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        검색결과 566

        81.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 다목적 관리기의 동력전달 시스템이 가혹한 작동환경에서 겪는 응력상황에 대한 분석을 유한요소해석을 수행함으로써, 기계요소의 안전성을 평가하는 한편, 개선 방안을 도출하고자 진행되었다. 엔진으로부터 작업기에 이르는 과정에 존재하는 동력전달 시스템은 엔진의 출력이 과도하게 인가될 경우 매우 높은 수준의 응력을 나타낼 우려가 있으며 따라서 이와 같은 가혹한 조건을 고려하기 위하여 동력전달 시스템의 출력축이 정지된 상황을 가정하여 시뮬레이션을 수행하였다. 볼클러치(Ball-clutch)와 PTO 조인트(Power take-off joint)에 대하여 응력해석을 수행한 결과 허용접촉응력 이상의 높은응력이 국부적으로 발생한다는 사실을 확인하였고, 이러한 문제를 해결하기 위하여 접촉부의 형상을 변경하여 추가적인 시뮬레이션을 수행하였다. 접촉부의 모서리에 일정 반경의 모깎기를 적용하거나 기계요소의 형상을 변화시켜 접촉면의 위치를 바꿈으로서 과도한 응력집중을 방지할 수 있음을 확인할 수 있었다. 이를 바탕으로 보다 우수한 내구성 및 신뢰성을 지닌 다목적 관리기를 개발할 수 있을 것으로 판단된다.
        4,000원
        82.
        2016.12 구독 인증기관 무료, 개인회원 유료
        Agrometeorological information used in agriculture field depends heavily on productivity in accordance with analysis and forecasting accuracy. In this study, we used necessary weather information for potato crops during the growing season and developed a decision support system to help farmers' management activities. The core of the solution is to utilize the real-time weather data observed in my field. By using application weather information in agricultural field rather than simple weather information transmission, we understood control effect through various pest information services. These ICT (Information & Communication Technologies) solutions in the field of weather-based agriculture provide appropriate intention information for growing crops, thus it is expected that effective control will reduce the risk of insect pests and reduce direct costs of farmers. In addition, it is expected that it will contribute not only to reduce soil pollution but also to safe food production by controlling indiscriminate use of pesticides properly.
        4,000원
        93.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper suggests a specific model that could efficiently improve the interaction and the interface between MES(Manufacturing Execution System) server and PDA terminal through RFID(Radio Frequency Identification) system and bar-code system in automative transmission shipment place of the finished assembly parts. The proposed model shows that the new method by RF-Tag system can more efficiently perform to reduce processing time and loading time for shipment, compared with the current approach by bar-code system. It is noted in case of the method by RF-Tag that the effects of proposed model are as follows; (a) While the shipping lead time per truck for carrying by the current method was 35 minutes, the shipping lead time by the new method was 15 minutes. (b) While the accuracy for carrying by the current method was 50%, the accuracy by the new method was 99%.
        4,000원
        94.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The train-centric control systems development has some distinct points in that a big size of government budget is in general expended in there and the development duration seems to be long. In addition, the changes are ever made continuously in the capability and operational requirements for Trains. Thus, the impact of the potential changes in the required operational capability on the development activities can induce some type of project risks [7]. As such, proper management of project risk has been one of crucial subjects in the train systems development. All these notes combined together make it the significance of the safety management process be raised further up in the train-centric control systems development. As such, the underlying safety management process should be capable of appropriately handling the potential risks that can be created due to the unexpected changes and the long-term development period. The process should also be complemented for the safety consideration of train-centric control systems, for instance, stop. To study these aspect is the objective of the paper. To do so, a step-by-step approach to analyzing the safety management process is first presented. Then, to enhance the process some necessary and useful activities are added in terms of risk and safety management. Then, to pursue some enhancement on the process, a set of necessary and useful activities are added in terms of risk and safety management. The resultant process is further analyzed and tailored using a design structure matrix method. The resultant process is applied in a train-centric control development as a case study.
        4,000원
        95.
