• Ocean and Polar Research
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• v.43 no.4
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• pp.295-306
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• 2021

A field scale productivity analysis is required for the development of gas hydrate in marine sedimentary layers to verify the field applicability of production techniques and to improve productivity. In this study, the productivity resulting from the application of depressurization using multi-wells for the development of gas hydrate in the Ulleung Basin, East Sea of Korea, was determined. A numerical analysis model reflecting the conditions of candidate sites for the Ulleung Basin was constructed, and the productivity and dissociation behavior were comparatively analyzed. The pressure propagation and gas hydrate dissociation region by the multi-wells were wider and the productivity was higher than that of a single well. Different depressurization effects according to the spacing of multi-wells affected productivity. The results provide basic data for productivity analysis when establishing a field test production plan for the Ulleung Basin.

• International Area Studies Review
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• v.13 no.2
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• pp.325-344
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• 2009

Korean overseas construction contracts reached 40 billion dollars in 2008. In this paper, the economic factors of "the record high growth since 1980's 'overseas construction boom' is investigated. Firstly, most of the contracts were made in the Middle East OPEC countries which made large scale construction investments with the increasing oil revenues... Secondly. large portion of the contracts is heavy industrial plants, in which Korean construction firms have enjoyed comparative advantages. Thirdly, Korean construction firms have been forced to pay attention to the overseas markets, due to the domestic slump of the construction industry.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.117-119
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• 2010

미래 전쟁은 과거의 재래식 전쟁과는 판이하게 변화된 환경 속에서 새로운 전투 형태와 방법으로 전개될 것이다. 특히, 첨단 기술의 급속한 발전은 전장에서 싸우는 방법을 변화시키는 주요 요인이라고 할 수 있다. 전장에서 적을 먼저 발견하고 타격하기 위해서는 실시간 표적 획득 및 첩보 수집과 정확한 상황판단 및 적시적인 지휘가 요구되기 때문에 정보 수집 자산이 부족한 사 여단급 부대를 대상으로 감시 정찰 센서 네트워크 시스템을 구축하는 것이 필요하다. 그러나 평시 체계와 전시 체계의 운용 개념이 부족한 상태에서 실 세계에 적용하는 것은 유지비용의 증가, 감지 오류, 야전 환경과의 부적합 등을 야기한다. 따라서, 이러한 문제점의 해결 대안으로 이 논문에서는 지상군 작전에서 적의 조기 발견과 전장 가시화에 필요한 전장감시 센서 네트워크 시스템을 위한 상황 인식 프레임 워크를 제안하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.402-402
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• 2023

상수관망은 충분한 양질의 수돗물을 공급하기 위한 사회기반 시설물이다. 상수관로의 노후화, 누수 등은 수도 사고 발생의 가능성을 증가시키고, 수돗물 안전성에 대한 신뢰도를 감소시킨다. 수돗물 공급 전 과정을 인공지능(AI), 정보통신기술(ICT)과 결합한 지능형 상수도관 예측 및 관리 시스템을 구축하여, 상수도 수질 사고를 조기에 감지하고 사전에 취약지점을 예측할 필요가 있다. 이를 위해서는 상수관로의 위험도를 평가하기 위한 체계적인 데이터와 기준이 필요하다. 본 연구에서는 상수관로의 위험도 예측모델을 개발하기 위해 상수관로 위험도와 관련된 평가 인자를 선정하고 분류하였으며, 각 인자의 명확한 기준을 제시하였다. 국내·외 상수도 위험도 평가 항목에 대한 자료를 비교 및 분석하였고, 전문가 자문을 통해 인자를 정립하여 상수관로 위험도 평가 지표를 개발하였다. 개발된 평가 지표의 현장 적용성과 실효성 검증을 위해 정량적인 데이터 확보가 가능하고 상태를 평가할 수 있는 대상 지역을 선정하였다. 문헌 자료의 평가항목들과 전문가 의견을 바탕으로 상수관로 위험도 평가 인자를 31개의 직접 인자와 5개의 간접 인자로 구분하였고, 인자별 평가 기준을 제시하였다. 직접 인자는 노후화 정도를 파악할 수 있는 노후도 평가 항목, 지역 특성을 반영한 토양 부식성 항목, 실시간으로 측정하여 결과를 제공하는 실시간 계측 항목, 직접적인 수질 결과를 제공하는 정수장 수질 항목, 상수관로의 건전성을 평가하는 자산관리 항목으로 분류하였다. 추후, 위험도 평가 운용을 위한 알고리즘을 개발하면 상수도 사고 위험에 대한 예방 및 대응 전략을 수립할 수 있을 것으로 기대된다.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.05a
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• pp.305-307
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• 2023

현재 제조업에서 설비 라인 증축 및 최적화를 위해서는 공정 분석과 설비 시스템 테스트가 요구되며, 많은 시간과 비용이 소요된다. 이러한 문제를 해결하기 위해, 가상의 설비모델을 이용해 설비검증과 라인 테스트를 수행할 수 있는 다양한 CPS(Cyber Physical System)가 연구되고 있다. 본 논문에서는 다양한 설비 이해관계자 사이의 상호운용성을 확보하기 위해 독일의 Industry 4.0에서 제안한 표준 설비 명세인 AAS(Asset Administration Shell)를 활용한 CPS 구현을 제안한다. SMT(Surface Mounting Technology) 라인 중 Screen Printer를 대상으로, 총 3개의 서브 모델(Sub model)과 17개의 속성(Property)을 AAS 명세하고 이를 이용한 CPS를 구현하는 사례연구를 수행했다. 제안 방법은 표준명세를 활용한 제조 분야 CPS 구현에 적용될 수 있다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.4
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• pp.190-198
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• 2023

