• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.143-148
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• 2010

A Statistical methods are used to determine the reliability of a Fuel Boost Pump for aviation. Failures are referenced from failure reports. The failure-free periods between successive failure events are evaluated in the form of weibull distribution. The results of analysis were calculated shape factor, scale parameter and mean time to failure. It found that the reason of failure is wear-out period.

• Journal of Navigation and Port Research
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• v.31 no.5 s.121
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• pp.353-359
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• 2007

Effective plan and operation managements can be established in advance if the traffic volume of container ship will be forecasted in the trend for container port's cargo volume to increase. At the viewpoint for marine traffic the number of incoming and outgoing container ship can be presumed in the long run and organised rational plan to deal the demand of marine traffic on the basis. Therefore, the paper estimated the future traffic volume of incoming and outgoing container ship for Busan, Gwangyang, and Incheon port on a forecasting data basis of container volume suggested in the national ports base plan. The trends of volume per ship on container were estimated with ARIMA models and seasonal index was computed. Thus the traffic volume of container ship in the future was estimated computing with volume per ship in 2011,2015, and 2020 respectively.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.154-154
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• 2023

수질모니터링은 수자원 보존과 공중 보건에 있어 매우 중요하다. 기후변화로 인한 이상강우와 산업화 등의 이유로 비점오염물질 및 오염원 배출량이 증가하여 하천과 호소에 영양염류가 증가하게 된다. 영얌염류의 증가로 하천에 부영양화 상태가 지속된다면 녹조발생 등으로 인해 생태계에 부정적 영향을 초래하게 된다. 또한 부영양화는 원수의 유기물량 증가로 인해 처리비용 증가, 이취미 문제 등 인간에게도 직접적인 문제를 유발한다. 특히 우리나라의 경우 하천 취수율이 높은 국가이며, 낙동강 중상류 지역에는 산업시설이 과도하게 밀집되어 있어 하천에 오염물질 유입이 되어 부영양화가 된다면 심각한 문제를 유발하게 된다. TN은 부영양화의 중요한 지표다. 우리나라의 TN 측정은 시료 채수 후 실험실에서 수질오염공정 시험기준에 따라 진행이 된다. 실험실 분석은 TN 농도를 분석하는 일반적인 방법이며, 정확한 검출 및 정량화를 목표로 한다. 하지만 이러한 방식은 정교한 장비를 갖춘 전문 실험실 및 전문 인력을 필요로 한다. 환경부에서 주요 하천에 수질측정망을 설치하여 수질현황에 대한 종합적인 조사를 통해 수질변화 추세를 파악하는 것이 가능하지만, 실시간 TN 농도를 감지하는데 매우 제한적이다. 현재 조사방식은 TN 농도 증가로 인한 문제에 대해 초기대응을 하기에는 한계가 있다. 최근 센서의 발전으로 다양한 항목을 신속하고 지속적으로 모니터링 할 수 있게 되었다. TN에 대한 직접적인 센서 모니터링은 불가능 하지만 여러 측정 항목이 TN과 상관관계가 있는 것이 여러 연구에서 입증되었다. 이러한 결과를 바탕으로 본 연구에서는 오염도가 높은 낙동강을 대상으로 TN 예측에 대한 기초 연구를 진행하였다. 과거 측정된 자료를 활용하여 센서로 측정 가능한 항목을 통해 TN 예측을 진행하며, 실제 활용을 위해 회귀식을 도출하고자 한다. 최근 환경부에서 실시간 수질 현황 및 오염도를 파악하기 위해 자동측정망 지점을 늘리는 추세인데, 본 연구의 결과를 활용한다면 실시간 TN 예측에 대한 기초자료 활용될 수 있을 것으로 판단된다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.1039-1042
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• 2006

Because many corporations computerize process figure enemy who is introducing eCRM fast and are used mainly at past by purpose to detect and analyze and forecast systematic analysis of customer information and various pattern of customer recently, ordinary peoples are trend that is alternated gradually by data mining that can drawand forecast result of good quality easily. Field that this data mining is used representatively is eCRM. In this treatise customer data of A discount store and sale data of 1 years experimenting that forecast customer contribution to base next year through data mining actuality data and data mining through comparison with predicted data are how effective to eCRM prove.

• Journal of Korea Port Economic Association
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• v.37 no.3
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• pp.1-17
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• 2021

Forecasting the daily volume of container is important in many aspects of port operation. In this article, we utilized a machine-learning algorithm based on decision tree to predict future container throughput of Busan port. Accurate volume forecasting improves operational efficiency and service levels by reducing costs and shipowner latency. We showed that our method is capable of accurately and reliably predicting container throughput in short-term(days). Forecasting accuracy was improved by more than 22% over time series methods(ARIMA). We also demonstrated that the current method is assumption-free and not prone to human bias. We expect that such method could be useful in a broad range of fields.

