• 항공우주산업기술동향
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• 제9권1호
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• pp.158-164
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• 2011

항공우주용으로 개발되거나 활용 가능한 상업용 체크밸브사례가 조사되었다. 개발사례로 발사체용, 높은 수명이 요구되는 NASA의 SSME (Space Shuttle Main Engine) 및 지상 지원 시스템 퍼지 라인용과 국내에서 개발된 체크밸브가 있다. 상용품은 미국 주요 밸브개발업체의 제품을 상온용과 극저온용으로 분류하여 조사하였다. 또한 운용 온도, 운용 압력 및 크래킹 압력과 같은 주요 성능과 관련된 씰의 재질, 스프링 강성과 같은 설계 인자의 관계도 설명되었다. 이러한 단품 성능 이외에 채터 및 오염과 같은 운용상의 문제점과 일반적인 해결방안도 언급되었다. 또한 기타주의사항으로 필터, 피팅과 청정도 요구조건에 대하여도 조사되었다

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2004년도 춘계학술대회 발표 논문집
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• pp.179-184
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• 2004

This paper is an overview of the experimental work using a Planar Magnetic Levitation Stage System structure proposed by Dr. Won-Jong Kim in his PhD thesis. Based on his results, we built an Experimental Test Stand (ETS), which enabled us to get accustomed with the new technology and to create new control structures and algorithms. The ETS is controlled by a powerful controller made of 4 DSPs mastered by a PC. This controller structure increases the controller bandwidth up to 10 kHz leading to a better emulation of an analog controller and leaving enough room for further development. Based on analyzing all the factors that can affect the performances of the system, we achieved a great accurate positioning performance of sub-nanometer RMS value.

• 한국환경복원기술학회지
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• 제1권1호
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• pp.95-101
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• 1998

In order to seek a efficiency of site cooperation and slope stabilization in a rock sloping work, it would rather take into consideration, in its importance, a concurrent performance of civil works and landscaping works than give any part a special priority. It can enable us to achieve an expanded scope of landscaping works and improvement of slope scenery via this sort of cooperation. However, this can not be achieved without assurance on the slope stabilization and scenic view of the project owner, and further via this cooperation, environmentally familiar works can be performed, becoming natural environment and minimizing damages on surrounding scenery and environment. It is foreseeable that improvement of functions of civil equipment, introduction of technology and development of landscaping materials can facilitate an improvement in the betterment of slope scenery. Landscaping related parties need to enhance their understanding of rock sloping and scenic view based on knowledge on the fundermental understanding of slope stabilization and on the base rock characteristics.

• 한국군사과학기술학회지
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• 제17권2호
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• pp.275-281
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• 2014

Although self-propelled artilleries are mobile equipment, they need their own covered-positions for survival against preemptive strikes. The most important military requirement is enough protective capacity against blast pressure caused by explosion. This paper aims to assess the protective capacity of the newly-placed concrete box-type artillery positions using accurate structural geometric models as well as soil-structure interaction analysis. The commercial program is used to model the structural geometry of the positions. In order to describe the correct wave propagation in the backfill along with soil-structure interaction, used parameters in shock equation of state are selected based on the related studies as well as theories and then their final results are verified with the ones calculated with empirical equations in the US Unified Facility Criteria. In sum, it could be concluded that the protective capacity of the newly-built positions satisfies the protective structural requirement.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.497-497
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• 2007

We developed the light medical therapy apparatus for external injury cure using a ${\mu}$-controller. This equipment was fabricated by using a high brightness LEDs and a ATmega 128, and designed to enable us to control irradiation timer, intensity and reservation. Especially, to control the light irradiation frequency, and to control the change of output value, TLC5941 was used. Control stage is divided into 4 step by program. Consequently, the current value could be controlled by the change of level in Continue Wave(CW) and the output of a high brightness LEDs could be controlled, stage by stage. In this paper, the designed device was used to find out how a high brightness LEDs light source affects the skin wound of a small animal. In result, compared with none light irradiation animal, the lower incidence of inflammation and faster recovery was shown in light irradiation animal.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2003년도 추계학술대회 및 정기총회
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• pp.3-10
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• 2003

