• 한국강구조학회 논문집
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• 제20권1호
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• pp.9-20
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• 2008

강박스거더교 다이아프램부에 있어서 경제적이고 합리적인 설계가 요망되어 진다. 본 연구에서는 시공중인 4경간 강박스거더교에서 콘크리트 상판 타설 시와 차량재하 시에 응력을 측정한다. 측정 결과는 지점부 다이아프램부와 중앙부에서 응력분배를 연구하기 위하여 분석된다. 다이아프램부 수직보강재의 높이별 응력과 이와 같은 높이의 다이아프램부 응력을 정리하고, 이들 결과를 분석하여 적정 수직보강재 길이의 효율성을 판단한다. 또한 다이아프램부 3조의 수직보강재 각각의 응력을 분석하고, 콘크리트 경화 후 차량 재하 시와 시에 따른 응력비를 산출하여 다이아프램부 설계합리화 연구의 기본 자료로 수립하고자 한다.

• 한국산업융합학회 논문집
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• 제20권2호
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• pp.105-113
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• 2017

Recently the direct injection diesel engine is the most efficient one available for road vehicles, so this fundamental advantage suggests the compression injection diesel engine are a wise choice for future development efforts. The compression ignition diesel engine, with its bigger compression ratios if compared to the SI engine, offers a higher thermodynamic efficiency, also additionally the diesel engine with its less pumping losses due to the throttled intake charge as in a SI engine has higher fuel economy. But the largest obstacle to the success of this engine is meeting emission standards for Nitric oxides and particulate matter while maintain fuel consumption advantage over currently available engines. Thus its use should be largely promoted, however, diesel engine emits more Nitric oxides and particulate matter than other competing one. There has been a trade-off between PM and NOx, so efforts to reduce NOx have increased PM and vice versa, but trap change this situation and better possibility emerge for treating NOx emission with engine related means, such as injection timing, equivalence ratio, charge composition, and engine speed. The common rail direct injection system is able to adjust the fuel injection timing in a compression ignition engine, so this electronically controlled injection system can reduce the formation of NOx gas without increase in soot. In this study it is designed and used the engine test bed which is installed with turbocharge and intercooler. In addition to equipped using CRDI by controlling injection timing with mapping modulator, it has been tested and analyzed the engine performance, combustion characteristics, and exhaust emission as operating parameters.

• 스마트미디어저널
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• 제7권3호
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• pp.57-63
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• 2018

조직과 기업의 비즈니스 시스템의 규모가 커지면서 다양한 대량의 데이터들이 생성되는 비즈니스 환경의 변화와 데이터를 보다 스마트하게 처리하여 효율성을 높일 수 있는 방법으로 DataLake와 같이 단일 도메인 모델이 필요한 상황이다. 특히, 자원의 유한성과 공유 경제에 의한 물리적인 분할된 멀티 사이트의 데이터를 논리적인 단일 도메인 모델을 만드는 것은 컴퓨팅 자원의 효율적 운영 측면에서 매우 중요하다. 기존의 Data Lake 프레임워크의 장점을 기반으로 다양한 응용 영역의 멀티 사이트들을 통합 및 데이터 라이프 사이클을 관리하기 위한 Abyss Storage 기반 DataLake 프레임워크의 Connected Data Architecture 개념 (connected data architecture-concept)과 기능들을 정의하고, Connected Data Architecture 개념을 위한 인터페이스 설계 및 인터페이스(Interface) #2와 #3의 유효성 검증을 수행한다.

