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Toward maximising profits from markets: an analysis of the management structure of markets in Kumasi, Ghana

SN Business and Economics 2023年第3期3卷 1-18页

作者： Opoku, Foster Forkuor, David Abass, Kabila Department of Geography and Rural Development Kwame Nkrumah University of Science and Technology Kumasi Ghana

As in many other countries, markets are found to be cardinal centres of job creation, income generation, and revenue mobilisation in Ghana, especially in the urban milieu. They are vital places for expanding community access to basic amenities, social services, and infrastructure development. However, the full prospects of markets, including satellite markets (SMs), may not be realised if they are not effectively managed by local governments. Drawing on the experiences of five SMs in Kumasi, Ghana, this qualitative study through interviews examines the management structure of markets teasing out its challenges. The study found that the management structure of markets involves mainly three-tier levels. Occupying the apex are the local assemblies (local governments) who have the constitutional power to allocate trading space, collect revenues, manage wastes, ensure security and safety, and repair and maintain the market, among others. The local assemblies are conventionally supported by market queens (Dwahemaa) and commodity-specialised leaders (Adwadifuokuohemaa). A major challenge identified was that weak collaboration existed among these actors of market management. For effective management of trading activities in the city geared towards the maximisation of market benefits, the study recommends the creation of a well-resourced and coordinated market management structure involving all relevant actors and stakeholders. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2023.

关键词： Kumasi markets Market benefits Market leaders Market management Urban markets

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Poloidal magnetic field reconstruction by laser-driven ion-beam trace probe in spherical tokamak

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Plasma science and technology 2024年第11期26卷 58-64页

作者： Zuyu ZHANG Tianchao XU Chijie XIAO Xianli HUANG Renchuan HE Ruixin YUAN Xiaoyi YANG State Key Laboratory of Nuclear Physics and Technology School of PhysicsPeking UniversityBeijing 100871People’s Republic of China ENN Science and Technology Development Co.Ltd. Langfang 065001People’s Republic of China Harbin Institute of Technology Harbin 150001People’s Republic of China

The poloidal magnetic field( B_(p)) plays a critical role in plasma equilibrium, confinement and transport of magnetic confinement devices. Multiple diagnostic methods are needed to complement each other to obtain a more accurate B_(p) profile. Recently, the laser-driven ion-beam trace probe(LITP) has been proposed as a promising tool for diagnosing B_(p) and radial electric field( E_(r)) profiles in tokamaks [Yang X Y et al 2014 Rev. Sci. Instrum. 85 11E429]. The spherical tokamak(ST) is a promising compact device with high plasma beta and naturally large elongation. However, when applying LITP to diagnosing B_(p) in STs, the larger B_(p) invalidates the linear reconstruction relationship for conventional tokamaks, necessitating the development of a nonlinear reconstruction principle tailored to STs. This novel approach employs an iterative reconstruction method based on Newton's method to solve the nonlinear equation. Subsequently,a simulation model to reconstruct the B_(p) profile of STs is developed and the experimental setup of LITP is designed for EXL-50, a middle-sized ST. Simulation results of the reconstruction show that the relative errors of B_(p) reconstruction are mostly below 5%. Moreover, even with 5 mm measurement error on beam traces or 1 cm flux surface shape error, the average relative error of reconstruction remains below 15%, initially demonstrating the robustness of LITP in diagnosing B_(p) profiles in STs.

关键词： laser-driven ion-beam trace probe poloidal magnetic field diagnostic iterative reconstruction

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The Power of Materials: The Impact of Tactile Experience with Biophilic Materials on Women's Anxiety

The Power of Materials: The Impact of Tactile Experience wit...

