The cultural and historical construction of African American identity in the United States has been closely tied to the dialectical relationship formed between sound and silence. This thesis examines the modernist and postmodernist representation of sound and silence in the African American novels Passing (1929), by Nella Larsen, and Jazz (1992), by Toni Morrison, as indicators of African American identity and racial oppression during the Harlem Renaissance. I analyze the soundscapes of both texts to expose the mobility of language, power, and space, especially as these soundscapes relate to the production of sound (both musical and non-musical) by African Americans, and the surveillance of these sounds by white audiences. Through my analysis of repetitive sound-images and embodied silence in Passing and Jazz, as well as textual representations of oral performance, I argue that there is harm in restricting African American voices to approved modes of audibility and/or limiting African American voices to one a singular narrative. This thesis introduces critics and theories from the disciplines of sound studies and African American studies, and applies the widely known theory of double consciousness, established by critic and author W.E.B. Du Bois, as the foundation for my literary and cultural analysis of sound in print. / Graduation date: 2013

Large-eddy simulation (LES) and unsteady Reynolds-averaged Navier-Stokes (URANS) calculations have been performed to investigate the effects of different mathematical models for scalar variance and its dissipation rate as applied to both a non-reacting bluff-body turbulent flow and an extension to a reacting case. In the conserved scalar formalism, the mean value of a thermo-chemical variable is obtained through the PDF-weighted integration of the local description over the conserved scalar, the mixture fraction. The scalar variance, one of the key parameters for the determination of a presumed β-function PDF, is obtained by solving its own transport equation with the unclosed scalar dissipation rate modelled using either an algebraic expression or a transport equation. The proposed approach is first applied to URANS and then extended to LES. Velocity, length and time scales associated with the URANS modelling are determined using the standard two-equation k-ε transport model. In contrast, all three scales required by the LES modelling are based on the Smagorinsky subgrid scale (SGS) algebraic model. The present study proposes a new algebraic and a new transport LES model for the scalar dissipation rate required by the transport equation for scalar variance, with a time scale consistent with the Smagorinsky SGS model.

The objective of this thesis is to automate the design of round-robin arbiter logic. The resulting arbitration logic is more than 1.8X times faster than the fastest prior state-of-the-art arbitration logic the author could find reported in the literature. The generated arbiter implemented in a single chip is fast enough in 0.25ьm CMOS technology to achieve terabit switching with a single chip computer network switch. Moreover, this arbiter is applicable to crossbar (Xbar) arbitration logic. The generated Xbar, customized according to user specifications, provides multiple communication paths among masters and slaves. As the number of transistors on a single chip increases rapidly, there is a productivity gap between the number of transistors available in a chip and the number of transistors per hour a chip designer designs. One solution to reduce this productivity gap is to increase the use of Silicon Intellectual Property (SIP) cores. However, a SIP core should be customized before being used in a system different than the one for which it was designed. Thus, to reconfigure the SIP core, either an engineer must spend significant effort altering the core by hand or else an enhanced CAD tool can automatically customize the core according to customer specifications. In this thesis, we present SIP generator tools for arbiter and Xbar generation. First, we introduce a Round-robin Arbiter Generator (RAG). The RAG can generate a hierarchical Bus Arbiter (BA) which is faster than all known previous approaches. RAG can also generate a hierarchical Switch Arbiter (SA) which is faster than all known previous approaches. Using a 0.25ьm TSMC standard cell library from LEDA Systems, we show the arbitration time of a 32x32 SA and demonstrate that our SA meets the time constraint to achieve terabit throughput. Furthermore, using a novel token-passing hierarchical arbitration scheme, our 32x32 SA performs better than the Ping-Pong Arbiter and Programmable Priority Encoder by factors of 1.8X and 2.3X, respectively, with less power dissipation. Finally, we present an Xbar switch Generator (X-Gt) tool that automatically configures a crossbar for a multiprocessor System-on-a-Chip (SoC). An Xbar is generated in Register Transfer Level (RTL) Verilog HDL.

