Cooperative communication has been considered a promising technique used in wireless network to introduce diversity. Based on distributed architecture, cooperative network enables single-antenna users to share their information as a virtual multiple antenna array, which makes it possible to enhance the user data rates and obtain the diversity gain. Depending on the ways users share and process the information, practical user cooperation is mainly grouped in three modes: Amplify and Forward (AF), Decode and Forward (DF) and Compress and Forward (CF). Generally, DF outperforms AF in most practical implementation and is alternately the best by theoretical analysis. In particular, it is shown in theory that DF outperforms CF when the inter-user link is in good condition and vice versa. Considered as a capacity achieving approach, superposition encoding technique produces approximate Gaussian output signals. It is the power and spectral efficiency of the encoding scheme that make it useful for several wireless communication systems such as MIMO system, relay channels, and so on. The main goal of the thesis is to study how much superposition coding can help when applied to DF user cooperation. In particular, a new DF scheme with soft information relaying technique is proposed to overcome the performance degradation happening when the quality of the inter-user channel is bad. Based on the scheme, soft log-likelihood ratio (LLR) of the relay decoder is quantized, encoded, modulated by superimposition and then forwarded to the destination. The destination receiver employs an iterative superposition decoder and modified maximum a posteriori probability (MAP) decoder to recover the transmitted signal from the source. The performance of the scheme is evaluated by simulation. We show that the new scheme can significantly outperform the conventional DF scheme even in a poor inter-user channel. Furthermore, a new cooperative transmission strategy based on superposition and multiuser detection techniques is also investigated in the thesis. The new scheme is an improved DF scheme in which the two users take turns in being the relay for each other and the signal forwarded by each user is the superimposed data of both users. Here, interleavers are introduced in the superposition process as an efficient user separation tool, providing a large improvement in error performance and also facilitating the decoding process at the destination. Different types of iterative receivers are examined. The performance of the scheme is evaluated by simulation. It is shown that the new transmission scheme outperforms the conventional one in terms of both spectral and power efficiency.

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Taxonomic boundaries and systematic relationships in the grass subspecific complex Dichanthelium acuminatum were investigated with both morphological and molecular methods. Circumscription of subspecific taxa comprising the complex has been difficult due to a continuum of morphological character variation among taxa and possibly due to infraspecific and interspecific hybridization. Qualitative and quantitative morphological character data was collected from herbarium specimens and field-collected specimens and analyzed using multivariate statistical techniques. Representative specimens were selected for molecular phylogenetic analysis of DNA sequences from the GBSSI (waxy) nuclear gene. Subspecific boundaries as circumscribed in the most recent taxonomic treatment (10 subspecies) were tested from: 1) a morphological perspective with results of the multivariate statistical analysis to determine if the study specimens formed natural groupings that corresponded to the recent treatment; and, 2) with molecular phylogenetic analysis to estimate the evolutionarily significant lineages present and to determine if such lineages supported the natural groupings revealed from the multivariate morphological analysis. A separate investigation was conducted using a molecular technique to screen for putative hybrid specimens from DNA obtained from field-collected specimens. Multivariate statistical analysis of the morphological data provided support for four of the 10 taxa tested and additional support for two taxa considered as a single unit. Further research is needed to determine the appropriate status of the remaining six taxa of the ten taxa tested. Molecular phylogenetic analysis provided support for recognizing four evolutionarily significant units and provided parallel support for four of the five taxa recognized from the morphological analysis. The hybridization investigation identified two putative hybrid specimens, which were confirmed as hybrids with GBSSI sequence data and also with multivariate statistical analysis of morphological data to provide provisional evidence for the role of hybridization in producing specimens with intermediate morphological phenotypes. A taxonomic treatment and dichotomous key was produced for the 10 subspecific taxa of the Dichanthelium acuminatum complex.

It is shown that there is an unconditional requirement on rational beings to adopt “reflexive” beliefs, these being beliefs with a very particular sort of self-referential structure. It is shown that whoever adopts such beliefs will thereby adopt beliefs that imply that a certain proposition, ᴪ, is true. From the fact that there is this unconditional requirement on rational being to adopt beliefs that imply ᴪ, it is concluded that ᴪ is knowable a priori. ᴪ is a proposition that says, in effect, that one’s own point of view is a point in space and time that is the point of view of some being who has reflexive beliefs. It is argued that this information that is contained in ᴪ boils down to the information that one’s point of view is located at a point in the world at which there is something that is “conscious” in a certain natural and philosophically interesting sense of that word. In other words, a theory of consciousness is defended according to which an entity is conscious if and only if it has reflexive beliefs.

