• 한국광학회지
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• 제24권1호
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• pp.1-8
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• 2013

본 논문에서는 3차원 영상을 위한 LADAR(LAser Detection And Ranging)용 광검출기 모듈을 설계-제작하고 그 특성을 측정한 결과를 보고한다. 광검출기 모듈은 광파이버 어레이와 접속될 수 있도록 200 um 직경을 갖는 InGaAs APD(Avalanche Photodiode)로 설계-제작하였으며, 선형모드 동작 특성을 만족하도록 TIA(Trans-impedance Amplifier)를 설계-제작하였다. 광검출기 모듈을 구성하는 핵심부품들은 12개의 lead pin을 갖는 TO8 상에 집적되었으며, 집적에 필요한 APD 서브마운트 및 TIA 회로 등을 자체적으로 설계-제작하여 사용하였다. 제작한 광검출기 모듈은 450 ps의 rising time과 780 MHz의 대역폭 특성을 보였으며, 0.8 mV 이하의 잡음 특성과, 150 nW의 MDS(Minimum Detectable Signal) 신호 크기에 대해 15 이상의 신호대 잡음비(SNR)를 보임으로써 설계한 모든 특성을 만족하였는데, 이는 저자들이 아는 한 200 um 직경의 대면적 InGaAs APD를 이용한 광수신기에서 가장 우수한 특성을 나타낸 것이다.

• 융합보안논문지
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• 제6권3호
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• pp.79-86
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• 2006

본 논문에서는 광기전력 효과를 이용한 적외선 센서(SHARP사의 GP2D12)모듈의 거리에 따른 센서의 감도와 물체와 센서가 이루는 각도의 변화에 대한 센서의 감도를 측정하여 측정된 센서값을 블루투스를 이용해서 근거리에 있는 PC로 전송하고 전송된 값을 프로그램에 의하여 분석하였다. 분석한 결과 적외선 센서의 특성을 프로세서에서 바로 측정하였을 때와 측정된 값을 블루투스 통신을 이용하여 전송하였을 때 비교 값에 차이를 나타내지 않았다. 따라서 블루투스를 이용하여 100m이내의 근거리에 있는 물체를 적외선 센서로 측정 할 수 있음을 알 수 있었다.

• 동력기계공학회지
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• 제12권1호
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• pp.41-46
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• 2008

The primary objective of this study is to truly understand exciting forces of the in-line 4 cylinders engine. Exciting forces of the engine apply a source of the vehicle NVH(Noise, Vibration, Harshness). To understand exciting forces, first was governed theoretical equations for single cylinder engine. And this theoretical equations was programming using MATLAB software. To compare theoretical analysis value, was applied MSC.ADAMS software. To determined the specification of engine(2,000cc, in-line 4) was applied ADAMS/Engine module. And this specification for engine was applied ADAMS/View and MATLAB software. The geometry model for ADAMS/View analysis was produced by the 3-D design modeling software. After imported 3-D model, each rigid body was jointed suitable. Under idle speed for engine, was analysed. The results of analysis are fairly well agreed with those of three analysis method. Using MATLAB software proposed in this study, engine exciting fores can be predicted. Also using ADAMS/Engine module and ADAMS/View software, engine exciting forces can be predicted.

• ETRI Journal
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• 제34권2호
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• pp.216-225
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• 2012

This paper presents a transceiver module for human body communications whereby a spread signal with a group of 64 Walsh codes is directly transferred through a human body at a chip rate of 32 Mcps. Frequency selective digital transmission moves the signal spectrum over 5 MHz without continuous frequency modulation and increases the immunity to induced interference by the processing gain. A simple receiver structure with no additional analog circuitry for the transmitter has been developed and has a sensitivity of 250 ${\mu}V_{pp}$. The high sensitivity of the receiver makes it possible to communicate between mobile devices using a human body as the transmission medium. It enables half-duplex communication of 2 Mbps within an operating range of up to 170 cm between the ultra-mobile PCs held between fingertips of each hand with a packet error rate of lower than $10^{-6}$. The transceiver module consumes 59 mA with a 3.3 V power supply.

