Proefschrift Universiteit van Amsterdam. / Met lit. opg. - Met samenvatting in het Engels.

Thesis (Doctoral)--Ludwig-Maximilians-Universität zu München, 1980.

Proefschrift Universiteit van Amsterdam. / Met lit. opg. - Met samenvatting in het Engels.

The paradoxical nature of society leads to great dualities in the study of motion and space, creating conflicting relationships. The role of the architectural design is to facilitate these motions to become a stage for the spectacle in its immediate context. The dissertation presents an architectural proposal that addresses the notion of duality. By identifying the possibilities within a liminal context, an architectural narrative creates scenarios as a possible response. The author investigates the manifestation of multiple programmes, a leather workshop, bakery and bar within the South African urban context of Pretoria West. The architectural exploration aims to enrich public life in a liminal space on the periphery of the city. Challenges associated with the typology of duality are addressed through the integration with the immediate context to ensure its sustainability. The aim is to celebrate the edge condition and the spaces commonly overlooked. / Dissertation MArch(Prof)-University of Pretoria, 2012. / Architecture / MArch(Prof) / Unrestricted

Academisch proefschrift--Amsterdam. / Bibliography: p. 147.

Thesis (doctoral)--Uppsala universitet, 1996. / Includes bibliographical references (p. 226-231).

Academisch proefschrift--Amsterdam. / Bibliography: p. 147.

The aim of the dissertation was to design a realistic, low-complexity non-binary (NB) low density parity check (LDPC) coded space-time-frequency (STF) coded multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) system with an iterative joint decoder and detector structure at the receiver. The goal of the first part of the dissertation was to compare the performance of different design procedures for NB-LDPC codes on an additive white Gaussian noise (AWGN) channel, taking into account the constraint on the code length. The effect of quantisation on the performance of the code was also analysed. Different methods for choosing the NB elements in the parity check matrix were compared. For the STF coding, a class of universal STF codes was used. These codes use linear pre-coding and a layering approach based on Diophantine numbers to achieve full diversity and a transmission rate (in symbols per channel use per frequency) equal to the number of transmitter antennas. The study of the system considers a comparative performance analysis of di erent ST, SF and STF codes. The simulations of the system were performed on a triply selective block fading channel. Thus, there was selectivity in the fading over time, space and frequency. The effect of quantisation at the receiver on the achievable diversity of linearly pre-coded systems (such as the STF codes used) was mathematically derived and verified with simulations. A sphere decoder (SD) was used as a MIMO detector. The standard method used to create a soft-input soft output (SISO) SD uses a hard-to-soft process and the max-log-map approximation. A new approach was developed which combines a Hopfield network with the SD. This SD-Hopfield detector was connected with the fast Fourier transform belief propagation (FFT-BP) algorithm in an iterative structure. This iterative system was able to achieve the same bit error rate (BER) performance as the original SISO-SD at a reduced complexity. The use of the iterative Hopfield-SD and FFT-BP decoder system also allows performance to be traded off for complexity by varying the number of decoding iterations. The complete system employs a NB-LDPC code concatenated with an STF code at the transmitter with a SISO-SD and FFT-BP decoder connected in an iterative structure at the receiver. The system was analysed in varying channel conditions taking into account the effect of correlation and quantisation. The performance of different SF and STF codes were compared and analysed in the system. An analysis comparing different numbers of FFT-BP and outer iterations was also done. AFRIKAANS : Die doel van die verhandeling was om ’n realistiese, lae-kompleksiteit nie-binˆere (NB) LDPC gekodeerde ruimte-tyd-frekwensie-gekodeerde MIMO-OFDM-sisteem met iteratiewe gesamentlike dekodeerder- en detektorstrukture by die ontvanger te ontwerp. Die eerstem deel van die verhandeling was om die werkverrigting van verskillende ontwerpprosedures vir NB-LDPC kodes op ’n gesommeerde wit Gausruiskanaal te vergelyk met inagneming van die beperking op die lengte van die kode. Verskillende metodes om die nie-bineêre elemente in die pariteitstoetsmatriks te kies, is gebruik. Vir die ruimte-tyd-frekwensiekodering is ’n klas universele ruimte-tyd-frekwensiekodes gebruik. Hierdie kodes gebruik lineêre pre-kodering en ’n laagbenadering gebaseer op Diofantiese syfers om volle diversiteit te bereik en ’n oordragtempo (in simbole per kanaalgebruik per frekwensie) gelyk aan die aantal senderantennes. Die studie van die sisteem oorweeg ’n vergelykende werkverrigtinganalisie van verskillende ruimte-tyd-, ruimte-freksensie- en ruimte-tyd-frekwensiekodes. Die simulasies van die sisteem is gedoen op ’n drievoudig selektiewe blokwegsterwingskanaal. Daar was dus selektiwiteit in die wegsterwing oor tyd, ruimte en frekwensie. Die effek van kwantisering by die ontvanger op die bereikbare diversiteit van lineêr pre-gekodeerde sisteme (soos die ruimte-tyd-frekwensiekodes wat gebruik is) is matematies afgelei en bevestig deur simulasies. ’n Sfeerdekodeerder (SD) is gebruik as ’n MIMO-detektor. Die standaardmetode wat gebuik is om ’n sagte-inset-sagte-uitset (SISO) SD te skep, gebruik ’n harde-na-sagte proses en die maksimum logaritmiese afbeelding-benadering. ’n Nuwe benadering wat ’n Hopfield-netwerk met die SD kombineer, is ontwikkel. Hierdie SD-Hopfield-detektor is verbind met die FFT-BP-algoritme in iteratiewe strukture. Hierdie iteratiewe sisteem was in staat om dieselfde bisfouttempo te bereik as die oorspronklike SISO-SD, met laer kompleksiteit. Die gebruik van die iteratiewe Hopfield-SD en FFT-BP-dekodeerdersisteem maak ook daarvoor voorsiening dat werkverrigting opgeweeg kan word teen kompleksiteit deur die aantal dekodering-iterasies te varieer. Die volledige sisteem maak gebruik van ’n QC-NB-LDPC-kode wat met ’n ruimte-tyd-frekwensiekode by die sender aaneengeskakel is met ’n SISO-SD en FFT-BP-dekodeerder wat in ’n iteratiewe struktuur by die ontvanger gekoppel is. Die sisteem is onder ’n verskeidenheid kanaalkondisies ge-analiseer met inagneming van die effek van korrelasie en kwantisering. Die werkverrigting van verskillende ruimte-frekwensie- en ruimte-tyd-frekwensiekodes is vergelyk en in die sisteem ge-analiseer. ’n Analise om ’n wisselende aantal FFT-BP en buite-iterasies te vergelyk, is ook gedoen. Copyright / Dissertation (MEng)--University of Pretoria, 2010. / Electrical, Electronic and Computer Engineering / unrestricted

