• Title/Summary/Keyword: Storage Strategy

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Energy Management and Performance Evaluation of Fuel Cell Battery Based Electric Vehicle

  • Khadhraoui, Ahmed;SELMI, Tarek;Cherif, Adnene
    • International Journal of Computer Science & Network Security
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    • v.22 no.3
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    • pp.37-44
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    • 2022
  • Plug-in Hybrid electric vehicles (PHEV) show great potential to reduce gas emission, improve fuel efficiency and offer more driving range flexibility. Moreover, PHEV help to preserve the eco-system, climate changes and reduce the high demand for fossil fuels. To address this; some basic components and energy resources have been used, such as batteries and proton exchange membrane (PEM) fuel cells (FCs). However, the FC remains unsatisfactory in terms of power density and response. In light of the above, an electric storage system (ESS) seems to be a promising solution to resolve this issue, especially when it comes to the transient phase. In addition to the FC, a storage system made-up of an ultra-battery UB is proposed within this paper. The association of the FC and the UB lead to the so-called Fuel Cell Battery Electric Vehicle (FCBEV). The energy consumption model of a FCBEV has been built considering the power losses of the fuel cell, electric motor, the state of charge (SOC) of the battery, and brakes. To do so, the implementing a reinforcement-learning energy management strategy (EMS) has been carried out and the fuel cell efficiency has been optimized while minimizing the hydrogen fuel consummation per 100km. Within this paper the adopted approach over numerous driving cycles of the FCBEV has shown promising results.

A Study on Power Trading Methods for in a Hydrogen Residential Model (수소주거모델의 전력 거래 참여 방안 고찰)

  • KISEOK JEONG;TAEYOUNG JYUNG
    • Transactions of the Korean hydrogen and new energy society
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    • v.34 no.2
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    • pp.91-99
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    • 2023
  • Participation in power trading using surplus power is considered a business model active in the domestic energy trade market, but it is limited only if the legal requirements according to the type, capacity, and use of the facilities to be applied for are satisfied. The hydrogen residential demonstration model presented in this paper includes solar power, energy storage system (ESS), fuel cell, and water electrolysis facilities in electrical facilities for private use with low-voltage power receiving system. The concept of operations strategy for this model focuses on securing the energy self-sufficiency ratio of the entire system, securing economic feasibility through the optimal operation module installed in the energy management system (EMS), and securing the stability of the internal power balancing issue during the stand-alone mode. An electric facility configuration method of a hydrogen residential complex demonstrated to achieve this operational goal has a structure in which individual energy sources are electrically connected to the main bus, and ESS is also directly connected to the main bus instead of a renewable connection type to perform charging/discharging operation for energy balancing management in the complex. If surplus power exists after scheduling, participation in power trading through reverse transmission parallel operation can be considered to solve the energy balancing problem and ensure profitability. Consequentially, this paper reviews the legal regulations on participation in electric power trading using surplus power from hydrogen residential models that can produce and consume power, gas, and thermal energy including hybrid distributed power sources, and suggests action plans.

A study on the improvement of distribution system by overseas agricultural investment (해외농업투자에 따른 유통체계 개선방안에 관한 연구)

