• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1523-1524
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• 2011

• Aerospace Engineering and Technology
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• v.9 no.2
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• pp.161-167
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• 2010

CEU(Camera Electronic Unit) loaded in optical satellite for a high resolution image acquisition is composited with CC(Camera Controlloer), FPA(Focal Plane Assembly) and CEUP(CEU Power supply). EMC test and analysis results are explained in this paper. CE, CS, RE and RS test is performed in the 1st EMC test, RE, RS test which is not complied and influence considerably after shielding structure is performed in the 2nd EMC test. An effect due to the noise of CEU in the GPS/S-band receiving band is analyzed based on 2nd EMC test results. Margin more than 6dB is guaranteed when CEU is shielded.

• Journal of Korea Multimedia Society
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• v.13 no.11
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• pp.1575-1585
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• 2010

It is very important to forecast a back resource of a software development effort at the early stage of development life cycle for successful project processing, and it is carried out through software size estimation. The recent trend of software size estimation method is focused on the user's value such as FPA. We measure the actual development effort through case study and calculate CFP directly according to the cosmic-ffp manual V.3.0. in this paper. We also propose the software development effort estimation model by using the produced data. COSMIC-FFP does not use weights of necessary function elements, and so it has disadvantage in estimating sizes. This paper proposes the estimation model to estimate the precision software size by using system complexity as weight.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.42 no.3
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• pp.45-50
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• 2005

A UV camera is being used in various application regions such as industry, medical science, military, and environment monitoring. A ROIC(ReadOut IC) is developed and can read the responses from UV photodiode sensors which are made with III-V nitride semiconductors of GaN series haying high resolution and high efficiency. To design FPA(Focal Plane Array) UV $8{\times}8$ ROIC, the photodiode type sensor devices are modeled as the capacitor type ones. The ROIC reads out signals from the detector at)d outputs sequentially pixel signals after amplifying and noise filtering of them. The ROIC is fabricated using the $0.5{\mu}m$ 2Poly 3Metal N-well CMOS process. And then, it and photodiode array are hybrid bonded by gold stud bumping process using ACP(Anisotropic Conductive Paste). After the packaging, UV images appearing on PC verified the operations of the ROIC.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.53.2-53.2
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• 2014

IGRINS, the Immersion GRating INfrared Spectrometer, is a near-infrared wide-band high-resolution spectrograph jointly developed by the Korea Astronomy and Space Science Institute and the University of Texas at Austin. IGRINS employs three HAWAII-2RG focal plane array (FPA) detectors. The mechanical mounts for these detectors serves a critical function in the overall instrument design: Optically, they permit the only positional compensation in the otherwise "build to print" design. Thermally, they permit setting and control of the detector operating temperature independently of the cryostat bench. We present the design and fabrication of the mechanical mount as a single module. The detector mount includes the array housing, a housing for the SIDECAR ASIC, a field flattener lens holder, and a support base. The detector and ASIC housing will be kept at 65 K and the support base at 130 K. G10 supports thermally isolate the detector and ASIC housing from the support base. The field flattening lens holder attaches directly to the FPA array housing and holds the lens with a six-point kinematic mount. Fine adjustment features permit changes in axial position and in yaw and pitch angles. We optimized the structural stability and thermal characteristics of the mount design using computer-aided 3D modeling and finite element analysis. Based on the computer simulation, the designed detector mount meets the optical and thermal requirements very well.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.11
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• pp.7-13
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• 2002

BSCT 320${\times}$240 IRFPA detector module is implemented, which is a key component in uncooled thermal imaging systems. The detector module consists of two parts, infrared sensitive pixel array and read-out integrated circuit(ROIC). The BSCT 320${\times}$240 pixels are made by laser scribe process and 10-${\mu}m$ micro-bump to satisfy 50-${\mu}m$ pitch and 95-% fill-factor. The ROIC has been designed to electrically address the pixels sequentailly and to improve signal-to-noise ratio with single transistor amplifier, HPF, tunable LPF and clamp circuit. The fabricated hybrid chip of detector and ROIC has been mounted on the TEC built-in ceramic package for more stable operation and tested for lots of electrical and optical properties. The IRFA sample has shown successful properties and met with good results of fill-factor, detectivity and responsivity.