        2016.09 구독 인증기관 무료, 개인회원 유료
        현행법은 폭력성⋅선정성 등으로부터의 청소 년을 보호하고 사행적인 게임물의 유통을 통제하 고자, 국내에 유통되는 게임물에 대해 사전 등급 분류를 받도록 하고 있다. 하지만 게임 환경의 변 화로 IPTV, 가상현실기기 등 기존의 분류 유형에 속하지 않는 새로운 플랫폼이 등장하자 기존의 법 률 체계를 적용하기 어려워졌다. 이에 2016년 5 월 29일 개정되어 2017년 1월 1일 시행되는 「게 임산업진흥에 관한 법률」은 게임물 자체등급분류 제도를 시행하기로 정했다. 이에 본 연구는 게임 물 자체등급분류제가 안착하기 위해 필요한 사후 관리시스템을 설계하는 데 기여하고자, 관련법들 과 유사한 사례를 검토한다. 먼저 게임물 등급분류 제도의 운영 현황을 살 피고, 이번 개정법에 의해 어떤 변화가 생기는지 정리한다. 정리된 내용을 바탕으로 개정법상 사후 관리시스템이 겪을 것으로 예상되는 문제를 진단한다. 그리고 그 문제를 해결하기 위해 두 종류의 유사한 경우를 살핀다. 첫 번째로 해외에서 게임물 자체등급분류제가 운영되는 양상을 알아본다. 미국의 ERSB, 유럽의 PEGI, 일본의 CERO가 운영되는 상황을 참고하 여, 개정법상 사후관리시스템이 원활히 운영되는 데 도움이 될 사항들을 검토한다. 다음으로 이미 방송사가 자체적으로 등급분류한 바를 사후적으 로 관리하고 있던 방송통신심위원회의 경우를 본 다. 방송심의규정의 근거와 구성을 살핀 후, 이에 근거해 운영되는 사후관리시스템에 대한 학계의 비판과 대안을 검토한다. 그리고 그중 게임물 사 후관리시스템 운영에 참고할 사항들을 정리한다. 이상의 연구를 통해 게임물 자체등급분류제 시 행 시 겪을 문제를 진단하고 대안을 제기한다. 또 그 대안이 유효하게 실행되기 위해 필요한 후속 연구도 제시한다
        5,400원
        96.
        2016.08 구독 인증기관·개인회원 무료
        현재 대다수의 국내 온실농장관리자는 온실내 작업자들의 농작업을 농가경영기록장(농장일지)을 이용하여 수기로 기록하고 있다. 이런 방법은 농작업 기록의 실수, 기록 후 분석을 위한 컴퓨터입력에 어려움, 작기별 비교분석의 어려움 등으로 농가경영기록장의 활용성이 매우 떨어지고 있다. 이에 본 연구에서는 NFC 기능을 이용하여 작업자들의 작업위치, 작업시간, 작업내용 등을 자동으로 기록하고 분석할 수 있는 스마트농작업관리시스템을 제안한다.
        97.
        2016.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : Long-life asphalt pavements are used widely in developed countries. In order to be able to devise an effective maintenance strategy for such pavements, in this study, we evaluated the performance of the long-life asphalt pavements constructed along the national highways in South Korea. Further, an economic evaluation of the long-life asphalt pavements was performed based on a life-cycle cost analysis. We aimed to devise a model for evaluating the performance of long-life asphalt pavements using the national highway pavement management system (PMS) database as well as for analyzing the economic feasibility of such pavements, in order to promote their use in South Korea. METHODS : The maintenance history and pavement performance data were obtained from the national highway PMS database. The pavement performances for a total of 292 sections of 10 lanes (5 northbound lanes and 5 eastbound lanes) of national highways were used in this study. Models to predict the performances of hot mix asphalt (HMA) and long-life asphalt pavements under two distinct traffic conditions were developed using a simple regression method. Further, the economic feasibility of long-life asphalt pavements was evaluated using the Korea Pavement Management System (KoPMS). RESULTS : We developed service-life prediction models based on the traffic volume and the equivalent of single-axle load and found that long-life asphalt pavements have service lives 50% longer than those of HMA pavements. Further, the results of the economic analysis showed that long-life asphalt pavements are superior in terms of various economic indexes, including user cost, delay cost, total cost, and user benefits, even though their maintenance cost is higher than that of HMA pavements. A comparison of the economic feasibilities of the various groups showed that group A is superior to HMA pavements in all aspects except in terms of the maintenance criterion (crack 20% or higher) as per the NPV index. However, the long-life asphalt pavements in group B were superior in terms of the maintenance criterion (crack 25% or higher) regardless of the economic feasibility. CONCLUSIONS: The service life of long-life asphalt pavements was found to be approximately 50% longer than that of HMA pavements, regardless of the traffic volume characteristics. The economic feasibility of long-life asphalt pavements was evaluated based on the KoPMS. The results of the economic analysis were the following: long-life asphalt pavements are exceptional in terms of almost all factors, such as user cost, delay cost, total cost, and user benefit; however, the exception is the maintenance cost. Further, the economic feasibility of the long-life asphalt pavements in group B was found to be better than that of the HMA pavements (crack 25% or higher).