  • Sun, Il-Suck;Lee, Dong-Ok
    • Journal of Distribution Science
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    • v.8 no.3
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    • pp.17-26
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    • 2010
  • Recently concerns have been raised due to the unbalanced supply of crops: the price of crops has been unstable and at one point the price went up so high that the word Agflation(agriculture+ inflation) was coined. Korea, in particular, is a small-sized country and needs to secure the stable supply of crops by investing in the produce importation at a national level. Investment in foreign produce importation is becoming more important as a measure for sufficient supply of crops, limited supply of domestic crops, weakened farming conditions worldwide, as well as recent changes in the use of crops due to the development of bio-fuels, influence of carbon emission on crops, the price increase in crops, and influx of foreign hot money. However, there are many problems with investing in foreign produce importation: lack of support from the government; lack of farming information and technology; difficulty in securing the capital; no immediate pay-off from the investment and insufficient management. Although foreign produce is originally more price-competitive than domestic produce, it loses its competiveness in the process of importation (due to high tariffs) and poor distribution system, which makes it difficult to sell in Korea. Therefore, investment in foreign produce importation is being questioned for feasibility; to make it possible, foreign produce must maintain the price-competitiveness. Especially, harvest of agricultural products depends on natural and geographical conditions of each country and those products have indigenous properties, so distribution system according to import and export of agricultural products should be treated more carefully than that of other industries. Distribution costs are differentiated into each item and include cost of sorting and wrapping, cost of wrapping materials, cost of domestic transport, cost of international transport and cost of clearing customs for import and export. So transporting and storing agricultural products generates considerable costs compared with other products. Also, due to upgrade of dietary life, needs for stability, taste and visible quality toward food including agricultural products are being raised and wrong way of storage causes decomposition of food and loss of freshness, making the storage more difficult than that in room temperature, so storage and transport in distribution of agricultural products needs specialty. In addition, because lack of specialty in distribution and circulation such as storage and wrapping does not solve limit factors in distance, the distribution and circulation has been limited to a form of import and export within short-distant region. Therefore, need for distribution out-sourcing which can satisfy specialty in managing distribution and circulation and it is needed to establish more effective distribution system. However, existing distribution system of agricultural products is exposed to various problems including problems in distribution channel, making distribution and strategy for distribution and those problems are as follows. First, in case of investment in overseas agricultural industry, stable supply of the products is difficult because areas of production are dispersed widely and influenced by outer factors due to including overseas distribution channels. Also, at the aspect of quality, standardization of products is difficult, distribution system is quite complicated and unreasonable due to long distribution channels according to international trade and financial and institutional support is not enough. Especially, there are quite a lot of ineffective factors including multi level distribution process, dramatic gap between production cost and customer's cost, lack of physical distribution facilities and difficulties in storage and transport due to lack of wrapping containers. Besides, because import and export of agricultural products has been manages under the company's own distribution according to transaction contract between manufacturers and exporting company, efficiency is low due to excessive investment in fixed costs and lack of specialty in dealing with agricultural products causes fall of value of products, showing the limit to lose price-competitiveness. Especially, because lack of specialty in distribution and circulation such as storage and wrapping does not solve limit factors in distance, the distribution and circulation has been limited to a form of import and export within short-distant region. Therefore, need for distribution out-sourcing which can satisfy specialty in managing distribution and circulation and it is needed to establish more effective distribution system. Second, among tangible and intangible services which promote the efficiency of the whole distribution, a function building distribution environment which includes distribution information, system for standard and inspection, distribution finance, system for diversification of risks, education and training, distribution administration and tax system is wanted. In general, such a function building distribution environment is difficult to be changed and supplement innovatively because its effect compared with investment does not appear immediately despite of its necessity. Especially, in case of distribution of agricultural products, as a function of collecting and distributing is performed individually through various channels, the importance of distribution information and standardization is getting more focus due to the problem of repetition of work and lack of specialty. Also, efficient management of distribution is quite difficult due to lack of professionals in distribution, so support to professional education is needed. Third, though effort to keep self-sufficiency ratio of staple food, rice is regarded as important at the government level, level of dependency on overseas of others crops is high. Therefore, plan for stable securing food resources aside from staple food is also necessary. Especially, governmental organizations of agricultural products distribution in Korea are production-centered and have unreasonable structure whose function at the aspect of distribution and consumption is quite insufficient. And development of new distribution channels which can deal with changes in distribution environment and they do not achieve actual results of strategy for distribution due to non-positive strategy for price distribution. That is, it implies the possibility that base for supply will become vulnerable because it does not mediate appropriate interests on total distribution channels such as manufacturers, wholesale dealers and vendors by emphasizing consumer protection excessively in the distribution of agricultural products. Therefore, this study examined fundamental concept and actual situation for our investment to overseas agriculture, drew necessities, considerations, problems, etc. of overseas agricultural investment and suggested improvements at the level of distribution for price competitiveness of agricultural products cultivated in overseas under five aspects; government's indirect support, distribution's modernization and distribution information function's strengthening, government's political support for distribution facility, transportation route, load and unloading works' improvement, price competitiveness' securing, professional manpower's cultivation by education and training, etc. Here are some suggestions for foreign produce importation. First, the government should conduct a survey on the current distribution channels and analyze the situation to establish a measure for long-term development plans. By providing each agricultural area with a guideline for planning appropriate production of crops, the government can help farmers be ready for importation, and prevent them from producing same crops all at the same time. Government can sign an MOU with the foreign government and promote the importation so that the development of agricultural resources can be stable and steady. Second, the government can establish a strategy for an effective distribution system by providing farmers and agriculture-related workers with the distribution information such as price, production, demand, market structure and location, feature of each crop, and etc. In order for such distribution system to become feasible, the government needs to reconstruct the current distribution system, designate a public organization for providing distribution information and set the criteria for level of produce quality, trade units, and package units. Third, the government should provide financial support and a policy to seek an efficient distribution channel for foreign produce to be delivered fresh: the government should expand distribution facilities (for selecting, packaging, storing, and processing) and transportation vehicles while modernizing old facilities. There should be another policy to improve the efficiency of unloading, and to lower the cost of distribution. Fourth, it is necessary to enact a new law covering exceptional cases for importing produce in order to maintain the price competitiveness; currently the high tariffs is keeping the imported produce from being distributed domestically. However, the new adjustment should be made carefully within the WTO regulations since it can create a problem from giving preferential tariffs. The government can also simplify the distribution channels in order to reduce the cost in the distribution process. Fifth, the government should educate distributors to raise the efficiency and to modernize the distribution system. It is necessary to develop human resources by educating people regarding the foreign agricultural environment, the produce quality, management skills, and by introducing some successful cases in advanced countries.

