• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1801
  • 680
  • 675
  • 332
  • 237
  • 137
  • 94
  • 89
  • 75
  • 72
  • 47
  • 42
  • 42
  • 42
  • 42
  • Tagged with
  • 4948
  • 511
  • 448
  • 412
  • 389
  • 374
  • 337
  • 295
  • 276
  • 274
  • 269
  • 262
  • 258
  • 257
  • 246
  • 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.
81

Government Regulation in the Wireless Telecommunications Industry: The Impact of Wireless Number Portability

Pemberton, Anne January 2013 (has links)
Thesis advisor: Frank Gollop / By November 2003, wireless telecommunications operators were required by the FCC to have implemented wireless number portability. The FCC and the media claimed that this decrease in the cost of switching would force operators to react competitively by either decreasing prices or increasing the services offered at the same price to prevent customers from migrating to competitors. This paper empirically analyzes the effect that this regulation had on plan prices offered by the top four U.S. cellular operators over the period of Q2 2002 through Q2 2008, identifying whether they increased or decreased and by how much. This paper concludes that three out of the four nationwide carriers lowered prices in response to the implementation of wireless number portability. / Thesis (BA) — Boston College, 2013. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Economics Honors Program. / Discipline: College Honors Program. / Discipline: Economics.
82

The effects of competition on advertising incentives. / 競爭強度對廣告支出意欲的影響 / Jing zheng qiang du dui guang gao zhi chu yi yu de ying xiang

January 2012 (has links)
公司廣告支出的意欲如何受行業的競爭激烈程度影響?除了行業的集中度,競爭的激烈程度可以在多種不同的情況下改變,包括制度變遷等,從而影響一間公司在未來存在的可能性。此外,一間公司對於其未來的生存機會,以及未來利潤的預期,均會影響其廣告支出。本文旨在探討公司如何在不同的競爭程度下,作出廣告支出的決策。本文透過公司與消費者之間的信息不對稱的信號傳遞模型,提出一個闡釋競爭與廣告的簡單理論。 / How are advertising incentives affected by the level of competition? Apart from the concentration levels, the intensity of competition can be altered in many different ways, including institutional changes which affect a firm’s existence in the future. Also, advertising incentives are influenced by anticipated future profits and hence the firm’s chance of survival. This paper aims to investigate how advertising decisions are made under different levels of competition. It proposes a simple theory of competition and advertising, through a signaling model with information asymmetry between a firm and a consumer. / Detailed summary in vernacular field only. / Yuen, Shuk In Jacqueline. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 26-27). / Abstracts also in Chinese.
83

Identifying a common cause of the loser cell status in Drosophila melanogaster

Dinan, Michael Peter January 2019 (has links)
Cell competition is the process whereby less fit cells termed "losers" are selectively eliminated from a tissue by their fitter neighbors - or " winners." This sacrifice of aberrant cells is thought to have evolved at the advent of multicellularity to enforce cell co-operativity and ensure the fitness of the host organism. Accumulating evidence over the last 40 years has suggested key roles for cell competition during development, adult tissue homeostasis and at the onset and during the progression of diseases including cancer. However, if we are to exploit competition in the treatment of human pathologies and in tissue regeneration, we still have a lot to learn about the underlying mechanisms that ultimately instruct the elimination of loser cells. The main goal of this work was to identify the key molecular events that are responsible for initiating the loser status of Minute heterozygous cells. As many Minute mutations affect ribosomal genes, it has long been assumed that the loser status is closely linked to their associated slow growth phenotype, which occurs a consequence of reduced protein synthesis. Surprisingly, I have found that the loser status is independent of rates of translation. Instead, the activity of a single transcription factor, Nrf2, that typically co-ordinates an oxidative stress response, is sufficient to instruct the elimination of cells by their neighbors. Given the importance of Nrf2, I have sought to identify events occurring both upstream and downstream of the pathway in the loser context. Here, I have shown how multiple loser cell types are suffering from an underlying proteotoxic stress, as a result of an imbalance in proteostasis and their accumulation of toxic protein aggregates. In addition, I have developed a screening strategy to identify key molecules downstream of Nrf2 that could be involved in loser cell recognition. These findings not only provide new insights into the mechanisms of cell competition, but broaden the implications of the process to age-related diseases including those that result in neurodegeneration.
84

An action-based perspective of firm heterogeneity: source of competitive advantage. / CUHK electronic theses & dissertations collection / Digital dissertation consortium / ProQuest dissertations and theses

