• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2002년도 춘계학술대회논문집
• /
• pp.161-176
• /
• 2002

Collision avoidance is the most important part of a small vessel. Small and mediurn sized ships are surprisingly poor targets for radar reflection and are frequently in danger of being overrun by large vessels, even under good condition of visibility. One of the best way to prevent collisions at sea is to use as large and well designed a radar reflector. Thus, RCS(Radar Cross Section) increase is key element in the design of radar reflector. Radar Reflectors are normally classified into active-type and passive-type. In this paper, the RCS increase methods for passive-type reflector through shaping are explained, and analyzed with RCS performance test by computer simulation. As results from analysis, It is shown that the effective diameter of radar reflector is over 10 λ to provide a return above the threshold RCS of 25m$^2$, lower limit of detectability using X-band radar in a moderate sea.

• 한국생산제조학회지
• /
• 제26권2호
• /
• pp.185-192
• /
• 2017

In this paper, we reviewed major design parameters for a solid type of deployable antenna and its structural design. We performed modal analysis for a single reflector panel made of aluminum and CFRP (carbon fiber reinforced plastic) to confirm the appropriateness of selected materials. We then predicted the elastic modulus of CFRP using the principles of unidirectional composite elasticity stiffness predictions such as the ROM (Rule of Mixture) and HSR (Hart Smith 10% Rule). To optimize the shape of the antenna reflector, a structural stiffness analysis was performed using derived numerical optimization factors. Six structural stiffness analyses were performed using the constructed experimental design method. The resulting optimal shape conditions are proposed to meet the structural stiffness requirements while minimizing weight.

• 전기학회논문지P
• /
• 제58권3호
• /
• pp.347-350
• /
• 2009

In this study, it was studied about the improved road light design for drivers and pedestrians using forward or reverse ray-tracing method. Many of conventional road lights are not suitable for drivers and pedestrians because it has some serious problems such as glare effect or randomicity of illuminated areas. It was oriented from customary design method which was pointed at simple target such as luminance or electrical power. But it was not truth any more that the high luminance or electrical power consumption mean more bright and good road light. We studied ray-tracing method for road light reflector design to get the several goals. It means that good road light has easy for drivers and pedestrians eyes and illuminating objects on the road clearly. So, we set the design targets such as uniformity on the road area per one road light, shading angles and continuous luminance uniformity on the long distance road. We designed ideal road light conditions using ray-tracing method. We set the height of drivers and pedestrians eyes and calculated design guideline to make above design targets. Then we designed road light reflector using reverse ray-tracing method. And we achieved same luminance on the road almost half power consumption because we reduced loss of light. We achieved ideal design guide as 75 degrees of shading angles and 0.5 of luminance uniformity on the road area. It is superior than conventional road light ability such as 0.35 of luminance uniformity of 400 watts power consumption lamp. Finally, we suggested reflector design for 250 watts power consumption CDM Iight source.

• 한국전자통신학회논문지
• /
• 제9권1호
• /
• pp.97-104
• /
• 2014

최근에 열화상 카메라(적외선 카메라)는 수 변전 설비의 열화 상태를 진단하는데 많이 사용하고 있다. 그러나 자장이 높은 곳에서는 열화상 카메라의 전자부가 높은 자장으로 인하여 제대로 동작하지 못하는 문제점이 발생한다. 본 논문에서는 수 변전 설비 중 열화상 카메라의 동작에 영향을 주는 높은 자장을 발생시키는 정류기를 포함한 설비에서 적외선 카메라의 손상이 없이 열화진단을 수행할 수 있도록 반사경 설계 기법을 제안한다.

• 전기학회논문지
• /
• 제60권6호
• /
• pp.1178-1182
• /
• 2011

The best methods for distribution controled of LED lighting fixtures is control to designed LED chip array, lens and reflector. However, lens design need distribution design to reflector for low-wattage LED lighting because of difficulty of production and reduction of light efficiency. In addition, it needs maximize of thermal performance to improve the efficiency and reliability of device. As a result, for the height of reflector 40[mm] and Inclination 25[$^{\circ}$], we can see the best distribution properties, and, in the thermal properties, junction temperature MCPCB 62.9 [$^{\circ}C$], FR4 PCB 89.6 [$^{\circ}C$], FR4 PCB from Via-hole is 63.1 [$^{\circ}C$]. it may improve for thermal properties for makes the Via-hole.

