Digital Commons Network^™

Visualization Of Paleocurrents On A Web Application Using Gplates, Anjan Sapkota

MS in Computer Science Theses

Paleocurrents are flow directions derived from features of sedimentary rocks that reveal the direction of the current of wind or water that deposited the sediment. In 2015, Brand et al. created a global database of paleocurrents, which contains over 1,000,000 measurements worldwide: North America, South America, Australia, Great Britain, parts of Western Europe, China, Africa are fairly well represented; Antarctica, Eastern Europe, and Asia are modestly represented and Russia is poorly represented. The contribution of this thesis is a web application that uses the GPlates’ Application Programming Interface (API) to visualize global paleocurrents through time in an interactive way based …

Scrutiny Of Employee Covenants Not To Compete Under The Rule Of Reason: An Empirical Inquiry, Daniel A. Crane

Notre Dame Law Review Reflection

For over 300 years, the common law has scrutinized employee covenants not to compete for their reasonableness. That is about to change. On April 23, 2024, the Federal Trade Commission announced a rule that will prohibit employers from imposing noncompete agreements on workers. The rule declares all covenants not to compete in the employment context to be unfair methods of competition under section 5 of the FTC Act. If the rule takes effect, thirty million contracts will become illegal. The FTC justifies this rule based on the ostensibly pernicious effects of employee covenants not to compete—limiting employee opportunities to pursue …

Cancelling The "Big Deal" At A Public University: A Discussion Of Stem Faculty Perceptions Of Cancellation And An Examination Of Post-Cancellation Usage Data, Amanda Mccormick, Erin Rowley

Law Librarian Journal Articles

This article discusses how faculty, staff, and students at the University at Buffalo (UB), a public Carnegie R1 university, were impacted by the cancellation of the Elsevier ScienceDirect Big Deal package. After the cancellation, UB participated in a multi-site study which included interviewing faculty about the effect of the cancellation on their research and teaching. In general, the faculty were supportive of the cancellation. There was frustration expressed with the current structure of the publishing industry, particularly with the exorbitant pricing of journal subscriptions. Later analysis of usage data at UB post-cancellation was conducted; unsurprisingly, the data showed a decrease …

The Prospector, December 3, 2024, Utep Student Publications

The Prospector

No abstract provided.

Understanding The Role Of The Heat Transfer Coefficient Between Tool/Workpiece Interface During Friction Stir Welding, Matthew Goodson

Theses and Dissertations

The heat transfer coefficient is a key parameter in modeling friction stir welding and has yet to be measured experimentally. The importance of this parameter was shown through validating friction stir models on both sides of the tool/workpiece interface. Both a transient plunge and a steady state model were validated by matching experimental temperatures. The steady state tool temperatures were matched (with in 2.5%), but the steady state workpiece temperatures were off by around 20%. The transient model of the FSW plunge showed the effect of varying the ℎ𝑊/𝑇 on workpiece temperatures and tool temperatures. Two methods were looked at …

Artificial Creativity: How Artificial Intelligence Will Impact Creativity Via Post-Production, Nicole Dwyer

Honors Thesis

My thesis lives in the world of Post-Production, and it contains both a creative and written component. I was the editor for four Undergraduate thesis projects. Seeking to gain experience in editing various genres, I worked in drama, sports, period piece, coming of age, and adventure. My biggest takeaways from these projects are the importance of organization, communication, time management, and editing with a sense of imagination. I became a more confident, resilient, and prepared editor through these experiences.

Along with the hands-on filmmaking element of my thesis, I also conducted research on how artificial intelligence will impact conceptions of …

Relationship Between The Transition To Remote Work And Job Satisfaction, Eric Wong

JWU Dissertations & Theses

The purpose of this qualitative descriptive research study was to explore how employees who had not worked remotely before, and who began remote jobs, describe the benefits and challenges they experienced during their transition to remote work. Using Maslow’s (1943) hierarchy of needs as the theoretical framework, 10 participants were interviewed regarding the benefits and challenges associated with remote work. Results revealed that the benefits of transitioning to remote work largely increased job satisfaction and job performance. These benefits included limited or no commuting to work, enhanced flexibility in work schedules, reduced or less anxiety during work, and increased family …

