Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 182-198).

This work is related to wireless communication. In this Thesis three main issues are addressed for future cellular networks: power consumption, interference and mobility. These issues continue to be a burden on the system’s performance as long as technology keeps evolving. In the presented chapters, the focus was to introduce greater intelligence to the LTE system algorithms and bring to them a dynamic and self-organizing approach. The first approach concerns power consumption in wireless terminals. The currently applied solution to save energy is the DRX mechanism. It organizes the time when the terminal wakes up and starts receiving data, and when it goes into sleep mode in order to save its battery power. The current DRX is described as static or fixed which makes its parameters unsuitable for the nature of the bursty traffic. In this work an adaptive DRX mechanism is proposed and evaluated as the wireless terminal battery saving algorithm. The second approach is co-channel interference mitigation. To increase the system’s capacity and avoid spectrum scarcity, small cells such as Femtocells are deployed and operate on the same frequency bands as the Macrocell. Although these small nodes increase the system capacity, however, the challenges will be in the femtocells planning and management in addition to the interference issues. Here a dynamic interference cancellation approach is presented to enable the Femtocell to track the allocated resources to the Macro-users, and to avoid using them. The third approach concerns mobility management in heterogeneous networks. The wireless terminal may have different mobility levels during handover which increases the handover failures due to failure in handover commands and aging of the reported parameters. This issue is presented in detail with the aim to avoid performance degradation and improve the reporting mechanisms during fast mobility levels. For this regard the presented method proposes more cooperation between the serving cell and the end-user so that the large amount of overhead and measurement are reduced. Simulations with different configurations are conducted to present the results of the proposed models. Results show that the proposed models bring improvements to the LTE system. The enhanced self-organized architecture in the three presented approaches performs well in terms of power saving, dynamic spectrum utilization by Femtocells, and mitigation of sudden throughput degradation due to the serving cell’s downlink signal outage during mobility.

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.Most countries in the SADC region experience low levels of domestic savings. This calls for the need to explore other sources of financial flows to bridge the gap between domestic capital demand and supply, and one such source is external financial flows. It is with this background that this study examined the relationship between the different forms of external financial flows, domestic savings and economic growth in the SADC region for the period from 1980 to 2013. Firstly the study examined the impact of the different forms of external financial flows on economic growth in the region. The empirical results revealed that FDI, CBF and remittances have a significant impact on economic growth in the SADC region. ODA was however found to be insignificant. When the different types of external financial flows were interacted with institutions they all became significant in explaining economic growth in the region. The second aspect was to examine the extent to which external financial flows complement or displace domestic saving. The empirical results revealed that external financial flows with the exception of ODA complement domestic savings in the region. In addition, there is evidence of investment generating additional savings in the region, which is likely to be through the economic growth channel. The last objective of the study was to examine the determinants of external financial flows to the SADC region. The empirical results revealed that both push and pull factors are important in determining external financial flows in the region. Of great importance was the observation that events in the source country determine financial flows to the region. Proxy for financial integration was found to be positive though insignificant, pointing out that the region may not be benefiting from cross-border bank flows due to the region being disintegrated. This suggests that the region may benefit from increased cross-border bank flows if the region is integrated. Overall, the results from the study suggest that external financial flows are important to the region in providing the much needed development finance. However this also suggests that the foreign capital channel is another source in which a crisis from a developed country can be transmitted to the SADC region.

Problem: Few studies regarding savings among students have been conducted, particularly studies looking at students in Sweden, as the general assumption is that students cannot save.   Purpose: Investigate what factors may affect students saving behavior   Method: The thesis will be done by a quantitative and deductive approach. To investigate what factors affect students saving we conducted several hypotheses tests through regression analysis.   Result and Conclusion: The investigation showed that through our estimates we were able to find three significant variables at a 5% level; Income, Worked Before and Saving Before and a general fit of the model of 16.36%. One possible explanation for the poor fit is the complexity of human behavior and thusly that it is hard to explain.   Keywords: Students, saving, consumption theory, statistics, age, behavioral, finance