Environmental degradation is one of the most important problems facing by Chinese people. This unsatisfactory situation majorly lies in the weak implementation of environmental laws. The essential reason causing the ineffective enforcement of Chinese environmental law is people’s distorted cognition about the relation between human being and the environment. As an important principle of international environmental law, the sustainable development principle emphasizes intra-generational and intergenerational equality, aiming to realize a balance of environmental interest and socie-economic interest, which could become the guideline of the reformation of Chinese environmental law enforcement mechanism. At last, this paper analyzes the solutions to appeared problems, which are underpinned by the sustainable development principle. The ultimate purpose is to promote rational policies and responsible conducts of governments, to foster enterprises’ voluntary compliance with environmental law and to foster citizens’ environmental awareness.

Environmental degradation is one of the most important problems facing by Chinese people. This unsatisfactory situation majorly lies in the weak implementation of environmental laws. The essential reason causing the ineffective enforcement of Chinese environmental law is people’s distorted cognition about the relation between human being and the environment. As an important principle of international environmental law, the sustainable development principle emphasizes intra-generational and intergenerational equality, aiming to realize a balance of environmental interest and socie-economic interest, which could become the guideline of the reformation of Chinese environmental law enforcement mechanism. At last, this paper analyzes the solutions to appeared problems, which are underpinned by the sustainable development principle. The ultimate purpose is to promote rational policies and responsible conducts of governments, to foster enterprises’ voluntary compliance with environmental law and to foster citizens’ environmental awareness.

This thesis explores the relative strengths of particularism and generalism in the area of meta-ethics in philosophy, utilising justice as a case study. More specifically, this thesis examines the claims of Jonathan Dancy in his book on moral particularism, Ethics Without Principles (2004), that one can construct a moral philosophy without reference to any general principles, or invariant reasons. His book is primarily a study of reasons, and this thesis also presents a study of reasons through the eyes f both the particularists and the generalists. At its core, the particularism holds holism to be true in the theory of reasons, whereas generalism, at its core, holds atomism to be true in the theory of reasons. In my thesis I find that the strongest form of atomism and the strongest form of generalism is Rossean generalism. I conclude that these two pictures combined provide a superior account of what reasons are and how they work than Dancy's particularism. / Thesis (M.A.)-University of KwaZulu-Natal, Pietermaritzburg, 2005.

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Real space renormalisation group scaling techniques are used to investigate the static critical behaviour of the pure and dilute, classical, anisotropic Heisenberg model. Transfer matrix methods are employed to obtain asymptotically exact expressions for the correlation lengths and susceptibilities of the one-dimensional system. The resulting scaling relationships are combined with an approximate bond moving scheme to treat pure and dilute models in higher dimensionalities. Detailed discussions are given for the dependence of correlation lengths and susceptibilities on temperature, anisotropy and concentration, and fcr the critical temperature on anisotropy and concentration. Particular emphasis is given to the weakly anisotropic system near percolation threshold and comparisons are made between the results of the present analysis and those of neutron-scattering experiments on dilute quasi-two- and three-dimensional systems.

Empirical studies have shown that white racial attitudes tend to predict racial policy support. It has also been established that the relationship between whites' espoused racial tolerance and their support for ameliorative racial policies is imperfect, due to the principal-policy gap which characterized misalignment between individuals' espoused values for racial equity and their limited support for policies aimed at achieving those ends. Less consideration however, has been given to how the principal-policy gap changes over time. Using data from over 14,000 respondents who participated in the General Social Survey from 1994 through 2018, I show that the principal-policy gap is persistent, and that distances between principal and policy decline and expand over time. Using OLS regression models to analyze a sample of white adults, I find that the link between individuals' expressed liberal racial attitudes and their support for racial policies changed over the 24-year span. A noticeable narrowing of the principal-policy gap is also evident in the latter years of the sample. The reduction in the gap from 2014 through 2018 suggests that the influence of social movements like BLM may have been driving this trend.