Aerodynamic Noise Reduction Of Wind Turbine Blades, Steven Davenport

Honors Theses

This project is presented to meet Western Michigan University’s College of Engineering and Applied Sciences Senior Design requirements. With wind turbines becoming increasingly popular as a form of energy generation, the need to reduce the aerodynamic noise is needed. Most commercial wind farms use turbines with a NACA 0012 airfoil. Thus, that is the only profile shape considered in this research. Seven modifications were made to a NACA 0012 airfoil to reduce aerodynamic noise. The airfoils were designed in SolidWorks and 3D printed at the WMU College of Aviation. The airfoils were simulated in Ansys Fluent and experimentally tested in …

Investigating The Efficacy Of Prompt Engineering Techniques For Research Survey Paper Generation Using Large Language Models, Innocent Obed Awidi

Theses and Dissertations

The recent advancements in large language models (LLMs), such as ChatGPT, offer promising potential for automating academic writing tasks. This study investigates the efficacy of prompt engineering techniques in guiding LLMs to generate high-quality research survey papers, specifically exploring their application in the fields of artificial intelligence (AI) in drug development and large language model customization for classification. Using a mixed-methods approach, this research assessed the impact of prompt engineering on the coherence, relevance, and overall quality of generated content through quantitative and qualitative analyses. Techniques including prompt refinement, contextual prompting, and iterative prompting were systematically applied to enhance the …

A Comparative Study On Mppt Algorithms For Photovoltaic Power Generation Systems, Xinchun Cao, Faqiang Wang

Journal of Electric Power Science and Technology

To address the nonlinear output characteristics of photovoltaic (PV) cells and enhance their utilization efficiency, it is crucial to track their maximum power output in real-time. Starting from an analysis of PV cell output characteristics and based on an explanation of the maximum power point tracking (MPPT) control principle, this paper reviews the algorithms for MPPT in photovoltaic power generation systems. It discusses tracking speed, control accuracy, and issues that need to be addressed in future research and applications. Through experimental comparisons, the paper analyzes differences between various algorithms and between different parameters within the same algorithm, as well as …

Review And Outlook On Active Islanding Of Multi‑Source Distribution Networks Under Extreme Conditions, Chun Chen, Jinjin Wan, Yijia Cao, Chongbo Sun

Journal of Electric Power Science and Technology

The fault distribution network with a high proportion of distributed power supply access possesses active recovery and self-governance capabilities, which is conducive to enhancing the power system's adaptability to climate change and disaster risk management, aligning with the development direction of distribution network technology. Currently, research on active islanding self-recovery and stable operation of distribution networks has received widespread attention. This paper begins with an overview of the connotations of active islanding in multi-source distribution networks, as well as the distinctions between multi-source distribution network islands and microgrid islands. It then analyzes and summarizes the key issues that arise in …

Dynamic Reconstruction Of Active Distribution Networks Based On Second‑Order Cone Programming For Optimal Power Flow Calculation, Jinjun Wang, Tongyu Li, Heng Chen, Tao Liu, Honggang Chen

Journal of Electric Power Science and Technology

To effectively address the uncertainty and volatility brought by the large-scale integration of renewable energy into the grid and achieve optimal operation of the distribution network, a dynamic network reconfiguration optimization method considering the time-varying nature of distributed generation (DG) and load demand characteristics is proposed. Firstly, to tackle the non-convexity of the traditional static branch power flow model, slack variables are introduced to transform it into second-order cone constraints, establishing an optimal power flow model based on second-order cone relaxation. Then, considering the constraints of active management elements in the active distribution network environment, a multi-period distribution network reconfiguration …

Overload Prediction Method Of Distribution Transformer Based On Iar‑Ci Model, Shaofeng Zhang, Jialin Wang, Runrun Li, Xiaoyang Duan, Chenhao Sun, Chun Chen

Journal of Electric Power Science and Technology

With the digitization and intellectualization of power systems, the prediction of distribution transformer overload has become one of the key technologies for realizing intelligent condition-based maintenance. In real-world scenarios, the spatiotemporal factors of distribution transformer overload often exhibit a biased distribution, among which some high-risk and rare (HRR) factors, once occurred, can cause irreversible damage to transformers and should not be ignored. Therefore, this paper proposes a prediction method for distribution transformer overload based on the improved association rules-criticality importance (IAR-CI ) model. Firstly, considering both internal and external factors, multiple data sources are collected to establish a database of …

A Practical Method For Calculating Electrical Distance Based On Network Topology, Jinyu Qin, Xiaoming Mao, Zhe Dong, Chuning Fang