• Journal of Electrical Engineering and Technology
• /
• 제10권4호
• /
• pp.1780-1785
• /
• 2015

In this paper, the adaptive particle swarm optimization (APSO) algorithm is employed to design a gain-enhanced antenna with a reflector for energy harvesting. We placed the reflector below the main radiating element. Its back-radiated field is reflected and added to the forward radiated field, which could increase the antenna gain. We adopt the adaptive particle swarm optimization (APSO) algorithm, which improves the speed of convergence with a high frequency solver. The result shows that performance of the optimized design successfully satisfied the design goal of the frequency band, gain and axial ratio.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2008년도 제39회 하계학술대회
• /
• pp.1497-1498
• /
• 2008

LED 조명기구의 최적 배광제어를 위한 방법으로 Reflector 와 Lens를 설계하여 빛을 제어한다. 그러나 Lens설계는 제작의 어려움과 광효율의 감소로 인하여 2차적으로 사용되는 방법이다. 이를 해결하기 위하여 본 논문에서는 Reflector를 이용한 배광 설계를 최적화하여 경제적인 제작이 가능 하도록 Photopia2.0을 이용하여 설계하였다. LED 각각의 개별 반사판과 모듈 전체 적용된 반사판을 적용하여 각 형태별 특징을 도출하였다.

• 한국광학회:학술대회논문집
• /
• 한국광학회 2006년도 하계학술발표회 논문집
• /
• pp.315-316
• /
• 2006

The modulation bandwidth, wavelength chirp of directly modulated coupled-ring reflector laser diode have been investigated using time-domain modeling. For a specific design, the modulation frequency could be 6 GHz and the frequency chirp could be in the range of $120^{\sim}200$ MHz/mA.

• 한국광학회지
• /
• 제30권5호
• /
• pp.197-203
• /
• 2019

본 논문은 광 소결 공정에 쓰이는 제논 플래시 램프 사용 시 조도 균일도를 개선시킬 수 있는 반사경 설계에 대한 연구를 진행하였다. 조사 영역에서 기판의 완전한 소결이 이루어지기 위해서 광효율과 조도 균일도를 목표 성능으로 설정하였다. 기존의 타원 반사경 또는 포물 반사경을 이용한 방식은 광효율을 만족하기 용이하지만 조도 균일도를 만족하는데 어려움이 있다. 따라서 본 논문에서는 조도 균일도를 만족시키기 위해 포물경의 중앙부에 쌍오목 형상을 추가하였다. 이러한 쌍오목 형태의 중앙부 형상을 갖는 포물 반사경의 조도 균일도가 기존의 반사경에 비해 향상됨을 확인하였다.

• 조명전기설비학회논문지
• /
• 제13권3호
• /
• pp.1-6
• /
• 1999

형광등용 조명기구에 사용되는 경명 반사판의 광학 설계 프로그램을 개발하였다. 이 프로그램은 조명기구 설계시간을 단축시킨다. SpeROD(Specular Reflector Optical Designer)는 2차원적인 조건들을 가지고 계산한다. 반사판 설계를 위해 고려되는 조건들은 목표배광, 반사판 그리고 Tangent Spiral Design 방법등이 있다. 본 논문에서는 SpeROD를 이용하여 지름 26mm(T8)의 형광램프와 폭 150mm의 반사판을 가지는 균일 배광 형태와 Bat-wing 배광형태의 반사판을 설계해보았다. 설계된 반사판의 형태에 대하여 배광에측 프로그램인 FIELD를 통하여 배광을 시뮬레이션 해 본 결과, 배광과 효율 면에서 만족스러운 결과를 얻었다.