https://hdl.handle.net/20.500.12809/57 Fri, 03 Jul 2026 18:45:55 GMT 2026-07-03T18:45:55Z https://hdl.handle.net/20.500.12809/11227 Cost-optimal day-ahead scheduling of multi-energy systems with micro-mobility Noorzad, Najmuddin; Taşcıkaraoğlu, Akın; Catalao, Joao P. S The escalating demand for energy necessitates the exploration of innovative solutions. In this context, Multi-Energy Systems (MESs) emerge as a promising and efficient approach for delivering diverse energy services, such as heating, cooling, and electricity, to end users. Determining the optimal configuration of an MES requires a holistic evaluation encompassing its constituent components, prevailing energy prices, and load demands. This study investigates an MES incorporating Combined Heat and Power (CHP) units, Heat Pumps (HPs), Renewable Energy Sources (RESs), Community Energy Storage (CES), multi-energy demands, and micro-mobility options such as electric scooters (e-scooters). The primary objective of the study is to minimise operational costs and improve system efficiency while satisfying all energy demands. This objective is pursued by evaluating the optimal MES operation under different electricity tariffs, adhering to associated constraints throughout the operation period. Furthermore, the cost-effectiveness of e-scooters and their charging impacts on the power network operation are assessed. The proposed strategy is thoroughly implemented across case studies, and simulation results show a 21.05% reduction in operational costs compared to the base case. Thu, 01 Jan 2026 00:00:00 GMT https://hdl.handle.net/20.500.12809/11227 2026-01-01T00:00:00Z https://hdl.handle.net/20.500.12809/11216 A Novel and Compact Subnanosecond Pulse Generator Using Complementary RF BJTs Telli, Emrah; Yıldırım, Bahadır Süleyman A novel and compact subnanosecond pulse generator circuit has been designed and built using ultra high frequency (UHF) band negative-positive-negative (NPN) and positive-negative-positive (PNP) RF bipolar junction transistors (BJTs). The simulated and calculated output pulse amplitude is about 1.1 V on a 50-Omega load, and the pulsewidth is about 210 ps. The proposed design does not have a base bias, as in conventional single-transistor step-recovery effect (SRE) BJT pulse generators. The dual-transistor action produces very short pulsewidths without base bias. Fabricated prototypes have been measured using a spectrum analyzer. Simulations and measurements are found to be in good agreement. Thu, 01 Jan 2026 00:00:00 GMT https://hdl.handle.net/20.500.12809/11216 2026-01-01T00:00:00Z https://hdl.handle.net/20.500.12809/11068 Formal Verification of Bit-Vector Invertibility Conditions in Coq Ekici, Burak; Viswanathan, Arjun; Zohar, Yoni; Tinelli, Cesare; Barrett, Clark Stanford University We prove the correctness of invertibility conditions for the theory of fixed-width bit-vectors—used to solve quantified bit-vector formulas in the Satisfiability Modulo Theories (SMT) solver cvc5— in the Coq proof assistant. Previous work proved many of these in a completely automatic fashion for arbitrary bit-width; however, some were only proved for bit-widths up to 65, even though they are being used to solve formulas over larger bit-widths. In this paper we describe the process of proving a representative subset of these invertibility conditions in Coq. In particular, we describe the BVList library for bit-vectors in Coq, our extensions to it, and proofs of the invertibility conditions. Sun, 01 Jan 2023 00:00:00 GMT https://hdl.handle.net/20.500.12809/11068 2023-01-01T00:00:00Z https://hdl.handle.net/20.500.12809/11044 Investigations of the Friction and Wear Resistance of the Natural Fiber-Reinforced Polyamide Composites Doğru, Alperen; Can Kaymaz, İbrahim; Kandemir, Miray Batikan; Seydibeyoğlu, Mehmet Özgür The search for natural and biobased materials to create a sustainable future has led many scientists to conduct research on natural-fiber-reinforced composites. Natural fibers have been used for thousands of years, but in the recent decades, they have been used in polymer composites as a reinforcement and/or filler. Natural fibers provide abundant resource in various countries through many forms. The use of natural fiber for structural composites is important in creating important new uses. Biobased materials are becoming more prominent in various applications including automotive parts and many other machinery. For the mechanical parts, friction and wear has been one of the most important topics for long-term performance of these products. In this book chapter, summary of natural fibers and their applications in polyamide composites has been well documented. The use of these composites has been investigated in terms of friction and wear properties. The wear and friction topics are commonly less studied in academic area, but they have a very significant importance for the industry. It is expected that this chapter will highlight the industrial use of these materials for long-term uses. Sun, 01 Jan 2023 00:00:00 GMT https://hdl.handle.net/20.500.12809/11044 2023-01-01T00:00:00Z