Journal of Electric Power Science and Technology

Electrical distance (ED) is the primary basis for dividing voltage control areas in power grids. Both classic methods and their improved versions for calculating electrical distance rely on the power flow Jacobian matrix, which may lead to frequent adjustments in partitioning schemes and increase the difficulty of reactive power and voltage management as the randomness of power sources and loads continues to grow. Therefore, this paper first reviews the classic definition of electrical distance and then demonstrates that the ratio of voltage changes at a pair of nodes in a power system after a small disturbance can be approximately obtained …

Harmonic Responsibility Estimation Method Based On Gaussian Mixture Model, Xinghua Cao, Richang Xian, Haohan Yang, Shulin Song, Xiaodi Chen

Journal of Electric Power Science and Technology

A harmonic responsibility estimation method based on the Gaussian mixture model (GMM) is proposed for partially observable systems. This method estimates the harmonic responsibility of each harmonic load based on the probabilistic distribution characteristics of measured harmonic voltages, circumventing the difficulties in quantifying harmonic responsibility due to the introduction of unmeasurable line parameters. Specifically, the process begins by training a GMM using the measured harmonic voltage samples. Then, the number and range of Gaussian components in the mixture model are determined based on the Bayesian information criterion and the Kullback-Leibler divergence ratio. Additionally, anomaly detection of harmonic voltage samples is …

Grid Dispatching Strategy For Wireless Charging Road Planning Based On Stackelberg Game, Xinkun Dong, Yonghui Liu

Journal of Electric Power Science and Technology

This paper investigates the planning of wireless charging lanes and further explores the impact of electric vehicles (EVs) charging on the power grid while using these lanes. Firstly, a novel road network traffic model is established based on the distribution of roads, charging stations, and traffic conditions. By analyzing the congestion coefficients of various roads, an optimal planning for wireless charging lanes is proposed. Subsequently, a Stackelberg game model is formulated, where the grid operator acts as the leader and EV users, whose charging behavior aligns with an improved demand response function, act as followers. Finally, the particle swarm optimization …

Capacity Configuration Of Multi‑Functional Electric‑Hydrogen Hybrid Energy Storage System In Grid‑Friendly Wind Farm, Xisheng Wang, Hui Liu, Di Liu, Xianmiao Huang, Yiming Zhao, Kairang Wang, Mingchao Xia, Binhui Pei

Journal of Electric Power Science and Technology

Optimizing the allocation of energy storage resources within wind farms can effectively mitigate the negative impacts of wind power induced strong randomness and volatility on the power system, promoting the construction of grid-friendly wind farms. Currently, wind farm energy storage systems face issues such as single application functions, low equipment utilization rates, and poor profitability, which constrain the large-scale application of energy storage systems in wind farms. To address these issues, this paper proposes a method for optimizing the capacity allocation of a multifunctional electrical-hydrogen hybrid energy storage system in wind farms, incorporating various energy storage application functions such as …

Interaction Between Electric Vehicles And Power‑Transportation Coupled Networks: Current Status, Challenges And Development Trends, Jiayan Liu, Zukun Li, Chang Li, Yong Li

Journal of Electric Power Science and Technology

With the widespread popularization of electric vehicles (EVs) and the increasing level of electrification in transportation, there is a growing trend of deep coupling between the distribution grid and the transportation network. Achieving efficient interaction between EVs and the power-transportation coupled network can effectively enhance the stability of grid operation and alleviate congestion in the transportation network, thus becoming a research hotspot in the fields of power systems and EVs. This paper provides a comprehensive introduction to the basic concept of the power-transportation coupled network and delves into three key areas: modeling and state prediction of the power-transportation coupled system, …

Optimized Design Of High Frequency Ice Melting Power Supply Parameters Based On Nsga‑Ⅱ, Han Du, Ci Tang, Min Luo, Jiayi Wang, Zhenzhong Wang, Xuyi Kuang, Yile Zhang

Journal of Electric Power Science and Technology

Transmission line ice-covering accidents occur frequently in winter in China, and the high-frequency ice-melting method based on dielectric loss and skin effect has significant advantages over traditional AC-DC ice-melting heat generation. Aiming at the design problems of frequency and voltage of ice melting power supply in high frequency and high voltage online ice melting, a NSGA-Ⅱ based high-frequency ice melting power supply parameters design method considering line constraints is proposed. Firstly, based on the uniform transmission line theory, the equivalent transmission line circuit model of the ice-covered wire is established; secondly, from the engineering reality and combined with the principle …