        4,000원
        98.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Project management is a tool for smooth operation during a full cycle from the design to normal operation including the schedule, document, and budget management, and document management is an important work for big projects such as the JRTR (Jordan Research and Training Reactor). To manage the various large documents for a research reactor, a project management system was resolved, a project procedure manual was prepared, and a document control system was established. The ANSIM (Advanced Nuclear Safety Information Management) system consists of a document management folder, document container folder, project management folder, organization management folder, and EPC (Engineering, Procurement and Construction) document folder. First, the system composition is a computerized version of the Inter-office Correspondence (IOC), the Document Distribution for Agreement (DDA), Design Documents, and Project Manager Memorandum (PM Memo) works prepared for the research reactor design. Second, it reviews, distributes, and approves design documents in the system and approves those documents to register and supply them to the research reactor user. Third, it integrates the information of the document system-using organization and its members, as well as users’ rights regarding the ANSIM document system. Throughout these functions, the ANSIM system has been contributing to the vitalization of united research. Not only did the ANSIM system realize a design document input, data load, and search system and manage KAERI’s long-period experience and knowledge information properties using a management strategy, but in doing so, it also contributed to research activation and will actively help in the construction of other nuclear facilities and exports abroad.
        4,000원
        99.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Membrane structure is a system that is stabilized by maintaining a tensile state of the membrane material that originally cannot resist the bending or pressure. Also, it is a system that allows the whole membrane structure to bear external loads caused by wind or precipitation such as snow, rain and etc. Tension relaxation phenomenon can transpire to the tension that is introduced to the fabric over time, due to the innate characteristics of the membrane material. Thus, it is important to accurately understand the size of the membrane tension after the completion of the structures, for maintenance and management purposes. The authors have proposed the principle of theoretically and indirectly measuring the tension by vibrating the membrane surface with sound waves exposures against the surface, which is compartmentalized by a rectangular boundary, and by measuring the natural frequency of the membrane surface that selectively resonates. The authors of this paper measured the tension of preexisting membrane structure for its maintenance by using the developed portable measurement equipment. Through analyzing the measurement data, the authors review the points that should be improved and the technical method for the new maintenance system of membrane tension.
        4,000원
        100.
        2016.06 구독 인증기관·개인회원 무료
        도로 포장 및 교면 포장의 노후화로 인해 이에 대한 보수는 지속적으로 이루어지고 있고 매년 증가하고 있다. 도로 및 교량의 유지보수는 교통량이 많은 낮 시간보다는 교통량이 상대적으로 적은 야간에 주로 수행되고, 교통량이 다시 많아지는 시간 이전에 신속히 마무리하고 교통개방을 해야 하기 때문에 노무자 의 인력관리 및 안전관리를 체계적으로 수행하기가 쉽지 않다. 본 연구는 주로 야간에 주어진 시간 내에 신속히 작업을 수행해야하는 유지보수공정에 대하여 노무자 의 업무 및 안전을 체계적으로 관리하기 위해 실시간 위치정보 시스템을 구축하고, 현장에 시범 적용하여 그 가능성을 살펴보았다. 유지보수 현장에 총 8개의 고정식 노드를 설치하고 작업자의 안전모에 이동식 노드를 설치하여 현장에서 노무자의 작업 패턴을 충분히 확인할 수 있었다. 그리고 시스템 상에서 현장을 1m 격자로 구분하고 위험지역을 시스템 상에서 부여하여 노무자가 위험지역을 진입할 경우 이를 실시간 으로 확인하고 위험여부를 통보 가능함을 확인하였다.
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