Operational concepts for grid services using electric vehicles

The European electricity grid is subject to increasing stresses due to increasing share of volatile renewable energy technologies. These technologies, coupled with higher volatility in demand, pose challenges to the stability and security of the European grid, erstwhile dominated by large and relatively reliable conventional generation. As the contribution of wind and photovoltaic generation increases in the energy mix, it demands an assessment of the corresponding risk to frequency stability and possible preventive measures. Uncontrolled charging of the increasing number of electric vehicles in Germany also demands a thorough investigation of methods for their integration in the electricity grid to not only improve grid frequency stability but also to provide secondary benefits to electric vehicle users. This work analyzes the load frequency control systems for their suitability for integration of electric vehicles and the impact of increase in volatile renewable energy on frequency stability for the case of Germany, showing a significant increase in reserve requirements. Evaluation of alternative approaches to load frequency control on the basis of infrastructure requirements shows that introduction of an aggregator of distributed energy resources can significantly reduce the overall infrastructure requirements for grid operators. The operational concepts herein proposed are evaluated using several case studies for optimizing the use of electric vehicles for grid flexibility services by taking into account the usage requirements of the vehicle owner and supply requirements of grid services.Das europäische Stromnetz ist aufgrund des steigenden Anteils volatiler erneuerbare Energiequellen einer zunehmenden Belastung ausgesetzt. Diese Technologien, in Ver-bindung mit einer höheren Volatilität der Nachfrage, stellen eine Herausforderung für die Stabilität und Sicherheit des europäischen Netzes dar, das früher von einer zentrali-sierteren Erzeugung in großen und relativ zuverlässigen konventionellen Kraftwerken geprägt war. Mit zunehmendem Beitrag der Wind- und Photovoltaikerzeugung am Energiemix ist eine Bewertung des Risikos für die Frequenzstabilität und mögliche Prä-ventivmaßnahmen erforderlich. Die ungesteuerte Aufladung der zunehmenden Anzahl von Elektrofahrzeugen in Deutschland erfordert auch eine gründliche Untersuchung der Methoden für ihre Integration in das Stromnetz, um nicht nur die Stabilität der Strom-netzfrequenz zu verbessern, sondern auch einen sekundären Nutzen für die Elektrofahr-zeug-Nutzer zu erzielen. Diese Arbeit analysiert die Lastfrequenzregelungssysteme auf ihre Eignung zur Integration von Elektrofahrzeugen ins Stromnetz sowie die Auswir-kungen der Erhöhung des Anteils von volatilen erneuerbaren Energien auf die Frequenz-stabilität in Deutschland, und zeigt einen deutlichen Anstieg der Anforderungen an Re-servekapazität. Die Bewertung alternativer Ansätze zur Lastfrequenzsteuerung auf der Grundlage von Infrastrukturanforderungen zeigt, dass die Einführung eines verteilten Energieressourcen Aggregators den gesamten Infrastrukturbedarf der Netzbetreiber deutlich reduzieren kann. Die hierin vorgeschlagenen Betriebskonzepte werden anhand mehrerer Fallstudien zur Optimierung des Einsatzes von Elektrofahrzeugen für Flexibili-tätsdienstleistungen im Stromnetz unter Berücksichtigung der Anforderungen der Fahr-zeughalter und des Versorgungsbedarfs von Netzdiensten bewertetThis thesis deals with the challenges to frequency stability in the European electricity grid posed by the increasing share of renewable energy resources and electric vehicles. It evaluates European load frequency control systems for their suitability for integration of electric vehicles and the impact of increase in photovoltaic and wind power on frequency stability for the case of Germany, demonstrating a consequent significant increase in frequency control reserve requirements. Evaluation of alternative approaches to load frequency control shows that introduction of an aggregator of distributed energy resources can also significantly reduce the overall infrastructure requirements for grid operators. The operational concepts herein proposed are evaluated using several case studies for optimizing the use of electric vehicles for grid flexibility services by taking into account the user behavior of vehicle owners and supply requirements of these grid services

Domain Generalisation with Bidirectional Encoder Representations from Vision Transformers

Domain generalisation involves pooling knowledge from source domain(s) into a single model that can generalise to unseen target domain(s). Recent research in domain generalisation has faced challenges when using deep learning models as they interact with data distributions which differ from those they are trained on. Here we perform domain generalisation on out-of-distribution (OOD) vision benchmarks using vision transformers. Initially we examine four vision transformer architectures namely ViT, LeViT, DeiT, and BEIT on out-of-distribution data. As the bidirectional encoder representation from image transformers (BEIT) architecture performs best, we use it in further experiments on three benchmarks PACS, Home-Office and DomainNet. Our results show significant improvements in validation and test accuracy and our implementation significantly overcomes gaps between within-distribution and OOD data.Comment: 4 pages, accepted at the Irish Machine Vision and Image Processing Conference (IMVIP), Galway, August 202

