• 해양환경안전학회지
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• 제19권6호
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• pp.658-665
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• 2013

본 연구에서는 국제해사기구(IMO)의 뜨거운 관심분야로 부상되고 있는 선박기인 입자상물질(PM)과 오염물질 배출에 관하여 한국해양대학교 실습선 한바다호를 이용하여 계측하였다. 특히, PM은 TEM 그리드를 이용해 채취하고 전자현미경으로 구조를 파악하였으며, NOx, $CO_2$, CO 등의 배기가스는 연소가스분석기(PG-250A, HORIBA)를 이용해 측정하였다. 본 연구의 결과는 다음과 같다. 1) 선박이 항구에서 출항할 때, Bunker Change로 인한 PM 배출량은 최대 30 % 정도 차이가 있었다. 2) 정속 운항을 하면서 Bunker-A에서 L.R.F.O(3 %)로 변경할 때 측정한 PM 배출량은 $1.34mg/m^3$, L.R.F.O(3 %)로 고정해 측정한 PM 배출량은 $1.19mg/m^3$, L.R.F.O(3 %)만 사용하며 주기관 회전수를 20 % 증가시키면서 계측한 PM 배출량은 $1.40mg/m^3$ 이었다. 또한, 저질유(L.R.F.O(3 %))로 변경시 CO 농도는 약 16 % 증가하는데 비해 RPM을 20 % 상승시킨 경우에는 152 % 이상 급격한 증가를 보였다. 이러한 결과로부터 배기가스 배출의 증가는 연료유종의 영향도 있으나, RPM의 변화에 민감하다는 것을 알 수 있었다. 3) TEM 그리드로 채취한 PM은 약 $4{\sim}10{\mu}m$ 정도의 다양한 입경을 가지는 다공질 응집체 형상의 구조인 것으로 확인하였다.

• 해양환경안전학회지
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• 제18권6호
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• pp.584-590
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• 2012

본 연구에서는 고정자와 회전자에 의해 발생하는 전단력(Shearing force)을 이용한 선박용 연료유 균질기(Homogenizer) 개발에 관한 연구를 수행하였다. 균질기의 균질화 및 미립화 정도에 대한 성능을 조사하기 위하여 IFO 380 cSt Bunker-C 시료에 전처리(Pre-treatment)를 시행하였다. 전처리한 시료의 슬러지(Sludge) 저감 효과를 확인하기 위하여 유청정기(Oil purifier)를 이용하였다. 실험결과 균질기로 전처리한 시료에서 슬러지양이 약 13 % 감소하는 것을 확인하였다. 또한, 전처리 후 유청정한 시료를 실제 보일러 시스템에서 연소시켜 CO가 감소하는 연소특성 경향을 확인하였다. 이와 같은 결과를 통해 개발된 선박용 연료유 균질기를 실선에 적용할 경우 연료비 및 운항비용 절감 효과가 있을 것으로 판단된다.

• 대한조선학회논문집
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• 제53권4호
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• pp.336-342
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• 2016

H-CSR(Harmonized Common Structural Rules) integrating CSR-BC(Common Structural Rules for Bulk Carriers) and CSR-OT(Common Structural Rules for Double Hull Oil Tankers) came into effect in July of 2015, so that bulk carrier and double hull oil tanker should comply with this rules. So far, several studies for trend analysis of requirements of structure scantling based on H-CSR have been carried out briskly. However, those studies are rare to apply H-CSR in actual structural design of ships, especially bulk carriers. In this study, an automated system for compartment arrangement is used to search the design case that minimizes still water bending moment(S.W.B.M) in 38k bulk carrier designed by Far East Ship Design & Engineering Co. Ltd. Also, various structural design cases are considered by changing arrangement of structural members to reduce ship weight. The SeaTrust-Hullscan software developed by Korean Register is used to perform structural design of ships based on mother ship and proper design cases are selected by user. The DSA(Direct Strength Analysis) is performed to evaluate structural safety for the yielding and buckling analysis by using MSC Nastran software. The effect of weight reduction is verified by comparison of ship weight between mother ship and the selected design cases.

