• Journal of Advanced Marine Engineering and Technology
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• 제38권3호
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• pp.240-245
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• 2014

환경오염에 대한 심각성이 대두되면서 선박부문의 온실가스 배출에 관한 연구가 전 세계적으로 활발하게 진행되고 있다. 이에 반하여 국내는 아직 기초 연구수준에 그치고 있다. 본 연구에는 실습선 한바다호를 이용하여 운항 중 발생하는 온실가스를 정량적으로 조사하였고, 연료소모량과 육상전기 사용량을 바탕으로 실습선이 배출하는 온실가스를 산정하였다. 2012년 1년 동안의 실제 운항데이터에서 연료소모량과 육상전기 사용량을 기본으로 Tier 1 방법을 이용하여 온실가스를 산정하였다. 이를 통하여 선박 총톤수 1톤을 운항 유지하는데 배출되는 배출 가스량과 실습생 1명을 1년 실습시키는데 발생하는 가스량을 분석하였다. 향후 선박에서 발생하는 오염물질의 인벤토리를 지속적으로 관리하여 강화되고 있는 국제 규제에 대비해야 할 것으로 사료된다.

• 한국CDE학회논문집
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• 제15권5호
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• pp.362-374
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• 2010

Product Lifecycle Management (PLM) is an integrated business approach to manage the creation and distribution of product information throughout the product development process. From the product perspective, PLM encompasses a holistic approach to product development and product information management. It supports the integrated product information in conjunction with the efficient product structures and BOM (Bill Of Material), user interfaces, proper functions, design processes and enterprise integration. Therefore, PLM should not only satisfy required functions as an enterprise software but also offer a systematic method for the efficient application from the initial stage of its development. Recently, many shipyards have been considering the PLM as a strategic solution to get the efficient management of product information such as 3-D models, BOM, drawings, documents, and the other product data. Though many studies on PLM are performed, most of them are performed in a function-based approach adequate for mass productive assembly industries. It could not help having limitations on applying the proper PLM system to the shipbuilding business since the requirements of shipbuilding PLM are too diverse and huge to design the architecture. This study presents the PLM framework which effectively reflects the diverse requirements of shipbuilding PLM. In order to get the macroscopic architecture of shipbuilding PLM, authors suggest the four-tier architecture model which considers the various requirements collected from shipyards. Entities of ship design data are modeled BOM in terms of product structure and hierarchical class diagram. Applicable functions of shipbuilding PLM are also investigated by analysis of issues of ship design. Finally, by reflecting the design process of shipbuilding, To-Be ship design procedure cooperated with the suggested PLM framework has been summarized.

• 한국지반공학회논문집
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• 제21권7호
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• pp.21-29
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• 2005

본 논문에서는 압축성이 큰 지반 위에 시공되는 지오그리드 보강 계단형 블록식 보강토 옹벽의 거동 특성에 관한 내용을 다루었다. 대상옹벽으로는 2단으로 시공되는 높이 lOrn의 블록식 보강토 옹벽을 고려하였으며 압축성이 큰 지반위에 시공되는 경우를 고려하였다. 본 연구는 검증된 유한요소해석 모델을 사용하여 수행되었으며 기초지반의 침하가 옹벽의 변위 및 보강재 유발 인장력에 미치는 영향을 집중적으로 다루었다. 연구결과 시공중 발생하는 기초지반의 과다 침하는 옹벽의 변위 뿐 아니라 보강재 유발 인장력 또한 현저히 증가시켜 내·외적 안정성에 지대한 영향을 미치는 것으로 나타났다. 본 논문에서는 연구결과와 아울러 실무적 관점에서의 고려사항 을 기술하였다.

• 한국컴퓨터정보학회논문지
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• 제7권3호
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• pp.23-29
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• 2002

지리정보체계(GIS)의 자료처리 설계는 분석절차와 더불어 효율적인 방법이 요구되는 과정이다. 본 연구는 3계층 기반의 객체지향기법을 적용한 도형 사용자 접속 환경의 원도우용 체계로서 조건에 따른 도로의 노선선정을 제시할 수 있도록 사용과 유지관리를 손쉽게 하였다. 자료계층은 지오미디어와 응용계층과의 상호 자료 교환, 추출 및 보존을 위한 클래스를 담당하였다. 응용계층에는 시ㆍ종점간의 노선선정에 필요한 제반조건을 고려하여 노선선정 알고리즘을 적용하였으며, 자료 운용, 도로조건, 영향권, 클로소이드 및 계층분석과정 등을 모듈식으로 추가하여 새로운 조건별에 따라 비교노선을 선정할 수 있도록 하였다. 사용자 계층에는 응용계층에 취득된 자료들을 표현할 수 있도록 하였다. 따라서 3계층 기반구조를 이용하여 GIS의 자료 처리의 설계구현에 그 효율성을 제시할 수 있었다.

• 수산해양기술연구
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• 제47권4호
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• pp.369-389
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• 2011

Changes in ecosystem risks were evaluated using the ecosystem-based fisheries assessment (EBFA) approach of Zhang et al. (2009, 2010) and the comprehensive ecosystem-based fisheries management (EBFM) plan was made for the southern sea of Korea in this study. The risk assessment of the southern sea ecosystem was conducted by establishing ecosystem management objectives and by estimating risk scores (RS) for indicators. To conduct this analysis a number of indicators and their reference points for assessing these risk scores were developed in this study. The number of indicators in the risk analysis was 28 for the quantitative tier 1 analysis and 30 for the qualitative tier 2 analysis. The objective risk index (ORI), species risk index (SRI) and fisheries risk index (FRI) were calculated from the risk scores. Comparing the past (1988) and the current (2008) status of fisheries resources, management implications were discussed. The fishery risk index (FRI) of large purse seine fishery in the southern sea of Korea decreased substantially from 0.972 in 1988 to 0.883 in 2008, and improvement in the management of fisheries operated in the southern sea of Korea.

