• Journal of Chest Surgery
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• 제35권1호
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• pp.20-26
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• 2002

배경: 관상동맥수술에서 동맥도관의 장점이 확인되면서, 우위망동맥(right gastroepiploic artery)의 사용이 점차 늘고 있다. 우위망동맥을 근위부 협착이 심하지 않은 관상동맥에 유근이식편(pedicled uaft)으로 사용할 경우 역행성 혈류가 발생할 수 있다는 보고들이 많아지면서, 수술 전에 역행성 혈류를 예측하려는 시도가 계속되고 있다. 본 연구는 정상 관상동맥과 우위망동맥 사이에 생리적으로 존재하는 혈압차(Vessure difference: PD)를 증명하고 협착 관상동맥의 경협착 맥압차(trans-stenosis pressure gradient: TSPG)와의 상관관계를 분석함으로써, 우위대망동맥을 유근이식편으로 사용할 때 역행성 혈류가 발생할 수 있는 근위부 협착의 정도를 예측하기 위해 고안되었다. 대상 및 방법,. 1998년 7월부터 1999년 2월까지 관상동맥 조영술에서 정상으로 판정된 12명의 환자에서 우관상동맥과 우위망동맥(혹은 복강동맥; celiac uef)의 압력을 측정하여 혈관 사이의 혈압차(PD)를 측정하였다. 관상동맥협착이 확인된 29명의 환자에서는 경협착 맥압차(TSPG)를 측정하였다. 결과:정상 환자군에서 우관상동맥과 우위망동맥의 수축기혈압은 143$\pm$23 : 134$\pm$17 mmHg(p<0.005), 이완기혈압은 74$\pm$13 : 73$\pm$14 mmHg(p=NS), 평균혈압은 100$\pm$16 : 97$\pm$15mmHg이었다(p<0.05). 동맥 사이의 압력차(PD)는 수축기혈압 -8~25 mmHg, 이완기혈압 -4~7 mmHg, 평균혈압 -1 ~ 10mmHg이었다(p<0.05). 관상동맥협착 환자군에서 경협착맥압차(TSPG)는 75% 미만의 협착의 경우 -4~l9(7$\pm$5.8) mmHg이고, 75% 이상의 협착의 경우 7~74(27$\pm$18.3) mmHg이었다(p<0.005). 75% 이상의 협착에서는 관상동맥의 경협착 맥압차(TSPG)가 우위망동맥과의 생리적 혈압차(PD) 보다 크고, 협착 원위부 관상동맥의 혈압도 우위망동맥 혈압보다 유의하게 낮았다(p<0.001). 결론: 관상동맥우회술 후 역행성 혈류의 발생원인이 우위대망동맥과 협착하부 원위부 관상동맥 사이의 압력차이라고 가정할 때, 본 연구의 결과는 우위대망동맥을 75%이상 협착병소에 유근이식편으로 사용할 경우 역행성 혈류가 발생할 가능성이 적어진다는 것을 시사할 수 있다.

• 한국콘텐츠학회논문지
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• 제6권7호
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• pp.111-118
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• 2006

이 연구의 목적은 우리나라의 3대 멀티플렉스 (CGV, 롯데시네마, 메가박스 )의 2002 년부터 2004 년까지의 효율성을 확인하는 것이다. 우리나라의 영화산업은 1998 년부터 시작한 멀티플렉스의 건설이후에 극심한 도전에 의해 변해왔다. 이 연구는 우리나라의 영화 시장과 멸티플렉스에 대한 실태를 제시하고 영화 산업에서 급격한 관객의 증가가 왜 열어났는지 제시하였다. 마지막으로 이 연구는 영화 산업의 경쟁력을 확보하기 위하여 기술적, 규모 효율성을 DEA( 자료포락분석 )의 방법으로 밝혀내었다.