• 한국생산제조학회지
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• 제22권1호
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• pp.92-99
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• 2013

The ratio of mobility handicapped was 12,110,000 in late 2009 about 24.4% of total population. The number of handicapped population is increasing continuously due to traffic accidents and industrial disasters. Therefore, the purpose of this research is to suggest a design for passengers on wheelchairs to get into and off to raise handicapped or elderly people's right of mobility. The scope of this research is mobility handicapped especially wheelchair passengers who use vans, small buses, and trains. The ramp design of vans is module form. The ramp is moved with screw jack and guides are installed on each side to increase stability. Moreover, a bridge was installed for smooth getting in and off of the van. The ramp design for small bus is lowed by 200m in order not to have obstacle such as speed bump when getting in or off. In order to reduce vulnerable environment and administration, air slide cylinder was chosen. Lastly, for the ramp design of train, the principle of link was used that the simpler structure made the weight lighter and installation in the train became easier. If we look at the conjugation condition of heterogeneous materials to produce a ramp, proper welding condition for cold steel plate and stainless plate is 3kW output and 3-5m/min of welding speed using laser beam seems proper.

• Journal of Electrical Engineering and Technology
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• 제13권4호
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• pp.1638-1643
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• 2018

Multi-layer ceramic capacitors as decoupling capacitor were fabricated by dielectric composition with a high dielectric constant. The fabricated decoupling capacitors were embedded in the PCB of the 10G RF transceiver module and evaluated for the characteristics of electrical noise by the level of AC input voltage. In order to further improve the electrical properties of the $BaTiO_3$ based composite, glass frit, MgO, $Y_2O_3$, $Mn_3O$, $V_2O_5$, $BaCO_3$, $SiO_2$, and $Al_2O_3$ were used as additives. The electrical properties of the composites were determined by various amounts of additives and optimum sintering temperature. As a result of the optimized composite, it was possible to obtain a density of $5.77g/cm^3$, a dielectric constant of 1994, and an insulation resistance of $2.91{\times}10^{12}{\Omega}$ at an additive content of 5wt% and a sintering temperature of $1250^{\circ}C$. After forming a $2.5{\mu}m$ green sheet using the doctor blade method, a total of 77 layers were laminated and sintered at $1180^{\circ}C$. A decoupling capacitor with a size of $0.6mm(W){\times}0.3mm(L){\times}0.3mm(T)$ (width, length and thickness, respectively) and a capacitance of 100 nF was embedded using a PCB process for the 10G RF Transceiver modules. In the range of AC input voltage 400mmV @ 500kHz to 2200mV @ 900kHz, the embedded 10G RF Transceiver modules evaluated that it has better electrical performance than the non-embedded modules.

• 대한환경공학회지
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• 제34권12호
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• pp.792-800
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• 2012

본 연구는 남한강과 북한강 유역 내 경작지 각 3개소(site A, B, C)를 대상으로 Web GIS-based VFSMOD System의 HUFF & SCS UH-based VFS Design Module을 적용하여 강우 시 경작지에서 유출되는 고형물질 유출저감을 모의하였다. 북한강 유역 내에 위치한 site A의 노지 밭의 토지경사도 5%, 강우 106.2 mm 조건에서 고추 및 옥수수를 재배할 경우, 70% 이상의 고형물질 유출저감 효율을 얻기 위해서는 초생대 폭이 최소 0.5 m 이상, 토지경사도 10%인 경우 70% 이상의 고형물질 유출저감 효율을 얻기 위해서는 초생대 폭이 최소 1.0~1.5 m 이상 유지해야 한다. 남한강 유역 내에 site B의 노지 밭의 토지경사도 5%, 강우량 95.1 mm 조건에서 토마토 및 땅콩을 재배할 경우, 70% 이상의 고형물질 유출저감을 위해서는 초생대의 폭이 최소 0.5 m, 토지경사도 10%인 경우 50% 이상의 고형물질 유출저감을 위해서는 최소 1.0 m 이상의 폭을 갖는 초생대를 설치해야 하는 것으로 나타났다. 남한강 유역 내에 site C의 노지 밭의 토지경사도 5%, 강우량 102.6 mm 조건에서 고구마 및 콩을 재배할 경우, 64.0% 이상의 고형물질 유출저감을 위해서는 초생대의 폭이 최소 1.0 m, 초생대를 설치해야 하는 것을 분석되었다. 또한, 동일한 조건에서 강우지속시간 2시간의 강우량을 151.2 mm로 증가시킬 경우, 62.0% 이상의 고형물질 유출저감을 위한 초생대의 최소 폭은 1.0 m 이상 설치해야 하는 것으로 분석되었다. 초생대 시설은 경작지와 같은 토지이용 시 친환경적인 고형물질 유출저감 방안으로 검토될 수 있으며, Web GIS-based VFSMOD System을 이용하여 다양한 토지특성과 강우 사상을 반영하여 적정한 규모의 초생대 설계가 가능할 것으로 분석되었다.

