• 한국수소및신에너지학회논문집
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• 제23권6호
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• pp.604-611
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• 2012

For the commercialization of fuel cell powered vehicle, it is highly important to improve the performance and efficiency of an automotive polymer electrolyte membrane fuel cell (PEMFC) system. The performance and efficiency of PEMFC systems are significantly influenced by their operating conditions. Among these conditions, the system operating pressure is considered as the one of the main factors. In this study, to investigate the effects of operating pressure on the performance and efficiency of automotive PEMFC systems, two types of high-pressure operating PEMFC systems adopting two different compressors (i. e. different performance maps) are modeled by using MATLAB/Simulink environment. The PEMFC system efficiency and parasitic compressor power are mainly analyzed and compared for the two types of high-pressure operating PEMFC systems under the same system net power conditions. It is expected that this kind of study can contribute to provide basic insight into the operating strategies of high-pressure operating PEMFC systems for automotive use.

• Asia pacific journal of information systems
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• 제34권1호
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• pp.150-190
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• 2024

This article proposes a framework to elucidate the structural dynamics of the generative AI ecosystem. It also outlines the practical application of this proposed framework through illustrative policies, with a specific emphasis on the development of the Korean generative AI ecosystem and its implications of platform strategies at AI platform-squared. We propose a comprehensive classification scheme within generative AI ecosystems, including app builders, technology partners, app stores, foundational AI models operating as operating systems, cloud services, and chip manufacturers. The market competitiveness for both app builders and technology partners will be highly contingent on their ability to effectively navigate the customer decision journey (CDJ) while offering localized services that fill the gaps left by foundational models. The strategically important platform of platforms in the generative AI ecosystem (i.e., AI platform-squared) is constituted by app stores, foundational AIs as operating systems, and cloud services. A few companies, primarily in the U.S. and China, are projected to dominate this AI platform squared, and consequently, they are likely to become the primary targets of non-market strategies by diverse governments and communities. Korea still has chances in AI platform-squared, but the window of opportunities is narrowing. A cautious approach is necessary when considering potential regulations for domestic large AI models and platforms. Hastily importing foreign regulatory frameworks and non-market strategies, such as those from Europe, could overlook the essential hierarchical structure that our framework underscores. Our study suggests a clear strategic pathway for Korea to emerge as a generative AI powerhouse. As one of the few countries boasting significant companies within the foundational AI models (which need to collaborate with each other) and chip manufacturing sectors, it is vital for Korea to leverage its unique position and strategically penetrate the platform-squared segment-app stores, operating systems, and cloud services. Given the potential network effects and winner-takes-all dynamics in AI platform-squared, this endeavor is of immediate urgency. To facilitate this transition, it is recommended that the government implement promotional policies that strategically nurture these AI platform-squared, rather than restrict them through regulations and stakeholder pressures.

• KIEE International Transactions on Power Engineering
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• 제5A권4호
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• pp.396-402
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• 2005

In an electricity market with imperfect competition, participants devise bidding plans and transaction strategies to maximize their own profits. The market price and the quantity are concerned with the operation reserve as well as the bidding system and demand curves in an electricity market. This paper presents a market model combined by an energy market and an operating reserve market. The competition of the generation producers in the combined market is formulated as a gaming of selecting bid parameters such as intersections and slopes in bid functions. The Nash Equilibrium (NE) is analyzed by using bi-level optimization; maximization of Social Welfare (SW) and maximization of the producers' profits.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 추계학술대회 논문집
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• pp.291-296
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• 2001

The computerized automation of modern manufacturing system is tremendously important for the cost reduction. Recently, the automation is being realized by Computer Integrated Manufacturing (CIM) concept and the unmanned factory is the final goal of the automation. The automation of the low level of factory is the most crucial and difficult aspect in total CIM environment since various machines are involved. A cell is defined as a manufacturing group of closely related machineries in the entire factory hierarchy, The management scheme for a cell controller is defined from the software viewpoint. The domain of a cell is designed with tasks(processes) in a multiple-task operating system. The operation of the cell is established by defining schemes for overall control of the cell domain, databases, job scheduling, communications within the domain, user-interface and communications with outside machines. Although the software is developed in a specific operating system and WINDOW facilities, the operating strategies can be applied globally.

