• 천문학회보
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• 제41권2호
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• pp.39.1-39.1
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• 2016

We report the discovery of a kiloparsec-size supershell in the outskirts of the Milky Way with the compact high-velocity cloud, HVC 040+01-282 (hereafter, CHVC040), at its geometrical center using the "Inner-Galaxy Arecibo L-band Feed Array" HI 21 cm survey data. Supershells are large gaseous shells, which could be produced by one of most energetic activities with an explosion energy more than $3{\times}1052erg$. The most promising origin is the explosion of multiple supernovae in OB associations, or alternatively, the impact of HVCs falling into the Galactic disk. We found the association between CHVC040 and the Galactic supershell by analysis of their morphological and physical properties. Our results imply that some compact HVCs can survive their trip through the Galactic halo and inject energy and momentum into the Milky Way disk.

• International Journal of Precision Engineering and Manufacturing
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• 제8권3호
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• pp.64-70
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• 2007

Of all the rapid tooling (RT) methods currently available, thick-layer laminated tooling is the most suitable for large-scale, low-cost dies and molds. Currently, the determination of a lamina's contour or profile and the associated slicing algorithms are based on existing rapid prototyping (RP) data manipulation technology. This paper presents a new adaptive slicing algorithm developed exclusively for profiled edge laminae (PEL) tooling PEL tooling is a thick-layer RT technique that involves the assembly of an array of laminae, whose top edges are simultaneously profiled and beveled using a line-of-sight cutting method based on a CAD model of the intended tool surface. The cutting profiles are based on the intersection curve obtained directly from the CAD model to ensure geometrical accuracy. The slicing algorithm determines the lamina thicknesses that minimize the dimensional error using a new tool shape error index. At the same time, the algorithm considers the available lamination thicknesses and desired lamina interface locations. We demonstrate the new slicing algorithm by developing a simple industrial PEL tool based on a CAD part shape.

• 에너지공학
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• 제24권4호
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• pp.159-165
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• 2015

본 논문에서는 EMP 차폐를 위한 WBC 배열이 설치된 대형 비상발전기 연도의 최적형상을 결정하는 것을 목표로 연구를 진행하였다. 시뮬레이션은 WBC 배열의 외부관경이 800, 850, 900, 1050mm 및 1250mm를 대상으로 하였으며 기본연도와의 접속길이를 150, 300, 450 mm, 연도의 유속은 15, 20, 25m/s로 하였다. EMP 차폐를 위한 WBC 배열을 연도에 설치하는 경우 WBC 배열의 외부관경, Main 연도와의 접속길이가 배기가스 흐름에 큰 영향을 미치는 것으로 나타났다. WBC 배열의 외부관경이 1050, 1250mm이고 접속길이가 300, 450mm이면 도파관 배열에서 배기가스의 평균속도와 최고속도를 만족시키는 것으로 나타났다.

• 한국가구학회지
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• 제25권3호
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• pp.165-172
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• 2014

3D form study is one of basic subjects in industrial design education. There are an array of textbooks of visual art, design and architecture, most of which address basic geometrical form study and abstract forms. With the introduction of computerization, current trends are directed to reduce basic form education and students' participation in classes and their accomplishments. This study was intended to develop works under a theme of furniture design with concrete shapes and functions. This study focused on developing relevant process by fusing 3D form study and furniture design which fall into basic design and design studio subjects, respectively. Among 3D form studies, applied were a concept of 3D configuration that explores the relations between surface forms and 3D forms. Furniture design is a challenge to students at beginner or intermediate level in basic design education from initial devising stage to production in kind. To ease high level of difficulties at designing and producing stages, technical education was systematized in the process of conceptualizing, developing idea and production. This type of challenge was carried out during separate semesters, along with a case study done to develop different types of challenges. This study helped students to be motivated and actively participate in classes and well perform advanced form study and technical training from design to actual production.

• 대한전자공학회논문지SD
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• 제37권9호
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• pp.38-46
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• 2000

본 논문에서는 신뢰성이 높고, 효율적으로 최적해에 도달하는 GA 학습기법을 광 연결에 응용하기 위한 소자 설계에 적용하였다. 실시간에 가까운 광 신호 처리를 위해 프로그래머블 SLM에 CGH 공간 필터를 입력하여 복합 광 신호 처리 시스템을 구성하여 실험하였다. 광학 실험에 의해 실제로 CCD 배열 검출기에서 얻어진 스폿 빔을 정략적인 데이터로 측정하기 위해 기하학적인 변형을 수행한 결과, $3{\times}3$ 스폿 빔에 대하여 그레이 레벨로서 스폿 빔들의 평균이 202, 최대값이 225, 최소값이 186으로 얻어졌고, 균일도가 $1.93{\times}10^{-1}$ 로서 시뮬레이션 결과와 유사하게 안정된 분포로 출력되었다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(5)
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• pp.93-96
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• 2001