The purpose of this study was to propose an operational concept for a ship in a fleet equipped with an interceptor missile system, a naval surface to air defense system, and to develop a simulation program that reflects it. The results of the defense activities of other ships in the fleet can be reflected by receiving information about the status of the enemy missiles. The allocation of defensive assets is based on the survival probability of the ship, not on the destruction of enemy attacks, which can be obtained as the product of the expected survival probability for each enemy missile. In addition, the concept of predicted survivability was introduced to assess the loss of future defense opportunities that would result from assigning a new command. A simulation program was also developed as a tool for realizing the proposed concept of operations, which generated cases.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.66-79
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• 2016

A discussion has recently emerged over the increase of approvals of K-REITs, which is concluded on the basis of how to raise funds for business activity, fulfill the expected rate of return and maximize the management of managing investment funds. In addition, corporations need to acknowledge the necessity of the capital structure reflected in the current economic environment and decision-making processes. This research analyzed the characteristics by investment types and influence factors about the debt ratio of K-REITs. The data were collected from general management about business state, investment, and finance from 2002 to 2015 in K-REITs (except for the GFC period of 2007~2009). The results of the research demonstrated the high ratios of the largest shareholder characteristics, which are corporation, pension funds, mutual funds, banks, securities, insurance, and, recently, the increasing ratio of the largest shareholder and major stockholder. The investment of K-REITs is increasing the role of institutional investors that take a leading development of K-REITs. The behaviors of simultaneous investment of institutional investors were analyzed to show that they received higher interest rates than other financial institutions and ran in parallel with attraction and compensation. The results of the multiple regressions analysis, utilizing variables about debt ratio were as follows. The debt ratio showed a negative (-) relation that profitability is increasing, which matches the pecking order theory and trade off theory. On the other hand, investment opportunities (growth potential) showed a negative (-) relation and assets scale that indicated a positive (+) relation. The research results are reflected as follows. K-REITs focused on private equity REITs more than public offering REITs, and in the case of financing the capital of others, loan capital is operated under the guarantee of tangible assets (most of real estate) more than financing of the stock market. Further, after the GFC, the capital of others was actively utilized in K-REITs business, and the debt ratio showed that the determinant factors by the ratio and characteristics of the largest shareholder and investment products.

• Journal of Service Research and Studies
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• v.12 no.2
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• pp.135-151
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• 2022

This study was conducted on a servicism basis as a study to build the management wisdom of Korea as an asset of human society. The case of the founding and development of the Republic of Korea, which developed into one of the world's leading powers with unprecedented rapid growth despite the devastating three-year war immediately after its founding, is an important subject of study. This study conducted a macroscopic analysis. In the process of carrying out the founding activities, it was confirmed that the original idea inherent in Koreans was the Taegeuk idea of the National Flag. The founders of the Republic of Korea consciously or unconsciously adopted the Taegeuk ideology as the founding ideology. It can be said that the Taegeuk ideology has led to greater success because it is based on the service philosophy, which is the common truth of mankind. In this study, the process of preparing for the founding of the Republic of Korea, which was founded by accepting a new maritime civilization from a country with a long continental civilization, the process of national foundation, and the process of operating the country after its founding were analyzed as a whole. In particular, it discovered the excellent wisdom of the founders who appropriately utilized the strengths of continental and maritime civilizations in necessary situations, and confirmed that the dynamic operating model of development through fierce competition between the two opponents was a success factor for high-speed national development. It requires great wisdom for Koreans with diverse ideological backgrounds and unique personalities to unite to establish and run a nation. This is because fierce competition and cooperation must be carried out at the same time. The great wisdom of the founding of the Republic of Korea was able to be demonstrated because the Taegeuk ideology was acting as a common basic ideology for Koreans. Taegeuk ideology, the source of wisdom that Korea has developed under constant tension, can be capitalized as human wisdom, and additional case studies are needed.

• Journal of the Korean Society for Railway
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• v.16 no.1
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• pp.65-70
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• 2013

In many cases, operation of regional trunk lines is not profitable to railway operators. Nevertheless, railway operators are under pressure to manage regional trunk lines running under deficits, to better serve public interests. Given this situation, railway operators need to optimize assets by adjusting train schedules or changing the number of trains running. When railway operators judge the operation of a regional trunk line, the B/C ratio is generally used as a management index. This ratio is not considered part of strategic operational policy over the long term, and excessively influenced by the aspects of supply and demand over the short term. Accordingly, this study focused on indices that might be used to prevent worsening deficits and provide long term strategic operation policies, main indices to better measure economic situations, and auxiliary indices to supplement the main index. The main indices were measured in conventional ways to target experts and employees. This study presents quantitative standards, which are intended to be used to create itemized criteria through an Analytic Hierarchy Process, for better decision-making.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.112-119
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• 2016

This study aims to examine propping by the controlling shareholders and the corporate value of Korean firms with agency problems and propping perspectives. Propping refers to a transfer of resources from a higher ownership firm to a lower ownership firm, in order to prevent the latter from going bankrupt. This study used a sample of 4,077 companies listed on the KRX data exchange from 2004 to 2014. We used proxy variables such as long-term supply contracts, asset and business sales, credit facilities, loans, and equity investments to affiliates as wealth transfer instruments of the controlling shareholders. We found that propping occurred by the equity investment of affiliates in Korean firms. Also, we found that the Korean firm's value was decreased by the affiliate equity investment.