• 대한공간정보학회지
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• 제11권1호
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• pp.3-12
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• 2003

하천유역의 수문학적 지형정보는 자료가 방대하여 이들을 획득하기 위해서는 많은 시간과 노력이 필요하였으며 현실적으로 사용이 곤란한 경우가 많다. 본 연구에서는 수자원의 효율적인 관리를 위한 수문정보 자료를 획득하기 위한 수단으로서 GIS를 이용하여 수문지형정보를 추출하기 위하여 DEM(Digital Elevation Model)의 처리방법을 기초로 한 GIS 소프트웨어인 Arc View를 이용하여 하천의 기하학적 요인 및 지형학적 특성을 정량화 하는 방법을 제시하며, CRID 모델을 이용하여 하천차수와 유역면적, 유역특성의 정량적 결과를 산출하는 것을 가능하게 했다. 총유로연장과 흐름누적셀 수의 관계식은 $Y=14632.87{\cdot}X^{-0.542444}$이며, 총유로연장과 셀크기의 관계식은 $Y=37014.1{\cdot}X^{-1.058808}$이다. 이들 식으로부터 탐진강 유역의 적정흐름누적셀의 수는 383개, 적정 셀의 크기는 44m임을 알 수 있었다.

• 한국군사과학기술학회지
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• 제12권4호
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• pp.452-459
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• 2009

A 6-bit MMIC digital attenuator applicable to X-band TR module has been developed by using $0.5{\mu}m$GaAs pHEMT processes. The Switched-T attenuator scheme and the switched-path attenuator scheme were adopted to obtain low insertion loss and small phase variation, respectively. Resistors and transmission lines are optimized to achieve the digital attenuator with high attenuation accuracy and small phase variation. The digital attenuator has RMS error of 0.4dB, resolution of 0.5dB and dynamic range of 31.5dB. The measurement results show that in-out VSWRs are less than 1.5, phase variation is from -7 to +2 degrees and IIP3 is 36.5dBm.

• Journal of Welding and Joining
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• 제21권2호
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• pp.97-101
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• 2003

The change of microstructures in the base metal during transient liquid phase bonding process of directionally Ni base superalloy, GID-111 was investigated. Bonds were fabricated using a series of holding times(0~7.2ks) at three different temperatures. The flip chip bonding utilizing self-aligning characteristic of solder becomes mandatory to meet tolerances for the optical device. In this paper, a parametric study of aging condition and pad size of samples was evaluated. A TiW/Cu/electroplated Cu UBM structure was selected and the samples were aging treated to analyze the effect of intermetallic compounds with the time variations. An FIB technique was applied to the preparation of samples for TEM observations. An FIB technique is very useful to prepare TEM thin foil specimens from the solder joint interface. After aging treatment, the tendency to decrease in shear strength was measured and the structure of the solder and the UBM was observed by using SEM, TEM and EDS. As a result, the shear strength was decreased of about 21% in the 100${\mu}{\textrm}{m}$ sample at 17$0^{\circ}C$ aging compared with the maximum shear strength of the sample with the same pad size. In the case of the 12$0^{\circ}C$ aging treatment, 18% of decrease in shear strength was measured at the 100${\mu}{\textrm}{m}$ pad size sample. An intermetallic compound of Cu6Sn5 and Cu3Sn were also observed through the TEM measurement by using.