• 유통과학연구
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• 제15권12호
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• pp.31-39
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• 2017

Purpose - The purpose of the paper is to examine shipping markets exposed on severe competition after Lehman Brothers crisis in 2008, and look for some alternatives to get it over. Research design, data, and methodology - The research method to be applied is first to look into world economic situations, and then to investigate supply and demand of shipping markets, and strategic alliances as alternatives, which lead to some implication and lessons. Results - After the fierce world economic situations after Lehman Brothers crisis in U.S, it has shown that world economic output and growth is not like that of previous years. It is periods of new normal. Then, shipping has been influenced by less trade volumes and, however, shipping capacity has reached to overcapacity in supply terms. Therefore rates down is clear, and it should be needed new way of getting it over market situations. In this sense, strategic alliance is answer for overcoming difficult markets. Conclusions - From the careful look at all situations, such as world economic situation, supply and demand of shipping market, deep understanding for strategic alliances of shipping, it has reached to conclusion that strategic alliance is only answer for difficult shipping markets.

• 유통과학연구
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• 제16권10호
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• pp.31-38
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• 2018

Purpose - The purpose of this paper is to seek some alternative to overcome difficult shipping situations for overcapacity pursuing economy of scale, which is widely spread in world shipping. Research design, data, and methodology - The research method to be adopted is first to review evolution of larger ships in terms of theoretical overview, and shipping market is examined, and it is studied some problems and solutions in relation to larger ship as field research aspects. Results - Supply and demand of shipping market is flexible and unpredictable nature of market. Sometime fierce competition has spread out the market, and shipowner may deploy mega ship in terms of economy of scale, etc., to overcome the difficult market situations. Both carrier and shipper have their own positions in this matter concerned. However, it causes some problems in the market including port matters, etc. Therefore, it is asked to solve this problems of larger ship employed in the markets, throughout shipping alliances, etc. Conclusions - Over tonnage done by larger ship has caused some problems in the shipping markets, forming monopolistic market by small number of larger shipping companies, destroying oligopolistic nature of shipping business, therefore, the answer is strategic alliance to collaborate each other.

• The Korean Journal of Ecology
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• 제9권3호
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• pp.123-133
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• 1986

Black pine, Pinus thumbergii, stands in southwestern Korea were investigated. The black pine forest with 90 percent or more in the relative basal area (black pine basal area/whole pine basal area, RBA) was found in the coastal area. However, from the coastal area to the inland. RBA of the pine was decreased because the competition with red pine (P. densiflora) and/or pitch pine (P. rigida). In 25 year-old plants at the coastal areas, the wood volume of black pine is twofold or more than that of red pine, fourfold or more than that of pitch pine. The optimum rotation period for the maximum yield of black pine is estimated to take 35 years, based on the site index calculated. The optimal temperature for the pine plantation in Korean peninula should be the area in over 105。C.month in warmth index. And the soil conditions with 50% of RBA or over were 0.025%~0.151% of soil salinity, 3~6% of organic matter content, pH value 4.50~5.04, 8.5~11.0 me/100g of C.E.C..

• 한국항해항만학회지
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• 제33권7호
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• pp.483-490
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• 2009

In recent years, shipping and ports industries are faced with enormous changes like globalization, market liberalization and borderless businesses. To cope with this competitive environment, a certain form of cooperation among ports is necessary to provide high quality of services and lower costs to establish their market power against shipping companies. The purpose of this study is to identify the motivation of the strategic alliances between ports and demonstrate the level of importance using Analytic Hierarchy Process(AHP). Among four motivations of the strategic alliances which are strategic motivation, economic motivation, operational motivation and marketing motivation, economic motivation is the most important factor for ports alliances than other factors. This is because economic motivation among strategic alliances allow ports in the same market to rationalize supply and demand, thus avoiding unnecessary over-supply and over-competition and also can reduce service costs by using comparative advantages of each partner which make costs cheaper.

