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50th International Universities Power Engineering Conference (UPEC)

作者： Melato, Popi Mbuli, Nhlanhla Pretorius, Jan-Harm Univ Johannesburg Fac Engn & Built Environm Johannesburg South Africa

ISBN: (纸本)9781467396820

Steady state voltage problems in power systems are those associated with undervoltages resulting from increasing loads. Steady overvoltages can also arise when loads served by networks are reduced, and the problem can be exacerbated if lines supplying load centres are long. This paper reports on a study that was conducted to assess the impact of derating voltage of lines, by using step down transformers on the lowest load a network can accommodate without overvoltages. A program written in python and using PSS/E to perform loadflows, was used to perform analyses at various load levels. The study showed that with derating transformers installed, voltages in the system were better, there was less reactive power flow, and active power losses were lower. Derating lines using step down transformers is therefore a potential solution for serving low load levels.

关键词： Active power losses Power System Simulator for Engineering (PSS/E) python programming language steady state overvoltages step down transformers

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Development of the Program for Calculation of Losses of Electric Capacitors in Non-Sinusoidal Modes of Operation

Development of the Program for Calculation of Losses of Elec...

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2024 Conference of Young Researchers in Electrical and Electronic Engineering, ElCon 2024

作者： Ermilov, Vladimir Pechnikov, Alexey Peter the Great St. Petersburg Polytechnic University Higher School of High Voltage Engineer Saint Petersburg Russia

ISBN: (纸本)9798350360646

Due to the need for simplifying design and optimization processes of electrical capacitors with specified parameters, this work was aimed at research of specialized software for calculating losses in capacitors under non-sinusoidal modes of operation. During the creation of the program, the program code was written in the python programming language and created graphical application for the convenience. For approbation of the program frequency spectra of capacitance and loss tangent of metal-film capacitor were measured and used for calculation the power of thermal losses, that was taken for the simulation in Comsol software. Simulation results were compared with experimental ones. The result of work is program for calculating capacitor losses under non-sinusoidal operating conditions. The software will simplify the design process of electrical products and simplify stages of development and calculation losses of capacitors designed to operate in non-sinusoidal modes. © 2024 IEEE.

关键词： capacitor losses Comsol software metallized film capacitors non-sinusoidal modes of operation python programming language

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A GIS approach for improving transportation and mobility inIqaluit, Nunavut Territory

A GIS approach for improving transportation and mobility inI...

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作者： Copithorne, Dana University of Victoria

学位级别：master

Planning for transportation within northern Canadiancommunities presents unique challenges, but new research toolsoffer opportunities for testing potentially innovative solutionsthat might help improve mobility within these communities. Inparticular, problem solving has been enriched in recent years byusing the spatial modeling methods offered by GeographicalInformation Systems (GIS). This thesis first reviews various GISmethods before applying one method – the ‘Route Utility Theory’ –to a newly-developed set of metrics for determining the cost ofalternate modes of intracommunity transportation. This set ofmetrics is applied to a data set that represents the trips orjourneys made by non-car users in Iqaluit, the capital city ofNunavut Territory. GIS data on roads, walking trails, landcontours, and public and residential neighbourhoods are *** results facilitate comparisons between road options and trailoptions for improving the movement of people within Iqaluit. Fivebus routes were then custom designed and compared using the study’smetrics. The study found that increasing bus and trail optionswithin Iqaluit would provide more efficient options for non-carusers. It is argued that the study’s metrics can be adapted forapplication in other northern communities, and possibly in otherisolated and rural communities in different worldsituations.%%%%Graduate

关键词： Geographical Information Systems Geography Geomatics Canada Northern Studies Nunavut Iqaluit Urban Design and Planning Urban Geography transportation engineering Sustainablility python programming language public transit pedestrians bus Open Source Software

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Charged Silicon Nitride Films: Field-Effect Passivation of Silicon Solar Cells and a Novel Characterization Method through Lifetime Measurements

Charged Silicon Nitride Films: Field-Effect Passivation of S...

