• 유통과학연구
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• 제14권1호
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• pp.93-102
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• 2016

Purpose - The purpose of paper is studying the static and dynamic side for long-term memory storage properties, and increase the explanatory power regarding the long-term memory process by looking at the long-term storage attributes, Korea Composite Stock Price Index. The reason for the use of GPH statistic is to derive the modified statistic Korea's stock market, and to research a process of long-term memory. Research design, data, and methodology - Level shifts were subjected to be an empirical analysis by applying the GPH method. It has been modified by taking into account the daily log return of the Korea Composite Stock Price Index a. The Data, used for the stock market to analyze whether deciding the action by the long-term memory process, yield daily stock price index of the Korea Composite Stock Price Index and the rate of return a log. The studies were proceeded with long-term memory and long-term semiparametric method in deriving the long-term memory estimators. Chapter 2 examines the leading research, and Chapter 3 describes the long-term memory processes and estimation methods. GPH statistics induced modifications of statistics and discussed Whittle statistic. Chapter 4 used Korea Composite Stock Price Index to estimate the long-term memory process parameters. Chapter 6 presents the conclusions and implications. Results - If the price of the time series is generated by the abnormal process, it may be located in long-term memory by a time series. However, test results by price fixed GPH method is not followed by long-term memory process or fractional differential process. In the case of the time-series level shift, the present test method for a long-term memory processes has a considerable amount of bias, and there exists a structural change in the stock distribution market. This structural change has implications in level shift. Stratum level shift assays are not considered as shifted strata. They exist distinctly in the stock secondary market as bias, and are presented in the test statistic of non-long-term memory process. It also generates an error as a long-term memory that could lead to false results. Conclusions - Changes in long-term memory characteristics associated with level shift present the following two suggestions. One, if any impact outside is flowed for a long period of time, we can know that the long-term memory processes have characteristic of the average return gradually. When the investor makes an investment, the same reasoning applies to him in the light of the characteristics of the long-term memory. It is suggested that when investors make decisions on investment, it is necessary to consider the characters of the long-term storage in reference with causing investors to increase the uncertainty and potential. The other one is the thing which must be considered variously according to time-series. The research for price-earnings ratio and investment risk should be composed of the long-term memory characters, and it would have more predictability.

• 대한전기학회논문지:전력기술부문A
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• 제53권7호
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• pp.414-419
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• 2004

In TWBP new uncertainty will be increased. Risk management is risen to a important problem. Vesting contract makes market Players trade at fixed price in TWBP early stages. In the case of advanced country, market players manage risk with a future contract. When a risk management method moves from vesting contract to future contract, it may have to use together two contracts for schedule period. In this paper, risk management strategy that use vesting contract and forward contract at the same time is proposed.

• 한국통신학회논문지
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• 제32권6B호
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• pp.390-401
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• 2007

본 연구는 2000년 1월부터 2005년 12월까지의 월별 시계열 자료를 이용하여 통화수요의 요금탄력성을 추정하고 분석하는 것을 목적으로 한다. 본 연구에 사용된 데이터는 M발신통화량, M발신요금지수, L발신요금지수, 소득수준, 가입자수 등의 자료가 이용되었다. 본 연구에서는 요금탄력성의 추정을 위하여 크게 두가지 계량적 방법을 사용하였다. 첫번째는 설명변수에 종속변수의 시차를 고려한 동태적인 로그선형모형을 일반화된 적률추정법(GMM)을 이용하여 장 단기 탄력성을 추정하였다. 두번째는 Box-Cox변환모형을 응용하여 시간의 변화에 따른 요금탄력성의 변화추이를 추정하였다. 연구결과 L발신요금지수는 요금탄력성의 중요한 변수로서 포함하지 않은 경우 과대추정될 수 있음을 알 수 있었다. Box-Cox변환모형을 이용한 추정결과 요금탄력성은 시간의 경과에 따라 감소하는 추세를 나타내고 있었으며, 이는 이동통신서비스가 점점 더 필수재로 전환을 하고 있는 것을 나타내는 것으로 분석된다.

