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Resource allocation and <i>Hukou</i> status conversion : inequality under China's <i>Hukou</i> systemJin, Di 03 November 2009
The <i>Hukou</i> system has been a basic institution in Chinese society for several decades. My thesis explores whether, after nearly 30 years of reform and opening up in China, this system still plays a role in individuals lives and if so, what is this role? This study uses qualitative data from policy documents and quantitative data from the China General Social Survey 2003 to examine differences in income and access to welfare services among rural and urban <i>Hukou</i> holders and in <i>Hukou</i> status conversion both before and since the reform era and point out that the <i>Hukou</i> system contributes to inequality in individuals life chances in two dimensions: resource allocation and <i>Hukou</i> status conversion. The findings show that urban residents are advantaged in resource allocation before and in the reform era; the control mechanism of quota and policy for <i>Hukou</i> status conversion from rural to urban in the pre-reform era was replaced by the locally defined but nationally enforced entry conditions or requirements in reform era. The talented people, the CCP members, the people who have permanent jobs in urban areas, and the people whose family members hold urban Hukou are more likely now to overcome the <i>Hukou</i>-based control. The <i>Hukou</i>-based migration control continues on a localized basis and excludes the majority of rural residents from access to the rights enjoyed by urban residents. The findings of this thesis indicate that the consequences of the Hukou system continue today and additional reform still needs to be introduced.
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Host Plant Influences on Performance and Haplotype Diversity of Dalbulus maidis, a Specialist Herbivore of ZeaDavila-Flores, Amanda 14 March 2013 (has links)
In one study, a suite of plants from the maize genus Zea L. (Poaceae) and the specialist herbivore Dalbulus maidis (DeLong and Wolcott, 1923) (Hemiptera: Cicadellidae) were used to test the hypotheses that anti-herbivore defenses are affected by plant life-history evolution and human intervention through domestication and breeding for high yield. The suite of Zea host plants included one Mexican commercial hybrid maize Zea mays ssp. mays L., a landrace variety of maize, two populations of Balsas teosinte (Zea mays ssp. parviglumis Iltis & Doebley), and perennial teosinte (Z. diploperennis Iltis, Doebley & Guzman). This suite of host plants includes three Transitions evident within the genus Zea: life history form perennial to annual life cycle evident between perennial teosinte and Balsas teosinte, domestication transition from wild annual to domesticated annual evident between Balsas teosinte and landrace maize, and; breeding transition from landrace cultivar to a hybrid cultivar. The transitions were correlated with differences in plant defenses, as indicated by corn leafhopper performance. Results showed a performance gradient, suggesting a pattern in which plant defense is stronger in perennial than annual plants, Balsas teosinte than landrace maize, and in landraces than in hybrid maize. Furthermore, results suggested that domesticated maize would be the least defended, most suitable host for corn leafhopper.
In a second study, haplotype diversity was assessed to address structuring and interconnectedness among samples of corn leafhopper collected in the southwestern region of Mexico to address microevolution. The geographic focus of the study was maintained within an area encompassing the presumed centers of radiation of Dalbulus and its host genus Zea, and of maize domestication. Samples were complemented with samples of corn leafhopper sequences available at GenBank. Results revealed seven haplotypes from three host plants within Zea: perennial teosinte, Balsas teosinte, and maize. Furthermore, genetic differentiation was present and haplotype diversity appears to correlate with differences in genetic structure between perennial teosinte and maize. One haplotype was found to be present throughout all sites, which appears to parallel the spread of maize cultivation. As maize cultivation spread beyond its area of domestication, corn leafhoppers colonized perennial teosinte, further suggesting that subsequent decreases in maize cultivation in perennial teosinte habitat created a refuge where perennial teosinte- adapted haplotypes could persist. Altogether, my research suggests that the combination of historical expansion of maize cultivation expansion and the weaker anti-herbivore defenses associated within maize domestication appears to have favored genotypes particularly adapted for exploiting maize.
