• Journal of Navigation and Port Research
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• v.43 no.1
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• pp.33-41
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• 2019

In December 2012, a pile driving boat sunk off the coast of Ulsan port in Korea. The cause of capsizing of these boats was considered a complex problem. Although Korean Ship Safety Technology Authority concluded that leaders (cranes) of the vessel were designed with sufficient safety factors, National Forensic Service concluded that the capsizing was caused by the failure of leaders. This study reviewed the related laws, strength calculations, and structural analysis methods used by the Korea Ship Safety Technology Authority. In addition, numerical simulations were carried out on hydrodynamic analysis and structural analysis to analyze the cause of vessel capsizing based on the rules of the Korean Register of Shipping. The results were similar to those found by National Forensic Service. In conclusion, the study suggested that inspection especially for a pile driving boat subjected to the Korean Register of Shipping rules should be carried out to prevent the similar accident.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.2
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• pp.211-218
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• 2021

This paper addressed the problems of controlling the coupled pitch-roll motions in a marine vessel exposed to the regular waves in the longitudinal and transversal directions. Stabilization of the pitch and roll motions can be regarded as the essential task to ensure the safety of a ship's navigation. One of the important features in the pitch-roll motions is the resonance phenomena, which result in unexpected large responses in terms of pitch and roll modes in some specific conditions. Besides, owing to its inherent characteristics of coupled combination and nonlinearity of restoring terms, the vessel shows various dynamical behaviors according to the system parameters, especially in the pitch responses. Above all, it can be seen that suppression of pitch rate remains the most significant challenge to overcome for ship maneuvering safety studies. To secure the stable upright condition, a quasi-sliding mode control scheme is employed to reduce the undesirable pitch and roll responses as well as chattering elimination. The Lyapunov theory is adopted to guarantee the closed stability of the pitch-roll system. Numerical simulations demonstrate the effectiveness of the control scheme. Finally, the control goals of state convergences and chattering reduction are effectively realized through the proposed control synthesis.

• The Korean Journal of Air & Space Law and Policy
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• v.32 no.1
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• pp.3-51
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• 2017

From a historical point of view, while the Warsaw Convention was passed in 1924 to regulate the unified judicial responsibility in the global air transportation industry, protection of airline consumers was somewhat lacking in protecting air carriers. In principle, the air carrier does not bear any obligation or liability when the aircraft is not operated normally due to natural disasters such as typhoon or heavy snowfall. However, in recent years, in developed countries such as the US and Europe, there has been a movement in which regulates the air carriers' obligation to protect their passengers even if there is no misconduct or negligence. Furthermore, the legislation of such advanced countries imposes an obligation on the airlines to compensate the loss separately from damages in case the abnormal operation of the aircraft is not caused by force majeure but caused by their negligence. Under this historical and international context, Korea is also modifying the system of aviation consumer protection by referring to other foreign legislation. However, when compared with foreign countries, our norm has a few drawbacks. First, the airline's protection or care obligations are mixed with the legal liability for damages in the provision, which seems to be due to the lack of understanding of the airline's passenger protection obligation. The liability for damages, which is governed by the International Convention or the Commercial Act, shall be determined by judging the cause of the airline's liability in respect of the damage of the individual passenger in the course of the air transportation. However, the duty to care and the burden for compensation shall be granted to all passengers who feel uncomfortable with the abnormal operation regardless of the cause of the accident. Also, our compensation system for denied boarding due to oversale is too low compared to the case of foreign countries, and setting the compensation amount range differently based on the time for the re-routing is somewhat unclear. Regarding checked-baggage claim, it will be necessary to refund the fee only from the fact that the baggage is delayed without asking whether there is any damage occurred from the delayed baggage. This is the content of the duty to care, which is different from the current Commercial Act or the international convention, in which responsibility is different depending on whether the airline takes all the necessary measures in order to prevent delaying of the baggage. The content of force majeure, which is a requirement for exemption from the obligation to care passengers on the airplane, shall be reconsidered. Maintenance for safe navigation is not considered to be included in force majeure, and connection to airplanes, airport conditions are disputable. According to the EC Regulation, if the cause of the abnormal operation of the airline is force majeure, the airline's compensation obligation is exempted but the duty to care of airline company is still meaningful. Furthermore, even if the main role of aviation consumer protection is on an airline, it is the responsibility of government agencies to supervise the fulfillment of such protection obligations. Therefore, it is necessary for the Korean government to actively take measures such as enforcing incentives for airlines that faithfully fulfill their obligation to care and imposed penalties on the contrary.

