• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.6 no.3
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• pp.383-391
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• 2016

Ballast water provides stability and manoeuvrability to a ship. Foreign harmful aquatic organisms, which were transferred by ballast water, cause disturbing ecosystem. In order to minimize transference of foreign harmful aquatic organisms, IMO(International Maritime Organization) adopted the International Convention for the Control and Management of Ship's Ballast Water and Sediments in 2004. If the convention take effect, a port authority might need to check that ballast water is properly disposed of. In this paper, we propose a method of counting harmful aquatic organisms in ballast water thorough image processing. We extracted three samples from the ballast water that had been collected at Busan port in Korea. Then we made three grey-scale images from each sample as experimental data. We made a comparison between the proposed method and CellProfiler which is a well known cell-counting program based on image processing. Setting of CellProfiler is empirically chosen from the result of cell count by an expert. After finding a proper threshold for each image at which the result is similar to that of CellProfiler, we used the average value as the final threshold. Our experimental results showed that the proposed method is simple but about ten times faster than CellProfiler without loss of the output quality.

• Journal of the Korean Society for Marine Environment & Energy
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• v.8 no.4
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• pp.174-178
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• 2005

Destruction of marine ecology system induced by the bal last water discharged from ships is one of the most serious problem among the various ship associated environmental impacts. International Maritime Organization (IMO) has actively dealt with this problem for a long time and is going to start to activate very strong international treatment for preventing ocean from such serious environmental impact. Various technologies of ballast water treatment are now being developed all over the world. In this paper, recent trend of existing ballast water treatment technologies is investigated in detail. Furthermore, in order to apply electrolysis technology to ballast wale r treatment, its basic principle is reviewed theoretically and its feasibility is checked through some in-situ experiments. Quite good results are shown in the experiments enough to confirm its applicability in ballast water treatment.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.3
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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.

• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.4
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• pp.383-389
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• 2011

At the design stage, it is very important to know the ship maneuvering characteristics from the view point of ship performance and for the safety of navigation. IMO only gives some criteria for ships in full load even keel condition. However, the ship generally is operated not only in full load condition but also in half load condition or ballast condition. Therefore we must estimate the ship maneuvering in different loading condition to ensure that the ship will satisfy with IMO rules and navigate safely in every condition. In this paper, we have investigated the maneuvering characteristics of a ship by simulation and experiments with real ship. By comparing with the results of simulation, the real ship tests conform with simulation test and previous researches. Therefore, the method base on real data is well done to estimate the ship maneuvering in different loading conditions. The change of ship's manoeuverability accoriding to ship's operation conditions was estimated.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.11a
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• pp.62-67
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• 2004

Many ships in voyage experience weight and buoyancy distribution change by various reasons such as change of sea water density and waves, weather condition, and consumption of fuel, provisions, etc . The weight and buoyancy distribution change can bring the ships out of allowable trim, heeling angle. In these case, the ships should adjust trim and heeling angle by shifting of liquid cargo or ballasting, deballasting of ballast tanks for recovery of initial state or for a stable voyage. But, if the adjustment is performed incorrectly, ship's safety such as longitudinal strength, intact stability, propeller immersion, wide visibility, minimum forward draft cannot be secured correctly. So it is required that the adjustment of trim and heeling angle should be planned not by human operators but by optimization computer algorithm. To make an optimized plan to adjust trim and heeling angle guaranteeing the ship's safety and quickness of process, Uk! combined mechanical analysis and optimization algorithm. The candidate algorithms for the study were heuristic algorithm, meta-heuristic algorithm and uninformed searching algorithm. These are widely used in various kinds of optimization problems. Among them, heuristic algorithm $A^\ast$ was chosen for its optimality. The $A^\ast$ algorithm is then applied for the study. Three core elements of $A^\ast$ Algorithm consists of node, operator, evaluation function were modified and redefined. And we analyzed the $A^\ast$ algorithm by considering cooperation with loading instrument installed in most ships. Finally, the algorithm has been applied to tanker ship's various conditions such as Normal Ballast Condition, Homo Design Condition, Alternate Loading Condition, Also the test results are compared and discussed to confirm the efficiency and the usefulness of the methodology developed the system.

• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.1
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• pp.1-6
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• 2016

Ballast water in ship operation is essential for a safe voyage. However ballast water can contain unwanted organisms that are the cause of disturbing the ecosystem by the transfer of potential invasive species. To prevent the destruction of the environment, the International Convention for the Control and Management of Ship's Ballast Water and Sediments(BWM Convention) was adopted in 2004. BWMS (Ballast Water Management System) has been developed to prevent the transportation of organisms to another region in order to fulfill the requirements IMO (International Maritime Organization) regulations. Nowadays there are about 50 approved Ballast Water Management Systems of various types globally. The most common BWMS types are UV (Ultra Violet), Electrolysis and Ozone. Among these types there are many difficulties in determining the optimum type of BWMS which can be suitable for the user and designer's requirements. The main objective of this research is to select the best BWMS type by using AHP. To apply AHP, the most important criteria for the BWMS development are derived by users and designers. From our results, we can give a guide BWMS type to the developers of BWMS.

• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.6
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• pp.530-539
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• 2013

In large vessels, proper water level must be maintained with a balance for right and left equilibrium by absorbing or draining sea water in ballast water tank. However, this ship's ballast-water can be drained marine organisms to local sea area by world trade and this can be a source of ecological disturb. In order to solve these problems, marine organisms must be removed in accordance with the international covenant for the emission of microorganisms. By this reason, the seawater electrolysis rectifier of low-voltage high-current rectifiers with excellent ability for microbial treatment is required. In this paper, PSFB converter will be discussed for the seawater electrolysis rectifier. Furthermore, a new output control method with the power limit operation under the limited maximum voltage condition is proposed for this rectifier. The simulation for the proposed current control method for PSFB Converter is shown using MATLAB/SIMULINK. Finally the usefulness of the proposed control method is presented by the experimental results.

• Corrosion Science and Technology
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• v.8 no.5
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• pp.177-183
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• 2009

There are two effective methods in use to protect ship ballast tank against corrosion. One is paint coating and the other cathodic protection(CP). The conventional cathodic protection design has mainly relied on the expert's experience. During the last two decades computer modeling has been significantly developed as an advanced design technology for cathoidic protection systems not only for ships, but also for offshore structures. However the present computer modeling of cathodic protection systems have some limitations simulating corrosion in the ballast tank with a deteriorated coating. In this study, "coating breakdown factor" considering coating degradation states with time has been attempted to improve the cathodic protection modeling using the data from literatures.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.356-359
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• 2003

선박이 배출하는 안정수(ballast water)는 외부로부터 유해 생물들이 유입되어 전파해 오는 주요경로로써, 해양환경 변화를 초래하는 매우 중요하고 위험한 일중의 하나이다. 그러나 이에 대한 효과적인 처리방법은 아직까지도 미흡한 상태이다. 선박 안정수에 포함되어 타 지역으로부터 옮겨지는 외래침입생물 처리 방안의 하나로, 강 전리방전 기술을 적용하여 고 밀집 산소와 물분자로부터 고농도 수산자유기(OH: hydroxyl radical)를 전리, 발생시켜서 활성입자를 신속히 확산시켜 비교적 낮은 수산기농도 하에서 유해성침입생물을 소멸 처리하는 환경 친화적 녹색 청정처리방법을 제안하였다. 제안된 기술은 대상물의 처리 후 부수적으로 발생할 수 있는 처리잔류물이 전혀 발생하지 않으며, 인공적 화학성분의 약제를 사용하지 않는 저렴한 처리방법이므로 대ㆍ소형 원양선박의 안정수에 들어있는 외래침입생물의 타 지역 해양확산을 안전하게 처리할 수 있는 자연치유적 신기술이다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.325-326
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• 2005

해양에 적조가 발생하면 해수의 산소결핍 현상을 유발하고 동식물의 성장과 생존에 필수적인 태양광을 차단하여 해양 동물뿐 아니라 식물에게까지 치명적 피해를 준다. 또한, 대형 선박의 안정수(ballast water) 유입시 안정수 내에 포함되어 그들의 생활공간을 이동하면서 선박으로부터 다시 유출될 때 신생활공간에 외래 생물체로 침입하여 그곳의 기존 생태계를 파괴시키거나 교란하는 외래침입생물체는 해양생태계 환경파괴의 주범이다. 따라서 이들 두 종류의 해양생물은 부분적으로 상관성을 지니는 해양수산업계의 천적이며, 해양생태환경 파괴의 원인 제공자로써 마땅히 과학적 방법으로 제거되거나 방지되어야 한다. 이 논문은 해양수산업 계에 막대한 피해를 끼치며 해양생태환경 파괴의 주범으로 등장한 적조생물과 외래침입생물체들이 해수로부터 제조한 플라즈마 반응생성물에 처리된 결과를 분석하여 그 응용성을 조사하였다.