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Smart Grid and Renewable Energy 2022年第1期13卷 1-16页

作者： Derek Ajesam Asoh edwin Nyuysever Mbinkar Albert Nouck Moutlen Laboratoire de Génie Electrique Mécatronique et Traitement du Signal ENSPY University of Yaounde I Yaounde Cameroon NAHPI/HTTTC University of Bamenda Bamenda Cameroon ENEO Douala Cameroon

This study presents an intelligent approach for load frequency control (LFC) of small hydropower plants (SHPs). The approach which is based on fuzzy logic (FL), takes into account the non-linearity of SHPs—something which is not possible using traditional controllers. Most intelligent methods use two- input fuzzy controllers, but because such controllers are expensive, there is economic interest in the relatively cheaper single-input controllers. A non- linear control model based on one-input fuzzy logic PI (FLPI) controller was developed and applied to control the non-linear SHP. Using MATLAB/Si- mulink SimScape, the SHP was simulated with linear and non-linear plant models. The performance of the FLPI controller was investigated and compared with that of the conventional PI/PID controller. Results show that the settling time for the FLPI controller is about 8 times shorter;while the overshoot is about 15 times smaller compared to the conventional PI/PID controller. Therefore, the FLPI controller performs better than the conventional PI/PID controller not only in meeting the LFC control objective but also in ensuring increased dynamic stability of SHPs.

关键词： Small Hydropower Plant Linear and Non-Linear Model Load Frequency Control Non-Linear Control Fuzzy Logic Controller Renewable Energy

Bayesian data analysis to quantify the uncertainty of intact rock strength

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第1期10卷 11-31页

作者： Luis Fernando Contreras edwin T.Brown Marc Ruest The University of Queensland St Lucia CampusBrisbaneQLD 4072Australia Golder Associates Pty.Ltd. BrisbaneAustralia

One of the main difficulties in the geotechnical design process lies in dealing with uncertainty. Uncertainty is associated with natural variation of properties, and the imprecision and unpredictability caused by insufficient information on parameters or models. Probabilistic methods are normally used to quantify uncertainty. However, the frequentist approach commonly used for this purpose has some ***, it lacks a formal framework for incorporating knowledge not represented by data. Second, it has limitations in providing a proper measure of the confidence of parameters inferred from data. The Bayesian approach offers a better framework for treating uncertainty in geotechnical design. The advantages of the Bayesian approach for uncertainty quantification are highlighted in this paper with the Bayesian regression analysis of laboratory test data to infer the intact rock strength parameters σand mused in the Hoek-Brown strength criterion. Two case examples are used to illustrate different aspects of the Bayesian methodology and to contrast the approach with a frequentist approach represented by the nonlinear least squares(NLLS) method. The paper discusses the use of a Student’s t-distribution versus a normal distribution to handle outliers, the consideration of absolute versus relative residuals, and the comparison of quality of fitting results based on standard errors and Bayes factors. Uncertainty quantification with confidence and prediction intervals of the frequentist approach is compared with that based on scatter plots and bands of fitted envelopes of the Bayesian approach. Finally, the Bayesian method is extended to consider two improvements of the fitting analysis. The first is the case in which the Hoek-Brown parameter, a, is treated as a variable to improve the fitting in the triaxial region. The second is the incorporation of the uncertainty in the estimation of the direct tensile strength from Brazilian test results within the overall evaluati

关键词： Uncertainty Intact rock strength Bayesian analysis Hoek-Brown criterion

Microcontroller Control of Reactive Power Compensation for Growing Industrial Loads

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Energy and Power Engineering 2022年第9期14卷 460-476页

作者： edwin N. Mbinkar Derek Ajesam Asoh Sulayman Kujabi Laboratoire de Génie Electrique Mécatronique et Traitement du Signal ENSPY Université de Yaoundé I Yaounde Cameroun Department of Electrical and Electronic Engineering National Higher Polytechnic Institute (NAHPI) University of Bamenda Bamenda Cameroon Department of Electrical and Power Engineering Higher Technical Teacher Training College (HTTTC) University of Bamenda Bamenda Cameroon Gambian Technical Training Institute Banjul The Gambia

Many industrial installations in developing countries start-up as small factories, without regard for the need of compensation of reactive power, leading to significant financial losses in the long term. By improving the power factor, the customer can reduce its power demand and potentially increase efficiency of their equipment. A PIC microcontroller is used to switch capacitor banks to compensate for the reactive power. In order to determine the size of the capacitor bank needed, the microcontroller calculates the phase difference between the voltage and the current. The results obtained based on the lagging power factor for three test loads show an improvement in the power factor from 0.52 to 0.96 under different test load conditions.