• The Korean Journal of Air & Space Law and Policy
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• v.17
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• pp.111-132
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• 2003

The air transport industry is the most important as means of human exchange between the countries. Because the spread effect and the durability by aviation cooperation between the countries are much higher than any other industry, a research about air transport industry is very important to allied industry field as well as national policy about International cooperation and integration. Specially, according to the economic interchange with North Korea becomes active, the role of air transport as related traffic network with North Korea becomes more important. The number of flights is increasing sharply after South-North summit meeting, and two sides established and are using temporary direct route between South-North Korea. When we consider that the number of flights utilizing temporary direct route is increasing every year, It is not desirable to use temporary routes continuously because the current agreement between South and North cant be reliable far the case of unexpected circumstance. In addition, the current agreement is not based on the international standards. The paper is to study the condition to promote the coordination of civil aviation in the whole Korean peninsula. As known, the aviation system in North Korea is mainly operated by military unit. The study will review the current status of air transport system of South and North and the effective way of cooperation of civil aviation between both sides. The cooperation between governments as well as between airlines is studied. The establishment of Air Traffic Service Agreement is going to be handled heavily because the stable air traffic service is the most required base for the operation of air transport. The authors also try to find a way to support the development of infrastructure of aviation industry in North Korea.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.3
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• pp.411-418
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• 2017

In the domestic case, although technological capabilities are recognized globally in the IT field, it is actually that the technical capabilities of the domestic leisure ship market which is formed mainly by fishing vessels are not beyond their technical capabilities At the point where the GNP of our country already goes over 22,000 dollars, the demand for the products related to the middle and small leisure boats is gradually increasing, but most of the high added value products depend on the imports from U.S.A. and Europe. And in case of the cars, with the Car Navigation as the start, products which satisfies various demands of the users are coming out in large quantity and now the IT technology is the necessity which can not be lived without in the car industry. Thus, if the digital ship navigator which jointed the recent ICT technology which was applied to the land for the domestic middle and small leisure ships by utilizing the embedded hardware technology and mapping technology which are credible is developed and distributed, it will become not only the opportunity to improve the industry related to middle and small ship IT, but also, the export about overseas market can be expected.

• Journal of Internet Computing and Services
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• v.21 no.4
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• pp.117-126
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• 2020

A maritime object detection system is an intelligent assistance system to maritime autonomous surface ship(MASS). It detects automatically floating debris, which has a clash risk with objects in the surrounding water and used to be checked by a captain with a naked eye, at a similar level of accuracy to the human check method. It is used to detect objects around a ship. In the past, they were detected with information gathered from radars or sonar devices. With the development of artificial intelligence technology, intelligent CCTV installed in a ship are used to detect various types of floating debris on the course of sailing. If the speed of processing video data slows down due to the various requirements and complexity of MASS, however, there is no guarantee for safety as well as smooth service support. Trying to solve this issue, this study conducted research on the minimization of computation volumes for video data and the increased speed of data processing to detect maritime objects. Unlike previous studies that used the Hough transform algorithm to find the horizon and secure the areas of interest for the concerned objects, the present study proposed a new method of optimizing a binarization algorithm and finding areas whose locations were similar to actual objects in order to improve the speed. A maritime object detection system was materialized based on deep learning CNN to demonstrate the usefulness of the proposed method and assess the performance of the algorithm. The proposed algorithm performed at a speed that was 4 times faster than the old method while keeping the detection accuracy of the old method.

• The Korean Journal of Air & Space Law and Policy
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• v.12
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• pp.144-177
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• 2000

Our nation have several procedures and law for national airspace management, however those procedures and law not enough to manage airspace. Therefore, I have studied this paper for improving flight safety and for providing economics flight of civcil aircraft and military aircraft, also, for increasing efficiency of airspace through systematic airspace management, additionally, for improving nation defense ability and for preventation our nation damage when occuring airspace problem. Nowaday. in using airspace. two theory which freely use theory and use theory under jurisdiction is opposed by every nation in worldwide. Consequently. we can realize every nation endeavour to increase their jurisdiction airspace. However. our nation is not still prepared to cope with other nation when occuring airspace trouble. because airspace definition is not prescribed on our aviation law. Therefore. several problems which are improved in our airspace management are presented on this paper. The presented matters are as follows. First, The airspace definition is not prescribed on aviation law and responsibility limit of airspace management is ambugious. Second. problem on structure of approach control area and special airspace, Third. problem on airway system. Fourth. civil agency and military agency apply respectively different regulation in establishment of aircraft flight route, To grasp these problems, considered the airspace conception, airspace classfication. legal character of airspace. our nation airspace state and management together with other nation airspace state and management. also compared our nation airspace management with other nation airspace management. And. improvement methods to solve problems which was appeared by comparing and analysis are presented on this paper.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.6
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• pp.611-616
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• 2013

Many researches have been carried out consistently for the green ship owing to its economic increasement, efficiency and convenience. One of them is an electronic controlled marine diesel engine. However, we are suffered from dissemination of above engine, due to its anxiety about safety and reliability. In order to solve these problems in this study, emission characteristics test of main propulsive two-stroke diesel engine, equipped both electronic control and cam drive fuel injection systems, has been performed and evaluated under the various load conditions. From the test results, we have confirmed that exhaust gas emission characteristics of the electronic control system is similar to the cam drive system in eco-mode operation, but NOx in emission mode has been decreased 100ppm or more in full load condition. HC emission from the electronic control system is decreased 10~20ppm at 50% load, and 35~40ppm at 25% load in comparison to cam drive system. In fuel consumption, it is considered that 7g/kWh is decreased than the value of cam drive system at 700bar of injection pressure, which is 200bar higher than cam drive system.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.6
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• pp.527-534
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• 2017

