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        검색결과 447

        421.
        2005.06 KCI 등재 서비스 종료(열람 제한)
        해상 준설선을 이용한 항로의 준설시공 과정에서 중요한 점은 작업구역의 공간적 축소로 여유통항수역의 제공과 수면하의 위험물 배제로 안전항행을 제공하는 것이 기본이다. 이를 위해서는 준설선의 이동과 고정을 위한 보조장비의 적극적인 활용과 함께 부대 장비의 실시간 위치확인, 실시간 준설수심 확인 및 작업정보 등을 통합적인 정보로 제공하여 준설 작업의 자동화를 꾀해야 한다. 그런데, 본 연구에서 스퍼드 제어시스템을 비치한 준설선은 준설 시공시 준설구역 내 준설점 위치로 이동을 스퍼드로 하고 스퍼드는 자동제어 기술을 적용하여 준설선의 능동적 이동에 의한 준설시공을 행하여 최소의 작업공간을 점유하게 되므로 항행하는 타 선박의 안전한 통과를 허용하면서 준설공사를 중단 없이 시공할 수 있다. 또한, 스퍼드 활용 항로준설시스템은 스퍼드의 거동괘적은 물론 전자해도와 함께 작업심도 자료를 동시에 제공하므로 신속한 작업성과까지도 제시할 수 있다는 점에서 기존의 관리시스템과는 비교가 된다. 시스템 평가를 위한 부산항에서의 시험시공결과 일일 작업 시 기존의 앵카시스템을 이용한 작업시간의 2배정도를 실제 투입할 수 있었으며, 준설시공 요건별 비교에서도 준비시간을 38% 절감할 수 있었고 준비작업에 필요한 작업인력을 1인 줄일 수 있는 것으로 나타났다.
        422.
        2005.02 KCI 등재 서비스 종료(열람 제한)
        본 연구의 목적은 컨테이너터미널의 생산성 향상을 위한 새로운 운영시스템 기술 도입에 따른 기대효과를 분석하는 것이다. 컨테이너터미널의 운영시스템을 종합관제시스템 운영시스템, 계획시스템, 정보기술 등의 크게 4가지 기능으로 분류하며, 총 19가지 신기술 대안을 선정하였다 선정된 운영시스템 기술대안에 대해서 현장 전문가를 대상으로 한 설문조사 및 면담조사를 통하여 기술대안별 중요도와 생산성 향상지수를 추정하고 생산성 향상 평가모형을 수립하였다. 또한, 생산성 향상 평가모형을 이용하여 운영시스템 기술 도입에 따른 대안별 기대 생산성을 산출해 보았다 따라서, 새로운 운영시스템의 도입시 기대 생산성을 분석하고자 할 경우에 유용하게 사용 가능할 것으로 본다.
        424.
        2004.10 KCI 등재 서비스 종료(열람 제한)
        이 연구에서는, 인간(해기사)의 두 귀에 주목한 머리전달함수(HRTF)를 이용하여, 기적음과 관련된 해양사고를 분석-평가하기 위한 시뮬레이션 시스템(3D-LSS)을 개발하였다. 해양사고당시 상황을 분석해서 가청화 모델을 구축하고, 3차원음 생성방법과 평가방법을 제시하였다. 개발한 시스템은 GUI 방식의 그래픽과 3차원 음향으로 해양사고 당시의 상황을 묘사하고, 시뮬레이션 할 수 있도록 구성하였다. 3D-LSS을 이용하여, 해양사고 중에서 기적음 청취여부를 판단하지 못했던 6가지 사건을 대상으로 실시하였다. 5명의 평가자에 의한 심리음향 평가결과, 6가지 사건을 시각적 청각적으로 명확하게 평가할 수 있었기 때문에 3D-LSS의 해양사고 심판보조 장치로서의 활용가능성을 확인할 수 있었다.
        425.