• 한국IT서비스학회지
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• 제1권1호
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• pp.81-117
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• 2002

The generalization of Internet use has been spreaded all over the world and impacted company to introduce intranet and extranet for their operation which dealt with electronic commerce. For these reason, endeavor of implementation of web site system is promotioned and enhanced the possibility of adaptation range for the view of company. Dramatic competition which company faced with the use of internet and request from all over the world made company brought company to various and different type of level. It is necessary to develop website system with experty knowledge to satisfy customer needs. To deal with this situation, works from the level of government should proposed to spread whole country business which propelled through kyungnam mechanic industry information promotion center. With strategic proposal concerning district characteristics to adapt electronic commerce successfully, information promotion should performed. Support of government is needed continuously to realize infra of ASP composed of 4,877 mechanic industry company. It might be possible to deal with international rapid change with cooperation of company and government related department.

• Journal of Korea Trade
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• 제23권4호
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• pp.17-29
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• 2019

Purpose - This study examines the relationship between public-private partnerships and the performance of ports based on three factors: the quality of the port infrastructure, container throughput, and logistic performance in three Latin American countries, Mexico, Panama, and Brazil, for the period of 1994-2017. Design/methodology - The selected countries are top ranked in terms of container throughput in Latin America. The methodology employs secondary data from the World Bank (Quality of Port Infrastructure, Logistics Performance Index, and Private Participation in infrastructure database). Findings - Overall, the results revealed that the private investment of these countries varies significantly over the past couple decades. Panama, with the least public-private investment over the study period, performs better than Mexico and Brazil with regards to port quality infrastructure and container throughput. For ports in the selected countries to keep up with global competition, there is a need to enhance efficiency. Originality/value - Compared with ports in Asia, Latin American ports are lagging behind with respect to container throughput and efficiency. This study suggests greater collaboration from the private sector, academia, and other organizations, as well as a review of the regulatory framework to ensure better transparency and project allocation. Throwing more light on the public-private investment environment of Mexico, Brazil, and Panama, this study offers policy makers and regulators insightful information on port infrastructure.

• Journal of Smart Tourism
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• 제3권1호
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• pp.41-47
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• 2023

Tourism and hospitality have encountered significant changes in recent years as a result of the rapid development of information technology (IT). Customers now expect more expedient services and customized travel experiences, which has intensified competition among service providers. To meet these demands, businesses have adopted sophisticated IT applications such as ChatGPT, which enables real-time interaction with consumers and provides recommendations based on their preferences. This paper focuses on the AI support-prompt middleware system, which functions as a mediator between generative AI and human users, and discusses two operational rules associated with it. The first rule is the Information Processing Rule, which requires the middleware system to determine appropriate responses based on the context of the conversation using techniques for natural language processing. The second rule is the Information Presentation Rule, which requires the middleware system to choose an appropriate language style and conversational attitude based on the gravity of the topic or the conversational context. These rules are essential for guaranteeing that the middleware system can fathom user intent and respond appropriately in various conversational contexts. This study contributes to the planning and analysis of service design by deriving design rules for middleware systems to incorporate artificial intelligence into tourism services. By comprehending the operation of AI support-prompt middleware systems, service providers can design more effective and efficient AI-driven tourism services, thereby improving the customer experience and obtaining a market advantage.

• 한국항해항만학회지
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• 제48권2호
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• pp.78-87
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• 2024

To quantitatively assess the correlation between subsystems within a port cluster and the overall coordinated development of the port group, the current paper evaluates the coordinated development of port clusters. First, we construct an evaluation index system for the coupling and coordination of port clusters. Next, we introduce the contribution index of port subsystems, coupling degree, and coupling coordination degree functions to formulate a coupling coordination evaluation model for the port cluster. Finally, we use the Yangtze River Delta port cluster as a case study for validation, specifically using empirical data from 2012 to 2021. The findings reveal distinct phased characteristics in the coupling and coordination of port clusters in the Yangtze River Delta, marked by a notable transition from "maladjustment" to "coordination." Further, sustained high coupling values over a decade indicate a significant level of competition and cooperation among ports within the Yangtze River Delta port cluster. Over time, this competitive and collaborative dynamic has progressively evolved toward a more positive and structured direction. Lastly, it is expected that the evaluation model proposed in this paper can be extrapolated to other port clusters to gauge the extent of coordinated development, thereby facilitating horizontal comparisons and vertical analyses.