January 2002 (has links)
Drawing on the concepts of embeddedness, this study suggests that the forms and contents of network ties are external antecedents of the decision on competitive repertoires made by firms. The forms of network include institutional embeddedness, network centrality, social capital. Information simplicity is the content which has three measures---concentration, dominance, and range. The effects of internal antecedents, namely slack resources, experience and cognitive sunk cost of board of directors, are also examined. Results show that, in general, heterogeneity in competitive repertoire of a firm is positively associated with its forms of network ties. In the case of the content of network, the simpler is the information in concentration and dominance, the greater the heterogeneity. Interestingly, diversity in competitive repertoire of a firm is negatively associated with its institutionally embeddedness and information simplicity in range. / In the competitive dynamics line of research, the investigation of the antecedents of competitive repertoires is less developed. The findings on impacts of competitive actions on performance are not conclusive as well. This study aims to uncover both the internal and external antecedents that affect the firm's decisions on competitive repertoires. Drawing from previous studies in micro-competitive behaviours, a typology of four modes of competitive differentiation---specific action, deviation, diversity, and heterogeneity---is introduced. Then, this study investigates the effectiveness of these four different modes of differentiation in sustaining competitive advantage. The sample analysed in this study consists of firms from both banking and hotel industries. The causes and consequences of firm-level rivalry are examined over a period of six years. / Overall, this study provides new theoretical insight and empirical evidence regarding the relationship between the forms and contents of firm's external embeddedness and its competitive repertoires. In addition, the use of semi-annual time frame adds richness to existing methods of observing and measuring competitive actions in the study of micro-competitive behaviors. The results of this study also suggest that competitive repertoires, rather then single moves, play a key role in firm's ability to sustain competitive advantage. Finally, this study provides valuable guidelines in the appointment of board directors, particularly with respect to links between competitive repertoires and the directors' institutional and network embeddedness, social capital, and information possessed. / The examination of the effects of different modes of competitive differentiation on firm performance reveals that only diversity and heterogeneity in competitive repertoire are essential for superior performance and to outperform competitors. These findings have two implications. First, for superior performance, firm must differentiate itself from its competitors rather than being a follower. Second, such differentiation must have the competitive actions structured in a portfolio mode rather than separate and independent moves. / Yeung Ping Kwong. / "April 2002." / Adviser: Chung-Ming Lau. / Source: Dissertation Abstracts International, Volume: 63-05, Section: A, page: 1911. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (p. 171-187). / 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 dissertations and theses, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.
85

Multimarket Contact And Competitive Aggressiveness At The Marketing Mix Tactical Level

January 2015 (has links)
acase@tulane.edu / ABSTRACT Multimarket competition theory centers in interfirm competition, specifically when a set of firms have presence and face each other as competitors in multiple different markets (Baum & Korn, 1996; Bernheim & Whinston, 1990; Gimeno, 1999; Gimeno & Woo, 1994, 1996; Haveman & Nonnemaker, 2000; Jayachandran, Gimeno, & Varadarajan, 1999). In such situation, the chances of knowing, hurting or benefiting each other increase, allowing firms to recognize their interdependence, pressing them to be cautious when deciding which competitive actions to make because the outcome of a move depends heavily on how rivals respond to it (Baum & Korn, 1996; Bernheim & Whinston, 1990; Gimeno, 1999; Haveman & Nonnemaker, 2000; Jayachandran et al., 1999). This situation pushes firms to tacitly collude and mutually forbear (Bernheim & Whinston, 1990; Edwards, 1955; Feinberg, 1985), lowering the intensity of competition understood as the level of aggressiveness and speed of the actions and counteractions firms initiate to compete in the market (Chen, 1996). According to Smith, Ferrier and Ndofor (2001), most competitive actions can be classified as pricing actions, marketing actions, new product actions, capacity and scale-related actions, service and operations actions, and signaling actions. Each one describes a set of similar moves, that are assumed to have similar implications for the intensity of rivalry (Chen, 1996). However, in the field of marketing it is widely argued that many actions across categories are naturally interconnected (Borden, 1984; Constantinides, 2006; Magrath, 1986; McCarthy, 1978), and categorization used in competitive dynamics ignores that fact. Thus, in this dissertation, I propose to categorize all product, pricing, distribution, and promotional actions as marketing actions, and group them in the marketing mix (McCarthy, 1978), which presents marketing tactics as sets of actions that can be categorized as either product, price, promotion, or place. I emphasize in this dissertation that what is broadly accepted by competitive dynamics researchers as different competitive action categories should be considered all marketing actions, and equally important, these actions should be jointly analyzed as tactical competitive moves, rather than analyzed in isolation or as independent strategic action categories. Since tactical marketing actions, those of the marketing mix, are deployed on a day-to-day basis, even under multimarket contact conditions it may seem that competitive aggressiveness and intensity of competition increase, contrary to the tenets of the theory. In this line, I am proposing to analyze the consequences of multimarket contact from a tactical marketing perspective, mainly with the aim of understanding how firms under a multimarket contact setting deploy competitive movements at the marketing mix’s tactical level without disrupting mutual forbearance. For this, I will develop some hypotheses and test them using the Colombian car industry as empirical setting. / 1 / Juan Manuel González Sánchez
86

