• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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• pp.105-109
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• 2005

폐기물매립장에서 발생하는 침출수의 확산정도를 정량적으로 추정하기 위해 매립장 주변에 설치되어 있는 2개 지하수공(BWM-1, BWM-2)에서 단공주입양수 추적자시험이 실시되었다. 브롬(Br-) 이온이 추적자로 이용되었으며, 추적자시험은 주입단계, 체이서단계 및 양수단계의 과정으로 실시되었다. 시험대상 구간은 지표면하 $20{\sim}24m$에 해당하는 파쇄암반층이며, 주입율과 양수율은 추적자시험 이전에 실시되어진 양수시험 자료에 의해 산정되었다. BWM-1 지하수공의 단공주입양수 추적자시험에 의해 추정된 종분산지수는 공극율이 0.01, 0.05, 0.1 및 0.5인 경우에 각각 9.50, 4.25, 3.00, 1.34cm 이다. 시험대수층의 공극율은 대략 $0.05{\sim}0.20$의 범위이며, 따라서 종분산지수는 $2{\sim}4cm$인 것으로 추정된다. BWM-2 지하수공의 단공주입양수 추적자시험에 의해 추정된 종분산지수는 공극율 0.01, 0.05, 0.1 및 0.5인 경우에 각각 3.32, 1.49, 1.05, 0.47cm 이다. 시험대수층의 공극율은 대략 $0.05{\sim}0.20$의 범위이며, 따라서 종분산지수는 $1{\sim}2cm$인 것으로 추정된다. 폐기물매립장에서 침출수가 유출할 경우, BWM-2 지하수공 주변의 파쇄암반층이 BWM-1 지하수공 주변의 파쇄암반층보다 침출수 확산이 2배 정도 빠르게 발생할 것으로 추정되었다.

• Journal of Advanced Marine Engineering and Technology
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• 제41권2호
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• pp.163-170
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• 2017

The International Convention for the Control and Management of Ships' Ballast Water and Sediments (hereafter "BWM Convention") will be enforced beginning on September 8, 2017. Even though the STCW Convention (International Convention on Standards of Training, Certification and Watchkeeping for Seafarers) and other international instruments require all ship personnel be qualified under certain competencies and standards, the International Maritime Organization (hereafter "IMO") has no unified requirements for training ship personnel on ballast water management. When the BWM Convention enters into force, all officers and crew on board ships should be intimately familiar with the guidelines and procedures outlined by the BWM Convention, regarding, among other topics, proper record keeping techniques and measures, the layout of the ballast control system, methods of ballast water exchange, and inspections by the port state control. To ensure that officers and crew members are adequately familiar, this paper proposes new competency requirements for ballast water management training and education to be added to the STCW Code. To support the introduction of these new competency requirements, this paper explores the evolution of the BWM Convention and examines how international regulations will be used to implement it.

• Journal of applied mathematics & informatics
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• 제42권2호
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• pp.257-281
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• 2024

In real life, a decision-maker can assign multiple values for pairwise comparison with a certain confidence level. Studies incorporating multi-choice parameters in multi-criteria decision-making methods are lacking in the literature. So, In this work, an extension of the Best-Worst Method (BWM) with multi-choice pairwise comparisons and multi-choice confidence parameters has been proposed. This work incorporates an extension to the original BWM with multi-choice uncertainty and confidence level. The BWM presumes the Decision-Maker to be fully confident about preference criteria vectors best to others & others to worst. In the proposed work, we consider uncertainty by giving decision-makers freedom to have multiple choices for preference comparison and having a corresponding confidence degree for each choice. This adds one more parameter corresponding to the degree of confidence of each choice to the already existing MCDM, i.e. multi-choice BWM and yields acceptable results similar to other studies. Also, the consistency ratio remained low within the acceptable range. Two real-life case studies are presented to validate our study on proposed models.

• Safety and Health at Work
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• 제13권3호
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• pp.326-335
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• 2022

Background: One of the important actions for enhancing human reliability in any industry is assessing human error probability (HEP). The HEART technique is a robust tool for calculating HEP in various industries. The traditional HEART has some weaknesses due to expert judgment. For these reasons, a hybrid model is presented in this study to integrate HEART with Best-Worst Method. Materials Method: In this study, the blasting process in an iron ore mine was investigated as a case study. The proposed HEART-BWM was used to increase the sensitivity of APOA calculation. Then the HEP was calculated using conventional HEART formula. A consistency ratio was calculated using BWM. Finally, for verification of the HEART-BWM, HEP calculation was done by traditional HEART and HEART-BWM. Results: In the view of determined HEPs, the results showed that the mean of HEP in the blasting of the iron ore process was 2.57E-01. Checking the full blast of all the holes after the blasting sub-task was the most dangerous task due to the highest HEP value, and it was found 9.646E-01. On the other side, obtaining a permit to receive and transport materials was the most reliable task, and the HEP was 8.54E-04. Conclusion: The results showed a good consistency for the proposed technique. Comparing the two techniques confirmed that the BWM makes the traditional HEART faster and more reliable by performing the basic comparisons.