Tactile display devices use an array of pins mounted in the form of a matrix to present three-dimensional shapes to the user by raising and lowering. With a denser matrix of mounted pins, it can be expected that shape identification will be become easier and the time required for identification will also become shorter, but that problems of difficulty in fabrication will arise. It is necessary to consider such trade-offs in the development of such devices. This study conducted experiments to study the effect of pin pitch on shape identification as Part of the fundamental investigation of this subject. The experiment used three tactile display devices with pin pitches of In, 2mm and 3mm for geometrical shape identification, with response time and rate of misidentification taken as the performance data. Surfaces, edgs and vertices of three-dimensional shapes were used as the shape primitives for displayed shapes and several of each type were selected for presentation. The results obtained revealed that performance has different relationships to pin pitch with different shape primitives.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.388-391
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• 2003

The properties of these detectors can be controlled by electronics and exposure conditions. Flat-panel detectors for digital diagnostic imaging convert incident x-ray images to charge images. Flat panel detectors gain more interest real time medical x-ray imaging. Active area of flat panel detector is $14{\times}17$ inch. Detector is based on a $2560{\times}3072$ away of photoconductor and TFT pixels. X-ray conversion layer is deposited upper TFT array flat panel with a 500m by thermal deposition technology. Thickness uniformity of this layer is made of thickness control technology(5%) of thermal deposition system. Each $139m{\times}139m$ pixel is made of thin film transistor technology, a storage capacitor and charge collection electrode having geometrical fill factor of 86%. Using the separate driving system of two dimensional mosaic modules for large area, that is able to 4.2 second per frame. Imaging performance is suited for digital radiography imaging substitute by conventional radiography film system..

• Journal of Radiation Protection and Research
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• 제3권1호
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• pp.29-32
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• 1978

감마선을 방출(放出)하는 방사성발기물(放射性發棄物)드럼 5292개($42{\times}42{\times}3$) 저장시설(貯藏施設)의 적정(適正) 콘크리트 차폐체(遮蔽體) 두께를 산출(算出)하였다. 발기물(發棄物)이 여러가지 종류(種類)의 방사성원소(放射性元素)로 구성(構成)되어 있다고 할때 평균(平均)한 감마선 에너지와 개개(個個) 감마선 에너지에 대하여 계산(計算)한 결과(結果)를 서로 비교(比較)하였다. 그 결과(結果) 적정차폐체(適正遮蔽體)의 두께는 50cm 정도(程度)로 판명(判明)되었다. 그런데 평균(平均) 감마선 에너지에 근거(根據)하여 계산(計算)한 선량치(線量値)는 개개(個個) 감마선 에너지에 대한 값보다 동일(同一)두께의 차폐체(遮蔽體)에 대해서 훨씬 적었다.

• Journal of Ship and Ocean Technology
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• 제8권3호
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• pp.18-25
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• 2004

Sound reception system is required to detect the sound and the quadrantal direction of the other ship's horn sound, to overcome the effects of enclosed wall for navigation space, functioning as a sound barrier. However, the realized systems can only provide quadrantal information of the other ship. This paper presents a new arrangement of microphones, having geometrically symmetric deployment with the same distances between sensors and the same angles between adjacent sensors with respect to the geometrical center. The sound pressures received at microphones are transformed into the related envelope signals by applying Hilbert transform. The time delays between microphones are estimated by the correlation functions between the derived envelope signals. This envelope base processing mitigates the noises related to the reflection by ship and sea surface. Then, the directional information is easily defined by using the estimated time delays. The suggested method is verified by the generated signals using boundary element method for a small ship model with sea surface wave. The estimated direction is quite similar to the true one and therefore the proposed approach can be used as an efficient sound reception system.

• Advances in aircraft and spacecraft science
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• 제10권1호
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• pp.67-82
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• 2023

Linear array imaging sensors are widely used in remote sensing satellites. The final products of an imaging sensor can only be used when they are geometrically, radiometrically, and spectrally calibrated. Therefore, at the first stages of sensor design, a detailed calibration procedure must be carefully planned based on the accuracy requirements. In this paper, focusing on inherent optical distortion, a step-by-step procedure for laboratory geometric calibration of a typical push-broom satellite imaging sensor is simulated. The basis of this work is the simulation of a laboratory procedure in which a linear imager mounted on a rotary table captures images of a pin-hole pattern at different angles. By these images and their corresponding pinhole approximation, the correction function is extracted and applied to the raw images to give the corrected ones. The simulation results illustrate that using this approach, the nonlinear effects of distortion can be minimized and therefore the accuracy of the geometric position of this method on the image screen can be improved to better than the order of sub-pixel. On the other hand, the analyses can be used to proper laboratory facility selection based on the imaging sensor specifications and the accuracy.