• Title/Summary/Keyword: need and demand

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Optimal Operating Method of PV+ Storage System Using the Peak-Shaving in Micro-Grid System (Micro-Grid 시스템에서 Peak-Shaving을 이용한 PV+ 시스템의 최적 운영 방법)

  • Lee, Gi-hwan;Lee, Kang-won
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.43 no.2
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    • pp.1-13
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    • 2020
  • There are several methods of peak-shaving, which reduces grid power demand, electricity bought from electricity utility, through lowering "demand spike" during On-Peak period. An optimization method using linear programming is proposed, which can be used to perform peak-shaving of grid power demand for grid-connected PV+ system. Proposed peak shaving method is based on the forecast data for electricity load and photovoltaic power generation. Results from proposed method are compared with those from On-Off and Real Time methods which do not need forecast data. The results also compared to those from ideal case, an optimization method which use measured data for forecast data, that is, error-free forecast data. To see the effects of forecast error 36 error scenarios are developed, which consider error types of forecast, nMAE (normalizes Mean Absolute Error) for photovoltaic power forecast and MAPE (Mean Absolute Percentage Error) for load demand forecast. And the effects of forecast error are investigated including critical error scenarios which provide worse results compared to those of other scenarios. It is shown that proposed peak shaving method are much better than On-Off and Real Time methods under almost all the scenario of forecast error. And it is also shown that the results from our method are not so bad compared to the ideal case using error-free forecast.

An Empirical Analysis on Citizens' Awareness of an Intangible Cultural Heritage (무형문화유산 활성화를 위한 수요자 인식에 관한 실증적 분석)

  • Oh, Jung-Shim
    • The Journal of the Korea Contents Association
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    • v.15 no.9
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    • pp.29-36
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    • 2015
  • This study aims to examine the problems that transmissions of an intangible cultural heritage in Korea may be cut off because of the public indifference, low demand for it and lack of government funding and seek ways to revitalize an intangible cultural heritage by increasing citizens' awareness of it and demand for it. According to recent studies, many holders of important intangible cultural properties have a difficulty doing because government funding is not enough to make their living and people who want to learn and pass on traditional skills keep decreasing. Many experts say that governments need to increase citizens' awareness of an intangible cultural heritage and demand for it in the long run to solve this problem, but governments focus on improving condition of holders rather than that. On this account, this study criticizes the government's policy and surveys citizens' awareness of an intangible cultural heritage and demand for it and suggests a plan of revitalizing an intangible cultural heritage.

RPSMDSM: Residential Power Scheduling and Modelling for Demand Side Management

  • Ahmed, Sheeraz;Raza, Ali;Shafique, Shahryar;Ahmad, Mukhtar;Khan, Muhammad Yousaf Ali;Nawaz, Asif;Tariq, Rohi
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.6
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    • pp.2398-2421
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    • 2020
  • In third world countries like Pakistan, the production of electricity has been quickly reduced in past years due to rely on the fossil fuel. According to a survey conducted in 2017, the overall electrical energy capacity was 22,797MW, since the electrical grids have gone too old, therefore the efficiency of grids, goes down to nearly 17000MW. Significant addition of fossil fuel, hydro and nuclear is 64.2%, 29% and 5.8% respectively in the total electricity production in Pakistan. In 2018, the demand crossed 20,223MW, compared to peak generation of 15,400 to 15,700MW as by the Ministry of Water and Power. Country faces a deficit of almost 4000MW to 5000MW for the duration of 2019 hot summer term. Focus on one aspect considering Demand Side Management (DSM) cannot oversea the reduction of gap between power demand and customer supply, which eventually leads to the issue of load shedding. Hence, a scheduling scheme is proposed in this paper called RPSMDSM that is based on selection of those appliances that need to be only Turned-On, on priority during peak hours consuming minimum energy. The Home Energy Management (HEM) system is integrated between consumer and utility and bidirectional flow is presented in the scheme. During peak hours of electricity, the RPSMDSM is capable to persuade less power consumption and accomplish productivity in load management. Simulations show that RPSMDSM scheme helps in scheduling the electricity loads from peak price to off-peak price hours. As a result, minimization in electricity cost as well as (Peak-to-Average Ratio) PAR are accomplished with sensible waiting time.