        2004.02 KCI 등재 서비스 종료(열람 제한)
        본 연구의 목적은 항해하고 있는 선박의 항해안전성을 평가할 수 있는 탑재형 내항성능 평가시스템 개발을 위한 각 내항성능 평가요소에 대한 상대위험도 D/B를 구축하고자 한다. 탑재형 내항성능 평가시스템은, 선박에 설치하여 선체 운동에 의해 발생하는 상하방향의 가속도를 측정하는 상하가속도 측정기와, 선박의 항해 안전성을 평가하는 종합내항성능지표를 계산하는 컴퓨터 및 종합내항성능지표를 토대로 내항성능 평가도 및 경과도를 모니터 화상 처리 공간상에 표시되도록 구성되어진다. 본 논문에서는 이중에서 선박의 변환 평가치 및 한계 평가치를 사용하여 파랑 중 선박의 종합적인 항해안전성을 평가하는 종합내향성능지표를 계산하는데 필요한 내항성능 평가 프로그램의 알고리즘에서 중요한 역할을 담당하는 내항성능 평가요소의 상대위험도 D/B를 구축하는 방법을 제시한다. 그리고 모델 선박을 사용하여 구축된 상대위험도 함수가 주어진 화물 적재상태, 해상상태, 파향 및 선속에 대한 해당 조건을 토대로 내항성능 평가 프로그램에서 정확하게 구현될 수 있는지를 검토하였다.
        426.
        2003.09 KCI 등재 서비스 종료(열람 제한)
        When the city water was heated for the optimum use of unused energy, the energy flows and losses were calculated and evaluated to improve the value of heated water systems at dwelling side. To obtain this purpose, It was simulated on heat flows under two conditions like with heat pumps or not and calculated the energy savings. Furthermore, recycling water system was suggested for enhancing the value of heated water system. From this results, the energy flows without heat pumps showed that it was 3-4 percents of heat losses from pipes, 62 percents of energy savings from hot water uses and 34 percents of unutilized heat. When the heated water system adopt the recycling water system at dwelling side, it was improved 12 percents of total energy savings.
        427.
        2002.12 KCI 등재 서비스 종료(열람 제한)
        2-체널 링-코어 프럭스-게이트 콤파스(Two-Channel Ring-Core Flux-Gate Compass; TCRC FG-Compass)의 성능평가 시스템 설계와 구현방법 및, 다항회귀 모형 기반의 평가 절차와 방법을 기술했다. 성능평가 시스템은 스템모터 구동 유닛과, 방위정보 전송 유닛, 다항회귀식에 의한 평가 프로그램 등으로 구성하였다. 성능평가 실험결과, TCRC FG-Compass는 잔차가 2˚인 반면, 기존의 FG-Compass는 잔차가 4˚임을 나타냈다. 따라서 성능이 향상된 새로운 FG-Compass 설계가 가능함을 확인하였다. 또한, 자동으로 잔차를 추정하고 보정할 수 있는 설계론에 관해서도 논의하였다.
        428.
        2002.02 KCI 등재 서비스 종료(열람 제한)
        위험도 평가기준을 발전함수를 고려하여 단일저수지에 적용한 박명기 등(2001)의 혼합정수계획법 모형을 다중저수지군 운영에 적합하도록 개선하였다. 본 모형중의 축차선형계획기법(SLP)은 목적함수중 수력발전함수의 선형화를 위하여 적용되었으며, 저수지 방류량의 합리적인 월별 방류배분을 위하여 수력발전량에 대한 가중치를 발전시간 수준별로 적용하도록 정식화요소에 반영하였다. 개선된 모형은 한강수계 5개 저수지군에 시험적용 하였으며, 수계내 연계운영을 위한 복합저
        429.