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作者： Yang, Qun Arizona State University

学位级别：M.S.

Silicon (Si) solar cells are the dominant technology used in the Photovoltaics industry. Field-effect passivation by means of electrostatic charges stored in an overlying insulator on a silicon solar cell has been proven to be a significantly efficient way to reduce effective surface recombination velocity and increase minority carrier lifetime. Silicon nitride (SiNx) films have been extensively used as passivation layers. The capability to store charges makes SiNx a promising material for excellent feild effect passivation. In this work, symmetrical Si/SiO2/SiNx stacks are developed to study the effect of charges in SiNx films. SiO 2 films work as barrier layers. Corona charging technique showed the ability to inject charges into the SiNx films in a short time. Minority carrier lifetimes of the Czochralski (CZ) Si wafers increased significantly after either positive or negative charging. A fast and contactless method to characterize the charged overlying insulators on Si wafer through lifetime measurements is proposed and studied in this work, to overcome the drawbacks of capacitance-voltage (CV) measurements such as time consuming, induction of contanmination and hysteresis effect, etc. Analytical simulations showed behaviors of inverse lifetime (Auger corrected) vs. minority carrier density curves depend on insulator charge densities (N f). From the curve behavior, the Si surface condition and region of Nf can be estimated. When the silicon surface is at high strong inversion or high accumulation, insulator charge density (Nf) or surface recombination velocity parameters (Sn0 and Sp0) can be determined from the slope of inverse lifetime curves, if the other variable is known. If S n0 and Sp0 are unknown, Nf values of different samples can be compared as long as all have similar Sn0 and Sp0 values. Using the saturation current density (J 0) and intercept fit extracted from the lifetime measurement, the bulk lifetime can be calculated. Therefore, this method is fea

关键词： Biochemistry Bioinformatics Molecular biology Chromatic Acclimation Next-generation sequencing Photosynthesis Phycoerythrin Protein crystallography python programming language

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Výuka pokročilých konstrukcí jazyka python na základě poskytování zpětné vazby ke studentským kódům

Výuka pokročilých konstrukcí jazyka Python na základě ...

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作者： John, Petr Brno University of Technology

Tato bakalářská práce se zabývá problematikou vyučování jazyka python pomocí systému, který studentům poskytne zpětnou vazbu k jejich řešení. Cílem pr&... 详细信息

Tato bakalářská práce se zabývá problematikou vyučování jazyka python pomocí systému, který studentům poskytne zpětnou vazbu k jejich řešení. Cílem práce bylo vytvořit systém schopný vyhodnocovat studentská řešení a poskytovat zmíněnou zpětnou vazbu. Důraz práce je kladen na zpětnou vazbu, která je studentům poskytována, a také na možnosti spojené s omezením zdrojů použitých při řešení. Vytvořený systém poskytuje zpětnou vazbu na základě analýzy abstraktních syntaktických stromů sestavených z odevzdaného řešení, umožňuje připojit doporučení z programů třetích stran, a také umožňuje nastavit omezení zdrojů, knihoven a funkcí, které mohou být při řešení použity. Systém byl použit v letním semestru při výuce předmětu ISJ a 60 % studentů vylepšilo svoje řešení na základě doporučení ze systému. Tyto skutečnosti dokazují, že systém je možné využít při výuce jazyka python v praxi.

关键词： jazyk python automatické vyhodnocování automatické výukové systémy zpětná vazba doporučení ke kódu python programming language automated evaluation intelligent tutoring systems feedback code suggestions Text

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A New ODE-Based Julia Implementation of the Anaerobic Digestion Model No. 1 Greatly Outperforms Existing DAE-Based Java and python Implementations

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PROCESSES 2023年第7期11卷

作者： Allen, Courtney Mazanko, Alexandra Abdehagh, Niloofar Eberl, Hermann J. Univ Guelph Dept Math & Stat Guelph ON N1G 2W1 Canada CHFour Biogas Manotick ON K4M 1A4 Canada