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Design of Push Agent Model Using Dual Cache for Increasing Hit-Ratio of Data Search (데이터 검색의 적중률 향상을 위한 이중 캐시의 푸시 에이전트 모델 설계)

  • Kim Kwang-jong;Ko Hyun;Kim Young-ja;Lee Yon-sik
    • Journal of the Korea Society of Computer and Information
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    • v.10 no.6 s.38
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    • pp.153-166
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    • 2005
  • Existing single cache structure has shown difference of hit-ratio according to individually replacement strategy However. It needs new improved cache structure for reducing network traffic and providing advanced hit-ratio. Therefore, this Paper design push agent model using dual cache for increasing hit-ratio by reducing server overload and network traffic by repetition request of persistent and identical information. In this model proposes dual cache structure to do achievement replace gradual cache using by two caches storage space for reducing server overload and network traffic. Also, we show new cache replace techniques and algorithms which executes data update and delete based on replace strategy of Log(Size) +LRU, LFU and PLC for effectiveness of data search in cache. And through an experiment, it evaluates Performance of dual cache push agent model.

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A Study on Yard Operation in Container Terminal (컨테이너 터미널에서의 장치장 운용 계획에 관한 연구)

  • Kim Kap-Hwan;Kim Jae-Joong;Ryu Kwang-Ryel;Park Nam-Kyu;Choi Hyung-Rim;Jeon Su-Min
    • Journal of Intelligence and Information Systems
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    • v.12 no.1
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    • pp.125-137
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    • 2006
  • One of the important tactical problems for the efficient operation of container terminals is to determine the usage of storage space There are two different strategies for stacking containers; mixing strategy, in which outbound containers and inbound containers are mixed in the same block, and segregating strategy, in which outbound containers and inbound containers are stacked in blocks different from each other The performance of space allocation strategies also depends on the types of handling equipment in the yard and the number of handling equipment allocated to each block. A simulation model is developed considering various handling characteristics of yard cranes. Performances of various space and equipment allocation strategies are evaluated by using the simulation model.

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A Study of Direct and Contingency Factors Affecting Customer Switching Intension of E-mail Services in Portal Sites (포털사이트에서 이메일 서비스의 전환의도에 영향를 미치는 직접적 요인과 상황적 요인에 관한 연구)

  • Kim, Gi-Mun;Lee, Jung-Woo;Nam, Sang-Min;Lee, Ho-Geun
    • Information Systems Review
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    • v.7 no.1
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    • pp.115-136
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    • 2005
  • Recently Internet portals contend with each other to expand their customer base by providing customers with a much amount of e-mail storage. But This strategy may not be successful because of customers' switching cost following site moving. Therefore, in order to reveal whether their strategy makes sense, this study investigates the direct and contingency factors affecting customer switching intension of e-mail services in portal sites. The research results show that attractiveness of alternatives, switching cost, and customer satisfaction have a significantly direct impact on customer switching intension of e-mail services. Also, attractiveness of alternatives alone has an moderated effect on customer switching intension but switching cost does not. Thus, Internet portals may reap the harvest from their recent aggressive action.

