• Title/Summary/Keyword: Control of demand and supply

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Development of an Algorithm for Minimization of Passengers' Waiting Time Using Smart Card Data (교통카드 데이터를 이용한 버스 승객 대기시간 최소화 알고리즘 개발)

  • Jeon, Sangwoo;Lee, Jeongwoo;Jun, Chulmin
    • Spatial Information Research
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    • v.22 no.5
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    • pp.65-75
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    • 2014
  • Bus headway plays an important role not only in determining the passenger waiting time and bus service quality, but also in influencing the bus operation cost and passenger demand. Previous research on headway control has considered only an hourly difference in the distribution of ridership between peak and non-peak hours. However, this approach is too simple to help manage ridership demand fluctuations in a short time scale; thus passengers' waiting cost will be generated when ridership demand exceeds the supply of bus services. Moreover, bus ridership demand varies by station location and traffic situation. To address this concern, we propose a headway control algorithm for minimizing the waiting time cost by using Smart Card data. We also provide proof of the convergence of the algorithm to the desired headway allocation using a set of preconditions of political waiting time guarantees and available fleet constraints. For model verification, the data from the No. 143 bus line in Seoul were used. The results show that the total savings in cost totaled approximately 600,000 won per day when we apply the time-value cost of waiting time. Thus, we can expect that cost savings will be more pronounced when the algorithm is applied to larger systems.

Application of Linear Tracking to the Multi-reservours System Operation in Han River for Hydro-power Maximization (한강수계 복합 저수지 시스템의 최적 수력발전 운영을 위한 LINEAR TRACKING의 적용)

  • Yu, Ju-Hwan;Kim, Jae-Han;Jeong, Gwan-Su
    • Journal of Korea Water Resources Association
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    • v.32 no.5
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    • pp.579-591
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    • 1999
  • The operation of a reservoir system is necessary for establishing the operation rule as well as designing the reservoirs for water resources planning or management. Increasingly complex water resource systems require more advanced operation techniques. As a result, various techniques have been introduced and applied until now. In this study Linear Tracking model based on optimal control theory is applied to the operation of the largest scale multi-reservoir system in the Han river and its applicability proved. This system normally supplies the water resources required downstream for hydro-power and plays a role in satisfying the water demand of the Capital region. For the optimal use of the water resources the Linear Tracking model is designed with the objective to maximize the hydro-power energy subject to the water supply demand. The multi-reservoir system includes the seven main reservoirs in IIan river such as Hwachon, Soyanggang, Chunchon, Uiam, Cheongpyong, Chungju and Paldang. These reservoirs have been monthly operated for the past 21 years. Operation results are analyzed with respect to both hydro"power energy and water supply. Additionally the efficiency of the technique is assessed.sessed.

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Doors open and close during regenerative energy harvester developed (자동문 개폐 시 회생에너지 하베스트 개발)

  • Park, Won-hyeon;Kim, Min;Jeong, Jae-hoon;Lee, Dong-heon;Byun, Gi-sik;Kim, Gwan-hyung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.10a
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    • pp.257-258
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    • 2015
  • Korean power consumption of the electrical supply problems due to excess demand is repeated every year, the interest in energy increasing social and personal cost has been subject to the number of ways to reduce this cost increases. Automatic doors and automatic door installation market is increasing every year and frequently, when used in general commercial and communal porch consumption based on average 300 times a day power is 70[W] degree is a monthly average usage is about 50.4[KW]. The level can not ignore the power consumption due to switching frequency is large. In this paper, by converting the energy to be discarded in the automatic doors to the inverter and the regenerative energy and to develop control systems for power regeneration to reduce the power consumption by utilizing automatic contact auxiliary power.

