63 research outputs found
Op soek na\u27n Mediabestel vir Suid·Afrika: \u27n Voorlopige antwoord aan Keyan Tomaselli
No full textCOMMUNICARE encourages the scientific debate. Our last contribu tion is published in response to the article of Tomaselli & Louw In 9(1), who questioned some of the predie tions regarding post-apartheid media In an earlier article by the author pub lished In 8(1). These are his repiles... Prof Keyan Tomaselli, Director of the Cultural Studies Unit at the University of Natal (Durban), is without doubt one of most prolific writers in the field of South African media and communication studies. This is not a matter of c tention; what is at stake in this review article Is the way in which Tomaselll deals with statements and facts in his pub lications. It is argued that Tomaselli Is prone to state a debatable point as a "scientific fact" and then proceeds to build a whole theoretical argument on this and similar "facts". It is fur ther argued that his article: \u27Vrye Weekblad\u27 and post-apartheld mania; what to do with the press? is a case In point
Ethical Procedures? A Critical Intervention: The sacred, the profane, and the planet
No full textIssues relating to ethical clearance, how these procedures relate to very different ontologies, ways of making sense,conditions of existence, and the ideological implications thereof are critically discussed. Written as an invited intervention, the author takes readers through a variety of paradigms: indigenous approaches involving the sacred and the profane, instrumentalization of research; multispeciesism and research as a lived practice. Comments are offered on the nature of science and some questions are posed on the contradictions of ethical practices that readers encounter. The method is eclectic, read through a Peirceian pragmatism, and the outcome proposes relationality rather than the inevitability of discrete findings. Some conclusions are offered on the geographical distribution of populations sampled.</jats:p
A self-reflexive analysis of Communicare: Inter-paradigmatic repositioning
No full textThis partly autoethnographical account of my experiences as an author, editor and researcheroffers an experiential framework with which to make sense of publishing in the contemporaryera, governed as it is by neoliberal managerialist principles that tend to reduce activities tomeasureable units so as to render academic disciplines comparable. This is the context withinwhich Communicare is repositioning itself in communication and media studies, situated as it isbetween positivist communication science and interpretivist critical theory. Historical elements ofthe journal are examined via the author’s long-term association with it. The article ends with anexamination of the problems that scholarly work faces when universities measure finite productsat the expense of processes
CNN vs. SIFT for Image Retrieval: Alternative or Complementary?
No full textIn the past decade, SIFT is widely used in most vision tasks such as image retrieval. While in recent several years, deep convolutional neural networks (CNN) features achieve the state-of-the-art performance in several tasks such as image classification and object detection. Thus a natural question arises: for the image retrieval task, can CNN features substitute for SIFT? In this paper, we experimentally demonstrate that the two kinds of features are highly complementary. Following this fact, we propose an image representation model, complementary CNN and SIFT (CCS), to fuse CNN and SIFT in a multi-level and complementary way. In particular, it can be used to simultaneously describe scene level, object-level and point-level contents in images. Extensive experiments are conducted on four image retrieval benchmarks, and the experimental results show that our CCS achieves state-of-the-art retrieval results.CPCI-S(ISTP)[email protected]; [email protected]; [email protected]; [email protected]; [email protected]