Developments in science and technology based on computer technology influenced military fields and created up-to-date weapons and equipment, and as a result, which is changing the war accomplishing methods of the future warfare. Due to these changes in the war accomplishing methods, the army command centers are requested to make changes in their decision-making process. In other words, they need to apply more scientific methods rather than just build a scheme by the mere analysis of commanders and the staffs as in the past. Consequently, we propose a model, Vision 21 we developed as a war game model for division-size unit analysis use, in the COA development process, which is the most important part in establishing the OPLAN for mission accomplishment. Vision 21, with a comparative analysis of the other COA built in the COA development process, can be applied to making the best COA. Model employment concept can let us choose the best COA, operating war games on condition that the COA of the opposite forces is fixed and ours sequentially opposed against, and with a comparative analysis also. Moreover, if the time available is limited, before establishing several courses, we can apply the COA to the process for making the best decision, analysing in stages or by main phases and not establishing several courses for a special purpose.

• 대한안전경영과학회지
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• 제17권3호
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• pp.33-44
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• 2015

Domestic plant construction sites have a tendency to become bigger, more various and complicated. Moreover frequency of industrial incident is increasing due to short project period, coexistence work condition and using heavy construction equipment. Installing safety facilities and safety training contribute to prevent incident. But mostly incident happens due to workers' unsafe action and wrong work method. Technically, it is very difficult for us to closely manage workers preventing incident. Therefore, the role of foreman who ordinarily works together with his workers is considered more important. Specific execution plan was drawn through industrial incident statistics from Ministry of Labor and questionnaire survey to interest parties(supervisor, safety staff and foreman). If foreman has raised sense of belonging and responsibility by conducting practical safety training for his workers, manages job site and receives proper compensation for these roles, it will be expected that it fully influences incident decrease.

• 한국기계가공학회지
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• 제20권12호
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• pp.85-91
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• 2021

In our daily life, artificial intelligence performs simple and complicated tasks like us, including operating mobile phones and working at homes and workplaces. Artificial intelligence is used in industrial technology for diagnosing various types of equipment using the machine learning technology. This study presents a fault mode effect analysis (FMEA) of start motors using machine learning and big data. Through multiple data collection, we observed that the primary failure of the start motor was caused by the melting of the magnetic switch inside the start motor causing it to fail. Long-short-term memory (LSTM) was used to diagnose the condition of the magnetic locations, and synthetic data were generated using the synthetic minority oversampling technique (SMOTE). This technique has the advantage of increasing the data accuracy. LSTM can also predict a start motor failure.

• Steel and Composite Structures
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• 제29권5호
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• pp.669-680
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• 2018

The rapidly decreasing natural resources and the global variation of the climate push us to find intelligent and efficient structural systems to provide more people with fewer resources. This paper proposed a kinematic cable-strut system to realize sustainable structures in responding to changing environmental conditions. At first, the concept of the kinematic system based on crystal-cell pyramid (CP) cable-strut unit was given. Then the deployment of the structure was studied experimentally. After that, the static behaviors in the fully deployed state under the symmetric and asymmetric load cases were investigated. Moreover, the effects of thermal loading and the initial prestress distribution were also discussed. Comparative studies between the proposed structure and other deployable cable-strut system under three times of design load cases were carried out. Finally, the robustness of the system was studied by removal of one passive cable at one time.

• 한국산업보건학회지
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• 제28권4호
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• pp.416-424
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• 2018

Objective: The objective of this study was to estimate the numbers of employees occupationally exposed to noise according to their industry and size. Methods: A Delphi panel consisting of 15 occupational health experts estimated the exposure prevalence of noise in workplace. Data on Industrial Accident Compensation Insurance provided from Occupational Safety and Health Research Institute were combined to produce the exposure population. Results: In Korea, 16.0% of employees, 2,539,890 out of 15,838,926, was estimated to exposed to noise occupationally. The rate was 32.7% and 10.3% in manufacturing sector and non-manufacturing sector, respectively. The highest rate, 52.5%, was found in manufacturing industries of wood and of products of wood and cork(except furniture) and of other transport equipment. Sorted by their size of business, the rate was higher as the number of employee was larger in manufacturing sector. Conclusions: Compared to the same rate estimated in the US, 17.2%, the result of this study seems to be in a resonable range.