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2023 International Symposium on World Ecological Design, ISWED 2023

作者： Xu, Jing Huang, Guanghui The Digital Arts and Cultural Industry Development Research Group Macau University of Science and Technology China Faculty of Humanities and Arts Macau University of Science and Technology China

ISBN: (纸本)9781643685069

Alleviating the prevalence of anxiety disorders in women is beneficial for sustainable reproductive health. This study discusses the potential role of tactile stimulation on emotion regulation based on touch therapy. It explores the effects of directionality and roughness of biophilic materials on adjusting anxiety by guiding women to interact with different Biophilic materials. The study covered 30 female subjects sequentially exposed to four raw materials. Heart and respiratory rate data were collected, combined with a visual analogue scale to assess tactile pleasantness. Materials characterized with high natural directionality and low roughness evoked pleasant emotions, and materials with low roughness were associated with modulation of anxiety states. Various tactile stimuli trigger associative memories and stimulate the sympathetic nervous system to modulate anxiety. This contributes to a deeper understanding of the link between anxiety mood changes and material properties, reveals potential factors affecting anxiety relief, and facilitates the management of anxiety symptoms in women in the future. © 2024 The Authors.

关键词： Associative processing

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Determining the parameters and chemical behaviour of the overdriven detonation reaction zone of CL-20-based aluminized explosives

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Defence technology(防务技术) 2025年第5期47卷 46-66页

作者： Moyan Liu Yan Liu Fan Bai Hongfu Wang Shanyong Chu Fenglei Huang State Key Laboratory of Explosion Science and Safety Protection Beijing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China China Research and Development Academy of Machinery Equipment Beijing 100089China

The new CL-20(hexanitrohexaazaisowurtzitane)type aluminized explosives in the overdrive detonation(ODD)conditions of the core problem is how to accurately represent the state of the overdrive detonation *** this end,this paper is based on the impedance matching method to test the ODD conditions of CL-20 type aluminium explosive particle *** the interfacial pressure of the shock wave in different *** the characteristic parameters of the reaction zone of the detonation of CL-20 aluminized *** the parameters of the JoneseWilkinseLee(JWL)+γ equation for the detonation products(DPs).Revealed the effect of different DPs equation of state(EOS)on the Hugoniot pressure of *** results indicate that when the content of aluminum powder ranges from 0%to 30%,the duration of the ODD reaction zone and the width of the detonation reaction zone of the CL-20-based aluminized explosive are directly proportional to the content of aluminum *** width of the detonation reaction zone is increased by 1.97 times to 2.7 times compared to that of the reaction zone without the addition of aluminum ***,the energy release efficiency of the detonation reaction zone is inversely proportional to the content of aluminum *** the aluminum powder content was held constant,the incorporation of AP caused a 25%reduction in the energy release efficiency of the detonation reaction *** with existing ODD state equations,the JWL +γ equation is superior in calibrating overpressure Hugoniot data and the isentropic expansion in the C-J *** deviation between calculated pressure results and experimental measurements is within 6%.

关键词： Equation of state for ODD CL-20-based aluminized explosives Detonation reaction zone Impedance matching Interfacial particle velocity

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Acknowledging Contradictions–Endorsing Change: Transforming the Urban Through Gardening

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Capitalism, Nature, Socialism 2023年第1期34卷 69-87页

作者： Bergame, Nathalie Department of Sustainable Development Environmental Science and Engineering Royal Institute of Technology Stockholm Sweden

The contradictions of commoning practices have recently gained increasing attention in critical research. As such, research has shown that collective practices of gardening in common produce contradictory effects not necessarily in line with progressive ideas of the common. Instead of a general dismissal of commoning due to its documented contradictions, I suggest looking beyond the naïve wishing away of contradictions by way of deploying Marxist dialectics as a research perspective from which to explicate and understand underlying processes. Rather than undermining the common's potential as a post-capitalist alternative, this article uses contradictions as an analytical lens through which the meaning of six contradictions of urban garden commons identified in the academic literature is explored. This article concludes that a conceptual focus on contradictions allows for a reflexive and critical research practice revealing the complexity of dialectical relations through which the practice of gardening propels changes but also the reproduction of existing relations. © 2022 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.