• 한국물환경학회지
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• 제23권2호
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• pp.206-215
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• 2007

The objective of this study was to establish the optimal system operating strategies for nitrogen and phosphorus removal through model simulation system built for advanced wastewater treatment targeting on simultaneous temporal/special phase isolation BNR process. The simulation system was built with unit process modules using object modules in GPS-X code. The system was well verified by field experiment data. Simulation study was carried out to investigate performance response to design and operation parameters, i.e. hydraulic retention time (HRT), solids retention time (SRT), and cycle time. The process operated at HRTs of 10~15 hours, longer SRTs, and cycle time of 2 hours showed optimal removal of nitrogen. The HRTs of 10~15 hours, SRTs of 20~25 days, and longer cycle time was optimal for phosphorus removal. Both simulation and field studies showed that optimal operating strategies satisfying both the best nitrogen and phosphorus removals include HRTs ranged 10~15 hours, SRTs ranged 20~25 days, and cycle times of 4~8 hours. The simulation system with modularization of generalized components in BNR processes was, therefore, believed to be a powerful tool for establishing optimal strategies of advanced wastewater treatment.

• 디지털융복합연구
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• 제8권4호
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• pp.19-33
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• 2010

시내버스는 과거 시민들에게 교통편익을 제공하는 가장 대표적인 대중교통수단이었지만 최근 자가용의 급속한 증가와 지하철 건설 등으로 버스 이용자는 감소 추세에 있다. 따라서 시내버스업체의 경영여건은 지속적으로 악화되어 왔으며, 시민에 대한 교통서비스 수준 역시 낮게 평가되어 왔다. 이에 서울과 부산 및 각 광역시를 중심으로 시내버스 운영의 합리화와 지하철과의 연계 등 대중교통 시스템의 공공성과 효율성을 제고하기 위해 시내버스 준공영제를 경쟁적으로 도입하였다. 본 논문은 우리나라 대도시들에서 채택하고 있는 버스준공영제를 중심으로 그 현황과 문제점 및 앞으로의 바람직한 정책방향을 모색하기 위한 연구이다. 먼저 시내버스 운영형태와 외국(미국 뉴욕, 영국 런던, 프랑스 파리, 일본 동경도)의 사례를 먼저 고찰하고 우리나라의 대도시들에서 도입한 시내버스 준공영제의 운영현황, 실시효과 및 문제점들을 분석하였다. 특히 광주광역시의 대중교통현황과 준공영제의 운영 내용과 문제점을 파악하고자 하였다. 이상의 논의를 중심으로 바람직한 대중교통의 정책방향을 제시하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.713-715
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• 2004

In an electricity market with an imperfect competition, participants make plans of biddings and transaction strategies to maximize their own profits. The market price and the quantity are concerned with the operation reserve as well as the bidding system and demand curves in an electricity market. This paper presents a model of the combined market , energy market and operating teserve market. The Nash equilibrium is analyzed by using a hi-level optimization , maximization of Social welfare (SW) and maximization of the producers' profits.

• 경영과학
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• 제11권1호
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• pp.23-37
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• 1994

This paper discusses the methodology for the operational performance of unit-load automated guided vehicles(AGVs) in a flow-shop-type flexible machining and assembly systems (FM/AS). Throughout the paper, AGVs are working as a carrier and mobile workstation. For a double-loop FM/AS, in which one loop is dedicated to machining and the other to assembly, three AGV operating strategies are proposed. Considering the entering interval and travel time of AGVs between workcenters, the strategies are developed to determine the best job sequence which minimizes the makespan and vehicle idle time. Entering times of AGVs and the required minimum number of AGVs are obtained on the basis of the best job sequence. When the number of AGVs are limited, entering times of AGVs are adjusted to maximize the utilization of AGVs.

• 품질경영학회지
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• 제35권1호
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• pp.52-60
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• 2007

The purpose of this study is to explorer some strategies for implementing successfully the qualify management for public policy (PPQM) in local government. Researchers for reaching at the purpose reviewed a literature on QM (or TQM) and PPQM in chapter II and suggested implementing strategies of local government's PPQM in chapter III. Implement strategies of local government's PPQM have to build a framework, establish an operating system, develop a customized PPQM's manual, and develop a capacity of local government's civil servant for implementing the PPQM and then build an evaluating system on the result of the PPQM's implementation in local government.

• 대한전기학회논문지:시스템및제어부문D
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• 제52권5호
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• pp.283-289
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• 2003

This paper proposes an expert system which can determine automatically the shunting routes corresponding to the given shunting works by considering totally the train operating environments in the station. The expert system proposes the multiple shunting routes with priority of selection based on heuristic search strategy. Accordingly, system operator can select a shunting route with the safety and efficiency among the those shunting routes. The expert system consists of a main inference engine and a sub inference engine. The main inference engine determines the shunting routes with selection priority using the segment routes obtained from the sub inference engine. The heuristic rules are extracted from operating knowledges of the veteran route operator and station topology. It is implemented in C computer language for the purpose of the implementation of the inference engine using the dynamic memory allocation technique. And, the validity of the builted expert system is proved by a test case for the model station.