• Proceedings of the KAIS Fall Conference
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• 2010.11b
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• pp.559-563
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• 2010

황해경제자유구역은 환황해권 첨단기술의 국제협력 거점 조성이라는 비전과 국제수준의 첨단기술산업 클러스터 육성, 대 중국 수출입 전진기지 및 부가가치물류 육성을 목적으로 2007년 지정되어 사업이 추진 중에 있다. 황해경제자유구역 반경 15km 이내에 7개의 산업단지가 입지하고 있어 충남 서북부지역의 산업집적도는 날로 증가하고 있는 추세이다. 그러나 이를 지원할 주요 인프라 중 하나인 물류단지 시설은 전무한 실정이며 황해경제자유구역을 포함한 충남 서부지역의 물류거점 개발은 매우 미약하다. 본 연구의 목적은 첫째, 서해안 지역 물류거점 단지 조성의 필요성을 검토하고, 둘째, 물류단지 규모 및 성격을 부여하며, 셋째, 물류단지 도입기능을 설정하고자 한다. 연구목적을 달성하기 위해 물동량 수요예측과 주변지역 연계방안을 토대로 황해경제자유구역의 배후물류단지의 필요성과 조성방안을 제안하고자 한다.

• Convergence Security Journal
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• v.14 no.5
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• pp.37-47
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• 2014

A Trojan malicious code is one of largest malicious codes and has been known as a virus that causes damage to a system as itself. However, it has been changed as a type that picks user information out stealthily through a backdoor method, and worms or viruses, which represent a characteristic of the Trojan malicious code, have recently been increased. Although several modeling methods for analyzing the diffusion characteristics of worms have proposed, it allows a macroscopic analysis only and shows limitations in estimating specific viruses and malicious codes. Thus, in this study an ESP model that can estimate future occurrences of Trojan malicious codes using the previous Trojan data is proposed. It is verified that the estimated value obtained using the proposed model is similar to the existing actual frequency in causes of the comparison between the obtained value and the result obtained by the Markov chain.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.10
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• pp.2923-2934
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• 2009

This paper presents study on technological forecasting of Next-Generation Display technology. Next-Generation Display technology is one of the emerging technologies lately. So databases on patent documents of this technology were analyzed first. And patent analysis was performed for finding out present technology trend. And the forecast for this technology was made by growth curves which were obtained from forecast models using patent documents. In previous study, Gompertz, Logistic, Bass were used for forecasting diffusion of demand in market. Gompertz, Logistic models which were often used for technological forecasting, too. So, two models were applied in this study. But Gompertz, Logistic models only consider internal effect of diffusion. And it is difficult to estimate maximum value of growth in two models. So, Bass model which considers both internal effect and external effect of diffusion was also applied. And maximum value of growth in Gompertz, Logistic models was estimated by Bass model.

• Journal of Distribution Research
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• v.6 no.2
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• pp.41-64
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• 2002

Since its market opening in the year 1996, Korea's retail sector has witnessed the emergence of various new retail formats such as discount stores and Internet shopping malls. Given the competition among various retail formats, it is needed to analyze the previous trends and to measure the future potential of the market with more careful economic models. Using Time Series Analysis on Korean economy and distribution industry, we aim to economic models to follow the trends and to measure the future growth of competing retail formats such as department stores, discount stores and convenience stores. We have found that the growth of department stores, convenience stores and specialty store format is very closely related with the private consumption expenditure. On the other hand, private consumption expenditure is not a good variable to explain the growth of discount stores and the supermarket sector. Following an extensive data analysis, three year forecasting of Korean distribution market including six different retail sectors is proposed. In addition, several discussion points including statistical classification of retail formats are argued.

• Korea journal of population studies
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• v.33 no.1
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• pp.161-189
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• 2010

Dealing with uncertainty has been a critical issue in demographic and population forecasting since 1980. This study reviews methodological developments in demographic and population forecasting over the last several decades. First, this study reviews the important issue of the uncertainty surrounding demographic forecasts. Several limitations of the traditional scenario approach to dealing with uncertainty are also discussed. Second, in forecasting demographic processes such as mortality, fertility, and migration, three approaches of stochastic forecasting are identified and discussed: expert judgment, statistical modeling, and analysis of historical forecast errors. Finally, this study discusses the current issues and directions for future research in stochastic demographic forecasting.