The VLSI implementation complexity of a low density parity check (LDPC) decoder is largely influenced by the interconnect and the storage requirements. This dissertation presents the decoder architectures for regular and irregular LDPC codes that provide substantial gains over existing academic and commercial implementations. Several structured properties of LDPC codes and decoding algorithms are observed and are used to construct hardware implementation with reduced processing complexity. The proposed architectures utilize an on-the-fly computation paradigm which permits scheduling of the computations in a way that the memory requirements and re-computations are reduced. Using this paradigm, the run-time configurable and multi-rate VLSI architectures for the rate compatible array LDPC codes and irregular block LDPC codes are designed. Rate compatible array codes are considered for DSL applications. Irregular block LDPC codes are proposed for IEEE 802.16e, IEEE 802.11n, and IEEE 802.20. When compared with a recent implementation of an 802.11n LDPC decoder, the proposed decoder reduces the logic complexity by 6.45x and memory complexity by 2x for a given data throughput. When compared to the latest reported multi-rate decoders, this decoder design has an area efficiency of around 5.5x and energy efficiency of 2.6x for a given data throughput. The numbers are normalized for a 180nm CMOS process. Properly designed array codes have low error floors and meet the requirements of magnetic channel and other applications which need several Gbps of data throughput. A high throughput and fixed code architecture for array LDPC codes has been designed. No modification to the code is performed as this can result in high error floors. This parallel decoder architecture has no routing congestion and is scalable for longer block lengths. When compared to the latest fixed code parallel decoders in the literature, this design has an area efficiency of around 36x and an energy efficiency of 3x for a given data throughput. Again, the numbers are normalized for a 180nm CMOS process. In summary, the design and analysis details of the proposed architectures are described in this dissertation. The results from the extensive simulation and VHDL verification on FPGA and ASIC design platforms are also presented.

Collective Communication Operations are widely used in MPI applications and play an important role in their performance. Hence, various projects have focused on optimization of collective communications for various kinds of parallel computing environments including LAN settings, heterogeneous networks and most recently Grid systems. The distinguishing factor of Grids from all the other environments is heterogeneity of hosts and network, and dynamically changing resource characteristics including load and availability. The first part of the thesis develops a solution for MPI broadcast (one-to-many) on Grids. Some current strategies take into consideration static information about network topology for determining an efficient broadcast tree for Grids. Some other strategies take into account only transient network characteristics. We combined both these strategies and cluster the network dynamically on the basis of link bandwidths. Given a set of network parameters we use Simulated Annealing (SA) to obtain the best schedule. Also, we can time tune individual. SAs, to adapt the solution finding process, on the basis of estimated available times before next broadcast invocations in the application. We also developed software architecture for updation of schedules. We compared our algorithm with the earlier approaches under loaded network conditions, and obtained average performance improvement of 20%. The second part of the thesis extends the work for MPI all gather (many-to-many) operation. Current popular techniques consider strict hierarchical schemes for this operation, wherein from each cluster a representative (or coordinator) node is chosen, and inter cluster communication is done through these representative nodes. This is non optimal as inter cluster communication is usually on high capacity links that can sustain more than one transfer with the same through- put. We developed a cluster based and incremental heuristic algorithm for allgather on Grids. We compared the time taken by allgather schedules determined by this algorithm with current popular implementations. We also compared our algorithm with a strategy where allgather is constructed from a set of broadcast trees. We obtained average performance improvement of 67% over existing strategies.

No description available.

