• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.1
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• pp.40-50
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• 2013

This study is aimed to find a control factor for the marine casualty of fishing vessel by using the risk quantitative method of marine casualty, and sequentially timed event analysis for the reason finding. The result is that collision, sinking, and capsizing took high risk need to be strongly controlled. And the accident reason and control factors distinguished are as follows. The 82.2% of collided fishing vessels have negligence of look out as a immediate cause, while it was judged that underlying causes were the characteristics of vessels and fishing method, lack of suitable complement, fatigue, the prejudice or ignorance on steering and sailing rules. So the control factors are; firstly needs educational control measures and in terms of systemic control approach expand the range of the certificate of competency more smaller tonnage.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.1
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• pp.179-202
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• 2014

This study was carried out to reduce the number of marine accidents on versatile small ships and to minimize the casualties. The study looked into the compulsory education systems regarding embarkation on small ships such as the Korean Marine Officers Act, conducted a survey targeting on the education receivers to suggest problems, and drew a conclusion. Conclusions are as follows. First, it is needed to give education opportunities in the system by increasing the recipients of the Ships Officers Act, and to simplify the compulsory education by separating similar courses from the education regulated by the Korean Marine Officers Act, and by establishing integrated courses suitable to each size and facility of ships. Second, in cases where the compulsory education courses of different purpose of ships by other legislations are similar, it is necessary to expand the scope of the inter-education so that corresponding year's education is exempted. Third, by classifying the education ares, the education courses should be based on case studies and the audiovisual or field education that correlates relevant expertise should be managed within a reasonable time frame. Fourth, it is needed to enhance the education effect by converting the regular education courses to practical courses by different ships for safe navigation, and is also needed to review the system so that special courses for safe navigation can be carried out in each region on a regular basis by expanding both human and financial support of special institutions.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.3
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• pp.304-310
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• 2014

Based on atmosphere weather data by balloon in Osan and Gwangju area, if icing condition occurs in weather environment of altitude range where helicopter is operated was analyzed in quantitative way. Yearly icing occurrence frequency for daytime during recent three years was average 102 days in Osan, average 91 days in Gwangju. Icing weather environment to highly affect operation of helicopter varies a little according to analysis methods but icing intensity at MDT level was calculated in all the methods, and 14.5~38 times was suggested in Osan; 2.5~30 times in Gwangju. Icing at MDT level was calculated in common in all the analysis methods through wide periods such as Jan., Feb., Mar., and Nov. in Osan. In Gwangju, icing at MDT level was suggested focusing on Jan. only. Therefore, military helicopter developed in Korea is required to strive obtaining certificate of airworthiness about icing condition at MDT level for implementation of perfect operational mission and safe operation.

• Journal of the Korea Convergence Society
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• v.9 no.7
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• pp.69-75
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• 2018

The key technology of Industry 4.0, Smart factory is evaluated as the driving force of our economic development hereafter and a lot of researches have been established. Various entities including devices, products and managers exist in smart factory, but roles of these entities may be continuous or variable and can become extinct not long after. Existing methods for access control are not suitable to adapt to the variable environment. If we don't consider certain security level, important industrial data can be the targets of attacks. We need a new access control method satisfying desired level of efficiency and security without excessive system loads. In this paper, we propose a new RBAC-PAC which extend AC defined for PKC to the authority attribute of roles. We distribute PACs for roles through block chain method to provide the efficient access control. We verified that RBAC-PAC is more efficient in the smart factory with large number of entities which need a frequent permission update.

• Journal of Industrial Technology
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• v.21 no.B
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• pp.75-83
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• 2001

In the field of secure information systems including electronic commerces, public key infrastructure(PKI) is widely used for secure services. The more PKI domains are established, the more needs are required for cross-domain certifications. Furthermore, each country has many certificate authorities(CA) which require more complex cross certification: We may need a fast algorithm in order to find the possible certification paths. This will be more indispensible in the growing PKI systems. We designed and implemented the high-speed certification path discovery algorithm. Also, we investigated the feature of operation of the system.

• Proceedings of the Korea Contents Association Conference
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• 2004.11a
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• pp.220-227
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• 2004

In this paper, we made out blocking probability analysis for a new authentication structure for reducing the certificate acquisition time which is one of the factors that should be improved in a conventional wireless PKI. A conventional key exchange method simply performs the key exchange setup step based on discrete algebraic subjects. But the mutual-authentication procedure of wireless PKI for reducing authentication time uses an elliptical curve for a key exchange setup step. Besides, we proposed advanced handover method and blocking probability analysis for wireless PKI.

