SAIEE Africa Research Journal最新文献_第4页

Notes for authors 作者须知

IF 1.4

SAIEE Africa Research Journal Pub Date : 2023-11-15 DOI: 10.23919/SAIEE.2023.10319382

引用次数: 0

IF 1.4

SAIEE Africa Research Journal Pub Date : 2023-11-15 DOI: 10.23919/SAIEE.2023.10319376

引用次数: 0

An image encryption based on confusion-diffusion using two chaotic maps and Frobenius endomorphism 基于两个混沌映射和Frobenius自同态的混沌扩散图像加密

IF 1.4

SAIEE Africa Research Journal Pub Date : 2023-11-15 DOI: 10.23919/SAIEE.2023.10319378

Asmaa Hilmi;Soufiane Mezroui;Ahmed El Oualkadi

引用次数: 0

Radiofrequency electromagnetic radiation exposure assessment, analysis, computation, and minimization technique in 5G networks: A perspective on QoS trade-offs 5G网络中的射频电磁辐射暴露评估、分析、计算和最小化技术:QoS权衡的视角

IF 1.4

SAIEE Africa Research Journal Pub Date : 2023-11-15 DOI: 10.23919/SAIEE.2023.10319380

Adedotun T. Ajibare;Sunday O. Oladejo;Stephen O. Ekwe;Lateef A. Akinyemi;Daniel Ramotsoela

{"title":"Radiofrequency electromagnetic radiation exposure assessment, analysis, computation, and minimization technique in 5G networks: A perspective on QoS trade-offs","authors":"Adedotun T. Ajibare;Sunday O. Oladejo;Stephen O. Ekwe;Lateef A. Akinyemi;Daniel Ramotsoela","doi":"10.23919/SAIEE.2023.10319380","DOIUrl":"https://doi.org/10.23919/SAIEE.2023.10319380","url":null,"abstract":"In this study, the specific absorption rate (SAR) and exposure index (EI) of access points (APs) and user equipment (UEs) in fourth-generation (4G) and fifth-generation (5G) wireless technologies are examined with regard to the effects of exposure to radiofrequency (RF) electromagnetic fields (EMF) radiation and the implications of their reduction. We characterize the EI using a classical mathematical method while considering the power density, the SAR, the electric field strength, and the tissue's density and conductivity. As such, a novel exposure-index open-loop power control algorithm is proposed to evaluate the realistic RF-EMF radiation exposure on human users from both the downlink (DL) and uplink (UL) communication devices. To solve an EI minimization problem using the open-loop power control algorithm, we formulate it in the form of a mixed-integer nonlinear programming (MINLP) problem. As the energy capacity (i.e., power density) in wireless networks determines the radiation exposure (SAR and EI), it minimizes the EI by controlling and managing the transmitted and received powers under the restrictions of Quality of Service (QoS), interference, and power, while ensuring the users' QoS requirements are met. Our proposed scheme is numerically compared to other heuristic algorithms and exposure limits established by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) and other similar organizations. Lastly, we compare the emissions from 4G and 5G networks to the emissions from UL and DL transmissions. Our simulation findings indicate that our proposed technique is a good alternative. Our assessment, in terms of numerical results and evaluation, also verifies that the exposures are bearable, fall within the recommended limits, and are minimized without impairing the users' QoS.","PeriodicalId":42493,"journal":{"name":"SAIEE Africa Research Journal","volume":"114 4","pages":"114-127"},"PeriodicalIF":1.4,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10319380","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138138386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

GaN HEMT power amplifier design for 2.45 GHz wireless applications 用于2.45 GHz无线应用的GaN HEMT功率放大器设计

IF 1.4

SAIEE Africa Research Journal Pub Date : 2023-11-15 DOI: 10.23919/SAIEE.2023.10319379

Paula Akossiwa Atchike;Jamal Zbitou;Ahmed El Oualkadi;Pascal Dherbécourt

{"title":"GaN HEMT power amplifier design for 2.45 GHz wireless applications","authors":"Paula Akossiwa Atchike;Jamal Zbitou;Ahmed El Oualkadi;Pascal Dherbécourt","doi":"10.23919/SAIEE.2023.10319379","DOIUrl":"https://doi.org/10.23919/SAIEE.2023.10319379","url":null,"abstract":"Electronic devices with high performances like Power Amplifiers (PA) are very important for Wireless communications. This paper proposes a design of a class AB power amplifier operating at 2.45 GHz, in the S-band frequency. The Cree's CG2H40045F GaN HEMT (High Electron Mobility Transistor) is used for this design. The Gallium Nitride (GaN) technology has been chosen in light of its advantageous properties such as high breakdown voltage, high band gap, as well as high thermal conditions. The paper investigates the different design trade-offs for finding a good balance between various key parameters of the PA (linearity, efficiency, and gain). A design approach has been proposed and the microstrip lines based on the Smith Chart tool available in ADS software have been used for the matching process. The class AB was selected to reach a good agreement between linearity and efficiency, provided by this class. After various process applications from DC characterization to simulations, the proposed design achieves a power added efficiency more than 50% at power saturation with a gain of 15 dB in schematic simulation. The layout dimensions are 55.5 × 64.45 mm\u0000<sup>2</sup>\u0000 on PCB technology.","PeriodicalId":42493,"journal":{"name":"SAIEE Africa Research Journal","volume":"114 4","pages":"106-113"},"PeriodicalIF":1.4,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10319379","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138138385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Editors and reviewers 编辑和评审