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Challenges of Korean organic rice farming - practices, economic performances and implications from the case study of Jeonnam province

  • Seo, Gwi-Soo;Lee, Jin-Woo;Nicholas, Phillipa;Cho, Youn-Sup
    • Proceedings of the Korean Society of Organic Agriculture Conference
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    • 2009.12a
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    • pp.284-284
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    • 2009
  • EFA production systems have through necessity resulted in the development of innovative practices for weed, pest and diseases control, for example, using ducks and snails for weed control in paddy fields. These practices began to be introduced in the early 1990's and the techniques have become more popular and have been adapted to suit regional conditions. In this study, the production practices, productivity and economic performances of organic and non-chemical rice farming adopting ducks and snails for weed control were compared. In the production practices, Korean organic and non-chemical farming seem to have several concerns in terms of sustainability. It comprises lack of resistant variety use and rotational cropping system as well as high dependency upon external inputs such as organic fertilizer and farming materials for pest control. The production level of organic farming is approximately similar level but 20% higher income than non-chemical farming, while, when it was compared with conventional farming organic farming showed 20% lower productivity but 20% higher income. Organic farming shows 15% to 18% higher profits than non-chemical farming as the snail-using organic farming tends to have higher income and lower input costs than duck-using organic farming. This may encourage more farmers to convert to organic production using these techniques than simply non-chemical farming in the future. This organic conversion could be more promoted by policy intervention. However, it may result in increased supply and therefore decreased prices for organic rice in the long term unless further market demand occurs. Balanced policy measures considering production as well as marketing and consumption are urgently required for the sustainable development of organic farming.

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Experimental Test Results of Nine Scheduling Operational Modes of PV and Battery Hybrid System for the Development of Automatic Control Algorithm for Continual Operation without being shut-downed (태양광 배터리 Hybrid 전력공급시스템 9가지 운전 모드 시험결과 및 무고장 연속 운전을 위한 자동제어 알고리즘 개발)

  • Song, Taek Ho;Yang, Seung Kwon;Kim, Minjeong
    • KEPCO Journal on Electric Power and Energy
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    • v.5 no.1
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    • pp.25-32
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    • 2019
  • K-BEMS System was introduced to reduce peak load and to save total energy of the 200 buildings that KEPCO headquarter and branch offices use. And K-BEMS system is composed of PV, battery, and hybrid PCS. KEPCO research institute has carried out this K-BEMS research project for 3 years since January 2016. In this paper, the results of the project are shown. 9 modes of test results of K-BEMS system and are operational problems were analyzed. And measures to cure the trouble are also suggested. Batteries are operated more than 20% of SOC, and less than 20% of SOC battery protection switches are automatically shutting down the system and the system no longer respond to EMS, ending the supply of PV, and so therefore to continue the PV power supply it was turn out to be necessary that the EMS should automatically change its policy to change PV only supply mode automatically when the Battery Switch automatically operated. To operate the system continuously and automatically, it is necessary to modify the minimum operational SOC value, and in addition to that the EMS computer must remember the last shut-down SOC and Voltage which interrupted the system and add some margin to reflect the measurement error in the system.

A Study on CNN based Production Yield Prediction Algorithm for Increasing Process Efficiency of Biogas Plant

  • Shin, Jaekwon;Kim, Jintae;Lee, Beomhee;Lee, Junghoon;Lee, Jisung;Jeong, Seongyeob;Chang, Soonwoong
    • International journal of advanced smart convergence
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    • v.7 no.1
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    • pp.42-47
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    • 2018
  • Recently, as the demand for limited resources continues to rise and problems of resource depletion rise worldwide, the importance of renewable energy is gradually increasing. In order to solve these problems, various methods such as energy conservation and alternative energy development have been suggested, and biogas, which can utilize the gas produced from biomass as fuel, is also receiving attention as the next generation of innovative renewable energy. New and renewable energy using biogas is an energy production method that is expected to be possible in large scale because it can supply energy with high efficiency in compliance with energy supply method of recycling conventional resources. In order to more efficiently produce and manage these biogas, a biogas plant has emerged. In recent years, a large number of biogas plants have been installed and operated in various locations. Organic wastes corresponding to biogas production resources in a biogas plant exist in a wide variety of types, and each of the incoming raw materials is processed in different processes. Because such a process is required, the case where the biogas plant process is inefficiently operated is continuously occurring, and the economic cost consumed for the operation of the biogas production relative to the generated biogas production is further increased. In order to solve such problems, various attempts such as process analysis and feedback based on the feedstock have been continued but it is a passive method and very limited to operate a medium/large scale biogas plant. In this paper, we propose "CNN-based production yield prediction algorithm for increasing process efficiency of biogas plant" for efficient operation of biogas plant process. Based on CNN-based production yield forecasting, which is one of the deep-leaning technologies, it enables mechanical analysis of the process operation process and provides a solution for optimal process operation due to process-related accumulated data analyzed by the automated process.