• 농업과학연구
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• 제50권3호
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• pp.383-394
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• 2023

In Korea, the U.S. Tier-4 Final emission standards have been applied to agricultural machinery since 2015. This study was conducted to analyze the emission characteristics of agricultural tractors during plow tillage operations using PEMS (portable emissions measurement systems). The tractor working speed was set as M2 (5.95 km/h) and M3 (7.60 km/h), which was the most used gear stage during plow tillage operation. An engine idling test was conducted before the plow tillage operation was conducted because the level of emissions differed depending on the temperature of the engine (cold and hot states). The estimated level of emissions for the regular area (660 m²), which was the typical area of cultivation, was based on an implement width of 2.15 m and distance from the work area of 2.2 m. As a result, average emission of CO (carbon monoxide), THC (total hydrocarbons), NOx (nitric oxides), and PM (particulate matter) were approximately 6.17×10-2, 3.36×10^-4, 2.01×10^-4, and 6.85×10^-6 g/s, respectively. Based on the regular area, the total emission of CO, THC, NOx, and PM was 2.62, 3.76×10^-2, 1.63, and 2.59×10^-4 g, respectively. The results of total emission during plow tillage were compared to Tier 4 emission regulation limits. Tier 4 emission regulation limits means maximum value of the emission per consumption power (g/kWh), calculated as ratio of the emission and consumption power. Therefore, the total emission was converted to the emission per power using the rated power of the tractor. The emission per power was found to be satisfied below Tier 4 emission regulation limits for each emission gas. It is necessary to measure data by applying various test modes in the future and utilize them to calculate emission because the emission depends on various variables such as measurement environment and test mode.

• 한국임상약학회지
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• 제25권3호
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• pp.159-165
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• 2015

Objective: Polypharmacy is one of the main causes of inappropriate medication use, adverse drug-related events and cost. It aimed to investigate the status of polypharmacy and potentially inappropriate medication (PIM), the factors affecting polypharmacy and cost in elderly outpatients. Method: A pharmacy claim data were retrospectively analyzed with elderly patients prescriptions at a pharmacy located near a top tier general hospital. The numbers of medications per person, prevalence of polypharmacy and PIM according to the 2012 Beers criteria and Korea PIM list, medication cost and the factors affecting polypharmacy were investigated. Results: Forty-six percentages of the elderly outpatients received polypharmacy and over 21% of them had medications listed in Beers or Korean PIM. In multiregressional analysis, we found that age, gender and insurance types were affective factors of polypharmacy. (p < 0.001, 0.047, 0.009, respectively). The cost of polypharmacy with PIM in elderly outpatients was increased with age. Various approaches of interventions would be further required.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권2호
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• pp.628-649
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• 2017

Security and resource-saving are both demands of the fifth generation (5G) wireless networks. In this paper, we study the secrecy spectrum efficiency (SSE) and secrecy energy efficiency (SEE) of a K-tier massive multiple-input multiple-output (MIMO) enabled heterogeneous cellular network (HetNet), in which artificial noise (AN) are employed for secrecy enhancement. Assuming (i) independent Poisson point process model for the locations of base stations (BSs) of each tier as well as that of eavesdroppers, (ii) zero-forcing precoding at the macrocell BSs (MBSs), and (iii) maximum average received power-based cell selection, the tractable lower bound expressions for SSE and SEE of massive MIMO enabled HetNets are derived. Then, the influences on secrecy oriented spectrum and energy efficiency performance caused by the power allocation for AN, transmit antenna number, number of users served by each MBS, and eavesdropper density are analyzed respectively. Moreover, the analysis accuracy is verified by Monte Carlo simulations.

• 대한산업공학회지
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• 제39권6호
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• pp.587-598
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• 2013

In Korea military (KM), various military supplies are distributed to individual military units via three different multi-tier supply networks owned and operated by army, navy, and air force, respectively. Under the current supply networks, the chances for the occurrence of delayed supply, undersupply, and oversupply increase, and supply redundancy also can become a problem. Thus, KM is now trying to improve its current multi-tier supply networks by constructing logistics consolidation centers. Private companies operate logistics consolidation centers to effectively manage various types of inventories before delivering them to final customers. In this paper, we newly propose a mathematical model for building the optimized military supply network considering adopting the military logistics consolidation centers. Based on the real situation of KM, the proposed model was validated in terms of its feasibility, and it seems that the outcome (the location of the military logistics consolidation centers) of the proposed model can be one of the good alternatives for KM.

• 한국언어정보학회지:언어와정보
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• 제11권1호
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• pp.1-23
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• 2007

This study aims to research into the meaning of Korean particle 'ka' and 'nun' inductively by examining the correspondences of those particles and English articles on the Korean-English parallel corpus. The correspondences were checked in three ways: semantically, syntactically and pragmatically. This study found that when the semantic or syntactic tier is not salient, the pragmatic tier is activated and particles are selected according to the pragmatic elements such as the amount of information or the change of topic. However, if the meaning of the particles is salient or if there is any syntactic motive, particles are selected in accordance with the semantic or syntactic elements. Former studies which focused on one of those three tiers cannot properly explain such correspondences on the Korean-English parallel corpus. This study shows that semantic, syntactic and pragmatic tiers hierarchically affect the selection of a particle and that the selection process is also related to speaker's intention. This dimensional analysis of particles is expected to contribute to theoretical studies and applied studies like Korean language education as well.