Improved instantaneous Following Control Function for High Power Factor PWM Matrix Converter (고역율 PWM 매트릭스 컨버터의 개선된 순시추종 제어함수)

  • Kim, Kwang-Tae
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.19 no.3
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    • pp.35-43
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    • 2005
  • Matrix converters have been studied for eliminating dc link of conventional converter-inverter system, and various undulation strategy have been proposed. Therefore, matrix converter have no energy storage component except for small ac later for the elimination of switching ripple, and can be made compact and highly reliable compare with the do link inverter system. Matrix converter, however, directly connected the input and the output terminals by bidirectional static switch. As a result if the input voltage are asymmetrical, and contain harmonics, the influence of the distortions directly appear on the output terminal. This problem is a major obstacle to the matrix converter. A new control method using average comparison strategy have been proposed in this paper. This control method realizes sinusoidal input and output current unity input displacement factor regardless of load power factor. Moreover, compensation of the asymmetrical and/or harmonic containing input voltage is automatically realized, and calculation time of control function is reduced.

A review of smart exsolution catalysts for the application of gas phase reactions (기상 반응용 스마트 용출 촉매 연구 동향)

  • Huang, Rui;Kim, Hyung Jun;Han, Jeong Woo
    • Ceramist
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    • v.23 no.2
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    • pp.211-230
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    • 2020
  • Perovskite-type oxides with the nominal composition of ABO3 can exsolve the B-site transition metal upon the controlled reduction. In this exsolution process, the transition metal emerges from the oxide lattice and migrates to the surface at which it forms catalytically active nanoparticles. The exsolved nanoparticles can recover back to the bulk lattice under oxidation treatment. This unique regeneration character by the redox treatment provides uniformly dispersed noble metal nanoparticles. Therefore, the conventional problem of traditional impregnated metal/support, i.e., sintering during reaction, can be effectively avoided by using the exsolution phenomenon. In this regard, the catalysts using the exsolution strategy have been well studied for a wide range of applications in energy conversion and storage devices such as solid oxide fuel cells and electrolysis cells (SOFCs and SOECs) because of its high thermal and chemical stability. On the other hand, although this exsolution strategy can also be applied to gas phase reaction catalysts, it has seldomly been reviewed. Here, we thus review recent applications of the exsolution catalysts to the gas phase reactions from the aspects of experimental measurements, where various functions of the exsolved particles were utilized. We also review non-perovskite type metal oxides that might have exolution phenomenon to provide more possibilities to develop higher efficient catalysts.

Selection Strategy for the File Format of Official Documents in a Cloud Environment (클라우드 환경에서 공문서 파일포맷의 선택 전략)

  • Yim, Jin Hee
    • The Korean Journal of Archival Studies
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    • no.66
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    • pp.5-35
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    • 2020
  • In the digital age, the most basic unit of records management is a document file. Depending on whether each document file is produced in an open standard format or an exclusive proprietary format, there is a cost difference in the process of use and long-term preservation. As government agencies moved to cloud-based business management systems, web-based document editing software was newly adopted. They had the opportunity to select a new file format for web-based document editing software. This paper deals with strategies to maximize the advantages of open standard formats while considering the legacy public document production practices. It introduces ISO/IEC 26300:2006 ODF, ISO/IEC 29500:2008 OOXML, KS X 6101 OWPML, etc. as open standard formats, and looks at considerations when choosing a format and web-based document editing software. In addition, it proposes a strategy to maintain the format of document files shared in cloud storage as an open standard format.

The Status of the Sericulture Industry and the Development Strategy (양잠산물 생산·판매 구조와 산업분야별 개선과제)

  • Kim, Kyung-Phil;Kwon, Tae-Jin
    • Journal of agriculture & life science
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    • v.45 no.2
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    • pp.135-145
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    • 2011
  • Recently, silk farming trends are changed from silk production to functional production because of a slump in only silk production. The 'Functional silk farming production promotion and assistant ACT', which has been enacted and effective since 2009, provides an environment to create the integrated functional sericulture production program. The purpose of this study is to derive the current industry status and the development strategy resulting in promoting and creating a new value-added industry. The main items to be improved in current sericulture industry are production infra and facilities, post-harvest storage technology, processing and marketing, sericulture farming products trading, exporting and merchandised promoting, farm management and farm income etc. Future sericulture industry should be focus on Mulberry production and Processing instead of silk farming only for a new valued added industry.