• 한국유통학회지:유통연구
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• 제1권1호
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• pp.41-63
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• 1996

In spite of economy has a critical cycle such as, production, distribution and consumption, we hardly concentrated our study to distributional system and behavior. Especially in Korea, Traditional idea had tried to ignore the people who work in this economic value at all. Manufacturers, other than retailers and wholesalers, had a belief that the manufacturing can control distributional channels forever. Unfortunately, technological and educational advances caused the quality equalization among developing and developed countries as well as among big and small manufacturers in their products. By this reason, economists are searching the economists dark continet' mentioned by Peter Drucker as a new source of wealth. According to a report by well-known economic research institute in Switzerland, Korea has classified in the lower level group in terms of international compatitive power. At the same time, business firms complain that they are suffering from lack of SOC and infrastructures. As an important mean to overcome the economic bottleneck, economists suggest in improve our distributional atmosphere. Basically, distributional study has two sub-fields as: commercial and physical distributions, Distributional system mainly concerns about to shorten the distances of time and space between production and consumption. The closer the distances, the higher efficiency can be achieved. Building distributional system will cost, but tile results will save social costs. Based on this idea, economists proposed several ways to cut the distances and to save costs, Naturally, they hope their beliefs can be adapted by business firms and governments. But frequently, their theories doesn't make any fruit. This paper has studied about the composition of joint transportational and distributional systems. And, even though there's no Marshall in tile real world at this point authors are trying to define the transportational and physical distributional costs, the most powerful factor that can impact to economic decision making.

• 자원리싸이클링
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• 제21권1호
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• pp.82-92
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• 2012

텅스텐카바이드는 금속절단 공구, 드릴의 날, 광산공구, 군사무기 재료, 화학원료, 촉매, 내마모성재료, 제트엔진 터빈 블레이드 등 다양한 용도로 사용된다. 요즘 경제적인 측면과 효율적인의 측면에서 텅스텐카바이드 재활용 기술이 넓게 연구되었다. 이 논문에서는 텅스텐카바이드 재활용 기술에 대하여 1969년부터 2011년까지 공개/등록된 미국, 일본, 유럽, 한국의 특허와 SCI급 논문을 조사하였다. 키워드를 이용하여 조사하였고 필터링 하여 특허와 논문을 수집하여 연도별, 국가별, 기관별, 기술별로 분석하였다.

• 한국항해항만학회지
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• 제32권6호
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• pp.473-479
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• 2008

최근 인터넷을 기반으로 하는 정보통신의 발전에 따라 경제 전반의 거래 패턴도 급속한 변화를 겪고 있다. 항만물류분야에서는 만성적인 고비용, 저효율의 물류관리 체계를 개선하기 위해 1990년 이후 온라인 서비스인 EDI를 구축하여 수출입관련 정보의 사전제공과 일괄처리를 통해 물류기업의 경쟁력을 강화하고 있다. 그러나 기존의 EDI는 VAN 환경에서 운영되어 고가의 통신장비 구입비용과 유지비용이 소요되며 설치기술이 복잡하여 즉각적인 처리 능력이 부족하다. 이런 문제점을 개선하고 불특정 다수간의 거래관계론 효율적으로 처리하기 위해 개방형 네트워크 환경에서 운영되는 웹기반의 EDI가 필요하다. 따라서 본 연구에서는 기반의 EDI 모델을 설계하되 기존의 EDI의 송신자가 특정 수신자에게 일방적으로 정보를 전달하는 푸시(push)방식을 개선시켜 다수의 수신자가 필요한 시점에 필요한 자료를 능동적으로 추출할 수 있는 풀(pull)방식의 새로운 모델을 제시하고자 한다.

• 한국태양에너지학회 논문집
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• 제37권4호
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• pp.35-47
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• 2017

Energy efficiency solutions are being pursued as a sustainable approach to reducing energy consumption and related gas emissions across various sectors of the economy. Vacuum Insulation Panel (VIP) is an energy efficient advanced insulation system that facilitates slim but high-performance insulation, based on a porous core material evacuated and encapsulated in a barrier envelope. Although VIP has been applied in buildings for over a decade, it wasn't until recently that efforts have been initiated to propose and adopt a global standard on characterization and testing of VIP. One of the issues regarding VIP is its durability and aging due to pressure and moisture dependent increase of the initial low thermal conductivity with time; more so in building applications. In this paper, the aging of commercially available VIP was investigated experimentally; thermal conductivity was tested in accordance with ISO 8302 standard (guarded hot box method) and long-term durability was estimated based on a non-linear pressure-humidity dependent equation based on study of IEA/ECBCS Annex 39, with the aim of assessing durability of VIP for use in buildings. The center-of-panel thermal conductivity after 25 years based on initial 90% fractile with a confidence level of 90 % for the thermal conductivity (${\lambda}90/90$) ranged from 0.00726-0.00814 (W/m K) for silica core VIP. Significant differences between manufacturer-provided data and measurements of thermal conductivity and internal pressure were observed.

