• Analyses & Alternatives
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• v.2 no.2
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• pp.93-110
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• 2018

Due to its speciality, Johannesburg has drawn wide attention from the international academia, which the existing urban theory cannot easily explain. This paper focuses on the spatial pattern of Johannesburg, and finds that it is highly fragmented: first North-South Division due to apartheid and gold mining, secondly, the continuous sprawl due to population densification, and thirdly formation of city-region due to the fill-in spatial policy. The fragmented spatial pattern undermines the social integration and weakens the potential economic sustainability, which make the balanced multi-core spatial pattern inevitable under the influence of the international planning thought. The Johannesburg's spatial transformation comes not only from social integration, but also from the development vison of world-class status of an African city. In reality, since the collapse of apartheid, the municipal government has released series of strategic planning in different executive phase. These different plannings unanimously focus on the world class status although since 2008, the social inclusiveness is more emphasized. Thus, Johannesburg implements some spatial policies, as promoting the corridor of freedom, identifying the key nodes in the city then developing with high density, implementing the in-filling policy, managing the urban growth boundary, effectively preserving the natural system. However, the industrial structure in Johannesburg is already quite high-ended which cannot produce many jobs and also require much investment in advanced infrastructure. Thus, the strategic goals of world-class status of an African city and social inclusiveness which really need widely shared public services to some extent are in tension. After evaluation, we can see that spatial transformation is quite limited. Obviously spatial transformation largely depends on the social-economy. The population is still in flow. In this sense Johannesburg must energetically support the employment-based industry, effectively control the spatial sprawl and carry out institutional innovation which further incentive investment, gradually build an integrated regional governance. In general, how Johannesburg combines globalization and its own condition is still worth thinking in both theory and practice.

• Journal of Chest Surgery
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• v.50 no.4
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• pp.295-297
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• 2017

A 27-year-old man was admitted with a penetrating injury at the mid-manubrium. Computed tomographic (CT) angiography showed a f illing def ect in the aortic arch. This was evaluated as a sign of injury and the patient underwent an emergency operation. No active bleeding or clot was f ound in the mediastinum during the operation. The laceration point was between the innominate and the left carotid artery posteriorly. The injury was approached using hypothermic circulatory arrest. Aortotomy and exploration showed a 2-cm-long full-thickness aortic injury with an overlying clot. A filling defect on angiography as a sign of a penetrating arch injury has never been reported previously, but was the main pathological finding on CT angiography in our case. The aorta is a high-pressure system and injuries to it should be treated aggressively.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.52-59
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• 2013

The use of economic incentives to improve H&S performance in the construction industry in general, has been investigated by various scholars. However, few studies have looked at the impact of economic incentives on construction clients especially in the developing world. Therefore it was necessary to investigate specifically the impact of the economic incentive on client's H&S performance. Economic incentives are considered to be a proactive way of improving H&S performance. The investigation was conducted using a Delphi technique to determine the impact significance of the economic incentive or disincentive on construction clients' H&S performance. Findings from the study were that the economic factor had critical impact significance on clients' H&S performance. Further clients were 'very likely to' implement various H&S elements as a result of the economic incentive and disincentive. The paper will report on the findings from an analysis of impact significance of the economic incentives on clients. It will underscore the point that economic incentives or disincentives on construction clients are necessary to encourage them to actively participate in H&S performance improvement.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.647-652
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• 2011

Developments in the teaching of the National Diploma in Building students should be geared towards meeting the needs of the construction industry in South Africa. These needs are usually in the form of skills and knowledge required to resolve thorny issues encountered in practice. The lack of capacity in the construction industry needs to be addressed from the basis of ensuring that the education system caters for both mature entry and matriculation entry students. The paper looks at a comparison in performance between mature entry and matriculation (just finish High School) entry students focusing on the National Diploma in Building students at the University of Johannesburg. The paper will make a comparison between those students who work first before enrolling for their first year National Diploma in Building and those who are directly from high school. Cooperative education involves training and systematically developing students through the acquisition of the requisite skills, attitudes, values and knowledge required to adequately perform in their chosen careers. The paper describes the problems and experiences that have been encountered by both mature and matriculation entry students in their three years of study which affects their performance. The paper will then look at the value of prior experience in enabling students to finish their National Diploma in Building within a three year period. The paper closes with some recommendations for the future.

• The Journal of Art Theory & Practice
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• no.10
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• pp.63-84
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• 2010

This essay examines how the figure of Liberty has been refashioned in the streets of post-apartheid South Africa, addressing three public art works installed in Johannesburg over the past decade: Reshada Crouse's oil painting Passive Resistance, Marlene Dumas' tapestry The Benefit of the Doubt and William Kentridge's and Gerhard Marx's sculpture Firewalker. Even as these monumental works all reprise Delacroix's Liberty on the Barricades-an icon of the city street and its revolutionary barricades-so too this trio of Liberties have become mere phantoms of their vaunted archetype. Haunted specters, they quarrel with the mythologized chimera of Liberty, taking issue with the fraught tradition of pinning regime change onto the body of the female nude. Drawing instead on South African histories of women's resistance, in which female nudity has been repeatedly marshaled as a form of dissent, the Liberties circling Johannesburg hybridize their European template with local traditions of female political opposition to colonial and postcolonial male authority.

