• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.6
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• pp.839-847
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• 2011

Instrumentation & Control(I&C) System in NPP(Nuclear Power Plant) plays a important role as the brain of human being, it performs protecting, controling and monitoring safety operation of NPP. Recently, the I&C system is digitalized as digital technology such as PLC, DSP, FPGA. The different aspect of digital system which use digital communication to analog system is that it has potential vulnerability to cyber threat in nature. Possibility that digital I&C system is defected by cyber attack is increasing day by day. The result of cyber attack can be adverse effect to safety function in NPP. Therefore, I&C system required cyber security counter-measures that protect themselves from cyber threat efficiently and also cyber security design should be taken into consideration at concept stage in I&C system development process. In this study, we proposed the digital asset analysis method for cyber security assessment of I&C system design in NPP and we performed digital asset analysis of I&C system by using the proposed method.

• International Journal of Highway Engineering
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• v.14 no.2
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• pp.117-129
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• 2012

Road safety audit is the preventive enhancement strategy for safety. : it gets rid of beforehand the potential factor of a traffic accident in the stage of road planning and design and it evaluates the appropriation for road geometric structure or safety facility to prevent traffic accident in the stage of operation after the construction. Since this strategy is introduced to our country in the early 2000s, various projects have been processed and it was legislated recently. And now, the evaluation of past project for its continuation is needed. Therefore, in this study the evaluation of road safety audit on existing freeway is performed. The spatial extent of this study is Yong-dong line on which the safety treatment was executed in 2005 and 2006. And, the temporal range of this study is each 2-year of before and after from 2005 and 2006. The empirical bayes method of observational evaluation studies is applied to analyze. As a result, there is an effect of improvement on most of treated sections. But there is ineffective or negligible on some sections. Compared with the detail of treatment on each section, the effect of multiple or various treatments is good for that section. On the other hand, the section on which effect doesn't appear is the result of single or unimportant treatments. Throughout these results, the concrete analysis can be performed and the countermeasures designed for the section on which effect doesn't appear. Also it is used as reference to the future plan and direction of road safety audit on existing freeway.

• Journal of the Korean Institute of Rural Architecture
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• v.15 no.1
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• pp.13-20
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• 2013

Bird collisions with glass are a substantial source of human-caused avian mortality. It has been estimated that between 100 million and 1 billion birds die in collisions with windows every year, and bird-window collisions can have a particularly serious impact on populations because glass is dangerous for strong, healthy, breeding adults. The purpose of this study are to address the bird-window collision issue and to provide suggestions for bird-safe development by reviewing precedent studies on bird collision and analyzing bird-friendly design guidelines. Typically reflections of the sky, clouds or trees on glass, green plants in lobbies, and lights attract and confuse both migrating and resident birds. Therefore birds fatally fly into the glass because they do not recognize that reflections are false and that glass is a barrier. Many cities such as Toronto, Chicago and New York have made efforts on reducing the bird collision by encouraging the creation of environmentally conscious and bird-safe buildings. The USGBC also introduced a bird-safety credit as part of its environmental certification process, called LEED. The results of the study presented that architects and builders can help reduce or prevent bird from collisions in both new construction and existing structures with creative use of design elements. The measures to reduce bird collisions include using glass with an embedded pattern, opaque or translucent films, decals, dot patterns, awnings, louvers, and grilles. Turning off lights after midnight during the spring and fall migrations can be part of the solution as well. In order to reduce bird mortality, the most important thing is to generate awareness of the issue among designers, builders, as well as the public. Also local governments need to develop bird-friendly design guidelines and planning mechanisms to encourage bird-safe development and building operation.

• Journal of Navigation and Port Research
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• v.32 no.3
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• pp.223-228
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• 2008

As most of small fishing boats made of FRP have been constructed by experience in Korea, some structural safety problems have been occurred occasionally. To improve the structural strength and reduce the costs for construction and operation, optimum design for small fishing boat was carried out in this study. The weight of fishing boat and the main dimensions of structural members are chosen as objective function and design variables, respectively. By the combination of global and local search methods, a hybrid optimization algorithm was developed to escape the local minima and reduce CPU time in analysis procedure, and finite element analysis was performed to determine the constraint parameters at each iteration step in optimization loop. Optimization results were compared with the real existing fishing boat, and the effects of optimum design were examined from points of view; structural strength, material cost, etc.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.6
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• pp.652-660
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• 2017

Recently, the number of tourists using cruise ships in Korea is increasing. and an big cruise ship with an gross tonnage of 160,000 tons or more has entered the domestic ports. Therefore, the government has been making a lot of efforts to confirm the cruise infrastructure for revitalization of the domestic cruise industry. However, there are no standards for cruise ship specifications and water facilities in the domestic port and fishery design standards. Currently, construction of dedicated cruise facilities is under way in major domestic ports. However, due to lack of specifications and domestic standards for cruise ships, it is difficult to design and license special facilities. Therefore, in this study, PIANC rule and domestic harbor and designing standard of fishing port were compared and analyzed in order to present the standard specification of cruise ships. And analyzed the representative linearity of cruises currently being operated. As a result of the ship characteristics analysis, There was a difference in coastal passenger ship in specifications and ship maneuverability. Therefore, in order to design facilities dedicated to cruising, the specifications of the target ship must be included in the domestic design standard. In addition, in order to calculate the scope of the target ship, I applied the coverage rate of 75% to the average specification value of the cruise ship and presented the standards of the cruise ship and the standard of the water area facilities.