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Cooperative Relaying in Cellular NetworksKadloor, Sachin 12 February 2010 (has links)
We consider a system with a single base station communicating with multiple users over orthogonal channels while being assisted by multiple relays. Several recent works have
suggested that, in such a scenario, selection, i.e., a single relay helping the source, is the best relaying option in terms of the resulting complexity and overhead. However, in a multiuser setting, optimal relay assignment is a combinatorial problem. We formulate a related convex optimization problem that provides an extremely tight upper bound on performance and show that selection is, almost always, inherent in the solution. We also provide a heuristic to find a close-to-optimal relay assignment and power allocation across users supported by a single relay. Simulation results using realistic channel models demonstrate the efficacy of the proposed schemes, but also raise the question as to whether the gains from relaying are worth the additional costs.
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Signal Processing Methodologies for Resource-efficient and Secure Communications in Wireless NetworksBui, Francis Minhthang 15 July 2009 (has links)
Future-generation wireless and mobile networks are expected to
support a panoply of multimedia services, ranging from voice to
video data. There is also a de facto "anytime anywhere"
mentality that reliable communications should be ubiquitously
guaranteed, irrespective of temporal or geographical
constraints. However, the implicit catch is that these
specifications should be achieved with only minimal
infrastructure expansion or cost increases. In this thesis,
various signal processing methodologies conducive to attaining
these goals are presented.
First, a system model that takes into account the time-varying
nature of the mobile environment is developed. To this end, a
mathematically tractable basis-expansion model (BEM) of the
communication channel, augmented with multiple-state
characterization, is proposed. In the context of the developed
system model, strategies for enhancing the quality of service
(QoS), while maintaining resource efficiency, are then studied.
Specifically, dynamic channel tracking, adaptive modulation and
coding, interpolation and random sampling, and spatiotemporal
processing are examined as enabling solutions. Next, the
question of how to appropriately aggregate these disparate
methods is recast as a nonlinear constrained optimization
problem. This enables the construction of a flexible framework
that can accommodate a wide range of applications, to deliver
practical network designs. In particular, the developed methods
are well-suited for multi-user communication systems,
implemented using spread-spectrum and multi-carrier solutions,
such as code division multiple access (CDMA) and orthogonal
frequency division multiplexing (OFDM).
Moreover, privacy and security requirements are increasingly
becoming essential aspects of the QoS paradigm in
communications. Combined with the advent of novel security
technologies, such as biometrics, the conventional
communication infrastructure is expected to undergo fundamental
modifications to support these new system components and
modalities. Therefore, within the same framework for maximizing
resource efficiency, several unique signal processing
applications in network security using biometrics are also
investigated in this thesis. It is shown that a resource
allocation approach is equally appropriate, and productive, in
delivering efficient and practical key distribution and
biometric encryption solutions for secure communications.
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Node Selection in Cooperative Wireless NetworksBeres, Elzbieta 23 September 2009 (has links)
In this thesis, we argue for node selection in cooperative decode-and-forward networks. In a single-hop network with multiple relays, we show that selecting a single node to aid in the transmission between a source and a destination outperforms both
traditional orthogonal transmissions and distributed space-time codes. In networks where sources transmit information over
multiple hops and relays can communicate with each other, we study the relationship between cooperation and channel-adaptive routing.
We show that cooperation is only beneficial if designed jointly with a routing scheme. This motivates a search for optimal algorithms in generalized relay networks.
In networks without restrictions on the relays in terms of whom they can communicate with, we study the problem of optimal
resource allocation in terms of transmission time. The resource allocation selects the relays to participate in the transmission
and optimally allocates time resource between the selected relays.
To implement this resource allocation algorithm, we propose a recursive solution which reduces the computational complexity of
the algorithm.
For large networks, the resulting computational complexity of implementing the algorithm is exponential in the size of the
network and is likely to preclude its implementation. We thus propose that the resource allocation be implemented sub-optimally through node selection: a subset of the nodes in the network should be selected and used as input to the optimal resource allocation algorithm. We provide guidelines for selecting the nodes and propose four heuristics which offer various
complexity-performance trade-offs. Compared to the optimal resource algorithm, all four heuristics significantly decrease the
required computation complexity of the optimal algorithm.