The general body of academic knowledge on the commercial development of smaller towns is in its infancy. Yet its inherent potential is well perceived from a development and market perspective. Shopping centre development could have an important function in getting products and services to the marketplace in an economical way. Furthermore, it could have a very significant socio-economic impact in the central business district (CBD). Although such a shopping centre will surely create new businesses, employment and production opportunities for local businesses it is of importance to first determine the financial viability and impact of the new development on existing businesses. Developers and researchers often approach the subject of shopping centre development from different perspectives. The research output is often of limited impact as the critical link between demographical analysis and financial viability is not made. Researchers are usually excluded from the physical establishment, rental structures, tenant mix, design, cost of construction, return on investment, funding and future management of the proposed new shopping centre project. Linking demographic assessment and financial viability is a critical output of this study. Bethlehem and its district are quite unique in a number of ways, especially regarding the presence of a large farming community. Bethlehem provides goods and services to residents of Bethlehem, Clarens, Kestell, Harrismith, Heilbron, Paul Roux, Petrus Steyn, Reitz, Senekal and Warden. The main shopping activity occurs in the CBD of Bethlehem and its surrounding areas. Bethlehem only has one major shopping centre (the Metropolitan Centre) that provides goods and services for the people in the surrounding area. This causes an over concentration in the CBD and too much traffic in an already limited space. There is a high need for Bethlehem to provide a bigger shopping centre for the citizens of the town, as well as the surrounding areas. This study investigates the need for a new shopping centre in Bethlehem and will determine whether a new shopping centre will be viable within the area The empirical study revealed that approximately half of the respondents are not satisfied with the current shopping centres in Bethlehem. A greater amount of respondents felt that the shopping centres do not offer enough parking. The study revealed that, from a consumer point of view, there is definitely a need for a new shopping centre in Bethlehem and that there is a gap of approximately 12 892m² GLA (Gross leasable area). However, this was determined before the opening of the new Dihlabeng Mall. The Dihlabeng Mall occupies 24 142m², therefore an oversupply is already taken place. / MArt et Scien (Urban and Regional Planning), North-West University, Potchefstroom Campus, 2013

The general body of academic knowledge on the commercial development of smaller towns is in its infancy. Yet its inherent potential is well perceived from a development and market perspective. Shopping centre development could have an important function in getting products and services to the marketplace in an economical way. Furthermore, it could have a very significant socio-economic impact in the central business district (CBD). Although such a shopping centre will surely create new businesses, employment and production opportunities for local businesses it is of importance to first determine the financial viability and impact of the new development on existing businesses. Developers and researchers often approach the subject of shopping centre development from different perspectives. The research output is often of limited impact as the critical link between demographical analysis and financial viability is not made. Researchers are usually excluded from the physical establishment, rental structures, tenant mix, design, cost of construction, return on investment, funding and future management of the proposed new shopping centre project. Linking demographic assessment and financial viability is a critical output of this study. Bethlehem and its district are quite unique in a number of ways, especially regarding the presence of a large farming community. Bethlehem provides goods and services to residents of Bethlehem, Clarens, Kestell, Harrismith, Heilbron, Paul Roux, Petrus Steyn, Reitz, Senekal and Warden. The main shopping activity occurs in the CBD of Bethlehem and its surrounding areas. Bethlehem only has one major shopping centre (the Metropolitan Centre) that provides goods and services for the people in the surrounding area. This causes an over concentration in the CBD and too much traffic in an already limited space. There is a high need for Bethlehem to provide a bigger shopping centre for the citizens of the town, as well as the surrounding areas. This study investigates the need for a new shopping centre in Bethlehem and will determine whether a new shopping centre will be viable within the area The empirical study revealed that approximately half of the respondents are not satisfied with the current shopping centres in Bethlehem. A greater amount of respondents felt that the shopping centres do not offer enough parking. The study revealed that, from a consumer point of view, there is definitely a need for a new shopping centre in Bethlehem and that there is a gap of approximately 12 892m² GLA (Gross leasable area). However, this was determined before the opening of the new Dihlabeng Mall. The Dihlabeng Mall occupies 24 142m², therefore an oversupply is already taken place. / MArt et Scien (Urban and Regional Planning), North-West University, Potchefstroom Campus, 2013