• Fashion & Textile Research Journal
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• v.21 no.5
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• pp.640-655
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• 2019

Technology status was investigated by analyzing patents and development cases of wearable robots. Development direction of wearable robot for wearability was also suggested by understanding the problems of wearability from development cases through the FGI technique. The number of patents per technical field was the most in the field of strength support, but AI in the technology field was different in each country; Korea was found to be poor in the category of daily living assistance. The number of patents by technology category was the most in the category of muscular strength assistance. However, the values of AI in the technology category were different in each country; Korea was found to be poor in the category of daily living assistance. Development cases were focused on rehabilitation, so development is not fulfilled uniformly by use purpose. By wearing body parts, robots with single function type were mainly developed. Rigid material robots were mainly developed. It was confirmed that wearable robot technology is not developed evenly in the category of application because it is in the early stage of the technical proposal and centered on main performance improvement. We derived twelve wearable conditions for wearable robots: Shape and Size Appropriateness, Movement Appropriateness, Composition Appropriateness, Physiological Appropriateness, Performance Satisfaction, Ease of Operation, Safety, Durability, Ease of Dressing, Ease of Cleaning, Portability and Ease of Storage and Appearance Satisfaction. Finally, the development direction of a wearable robot for each wearable condition was suggested.

• Journal of Ocean Engineering and Technology
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• v.35 no.6
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• pp.446-456
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• 2021

To build an environment facility of a large-scale ocean basin, various detailed reviews are required, but it is difficult to find data that introduces the related research or construction processes on the environment facility. The current generator facility for offshore structure safety evaluation tests should be implemented by rotating the water of the basin. However, when the water in the large basin rotates, relatively large flow irregularities may occur and the uniformity may not be adequate. In this paper, design and review were conducted to satisfy the performance goals of the DOEB through computational numerical analysis on the shape of the waterway and the flow straightening devices to form the current in the large tank. Based on this, the head loss, which decreases the flow rate when the large tank water rotates through the water channel, was estimated and used as the pump capacity (impeller) design data. The impeller of the DOEB current generator was designed through computational numerical analysis (CFD) based on the lift surface theory from the axial-type impeller shape for satisfying the head loss of the waterway and maximum current velocity. In order to confirm the performance of the designed impeller system, the flow rate and flow velocity performance were checked through factory test operation. And, after installing DOEB, the current flow rate and velocity performance were reviewed compare with the original design target values. Finally, by measuring the current velocity of the test area in DOEB formed through the current generator, the spatial current distribution characteristics in the test area were analyzed. Through the analysis of the current distribution characteristics of the DOEB test area, it was confirmed that the realization of the maximum current velocity and the average flow velocity distribution, the main performance goals in the waterway design process, were satisfied.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05b
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• pp.657-662
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• 1996

Venting capability to prevent excess pressurization caused by loss of Residual Heat Removal System (RHRS) during mid-loop operation hat been evaluated analytically and the peak Reactor Coolant System (RCS) pressure was compared with the results of the MIDLOOP computer code. Even though analytical method if relatively simple, the results are in a good agreement with those of the computer code. For both methods, the peak pressures have not, exceeded the nozzle dam design pressure, if the vent paths such as pressurizer safety valves or a pressurizer manway are available in a closed RCS configuration with the nozzle dam installed.

• Journal of Korea Ship Safrty Technology Authority
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• s.37
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• pp.35-44
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• 2014

해상 및 육상용 살균방식으로 UV를 사용하는 시스템이 주종을 이루고 있으며, 의료, 생활, 산업용 시스템에 널리 적용되고 있으며, 근래에는 평형수 처리 방식으로 UV를 적용하는 사례가 등장하고 있다. UV 광원으로는 다양한 램프가 있으며 그 중 제논플레시 램프는 강한 섬광형 방전과 함께 다량의 UV를 방출하는 특성이 있어 매우 효과적이다. 다만, 타 광원에 비하여 높은 방전전압으로 인하여 기존의 전원장치 설계 방식으로는 장치의 크기가 크고 복잡한 문제가 있었으며, 이를 개량하기 위한 본 연구에서는 트랜스포머의 자가 공진(self-resonance)을 이용한 설계 기법을 제안하며, 트랜스포머의 특정주파수에서 고유임피던스 성분을 이용하여 출력전압을 필터링하면 제논방전관이 자가 발진방식으로 동작하므로 종래의 회로구성보다 간단하고 경제적인 아크방전 파워 스테이지의 구성이 가능하다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.1051-1053
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• 2017

We have designed the vent relief valve to set bi-level safety pressure for oxidizer tank. The minimum cavity volume was calculated to reduce the pressure deviation, and the valve operation characteristics was analyzed by using modeling. We have a plan to manufacture the validation model based on the analysis results.