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Cross layer scheduling and resource allocation algorithms for cellular wireless networksAli, Syed Hussain 11 1900 (has links)
This thesis considers the problem of cross layer scheduling and radio resource allocation of multiple users in the downlink of time-slotted and frequency-slotted cellular data networks. For these networks, opportunistic scheduling algorithms improve system performance by exploiting time variations of the radio channel. Within the broader framework of opportunistic scheduling, this thesis solves three distinct problems and proposes efficient and scalable solutions for them. First, we present novel optimal and approximate opportunistic scheduling algorithms that combine channel fluctuation and user mobility information in their decision rules. The algorithms propose the use of dynamic fairness constraints. These fairness constraints adapt according to the user mobility. The optimal algorithm is an off-line algorithm that precomputes constraint values according to a known mobility model. The approximate algorithm is an on-line algorithm that relies on the future prediction of the user mobility locations in time. We show that the use of mobility information increases channel capacity. We also provide analytical bounds on the performance of the approximate algorithm. Second, this thesis presents a new opportunistic scheduling solution that maximizes the aggregate user performance subject to certain minimum and maximum performance constraints. By constraining the performance experienced by individual users, who share a common radio downlink, to some upper bounds, it is possible to provide the system operator with a better control of radio resource allocations and service differentiation among different classes of users. The proposed solution offers better performance than existing solution under practical channel conditions. Finally, we present a dynamic subcarrier allocation solution for fractional frequency reuse in multicell orthogonal frequency division multiple access systems. We formulate the subcarrier allocation as an equivalent set partitioning problem and then propose an efficient hierarchical solution which first partitions subcarriers into groups and next schedules subcarriers opportunistically to users. Simulation results for three solutions illustrate the usefulness of the proposed schemes.
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Optimal Routing and Power Allocation for Wireless Networks with Imperfect Full-Duplex NodesRamirez Dominguez, David 24 July 2013 (has links)
We study a wireless full-duplex network with imperfect interference cancellation and solve the routing and power allocation problem in this network. We use a model that focuses on the effects of full-duplex by including residual self-interference and one hop interference while other interfering signals are considered negligible in comparison. We first solve the optimal power allocation for a fixed route. We then propose a priority-first search algorithm to find the joint route and power allocation to maximize throughput. The algorithm proposed has a non decomposable priority metric, but is efficiently evaluated by our solution for a fixed route. We analyze the performance of our solution in a more realistic model by deriving bounds between optimal solutions in both models. Through simulations we show that, even with imperfect interference cancellation, full-duplex achieves a higher throughput than half-duplex or direct transmission for moderate transmission power.
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Resource Allocation Decisions for the Internationalization of Small and Medium-Sized Manufacturing FirmsAdegorite, Adeoye Inaolaji 14 August 2013 (has links)
Abstract
This research explores the problems of resource allocation during the process of
internationalization by small and medium-sized manufacturing firms. The literature
largely portrays a positive view of internationalization with respect to increased firm performance or growth. However, particularly for Small and Medium-Sized Enterprises(SMEs), growth through internationalization increases uncertainty and may jeopardize firm performance and even threaten survival of the firm. The literature indicates that some SMEs fail during the process of expanding to foreign markets (Brewer 1981;Ramaswamy 1992; Mudambi and Zahra 2007). Many of these failures are due, in part,to the challenges of allocating limited resources during and after internationalization(Chen and Hsu 2009).
Given the challenge of internationalizing, this research examines the influence
of resource allocation on firm performance with the aim of providing recommendations
on how entrepreneurs can make better resource allocation decisions that in turn may
lead to improved performance. To address the problem of allocation of limited
resources during and after internationalization, theoretical propositions are developed
based on modern portfolio-theory (Markowitz 1952; 1959; 1991) that explains the risk-return tradeoffs with regards to resource allocation to domestic, U.S., and foreign
markets and possible effects on firm performance.
This research applies a multiple case-study approach based on critical realism, a
qualitative philosophical research paradigm. Data collection is through in-depth
interviews with executives of twenty-two small- and medium-sized manufacturing
firms located in Canada. Within-case and cross-case analyses findings are used to
confirm or modify the propositions, resulting in a descriptive model that best explains
resource allocation decisions and the effects on performance.