The purpose of this study is to develop unmanned equipment that can automatically move to the desired point and measure water quality at the correct depth. For this purpose, we constructed a water sampling lift and water sampling container, an unmanned vessel equipped with a VRS-GPS, an acoustic echo sounder, and a water quality sensor. Also, we developed an automatic navigation algorithm and program, an automatic water sampling program, and a water quality map generation program. As a result of the experiment in the detention pond, the unmanned vessel sailed along the planned route with an accuracy of about 93% within the error range of 3m. In addition, the water quality sensor installed in the lift was able to acquire the water quality of the target area in real time and transmit it to the server via wireless Internet, and it was possible to monitor the water quality of each site in real time. Through field experiments, the water sampling lift was able to control the desired length with an accuracy of about 94%. The stretch length accuracy experiment of the water sampling lift was impossible to measure directly in the water, so it was replaced land-based experiment. We also found some unstable problems due to the weight of the water sampling lift and the weight of the air compressor to operate the water container. Except these two problems, we accomplished purpose of this study. An automated water quality measurement method using an unmanned vessel can be used to measure the quality of water in a difficult to access area and to secure the safety of the worker.

• The Journal of Aerospace Industry
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• s.68
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• pp.80-94
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• 2006

유효경쟁시장은 사업자의 수와 시장구조 측면에서는 독과점적인 시장이더라도 기존사업자간 경쟁이 상당히 치열하거나 잠재적 진입에 의한 경쟁압력이 커서 특정사업자가 시장지배력을 보유하거나 이를 행사하기 어려운 시장상태를 말하며, 항공산업의 경우 일반적인 네트워크 산업과 마찬가지로 대규모 설비투자가 필요하고 높은 고정비용과 규모의 경제가 뚜렷한 특성을 갖고 있으며 네트워크효과도 강하게 나타나 비대칭적 규제가 필요한 대표적인 산업이라고 할 수 있다. 우리나라 경제당국은 평균비용이 장기적으로 하락하는 대규모 자본산업에서 자연독점이 발생할 경우, 그 피해는 자연히 소비자에게 돌아 갈 것이며, 미국과 EC의 경쟁법상의 유효경쟁의 개념으로 제시되고 있는 요소들을 보면 주로 어느 한 기업이 시장지배력을 행사하는 시장상황을 나열하여 규제함으로써 최대의 이익이 소비자에게 돌아가도록 규제하고 있다. 항공운송사업은 자본집약적 서비스산업으로 일반서비스 산업에 비해 상대적으로 일정수준까지 자본투자가 전제되어야 하는 자본집약적 특성을 지닌다. 따라서 항공운송산업의 성패는 대규모 자본을 통한 운송능력에 대한 효율화 정도에 따라 결정된다. 여기에 시장에 진입 시기와 독점 유지기간도 중요한 역할을 한다. 또한 항공운송산업은 정부의 면허사업으로 선발항공사가 수익노선을 선점하여 운항할 경우, 정부의 별도 허가에 의하여 복수취항이 이루어진다고 하더라도 운항편수 및 고객 선호 시간대를 미리 선점할 수가 있어 후발항공사에 비해 우월적 지위를 갖게 되어 공정경쟁이 극히 어렵다고 할 수 있는데, 이는 수십년간 아시아나의 압도적인 서비스/안전에 대한 높은 평가에도 불구 대한항공과 아시아나의 격차는 2000년 이후 일정하게 유지되고 있다는 점에서 확인할 수 있다. 국내 항공운송산업은 면허산업으로, 운수권의 확보에 따라 항공사의 매출 차이가 결정되는 바, 항공운송산업에서의 유효경쟁을 확보는 1차적으로는 정부의 운수권 배분을 통하여 실현되며 양사의 운수권 배분내역에 의하면 선발사업자에 대한 유효경쟁정책이 실현되지 않고 있다고 할 수 있다. 대부분의 노선에서 복수취항이 허용된다고 하더라도 강력한 스케줄, 가격(운임) 경쟁력, 선발항공사의 이점, 고객 선호도의 미반영 등으로 인하여 공정한 경쟁이 이루어지지 않을 가능성이 매우 높다. 이처럼 평균비용이 장기적으로 하락하는 항공산업에서 선발항공사에 대한 쏠림 현상이 가중된다면 향후 10년내에 국내 항공운송산업에 자연 독점이 발생할 가능성은 매우 크며 그 피해는 소비자에게 돌아갈 것이 자명하다. 결국 우리나라의 항공운수산업에서의 유효경쟁환경을 조성하기 위해서는 운수권 배분 절차에서의 비대칭규제의 원리가 상당기간 적용되어야 하며, 복수취항이 허용된 노선에서도 후발사업자가 공정하게 경쟁할 수 있도록 비대칭규제방안이 강구되어야 한다. 뿐만아니라 보충적으로 공정거래법상의 시장지배적 지위의 남용규제와 같은 비대칭규제도 강력하게 집행되어야 할 것으로 판단된다.