The word expropriation is used in South Africa to describe the process whereby a public authority or institution takes property from a private person for public purposes against payment of compensation. The current Act regulating expropriations in South Africa is known as the Expropriation Act 63 of 1975. However, it has three primary inconsistencies with the Constitution. Firstly it predates the Constitution - therefore, it does not infuse the values of equality, human dignity and the achievement of freedom. Secondly it is not consistent with comparable modem statutes elsewhere in the world. The last issue is that this Act is inconsistent with the Constitution in the sense that the Act only provides for expropriation for public purposes and the Constitution provides for expropriation in the public interest as well as for a public purpose. For these reasons it is crucial to establish a new legislative framework. In an attempt to rectify the above difficulties, an expropriation policy and a draft Bill were introduced. The primary purpose of the Bill is to harmonise the considerable amount of legislation in South Africa on the subject of expropriation, and to fill the gaps of the current Act. However, the new proposed Bill was referred back to cabinet as it had various difficulties. According to newspaper commentators, one of these reasons was that market value would not be used when determining the amount of compensation. This is not true, as market value is one of the listed factors in section 25(3) of the Constitution, and it is provided for in the Bill. Another reason was that the role of the courts will also be restricted in the new Bill. Parties will no longer be able to refer disputes concerning the amount of compensation to court. Once again this is not true, the courts role is only restricted in the sense that it would no be able to determine the amount of compensation as provided for in the Constitution, but will only be allowed to approve or decline the amount the Minister determined. This is one of the aspects that may be debatable constitutionally. After an in-depth study of the proposed Bill, the author came to the conclusion that there are actually only three aspects that might be unconstitutional namely; the definition of public interest which is to be included that widens the capacity to expropriate; departure from the notice procedure; and the fact that the courts may no longer determine the amount of compensation, but only approve or decline. Expropriation is one of the most important tools to speed up land reform in South Africa, and it is, therefore, of the utmost importance that the procedure must take place in a fair, equitable and constitutional manner. The purpose of this study will be to identify the aspects which result in expropriations that is not done on this basis, to scrutinize them and to make recommendations to these aspects. / Thesis (LL.M. (Law)--North-West University, Potchefstroom Campus, 2009.

The word expropriation is used in South Africa to describe the process whereby a public authority or institution takes property from a private person for public purposes against payment of compensation. The current Act regulating expropriations in South Africa is known as the Expropriation Act 63 of 1975. However, it has three primary inconsistencies with the Constitution. Firstly it predates the Constitution - therefore, it does not infuse the values of equality, human dignity and the achievement of freedom. Secondly it is not consistent with comparable modem statutes elsewhere in the world. The last issue is that this Act is inconsistent with the Constitution in the sense that the Act only provides for expropriation for public purposes and the Constitution provides for expropriation in the public interest as well as for a public purpose. For these reasons it is crucial to establish a new legislative framework. In an attempt to rectify the above difficulties, an expropriation policy and a draft Bill were introduced. The primary purpose of the Bill is to harmonise the considerable amount of legislation in South Africa on the subject of expropriation, and to fill the gaps of the current Act. However, the new proposed Bill was referred back to cabinet as it had various difficulties. According to newspaper commentators, one of these reasons was that market value would not be used when determining the amount of compensation. This is not true, as market value is one of the listed factors in section 25(3) of the Constitution, and it is provided for in the Bill. Another reason was that the role of the courts will also be restricted in the new Bill. Parties will no longer be able to refer disputes concerning the amount of compensation to court. Once again this is not true, the courts role is only restricted in the sense that it would no be able to determine the amount of compensation as provided for in the Constitution, but will only be allowed to approve or decline the amount the Minister determined. This is one of the aspects that may be debatable constitutionally. After an in-depth study of the proposed Bill, the author came to the conclusion that there are actually only three aspects that might be unconstitutional namely; the definition of public interest which is to be included that widens the capacity to expropriate; departure from the notice procedure; and the fact that the courts may no longer determine the amount of compensation, but only approve or decline. Expropriation is one of the most important tools to speed up land reform in South Africa, and it is, therefore, of the utmost importance that the procedure must take place in a fair, equitable and constitutional manner. The purpose of this study will be to identify the aspects which result in expropriations that is not done on this basis, to scrutinize them and to make recommendations to these aspects. / Thesis (LL.M. (Law)--North-West University, Potchefstroom Campus, 2009.