• International Journal of Naval Architecture and Ocean Engineering
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• 제6권3호
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• pp.507-528
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• 2014

In the ship and offshore structure design, age-related problems such as corrosion damage, local denting, and fatigue damage are important factors to be considered in building a reliable structure as they have a significant influence on the residual structural capacity. In shipping, corrosion addition methods are widely adopted in structural design to prevent structural capacity degradation. The present study focuses on the historical trend of corrosion addition rules for ship structural design and investigates their effects on the ultimate strength performance such as hull girder and stiffened panel of double hull oil tankers. Three types of rules based on corrosion addition models, namely historic corrosion rules (pre-CSR), Common Structural Rules (CSR), and harmonised Common Structural Rules (CSR-H) are considered and compared with two other corrosion models namely UGS model, suggested by the Union of Greek Shipowners (UGS), and Time-Dependent Corrosion Wastage Model (TDCWM). To identify the general trend in the effects of corrosion damage on the ultimate longitudinal strength performance, the corrosion addition rules are applied to four representative sizes of double hull oil tankers namely Panamax, Aframax, Suezmax, and VLCC. The results are helpful in understanding the trend of corrosion additions for tanker structures.

• Journal of Advanced Marine Engineering and Technology
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• 제40권3호
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• pp.185-190
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• 2016

선박이 고출력화, 초대형화 됨에 따라 대형저속 2행정 엔진을 탑재한 선박에서 축계배치의 잘못에 기인하는 주기관 선미측 베어링과, 선미관 후부 베어링의 손상이 증가하는 경향이 있다. 또한 고출력화에 의한 추진축의 강성은 증가한 반면에 선체는 고장력 후판을 사용하므로 이전의 선체보다 훨씬 더 쉽게 변형하는 실정이다. 이는 기존의 선박보다 더욱 정교한 축계배치가 요구됨을 의미한다. 본 연구에서는 열팽창 효과, 감도지수를 이용한 중간축 베어링의 최적위치 선정 및 베어링의 강성을 고려하여, 베어링의 하중 분석 및 영향 계수를 분석함으로서 축계 배치가 이론적으로 최적이 되는 것을 검토하였다. 이를 위하여 축계 배치 계산시 대형 엔진 제조사의 엔진 거치기준을 참조하고, 한국선급 및 DnV 선급의 축계 배치 프로그램을 이용하여 검토하고 그 신뢰성을 검증하였다.

• 대한인간공학회지
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• 제36권5호
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• pp.485-498
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• 2017

Objective: This study aims to survey and compare three systemic accident investigation techniques of Accimap, STAMP and FRAM, based on the application studies of the Sewol ferry accident. Background: Traditional accident investigation methods such as domino models, FTA, etc. work well for losses caused by physical component failures or actions of human in relatively simple systems, but are unable to depict mechanisms generating errors and violations in the current complex socio-technical systems. For better understanding the structure and behavior of the socio-technical systems, systemic techniques have been developed and used. Method: This study was mainly based on survey of literatures through surfing webpages of ScienceDirect and Google, and ergonomics relevant journals. The key words of Sewol, Sewol ferry, Sewol ferry accident, etc. were used in the survey. Results: Three systemic accident investigation methods included similar actors in the Sewol ferry accident including government, Ministry of Ocean and Fisheries, Korean Coast Guard, Korean Register of Shipping, Korea Shipping Association, Chonghaejin Marine Company, crew members. The methods graphically represented each level's failures or performance variabilities of relevant functions and relationships between them. It was shown that the systemic methods consider the entire system, ranging from the environment in which the accident occurred, to the role of government in shaping the system of work. Each method has its own comparative pros and cons, but the Accimap has advantages in terms of time of analysis, data required, model complexity and degree of comprehensiveness. Conclusion: This study reviewed and compared three systemic accident investigation methods, which showed that there are systemic characteristics and pros and cons in the methods. Application: The results would be used as a guideline when selecting accident investigation methods.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제11권7호
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• pp.283-290
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• 2022

블록체인 기술은 거래를 투명하게 관리함으로써 중앙통제 없이 신뢰 가능한 P2P 거래를 가능하게 한다. 최근에는 금전적 가치를 지닌 선하증권(Bill of Lading, B/L서류)의 무결성을 확보하기 위해 블록체인을 적용한 연구가 진행되고 있다. 본 논문에서는 사용성 개선을 위한 블록체인 기반의 선하증권 시스템을 제안한다. 수출자는 선사로부터 발급 받은 선하증권을 블록체인에 저장하고, 은행에서 이를 조회하여 신용장 거래를 수행한다. 수입자는 선하증권 서류의 지문이 담긴 QR코드(Quick Response code)로 신원증명을 완료한 뒤 화물을 인도 받게 된다. 수출자는 우편으로 보낼 시간과 비용을 절약하고, 물품의 보안을 강화할 수 있다는 점에서 큰 효과를 거둘 수 있다. 수입자의 경우 선적 서류가 블록체인 네트워크에 등록되자 마자 서류를 열람할 수 있고, 신뢰를 바탕으로 거래를 수행할 수 있다는 이점을 갖는다. 뿐만 아니라 은행에서는 선적서류에 대한 검증을 더욱 신속하게 수행할 수 있다.