A Study on Problems and Improvement of Government's Real Estate Policy (정부의 부동산 정책 문제점과 개선방안)

  • Kim, Taek
    • The Journal of the Convergence on Culture Technology
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    • v.7 no.1
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    • pp.256-263
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    • 2021
  • This paper studies the problems and improvements of government real estate policies. Moon Jae-in government shifted toward regulation and pledge to curb the tax imposed by speculators. It strengthened regulations on reconstruction and bank loans rather than supply, and raised capital gains taxes. As the government implemented measures, emphasizing political logic rather than the economy, the market is unstable and the economy is in a recession. Land has increased the vicious cycle of problems due to population growth, industrialization, urbanization, and wealth growth. Mis-established land policies not only accelerate land prices, but also accelerate the use of disordered land and lead to disruptions in the trading order. In addition, real estate is so difficult to recover from the land problem that it is difficult to contain water that has been spilled once. This is called the irreversible nature of land. Once the land price rises, it is difficult to regain control and reckless development leads to the destruction of the ecosystem, making it difficult to return. This is why such a complex real estate issue should not be implemented as if it were a punishment in a short period of time with government policies. This paper aims to examine the problems of real estate policies and to examine ways to improve them.

Development of Intelligent Switchgear Monitoring System based on Smartphone (스마트폰 기반의 지능형 수배전반 모니터링 시스템 구현)

  • Jung, Hae-Kyung;Jeon, Gam-Pyo;Jeong, Do-Un
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2012.05a
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    • pp.378-379
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    • 2012
  • Nowadays, great energy consumption in advanced electrical industry has called up the great y efficiency. Electric power IT industry such as intelligent electric power system is receiving great attention and being marked up as a new growth engine. Through Intelligent electric power system, the electric power supply can be balance optimized according to demand, giving huge cost savings advantage for energy imports, infrastructure construction and operation. Nevertheless, the intelligent system promotes better reliability in power supply. Manual electric power management using man power appears to be non-practical. Real time electric power management on all facilities and equipment can be done through an intelligent electric power system, any accident break out issue can be easily recorded and recognized. In this paper, a fully integrated intelligent switchgear electric management system is developed to monitor and remote control the electrical switch based on smart phone. The proposed system is superior than the existing switchgear management system's weakness and can sharply improve effectiveness and stability with low cost. In future, the proposed system is expected to be greatly contributed to the advancement of the IT industry in electric power management.

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Research Trends and Future Directions for R&D Vitalization of Domestic Dairy Industry (국내 유가공산업의 R&D활성화를 위한 연구 동향과 방향)

  • Yoon, Sung-Sik
    • Journal of Dairy Science and Biotechnology
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    • v.29 no.1
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    • pp.23-31
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    • 2011
  • Domestic dairy industry is now standing at the crossroad for planning next fifty years, mainly because economic and environmental situations surrounding Korean peninsula are fast changing. For the aspects of dairy consumption, fresh milk consumed less, while consumption of the other milk and dairy products is slightly increasing every year. In 2010, it is approximately estimated that 1,939,000 tons of raw milk was used and the supply would be short by about 35,000 tons, based on the amounts in the previous year. Currently, multilateral negotiations against US and EU are underway. When it will be in effect in the future, significant damage would be expected in the dairy and livestock sectors, leading to cut domestic milk supply. Quality of farm-gate milk is graded as 1A on average 90% or more, loaded with very low in microbial and somatic cell counts. Therefore, policy implications have to be placed toward switch currently the UHT processing method to Pasteurization or the LTLT technology, by which natural flavors and nutrients in milk mostly remain after heat treatment. Domestic cheese products comprise only 10% and the rest is occupied by the various kinds of imported natural products. The market size keeps increasing up to 65,423,000 tons last year. When it comes to vitalization of our natural cheese industry, cheese whey, which is a main by-product in cheese manufacture, is a critical issue to be solved and also "On-Farm Processing" would be combined with a growth of big dairy companies when few immediate issues among the relevant regulations will be eased and alleviated in the near future. Fermented milk market is recorded as a single area of gradual increase in the past 10 years, Korea. Fermented yogurts with health claims targeted stomach, liver, and intestine are popular and has grown fast in sales amounts. In this context, researches on beneficial probiotic lactic acid bacteria are one of the important projects for domestic milk and dairy industries. Labelling regulations on efficacy or health-promoting effects of functional dairy products, which is the most important issue facing domestic dairy processors, should be urgently examined toward commercial expression of the functionality by lawful means. Colostrum, a nutrition-rich yellowish fluid, is roaded with immune, growth and tissue repair factors. Bovine colostrum, a raw material for immune milk preparations and infant formula, can be used to treat or prevent infections of the gastrointestinal tract. Nanotechnology can be applied to develop new milk and dairy products such as micro-encapsulated lactase milk for consumers suffering lactose intolerance. Raw milk is suggested to be managed by its usage in the processing line because imbalance of supply and demand is structural problem in every country and thus the usage systems as in the advanced dairy countries is worth of bench-marking to stabilize milk supply and demand. Raw milk produced is desirable to divide into the three parts; domestic, import, and buffering purposes. It is strongly recommended that a domestic dairy control center as an institutional framework should be urgently established as is Dairy Board in New Zealand and Australia. Lastly, government policy should be directed to foster the highly-educated people who are majoring in Dairy Sciences or working in the dairy industry by means of financial support in studying and training abroad as well.