• 수산해양교육연구
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• 제29권2호
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• pp.503-512
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• 2017

Over the past few years, as maritime trade and traffic were highly expanding, problem of invasive species via ballast water have been raised. In 1988, Canada and Australia had firstly experience that unexpected and hazardous species were observed on their own sea, they have issued the problem to MEPC under the IMO. At the end of many years of discussion, on the diplomatic conference in 13 Feb. 2004, "International Convention for the Control and Management of Ballast Water and Sediments of the Ship" was adopted. Requirements for entering into force of this Convention is that 30 countries ratify and world merchant marine fleet is more than 35% and BWM Convention will be effected after 12months from date satisfying conditions. With Finland ratifying the BWM Convention on 8 Sep. 2016, the fleet amounted to 35.1441% and ratification country became 52 countries. Therefore, after 12month, BWM Convention will be formally effected on 8 Sep. 2017. Ballast Water Treatment System is to be fitted in new ships as well as existing ships. Thus, there are concerns of ship owners to be suitably installed a variety typed BWTS in many kinds of vessels. As approaching for resolving these problems, engineering analysis was carried out research studies and detailed design to analyze to optimal installation space for retrofitting a BWTS using 3D Scanning method, targeting representative DWT 180K Bulk carrier of dry cargo vessels charged more 40% on worldwide vessel and mainly two type BWTS as electrolysis treatment type and ultra violet treatment type. Optimal design of 3D Scanning technology was applied to analyze four step process and the overall conclusion was described in this paper.

• 전자공학회논문지A
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• 제32A권1호
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• pp.26-35
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• 1995

Bo-Back-N ARQ is widely used in packet networks for error and flow control methanisms. This paper analyzes the network throughput under the go-back-N schem. Contrast to other analytic methods which assume independent frame losses or the first order Markov frame analytic methods which assume independent frame losses or the first order Markov frame losses concoptually, the proposed method takes into account the correlation between successive frame losses in a congested node. Computer simulation shows that our method generates more accurate performance results that independent assumption method. We apply the proposed method to analyze the performance of BWM in high speed networs. Our results show that BWM maintains the independence between traffic streams.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2017년도 추계학술발표회
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• pp.27-27
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• 2017

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2018년도 정기학술대회 발표논문집
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• pp.157-157
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• 2018

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2011년도 전기공동학술대회 논문집
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• pp.312-312
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• 2011

IMO BWM 협약이 발효가 되면 선박에 Ballast 수 처리 시스템 탑재 후 국가 간 항구 도착 시 각주관청의 Ballast water Discharge regulation D-2 만족 여부를 검사받게 된다. Ballast Water Sampling Device는 이러한 D-2 규정에서 요구하는 많은 양의 시료를 농축 후 신속히 분석하여 DATA의 신뢰성을 확보하기 위한 시료 전처리 장비로써, 그 활용성이 매우 클 것으로 판단된다. 본 연구 개발을 통해 개발된 Sampling Device의 특징은 많은 양의 시료를 효율적으로 농축하는 농축조와 농축 후 플랑크톤 네트에 잔류하는 미생물을 회수하는 린싱조로 구성되며, 다양한 실검증을 통해 최적의 조건을 확립하였다. 또한 모든 Sampling 공정이 자동화로 구현됨으로서 선박에 적합한 효율적인 Operating이 이루어질 수 있도록 구성하였다.

• 한국해양환경ㆍ에너지학회지
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• 제16권2호
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• pp.88-101
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• 2013

외래종의 유입을 막기 위해 '선박평형수와 침전물의 제어와 관리를 위한 국제협약'이 2004년에 체결되었고 이에 따라 다양한 선박평형수 관리장치가 개발되고 있다. 본 연구에서는 전기분해를 이용하여 선박평형수 내 해양생물 제거를 위한 장치로 개발된 AquaStar$^{TM}$ BWMS가 해양생태계에 미치는 영향을 파악하기 위하여 1차 생산자로서 규조류 Skeletonema costatum, 1차 소비자로서 윤충류 Brachionus plicatilis 및 포식자로서 어류(넙치) Paralichtys olivaceus를 이용하여 AquaStar$^{TM}$ BWMS의 배출수독성시험과 생성된 화학물질에 대한 환경위해성 평가를 수행하였다. 배출수독성시험결과 가장 민감한 생물은 S. costatum이었고 염분 20 psu 배출수에 노출되었을 때 NOEC 25.00%, LOEC 50.00% 및 72hr-$EC_{50}$이 69.97%였다. B. plicatilis와 P. olivaceus는 염분 20 psu 배출수에 노출되었을 때 NOEC 및 LOEC가 각각 50.00 및 100.00%였다. AquaStarTM BWMS에서 생성된 물질은 총 18개로, bromate, 7개의 volatile halogenated organic compounds, 7개의 halogenated acetic acids, 3개의 halogenated acetonitriles 및 chloropicrin이었다. 생성된 물질들의 지속성과 생물축적성을 보이는 화학물질은 없었으나, 물질의 생태독성을 평가하기에는 불확실성이 높았다. 그러나 MAMPEC 모델을 이용하여 생성된 18개 물질의 PEC는 $4.58{\times}10^{-4}{\sim}4.87{\mu}g\;L^{-1}$였고, PNEC는 $0.016{\sim}320.00{\mu}g\;L^{-1}$였으며, 18개 화확물질의 PEC/PNEC 비율은 1을 초과하지 않았다. 따라서 환경위해성평가결과는 AquaStar$^{TM}$ BWMS에 의하여 처리된 해수가 해양생태계에 수용 불가한 영향을 미치지 않는 것으로 나타났다. 또한 전기분해를 이용하는 BWMS의 배출수에 대한 S. costatum의 $EC_{50}$은 초기 TRO농도, HAAs의 농도 및 종류수와 양의 상관관계가 있었다.