• 산업경영시스템학회지
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• 제32권3호
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• pp.10-19
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• 2009

Wireless LAN systems have been widely implemented for supporting the wireless internet services especially in the hotspot areas such as hospitals, homes, conference rooms, and so on. Compared with wired LAN systems, wireless LAN systems have the advantages of the users' mobility support and low implementation and maintenance costs. IEEE 802.11 wireless LAN systems employ the backoff algorithm to avoid contentions among STAs when two or more STAs attempt to transmit their data frames simultaneously. The MAC efficiency can be improved if the CW values are adaptively changed according to the channel state of IEEE 802.11 wireless LANs. In this paper, a dynamic contention window control algorithm is proposed using the genetic algorithm to improve the MAC throughput of IEEE 802.11 wireless LANs.

• 한국항해항만학회지
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• 제38권2호
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• pp.177-184
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• 2014

Recently, brand equity is paid much attention in various industries. However, container liner shipping companies are still unfamiliar with this concept, and also the brand equity model has not been tested yet in shipping context. This study, therefore, aims to measure the relative importance of brand equity factors of container liner shipping companies by employing AHP (Analytic Hierarchy Process). This study concludes that perceived quality, in particular cost-related service quality, is the most influential factor of brand equity, while weak support is found for brand association. In addition to this, group comparisons were conducted between shipping companies, freight forwarders and academics. The results will be useful as they firstly define brand equity and its role in shipping context, highlighting the significance of brand management to container liner shipping firms. This evaluation is not an end in itself, but will eventually be utilised as a tool to build competitive advantage which cannot be easily imitated by competitors.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권12호
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• pp.6169-6187
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• 2017

With the fast growth of mobile services, Mobile Cloud Computing(MCC) has gained a great deal of attention from researchers in the academic and industrial field. User authentication and privacy are significant issues in MCC environment. Recently, Tsai and Lo proposed a privacy-aware authentication scheme for distributed MCC services, which claimed to support mutual authentication and user anonymity. However, Irshad et.al. pointed out this scheme cannot achieve desired security goals and improved it. Unfortunately, this paper shall show that security features of Irshad et.al.'s scheme are achieved at the price of multiple time-consuming operations, such as three bilinear pairing operations, one map-to-point hash function operation, etc. Besides, it still suffers from two minor design flaws, including incapability of achieving three-factor security and no user revocation and re-registration. To address these issues, an enhanced and provably secure authentication scheme for distributed MCC services will be designed in this work. The proposed scheme can meet all desirable security requirements and is able to resist against various kinds of attacks. Moreover, compared with previously proposed schemes, the proposed scheme provides more security features while achieving lower computation and communication costs.

• 유통과학연구
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• 제17권12호
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• pp.43-54
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• 2019

Purpose: Marine transportation companies must improve service quality to secure competitive advantage and continuous relationships with customers. This study explores the value and necessity of service quality in the industry by empirically identifying the factor that would have the largest effect on the improvement of service quality, also examining whether such improvement may actually influence continuous relationships. Research design, data and methodology: Based on an online survey with those in the Korean marine transportation industry, this study conducted statistical analyses using structural equation modeling. Based on relevant previous studies, the current study constructed a total of 55 survey questions. Finally, 281 questionnaires were collected, but 68 were excluded owing to invalid responses. Results: Information service attribute had the largest effect on service quality, whereas communication did not demonstrate a significant influence. In addition, distribution and information services exerted a positive effect on service satisfaction through service quality, and finally influenced relationship continuity. Conclusions: The results shows that marine logistics service quality strategies which were centered on time or local factors, should be considered in terms of the development of innovative services. In particular the improvement of information service systems and strategies in changed business environment.

• 수산해양기술연구
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• 제53권4호
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• pp.456-470
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• 2017

We propose some countermeasures needed to cope with fortifying international regulations for fisheries subsidies. The government should rigorously select the recipients of fisheries subsidies to ensure that they are not engaged in ineffective projects by resorting to subsidies. On the other hand, the government should make the individual applicant's application for the subsidies easier by exempting them from the submission of a burdensome feasibility report. As for the strengthening regulatory international movements against the fisheries subsidies, we can consider the following countermeasures. One is not to designate and provide prohibitive subsidies in such a way that violates international norms. The other one is to reform the domestic fisheries subsidies system in Korea with the following points considered. It should be considered that fisheries subsidies, which can be categorized as the actionable subsidies, should not be granted to the items that can be exported but to the items that can be used for domestic consumption or processing. In the case of non-actionable subsidies, the subsidies are mainly allowed for promotion of public-sector research and development, regional development, and adaptation to new environmental regulations. Thus, the non-actionable subsidies should be designated in the consideration of the allowances for these activities.