This dissertation addresses three issues in international macroeconomics. The first chapter examines optimal portfolio decisions in a monetary open economy DSGE model. In a complete market environment, Engel and Matsumoto (2005) find that sticky price can generate equity home bias. However, their result is sensitive to the structure of the financial market. In an incomplete market environment, we find “super home bias” in the equilibrium equity portfolio, which casts doubt on the ability of sticky price in describing the observed equity portfolios. We further show that introducing sticky wages helps to match the data. The second chapter analyzes the welfare impact of financial integration in a standard monetary open-economy model. Financial integration may have negative effects on welfare if integration occurs in the presence of nominal price rigidities and constraints on the efficient use of monetary policy. The reason is that financial integration leads to excessive terms of trade volatilities. From a policy perspective, the model implies that developing economies that are experiencing financial integration may attempt to alleviate the welfare cost of integration by stabilizing the exchange rate. This prediction is consistent with the widespread reluctance to following freely floating exchange rates among these economies. On the other hand, for advanced economies that have the ability to operate efficient inflation targeting monetary policies, financial integration is always beneficial. Thus, the model accounts for the observed acceleration in cross-border asset trade among advanced economies in the early 1990s as it was mainly the industrial countries that switched to an inflation targeting regime at the time. The third chapter uses an open-economy neoclassical growth model to explain the saving and investment behavior of the U.S. and a group of other OECD countries. We find that while the model explains investment quite well, it tends to overpredict U.S saving and underpredict saving in the rest of the world. We show that the closed-economy version of the model also predicts saving accurately but that is only because it imposes equality between saving and investment. In effect, the model explains investment not saving behavior. / Arts, Faculty of / Vancouver School of Economics / Graduate

Master of Science / Department of Horticulture, Forestry, and Recreation Resources / Candice A. Shoemaker / Seed saving, whether performed by subsistence farmers, by breeders at land grant universities, or the seed industry, provide the world’s farmers with the needed supply of seeds to produce food crops annually. This thesis considers historical agricultural trends as they relate to the process of seed saving. It utilizes information gathered from primary source materials, historical monographs, and FAO and NGO publications. Chapter two discusses six universal agricultural dichotomies and how they relate to seed saving over time and globally. The dichotomies examined as they relate to seed saving include: subsistence and commercial, commons and commodity, public and private, basic and applied, global north and south, and urban and rural food production. Subsistence and commons oriented agricultural systems have historically traveled towards commercial and commodity forms in developed countries like the United States. As a result, seed saving moved from something farmers did to either public or private institutions that performed basic and applied research for genetic improvement of agricultural crops. As breeding programs looked outward for better breeding materials (germplasm) the importance of the Global North and South and Urban and Rural locales became important. Based on the results of this examination, it is clear that prioritizing subsistence practices and understanding seeds as a commonly held resource play important roles in maintaining agricultural diversity, particularly for more commercialized and commodity oriented agricultures. This shift from subsistence to commercial agriculture in the Global South jeopardizes subsistence agriculture’s ability to maintain agricultural diversity. Chapter three utilized a case study framework and focused on American seed saving within the Corn Belt from 1890 to 1950. The Corn Show, a common annual showcase of corn seed savers in the Midwest, supported both subsistence and commercial agricultural ideals. It also set the stage for the introduction of hybrid corn and suggested an alternative to the commodification of seeds by the industry. These results suggest that seed saving programs today could benefit from a culture that values subsistence practices while still utilizing the benefits of contemporary methods that are common to commodification. The added benefit of community and diversity that are realized by seed saving could develop a culture of seed production that is capable of contributing to rural development goals. This thesis concludes by tying together its discussion of dichotomies, reinforcing the connectedness between different agricultural production systems, and thus, the need for many different types of seed saving.

The volatility of stock markets has important implications for investment decision making, financial stability and overall macroeconomic stability. This study examines the risk-return relationship as well as the behaviour of volatility of the South African equity markets using both aggregate, industrial level and sector level data. The study is divided into three parts. The first part investigates the behaviour of volatility in each of the industries, sectors and the benchmark series focussing on whether volatility is symmetric or asymmetric. Subsequently we investigate which, among the GARCH family of models appropriately captured the riskreturn relationship under which distributional assumption. The second part examines the riskreturn relationship on the SA stock market. The third part examines the long term trend of volatility and whether volatility significantly increases during financial crises and during major global shocks. The GARCH-M, EGARCH-M and TARCH-M models under the Gaussian, Student –t and the GED are used. The findings this study makes are as follows: firstly, there is no clear relationship between risk and return. Secondly, volatility is asymmetrical, implying that bad news has a greater effect on volatility than good news in the South African equity market. Thirdly, the TARCH-M model under the GED was found to be the most appropriate model. Fourthly, volatility increases during financial crises and major global shocks. Overall, volatility is generally not priced on the South African equity markets. Thus, both local and international investors need to consider other factors that influence returns such as skewness. The general increase in volatility during financial crises and major global shocks poses a major concern for policy makers as this may cause financial instability. Thus policy makers need to be mindful of the behaviour of volatility in the South African equity market in response to external shocks.

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