• 대한산업공학회지
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• 제28권2호
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• pp.171-177
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• 2002

In this paper, we propose a new data fusion method to improve the performance of individual prediction models for time series data. Individual models used are ARIMA and neural network and their results are combined based on the weight reflecting the inverse of EWMA of squared prediction error of each individual model. Monte Carlo simulation is used to identify the situation where the proposed approach can take a vintage point over typical fusion methods which utilize MSE for weight. Study results indicate the following: EWMA performs better than MSE fusion when the data size is large with a relatively big amplitude, which is often observed in intra-cranial pressure data. Additionally, EWMA turns out to be a best choice among MSE fusion and the two individual prediction models when the data size is large with relatively small random noises, often appearing in tax revenue data.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2003년도 추계학술대회 및 정기총회
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• pp.39-42
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• 2003

A community can have a physical presence or can be formed from a group of people who communicate remotely via a conference call, a fixed Internet chatroom or instant message solution and most recently, a mobile handset. The mobile handset gives community members the advantage over fixed line or physical communities that they are not constricted by time or place as to when they can communicate with any members of their community. Operators, riding on the back of the SMS boom, are deploying community applications to increase both average revenue per user and customer loyalty. The purpose of this study is to find the effects of the characteristics of mobile community on the consumers'satisfaction and loyalty so that operators'participation in mobile community could be enhanced. A general model for the study was proposed with three independent variables. The variables are community usability(dialog and social support, information design, navigation, access), community sociability (purpose, people, policies), and mobile community content(location, personalization, immediacy, availability).

• 한국유기농업학회지
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• 제24권3호
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• pp.355-368
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• 2016

There are growing interests in environmental friendly cultivation for the matter of health concern. This study analyzes an economic efficiency of strawberry and tomato farming by considering the role of environmentally friendly cultivation. The Database of Rural Development Administration is used for strawberry and tomato farming households. We adopt a Bayesian stochastic frontier model to resolve a small sample property of the data. Empirical finding is that environmentally friendly cultivation improves the revenue of farming but the effect on net profit is not conclusive which calls for future research.

• 경영과학
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• 제27권2호
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• pp.67-79
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• 2010

When airlines sell the same seats on an air flight at different fares, demand for a fare class depends on demand for other fare classes due to demand dependency. Demand dependencies occur when customers will buy other fare class tickets if the originally requested fare were unavailable, or when customers postpone their purchase decisions in anticipation of reopening of the lower fare in the next period. Demand dependency as a result customer buying behavior has a considerable profit implication, which was ignored in many earlier studies. We investigate the impact of demand dependency on the optimal booking limits and the expected revenues under a single-period and a two-period setting. We show how to find optimal booking limits of the problem and provide numerical examples to illustrate the impact.

• 지능정보연구
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• 제6권2호
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• pp.49-62
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• 2000

본 논문은 향후 인터넷 사용의 많은 두 부분이 현재의 인간 사용자에서 지능형 에이전트로 옮겨져 갈 때 현 인터넷 사업 모형에 영향(Impact)으로 작용할 수 있는 요소들을 분석하고, 이로 야기되는 새로운 사업 모형의 출현 및 현 사업 모형에 예상되는 변화에 대하여 살펴보고자 한다. 지능형 에이전트로 인하여 인터넷 사업에 있어서 예상 가능한 주요 변화를 사업 모형 관점에서 제품, 서비스, 정보 흐름(Flow)의 변화, 참여자의 역할(Role)의 변화, 수익원천(Revenue)의 변화, 참여자간의 혜택 (Benefit)의 변화, 비용분담(Cost Distribution)구조 변화라는 다섯 가지 측면에서 현재의 인터넷 사업에 있어서 배너광고 모델, 가격책정 모델, 중개자 모델, 브랜드 및 명성 효과, 디지털 카르텔 등의 주요 현상과 결부시켜 살펴본다. 이를 통하여 향후 지능형 에이전트 기반의 사업 모형에 대비한 전략적 시사점(Imp1ications)을 제공하고자 한다.