• 디지털융복합연구
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• 제12권3호
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• pp.69-77
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• 2014

스마트 TV는 일반 TV와 달리 방송시청이라는 목적 외에 다양한 기능을 가지고 있기 때문에 구매자들은 제품 선정시 복잡한 의사결정 문제에 직면하게 된다. 제조사별로 다양한 모델이 출시되고 있기 때문에 이들 제품들 간 비교 평가를 요구하고 있다. 본 연구는 소비자들이 스마트 TV를 구입할 때 고려되어야 하는 선정기준을 도출하고, 계층적 분석과정(AHP)을 사용한 일련의 의사결정 방법을 제안한다. 이용자테스트 방법을 제안하며 Expert Choice를 사용하여 구현 예를 보인다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.142-143
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• 2017

무기체계에 첨단기술이 접목되고 연구개발에 많은 비용이 듦으로써 소요군은 수명주기 전 단계에서 무기체계의 높은 신뢰도를 요구하고 있다. 하지만 국방 무기체계의 신뢰도에 대한 연구는 관심부족 또는 자료수집의 제한으로 실증적인 연구가 제한되고 있다. 본 연구에서는 무기체계 운용자인 함정, 작전 및 정비지원 부대(작전사, 군수사, 정비창, 업체)들을 직접 방문하여 수집한 경험을 바탕으로 야전운용제원 수집 프로세스를 제안하였으며, 이를 활용하여 해성 유도탄 발사체계의 운용 MTBF를 도출하여 개발 시 목표값과 비교 분석하였다.

• 한국국방경영분석학회지
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• 제35권2호
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• pp.63-76
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• 2009

IT와 과학 기술의 비약적인 발전으로 미래전의 양상도 바뀌고 있으며 이에 따라 효과적인 군수지원의 중요성이 부각되고 있다. 본 연구에서는 최근 부각되고 있는 통합 물류창고 중 자동창고를 중심으로 S/R machine의 운영문제를 Travel Time에 기반을 둔 수리적 분석과 AutoMod를 이용한 시뮬레이션으로 수리적 분석의 타당성을 검증하였다. 이에 따라 자동창고의 S/R machine의 개선된 정주위치 고려와 재고회전 빈도에 따른 운용성능을 분석할 수 있었다.

• 한국정보통신학회논문지
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• 제10권11호
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• pp.1927-1933
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• 2006

본 논문에서는 이네비게이션(E-Navigation)의 기반이 될 수 있는 정보 네트워크의 구현방안을 제시한다. 정보통신 기술을 이용하여 E-Navigation 정보네트워크의 기반이 되는 네트워크 체제를 구성하고, 해상교통지원시스템을 정비함과 동시에 종합적인 항만 정보네트워크를 구축한다. 그리고 항만관련 종사자에게 선박간, 선박과 육상간 무선 네트워크 이용을 권고하여 그 효율성을 확대할 것이다. E-Navigation을 위한 정보네트워크의 구축은 항만의 물류흐름과 교통안전을 위하여 초고속 무선인터넷 인프라를 구축하는 것으로서, 해상에서의 적용이 더욱 효과적인 무선 정보네트워크 인프라를 항만 내에 도입하는 것 다. 인터넷이 가지 고 있는 무한한 잠재성, 응용성, 공유성을 이용하므로 해상 교통 흐름 및 교통안전에 획기적 인 변화를 가져올 수 있을 것이다.

• 한국군사과학기술학회지
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• 제19권1호
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• pp.76-83
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• 2016

State-of-the-art design S/W and other 3D systems are used for design and development of weapon system. It is possible to detect problems of design through 3D or VR(Virtual Reality) in advance, and then reduce the development cost by finding solutions before prototype production. Therefore, we can increase efficiency for supportability of weapon system. In this study, we first propose a design verification procedure. Then we verify design of weapon system, underwater guided weapon, as a case study. Finally, we suggest alternatives for underwater guided weapon under development with DMS(Digital Maintenance System) and ICIDO from the point of view of ILS(Integrated Logistics Support). Developed S/W, DMS, draws maintenance procedures for components. Commercial S/W, ICIDO, verifies cable maintainability.