Long-run Estimation of Fertilizer Demand in Korea to Meet the National Food Supply (식량수급(食糧需給)에 따른 비료수요(肥料需要) 전망(展望))

  • Lee, Yun-Hwan
    • Korean Journal of Soil Science and Fertilizer
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    • v.9 no.3
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    • pp.133-147
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    • 1976
  • 1. The purpose of this study is to provide a series of statistical "bench marks" from which one can begin to think systematically about the required development of the Korean food and fertilizer needs over the next quarter-century. 2. The Korean population has been estimated by the characteristics of the population and its social and political situations today. Because fertility and mortality rates are relatively stable and are under control of politics concerned, the estimation rates were established with 1.6% over 1975-1980, 1.3% over 1981-1990, and 1.0% over 1991-2000. 3. Annual per capita absorption of milled rice has fluctuated rather closely around 140kg, since 1968, with no evidence of declining trend. Per capita absorption of barley and wheat around 120 kg, and legumes around 10.6kg, However because the case of wheat and corn productions are rather difficult the self-sufficiency in the future, the rice is considered to be accelerate its yield growth surplus the level of self-sufficiency to export. 4. The fertilizer demand in each element has been calculated by mechanical multiplication of "the recommend index of fetilizer application" to yield a unit production over the need of national food supply by crop year. 5. As a results refer to Table (8), the estimated quantities of total fertilizer demand to meet the national food supply of the years of 1974, 1980, 1985, 1.990, 1995, and 2000 are reached around 871500, 1138150, 1375480, 1515030, 1652090 and 1799850 metric tons in each year.

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Biofuel Industry and Recent Research in USA (미국의 바이오연료와 연구 동향)

  • Lee, Joung-Kyong;Bransby, David
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.28 no.2
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    • pp.129-138
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    • 2008
  • Demand for alternatives to petroleum is increasing the production of biofuels from food crops such as corn, soybeans, sorghum and sugarcane, etc. At least for the next 5 years, ethanol demand will be increased greatly in the United States and in the world. Presently, most ethanol produced in the United States is corn (Zea mays) ethanol. As a result, especially in the Americas and Southeast Asia, agricultural land is diverted to biofuel production. Even though biofuel industry has many advantage including national security, economical, energetical and sustainable impacts, it is driving grain prices up and creating considerable concern about the potential negative impacts on a wide range of food products that depend on gain : chicken, pork, beef, and dairy products such as milk, cheese, yoghurt, cream and ice cream. Feedstock crops are crops such as switchgrass(Panicum virgatum, L.), corn stover and grasses that can be used in industrial processes such as fermentation into alcohol fuels. Feedstock is no compete with food. Furthermore it is friendly environmental bioenergy crops. In Korea, with increasing demand for fossil fuels the exploration of alternative sources of liquid fuel is inevitable. I suggest Korea need to research and to develop actively on feedstock for biofuel production through this review.

The Research on Activation Plan for Seawater Desalination Plant Application in Korea (국내 해수담수화 플랜트 적용 활성화 방안 연구)

  • Sohn, Jinsik;Yang, Jeong-Seok;Park, Jinseo
    • Journal of Korean Society of Water and Wastewater
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    • v.23 no.2
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    • pp.251-255
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    • 2009
  • Foreign and domestic seawater desalination plant market investigation was performed to analyze the worldwide trend of seawater desalination plant market and to establish the activation plan for seawater desalination plant application. Water demand and seawater desalination related laws and regulations were investigated and analyzed for the activation plan. RO type and large scale plants are popular nowadays however there are only small plants in island region in Korea. There will be about $1 million\;m^3/day$ deficit in 2015 according to the water demand forecasting from Ministry of Environment and Ministry of Land, Transportation, and Maritime Affairs in Korea. Therefore, it is necessary to activate the domestic application of seawater desalination plant to secure stable water resources. To activate the domestic application of seawater desalination plant, first, we need to establish regulations, support system in the water service law for seawater desalination plant. Second, related Ministry should increase the support for the operation and management of seawater desalination plant and suggest the construction of seawater desalination plant for water resources security near seaside region.