Encoding/Decoding, the transmission model and a court of law
No full textAbstract: Stuart Hall’s encoding/decoding model is discussed in terms of CS Peirce’s theory of the interpreter and interpretant. This historical semiotic window frames an example to which the Hall model was applied in South Africa to oppose a military dirty tricks campaign that involved a Supreme Court case brought against the Minister of Defence by the End Conscription Campaign (ECC) requiring him to cease his disinformation against the ECC. The Minister’s own expert had proposed a transmission model of communication that was defeated by the Peirce-Hall combination. The author argues that the model can be massively strengthened when combined with Peirceian semiotics
‘Twelve Years Later: Second ASSAf report on Research Publishing in and from South Africa (2018)’: Some issues arising
No full textAbstract:Responding to the extraordinary challenges facing publication in the digital age is the holistic view taken by the Academy of Science of South Africa (ASSAf) on threats and opportunities that characterise this conjuncture. Twelve Years Later, researched by Wieland Gevers, Robin Crewe and Susan Veldsman on national publishing strategies, provides the ‘nuts ’n bolts’ that every researcher should know in order to navigate the changing environment.1 The Report examines both past and present. The first chapter reviews ASSAf’s 2006 report.2 Chapter 2 revisits the 2009 report on books. Chapter 3 details ASSAf’s Scholarly Publishing Programme between 2007 and 2018. How to enhance access of South African authors to global commercial publishers is discussed in Chapter 4. Chapter 5 deals with journal and book publishing, and Chapter 6 examines pitfalls and threats to good publishing practices. Outstanding problems are highlighted in Chapter 7. Chapter 8 offers recommendations. Appendices (45 pp) tabulate the hard data on which the study draws. These data showcase close correlations between the ASSAf qualitative evaluations and Department of Higher Education and Training (DHET) decisions. Significantly, ASSAf ratings and reviews of publishers closely align with the international Socio-economic and Natural Sciences of the Environment (SENSE) and the Norwegian Register for Scientific Journals, Series and Publishers ratings. The 2018 Report offers a detailed history useful for individual university policy planning, and implementation of monitoring mechanisms, and explains accreditation decisions. A basic cost–benefit analysis of the publication incentive system administered by DHET identifies residual problems. Notwithstanding these (see below), the statistics tabulated in Appendices by the Centre for Research, Evaluation, Science and Technology (CREST) at Stellenbosch University reveals that DHET has been very effective in encouraging publication. It has also acted as an inhibiting factor in author choice of predatory journals, although many thousands of articles still slipped through...
Formation of rings in a swirling gas flow
No full textThe main structure of this thesis is aimed to study the behaviour of a swirling air flow in a cylindrical chamber through experiments. Different tiny particles, water droplets and NaCl aerosol particles (μm and submicron scale), are adopted to trace the motion of air flow.In the preface, the background and motivation of this project are introduced. Inspired by the ring structures found in proto-planetary disks, we want to experimentally explore possible connections between angular momentum transport and flow structure.In the beginning part of this thesis, basic fluid dynamics and necessary models are introduced, for the convenience of the latter part of this thesis. A new parameter, coupling efficiency χ was introduced to characterize the coupling