关键词： Dialectics environmental justice nature-based commons relations urban gardening

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IoT cryptography with privacy-preserving ElGamal public key cryptosystem using oppositional artificial flora optimization algorithm

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Multimedia Tools and Applications 2025年第11期84卷 9287-9308页

作者： Paramasivam, Devi Sivaji, Sathyalakshmi Dayanandan, Venkata Subramanian Alqahtani, Abdullah Saleh Department of Computer Science and Engineering Hindustan Institute of Technology and Science Tamil Nadu Chennai India Department of CSE Hindustan Institute of Technology and Science Kelambakam Tamil Nadu Chennai603103 India Department of CSE Velammal Institute of Technology Chennai India Department of Self-Development Skills - Common First Year Deanship King Saud University Riyadh12373 Saudi Arabia

Privacy and security have received significant interest among the research communities Due to the increased exploitation of the Internet of Things (IoT). Since IoT devices gather most of the public data like identity, location, contact numbers, and energy utilization, security, and privacy become crucial. The lack of well-defined IoT-enabled security and privacy schemes will prevent the applicability of the IoT technologies from the client side. Therefore, this paper presents an ElGamal public key cryptosystem (EGPKC) for generating optimal keys utilizing an Oppositional Artificial Flora Optimization (EGPKC-OAFA) technique intended for preserving privacy in IoT. Additionally, the EGPKC approach with an optimum generation of authentication keys is applied on the medium access control (MAC) header for secure authentication. Besides, the optimal key selecting process for EGPKC occurs by employing the OAFA approach which inherits the oppositional-based learning (OBL) concept and classical artificial flora approach. To evaluate the effective analysis of the EGPKC-OAFA algorithm, huge simulations such as Known plaintext attack (KPA), chosen-plaintext attack (CPA), key sensitivity, and correlation coefficient are employed and the result is determined by different feature intervals. Accordingly, KPA and CPA reached the minimum value of 0.0987 and -0.0499 respectively. As a result, the proposed EGPKC-OAFA algorithm obtained superior performance compared to other methods. © The Author(s), under exclusive licence to Springer science+Business Media, LLC, part of Springer Nature 2024.

关键词： Internet of things

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Flamelet-like models applied in scramjet combustors:A state of art and prospect

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Chinese Journal of Aeronautics 2023年第10期36卷 24-43页

作者： Tao TANG Zhenguo WANG Yuhui HUANG Mingbo SUN Hongbo WANG Guoyan ZHAO Jiangfei YU College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China Equipment Project Management Center Equipment Development DepartmentBeijing 100089China

Developing supersonic combustion models with efficiency,accuracy and practicality is important foundation to deeply understand the complex combustion processes in scramjet *** by efficiency and intuition,the flamelet-like models are widely used models in computational combustion ***,the supersonic combustion flow field has the nature of strong compressibility,multiple modality,and multiple scales,which poses a great challenge to the traditional flamelet-like models with fixed boundary conditions,and then the complex chemical reaction mechanisms that may face will impose additional computational *** this context,this paper reviews the flamelet-like models used in scramjet engines,and summarizes prominent issues in the application practice,including modeling partially premixed combustion,defining progress variable,solving temperature efficiently,evaluating assumed Probability Density Function(PDF)models,and treating mixture fraction ***,possible prospects and directions of improvements are proposed and highlighted for the flamelet-like *** fully describe the physicochemical scenario and address the raised challenges,these improvements are dedicated to dealing with the compressibility,temperature rise,time-scales,species of interest,multi-inlet combustion,the progress variable definition,and the higher Mach number flight condition.

关键词： Combustion model Flamelet-like model Model improvements Supersonic combustion Scramjet

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Understanding the hydrocarbon-generation potential on jurassic coal-measure source rocks in the Junggar Basin: From the perspective of hydrogen-rich molecular structure

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Petroleum science 2024年第5期21卷 2969-2983页

作者： Tian-Chen Ge Xiang-Chun Chang Guan-Long Zhang Jun-Jian Zhang Rui-Chao Guo Wei-Zheng Gao Ling-Yu Zhao Shang-Bin Wang Jia-Qi Duan College of Earth Science and Engineering Shandong University of Science and TechnologyQingdao266590ShandongChina Laboratory for Marine Mineral Resources Qingdao Marine Science and Technology CenterQingdao266237ShandongChina Research Institute of Petroleum Exploration and Development Shengli Oil CompanySinopecDongying257001ShandongChina School of Geology and Mining Engineering Xinjiang UniversityUrumqi830017XinjiangChina