        2001.12 KCI 등재 서비스 종료(열람 제한)
        In the present study, irregular disturbances to ship dynamics is proposed, where irregular disturbances implying irregular wave and the fluctuating component of wind for the evaluation of automatic steering system of ship in following seas. Prediction method based on the principle of linear superposition. Irregular wave disturbances in following seas is calculated by frequency variation method. The mathematical model of each element of an automatic steering system is derived, which takes account of a few non-linear mechanisms. PD(Proportional-Derivative) controller and low-pass filter with a weather adjustment are adopted to modelling the characteristics of an autopilot. Performance index is introduced from the viewpoint of energy saving, which derived from the concept of energy loss on ship propulsion. Finally, the present methods are applied to two typical types of ship ; an ore carrier and a fishing boat. The various effects of control constants of autopilot on propulsive energy loss are investigated
        430.
        2001.09 KCI 등재 서비스 종료(열람 제한)
        This study aims to develop the information service system of integrated seakeeping performance for seagoing vessels. It has been successful in developing the intended system which has made possible to provide the following functions and capabilities: ⦁ immediate computation of the dynamic motions of a ship against the present and future weather conditions; ⦁ evaluation of the integrated seakeeping performance of a ship on a real time basis and providing the navigators with the seakeeping informations on the spot enabling them to take the most appropriate countermeasures; and ⦁ supporting the navigators in the selection of a safe sailing route by providing the integrateseakeeping performance.
        431.
        2001.06 KCI 등재 서비스 종료(열람 제한)
        The fish species collected in the Keumho River basin are 42 species 31 genera elonging to 15 Families. This report was investigated for the evaluation of water quality in the Keumho River system which is a tributary of Nakdong River in Korea on september in 1999. The fishes collected were 42 species, 31 genera belonging to 15 Families. The dominant species were 5 species; Zacco platypus, Zacco temmincki, Squalidus chankaensis tsuchigae, Moroco oxycephalus, Squalidus gracilis majimae, and 8 species; Hemibarbus longirostris, Pseudogobio esocinus, Culter brevicauda, Cobitis rotundicaudata, Pseudobagrus fulvidraco, Pungitius sinensis kaibarae, Monopterus albus, Clanna argus were rare species. The relationship among the GPI, EC and BOD by the organic pollutants were over 0.9. The group pollution index(GPI) was lowest at St. 1(0.85) and highest at St. 5(2.33). The water quality of the Keumho river divided into 3 parts; the water of upper reaches in river(St. 1) was 1st class(oligotrophic condition), middle parts(St. 2, 3, 4) were 3rd class( a -mesosaprobic condition) and lower part(St. 5) was 4th class(Polysaprobic condition) as the source of tap water, respectively. And the tributary which are the Sinryeong Stream(St. 6), the Sincheon Stream(St. 7) and the Donghwa Stream(St. 9) in Keumho river were 2nd class as the source of tap water. The results in this study was represented same patterns as the result by the use of indicator species like as algae and invertebrates for the discrimination of water quality. So, some freshwater fish species can be use applicant for the discrimination of water quality.
        432.
        2001.04 KCI 등재 서비스 종료(열람 제한)
        A macroeconomic minimodel was simulated to analyze the effect of global exchange on the Korea's economy. The simulation results illustrate some of the consequences of public policy and some insight into current world problems. All computer simulation runs made under various conditions suggest that the Korea's system in the near future may be strongly influenced by the favorable availability of outside resources, while the national power and assets may be declined by indigenous environmental stock depletion. The borrowed capital allows the temporary money stock to increase and the national assets to grow faster and a little higher, as using up the environmental resources more quickly. Later, when the debt is paid off, the foreign exchange holdings may not go so high. For the environmentally sound and sustainable development, over 75% of total economic production should be invested to the natural resource management. Therefore, the economic structure of Korea should be transferred from the present industrial structure to social-economic structure based on ecological-recycling concept.
        433.
        2001.03 KCI 등재 서비스 종료(열람 제한)
        In an effort to effectively manage and evaluate a water environment at a small watershed, a decision support system for a water environment management and evaluation has been developed. This paper described the overall features and functions of the water environment management and evaluation systems (WEMES) for environmental management, conservation, and evaluation at a small watershed. WEMES consisted of fore subsystems: data, simulation model, evaluation model, and user interface. Each of the systems were briefly described. And special features like simulation and evaluation models were also introduced.