The Anaerobic Digestion Model 1 is the quasi-industry standard for modelling anaerobic digestion, and it has seen several new implementations in recent years. It is assumed that these implementations would give the same results;however, a thorough comparison of these implementations has never been reported. This paper considers four different implementations of ADM1: one in Julia, one in Java, and two in python. The Julia code is a de novo implementation of the ODE formulation of ADM1 that is reported here for the first time. The existing Java and python codes implement the more common DAE formulation. Therefore, this paper also examines how DAE implementations compare to ODE implementations in terms of computational speed as well as solutions returned. As expected, the ODE and DAE forms both return comparable solutions. However, contrary to popular belief, the Julia ODE implementation is faster than the DAE implementations, namely by one to three orders of magnitude of compute time, depending on the simulation scenario and the reference implementation used for comparison.

关键词： anaerobic digestion ADM1 Julia programming language Java programming language python programming language numerical methods performance comparison

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Radiation View Factor for Building Applications: Comparison of Computation Environments

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ENERGIES 2019年第20期12卷 3826-3826页

作者： Alam, Marzia Gul, Mehreen Saleem Muneer, Tariq Heriot Watt Univ Sch Energy Geosci Infrastruct & Soc Boundary Rd N Edinburgh EH14 4AS Midlothian Scotland Edinburgh Napier Univ Sch Engn & Built Environm 10 Colinton Rd Edinburgh EH10 5DT Midlothian Scotland

Computation of view factors is required in several building engineering applications where radiative exchange takes place between surfaces such as ground and vertical walls or ground and sloping thermal or photovoltaics collectors. In this paper, view factor computations are performed for bifacial solar photovoltaic (PV) collectors based on the finite element method (FEM) using two programming languages known as Microsoft Excel-Visual Basic for Applications (VBA) and python. The aim is to determine the computer response time as well as the performance of the two languages in terms of accuracy and convergence of the numerical solution. To run the simulations in python, an open source just-in-time (JIT) compiler called Numba was used and the same program was also run as a macro in VBA. It was observed that the simulation response time significantly decreased in python when compared to VBA. This decrease in time was due to the increase in the total number of iterations from 400 million to 250 billion for a given case. Results demonstrated that python was 71-180 times faster than VBA and, therefore, offers a better programming platform for the view factor analysis and modelling of bifacial solar PV where computation time is a significant modelling challenge.

关键词： building energy exchange view factor python programming language bifacial solar photovoltaic (PV)

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Application of machine learning algorithms for nonlinear system forecasting through analytics-A case study with mining influenced water data

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WATER RESOURCES AND INDUSTRY 2023年 29卷

作者： More, Kagiso Samuel Wolkersdorfer, Christian Tshwane Univ Technol SARChI Chair Mine Water Management Dept Environm Water & Earth Sci Private Bag X680 ZA-0001 Pretoria South Africa

Various techniques have been researched and introduced in water treatment plants to optimise treatment and management processes. This paper presents a solution that can help treatment plants to work more effectively and reach their mine water management goals. Using python 3.7.1 programming language within an Anaconda 4.11.0 platform, neural networks and regres-sion tree algorithms were compared to find the best performing model after the data had un-dergone robust data pre-processing and exploratory data analysis statistical techniques. The main aim was to use this best performing model to forecast mining influenced water (MIW) parameters. This approach will help the treatment plant operators in knowing the future MIW chemistry, and they can eventually plan ahead of time what chemicals and methods to use to treat and manage polluted MIW. Westrand mine pool water near Randfontein, South Africa is used as a case study, in which historical data (2016-2021) from shaft N degrees 9 is used to train and test the algorithms. These algorithms included the artificial neural network (ANN), deep neural network (DNN), gradient boosting and random forest regression trees, while the multivariate long short-term memory (LSTM) was used to generate new data for the best performing algorithm. Different data pre-processing approaches were explored, including data interpolation and anomaly detection. These processes were carried out to highlight the most important part of completing a machine learning related project, which is data analytics. Finally, the random forest regression tree algorithm showed the overall best performance and was used to forecast Fe and acidity concentrations of MIW for 60 days. It could be shown that artificial intelligence techniques are capable to optimise and forecast mine water treatment plant parameters, and it is imperative to perform robust statistical analysis on the data before attempting to build forecasting models.

