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        검색결과 10

        1.
        2021.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper presents a real-time, false-pick filter based on deep learning to reduce false alarms of an onsite Earthquake Early Warning (EEW) system. Most onsite EEW systems use P-wave to predict S-wave. Therefore, it is essential to properly distinguish P-waves from noises or other seismic phases to avoid false alarms. To reduce false-picks causing false alarms, this study made the EEWNet Part 1 'False-Pick Filter' model based on Convolutional Neural Network (CNN). Specifically, it modified the Pick_FP (Lomax et al.) to generate input data such as the amplitude, velocity, and displacement of three components from 2 seconds ahead and 2 seconds after the P-wave arrival following one-second time steps. This model extracts log-mel power spectrum features from this input data, then classifies P-waves and others using these features. The dataset consisted of 3,189,583 samples: 81,394 samples from event data (727 events in the Korean Peninsula, 103 teleseismic events, and 1,734 events in Taiwan) and 3,108,189 samples from continuous data (recorded by seismic stations in South Korea for 27 months from 2018 to 2020). This model was trained with 1,826,357 samples through balancing, then tested on continuous data samples of the year 2019, filtering more than 99% of strong false-picks that could trigger false alarms. This model was developed as a module for USGS Earthworm and is written in C language to operate with minimal computing resources.
        4,200원
        4.
        2015.02 서비스 종료(열람 제한)
        본 연구는 현재 소방방재청에서 운영하고 있는 지진재해대응시스템에 지반 물성을 고려한 지반재해위험도를 탑재하기 위한 방법론 및 활용방안에 대한 연구이다. 지진재해대응시스템은 기상청에서 수신된 지진정보로 진도분포도를 작성 후 이를 바탕으로 각 행정동 단위의 건축물, 인명, 파이프라인, 구조물의 피해추정을 산출한다. 하지만 이들 피해추정은 지반의 토층 두께만을 고려한 지반증폭률로 산출된 지반최대가속도로 추정된 값으로 지진에 의한 지반의 물성 변화에 따른 피해추정까지 고려된다면 보다 높은 신뢰성을 갖출 수 있다. 지반의 물성은 시추자료를 토대로 입도분포, 표준관입시험(SPT-N치)등의 정보를 수집하여 이를 바탕으로 지반의 물성 변화 즉, 지반 액상화 평가를 하여 지반재해위험도 지도를 작성한다. 지반재해위험도 지도는 지진시나리오별로 시추자료의 좌표점을 기준으로 액상화가능성지수(LPI, Liquefaction Potential Index)로 나타난다. 하지만 시추자료는 대부분 도심지 및 도로, 터널 등 토목공사를 위한 기초자료를 수집하기 위한 시추자료들로 그 외 산간지역이나 농업지역등은 시추자료가 존재하지 않아 시범지역을 모두 커버할 수 없다. 그렇기 때문에 자료가 없는 부분은 보간기법을 적용하여 수치적 해석방법을 수행해야 한다. 수치적 해석을 통해 작성된 지반재해위험도 지도를 현재의 지진재해대응시스템에 탑재함으로써 지진발생시 지반의 물성 변화에 따른 2차 피해 추정의 기초자료로 활용 할 수 있다.
        5.
        2012.02 서비스 종료(열람 제한)
        한반도는 지리적으로 주변국보다는 지진재해의 빈도가 비교적 적은 지역으로 인식되어 있지만, 지진 발생 빈도수가 점차 증가함에 따라 지진재난으로부터 국민의 생명과 재산을 보호하기 위한 방재대책이 필요한 시대적인 요구에 직면해 있다. 이를 대비한 시스템으로 현재 소방방재청에서는 지진재해대응시스템을 구축·운영 중이다. 이번 연구에서는 기존 지진재해대응시스템에 추가적으로 적용할 수 있는 지진재해로 인한 사회 경제적 피해예측 모델 적용을 위한 지진재해대응시스템의 방법론과 관련된 연구를 진행하고자 하였다. 피해예측 모델을 적용하기 위해서는 먼저 지진피해평가기법을 완성하여야 하는데, 이를 위해 지진기록 뿐만 아니라 지진피해에 대한 다양한 현장조사 기록 및 기초 자료들이 필요하다. 하지만 국내에는 이와 같은 기초자료서 활용가능 기본 데이터베이스의 구축이 자료의 양은 적지 않으나, 오래된 자료가 많고 이번 연구에 적용가능의 활용도가 떨어지는 경우가 많다. 지진재해대응시스템에 응용하기 위해 기초자료로서 사용되는 지진가속도자료 또는 토양층 정보, 전단파 속도자료 데이터베이스 정보 등을 선별하여, 최대지반가속도 또는 스펙트럴 가속도 등을 구하는 경험식에 적용하고자 하였다. 또한, 현재 소방방재청에서 진행 중인 지진가속도계측자료통합관리시스템의 산출물인 가속도 정보를 향후에 지진재해대응시스템의 기초자료로서 사용할 수 있는 방안을 설계단계에서 고려하는 연구를 진행 중이다. 이를 통해 해당분야의 적용연구에 대한 선행연구로 이용될 수 있을 것이다.