Large-eddy simulation (LES) and unsteady Reynolds-averaged Navier-Stokes (URANS) calculations have been performed to investigate the effects of different mathematical models for scalar variance and its dissipation rate as applied to both a non-reacting bluff-body turbulent flow and an extension to a reacting case. In the conserved scalar formalism, the mean value of a thermo-chemical variable is obtained through the PDF-weighted integration of the local description over the conserved scalar, the mixture fraction. The scalar variance, one of the key parameters for the determination of a presumed β-function PDF, is obtained by solving its own transport equation with the unclosed scalar dissipation rate modelled using either an algebraic expression or a transport equation. The proposed approach is first applied to URANS and then extended to LES. Velocity, length and time scales associated with the URANS modelling are determined using the standard two-equation k-ε transport model. In contrast, all three scales required by the LES modelling are based on the Smagorinsky subgrid scale (SGS) algebraic model. The present study proposes a new algebraic and a new transport LES model for the scalar dissipation rate required by the transport equation for scalar variance, with a time scale consistent with the Smagorinsky SGS model.

L'accroissement d'efficacite des réseaux d'interconnexion et la vulgarisation des machines multiprocesseurs permettent la réalisation de machines parallèles a mémoire distribuée de faible coût: les grappes de multiprocesseurs. Elles nécessitent l'exploitation à la fois du parallélismeà grain fin, interne à un multiprocesseur offert par la multiprogrammation légère, et du parallélisme à gros grain entre les différents multiprocesseurs. L'exploitation simultanée de ces deux types de parallélisme exige une méthode de communication entre les processus légers qui ne partagent pas le mêmme espace d'adressage. Le travail de cette thèse porte sur le problème de l'Intégration de la multiprogrammation légère et des communications sur grappes de multiprocesseurs symétriques (SMP). II porte plus précisément sur evaluation et le reglage du noyau exécutif ATHAPASCAN-0 sur ce type d'architecture. ATHAPASCAN-0 est un noyau exécutif, portable, développé au sein du projet APACHE (CNRS-INPG-INRIA-UJF), qui combine la multiprogrammation légère et la communication par échange de messages. La portabilité est assurée par une organisation en couches basée sur les standards POSIX threads et MPI largement répandus. ATHAPASCAN-0 étend le modèle de réseau statique de processus «lourds» communicants tel que MPI, PVM, etc,à celui d'un réseau dynamique de processus légers communicants. La technique de base est la multiprogrammation lègere des communications et des calculs. La progression des communications exige la scrutation de état du reseau et l'enchainement des opérations de transferts. L'efficacité repose sur la minimisation de ces opérations. De plus, l'emploi de multiprocesseurs ajoute des problèmes spécifiques dus à l'apparition d'un parallélisme réel entre calcul et communication. Ces problèmes sont présentés et des solutions sont proposées pour l'environnement ATHAPASCAN-0. Ces solutions sont évaluées sur des grappes de multiprocesseurs. / The continuous price reduction for commodity PC multiprocessors and the availability of fast network interfaces have made cluster of multiprocessors an attractive low-price alternative to build parallel systems. Multiprocessor clusters offer two levels of parallelism: a fine grain parallelism inside a single multiprocessor and a coarse grain among them. A mechanism must be provided to exploit both levels of parallelism simultaneously. This requires to provide communications between threads belonging to different addresses spaces. This dissertation addresses the problem of integrating threads and communications on ATHAPASCAN-0 run time system. ATHAPASCAN-0 is a portable run time for cluster of multiprocessors developed as part of the APACHE project (CNRS-INPG-INRIA-UJF). Portability is achieved by a layered organization based on standards like POSIX threads and MPI. The ATHAPASCAN-0 run time system extends the heavy-weight process communication model of message passing libraries such as MPI, PVM, etc, into a lighter dynamic network of communicating threads. Multiprogramming is the key concept used. Communication progress is based on a network polling basis to handle incoming messages and to deliver outgoing communications requests. Performance is strongly dependent on the way these operations are implemented. Additionally, multiprocessors introduce some programming problems like overhead of cache coherency mechanisms, method of managing concurrent accesses and efficient mutex locking to avoid unnecessary context switching. These problems are analyzed and solutions are implemented in the ATHAPASCAN-0 run time system. An evaluation of these solutions is performed on a cluster of multiprocessors.