• 한국군사과학기술학회지
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• 제17권6호
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• pp.764-772
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• 2014

The stealth performance of supersonic aircraft in recent air battlefield is one of the most significant feature for latest fighters. Especially, as the technology is advancing, the IR stealth capability becomes more important because of its passive characteristic. To design an aircraft with stealth capability, we must know how much the IR signature is generated from the aircraft. Also, predicting the IR signature of enemy's aircraft is tactically crucial. In this study, we calculated MWIR and LWIR infrared signature of $5^{th}$ generation supersonic aircraft against air-to-air and surface-to-air threat using IR simulation code and CFD coupled procedure.

• 한국주거학회논문집
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• 제27권6호
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• pp.113-124
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• 2016

The purpose of this study is to analyze characteristics of rental housing management and service preference according to social relationship types. The data for the analysis was collected through questionnaire survey method from 12th, April to 4th, May, 2016 and 565 data were finally used. Data were statistically analyzed using SPSS WIN 18.0. The findings of this study are as follows: 1) the six factors on social relations of subjects are made up as 'interpersonal stress of the relationship', 'new relationship', 'neighbor relations', 'online relationship', 'family relations', and 'friendship'. 2) Along with this result, cluster analysis was carried out, and four social relation types are classified and named as the 'extroverted relationship type', 'passive relationship type', 'active relationship type' and 'introverted relationship type'. 3) Rental housing management and service was examined separately as 'housing management system', 'housing services', and 'community facilities'. Differences in preference were identified by type of social relationship. Housing services and community facilities showed a significant difference in almost all items. In the housing management system, most of the items did not show any significant difference according to social relationship types.

• 조명전기설비학회논문지
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• 제13권2호
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• pp.17-23
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• 1999

이 논문에서는 현재 사용되고 있는 Dimming 형 IC의 특성에 최적인 전자식 안정기의 인버터내 회로상수를 결정하여 Dimming 형 전자식 안정기를 제작하였고, 제작된 안정기를 이용하여 형광램프의 전기적 특성과 광출력 특성을 비교하여 회로상수 선정법의 타당성을 증명하였다. 또한 제작된 Dimming 형 전자식 안정기를 마이크로프로세서를 이용하여 수동조작 뿐만 아니라 PC를 통한 원격자동제어가 가능하도록 하였고, 램프의 동작 상태, 주위 온도, 전자식 안정기의 이상유무를 PC의 화면상에 표시되도록 프로그램하여 원격제어시스템을 구축하였다.

• 한국전자파학회논문지
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• 제15권8호
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• pp.775-780
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• 2004

본 논문은, 각 채널이 여파기와 군지연 등화기로 구성되는, 위성용 다중채널 입력 멀티플렉서에서 사용되는 군지연-등화되는 여파기의, Simulated Annealing(SA) 기법과 Conjugate Gradient(CG) 기법의 새로운 결합형 설계 방식에 의한 구현을 기술한다. SA기법은 8차 타원적분형 여파기, CG기법은 2극 등화기 각각의 회로 설계변수들의 값을 찾아내는데 이용된다. 측정결과는 설계된 부품의 spec.에 대하여 성능이 만족함과 설계기법의 타당성을 나타낸다.

• 한국산업융합학회 논문집
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• 제9권1호
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• pp.29-35
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• 2006

The population of Daegu, the third biggest city in Korea, is two point six million. Daegu is known as a basin or a city where it is not only too hot in summer but also too cold in winter. Recently with redevelopment apartment house boom, a 40-story or more apartment complexes are under construction near Shin-cheon and Dondaegu-ro, the south-north axis of Daegu. It is necessary to raise several points about blocking a road of the wind by high-rise apartment buildings and apartment complexes. As a kind of the green policy, Daegu enlarge the distance between apartment building by reconstructing low-rise apartment into high-rise and impose a duty of a green space on the ground by making a parking zone into an underground. Through this process, apartment complexes changed from a '一'shape to a '口'shape. It increases heat island phenomenon of a city by blocking a road of the wind that comes from Shin-cheon and Dondaegu-ro. To circulate the polluted air of Daegu basin, we need local wind. There are four effective measures. 1) Throw three greens into one in the center of the road at the north side in the same way of the south side of Dongdaegu-ro, 2) reflect the information of roads of the wind including heights, spaces and directions of buildings, 3) steer clear of a high-rise buildings and development apartment house constructions, and 4)select a city for benchmarking to be the environmental capital.