인터넷을 이용한 글로벌 제조환경의 구축

  • 김태운;김홍배;현재명
    • Proceedings of the Korea Association of Information Systems Conference
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    • 1997.10a
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    • pp.113-125
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    • 1997
  • The objective of this research is to construct and build a software platform to enable collaboration among enterprise headquarters, product designers, software engineers, manufacturing plants, and suppliers which are located at different remote locations via internet. In specific, agent technology is adopted as a software vehicle to automate demand as a software vehicle to automate demand and supply process in the internet environment. Agents are programs that act an behalf of their human users to perform laborious tasks such as information locating, accessing, filtering, integrating, adapting and resolving inconsistencies. Global competition is forcing the present day industry to produce high quality product more fast and inexpensively. In Korea, most labor-intensive industries have moved to China and other Asian countries for cost reduction. The need for fast information exchange has increased among the remote locations for the cooperation and coordination. In this research, a virtual global manufacturing system will be constructed that distributes production schedule among remote places, acts as a bridge between the headquarters and manufacturing plants, distributes tasks and collates different solutions between demand and supply using agent. The external communication protocol takes HTML format, internal message handling requires SGML for document exchange, and KQML for agent implementation. The expected benefits will be : reduced cost of real-time information exchange, realization of global manufacturing environment, the maximum utilization of internet for the enterprise data exchange.

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Shell platings manufacturing M/H inference and comparison using Artificial Neural Network and Gentic Programming (인공신경망과 유전적 프로그래밍을 이용한 선체 곡가공 M/H 추론 및 비교)

  • Shin, Yong-Wook;Ha, Duk-Ki;Jo, Moon-Hee;Kim, Su-Young
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2003.10a
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    • pp.163-166
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    • 2003
  • Hull form designers have to design a ship with satisfying an economical, technical and environmental demand. When it is concerned by a technical and environmental demand, there will be a economical demand left to criticize optimization. In this case, there were used to be requirements which needs to meet only a best performance not concerning about input of Human resource. Life cycle's cost contains building cost and operation cost so that now we need to check Man Hour cost in building a ship. This research shows a correlation between hull form information, i.e. curvature, length, breadth and thickness of surface and Man Hour of the Shell plating manufacture with using Artificial Neural Network and Gentic Programming. This study will support to classify initial work, to have a high assumption possible through predicting a Man Hour and to provide a guide book to infer a building cost and a economical optimization hull form.

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A Study of Spousal Support, the Demand for Health Education, and Quality of Life for Married Female Immigrants (국제결혼 이주여성의 배우자 지지, 건강교육 요구와 삶의 질)

  • Kim, Hye-Ja
    • Women's Health Nursing
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    • v.14 no.1
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    • pp.5-11
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    • 2008
  • Purpose: The purpose of this study was to understand spousal support, demand for health education, and quality of life for married female immigrants. Methods: A total of 120 subjects with adequate communication skills participated in this study from March 1, 2006 until January 30, 2007. Participants were female visitors at the Immigrant Consultation Center in "M City", "Y County" and "M County" in South Jeolla Province. The questionnaire used in this study consisted of a total of 42 items. Data were analyzed using SPSS/win 10.2 to describe subjects' characteristics by frequency, and descriptive statistics, and to test group differences by t-test and ANOVA. Results: The highest demand for health education was exercise, and followed by stress management and diet. The level of spousal support for subjects was below average, and the level of quality of life was above the medium. The most difficult thing in their life was the difficulty in language. There was a significant difference in quality of life by level of education, level of life satisfaction, number of childbirths, and age. There was also a significant difference in spousal support by level of life satisfaction. Conclusion: There is a need for a multidimensional strategy to improve the quality of life and spousal support for immigrant females in international marriages.

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A Study on the Requirements and Compliance Standard of a Presentation for Demand for Payment under URDG (URDG 하의 지급청구를 위한 제시요건과 그 일치성 기준)

  • Chae, Jin-Ik
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.50
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    • pp.109-136
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    • 2011
  • Bank Guarantee system is commonly used as useful financial instruments to support various overseas and domestic business activities by providing bank guarantees. Therefore, it will be able to develop as a useful socio-economic useful system. However, some procedural problem can arise from the processes under demands for payment. Therefore, it is very important to review the requirements of the demand for payment and compliance standard for the examination of a presentation under the guarantee system. It is necessary to examine main issues under the revised URDG 758. The URDG introduced the same examination principle of "need not be identical to, but shall not conflict with' as that of UCP 600. The main changes of the URDG 758 like this imply the mitigation of the compliance standard for examination. So, This paper is to provide a comparative study of the regulations and laws for the examination standard and propose their implications and practical notes under bank guarantee system. For this purpose, this study will be examined the practical and legal issues focusing on the relative regulations of the revision URDG 758. It will also be reviewed and compared with the URDG, ISP98, UCP 600 and so on.

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