        6.
        1998 서비스 종료(열람 제한)
        The evaluation of port competition could be applied to determining the selection of a calling port. A few fundemental attributes of port competition were adapted by the 'brian storming'method. The criteria used for evaluating a port's competitiveness were as follows : efficiency of port operations, competitive power of each port's industry, economic activity of the hinderland associated with each port and capability of globalization. The weight of each criterion was 30%, 40%, 20% & 10%, respectively. And the most important factors that were considered in choosing each of the above criteria were profitability, port information system, cargo volume & inducement of foreign capital. The results of this study seemed to suggest that factors which influence port competition varied according to port circumstances, such as computer and communication systems and access to the global trade within the World Trade Organization.
        7.
        1993.06 서비스 종료(열람 제한)
        The rapid progress of the intermodal freight transportation in recent years has induced fierce competition among the adjacent hub ports for container transport. This brings increased attention to the evaluation of the port competitive ability. But it is not easy to evaluate the port competitive ability because this belongs to ill-defined system which is composed of ambiguous interacting attributes. Paying attention to this point, this paper deals the competitive ability of container port in Far-East Asia by fuzzy integral evaluation which is adequate to interacting ambiguous attribute problem. For this, the proposed fuzzy evaluation algorithm is applied to the real problem, based on the factors such as cargo volumes, costs, services, infrastructure and geographical sites These are extracted from the precedent study of port competitive ability, etc. The results show that the port evaluation factors come in following order ; services, costs, infrastructure, geographical sites and cargo volumes. There are some interactions(interaction coefficient, λ=-0.664 between evaluation attributes. The port competitive ability comes in following order : Singapore, Hongkong, Kobe, Kaoshiung and Busan. According to the sensitivity analysis, the rank between Busan and Kaoshiung changes when λ=0.7. From the analysis of the results, we confirmed that the proposed fuzzy evaluation algorithm is very effective in the complex-fuzzy problem which is composed of hierarchical structure with interacting attributes.
        8.
        1993.06 서비스 종료(열람 제한)
        In complex decision making such as ill-defined system, one of the main problem is how to treat ambiguous aspect of the decision making. According to the complexity and ambiguity of the objective systems, many types of evaluation attributes are necessary for the rational decision and the relationship among the attributes become complex and fuzzy. Fuzzy integral is very effective to evalute the complex system with interaction between attributes but how to save the evaluation efforts in the decision making process of grading the membership of the objects or alternative is the problem to be tackled. Because the more object there are to evaluate, the number of decisions to made increase exponentially. Therefore, this paper aimes to propose a new evaluation algorithm based on fuzzy integral which can save the evaluator's efforts in decision making process. The proposed algorithm is constructed as follows : First, compose the fuzzy measure by introducing AHP(Analytical Hierachy Process) & mutual interaction coefficient. Second, generate fuzzy measure value of monotone family set for calculating the fuzzy integral. The effectiveness of the proposed algorithm is investigated through the example and sensitivity of interaction coefficient is illustrated.
        9.
        1985.10 KCI 등재 서비스 종료(열람 제한)
        The transportation productivity is the throughput of utility per locations of resources and is able to be brought forth by using transportation mode. Therefore, Oil energy is necessary for using the transportation mode that is mainly consisted of four parts trucks, railroad, ship and aircraft, and Oil quantity used for such modes is not respectively same. Noticing Such a Point, the purpsoe of this paper is to reaserch the transportation mode of convertable cargoes and to minimize energy consumption quantity by adopting such a mode. We must ttend to Energy-Intensity, Transportation, Distance and cargo quantity for selecting the transport mode to energy consumption and the minimization of transportation energy consumption is concluded in the next LP Problem. As above mentioned, we can find the solution of Xij by the LP when Xij is transportation cargo per routes, and fullfil the minimization of Energy Consumption.
        10.
        1985.06 KCI 등재 서비스 종료(열람 제한)
        Sea casulties involving tankers, compared with those incurred by other type of vessels, have become particularly threatening to port State in terms of environmental as well as property damages. As a result, most of developed countries including the U.S.A. and Japan have shown a strong interest in implementing the policy of the Port State Control more rigorously in an attempt to protect themselves from irreparable damages caused by sea casualties involving large vessels. In this paper, the problems associated with the implementation of the Port State Control are analysed and then following recommendations and suggestions are made: ⅰ) The flag nation is urged to improve the quality of personnel associated with the operation of a ship. ⅱ) A closer cooperation between developing nations operating vessels and developed nations adopting the Port State Control is required for a successful implementation of this policy. ⅲ) Port states are advised to give a special attention to vessels carrying hazardous cargoes.