• Journal of Electrical Engineering and Technology
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• 제8권6호
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• pp.1251-1260
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• 2013

This paper presents the optimal scheduling of hourly consumption in a residential community (community, neighborhood, etc.) based on real-time electricity price. The residential community encompasses individual residential loads, communal (shared) loads, and local generation. Community-aggregated loads, which include residential and communal loads, are modeled as fixed, adjustable, shiftable, and storage loads. The objective of the optimal load scheduling problem is to minimize the community-aggregated electricity payment considering the convenience of individual residents and hourly community load characteristics. Limitations are included on the hourly utility load (defined as community-aggregated load minus the local generation) that is imported from the utility grid. Lagrangian relaxation (LR) is applied to decouple the utility constraint and provide tractable subproblems. The decomposed subproblems are formulated as mixed-integer programming (MIP) problems. The proposed model would be used by community master controllers to optimize the utility load schedule and minimize the community-aggregated electricity payment. Illustrative optimal load scheduling examples of a single resident as well as an aggregated community including 200 residents are presented to show the efficiency of the proposed method based on real-time electricity price.

• Journal of Power Electronics
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• 제16권3호
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• pp.994-1003
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• 2016

Two major obstacles in the utilization of electrical vehicles are their price and range. The collaboration of direct torque control (DTC) with induction motor (IM) is preferred for its low cost, easy implementation, and parameter independency. However, in terms of edges, the method has drawbacks, such as variable switching frequency and undesired current harmonic distortion. These drawbacks result in acoustic noise, reduced efficiency, and electromagnetic interference. A feed-forward approach for stator-flux-oriented DTC with space vector pulse-width modulation is presented in in this paper. The outcome of the proposed method is low current harmonic distortion with fixed switching frequency while preserving the torque performance and simple application feature of basic DTC. The method is applicable to existing and forthcoming IM drive systems via software adaptation. The validity of the proposed method is confirmed by simulation and experimental results.

• 수산경영론집
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• 제29권2호
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• pp.111-141
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• 1998

Why are auctions so prevalent in fisheries fields\ulcorner One answer is, perhaps, that fisheries products have no standard value. The price of any catch of fish (at least of fish destined for the fresh fish market) depends on the demand and supply conditions at a specific moment of time, influenced by prospective market developments and prices must be remade for each transaction. There are various auction schemes including written-bid method in Korea. It is difficult to make decision the application of auction selling in market distribution. One reason is the absence of adequate data on which to base firm statements. There is very little precise information about the relative volume handled by auction scheme as compared with other sales schemes Because of the paucity reliable data, one must depend largely on qualitative in attempting to above this problem. This paper is designed to examine which auction scheme is more efficient as a economic tool by introducing the three auctions, as samples, utilized in Koheung peninsula. Koheung coast with abundant fisheries resource, locates on the Middle-South part in Korea and has three auction firm operating by fisheries cooperatives. fur selling of dry fish included sea weed, live fish and fresh fish respectively, As a result, 1 found that there are three interesting auction schemes as follow : 1. More than one winners are selected as buyers. The highest bidder can at first get fishes he wants to buy, second winner can get surplus fishes after the highest bidder employes one's privilege with the highest pay, and next winner would be a buyer if fishes would be left in sequence after being sold with higher price. Every fisherman can sell one' s fishes with equal unit price if he delivery it to the winner within one day. Therefore, all the vendors feel they are equal members of fisheries cooperation. 2. Written-bid pricing on the cover of handy book. It is easy to write and to erase the figure more than on the small black board, and is convenient also to keep in the pocket. 3. Auctioning on the fixed platform with fixed fish tank is a very fast auction scheme in spite of short displaying time. Auctioneer presides bidding at one place on the fixed platform, instead of moving, vendors should carry a container of live fishes in the fish tank into showing table in front of would-be buyers and auctioneer. Although the applicability of the auction system to a marketing problem depends in part on subjective considerations by those making decision, basically it is a matter of comparative economic efficiency. In general, if the scheme maximizes returns in relation to the effort expanded by both buyers and sellers, it will be utilized. If it does not, a more efficiency may take place over a period of time, but, even more important, those making decisions may become aware of the potentialities of new schemes. Therefore, in order to applicate the three interesting auction schemes introduced in this paper to other fisheries market, it is necessary not only to analyze many other auction schemes but also to compare the economic efficiency those schemes utilizing in other fisheries market.

