercultural connections beyond their national group. Based on ethnographic fieldwork with a group of Indonesian migrants, which themselves show social disjunctions in terms of region of origin, language, religious belief and cultural practices, this thesis examines the integration patterns of Indonesian immigrant groups in this town. In terms of whether transnational activities help or hinder integration in South Korea, I argue that both realities co-exist, and that the status of Wongok-Dong as a migrant enclave and the internally divided nature of the Indonesian migrant group itself are key factors in this regard. Indonesian migrants achieve integration among themselves by performing economic and socio-cultural transnational activities, thereby transcending divisions within the group. Although there are differences in terms of their capacity to conduct transnational activities that are shaped by each Indonesian immigrants' different types of social capital, they are able perform transnational activities through creating and utilising ‘hidden social capital'. This is generated when Indonesian migrants strategically reveal one of their identities, such as Indonesian, Muslim or other positions, rather than emphasising their regional origin in Indonesia to achieve their objectives such as pursuing economic profits, saving face and maintaining livelihood. Through mobilising these additional identities, most Indonesians can access resources that enable them to perform transnational activities – making international phone calls, occupying cultural spaces, participating in national celebrations – beyond their regional affiliations. In this regard, Indonesian migrants integrate into Wongok-Dong by performing transnational activities due to the features of the town as a migrant enclave. However, they are isolated from mainstream Korean society, as they only achieve integration into the multiethnic space of Wongok-Dong. Thus, this research adds crucial dimensions to theories of the relationship between migrants' transnational activities and integration into their host society through redefining both the features of the diaspora group and the role of social capital.
135

Matching Spatially Diversified Suppliers with Random Demands

Liu, Zhe . January 2019 (has links)
A fundamental challenge in operations management is to dynamically match spatially diversified supply sources with random demand units. This dissertation tackles this challenge in two major areas: in supply chain management, a company procures from multiple, geographically differentiated suppliers to service stochastic demands based on dynamically evolving inventory conditions; in revenue management of ride-hailing systems, a platform uses operational and pricing levers to match strategic drivers with random, location and time-varying ride requests over geographically dispersed networks. The first part of this dissertation is devoted to finding the optimal procurement and inventory management strategies for a company facing two potential suppliers differentiated by their lead times, costs and capacities. We synthesize and generalize the existing literature by addressing a general model with the simultaneous presence of (a) orders subject to capacity limits, (b) fixed costs associated with inventory adjustments, and (c) possible salvage opportunities that enable bilateral adjustments of the inventory, both for finite and infinite horizon periodic review models. By identifying a novel, generalized convexity property, termed (C1K1, C2K2)-convexity, we are able to characterize the optimal single-source procurement strategy under the simultaneous treatment of all three complications above, which has remained an open challenge in stochastic inventory theory literature. To our knowledge, we recover almost all existing structural results as special cases of a unified analysis. We then generalize our results to dual-source settings and derive optimal policies under specific lead time restrictions. Based on these exact optimality results, we develop various heuristics and bounds to address settings with fully general lead times. The second part of this dissertation focuses on a ride-hailing platform's optimal control facing two major challenges: (a) significant demand imbalances across the network, and (b) stochastic demand shocks at hotspot locations. Towards the first major challenge, which is evidenced by our analysis of New York City taxi trip data, the dissertation shows how the platform's operational controls--including demand-side admission control and supply-side empty car repositioning--can improve system performance significantly. Counterintuitively, it is shown that the platform can improve the overall value through strategic rejection of demand in locations with ample supply capacity (driver queue). Responding to the second challenge, a demand shock of uncertain duration, we show how the platform can resort to surge pricing and dynamic spatial matching jointly, to enhance profits in an incentive compatible way for the drivers. Our results provide distinctive insights on the interplay among the relevant timescales of different phenomena, including rider patience, demand shock duration and drivers' traffic delay to the hotspot, and their impact on optimal platform operations.
136

Supply and Demand of Elementary School Teachers in Utah

Jackson, Arthur D. 01 May 1949 (has links)
During the years of World War II the faculties of the public schools in Utah, as well as in the rest of the nation, were depleted to a serious extent, and enrollment in teacher training institutions throughout the country decreased. Because of this condition the State Department of Education in Utah as well as in other states was forced to issue letters of authorization to teachers who could not meet standard certification requirements in order to staff the schools. Many of these teachers are still teaching today. The purpose of this study is to obtain information regarding the supply of and demand for elementary teachers in the state of Utah for the period 1946-1949, and to predict the demand for teachers to 1955-56. an attempt will be made to answer the following questions: Did the state gain ground by having an increased percentage of qualified teachers during the three year period (1946-1949) assuming that the number of teaching positions remaind the same? If gains were made, how long will it take to equalize the situation? Assuming present practices will not equalize supply and demand by 1956, how much of an increase in supply will be needed by 1956? From evidences that we have on changing demand from increased population, increased educational services, e.g. kindergarten and decrease in class size, how much of an increase in suppy will be needed by 1956? Only the supply of and demand for teachers of the elementary school will be dealt with in this study. The supply of and demand for secondary teachers is treated in another study that is being done in conjuction with this one.
137

