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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.
221

Evolution of the rare earth trade network: from the perspective of dependency and competition

Xu, J., Li, J., Vincent, Charles, Zhao, X. 22 June 2023 (has links)
Yes / As a global strategic reserve resource, rare earth has been widely used in important industries, such as military equipment and biomedicine. However, through existing analyses based on the total volume of rare earth trade, the competition and dependency behind the trade cannot be revealed. In this paper, based on the principle of trade preference and import similarity, we construct dependency and competition networks and use complex network analysis to study the evolution of the global rare earth trade network from 2002 to 2018. The main conclusions are as follows: the global rare earth trade follows the Pareto principle, and the trade network shows a scale-free distribution. China has become the largest country in both import and export of rare earth trade in the world since 2017. In the dependency network, China has become the most dependent country since 2006. The result of community division shows that China has separated from the American community and formed new communities with the Association of Southeast Asian Nations (ASEAN) countries. The United States of America has formed a super-strong community with European and Asian countries. In the competition network, the distribution of competition intensity follows a scale-free distribution. Most countries are faced with low-intensity competition, but competing countries are relatively numerous. The competition related to China has increased significantly. The competition source of the United States of America has shifted from Mexico to China. China, the USA, and Japan have been the cores of the competition network. / This work was supported by the Ministry of Education of the People’s Republic of China Humanities and Social Sciences Youth Foundation (Grant No. 22YJC910014), the Social Sciences Planning Youth Project of Anhui Province (Grant No. AHSKQ2022D138), and the Innovation Development Research Project of Anhui Province (Grant No. 2021CX053).
222

Zambias Lån och SEZs från Kina : Ett verktyg för utveckling genom interdependens eller neocolonialism? / Zambia's loans and SEZs from China : A Tool for Interdependence or Neocolonialism?

Petré, Erik January 2024 (has links)
This thesis examines the relationship between China and Zambia through an in-depth study of Chinese investments and loans, focusing specifically on Special Economic Zones (SEZs). The central research question investigates whether China’s economic involvement in Zambia fosters mutual development through interdependence or contributes to neocolonialism. Chinese loans to Zambia have been substantial, enabling significant infrastructure projects. However, these loans have also led to increased debt dependency, limiting Zambia's economic sovereignty. The frequent need for loan forgiveness highlights the sustainability issues of this financial model. Chinese investments in Zambia, particularly in SEZs, aim to stimulate economic growth. While these investments have led to job creation and infrastructure development, there is criticism that they primarily benefit Chinese interests and perpetuate an extractive economic model. China's involvement in Zambia raises concerns about political influence. The dependence on Chinese loans and investments can potentially undermine Zambia's political sovereignty, as seen in instances where Chinese financial support has continued despite Zambia’s debt crisis. The influx of Chinese companies and workers has had mixed social effects. While creating employment, it has also sparked debates about labor conditions and environmental practices. The balance between economic benefits and social costs remains a contentious issue. This thesis employs both neocolonialism and interdependence as theoretical frameworks to analyze these dynamics. Neocolonialism helps in understanding the power imbalances and economic dependency that may arise from China's strategic investments. In contrast, the interdependence perspective highlights the potential for mutual benefits and collaborative economic growth. Overall, the relationship between China and Zambia is complex, characterized by both opportunities for development and risks of dependency. The results show that China shows slightly more neocolonialistic tendencies, rather than working towards interdependence.
223

Diameter Distributions of Juvenile Stands of Loblolly Pine (Pinus taeda L.) with Different Planting Densities

Bullock, Bronson P. 13 March 2002 (has links)
Diameter distributions of juvenile loblolly pine (Pinus taeda L.) with different planting densities were characterized utilizing a two-parameter Weibull distribution. Trend analysis was employed to describe the effects of planting density, age, relative spacing, and rectangularity on the estimated diameter distributions for juvenile loblolly pine. A reparameterization of the two-parameter Weibull distribution was sought to reduce the dispersion of the estimated shape parameter. Methods that quantify the amount of inter-tree spatial dependency in a particular stand were applied. Empirical semivariograms were derived for each plot over all ages to enable spatial trend recognition. Moran's I and Geary's C coefficients were estimated for ground-line diameters from ages 2 to 5, and for breast height diameters from ages 5 to 11. Though there was no discernable trend in the presence of significant spatial autocorrelation with planting density, an initial negative trend with age was present, but leveled off by age 5. A conditional autoregressive model was utilized to evaluate the amount of spatial influence stems in a stand have on one another. The occurrence of significant spatial influences was positively associated with age through age 8, the trend then leveled off; no recognizable trend was detected with planting density. These indices help to describe stand dynamics that are influenced by the spatial distribution of stems. Models to predict the parameters of the two-parameter Weibull distribution were developed to aid in forecasting and simulation of juvenile loblolly pine. Simulations were conducted where a spatial dependency was imposed on the diameters within a stand. The spatial structure simulation enables accurate representations of stem characteristics when simulating forest stands that include spatially-explicit information. / Ph. D.
224