• 한국정밀공학회지
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• 제23권3호
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• pp.125-131
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• 2006

Recently air pollution has become an important issue. So, as tile number of vehicles increases, the noise pollution has become one of the most serious social issues nowadays. It is a muffler, which is one of the vehicle components. that has the hugest impact on the noise from the vehicle. And it also has a direct influence on the engine performance. So lately the research is proceeding on tile semi-active muffler which can control the back pressure variably by setting up the exhaust variable valve in the baffle to improve its internal structure. The inner parts of muffler which consist of a baffle, pipes and etc. appear to have the complicated turbulence phenomena by the pulsational wave of an unsteady state in the engine and by the structural characteristics of the inner parts. To analyze these phenomena, it is required to have an analysis of its constant quantity and quality. Therefore this study is to analyze with PIV measurement which can analyze the time and space variables, not with the point measurement method like former multi-point anemometer. It is to suggest proper design variables which need to make internal structure of the muffler improve though comparison between the passive type muffler and the semi-active muffler by fabricating a muffler which can be visualized.

• Structural Monitoring and Maintenance
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• 제7권3호
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• pp.233-259
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• 2020

Using bonded fiber-reinforced polymer laminates for strengthening wooden structural members has been shown to be an effective and economical method. In this research, properties of suitable composite materials (sika wrap), adhesives and two ways of strengthening beams exposed to bending moment are presented. Passive or slack reinforcement is one way of strengthening. The most effective way of such a strengthening was to place reinforcement laminates in the stretched part of the wooden beam (lower part in our case), in order to investigate the effectiveness of externally bonding FRP to their soffits. The model is based on equilibrium and deformations compatibility requirements in and all parts of the strengthened beam, i.e., the wooden beam, the sika wrap composite plate and the adhesive layer. The theoretical predictions are compared with other existing solutions. This research is helpful for the understanding on mechanical behaviour of the interface and design of the composite-wooden hybrid structures. The results showed that the use of the new strengthening system enhances the performance of the wooden beam when compared with the traditional strengthening system.

• 유통과학연구
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• 제16권6호
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• pp.15-23
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• 2018

Purpose - This paper aims to explore the distribution and application of community-based disaster risk information and employ a case study as a qualitative research method to make some implications and suggestions for disaster management in the future. Research design, data, and methodology - This research has basically adopted an idiographic approaches to examine the basic policy of integrated flood risk management of Shiga prefecture in Japan. The methodology is based on a retrospective analysis, which starts from critical events and traces backwards processes to find out what goes well or wrong. Results - The results of this paper support that the multiple stakeholders in a community have to share and distribute disaster risk information in the proper time. The distribution and application of community-based disaster risk information cannot be overemphasized in that the local communities are culturally rich in traditional flood management knowledge, have voluntary organizations and have enjoyed mutual support and human network to cope with floods. Conclusions - The study results also imply that local residents of the community will be abe to have an important role in coping with natural disasters, which involves more proactive actions than passive actions for the enhancement of disaster management.

• KIEAE Journal
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• 제15권4호
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• pp.77-84
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• 2015

Purpose: In 2008, As the green growth policy was presented, Green Building is made any effort to propagation. In this paper, the respective technologies that are able to considerably reduce the energy demands for heating, cooling, hot-water, lighting and ventilation among the variety of technologies were selected. Method: Design factors such as (1) External insulation, (2) Triple glazing window, (3) LED lighting, (4) External venetian blind, (5) Geothermal and (6) Heat recovery ventilator were derived. In addition, energy saving effects in terms of energy demand, energy consumption and energy cost were investigated using EnergyPlus, building energy analysis tool. Result : The results were as follows. (1) It can be seen that high insulated triple glazing window, heat recovery ventilator and external insulation technology is excellent for energy demand. (2) Unlike energy demand, saving effect of energy consumption and energy cost was shown in order of Geothermal > Triple Window > Heat recovery Ventilation> Insulation> LED Lighting > EVB Blind.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.280-285
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• 2000

With recent development of technology of high stiffness material and the structural design, the construction of high rise structures such as tall building, tower has increased. The more flexible and slender structure is vulnerable to the internal and external dynamic loads induced by earthquake, wind and traffic load. There have been great effort and many researches to minimize the influence of dynamic loads on the structure. The traditional and stable method, the application of the passive damper, is not able to comply with various dynamic loads, while the mass damper which active control technology is integrated can effectively comply with load types. Therefore, the application of active control of huge structures with AMD(Active mass damper) or HMD(Hybrid Mass damper) is increasing. Up to now, most of actuators are servomotor and hydraulic actuator. But it is known that the electromagnetic actuator applies non contacting control force, which makes the control system easier with no characteristic change depending on time. In this paper, Hybrid mass damper with electromagnetic actuator was designed and applied to building scaled structure. The performance of designed HMD tested by shake table test is included.