• Journal of the Korean Physical Society
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• v.73 no.10
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• pp.1431-1436
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• 2018

We study the scaling of the price fluctuation in the Korean housing market. From the numerical analysis, we show that the normalized return distribution of the housing price, P(r), has a fat-tail and is well approximated by a power-law, $P(r){\sim}r^{-({\alpha}+1)}$, with ${\alpha}{\simeq}3$ for the whole data set. However, if we divide the data into groups based on the trading patterns, then the value of ${\alpha}$ for positive tail and negative tail can be different depending on the trading patterns. We also find that the autocorrelation function of the housing price decays much slower than that of the stock exchange markets, which shows a unique feature of the housing market distinguished from the other financial systems.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.6
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• pp.9-20
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• 2015

The demand of renewable energy is expected to grow in the long run in spite of current stable lower oil prices. Energy consumption for heating in horticulture greenhouse is large and affects the profits of the farms. This study analyzed the availability of biomass in rural area and proposed the strategies for utilizing the biomass for greenhouse heating. Data reveal the annual average fuel consumption in greenhouses is about 78 TOE/ha. Considering biomass resource in rural areas, agricultural residues are not sufficient to meet the biomass demand from greenhouses. Therefore it is recommended to secure further biomass including wild herbaceous biomass and woody biomass from forest. Based on the conditions of biomass gasification equipment investment and fuel prices, maximum allowable price of biomass turned out about 100,000 KRW/t to be competitive to kerosine. Biomass supply chain should be established for facilitating biomass trading between biomass consumers and biomass producers such as farmers who provide crop residues. An online trading system is an example of the system where consumers who utilize biomass make payments to suppliers and get the information about the biomass. Intermediate collection storages are required to store biomass from distributed sources. Operation of biomass heating systems in demonstration greenhouses is necessary to get information to refine and further develop commercial biomass heating systems. Relatively large greenhouses are desirable to have biomass heating systems for economic viability. The location of the greenhouse farms should be selected within the area where enough biomass resources are available for feeding the biomass facility.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.2
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• pp.230-236
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• 2011

This paper proposes the possibility which the fuzzy theory can be used to improve the performance of the parabolic SAR(Stop-And-Reverse) indicator in the trading systems for stock market. The simulation results with data of the KOSPI 200 future show that the occurred number of trading signals and the false signals in the proposed fuzzy SAR indicator is less than that in the conventional SAR indicator. In the conventional SAR system, the incremental value of the acceleration factor is usually setted as 0.02 and the maximum value of the acceleration factor is usually limited as 0.2. But in the proposed fuzzy SAR system, the incremental value and the maximum value of the acceleration factor are automatically adjusted by using the fuzzy rules, which are designed based-on the difference between short-term moving average and medium-term moving average and also based-on the slope of short-term moving average.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.342-345
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• 2004

An efficient hybrid ARQ scheme based on the rate compatible block turbo codes has been proposed, and its performance has been analyzed. System efficiency is improved by means of adaptive rate code transmission using channel information, trading off bit rate for channel codes, with resulting energy saving. The rate adaptation scheme improves power efficiency while keeping packet delay minimized. On the other hand, power dependant strategies reduce power consumption. Simulation results show that the benefits obtained are very encouraging. The modified hybrid ARQ schemes with the channel information and efficient retransmission structures highly improve the throughput performance in the satellite communication system. Therefore, proposed schemes could be used in future communication systems.

• Korean Management Science Review
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• v.14 no.2
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• pp.19-45
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• 1997

With the proliferation of telecommunication technologies, the traditional internal focus of information systems has shifted to entities beyond the organization's boundaries. In recent years, electronic data interchange (EDI) has come to revolutionize the way in which a business operates and relates to other businesses, Based on the establishment of trading activities, EDI systems have come to signify a speedy, efficient, and accurate means of electronically exchanging business transactions This study examines the current research trends in the area of EDI systems and identifies several issues for future research.55 articles in the EDI area from 1987 through 1996 were collected from related journals and proceedings of conferences. The articles are categorized by years and journals. The amount of EDI research has increased dramatically during the period of the study. Also, presented are the results of a content analysis of the articles. The findings not only provides general information about reserch methods, and direction of EDI study.

• Journal of KIISE:Software and Applications
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• v.32 no.8
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• pp.693-703
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• 2005

Given the local traders with pattern-based multi-predictors of stock prices, we study a method of dynamic asset allocation to maximize the trading performance. To optimize the proportion of asset allocated to each recommendation of the predictors, we design an asset allocation strategy called meta policy in the reinforcement teaming framework. We utilize both the information of each predictor's recommendations and the ratio of the stock fund over the total asset to efficiently describe the state space. The experimental results on Korean stock market show that the trading system with the proposed meta policy outperforms other systems with fixed asset allocation methods. This means that reinforcement learning can bring synergy effects to the decision making problem through exploiting supervised-learned predictors.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.19 no.38
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• pp.17-28
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• 1996

ISO 9000 Series International Standard have been established in 1987 and world trading patterns have changed into the request of ISO 9000 series approval. About 1100 domestic companies have currently obtained ISO 9000 series approval from domestic or foreign certification bodies. This paper presents the current status of ISO approval of domestic industries, a case study of a valve manufacturing company in Pusan, procedures for obtaining ISO approval, predictable effects as a result of approval, and recommendations.

• Proceedings of the CALSEC Conference
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• 1999.11a
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• pp.579-588
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• 1999

◆ 산업기술정보의 근간이 되는 4개 DB서비스 ◆ 전지역 정보를 통합한 포탈시스템과 지역특화시스템으로 구성 ◆ DB 정보검색(8개) 및 DB 통합검색 ◆ 분야별로 정의된 업체, 지자체의 기업지원뉴스 제공 ◆ Fax, E-mail에 기반한 상품정보 거래알선체제 ◆ 자기정보 등록체제(DB등록과 갱신) ◆ 지자체 파일 공유를 위한 표준화 ◆ DB 및 시스템 이용등에 관한 전문분석 통계체제 ◆ 국내 제조업체, 전문인력, 시험연구장비, 등의 디렉토리 관리 및 로봇검색 체제 (중략)

• Journal of Korean Society of Industrial and Systems Engineering
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• v.19 no.39
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• pp.81-88
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• 1996

As international commerce pattern changes toward the system of developed countries market competition, developing countries experience difficulties in international commerce market. Developed countries request their trading counterparts to obtain environment restriction. We also endure the environmental pollution due to industrialization. These environmental problems force Western Europe countries to install Environment Management System. This article presents description of development processes of ISO 14000 draft, compares ISO 9000 with 7750 requirements, and describes the common points and differences between ISO 9000 and 14000 draft.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.48 no.2
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• pp.75-82
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• 2016

The new climate regime for practical reduction in green house gas(GHG) emissions was launched in Paris at Dec. 2015. The Korea government would make various policies and plans in order to achieve the BAU 37 % emission reduction goals by 2030. In this study, the current situation and the possible corresponding methodology to the GHG emission reduction of Korea paper industry were investigated. Although the GHG emission reduction in KOREA paper industry has been successfully conducted compared with other industries until now, the more efforts for controlling GHG emission would be required to meet the new climate regime. The efficiency of various GHG reduction projects conducted by Korea paper companies was evaluated to find efficient way for GHG reduction. The certified methodologies of the external project based offset systems in Korea GHG emission trading scheme were also reviewed for providing the possible way to develope tailored methodology to the Korea paper industry.