An exploratory study on information work activities of competitive intelligence professionals

Jin, Tao, 1971- January 2008 (has links)
No description available.
87

A Transgenic Mouse Model Approach to Investigate the Interactions Between T Cells during the Course of an Immune Response

Spencer, Alexandra Jane January 2006 (has links)
Doctor of Philosophy / The experiments described in this thesis document the development of two in vivo models, to investigate the effect of competition for peptide-MHC and factors independent of MHC on T cell proliferation, differentiation, generation of memory cells and affinity maturation. The first model made use of 3 strains of T cell receptor (TCR) transgenic (tg) mice of varying specificity for antigen-MHC class II. To determine the effect of antigen specific and non-specific competition on the early stages of the T cell response, the efficiency with which naïve antigen-specific CD4+ T cells were recruited into an ongoing immune response was investigated. Recruitment into cell division and cytokine production was shown to decrease with an increasing time delay between two cell cohorts of the same specificity, leading to a significant drop in recruitment with a delay of only 24 hours. Injection of additional antigen could partially compensate for this decrease, suggesting that lack of available antigen limited recruitment of specific cells trafficking to the node after the initiation of the response. A role for antigen non-specific factors such as access to APCs, costimulatory signals or cytokines was ruled out by showing that the response to a second, independent antigen was unaffected by an ongoing response, even when the same APCs were presenting both antigens. The second system modelled a situation in which a clone of uniformly high affinity T cells competed against a polyclonal population containing mixture of affinities. This situation would arise during a normal response to a single epitope, and would mimic the process of competition that drives affinity maturation of the CD4+ T cell response. By substituting a high affinity response to a different antigen, a more complex reaction to multiple antigens, of different affinities was modelled. To avoid any possible effect of the two antigens competing for access to processing machinery, or binding to the same MHC class II allele, the two antigens were provided as synthetic peptides that bind to different MHC molecules. The data indicated that CD4+ T cell competition for peptide-MHC is far more potent than competition between CD4+ T cell responses of different specificity. Antigen-specific competition reduced the level of T cell stimulation detected as early as day 3 of the response. In the face of high affinity antigen-specific competition, the representation of mixed affinity T cells within the effector and effector memory cells (TEM) population declined progressively throughout the primary and secondary responses, suggesting that continued access to peptide-MHC is required to maintain maximum numbers of effector and TEM cells. In contrast, the contribution of central memory (TCM) was stable from day 7 onwards. Competition by CD4+ cells of an unrelated antigenic specificity led to a minor reduction in peak cell number and cytokine production in the primary response, without altering the number or potency of memory cells. Together these two models demonstrated a mechanism whereby the immune system exerts tight control over the size and kinetics of each individual antigen specific response without affecting the ability to respond to secondary infections or late-phase lytic antigens. Overall the results demonstrate a continued requirement for TCR stimulation for the generation of effector cells and the maintenance of a population of cytokine producing memory cells. However the generation of a stable population of central memory cells was unaffected by conditions of reduced T cell stimulation, ensuring that long-term memory can be maintained in the absence of antigen.
88

Dynamic Pricing in a Competitive Environment

Perakis, Georgia, Sood, Anshul 01 1900 (has links)
We present a dynamic optimization approach for perishable products in a competitive and dynamically changing market. We build a general optimization framework that ties together the competetive and the dynamic nature of pricing. This approach also allows differential pricing for large customers as well as demand learning for the seller. We analyze special cases of the model and illustrate the policies numerically. / Singapore-MIT Alliance (SMA)
89

Variation of carbon allocation and competitive ability of different tree species as related to successional position and habitat /

Malavasi, Ubirajara Contro. January 1983 (has links)
Thesis (Ph. D.)--Oregon State University, 1984. / Typescript (photocopy). Includes bibliographical references (leaves 117-125). Also available on the World Wide Web.
90

Import and it's impact on domestic industries /

Kang, Hojin, January 1983 (has links)
Thesis (Ph. D.)--Ohio State University, 1983. / Includes bibliographical references (leaves 60-65). Available online via OhioLINK's ETD Center.

Page generated in 0.0876 seconds