451 research outputs found
Two sufficient conditions in frequency domain for Gabor frames
AbstractTwo sufficient conditions for the Gabor system to be a frame for L2(R) are presented in this note. The conditions proposed are stated in terms of the Fourier transforms of the Gabor system’s generating functions. It is also shown that these conditions are better than the known result
Ancillary Service Capacity Optimization for Both Electric Power Suppliers and Independent System Operator
Ancillary Services (AS) in electric power industry are critical to support the transmission of energy from generators to load demands while maintaining reliable operation of transmission systems in accordance with good utility practice. The ancillary services are procured by the independent system operator (ISO) through a process called the market clearing process which can be modeled by the partial equilibrium from the ends of ISO. There are two capacity optimization problems for both Market participants (MP) and Independent System Operator (ISO). For a market participant, the firm needs to determine the capacity allocation plan for various AS to pursue operating revenue under various uncertainties which can never be accurately estimated. We thereby employ a heuristic named “resource reservation” to suggest two types of bids, the regular and the must-win for a market participant to pursue higher expected revenue and satisfactory performance in terms of revenue under the worst case scenario. Meanwhile, the ISO, needs to determine the total amount of capacity required to guarantee the overall reliability of the transmission system. Our numerical experiment is based on our industrial partner’s operational data and the simulation result suggests that our proposed methods would greatly outperform the deterministic methods in terms of the profitability for a market participant and the ISO’s entire system’s reliability
Empirical study of Android test generation tools on an industrial app
Given the ever increasing number of research tools to automatically generate inputs to test Android applications (or simply apps), researchers recently asked the question “Are we there yet?” (in terms of the practicality of the tools). In particular, researchers conduct an empirical study on existing testing techniques and tools on open-source Android apps. In this thesis, we present two significant extensions of that study. First, we conduct the first industrial case study of applying existing available testing tools against WeChat, a popular messenger app with over 800 million monthly active users. Second, we study the characteristics of covered activities achieved by testing tools to show which tools can be used in combination with other tools to achieve an optimal activity coverage. We also study the reasons why some activities are covered by only a particular testing tool to help app or tool developers improve their testing tools. Furthermore, we manually categorize not-covered activities to provide insightful information about the not-covered code entities. Such categorization will motivate app developers to spend additional resources during their testing efforts to cover such activities
Low Carbon Energy Policy Research
AbstractCase study of Korea, Low carbon energy efficiency labeling schemes (Energy Efficiency Label and Standard Program, High efficiency Appliance Certification Program, e-Standby Program) play a key role in carrying out the energy efficiency improvement policy in the appliances and equipment sector in Korea. Korea operates these Programs in an effort to improve energy efficiency in appliances and equipments. Mandatory energy efficiency standard which bans production and sales of low energy efficiency products which fall below the minimum energy performance standard. Ministry of Knowledge of Economy (MKE) and Korea Energy Management Corporation (KEMCO) is the key organizations in implementing energy efficiency standards and labeling. National energy efficiency efforts can be realized through energy efficiency improvements with the successful implementation of an energy efficient appliances dissemination policy and the phase out of low efficiency appliances. Through the implementation of the Energy Efficiency Label and Standard Program (1992), High-efficiency Appliance Certification Program (1996) and e-Standby Program (1999), significant energy efficiency improvements have been achieved, and 1.37 billion USD worth of energy savings
An Approximate Dynamic Programming Approach to Vehicle Platooning Coordination in Networks
Platooning connected and autonomous vehicles (CAVs) provide significant
benefits in terms of traffic efficiency and fuel economy. However, most
existing platooning systems assume the availability of pre-determined plans,
which is not feasible in real-time scenarios. In this paper, we address this
issue in time-dependent networks by formulating a Markov decision process at
each junction, aiming to minimize travel time and fuel consumption. Initially,
we analyze coordinated platooning without routing to explore the cooperation
among controllers on an identical path. We propose two novel approaches based
on approximate dynamic programming, offering suboptimal control in the context
of a stochastic finite horizon problem. The results demonstrate the superiority
of the approximation in the policy space. Furthermore, we investigate
platooning in a network setting, where speed profiles and routes are determined
simultaneously. To simplify the problem, we decouple the action space by
prioritizing routing decisions based on travel time estimation. We subsequently
employ the aforementioned policy approximation to determine speed profiles,
considering essential parameters such as travel times. Our simulation results
in SUMO indicate that our method yields better performance than conventional
approaches, leading to potential travel cost savings of up to 40%.
Additionally, we evaluate the resilience of our approach in dynamically
changing networks, affirming its ability to maintain efficient platooning
operations
Forsythiaside A inhibits hydrogen peroxide-induced inflammation, oxidative stress, and apoptosis of cardiomyocytes
Purpose: To investigate the effect of forsythiaside A on heart failure.Methods: An in vitro cell model of myocardial injury was established by incubating H9c2 primary cardiomyocytes with hydrogen peroxide (H2O2). Apoptosis was measured by flow cytometry. Expression of inflammatory factors, including tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), was determined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and enzymelinkedimmunosorbent assay (ELISA). Oxidative stress was evaluated by measuring malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) levels by ELISA.Results: Incubation with H2O2 increased H9c2 cell apoptosis (p < 0.001). Treatment with forsythiaside A reduced Bax expression and enhanced Bcl-2 expression which suppressed apoptosis of H2O2- induced H9c2 cells. Forsythiaside A also attenuated the H2O2-induced increase in TNF-α and IL-6expressions in H9c2 cells (p < 0.001). The H2O2-induced increase in MDA and decrease in SOD and GSH-Px in H9c2 cells were reversed by treatment with forsythiaside A. IκBα protein expression was downregulated, whereas p65 phosphorylation (p-p65), p-IκBα, nuclear factor erythropoietin-2-related factor 2 (Nrf2), and heme oxygenase 1 (HO-1) were upregulated in H2O2-induced H9c2 cells. Forsythiaside A increased IκBα, Nrf2, and HO-1 expression and decreased p-p65 and p-IκBα expression in H2O2-induced H9c2 cells.Conclusion: Forsythiaside A exerts anti-inflammatory, anti-oxidant, and anti-apoptotic effects against H2O2-induced H9c2 cells through inactivation of NF-κB pathway and activation of Nrf2/HO-1 pathway. These results support the potential clinical application of forsythiaside A for the treatment of heart failure
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