• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1423-1426
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• 2005

Map building is the most important thing for the mobile robots navigation. It requires specific vision system such as CCD camera, range finding system, and many other things. Laser range finder has highly collimated beams can be obtained easily, thus achieving lateral resolution. Laser Diode is used for a continuous laser source. The Automatic Current Control Circuit and the Bias-T is used for mix AC signal with DC bias. This signal is used for driving Laser Diode. The main idea of the calculating distance is detecting phase shift between reference signal and detected signal by photo detector. For the signal processing, the Lock-in amplifier system is addressed in this paper. We used a diffused reflected beam to detect phase shift in this system. But this beam is minuteness signal so it can be easily buried in nose. Lock-in amplifier is used to measure the amplitude and phase of signals which are buried in noise.

• Structural Engineering and Mechanics
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• 제10권1호
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• pp.1-15
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• 2000

It is inevitable that every space truss structure would be under some form of direct member loading. At least the structure self weight certainly affects the members directly, and in structures involving top concrete slabs or cladding, their weight is also likely to apply some lateral pressure on the members. In spite of that, direct member loading is usually ignored in space truss designs and assumed to lead only to a negligible effect on truss performance. This study is intended to explore this point and identify the actual effects that can arise from direct member loading, and eventually provide an answer to the question of whether the current design practice is satisfactory or certain modifications would be needed. After presenting two analytical techniques to allow the study of space trusses with laterally loaded members, the paper describes a wide parametric study involving practical-size space trusses with different configurations, aspect ratios, boundary conditions and number of chord panels.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.223-228
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• 2003

Results of 61 framed reinforced concrete shear walls with openings were reviewed to evaluate the current design provisions for nominal shear strength. Provisions for ACI 318-02 and AIJ Code pertaining to shear design of shear walls evaluated the applicability of shear walls with openings subjected to lateral and vertical loads. Evaluation of test results indicates that the nominal unit shear strength($\Psi$=1.0) calculated using the provisions of ACI and AIJ does not represent the observed shear strength well. Based on the limited database considered in this study, A reasonable lower bound to the shear strength of high-strength concrete shear walls is found to be $1.09\sqrt{f_{cu}}$ kgf/$\textrm{cm}^2$.

• 전자공학회논문지A
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• 제29A권2호
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• pp.77-79
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• 1992

We propose a self-aligned and double recessed technique for GaAs power MESFETs application. The gate length and the wide recess width are defined by a selective removal of the SiN layer using reactive ion etching(RIE) while the depth of the channel is defined by chemical etching of GaAs layers. The threshold voltages and the saturation drain voltage could be sucessfully controlled using this technique. The lateral-etched distance increases with the dry etching time and the source-drain breakdown voltage of MESFET increases up to about 30V at a pinch-off condition. The electrical characteristics of a MESFET with a gate length of 2 x10S0-6Tm and a source-gate spacing of 33 x10S0-6Tm show maximum transconductance of 120 mS/mm and saturation drain current density of 170-190mA/mm at a gate voltage of 0.8V.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.192-197
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• 2001

To obtain $A_2$ experimentally in the $J-A_2$ theory, deformation field on the lateral surface of a CT specimen was to be determined using Laser speckle method. The crack growth was measured using direct current potential drop method and most procedure of experimental and data reduction was performed according to ASTM Standard E1737-96. Laser speckle images during crack propagation were monitored by two CCD cameras to cancel the effect of rotation and translation of the specimen. An algorithm to pursue displacement of a point from each image was developed and successfully used to measure $A_2$ continuously as the crack tip was propagated. The effects of specimen thickness on J-R curve and $A_2$ were explored.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2006년도 전기학술대회논문집
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• pp.301-302
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• 2006

초고주파 전력 증폭기의 바이어스 전압을 조절하여 온도 변화에 따른 드레인(Drain) 전류의 변화를 억제하기 위한 저가의 능동 바이어스 모듈을 개발한다. 능동 바이어스 모듈을 5 W급 초고주파 전력증폭기에 적용하였을 경우, $0{\sim}60^{\circ}C$까지의 온도변화에 대하여 소모전류 변화량은 0.1 A 이하로 되어야 한다. 본 기술 개발 대상인 능동 바이어스 모듈의 성능 시험을 위한 대상 전력증폭기는 $2.11{\sim}2.17GHz$ 주파수 대역에서 32 dB 이상의 이득과 ${\pm}0.1\;dB$ 이하의 이득 평탄도, -15 dB 이하의 입.출력 반사손실을 가진다.

• Structural Engineering and Mechanics
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• 제7권1호
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• pp.81-94
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• 1999

The dynamic analysis of trusses using the finite element method tends to overlook the effect of local member dynamic behavior on the overall response of the complete structure. This is due to the fact that the lateral inertias of the members are omitted from the global inertia terms in the structure mass matrix. In this paper a condensed dynamic stiffness matrix is formulated and used to calculate the exact dynamic properties of trusses without the need to increase the model size. In the examples the limitations of current solutions are presented together with the exact results obtained from the proposed method.

• 해양환경안전학회지
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• 제8권2호
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• pp.45-52
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• 2002

Recently there have been growing disputes between neighboring local governments over jurisdictional rights or property rights of ocean resources in Korean coastal waters. The reasons for the disputes come mainly from the increasing interests by local governments that begin to see the oceans as the source of resources and wealth. The maritime dispute is more complicated and sticky than the inland ones, and requires not only socio-economical but political approach, therefore sometimes demanding a plenty of time and endeavor. Also coastal states that have suffered from maritime boundary problems have different issues under the different environment and historical background. For Korea, as the maritime boundary issue has very recently soared to the surface, though it was latent for the period as long as 20 years, we have just taken steps toward an institutional approach on it, seemingly more to go to reach an agreeable resolutions to the disputes. This paper highlighted the issues surrounding the maritime boundary on the sea surrounding Korean peninsular after addressing the current situation of the boundary disputes. It will help explore and assess the possible solutions to the boundary conflicts over the lateral boundary between local governments.

• JSTS:Journal of Semiconductor Technology and Science
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• 제15권2호
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• pp.286-291
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• 2015

For highly scalable NAND flash memory applications, a compact ($4F^2/cell$) nonvolatile memory architecture is proposed and investigated via three-dimensional device simulations. The back-channel program/erase is conducted independently from the front-channel read operation as information is stored in the form of charge at the backside of the channel, and hence, read disturbance is avoided. The memory cell structure is essentially equivalent to that of the fully-depleted transistor, which allows a high cell read current and a steep subthreshold slope, to enable lower voltage operation in comparison with conventional NAND flash devices. To minimize memory cell disturbance during programming, a charge depletion method using appropriate biasing of a buried back-gate line that runs parallel to the bit line is introduced. This design is a new candidate for scaling NAND flash memory to sub-20 nm lateral dimensions.

• 한국지반공학회논문집
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• 제20권6호
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• pp.119-126
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• 2004

본 논문에서는 현장계측을 통해 관측된 소일네일링 벽체의 거동을 분석하였다. 연구의 주요내용으로는 인발시험을 통해 산정한 네일과 지반의 경계면에서 전단강도의 발생, 지반의 수평변위, 네일에 발생하는 인장력의 분포 및 경계면에서의 전단강도의 발현 등이다. 특히, 경계면에서의 전단응력 발생 과정 및 전단강도 발현에 대한 심도있는 분석을 실시하였다. 본 연구에서 분석된 자료는 국내 소일네일링의 예비설계 단계시 참고 자료로 활용될 수 있을 것으로 기대된다.