关键词： Power Factor Compensation Capacitor Bank PIC Microcontroller Reactive Power

Maximum Power Point Tracking Using the Incremental Conductance Algorithm for PV Systems Operating in Rapidly Changing Environmental Conditions

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Smart Grid and Renewable Energy 2022年第5期13卷 89-108页

作者： Derek Ajesam Asoh Brice Damien Noumsi edwin Nyuysever Mbinkar Laboratoire de Génie Electrique Mécatronique et Traitement du Signal ENSPY University of Yaounde I Yaounde Cameroon Department of Electrical/Electronic Engineering NAHPI University of Bamenda Bamenda Cameroon Higher Technical Teacher Training College (HTTTC) University of Bamenda Bamenda Cameroon Department of Electrical/Electronics Engineering Nigeria Army College of Environmental Studies and Technology (NACEST) Makurdi Nigeria

Maximum Power Point Tracking (MPPT) is an important process in Photovoltaic (PV) systems because of the need to extract maximum power from PV panels used in these systems. Without the ability to track and have PV panels operate at its maximum power point (MPP) entails power losses;resulting in high cost since more panels will be required to provide specified energy needs. To achieve high efficiency and low cost, MPPT has therefore become an imperative in PV systems. In this study, an MPP tracker is modeled using the IC algorithm and its behavior under rapidly changing environmental conditions of temperature and irradiation levels is investigated. This algorithm, based on knowledge of the variation of the conductance of PV cells and the operating point with respect to the voltage and current of the panel calculates the slope of the power characteristics to determine the MPP as the peak of the curve. A simple circuit model of the DC-DC boost converter connected to a PV panel is used in the simulation;and the output of the boost converter is fed through a 3-phase inverter to an electricity grid. The model was simulated and tested using MATLAB/Simulink. Simulation results show the effectiveness of the IC algorithm for tracking the MPP in PV systems operating under rapidly changing temperatures and irradiations with a settling time of 2 seconds.

关键词： Modeling Simulation PV System Maximum Power Point Tracking (MPPT) Incremental Conductance Algorithm MATLAB/Simulink

Antibiotic prophylaxis in cirrhosis patients with upper gastrointestinal bleeding:An updated systematic review and meta‐analysis

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Portal Hypertension & Cirrhosis 2022年第3期1卷 167-177页

作者： Yu Jun Wong Chin Kimg Tan Yuen Lin Yii Yoko Wong Yew Chong Tam edwin Chan Juan G.Abraldes Department of Gastroenterology&Hepatology Changi General HospitalSingaporeSingapore Duke‐NUS Medical School SingaporeSingapore Singapore Health Service SingaporeSingapore Cochrane Singapore SingaporeSingapore Singapore Clinical Research Institute SingaporeSingapore Education Resource Centre Medical BoardSingapore General HospitalSingaporeSingapore Division of Gastroenterology University ofAlbertaEdmontonCanada

Objective:Emerging evidence suggest that antibiotic prophylaxis may be omitted in early cirrhosis patients with upper gastrointestinal bleeding(UGIB),which question the benefits of antibiotic prophylaxis on rebleeding,mortality related to ongoing bleeding,and the need for salvage *** the management of UGIB has improved over time since the last review a decade ago,we performed an updated meta‐analysis to review the benefits of antibiotic prophylaxis in cirrhosis patients with ***:Six electronic databases including PubMed/MEDLINE,EMBASE,Scopus,Web of Science,Cochrane library,and *** were systematically searched up to December 1,*** primary outcome was 6 weeks *** outcomes include the risk of infection,rebleeding at 7 days and 6 weeks,mortality related to ongoing bleeding,need for salvage therapy,and infection‐related ***:Eighteen studies(12 randomized controlled trials[RCT],6 non‐RCT)from 3180 subjects were identified among 2129 *** prophylaxis reduces mortality at 6 weeks,risk of infection,and infectionrelated mortality(pooled relative risk:0.72,0.39,and 0.41,respectively).Although antibiotics reduce the risk of rebleeding and the amount of blood transfusion,they did not reduce the risk of mortality from ongoing bleeding nor the need for salvage *** prophylaxis may shorten the length of stay in the intensive care ***:Antibiotic prophylaxis reduces rebleeding,6‐week mortality,and infection‐related *** to the low risk of infection and death,dedicated studies are warranted to evaluate the benefit of antibiotic prophylaxis in early cirrhosis with UGIB.