• Geomechanics and Engineering
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• v.28 no.1
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• pp.35-48
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• 2022

The effect of discrete polypropylene fibre reinforcement on shear strength parameters, tensile properties and isotropic index of stabilized compacted residual subgrade was investigated. Composites of compacted subgrade were developed from polypropylene fibre dosage of 0%, 1%, 2.5% and 4% and 3% cement binder. Saturated compacted soil benefited from incremental fibre dosage, the mobilized friction coefficient increased to a maximum at 2.5% fibre dosage from 0.41 to 0.58 and the contribution due to further increase in fibre dosage was marginal. Binder stabilization increased the degree of isotropy for unreinforced soil at lower fibre dosage of 1% and then decreased with higher fibre dosage. Saturation of 3% binder stabilized soil decreased the soil friction angle and the degree of isotropy for both unstabilized and binder stabilized soil increased with fibre dosage. The maximum tensile stress of 3% binder stabilized fibre reinforced residual soil was 3-fold that of 3% binder stabilized unreinforced soil. The difference in computed and measured maximum tensile and tangential stress decreased with increase in fibre dosage and degree of stabilization and polypropylene fibre reinforced soil met local and international criteria for road construction subgrade.

• Geomechanics and Engineering
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• v.36 no.1
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• pp.39-50
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• 2024

Bitumen and high-quality subangular aggregates, the two principal materials used for asphalt concrete construction, are finite and expensive materials. The general availability of crumb rubber and naturally occurring aggregates of different shapes, especially flat and elongated shapes, indicates that they are feasible alternative materials for expanding the volume of bitumen and utilizing a wider range of aggregate shapes for the development of asphalt concrete, with an associated environmental benefit. The study investigated the effect of adding up to 15% crumb rubber and aggregates sorted into different groups, i.e., rounded, elongated, flat, and their combinations, on the rheological and mechanical properties and durability of 50/70 of hot-mix asphalt pavement. The addition of crumb rubber decreased ductility and penetration but increased the softening point. For a 5.5% bitumen content, asphalt concrete briquettes consisting of 7% crumb rubber and three types of aggregate shapes, i.e., 100% rounded, a mix of 75% rounded and 25% elongated, and a mix of 75% rounded, 15% elongated and 10% flat, were associated with high Marshall stability and indirect tensile strength as well as low lateral deformation due to their high solidity and moderate angularity ratio. Also, the addition of 7% crumb rubber resulted in a significant improvement in the tensile strength ratio and rebound strain of briquettes consisting of 75% rounded and 25% elongated aggregates and those with 75% rounded, 15% elongated and 10% flat aggregates. In relation to the parameters investigated, the three groups of briquettes met some of the local (South Africa) requirements for the surface course and base course of low traffic volume roads.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2003.05a
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• pp.37-62
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• 2003

대체에너지는 지속 가능한 에너지공급원으로 21세기 유망산업으로 등장, 환경문제와 에너지 안보를 동시에 충족, 수출전략산업으로 육성할 필요가 증대, Johannesburg의 지속 가능발전정상회의(WSSD) 재생에너지 비중 확대 논의(미국과 EU의 대립) 대체에너지 공급 목표 설정에는 실패, 대체에너지의 위상 크게 향상(중략)

• Journal of the Korean housing association
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• v.26 no.6
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• pp.27-34
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• 2015

This paper provides an overview of the experiences of the people's housing process (PHP) in South Africa. The discussion is done against the backdrop of the different outcomes of the government public housing provision initiative, commonly known as the Reconstruction and Development Programme (RDP) that directly produced more than three million subsidized housing to formerly segregated and disadvantaged populations. Notwithstanding the huge success in providing the much needed accommodation to such previously marginalized communities, the over-reliance on direct provision has the PHP ostensibly less impactful in housing delivery. Against the backdrop of the soaring housing backlogs, concerns with housing quality and the financial difficulties as well as the shrinking fiscal space; the article recommends improved support of the PHP. This can be achieved by the adoption of innovations that make land and minimal infrastructure and services available to the urban poor and to support their initiatives of self-building.

• Journal of Power Electronics
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• v.18 no.6
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• pp.1912-1919
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• 2018

The output capacitance of power semiconductor devices is important in determining the switching losses and in the operation of some resonant converter topologies. Thus, it is important to be able to accurately determine the output capacitance of a particular device operating at elevated power levels so that the contribution of the output capacitance discharge to switch-on losses can be determined under these conditions. Power semiconductor switch manufacturers usually measure device output capacitance using small-signal methods that may be insufficient for power switching applications. This paper shows how first principle methods are applied in a novel way to obtain more relevant large signal output capacitances of Gallium-Nitride (GaN) FETs using the drain-source voltage transient during device switch-off numerically. A non-linear capacitance for an increase in voltage is determined with good correlation. Simulations are verified using experimental results from two different devices. It is shown that the large signal output capacitance as a function of the drain-source voltage is higher than the small signal values published in the data sheets for each of the devices. It can also be seen that the loss contribution of the output capacitance discharging in the channel during switch-on correlates well with other methods proposed in the literature, which confirms that the proposed method has merit.