Factors Influencing Students' Learning at KASB Institute of Technology

The research article looks into the psychological and other characteristics that play a role in students’ learning ability. In all the observations we have found some students performing better than the others, this display of performance in their studies implies the presence of certain factors which are different from others or play a role in their better learning capabilities. These factors may be present in students, teachers, institutions and others. This article is an attempt to highlight those factors which may be required on part of the students, teachers, institutions and others that may or may not play a significant role in enhancing students’ learning capabilities, the sample of 103 is used to infer the significance of these factors. Through research we were able to answer as per students, punctuality of the teacher is somewhat important in enhancing learning. Clarity of speech was considered an insignificant feature. The most preferred quality of the teacher which is responsible for ranking a teacher as the best teacher is cooperativeness. Another finding was the relationship between CGPA obtained and consulting teacher outside class, which we concluded that there is a strong relationship between consulting teacher and obtaining good CGPA. Lastly we found that time spend in library has no significant association with understanding of topic when taught.Students’ Learning, Students and Teacher Characteristics

Metabolic syndrome: frequency and gender differences at an out - patient clinic

Objective: To determine the frequency of metabolic syndrome among patients attending an out-patient clinic of a teaching hospital and to compare the clinical features regarding metabolic syndrome among males and females.Study Design: Cross-sectional study.Place and Duration: Aga Khan University Hospital (AKUH), Executive and Family Medicine Clinics, from December 2004 to April 2005.Patients and Methods: All adults, above 25 years, attending the clinics for an executive check-up and giving informed consent were included in the study. Data was collected through a structured questionnaire administered to those eligible to participate. Metabolic syndrome was defined according to ATP-III guidelines.Results: There were 250 participants in this study. Mean age of study participants was 48.94 (SD10.62) years, while approximately two-thirds, 157 (62.8%), were male. Metabolic syndrome (those who had 3 or more risk factors) was present in 35.2% of adults. Fasting blood sugar level was raised in 36.4% of study participants while significant number of participants (78.8%) had a body mass index (BMI) \u3eor= 25 (p = 0.02).Conclusion: Frequency of metabolic syndrome was significantly high in this study with preponderance of males and prevalence similar to that observed in developed countries. Majority of patients had obesity and high fasting blood sugar levels. Males demonstrated higher levels of triglycerides and low levels of high-density lipoprotein (HDL) compared to females while blood pressure reading was observed to be the same in both males and females

Dimethyl (2-hydr­oxy-4-phenyl­but-3-en-2-yl)phospho­nate

In the title compound, C12H17O4P, the phenyl­butenyl group is disordered over two sets of sites with an occupancy ratio of 0.755 (12):0.245 (12). In the crystal, inversion dimers linked by pairs of O—H⋯O hydrogen bonds occur, forming R 2 2(10) ring motifs. The packing is consolidated by weak C—H⋯π inter­actions

Renewable Energy-Based Distributed Generation in Pakistan: Status, Importance, and Electrification Opportunities

Renewable energy improves energy security, provides reliable power supply, and ensures fuel diversification. It also offers a solution to the problem of circular debt which has lately become a major concern for the power sector of Pakistan. At present, the share of renewable energy resources in the energy mix is significantly low and the Government of Pakistan (GoP) is urging the drivers and enablers to boost clean and green energy generation and distribution. The power sector, especially the distribution companies, are facing numerous issues in transmission and distribution of power, and recovery of losses. Distributed generation (DG) can play a vital role in overcoming these issues. The effectiveness of solar PV systems, the active role of the capital market, and environmental concerns are among the major factors that prompt the adoption of net-metered solar systems. Apart from traditional alternate energy sources through sunlight and wind, Pakistan has enormous potential for biomass fuel if it could develop proper facilities for biomass-based electrification. For issues related to grid coverage and technical losses in far-flung rural areas, mini-, and micro-hydro power-based distributed generation can serve the purpose. Distributed generation can play a vital role in steering the national power sector toward power sources that offer clean, green, and cheap energy. Huge opportunities for prosperity in rural areas can be also created through carbon-free atmosphere and a sustainable energy sector