• Journal of Forest and Environmental Science
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• 제19권1호
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• pp.108-123
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• 2003

1992년 리우회의 이후 국제적으로 환경자원의 중요성이 인식되면서 환경자원에 대한 가치를 정량화하고자 하는 움직임이 본격화 되었다. 우리나라 역시 이러한 국제적인 추세에 영향을 받으면서 1990년초부터 비시장재화의 가치를 평가하고자 하는 연구가 본격적으로 시작되었다. 또한 1999년에 예비타당성조사가 도입되면서 대규모건설사업 수행 전에 환경자원의 가치까지 고려한 비용편익분석이 실제로 이루어지고 있다. 하지만 환경자원에 대한 가치평가 방법이 아직 정립되지 못한 실정이다. 본 연구에서는 환경자원의 가치 평가를 위한 이론과 주요 평가 방법을 소개하였다. 이론에서는 환경자원의 가치를 수요함수와 생산함수차원에서 검토하고 이들 두 함수가 함께 고려된 시장에서 최적 수준을 도출하였다. 평가 방법에서는 시장의 특성에 따라 대표되는 평가 방법인 여행비용법, 만족가격법, 가상가치평가법을 소개하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.111-112
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• 2007

This paper presents the capacity payment in electricity power markets. The capacity payment (CP) needs to recover fixed costs. But most CP is allocated by energy policy. So, this paper analysis CP using capacity proportion and Reliability Pricing Model (RPM). The capacity proportion method uses base capacity price and supply available capacity. The RPM method uses value of each region and operation attribute of each generator.

• 대한토목학회논문집
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• 제33권2호
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• pp.771-780
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• 2013

과거에 시행한 심사제도는 입찰참가자격사전심사 및 기본설계평가와 가격평가로 구분하여 최종 낙찰자를 선정하였으나, 2010년 1월 1일부터 현재까지 턴키 대안입찰공사는 설계 적합 최적가 방식, 종합 평가 방식(입찰가격조정, 설계점수조정, 가중치기준), 확정금액 최상 설계 방식의 낙찰자 결정방식을 선택하고 있다. 이러한 제도적인 문제로 발주기관은 동일 유사한 공사에 대해 서로 다른 낙찰자 결정방식을 적용하고 있는 사례가 종종 있어 왔다. 그러므로 이 연구는 국내에서 시행된 토목부분 턴키 대안입찰공사 발주현황, 건수 및 수주실적, 공종별 발주기관별 수주실적, 세부방식 가중치 낙찰자 수주실적 등의 분석을 통해 국내 턴키 대안입찰공사 실정에 적합한 낙찰자 선정기준을 제시하였다.

• 한국산림과학회지
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• 제61권1호
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• pp.53-59
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• 1983

임지(林地)를 생산적(生産的)인 용도(用途)로 개발(開發) 이용(利用)케 하는 전제조건(前提條件)은 먼저 임지(林地)의 거래가격(去來價格)이 합리적(合理的)인 수준(水準)에서 책정(策定)되어야 하고, 다음은 개별투자가(個別投資家)가 임지(林地)를 개발(開發)코자 할 때 효율적(效率的)이고, 경제적(經濟的)인 자본(資本)의 사용(使用)이 보장(保障)될 수 있는지의 여부(與否)가 판명(判明)되어야 한다. 따라서, 본교(本橋)에서는 임지(林地)의 거래가격(去來價格)을 추정(推定)하는 방법(方法)과 개별자본가(個別資本家)의 사업추진(事業推進) 타당성(妥當性)에 대(對)한 이론적(理論的)인 방법론(方法論)을 제시(提示)하였다.