The findings indicate that resource allocations to domestic, U.S., and foreign
markets have different contributions to overall firm performance. However, the way in
which resource allocation trade-offs are decided between these markets is largely
dependent on the firms or owners/manager’s disposition to risks and returns. Findings
from this research also show that decisions by firm managers to allocate resources to a
particular market depend on their assessment or anticipation of risks and the potential
mitigation strategies that are required in order to maximize returns. This, consequently,
determines the firm’s performance during the process of internationalization.
This research contributes to the literature in international entrepreneurship,
management of technology, and decision analysis. While there is an extensive body of
literature that focuses on the output of internationalization (i.e., where, when, and how
firms export their products), few studies have specifically examined the inputs that
make this happen (one of these being the allocation of resources). Rugman et al. (2008)
examines the resource allocation decision between domestic and foreign markets for
Multinational Enterprises (MNEs) and the impact on firm performance. No known
study has specifically explored resource allocation decisions between domestic, U.S.,
and foreign markets for SMEs and the influence on firm performance. This research
fills the identified gap by making a significant theoretical contribution to this field by adopting portfolio theory to the challenge of allocating resources between domestic and foreign markets.
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Resource allocation and <i>Hukou</i> status conversion : inequality under China's <i>Hukou</i> systemJin, Di 03 November 2009 (has links)
The <i>Hukou</i> system has been a basic institution in Chinese society for several decades. My thesis explores whether, after nearly 30 years of reform and opening up in China, this system still plays a role in individuals lives and if so, what is this role? This study uses qualitative data from policy documents and quantitative data from the China General Social Survey 2003 to examine differences in income and access to welfare services among rural and urban <i>Hukou</i> holders and in <i>Hukou</i> status conversion both before and since the reform era and point out that the <i>Hukou</i> system contributes to inequality in individuals life chances in two dimensions: resource allocation and <i>Hukou</i> status conversion. The findings show that urban residents are advantaged in resource allocation before and in the reform era; the control mechanism of quota and policy for <i>Hukou</i> status conversion from rural to urban in the pre-reform era was replaced by the locally defined but nationally enforced entry conditions or requirements in reform era. The talented people, the CCP members, the people who have permanent jobs in urban areas, and the people whose family members hold urban Hukou are more likely now to overcome the <i>Hukou</i>-based control. The <i>Hukou</i>-based migration control continues on a localized basis and excludes the majority of rural residents from access to the rights enjoyed by urban residents. The findings of this thesis indicate that the consequences of the Hukou system continue today and additional reform still needs to be introduced.
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Which is the costlier sex? : Sexual dimorphism and resource allocation in a dioecious herb, Silene dioicaÅkerlund, Elisabet January 2011 (has links)
Life-history theory proposes that different activities, such as growth, maintenance and reproduction compete for limited resources and therefore, life-history traits are bound together by physiological trade-offs. In dioecious species, females are assumed to invest a higher amount of resources in reproduction in comparison with males and this higher investment in reproduction is then assumed to have numerous consequences for the expression of other life-history traits. Some recent papers have, however, suggested that although common, this investment pattern may not be the case in all dioecious plant species. One notable exception is Silene latifolia. Therefore, I examined whether the male sex could be investing more in reproduction than females in a closely related Silene species, Silene dioica. This study was carried out on three islands in the Skeppsvik Archipelago, Umeå, where I examined possible differences between the sexes in different life history traits. On each island, 20 patches were laid out in two different successional zones. In each patch, flowering date was recorded and stem diameter, length and width of cauline leaves, flower diameter, and number of open flowers on male and female plants was measured. At the end of the study, flowering stems were collected and thereafter dried so they could be weighed to estimate biomass allocated to male and female vegetative and reproductive structures. The hypothesis that males of S. dioica should have a higher reproductive cost seemed to be confirmed since males started flowering earlier, produced more and larger flowers, produced smaller and fewer leaves and thinner stems. The males also allocated a greater proportion of their total biomass to reproductive parts and as a consequence, had a higher sink to source ratio. This study has shown that there are exceptions to the "rule" of females having a higher cost of reproduction and when doing research on dioecious species, it is important not to assume that only one and the same sex has the higher investment in reproduction in all species. This higher cost may have consequences for survival and reproductive fitness and can select for differences in other ecological traits, such as phenology, growth, chemical composition and morphology, which could in turn affect the competitive ability and the susceptibility to herbivores and pathogens.
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