Vision based machine learning algorithms for out-of-distribution generalisation

There are many computer vision applications including object segmentation, classification, object detection, and reconstruction for which machine learning (ML) shows state-of-the-art performance. Nowadays, we can build ML tools for such applications with real-world accuracy. However, each tool works well within the domain in which it has been trained and developed. Often, when we train a model on a dataset in one specific domain and test on another unseen domain known as an out of distribution (OOD) dataset, models or ML tools show a decrease in performance. For instance, when we train a simple classifier on real-world images and apply that model on the same classes but with a different domain like cartoons, paintings or sketches then the performance of ML tools disappoints. This presents serious challenges of domain generalisation (DG), domain adaptation (DA), and domain shifting. To enhance the power of ML tools, we can rebuild and retrain models from scratch or we can perform transfer learning. In this paper, we present a comparison study between vision-based technologies for domain-specific and domain-generalised methods. In this research we highlight that simple convolutional neural network (CNN) based deep learning methods perform poorly when they have to tackle domain shifting. Experiments are conducted on two popular vision-based benchmarks, PACS and Office-Home. We introduce an implementation pipeline for domain generalisation methods and conventional deep learning models. The outcome confirms that CNN-based deep learning models show poor generalisation compare to other extensive methods

A novel track-drive mobile robotic framework for conducting projects on robotics and control systems

This paper presents a novel robotic framework to help students to practically grasp the concepts of Robotics and Control Systems in a laboratory environment. The framework is centered on a robotic rover having two tank-like tracks which permit locomotion on uneven terrains. The sensory system consists of encoders for position feedback while the actuation system comprises of six precise DC motors. To enhance the learning outcomes of students and to permit readily realizaion of applications, developed software library supports three different command levels. The efficacy of the framework has been demonstrated by presenting a list of projects conducted on the framework. In particular, as a case-study, a project titled tether tracking and control of robotic rover has been detailed in the paper with presentation of experimental results. The pilot study indicated that incorporating the framework in robotics laboratory resulted in an efficient methodology of imparting interdisciplinary knowledge to engineering students. Additionally, the framework finds its potential in research of advanced robotic and control algorithms

Polymer Stabilized Metal Nanoparticles for Catalytic Degradation of Methylene Blue in Water

Methylene blue is highly toxic and releases from various industries. It must be transformed into less toxic compounds. The Core-Shell microgels p (Pst core), Pstcore-NIPMamm-MAa and Ag in Pst-p NIPMamm-MAa have been synthesized using the Core-Shell hybrid micro gelling NIPMamm-MAa emulsion polymerization process. The 0.086mM, MB 6.2mM NaBH4 and 0.2916 mg / mL catalysts in the cuvette were measured using UV-visible spectrophotometers. Spectrums were measured at a one-minute interval. The peak at 600 nm steadily decreased over time and was completely eliminated after 11 minutes. Without the catalyst, MB decreases with NaBH4 which showed that the reaction decreases were slow and MB very high within 120 minutes. The Psty core of FT-IR core microgels, pNIpmam-MMAA, and Ag-pNIpmam-MAA core microgels are hybrids. At 2955 and 2845 cm−1 FT-IR spectra, Psty NiPMaM – MaA and Ag-p NiPMaM – MaA were used for core shell microgels, with C-H vibrations expanding the aromatic ring. In this study degradation of Methylene were carried out with Ag- Nanocomposites at different interval of time to check the degradation at minimum time. The degradation of MB dye were carried out with Ag- Nano composites at different interval of time to check the degradation at minimum time

Residents’ Perception Of Surgical Theatre Educational Environment At Public Hospitals Of Rawalpindi - A Steem Survey

INTRODUCTION: The experience in the operation theatres is pivotal for surgical education. A measure of the educational environment in the operating room as perceived by residents would assist educators and trainees in gauging the quality of the learning occurring within their institute.     METHODS:  A cross-sectional survey using the surgical theatre educational environment measure (STEEM) 40-item inventory to measure theatre learning environment perception of surgery and allied residents in public sector hospitals of Rawalpindi. Internal reliability of the inventory was assessed using the Cronbach α coefficient. P≤ 0.05 was considered significant.   RESULTS:  107 respondents were included in the study. Mean score of the survey was 133.7± 20.2. No significant differences in perception were found among residents at different stages and gender, except in learning subscale of the inventory for both gender and residents and the teaching and training subscale among residents at different levels. The inventory showed a high internal consistency with a Cronbach α of 0.851.   CONCLUSION: Surgical training and education have still a long way to go in the public sector. Much needed collaborations with education specialist and senior surgeons is required. Interval collection of feedback and perceptions of the educational environment is also necessary