关键词： Mining influenced water python programming language Forecasting models Data analytics South Africa

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kegg_pull: a software package for the RESTful access and pulling from the Kyoto Encyclopedia of Gene and Genomes

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BMC BIOINFORMATICS 2023年第1期24卷 78-78页

作者： Huckvale, Erik Moseley, Hunter N. B. Univ Kentucky Markey Canc Ctr Lexington KY 40536 USA Univ Kentucky Dept Mol & Cellular Biochem Lexington KY 40536 USA Univ Kentucky Inst Biomed Informat Lexington KY 40536 USA

BackgroundThe Kyoto Encyclopedia of Genes and Genomes (KEGG) provides organized genomic, biomolecular, and metabolic information and knowledge that is reasonably current and highly useful for a wide range of analyses and modeling. KEGG follows the principles of data stewardship to be findable, accessible, interoperable, and reusable (FAIR) by providing RESTful access to their database entries via their web-accessible KEGG API. However, the overall FAIRness of KEGG is often limited by the library and software package support available in a given programming language. While R library support for KEGG is fairly strong, python library support has been lacking. Moreover, there is no software that provides extensive command line level support for KEGG access and *** present kegg_pull, a package implemented in the python programming language that provides better KEGG access and utilization functionality than previous libraries and software packages. Not only does kegg_pull include an application programming interface (API) for python programming, it also provides a command line interface (CLI) that enables utilization of KEGG for a wide range of shell scripting and data analysis pipeline use-cases. As kegg_pull's name implies, both the API and CLI provide versatile options for pulling (downloading and saving) an arbitrary (user defined) number of database entries from the KEGG API. Moreover, this functionality is implemented to efficiently utilize multiple central processing unit cores as demonstrated in several performance tests. Many options are provided to optimize fault-tolerant performance across a single or multiple processes, with recommendations provided based on extensive testing and practical network *** new kegg_pull package enables new flexible KEGG retrieval use cases not available in previous software packages. The most notable new feature that kegg_pull provides is its ability to robustly pull an arbitrary number o

关键词： KEGG REST Application programming interface python programming language Command line interface

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Statistical method for identification of weak nodes in power system based on voltage magnitude deviation

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ELECTRIC POWER SYSTEMS RESEARCH 2021年 200卷 107464-107464页

作者： Yusuff, A. A. Mosetlhe, T. C. Ayodele, T. R. Florida Univ South Africa Elect & Min Engn Dept Coll Sci & Technol Cnr Christiaan Wet & Pioneer Rd Florida South Africa Univ Ibadan Power Energy Machine & Dr Res Grp PEMD Dept Elect & Elect Engn Fac Technol Ibadan Nigeria

Identification of weak buses in an electric power system is important for operational and planning purposes. In this paper, a framework that uses the variance of the magnitude of voltage at load buses when reactive power of all loads are varied concurrently is used to identify a set of weak buses. In the framework, reactive power for all load buses are generated concurrently and independently based on the probability distribution function of load demands at each node. Three IEEE test systems are used to test the framework in Pypower in conjunction with python programming language. The result shows that weak buses can be identified with the framework. It was observed that the first three set of most critical nodes in a network can be identified within a variation of 1% of reactive power at load nodes in case of ordinary power flow (pf), while the same set of nodes can be identified with at least 5% of variation of reactive power at nodes based on optimal power flow (opf). One area of application of this work could be in the use of the variance of voltage magnitude measurements to quickly identify a subset of weak nodes in a network.

关键词： Voltage stability index Critical buses Standard Deviation Bus criticality index python programming language PyPower

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