IF 1.4

SAIEE Africa Research Journal Pub Date : 2023-08-09 DOI: 10.23919/SAIEE.2023.10214184

引用次数: 0

A cost-sensitive technique to pre-characterize UHF antennas at tertiary education institutions 一种成本敏感技术，用于高等教育机构对超高频天线进行预表征

IF 1.4

SAIEE Africa Research Journal Pub Date : 2023-08-09 DOI: 10.23919/SAIEE.2023.10214186

Casey J. Bryant;P. Gideon Wiid

引用次数: 0

Development of a self-contained robotic hand with dexterous grasping capabilities for research applications 开发一种具有灵巧抓握能力的自主机械手，用于研究应用

IF 1.4

SAIEE Africa Research Journal Pub Date : 2023-08-09 DOI: 10.23919/SAIEE.2023.10214228

Samantha Woods;Callen Fisher

{"title":"Development of a self-contained robotic hand with dexterous grasping capabilities for research applications","authors":"Samantha Woods;Callen Fisher","doi":"10.23919/SAIEE.2023.10214228","DOIUrl":"10.23919/SAIEE.2023.10214228","url":null,"abstract":"Thumb loss can diminish one's hand's functionality by up to 40% and the loss of one's entire hand can severely impact a person's ability to perform simple day-to-day tasks. Therefore, there exists a need to focus on the development of a thumb mechanism which supports dexterous grasping activities in anthropomorphic robotic hands. This paper documents the design process of a novel robotic hand, and shows experimental results validating its overall performance. A large focus was placed on developing a novel thumb mechanism which could replicate the thumb's characteristic movement types, namely flexion-extension, abduction-adduction, and oppositionreposition. Additional focus was placed on developing a mechanism for flexion-extension movement of the fingers which did not incorporate passive components and on producing a fully self-contained prototype — with the electronics and actuators contained inside the palm, and the power supply inset against the back of the palm. The hand successfully followed motion commands from a sensor glove, and was able to replicate 14 grasp configurations which demonstrated its dexterous grasping abilities.","PeriodicalId":42493,"journal":{"name":"SAIEE Africa Research Journal","volume":"114 3","pages":"87-92"},"PeriodicalIF":1.4,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/iel7/8475037/10214182/10214228.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42831271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Initial investigation into bipedal turning: A trajectory optimization study 两足动物转弯轨迹优化的初步研究

IF 1.4

SAIEE Africa Research Journal Pub Date : 2023-08-09 DOI: 10.23919/SAIEE.2023.10214227

Callen Fisher;Dean Pretorius;Nathan Weiss

{"title":"Initial investigation into bipedal turning: A trajectory optimization study","authors":"Callen Fisher;Dean Pretorius;Nathan Weiss","doi":"10.23919/SAIEE.2023.10214227","DOIUrl":"10.23919/SAIEE.2023.10214227","url":null,"abstract":"Humans and animals leverage agility to negotiate the unpredictable environments we occupy. In order for legged robots to leave sterile lab environments, they need to be agile enough to negotiate our lives. Currently, human agility is far superior to the state-of-the-art robotic platforms. Replicating this on robotic platforms require a profound understanding of how contact events are leveraged to complete agile tasks. In line with this aim, this letter was an initial investigation into bipedal turning, to gain insight into how turning was achieved, and to identify any kinematic trends that emerged from the optimization results. This research was conducted on a simulated 10 DoF non-planar bipedal platform with point feet, and made use of a realistic friction cone, and not a linearized approximation. The mathematical model used was based on the bipedal robot currently under development. Two experiments were conducted: rapid turns with a fixed turn angle at varying speeds, and rapid turns with varying turn angles at a fixed speed. Results indicated that slip occurred 93.32% of the contact duration, and turn overshoot was present in all trajectories analyzed. Additionally, a long-time-horizon trajectory was presented to motivate the feasibility and stability of the turn trajectories studied.","PeriodicalId":42493,"journal":{"name":"SAIEE Africa Research Journal","volume":"114 3","pages":"80-86"},"PeriodicalIF":1.4,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/iel7/8475037/10214182/10214227.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45594063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Notes for authors 作者须知

IF 1.4

SAIEE Africa Research Journal Pub Date : 2023-08-09 DOI: 10.23919/SAIEE.2023.10214229

引用次数: 0