• 자원ㆍ환경경제연구
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• 제11권3호
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• pp.493-513
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• 2002

This empirical study analyzed the policy effect of deregulation in oil product prices. To investigate the effect of deregulation, it is tested whether gasoline prices are determined by market power. Also, the role of government in gasoline tax system is investigated. The empirical analysis has been done by using error correction model. The major findings are as follows. First of all, no significant empirical evidence is found to support that the deregulation affects the determination of gasoline prices. Secondly, the short-term CIF elasticity is estimated to be 0.14. This finding implies that if CIF increases 10%, the gasoline prices increase 1.4%. Finally, the investigation on government role in deregulated market shows that the government has still exercise the power of control through the tax system. For example, the government is seemed to increase the gasoline price more than the increase amount caused by the international oil prices and the exchange rates, because of the intention to achieve the internal revenue increases and lead to gasoline conservation.

• 경영과학
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• 제16권1호
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• pp.51-61
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• 1999

Pipeline is an important transportation mode for ail products. The popeline transportation and storage rates affect the popeline usage, and the popeline usage also affects the transportation revenue and operating costs of the popeline. The purpose of our study is to develop a decision support system simulating popeline transportation and storage rates for maximizing the utilization and profitability of the oil pipeline and apply it to the real situation. To do this, a simulation model to help the decision maker decide the rates of the oil pipeline is first proposed. Second, a simulation program is developed, which enables the user to evaluate the various scenarios of oil transportation and storage rates. Finally, this program is applied to the case study of oil industry in korea.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1995년도 춘계공동학술대회논문집; 전남대학교; 28-29 Apr. 1995
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• pp.451-453
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• 1995

This paper examines characteristics of the accounting rate system whereby international telecommunications carriers settle net balances of account arising from bilateral traffic flows. Using a two stage game model, we explain problems in the system: growing traffic and payment imbalances, and resulting conflicts regarding accounting rates between carriers of, say, developed and developing countries. In this paper, we view the problems as a splitting-a-pie game in which one carrier cannot get more without a loss of the other, but total pie size depends upon the accounting rate. Therefore, a natural solution should be inevitably of a Coasian-type to establish a mutual agreement. In this regard, we first derive an efficient accounting rate, in the sense that it can make both carriers better off. Next we suggest some ways of attaining the efficient outcome. Regulatory and policy implications are also discussed.

• 한국경영과학회지
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• 제39권3호
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• pp.133-144
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• 2014

Naver, a leading search engine in South Korea, may show modified and reorganized search results for some trendy and popular keywords; when popular words such as the titles of soap operas and films are searched for,all the detailed and well-organized information regarding them can be presented. By recognizing that search engines may modify and reorganize search results for some popular keywords, we mathematically model the impact of the degree of modification of search results on the search engine's profit to derive its optimal modification degree. We show how the optimal degree of search result modification may change according to the different shapes of the search engine's advertising revenue function.

• 한국콘텐츠학회논문지
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• 제1권1호
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• pp.1-7
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• 2001

무선인터넷 도입 2년을 맞고 있는 국내 이동통신업계 가입자 수의 폭발적인 증가, 다양한 서비스의 제공, 벤쳐들의 모바일 분야 진출러쉬, 해외진출 등 외형적으로 괄목할 만한 성장을 보이고 있다. 하지만 시장참여자들은 하나같이 소문난 잔치에 먹을 것이 없다는 입장이다. 무엇이 문제인가\ulcorner 가장 큰 이유는 무선인터넷의 외적인 성장에 비해 각 player들이 만족할 만한 수익을 거두지 못한 데서 기인한 것이다. 인기에 영합해 모방지형의 단면적인 현행의 비즈니스 모델로는 지속적인 수익창출에 한계가 있기 때문이다. 일찍이 이러한 상황을 맞이한 일본의 경우, 비즈니스모델의 복합화를 통해 수익기반을 확대하거나 아예 바꾸는 등의 노력으로 이러한 상황을 타개해 나가고 있다. 현행 국내 무선인터넷 업계의 문제점 진단과 수익구조 확대를 위한 방안을 제시하고자 한다.