• Journal of Acupuncture Research
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• v.36 no.1
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• pp.28-32
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• 2019

Background: The purpose of this study was to collate inventors' improvements of air extraction cupping technology by reviewing patent applications in Korea. The cost of procurement and use of air extraction cupping devices are covered by health insurance. Methods: Patents registered in Korea for air extraction cupping devices from August 1992 to January 2018 (registration, expiration, rejection, abandonment, and disclosure) were analyzed to determine technology trends. The Korean patent search engine used was Kipris (www.kipris.or.kr). Results: Sixty-seven Korean patents for air extraction cupping devices were retrieved. Most patents focused on design of the top valve of the device, the device at the bottom, an internal device, and the disposable cupping glass. In total 17.9% of patents were registered and 64.2% were abolished [either from non-payment of registration fees (93%) or expiration of the patent after 10 years (7%)]. The average registration period was 3.7 years. Conclusion: The patents retrieved for this study focused on the development of the air exhaust valve, disposable cups, and skin adhesion maintenance technology in cupping devices that use air extraction. The average registration period was 3.7 years, meaning the patents that were not commercialized, expired without additional registration renewals. It is important to acquire a New Excellent Technology certificate for a cupping device to promote commercialization.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.54 no.2
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• pp.173-180
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• 2018

Marine casualties of small fishing vessels (SFV) of less than 20 tons are frequent in Korea. The analysis was conducted to identify the cause and then prepared reduction plan using the marine casualty statistics of fishing vessels for the last five years from 2012 to 2016 by the Korean Maritime Safety Tribunal to reduce the marine casualties of SFV. According to the analysis of the type of whole vessels occurring marine casualty, fishing vessels accounted for an average 68.0 %; moreover, except for 2014 when M/V SEWOL ferry capsizing occurred, the rate of death and missing due to marine casualties occurred from 68.3 % to 91.2 % in fishing vessels, and an average 79.5 % was found to be urgent need of a measure. Marine casualties occurrence depending on the gross tonnage of fishing vessel was found that the most occurred at less than 5 tons, followed by the order of 5 to 10 tons or less. However, crews who boarded on SFV do not have any training program for them, except for the fishing safety training of fisher who carry out fishing for shipowners and crew of the coastal and offshore fishing vessel in accordance with the safety regulations for fishing vessels in the Fisheries Cooperative Association. Therefore, it is necessary to revise the training program so as to improve the preventive action and then emergency response including the fishing safety compliance with each fishery, safe navigation, machinery inspection and emergency response. Also, an SFV of less than 5 tons of 56,000 vessels is boarded by unqualified fishers. It would also be possible to consider subdividing small boat operator's certificate to enhance their qualifications. It is expected that marine casualties of SFV will be reduced if active efforts are made to improve the safety consciousness of fisher and shipowners as well as the reorganization of fishing safety training and the small boat operator's certificate system.

• Journal of Energy Engineering
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• v.26 no.2
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• pp.99-120
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• 2017

In SS branch of Korea District Heating Corporation, Combined Heat & Power power plant with 99MW capacity and 98Gcal / h capacity is operated as a district electricity business. In this region, it is difficult to operate the generator due to the problem of surplus heat treatment between June and September due to the economic recession and the decrease in demand, so it is urgent to develop an economical energy new business model. In this study, we will develop an optimized operation model by introducing a renewable energy hybrid system based on actual operation data of this site. In particular, among renewable energy sources, fuel cell (Fuel Cell) power generation which can generate heat and electricity at the same time with limited location constraints, photovoltaic power generation which is representative renewable energy, ESS (Energy Storage System). HOMER (Hybrid Optimization of Multiple Energy Resources) program was used to select the optimal model. As a result of the economic analysis, 99MW CHP combined cycle power generation is the most economical in terms of net present cost (NPC), but 99MW CHP in terms of carbon emission trading and renewable energy certificate And 5MW fuel cells, and 521kW of solar power to supply electricity and heat than the supply of electricity and heat by 99MW CHP cogeneration power, it was shown that it is economically up to 247.5 billion won. we confirmed the results of the improvement of the zone electricity business condition by introducing the fuel cell and the renewable energy hybrid system as the optimization process model.

• Journal of Aerospace System Engineering
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• v.14 no.1
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• pp.44-53
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• 2020

In conjunction with the Fourth Industrial Revolution, the unmanned aerial vehicle industry is being developed to a new paradigm by combining advanced technologies such as AI, Big Data and the IoT. Aeronautical developed countries such as the U.S. are focusing their efforts on the development of the safer unmanned aerial vehicles. The Korea Aerospace Research Institute, as part of the national R&D project in 2011, had succeeded in developing the first vertical takeoff and landing (VTOL) UAS, called Smart-UAV. However, although the development technology of the VTOL UAS is possessed, developing and operating of the VTOL UAS for commercial or military use are limited. The type certification procedure of the VTOL UAS developed by domestic technology is stipulated in the Korean Aviation Safety Act, but the Korean VTOL UAS airworthiness standards (KAS) hsve not been established. Thus, this study investigated the development trends of the VTOL UAS in Korea and abroad and national certification systems and procedures, and benchmarked the special conditions for the VTOL aircraft, announced by the EASA on July 2, 2019, to establish standards for type certificate of the VTOL UAS in Korea.