        434.
        2000.06 KCI 등재 서비스 종료(열람 제한)
        From a ship's safe operation point of view, it is very important to estimate the navigational safety in a seaway. The seakeeping performance can be defined as the ability of a ship to go to sea, and to accomplish its missions successfully and safely even in adverse environmental conditions. There are several factors presently adopted for evaluating seakeeping performance. But a hardware of the system considering all these factors has not been developed since some of them can not be measured by sensors. In this paper, a synthetic method of evaluating navigational safety is developed by measuring the vertical and lateral acceleration. An experiment by using real measuring carried out on board the T/S 'HANNARA' The equipment was measured every 4 hours for more than 30 minutes the acceleration by accelerometer, analyzed its acceleration values and calculated navigational dangerousness. As the results of this on board experiment, the system is carried conviction to be useful as evaluating seakeeping performance.
        435.
        2000.03 서비스 종료(열람 제한)
        For composing the structure model of national maritime power system by system structural modeling, in this study, the 50 basic factors are selected by survey of the extensive and through literatures on maritime, sea, maritime power and sea power. And the basic factors are classified into 36 component factors by cluster method. The 9 attributes are extracted by the application of the principle component analysis method, one of the factor analysis method in system engineering, to component factors. In this study, we define the attributes composing the national maritime power system by integrating the result of this study and existed our studies relating to this topic. Which are showed in Table 2. and we show the structure model of national maritime power system in Fig. 3. In Table 2, the 9 attributes are as follows : the fundamental power of maritime, shipping and port power, naval power, fishing power, shipbuilding power, the power of ocean research and development, dependency on seaborne trade, the protection power of ocean environment and the will and inclination of govemment. Also, in the case of evaluating this system, we conform the importance of considering the interactions among the attributes which have strong interactions in structure model of national maritime power system.
        437.
        1999.02 KCI 등재 서비스 종료(열람 제한)
        This study, a sub-one of comprehensive research works titled under "Rural Resources Evaluation System", tried to verify utility/applicability of the developed model system through the case study works on 3 sample villages, Backya, Uyan and Suyu, representing the lowland, upland and seashore villages respectively. From the various surveying and collecting works including the official/statistical data collection, map analysis, in-situ investigation, field survey and written material review, the original data set were obtained and manipulated into final input data for resources grading. After then, by the automatized calculation procedure of "Rural Resources Evaluation System", score results for resources evaluation were finally produced with the total maximum score being 1,000. Through comparing works among score results of 3 case villages and between score results and areal characteristics of each case village, the applicability of the system developed in this study was well confirmed.
        438.
        1998.10 KCI 등재 서비스 종료(열람 제한)
        This study examined the carbon dioxide (CO_2) pollution inside vehicles under low ventilation condition and evaluated the Air Quality System (AQS) for in-vehicle air quality using two techniques. The low ventilation condition is not recommended in order to keep oxygen-rich condition inside vehicles. Under the low ventilation condition, the in-vehicle CO_2 concentrations exceeded 1,000 ppm, the air quality guidelines in the United States, Western Europe, and Japan, indicating more oxygen deficiency inside vehicles. On the contrary, with the AQS-on condition, the in-vehicle CO_2 concentrations were less than 1,000 ppm for most of the driving time, indicating that the AQS could solve the problem of CO_2 accumulation inside vehicles under the low ventilation condition. The AQS test conducted by comparing carbon monoxide (CO) and volatile organic compound (VOC) concentrations inside two vehicles indicated that the AQS effectively decreased the in-vehicle concentrations by 21 to 36%, as compared to medium ventilation condition with the windows closed, the vent opened, and air conditioning on. In addition, The AQS test conducted by comparing the interior and exterior concentrations indicated that the AQS effectively decreased the in-vehicle concentrations by 18 to 31%, as compared to medium ventilation condition.
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