• 농촌계획
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• 제25권1호
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• pp.21-38
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• 2019

Korean agricultural industry has weakened as demand for domestic agricultural products has declined due to accelerating market liberalization, aging and shrinking of rural population, and stagnating rural households' incomes. On the other hand, as the forth industrial revolution unfolds in earnest, tremendous changes are expected, and those changes won't be confined to certain industries but would shaken the world we know of entirely. Smart farm, which is one example of the fourth industrial revolution, is increasingly being recognized as a new growth engine for the future as smart farm and the science and technology behind it, not the size of arable land, will determine competitiveness of the agricultural industry and drive agricultural productivity and managerial efficiency. In consideration that John W. Kingdon's Multiple Streams Framework has recently been presented as an important theoretical model in the policy field, this study analyzed problem stream, policy stream, and political stream in the process of forming the smart farm policy, and looked into what role the government played as policy entrepreneur in policy window. The smart farm policy was put on policy agenda by the government and was approved when the government announced the Smart Farm Plan together with relevant ministries at the 5th Economy-Related Ministers' Meeting held in April 2018. This suggests that change of the government is the most critical factor in political stream, and explicitly indicates the importance of politics in formation of an agricultural policy. In addition, actual outcome of the policy and how policy alternatives that will enhance people's understanding will support it seem to be the key to success. It also shows that it is important that policy alternatives be determined based on sufficient discussion amongst stakeholders.

• 기술혁신학회지
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• 제21권4호
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• pp.1237-1267
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• 2018

한국은 1945년 광복 후 개발도상국의 단계를 거쳐 선진국의 대열에 이르기 까지 지속적인 경제성장을 가져왔지만, 한국보다 15년 뒤인 1960년에 독립한 나이지리아는 매우 풍부한 자연자원을 가지고 있음에도 불구하고 여전히 빈곤을 극복하지 못한 개발도상국의 위치에서 머물고 있다. 본 연구에서는 한국에서의 국가혁신체제와 경제개발계획이 경제발전에 끼친 영향을 고찰하여 개발도상국에 대한 시사점을 제공하고자 하였다. 검토 결과, 경제개발계획의 핵심적 성공요인은 구성요소간 유기적 커뮤니케이션, 지식 교환 및 국가혁신체제의 지속적 개선이었다. 특히 경제발전 관점에서 단계별 국가혁신체제는 매우 중요한 위치를 차지하고 있었다. 본 연구에서는 한국의 혁신체제관점에서의 발전경로를 기반으로 "multiple skipping"을 제안하고, 현재 나이지리아의 상황과 국가 수준의 지향점을 고려할 때 이를 통한 국가 발전을 계획하는 것이 보다 유용한 방법이 될 수 있을 것이라는 결론을 제시하였다.

• 대한조선학회논문집
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• 제56권1호
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• pp.58-65
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• 2019

The stability, reliability and efficiency of a smart ship are important issues as the interest in an autonomous ship has recently been high. An automatic collision avoidance system is an essential function of an autonomous ship. This system detects the possibility of collision and automatically takes avoidance actions in consideration of economy and safety. In order to construct an automatic collision avoidance system using reinforcement learning, in this work, the sequential decision problem of ship collision is mathematically formulated through a Markov Decision Process (MDP). A reinforcement learning environment is constructed based on the ship maneuvering equations, and then the three key components (state, action, and reward) of MDP are defined. The state uses parameters of the relationship between own-ship and target-ship, the action is the vertical distance away from the target course, and the reward is defined as a function considering safety and economics. In order to solve the sequential decision problem, the Deep Deterministic Policy Gradient (DDPG) algorithm which can express continuous action space and search an optimal action policy is utilized. The collision avoidance system is then tested assuming the $90^{\circ}$intersection encounter situation and yields a satisfactory result.