关键词： endoscopy esophageal and gastric varices hemorrhage hypertension,portal infection rebleeding transjugular intrahepatic portosystemic shunt

Natural sources, biosynthesis, biological functions, and molecular mechanisms of shikimic acid and its derivatives

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Asian Pacific Journal of Tropical Biomedicine 2023年第4期13卷 139-147页

作者： Gopalsamy Rajiv Gandhi Alan Bruno Silva Vasconcelos Poovathumkal James Antony Monalisa Martins Montalvão Mariana Nobre Farias de Franca Varghese edwin Hillary Stanislaus Antony Ceasar Dan Liu Division of Phytochemistry and Drug Design Department of BiosciencesRajagiri College of Social SciencesKalamaserryKochi 683104India Laboratory of Biology and Immunology of Cancer and Leishmania Department of MorphologyFederal University of SergipeSão Cristóvão 49100.000SergipeBrazil Nepal Jesuit Society Human Resource Development and Research CentreKathmandu 44600Nepal Postgraduate Program of Health Sciences Federal University of SergipeCampus Prof.João Cardoso NascimentoAracaju 49060.108SergipeBrazil Division of Plant Molecular Biology and Biotechnology Department of BiosciencesRajagiri College of Social SciencesKalamaserryKochi 683104India School of Food and Biological Engineering Chengdu UniversityChengdu 610106China

Shikimic acid is a hydroaromatic compound possessing critical biological properties,such as antibacterial and antiviral *** review mainly focused on shikimic acid and its *** first briefly introduced the sources of shikimic acid and its derivatives and discussed their *** in vitro and in vivo studies indicate that shikimic acid and its derivatives exhibit diverse bioactivities,such as antioxidant,antiviral,anti-inflammatory,antibacterial,hypolipidemic,bone protective,skin protective,neuroprotective,and antidiabetic *** mainly focused on the related molecular ***,the wide range of bioactivities of shikimic acid and its derivatives indicate that a more detailed exploration of their potential for the prevention and treatment of certain diseases is warranted.

关键词： Natural products Shikimate Ginkgo biloba Neuroprotection Inflammation

The Signatures of Acid Concentration on the Optical Band Gap and Associated Band Tails of Chitosan from Shrimp for Application in Optoelectronic Devices

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Advances in Chemical Engineering and Science 2022年第1期12卷 1-12页

作者： edwin Atego John O. Agumba Godfrey O. Barasa Department of Physical Sciences Jaramogi Oginga Odinga University of Science and Technology (JOOUST) Bondo Kenya

Over the recent years, the global increase of electronic wastes from electrical and electronic devices (e-wastes) has been on an alarming trend in quantity and toxicity and e-wastes are non-biodegradable resulting in its cumulative increase over time. Changes in technology and unrestricted regional movement of electrical devices have facilitated the generation of more e-wastes leading to high levels of air, soil and water pollution. To address these challenges, biodegradable organic components such as chitosan have been used to replace their inorganic counterparts for optoelectronic device applications. However, in-depth knowledge on how such materials can be used to tune the optical properties of their hybrid semiconductors is unrivaled. Thus, systematic studies of the interplay between the preparation methods and optical band gap and Urbach energy of such organic components are vital. This study has thus been dedicated to map out the effect of acid concentrations during chitosan extraction on the corresponding optical band gap and Urbach energy with a view to improving its applications in optoelectronic devices. The, 1.0 to 2.5 molar hydrochloric acid (HCl) was used for 12 hours at room temperature during demineralization and 2.0 molar sodium hydroxide (NaOH) during deprotonation processes. The absorbance spectrum of the samples was collected by UV-Vis spectrophotometer and band gap energies were analyzed by performing Tauc’s plot. This study revealed that the energy band gap of chitosan extracted from 1 M HCl, 1.5 M HCl, 2.0 M HCl and 2.5 M HCl were 3.72 eV, 3.50 eV, 3.45 eV and 3.36 eV respectively. Furthermore,

关键词： Chitosa Optical Band Gap Urbach Energy Absorbance Spectrum Tauc Plot

Network Analysis Reveals A Signaling RegulatoryLoop in PIK3CA-mutated Breast Cancer Predicting Survival Outcome

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Genomics, Proteomics & Bioinformatics 2017年第2期15卷 121-129页

