• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2000.06a
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• pp.132-132
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• 2000

• Proceedings of the Korean Society of Crop Science Conference
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• 2001.05a
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• pp.208-209
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• 2001

• 한국약용작물학회:학술대회논문집
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• 2012.05a
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• pp.335-336
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• 2012

• 한국약용작물학회:학술대회논문집
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• 2012.05a
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• pp.289-290
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• 2012

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.8
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• pp.1968-1973
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• 2013

We present the enhancement of narrowband modulation response of an optical source by integrating a dual-electrode distributed feedback (DFB) laser with an electro-absorption modulator (EAM). The dual-electrode DFB laser exhibits a multiple optical modes owing to a self-pulsation in GHz range. By modulating the laser and modulator sections of the integrated device simultaneously, 20-dB of narrowband modulation response enhancement at 6 GHz with 7-GHz tuning range has been observed.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.5 s.57
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• pp.142-148
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• 2009

This paper is to investigate the fracture behavior characteristics of box culvert and incremental crack width of upper slab for the incremental loading by the 3-axis loading system. In the 3-axes loading system, loading directions are upper side, left and right side which simulate earth pressure and static traffic load. With the incremental load, crack patterns is investigated on the upper slab, left and right wall. Especially, on the upper slab, crack width is measured by crack gage. Based on the experimental results, structural internal force indices of box culvert are estimated quantitatively.

• Proceedings of the Materials Research Society of Korea Conference
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• 2000.11a
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• pp.167-167
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• 2000

• Journal of Drive and Control
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• v.1 no.3
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• pp.26-31
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• 2004

• The Korean Journal of Nuclear Medicine
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• v.38 no.1
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• pp.74-84
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• 2004

Purpose: Since I-125 emits low energy (27-35 keV) radiation, thinner crystal and collimator could be employed and, hence, it is favorable to obtain high quality images. The purpose of this study was to derive the optimized parameters of I-125 SPECT using a new simulation tool, GATE (Geant4 Application for Tomographic Emission). Materials and Methods: To validate the simulation method, gamma camera developed by Weisenberger et al. was modeled. Nal(T1) plate crystal was used and its thickness was determined by calculating detection efficiency. Spatial resolution and sensitivity curves were estimated by changing variable parameters for parallel-hole and pinhole collimator. Peformances of I-125 SPECT equipped with the optimal collimator were also estimated. Results: in the validation study, simulations were found to agree well with experimental measurements in spatial resolution (4%) and sensitivity (3%). In order to acquire 98% gamma ray detection efficiency, Nal(T1) thickness was determined to be 1 mm. Hole diameter (mm), length (mm) and shape were chosen to be 0.2:5:square and 0.5:10:hexagonal for high resolution (HR) and general purpose (GP) parallel-hole collimator, respectively. Hole diameter, channel height and acceptance angle of pinhole (PH) collimator were determined to be 0.25 mm, 0.1 mm and 90 degree. The spatial resolutions of reconstructed image of the I-125 SPECT employing HR:GP:PH were 1.2:1.7:0.8 mm. The sensitivities of HR:GP:PH were 39.7:71.9:5.5 cps/MBq. Conclusion: The optimal crystal and collimator parameters for I-125 Imaging were derived by simulation using GATE. The results indicate that excellent resolution and sensitivity imaging is feasible using I-125 SPECT.

• Defense and Technology
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• no.5 s.123
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• pp.38-45
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• 1989

북한은 현재 완전한 선진 군수산업을 이루고 있다. 한때 재원 부족으로 어려움을 겪기도 하였으나, 개량형 Scud미사일 개발을 추진해 오고 있으며, 이란의 대규모 무기구매로 재정적인 어려움이 풀린 것으로 보인다. 그러나 장비가 정교하지 못하며, 최신의 사격통제 및 포 조준 컴퓨터나 대공사통장비등의 생산을 도와줄 전자산업의 낙후가 문제로 남아 있다. 이것은 군수산업에서의 중요한 결함이다