wellness between tracer particles and flow, specifically, in this experiment. We also list three examples of flow-particle coupling as supplementary materials, since they are related with this thesis’ topic.In the middle part, the detailed hardware setup and methods of this experiment are introduced. All of the important instrumentation information is listed, as well as the preparations and general experiment methods.In the following part, the experiment results are presented. We also conduct a COMSOL flow simulation, to give a rough idea on the flow velocity profile inside the chamber, though we don’t expect the accuracy of the simulation. The recorded images are processed with MATLAB for measurements. We have found that water droplets and NaCl aerosol particles are behaving differently as tracers, mainly, in the central flow. Besides, we also find continuous and random expanding rings emerging from the centre in water droplet experiments. These expanding rings are much more common in water droplet experiments than that of NaCl experiments. The flow structure and radial expansion speed of those expanding rings are measured with MATLAB.Finally, we have two conclusions based on what we’ve found. The first one is that, the larger water droplets are decoupled from the gas flow in the central flow region. The second one is that, with some assumptions, we have a hypothesis that the expanding rings we find are representing the separation of water droplets from the flow. This possibility is verified by comparing the radial drifting speed of particles from a theoretical model solved by COMSOL ODE module with our measurements. The results prove our hypothesis, given the assumptions. But the proof for the second conclusion isn’t comprehensive, which is a possible direction for future work. Additionally, we further propose that, if both of our conclusions hold, it means that the water droplets, which receive the angular momentum and decoupled from the gas, are drifting outward in the form of pulsed expanding rings. This conclusion could be described as "he who gains angular momentum shall expand like rings", and it’s useful in explaining the ring formation found in proto-planetary disks,In the last chapter, the main drawbacks and future improvements are discussed. Mainly, we lack a precise understanding on the flow’s velocity profiles, which could be improved by introducing more advanced measuring technologies into the experiment.本文主要通過實驗來研究在一個圓柱容器的旋轉氣流的動力學特徵。我們用兩種不同尺寸的示蹤顆粒：水霧（約微米尺寸）和氯化鈉（小於微米尺寸）顆粒作示蹤粒子來表徵氣流的運動。本文的前言部分是一個簡要的研究背景介紹。從原初行星盤中發現的環帶狀結構得到靈感，我們嘗試從實驗的角度去驗證角動量輸運和旋轉氣流所表徵出的結構是否有關聯。本文的第一部分將簡要介紹一些本文所將涉及到的流體力學理論和模型。本文提出一個參數χ用於表徵本文所述實驗中的示蹤粒子和氣流的耦合程度。需要注明的是，這個參數是專門為本實驗而優化的。本文也另外列舉了三個粒子-氣流耦合問題的例子，作與本實驗的參考。本文第二部分詳細介紹本文所述實驗的硬件搭建細節與實驗方法，包括所使用的儀器和測量設備的詳細參數。另外，一些準備工作和前序實驗也會順帶被提到。本文第三部分將會展示實驗結果。首先通過COMSOL的流體力學仿真，我們可以粗略瞭解容器旋轉氣流的速度場。雖然仿真結果未必準確，但仍不妨當作一個參考。隨後，本研究利用MATLAB來分析相機所記錄下來的氣流圖像。我們發現實驗中所采用的兩種不同的示蹤粒子表現出不同的與氣流的耦合程度，特別是在漩渦中心更加明顯。除此之外，我們還在所記錄的圖像中發現了連續但不規律性的環狀結構；并且這些環狀結構都會持續向外擴張。相較於以氯化鈉顆粒作示蹤粒子，此類結構在以水霧顆粒作示蹤粒子的實驗中更明顯。以MATLAB為工具，通過測量此類環狀結構的半徑變化，我們推測出這些環狀結構的徑向擴散速度。本文的結尾部分，我們得出兩個初步結論。第一個結論是，由於尺寸較大，水霧顆粒在漩渦中已經失去了與氣流的耦合性。第二個結論是，在一些假設作前提下，我們猜測（在水霧作示蹤粒子的實驗中）所觀察到的環狀結構正是失去與氣流耦合而被分離出的水霧顆粒。進一步研究，我們設計了一個簡化的顆粒-氣流耦合的動力學模型並通過COMSOL ODE模塊來求解顆粒在氣流中的理論漂移速度。通過計算，我們發現所觀察到的環狀結構的徑向速度與模型所推導出的示蹤粒子徑向漂移速度高度一致。但是，因這個理論模型中做出了許多假設以簡化複雜程度，故這個結論的證明與確認過程仍然存在不充分性。這也是未來後續工作一個需要補充的實驗方向。撇開上述不足之處，本文進一步指出，若兩個結論都成立，則表明在本實驗中，失去與氣流耦合性的水霧顆粒從旋轉氣體中得到了角動量，並以間隔性的環狀結構向外漂移。這個結論可以總結為，“但凡得到角動量的，必將以環狀結構向外擴散”。這個結論在解釋原初行星盤中的環狀結構可能會有一定意義。在本文的最後一部分，我們分析了本次實驗中的不足之處與缺陷。簡而言之，由於缺乏更精確的測量手段，我們對於氣流速度場的分析存在局限。在未來的後續工作中，引入更精確有效的速度場測量手段可以彌補這個不足。Li, Keyan.M.Phil. Chinese University of Hong Kong 2021.Includes bibliographical references (leaves ).Abstracts also in Chinese.Title from PDF title page (viewed on …)
Currents of power: State broadcasting in South Africa.
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