• 수산해양교육연구
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• 제28권6호
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• pp.1602-1613
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• 2016

Since Ballast Water Management Convention has been adopted, Ballast Water Management Convention is not effected yet. This convention will only enter into force 12 months after its ratification by 30 states, collectively representing 35% of world merchant shipping tonnnage. Morocco, Indonesia and Ghana have ratified this convention during last 29th IMO Assembly meeting which was held in November 2015. In 2016, Belgium, Fiji, Saint Lucia and Peru have become the latest countries to ratify the convention. As of now, 51 states and 34.87% combined merchant fleets are being calculated. BWM convention will be applied to not only new ships but also, existing ships after it is effected. Thus, existing vessel will be retrofitted a Ballast Water Treatment System according to D-2 Requirement until first IOPP nenewal survey after date of entry into force of the convention. Currently, about 65 BWTSs certified by Administration will be reported to IMO, even type of BWTSs is very various. Thus, a risk of each BWTS can be existed, and this existed risk can be also effected to ship's crew safety and protection of ship's own property. Therefore, we have evaluated a risk assessment for an existing vessel retrofitting an ultra violet type Ballast Water Treatment System which is mostly developed in the world. And we described the procedure of selecting a sample vessel, consequently, bulk carrier is selected because this vessel kind is mostly charged in the world. Especially, DWT 175K size is selected. Risk Assessment is using a HAZID and HAZOP method, evaluation method is referred to IMO Document "Considerated test of the Guidelines for Formal Safety Assessment (FSA) for use in the IMO rule-marking process(MSC/Circ.1203-MEPC/Circ.392)". The Risk Assessment Section is decided to 3 Nodes, Consequently, total risks have evaluated 51 items.

• 수산해양교육연구
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• 제29권3호
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• pp.665-676
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• 2017

Over the past several years, sea trade have increased traffic by ships which highlighted a problem of unwanted species invading the surrounding seas through ship's ballast water discharge. Maritime trade volume has continuously increased worldwide and the problem still exists. The respective countries are spending billions of dollars in an effort to clean up the contamination and prevent pollution. As part of an effort to solve marine environmental problem, BWM(Ballast Water Management) convention was adopted at a diplomatic conference on Feb. 13 2004. In order to comply harmoniously this convention by each country. This convention will be effective after 12 months from the date which 30 countries ratified accounting for more than 35% of the world merchant shipping volume. On Sep. 8 2016, Finland ratified this convention and effective condition was satisfied as 52 states and world merchant vessel fleet 35.1441%. Thus, after Sep. 8 2017, all existing vessels shall be equipped with BWTS(Ballast Water Treatment System) in accordance with D-2 Regulation, which physically handles ballast water from ballast water exchange system(D-1 Regulation). In this study, we analyzed in detail the optimal design method using the Risk Analysis and Evaluation technique which is mainly used in the manufacturing factory or the risky work site comparing with the traditional design concept method applying various criteria. The Risk Assessment Method is a series of processes for finding the Risk Factors in the design process, analyzing a probility of the accident and size of the accident and then quantifying the Risk Incidence and finally taking measures. In this study, this method was carried out for Electrolysis treatment type on DWT 180K Bulk Carrier using "HAZOP Study" method among various methods. In the Electrolysis type, 63 hazardous elements were identified.

• 대한조선학회지
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• 제25권2호
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• pp.19-30
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• 1988

Sectional added masses of an elastic beam vibrating vertically on the free surface in higher harmonic modes are evaluated. Hydrodynamic interactions between neighboring sections, which strip theory ignores, are considered for modal wave lengths of the order of magnitude of cross-sectional dimensions of the body. An approximate solution of modified Helmholtz equation which becomes a singular perturbation problem at small wave lengths is secured to get an analytic expression for added masses attending higher harmonic modes. As a bound of the present theory, the modified Helmholtz equation is solved for the long flat plate vibrating at high frequency on the water surface without any limitations on modal frequency. Finally, extensive series of numerical calculations are carried out for ship-like forms. It is found that when modal wave length is comparable to or shorter than a typical cross-sectional dimension of a body, sectional interaction effects are large which result in considerable reductions in added masses. For a fuller section, the ratio of added mass reduction is greater. In the limit of vanishing sectional area, the added masses approach to that of flat plate of equal beam. It is shown that the added mass distribution for a Legendre modal from can be determined form the present theory and that the results agree with the extensive three-dimensional determination of Vorus and Hilarides.