作者： Shauna R. McGee Chabane Tibiche Mark Trifiro edwin Wang National Research Council Canada Montreal QC H4P 2R2 Canada Department of Experimental Medicine McGill University Montreal QC H3A 2B2 Canada Center for Bioinformatics McGill University Montreal QC H3G OB1 Canada Lady Davis Institute for Medical Research of the Jewish General Hospital Montreal QC H3T 1E2 Canada Center for Health Genomics and Informatics Calgary AB T2N 4N1 Canada Department of Biochemistry & Molecular Biology/Medical Genetics/Oncology University of Calgary Cumming School of Medicine Calgary AB T2N 4N1 Canada Alberta Children's Hospital Research Institute Calgary AB T2N 4N1 Canada Arnie Charbonneau Cancer Research Institute Calgary AB T2N 4N1 Canada O'Brien Institute for Public Health Calgary AB T2N 4N1 Canada

Mutated genes are rarely common even in the same pathological type between cancer patients and as such, it has been very challenging to interpret genome sequencing data and difficult to predict clinical outcomes. PIK3 CA is one of a few genes whose mutations are relatively popular in tumors. For example, more than 46.6% of luminal-A breast cancer samples have PIK3 CA mutated, whereas only 35.5% of all breast cancer samples contain PIK3 CA mutations. To understand the function of PIK3 CA mutations in luminal A breast cancer, we applied our recentlyproposed Cancer Hallmark Network Framework to investigate the network motifs in the PIK3CA-mutated luminal A tumors. We found that more than 70% of the PIK3CA-mutated luminal A tumors contain a positive regulatory loop where a master regulator(PDGF-D), a second regulator(FLT1) and an output node(SHC1) work together. Importantly, we found the luminal A breast cancer patients harboring the PIK3 CA mutation and this positive regulatory loop in their tumors have significantly longer survival than those harboring PIK3 CA mutation only in their tumors. These findings suggest that the underlying molecular mechanism of PIK3 CA mutations in luminal A patients can participate in a positive regulatory loop, and furthermore the positive regulatory loop(PDGF-D/FLT1/SHC1) has a predictive power for the survival of the PIK3 CAmutated luminal A patients.

关键词： Network analysis PIK3CA mutation Network motif Breast cancer Genome sequencing Survival

通过可控的裂变-聚合策略合成紫外光到蓝光发射的硫纳米点

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Science China Materials 2022年第10期65卷 2786-2792页

作者：肖炼杜全超黄毅程士嘉尹帅 Teck Neng Wong edwin Kok Lee Yeow 孙汉东 Division of Physics and Applied Physics School of Physical and Mathematical SciencesNanyang Technological UniversitySingapore 637371Singapore Division of Chemistry and Biological Chemistry School of Physical and Mathematical SciencesNanyang Technological UniversitySingapore 637371Singapore Research Institute of Aero-Engine Beihang UniversityBeijing 100083China School of Mechanical and Aerospace Engineering Nanyang Technological UniversitySingapore 639798Singapore MajuLab International Joint Research Unit UMI 3654CNRSUniversitéCôte d’AzurSorbonne UniversitéNational University of SingaporeNanyang Technological UniversitySingapore 637371Singapore

本文通过可控的裂变-聚合策略合成紫外光到蓝光发射的硫纳米点,实现了在短波长范围内的荧光发射,其最高的荧光量子产率可达59.4%.由于其独特的裂变-聚合生成机理,这种合成方法能控制硫纳米点的尺寸(3.2–5.6 nm),因此可实现从紫外到深蓝... 详细信息

本文通过可控的裂变-聚合策略合成紫外光到蓝光发射的硫纳米点,实现了在短波长范围内的荧光发射,其最高的荧光量子产率可达59.4%.由于其独特的裂变-聚合生成机理,这种合成方法能控制硫纳米点的尺寸(3.2–5.6 nm),因此可实现从紫外到深蓝色(342–430 nm)可调谐发光,并抑制非辐射复合中心的生成以及深能级发射.通过光谱表征和理论计算探究了硫纳米点的发光机理和量子限域效应.研究结果表明了硫纳米点在紫外光电子学、生物医学治疗和杀菌等应用领域的可能性.

关键词：纳米点量子限域效应生物医学非辐射复合荧光量子产率蓝光发射紫外光光谱表征

Rare Earth Doped Glass Waveguide Amplifiers

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光学学报 2003年第S1期23卷 357-358页

作者： edwin Y.B. Pun Department of Electronic Engineering City University of Hong Kong Tat Chee Avenue Kowloon Hong Kong P.R.China

Progress in rare earth doped planar glass waveguide devices has been significant over the past few years. The history and applications of these devices are reviewed.

关键词： been Rare Earth Doped Glass Waveguide Amplifiers have for EDWA dBm were