The Effects of Context-Dependency of Seductive Details on Recall and Transfer in a Multimedia Learning Environment

Ozdemir, Devrim 25 June 2009 (has links)
The purpose of this study was to investigate the effects of context-dependency of seductive details on recall and transfer in multimedia learning environments. Two experiments were conducted. In Experiment 1, the purpose was to identify context-dependent vs. context-independent seductive details in a lightning animation. Seductive details were considered as interesting yet irrelevant sentences in the narration of lightning animation. Sixty-seven undergraduate students participated in Experiment 1 and assigned interestingness scores to the 28 content irrelevant sentences. Participants were assigned to two different groups, context-dependent seductive details group (CDSD) and context-independent seductive details group (CISD). Participants in the CDSD group assigned interestingness scores after watching a lightning animation to be familiarized with the context of lightning formation. Participants in the CISD group watched a historical inquiry animation as a distraction task before assigning interestingness scores. The results of Experiment 1 revealed that 13 of 28 sentences in the lightning formation text were seductive details according to participants of the study. Ultimately, 6 of the 13 seductive details were determined to be context-dependent and 7 were determined to be seductive details were context-independent. The purpose of Experiment 2 was to investigate the effects of context-dependency of seductive details on recall and transfer in multimedia learning environments. Undergraduate students (n = 184) were randomly assigned into four groups. Participants in all groups watched a lightning animation, and performed a recall and a transfer task. The first group watched an animation that did not include any seductive details. The second group watched the animation with context-dependent seductive details only. The third group watched the animation with context-independent seductive details only. The last group watched the animation with both types of seductive details. A 2x2 ANOVA for both recall and transfer, and contrast analyses were conducted to determine the effects of context-dependency of seductive details on recall and transfer. The results indicated that there was no significant effect of context-dependency of seductive details on recall or transfer. The findings are discussed in the context of the related literature and directions for future research are suggested. / Ph. D.
225

Effects of Field Dependent-Independent Cognitive Styles and Cueing Strategies on Students' Recall and Comprehension

Cao, Yu 29 September 2006 (has links)
The purpose of this study was to examine whether cueing strategies embedded in computer delivered text messages affected the recall and comprehension of students who differed in their field dependent-independent cognitive style orientations. Two hundred thirty-eight undergraduate students of Virginia Tech participated the study, and 219 sets of valid data were used for the statistical analyses. All participants were given the Group Embedded Figures Test to determine their level of field dependence-independence. They were then randomly assigned to one of three treatment groups that varied in their use of cueing strategy. The first treatment group featured computer delivered text messages with color-highlighted-keywords, the second group featured the same textual content with color-highlighted-key-phrases, and the third group was a control group that featured the same content and employed no cueing strategy. Participants were administered two tests following the treatments, one that assessed knowledge of terminology and another that assessed comprehension. A 3 x 3 Analysis of Variance was conducted to explore the main effects for field dependency and cueing strategy and any interaction effect between the two factors. The results showed that field independents outperformed field dependents in all tests. There were no significant differences for the three treatments; the cueing strategies employed in this study had no effect on participants' learning. A significant interaction was seen between field dependency and cueing strategy. However, the results of a one-way ANOVA are unexpected: the cueing strategies employed did not improve field dependents' performance on the assessments and actually hindered the performance of field independents. / Ph. D.
226

Localized Muscle Fatigue: Theoretical and Practical Aspects in Occupational Environments

Rashedi, Ehsan 15 January 2016 (has links)
Localized muscle fatigue (LMF) is a complex, multifactorial phenomenon that involves exercise-induced decrements in the ability to generate force or power. LMF can adversely affect performance and may increase the risk of work-related musculoskeletal disorders (WMSDs), and is thus of contemporary occupational relevance. Despite considerable progress in understanding and predicting muscle fatigue, there are many uncertainties and unresolved issues that are principally associated with the physiological complexity of LMF and the diverse mechanisms that underlie LMF development. This research thus aimed to address some of the theoretical and practical issues related to muscle fatigue and recovery. Regarding the theoretical aspects, two specific muscle fatigue models (MFMs) were directly compared and some important differences in their predictions were identified. These differences were used, in part, as a basis for developing testable hypotheses and designing associated experiments. Further theoretical evaluations were conducted to explore the sensitivity of these models to the model parameters and their ability to predict endurance time in both prolonged and intermittent exertions. Sensitivity to inherent model parameters was quantified, which was relatively high in conditions involving lower to moderate levels of effort. Further assessments indicated substantial variability related to model recovery parameters, which might be related to the inability of these MFMs in simulating the recovery process. From a practical viewpoint, the effect of cycle time on the development and consequences of LMF was determined during intermittent isometric exertions. A shorter cycle time led to less fatigue development as reflected by rates of change in perceived discomfort, performance, and muscle capacity. Lastly, the dependency of muscle recovery on these different histories of fatiguing muscle contractions was explored. How a muscle recovers appeared to depend only on the state from which it starts to recover, though not the exertion history that led to that state. In summary, results of these studies may help in enhancing our understanding of fatigue and recovery processes, and in improving existing models of muscle fatigue and recovery. More accurate predictions of LMF development may help in enhancing muscle performance and in reducing the risk of musculoskeletal injuries and their associated healthcare costs. / Ph. D.
227