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The study of the relationship of the defense industry-specific factors effect the innovation of manufacturing technology and the market share. (방위산업의 시장구조 결정요인이 기술혁신과 시장지배에 미치는 영향)

  • Chung, Young-Hyun
    • Journal of National Security and Military Science
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    • s.5
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    • pp.241-280
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    • 2007
  • This study examines the relationship of the industry-specific factors that effect innovation of manufacturing technology and the market share within the defense industry. Since the establishment of the basic defense industry framework in 1973, there were numerous interactions of the industry-specific factors of the defense industry structure with the technological innovation and market organization of the defense industry. During last three decades, the domestic defense industry has achieved the considerable level but the framework of the basic system has not developed much in areas of the military science and the defense manufacturing technology. Industry-specific factors were formed in the process and appeared in a variety of behavioral characteristics as subsystems. Currently, there IS a growing trend where the management of defense industry is gradually deteriorating due to limitation of the domestic industry-specific factor (e.g. defense technologies, amount of demand, etc.). If there is a prominent imbalance of the industry-specific factors. it can trigger the potential problem of conflict, lack of cooperation and control, slowing the growth of the manufacturing technology thereby diminishing the market and deteriorating the defense supply/demand relationship. In a research conducted by Joe S. Bain, Bain analyzed the relationship of the traditional industrial organization where industry-specific factor(S) not only impacts the conductor(C). And, conductor(C) influences the shaping of the performance(P) of relationship of the traditional industrial organization. Consequently, the researcher has identified the demand monopoly, barriers to entry, and market competition with comparison of defense industry issues. These defense issues were three industry-specific factors identified, which are 1) The demand monopoly and The entry barriers to new market competition, 2) the industrial technical factor to a production technical competitiveness and a market sharing competitiveness, 3) the probability factor to revolution for military affairs(RMA) and a R&D production. According to baseline with these factors, the following research model is established from the special companies group(Group A), the systematization companies group(Group B), and the general companies group(Group 0. The hypothesis is that if there are more industry-specific factors, then there will be more relationships of defense industry relation statutes. This research is an empirical study on the relationship that the industry specific factors effects the innovation of manufacturing technology and the shaping of the market in the defense industry. Moreover, the existing models to evaluate the industry specific factors of the defense industry IS much to be desired with the controlled statistical analysis of the result. It is vital to study on current situation with suggesting alternative strategy to the efficient strategy. The descriptive analysis approach analysis is conducted with SPSSWIN to conduct reliability test, factor analysis, correlation analysis, cross-tabulation analysis, one-way ANOVA, and multiple regression analysis. However, there were some limitations of the survey such as the rigidity of concept about the technical factors and various market management factors. The wishes is that the decision-maker could be utilized these defence industrial factors to formulate efficient defence policy and strategy in the future.

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