The Jurassic coal-measure source rocks in the Junggar Basin have drawn considerable attention in recent years. In our hydrocarbon thermal simulation experiments of these rocks, we found that the dark mudstone evaluated as good source rock, had a much lower hydrocarbon generation capacity than the coal and carbonaceous mudstone, evaluated as poor source rock. Based on this background, we performed Fourier transform infrared spectroscopy(FTIR) and combined the results of semi-open thermal simulation experiments to explore the association between the molecular structure and hydrocarbon production capacity, with the aim of obtaining a new understanding of hydrocarbon potential of Jurassic coal-measure source rocks from the perspective of molecular structure. The results indicate that coals exhibit lower condensation of aromatic structures and higher relative abundance of aliphatic structures with a higher degree of branched chaining than mudstones and carbonaceous mudstones. Apparent aromaticity(f_a), aromatic abundance parameter I, and degree of condensation(DOC) are negatively correlated with organic matter abundance. The aliphatic structural parameter H demonstrates a substantial positive correlation with organic matter abundance. Furthermore, aliphatic relative abundance factor A is associated with the type of organic matter;the better is the type of the organic matter, the larger is the A value. The combination of the molecular structures with the thermal simulation results shows that the aliphatic hydrogen enrichment of selected carbonaceous mudstone is similar to that of coal. However, the relative abundance of the aliphatic group of it is high, and the DOC of the aromatic structure is low, making the hydrocarbon generation base stronger and easier to crack. Thus, the hydrocarbon generation capacity of carbonaceous mudstone is slightly higher than that of coal. Mudstone has low H and I values, and the DOC is high, indicating that its hydrocarbon base is low, so i

关键词： Coal-measure source rock Hydrocarbon potential Macromolecular structure Semi-open system pyrolysis Junggar basin

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Swarm Mode Design and Hybrid Flocking Control Algorithm for Swarm Operation of Small Fixed-wing UAVs

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Journal of Institute of Control, Robotics and Systems 2024年第11期30卷 1277-1286页

作者： Song, Yeongho Park, Hwi Sung You, Youngbin Lee, Min Oh, Hyondong Department of Mechanical Engineering Ulsan National Institute of Science and Technology Korea Republic of Agency for Defense Development Korea Republic of LIGNex1 Korea Republic of

This paper presents a swarm system for small fixed-wing unmanned aerial vehicles (UAVs). To enable multiple UAVs to perform various missions while maintaining close proximity and avoiding collisions, we develop a hybrid-flocking control algorithm that combines three types of control protocols: vector field guidance for path following and loitering, the augmented Cucker Smale model for collective flocking behavior, and a potential field for collision avoidance. Additionally, to address the requirements of different mission scenarios, we define several swarm modes: swarm collective loitering for cohesive circling at the same altitude, swarm group loitering for circling at different altitudes, swarm movement for flocking flight toward a target point, and individual loitering for single UAV circling. To reduce the risk of collisions during mode transitions, we employ k-means clustering to form subgroups and optimize control weights within the hybrid-flocking control algorithm. The effectiveness of the proposed system is validated through simulations of swarm mission scenarios. These simulations demonstrate that missions can be performed safely without collisions by utilizing optimized weights for the various swarm modes. © ICROS 2024.

关键词： Unmanned aerial vehicles (UAV)

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Optimizing pump beam waist in general condition of spontaneous parametric down-conversion

Optimizing pump beam waist in general condition of spontaneo...

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2024 Conference on Lasers and Electro-Optics/Pacific Rim, CLEO-PR 2024

作者： Lee, Jungmo Park, Kyungdeuk Im, Dong-Gil Kim, Dongkyu Jo, Yonggi Park, Nam Hun Ihn, Yong Sup Advanced Defense Science & Technology Research Institute Agency for Defense Development Daejeon Korea Republic of

We have determined the optimal pump beam waist to maximize the efficiency of photon pair generation via spontaneous parametric down-conversion (SPDC) under general conditions, including broad spectral characteristics,...

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