Encouraging the Arts through Higher Education Institutions: Arts Policy Implementation in Virginia

Keeney, Katherine Preston 27 May 2014 (has links)
This dissertation investigates the role of public higher education institutions in state-level arts policy in the state of Virginia. The strength of public support for the arts historically has been measured by per capita arts spending, as determined by appropriations to state arts agencies. However, this is a very thin measure that misses an increasingly important contributor to the arts policy landscape - higher education institutions. As direct sources of funding for the arts decline, universities increasingly are contributing to the state arts landscape with the construction and operation of performing arts centers. Framed by resource dependency theory and rational choice institutionalism, this research sheds light on the motivations of actors contributing to the arts policy field in a resource-scarce environment. Evidence suggests that public higher education institutions invest in the co-curricular arts to capitalize on and acquire resources, including image and prestige, and to fulfill their public service missions. Although higher education institution performing arts centers are contributing to the state's arts landscape, they are only informally participating in arts policy formulation and implementation. These findings have financial and decision-making implications for arts policymakers, university administrators, and arts agencies as the inclusion of public higher education institutions in the arts policy field affords new opportunities and challenges for the state encouragement of the arts. / Ph. D.
228

The Multidimensional Interpersonal Dependency Inventory: Scale Development

Shlien, Rania K. 22 January 2001 (has links)
Current inventories of interpersonal trait dependency are problematic because they are based on theories that fail to recognize the positive aspects of dependency. The main goal of this thesis was to develop a new inventory that takes into account theoretical advances using Robert Bornstein's definitions and identified components of interpersonal dependency. The study was broken into the following three stages: 1. Item and inventory creation, 2. Expert feedback and interrater reliability and 3. Data collection and analysis. Three-hundred fifteen undergraduates completed a questionnaire packet, consisting of a demographics section, a copy of the new inventory, and seven other inventories that measure dysfunction and well-being. Although the original hypotheses in this work were not supported, exploratory factor analysis yielded four factors. These four factors and their relevance to the measurement of interpersonal dependency are discussed and suggestions are made for future studies. / Master of Science
229

The Effects of Open Source License Choice on Software Reuse

Brewer, John VIII 08 June 2012 (has links)
Previous research shows that software reuse can have a positive impact on software development economics, and that the adoption of a specific open source license can influence how a software product is received by users and programmers. This study attempts to bridge these two research areas by examining how the adoption of an open source license affects software reuse. Two reuse metrics were applied to 9,570 software packages contained in the Fedora Linux software repository. Each package was evaluated to determine how many external components it reuses, as well as how many times it is reused by other software packages. This data was divided into subsets according to license type and software category. The study found that, in general, (1) software released under a restrictive license reuse more external components than software released under a permissive license, and (2) that software released under a permissive license is more likely to be reused than software released under a restrictive license. However, there are exceptions to these conclusions, as the effect of license choice on reuse varies by software category. / Master of Science
230

Modeling C2 Networks as Dependencies: Understanding What the Real Issues Are

Drabble, Brian January 2014 (has links)
No / This chapter describes an approach to modeling C2 and other types of networks as a series of nodes (people, groups, resources, locations, concepts, etc.). The nodes are linked by one or more weighted arcs describing the type and the strength of the dependency that one node has on another node. This model allows analysts to identify the most important nodes in a network in terms of their direct and indirect dependencies and to rank them accordingly. The same model also supports consequence analysis in which the direct, indirect, cascading, and cumulative effects of changes to node capabilities can be propagated across the networks. The chapter describes the basic modeling technique and two types of dependency propagation that it supports. These are illustrated with two examples involving the modeling and reasoning across insurgent networks and an Integrated Air Defense System. These show how aspects of the networks can be analyzed and targeted. Details are also provided on the mechanisms to link the analysis to a planning system through which plans can be developed to bring about desired effect(s) in the networks.

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