Optimal Operation Strategy Of Integrated Energy Virtual Power Plant Based On Production Priority Of Carbon Emission, Fengren Yang, Hong Wang, Zhijie Wang

Journal of Electric Power Science and Technology

With the continuous development of the integrated energy trading market, the issue of uncontrollable carbon emissions has become increasingly prominent. To minimize carbon emissions in the integrated energy trading market, this paper first constructs a system configuration for an electricity-heat-cooling-gas integrated energy virtual power plant, and establishes a demand conversion model and a carbon emission production priority index for it. Next, a comprehensive energy trading allocation model based on carbon emission production priority is developed. Then, based on the determined energy trading volumes, the pricing and demand response strategies for various energies are optimized with the goal of maximizing the …

Fractional‑Order Integral Sliding Mode Control Strategy Based On Mmc Under Unbalanced Grid Conditions, Xuhong Yang, Chun Yuan, Fengwei Qian, Congcong Yin, Qiming Cheng

Journal of Electric Power Science and Technology

To enhance the system performance of the modular multilevel converter (MMC) under unbalanced grid conditions, this paper proposes a fractional order integral sliding mode control (FO-I-SMC) strategy. Firstly, the topology of the MMC is analyzed, and the fundamental frequency external characteristic equations of positive- and negative-sequence voltages and output currents, as well as the double frequency internal characteristic equations of positive-, negative-, and zero-sequence circulating currents, are derived. Secondly, combining the control objectives with the mathematical model of the MMC, a fractional order sliding mode controller is designed for application in unbalanced grid voltages. This controller aims to reduce the …

Optimization Strategy For Energy Storage Configuration In High Proportion Wind Power System Considering Frequency Safety Constraints, Jianhua Sun, Jiaxu Wang, Xiaoyong Du, Chunsun Tian, Junwei Qin, Changhui Guo, Tingtao Wang, Shihong Miao

Journal of Electric Power Science and Technology

In recent years, the large-scale integration of wind turbines, characterized by strong uncertainty and weak support capability, has posed significant challenges to the frequency security of power systems. To enhance the stable operation capability of power systems with a high proportion of wind power, this paper proposes an optimal energy storage allocation strategy considering frequency security constraints. Firstly, the multi-agent frequency response expression for power systems with a high proportion of wind power is derived, and a dynamic frequency response model for the entire system is established. Secondly, aiming to minimize the annual total cost of the power system, an …

Identification Of Grid-Connected Units With The Weakest Small‑Signal Stability In Multiple Renewable Energy Stations Based On Generalized Nyquist Criterion, Bo Chen, Qi Si, Yanhong Chen, Xiang Tao, Kai Wang, Xiaojuan Zhu, Zhiping Wu, Yongsheng Zhang

Journal of Electric Power Science and Technology

The integration of a large number of renewable energy grid-connected converters into the power grid can easily trigger small-signal instability, posing a serious threat to the safety and stability of the system. The existing small-signal stability analysis using the impedance method, based on a multi-machine equivalent mechanism, can only provide an analysis of the factors influencing stability and cannot identify the key weak grid-connected units that affect stability. This paper proposes a method for identifying small-signal stability weak grid-connected units in a renewable energy multi-site system based on the generalized Nyquist criterion (GNC). Firstly, based on the stability analysis approach …

Research On Fault Diagnosis Method For Photovoltaic Array Based On Goa-Svm, Shuai Yang, Wenwei Zeng, Lingyun Yang, Rui Huang, Mouhai Liu, Qinyi Yi, Yunpeng Gao

Journal of Electric Power Science and Technology

The output power of photovoltaic (PV) arrays exhibits strong randomness and volatility. In the event of a fault, it can severely impact the safety and stable operation of the power system. Addressing the challenges of low accuracy and slow convergence in current PV fault diagnosis, this paper proposes a PV array fault diagnosis method based on the grasshopper optimization algorithm-support vector machine (GOA-SVM) model. Firstly, an equivalent circuit model of the PV array is established to analyze the variation characteristics of the PV array's voltage-current curve. Secondly, considering environmental factors and the nonlinear changes in the scale of the PV …

Analysis Model Of Harmonic Power Flow For Single‑Phase Photovoltaic Converters Considering Frequency Coupling, Bo Gao, Fuchang He, Jian Han, Zenwen Li, Yongxiang Yu