A simulation model for quantifying and reducing the bullwhip effect

Wangphanich, Pilada, Mechanical & Manufacturing Engineering, Faculty of Engineering, UNSW January 2008 (has links)
Over the past of decade, the bullwhip effect has increasingly become a popular topic for researchers and practitioners in the area of supply chain management since it negatively influences cost, inventory, reliability and other important business processes in supply chain agents. Although there are many remedies for the bullwhip effect summarised in existing literature, it still occurs in several industries. This is partly because it is difficult to apply the results from existing research which analyse the bullwhip effect mainly in a simple supply chain. In addition, several tools and methodologies developed are used for analysing the bullwhip effect in a simple supply chain with several constraints. Therefore, this research aims to develop a unique simulation approach based on system dynamics modelling and Adaptive Network Based Fuzzy Inference System (ANFIS) for quantifying and reducing the bullwhip effect in a multi-product, multi-stage supply chain. System dynamics modelling which is a powerful simulation approach for studying and managing complex feedback system was selected as a main tool in this research. In addition, ANFIS was implemented in system dynamics modelling in order to increase the reliability of a system dynamics model for modelling soft variables. The proposed model covers variables influencing the bullwhip effect which are the structure of supply chain network, supply chain contributions and supply chain performances. As a result, a two layer simulation with three generic models was developed. The flexibility of this proposed model is the ability to model various types of ordering policies which are basic inventory policies, Material requirement planning (MRP) system and Just in time (JIT) approach. Three actual manufacturing supply chains were used as case studies to validate and demonstrate the flexibility of the model developed in this research. This model satisfactorily quantifies the bullwhip effect and the bullwhip effect levels identified in these case studies are significantly decreased by using the proposed simulation model. The successful results indicate that the model can be a useful alternative tool for supply chain managers to quantify and reduce the bullwhip effect in multi-product, multi-stage supply chains.
138

Using scenario planning to identify potential impacts of socio-demographic change on aspects of domestic tourism demand in Queensland in 2021

Glover, Petra Sabine Unknown Date (has links)
No description available.
139

On Risk Prediction

Lönnbark, Carl January 2009 (has links)
This thesis comprises four papers concerning risk prediction. Paper [I] suggests a nonlinear and multivariate time series model framework that enables the study of simultaneity in returns and in volatilities, as well as asymmetric effects arising from shocks. Using daily data 2000-2006 for the Baltic state stock exchanges and that of Moscow we find recursive structures with Riga directly depending in returns on Tallinn and Vilnius, and Tallinn on Vilnius. For volatilities both Riga and Vilnius depend on Tallinn. In addition, we find evidence of asymmetric effects of shocks arising in Moscow and in the Baltic states on both returns and volatilities. Paper [II] argues that the estimation error in Value at Risk predictors gives rise to underestimation of portfolio risk. A simple correction is proposed and in an empirical illustration it is found to be economically relevant. Paper [III] studies some approximation approaches to computing the Value at Risk and the Expected Shortfall for multiple period asset re- turns. Based on the result of a simulation experiment we conclude that among the approaches studied the one based on assuming a skewed t dis- tribution for the multiple period returns and that based on simulations were the best. We also found that the uncertainty due to the estimation error can be quite accurately estimated employing the delta method. In an empirical illustration we computed five day Value at Risk's for the S&P 500 index. The approaches performed about equally well. Paper [IV] argues that the practise used in the valuation of the port- folio is important for the calculation of the Value at Risk. In particular, when liquidating a large portfolio the seller may not face horizontal de- mandcurves. We propose a partially new approach for incorporating this fact in the Value at Risk and in an empirical illustration we compare it to a competing approach. We find substantial differences.
140

A Study on Management Strategy of Seafarer Officers for Vessel ¡V Taking the S Company as Example

Yeh, Jiin-Shin 30 July 2011 (has links)
Officers played an important role on the vessel, including instrument operations, navigational safety, and cargo handling. Therefore, all the shipping companies desired to recruit outstanding people to fit the business strategies and enhance organizational performance. In 2005, according to BIMCO (Baltic International Maritime Council) / ISF (International Shipping Federation), there is the imbalance of the demand and supply. Shipping industry acts as an important role for Taiwan¡¦s economic development in past decades. An effective shipping development policy must contain those projects of officers¡¦ training, employment, and welfare scheme. All these measures have to be adopted through legislative efforts which will rely on the efforts of government and private sectors. In view of Taiwan¡¦s officers¡¦ policy has faced some challenges and needs to be reviewed in order to provide solutions to the difficulties. In this way, this study focuses on those officers of S company by qualitative interview, knowing the imbalance of the demand and supply and provides strategies recommendations. The results showed that small and medium carriers operate this industry with limited funds and lacking of complete structure. In this situation, those officers¡¦ welfare need to be enforced. The Government should develop complete and effective policies. In this way, we can build up a promising marine industry. In this case, we can find out that the company in the whole welfare system is worse than other companies. The policy-related issues including the flag of convenience problem, national mechanism for the overall training system, and the imbalance of demand and supply¡Ketc. We expect that the industry, government, academia provides an effective and sustainable policies to enhance and develop the shipping business. Keywords: Shipping development policy, officer¡¦s policy, imbalance of officer¡¦s supply and demand

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