• Journal of Sensor Science and Technology
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• v.24 no.6
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• pp.379-384
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• 2015

An infrared image sensor is a core device in a thermal imaging system. The fabrication method of a focal plane array (FPA) is a key technology for a high resolution infrared image sensor. Each pixels in the FPA have $Si_3N_4/SiO_2$ membranes including legs to deposit bolometric materials and electrodes on Si readout circuits (ROIC). Instead of polyimide used to form a sacrificial layer, the feasibility of an amorphous silicon (${\alpha}-Si$) was verified experimentally in a $8{\times}8$ micro-bolometer array with a $50{\mu}m$ pitch. The elimination of the polyimide sacrificial layer hardened by a following plasma assisted deposition process is sometimes far from perfect, and thus requires longer plasma ashing times leading to the deformation of the membrane and leg. Since the amorphous Si could be removed in $XeF_2$ gas at room temperature, however, the fabricated micro-bolomertic structure was not damaged seriously. A radio frequency (RF) sputtered nickel oxide film was grown on a $Si_3N_4/SiO_2$ membrane fabricated using a low stress silicon nitride (LSSiN) technology with a LPCVD system. The deformation of the membrane was effectively reduced by a combining the ${\alpha}-Si$ and LSSiN process for a nickel oxide micro-bolometer.

• Journal of the Korean Institute of Intelligent Systems
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• v.10 no.5
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• pp.409-416
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• 2000

In the shared-memory mutiprocessor systems, shared processing techniques such as time-sharing, space¬sharing, and gang-scheduling are used to improve the overall system utilization for the parallel operations. Recently, LLPC(Loop-Level Process Control) allocation technique was proposed. It dynamically adjusts the needed number of processors for the execution of the parallel code portions based on the current system load in the given job. This method allocates as many available processors as possible, and does not save any processors for the parallel sections of other later-arriving applications. To solve this problem, in this paper, we propose a new processor allocation technique called FPA(Fuzzy Processor Allocation) that dynamically adjusts the number of processors by fuzzifYing the amounts ofueeded number of processors, loads, and estimated execution times of job. The proposed method provides the maximum possibility of the parallism of each job without system overload. We compare the performances of our approaches with the conventional results. The experiments show that the proposed method provides a better performance.

• Journal of Veterinary Clinics
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• v.39 no.3
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• pp.93-99
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• 2022

The present study was performed to compare cranial tibial wedge osteotomy (CTWO) and tibial plateau leveling osteotomy (TPLO) through radiographic evaluation. The experiment was conducted with five cadaver dogs [mean (± SD) weight, 32.9 ± 4.1 kg; mean (± SD) age, 6 ± 2 years; three males and two females] euthanized for reasons unrelated to this study. The cadaver dogs consisted of German Shepherd (n = 3), Belgian Malinois (n = 1), and mixed breed (n = 1). CTWO and TPLO were carried out by the standard surgical method. Radiographic evaluation was performed by comparing several factors, including the flexion and extension angles, the anatomical mechanical axis angle (AMA-angle), tibial length, patellar height measurement using the Labelle-Laurin method, mechanical medial proximal tibial angle (mMPTA), mechanical medial distal tibial angle (mMDTA), and frontal plane alignment (FPA). Both the CTWO and the TPLO groups showed significantly increased flexion angles after surgery. Only the CTWO group had significantly increased extension angle. Although both groups showed significant decreases in the AMA-angle, the mechanical axis moved cranially against the anatomical axis only in the CTWO group. The patellar height was significantly lowered in the CTWO group. No significant differences were found in mMPTA, mMDTA, or FPA. In conclusion, radiographic comparison revealed more changes in CTWO group than in TPLO group.

• Broadcasting and Media Magazine
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• v.16 no.2
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• pp.63-72
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• 2011

디지털 홀로그래피는 가간섭성 광원을 이용하여 광파의 위상 정보를 기록 또는 재생하는 기술이다. 이러한 홀로그래피 방식의 광파 재생은 광파를 산란시키는 3차원 대상물을 정확하게 표현할 수 있어서 이상적인 디스플레이 방법으로 여겨진다. 디지털 홀로그래피에서 광파의 샘플링 영역과 그 대역폭의 곱은 공간 대역폭으로 정의되며, 이러한 공간 대역폭은 디지털 홀로그래픽 시스템의 능력을 나타내는 가장 기본적인 수치이다. 공간 대역폭은 샘플링 개수로 이해될 수 있으며 이는 focal plane array (FPA)나 spatial light modulator (SLM)의 픽셀 개수와 일치한다. 디지털 홀로그래피 기술로 기존의 디스플레이가 가지는 크기와 시야각 수준의 광파를 표현하고자 한다면 매우 큰 공간 대역폭이 요구된다. 따라서 디지털 홀로그래픽 디스플레이 시스템의 공간 대역폭을 늘리기 위한 방법은 꾸준히 연구되어 오고 있으며 최근 주목할 만한 시스템들이 제안되었다. 공간 대역폭에 대한 이해를 바탕으로 SLM을 이용한 홀로그래픽 디스플레이에서 가시 부피와 해상도에 대해 논하고, 최근 주목 받고 있는 홀로그래픽 디스플레이의 공간 대역폭을 정리하였다.