Journal of Electric Power Science and Technology

Single-phase photovoltaic inverters are widely used in distribution systems, and studying their harmonic models is of great significance for harmonic power flow analysis, harmonic interaction effects, and power system stability. Firstly, by analyzing the interaction mechanism between the grid and the inverter, as well as the harmonic conduction on the AC- and DC-side of the inverter, the impedance formulas of the single-phase photovoltaic inverter under different harmonics are derived. Secondly, the frequency coupling mechanism of harmonic impedance is analyzed in conjunction with the control loop, and the harmonic coupling impedance matrix model and equivalent Thévenin circuit of the single-phase inverter …

Prediction Method Of Short‑Term Pv Output Power Based On Pca‑Vmd‑Mvo‑Svm, Gang Zou, Bin Zhao, Qiang Luo, Gao Liang, Li Wang

Journal of Electric Power Science and Technology

To enhance the accuracy and reliability of short-term photovoltaic (PV) output power forecasting, a hybrid model is proposed, which integrates principal component analysis (PCA), variational mode decomposition (VMD), and multi-verse optimizer (MVO) to optimize a support vector machine (SVM) for PV output power prediction. Initially, PCA's data analysis capabilities and VMD's data decomposition performance are leveraged to reduce the dimensionality and decompose the multidimensional training data. Subsequently, the extracted dataset is fed into an SVM prediction model optimized by the MVO algorithm to obtain PV output power forecast components for different intrinsic modes. Finally, the results of these forecast components …

A Multi‑Energy Pricing Model For Capacity Markets Considering Generating Capacity Adequacy, Mingyuan Chen, Dong Mo, Qixing Liu, Qi Zou, Yanjie Liang

Journal of Electric Power Science and Technology

With the high proportion of renewable energy generation such as wind, solar, and hydro power integrated into the power system, the low cost of renewable energy generation poses a significant challenge to the cost recovery of traditional thermal power units, resulting in an increasing number of thermal power units exiting the capacity market. Additionally, as renewable energy generation primarily depends on weather conditions, it cannot guarantee sufficient generation capacity during peak load periods. A reasonable pricing mechanism in the capacity market is crucial to address this issue. In response, a multi-energy trading model that considers both the capacity market pricing …

Analysis Of Investment Strategies For Electric Vehicle Charging Stations, Hongcheng Zhang, Bing Yan, Chenjun San, Xuan Cao, Shunran Ye, Xinhua Zhang

Journal of Electric Power Science and Technology

The increasing number of electric vehicles presents opportunities for investment in public charging stations, but uncertainties such as competition and electricity price fluctuations elevate the risks associated with these investment projects. Considering the random fluctuations in the marginal contribution per unit of charging and the utilization rate of charging stations, a real options model is constructed. By solving this model, the investment threshold for charging stations under the condition of maximizing expected investment value is obtained. Using this investment threshold condition, investment strategies are discussed in two scenarios: random fluctuations in charging service fees and the integration of energy storage …

Optimal Dispatching Of Integrated Energy Systems With Diverse Demand Response And Multifaceted Hydrogen Utilization Under Green Certificate‑Carbon Joint Mechanism, Shanshan Liu, Kerui Li, Baikang Liu, Yan Zhang, Zixin Wen

Journal of Electric Power Science and Technology

With the continuous advancement of new power systems and energy interconnection, building an efficient, low-carbon, and economical energy supply system is crucial for the development of the dual carbon strategy. To this end, this paper proposes an optimized operation strategy for an integrated energy system (IES) that considers multi-type demand response and diverse utilization of hydrogen under a joint mechanism of green certificate and carbon trading. Firstly, to fully leverage the regulatory capabilities of demand-side resources, a multi-type demand response model is constructed, encompassing price-based, incentive-based, and substitution-based responses. Secondly, considering the clean nature of hydrogen, a diverse utilization model …

A Multi‑Port Energy Router For Distribution Networks With Single‑Phase Grounding Fault Regulation, Feiyue Zhu, Shiping Su, Chenyu Wu, Xiong Li

Journal of Electric Power Science and Technology

The energy router is a core device in the field of the energy internet, and its circuit topology enables unified distribution of new energy sources, energy storage, and various loads. Currently, energy routers lack the capability to restore power distribution networks after faults. A multi-port energy router (MP-ER) is proposed in this paper, which achieves fault regulation and new energy accommodation. Firstly, the topology and principles of the MP-ER are introduced, and based on its overall structure, a control strategy is proposed that utilizes the DC bus voltage as the primary signal and implements decentralized control for each port. Secondly, …