• Journal of the Korean Society for Precision Engineering
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• v.16 no.2 s.95
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• pp.176-182
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• 1999

This paper presents a new autonomous kinematic calibration technique by using a laser-vision sensor called "Perceptron TriCam Contour". Because the sensor measures by capturing the image of a projected laser line on the surface of the object, we set up a long, straight line of a very fine string inside the robot workspace, and then allow the sensor mounted on a robot to measure the point intersection of the line of string and the projected laser line. The point data collected by changing robot configuration and sensor measuring are constrained to on a single straght line such that the closed-loop calibration method can be applied. The obtained calibration method is simple and accurate and also suitable for on-site calibration in an industrial environment. The method is implemented using Hyundai VORG-35 for its effectiveness.

• Journal of the Korean Society of Industry Convergence
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• v.5 no.2
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• pp.141-146
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• 2002

Stereolithography is the best known as rapid prototyping system. It uses the STL format data which is generated from CAD system. In this study, One of the main function of this developed CAM system deals with shape modification which divide a shape into two parts or more. The cross section of a STL part by a z-level is composed with nested or single polygonal closed loop. In order to make RP product, closed loops must fill with triangular facets from SSET and recover sliced triangular facets which is located normal direction to the cross sectional plane. The system is development by using Visuall C++ compiler in the environment of pentium PC. Operating system is Windows NT workstaion from Micro-Soft.

• Structural Engineering and Mechanics
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• v.16 no.1
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• pp.101-114
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• 2003

A base isolation system is proposed for earthquake protection of structures. The system incorporates spherical supports for the base, a specially designed spring-cam system to keep the base rigidly supported under normal condition and to allow it to move for the duration of the earthquake under the constraint of a spring with optimized non-linear characteristics. A single-story model is constructed to investigate the feasibility of the concept. Numerical simulations of the system as well as experimental results show that 95% reduction of the transmitted force to the structure can be achieved. To demonstrate the effectiveness of this isolation mechanism, the maximum dynamic bending stress developed at predetermined critical points within the frame of the structure is measured. Significant reduction of the dynamic stresses is obtained.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.1
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• pp.9-14
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• 1997

The pump-pipe-injector system is that most commonly used type of injection equipment for diesel engines. In this study, a new electromagnetic fuel injection system was designed and carried out the experiment of single cylinder direct injection(DI) diesel engine. This system do not need the cam shaft for fuel injection. The effects of the injection timing on the combustion process and emission were investigated. The results are that 1) atomization was improved, 2) combustion pressure was increased and ignition delay became shorter than before, 3) Low smoke level guarantee with more advanced injection timing without abnormal combustion but NOX concentration was increased as the injection time advanced.

• International Journal of CAD/CAM
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• v.9 no.1
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• pp.55-60
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• 2010

Quadratic B$\acute{e}$zier curves are important geometric entities in many applications. However, it was often ignored by the literature the fact that a single segment of a quadratic B$\acute{e}$zier curve may fail to fit arbitrary endpoint unit tangent vectors. The purpose of this paper is to provide a solution to this problem, i.e., constructing $G^1$ quadratic B$\acute{e}$zier curves satisfying given endpoint (positions and arbitrary unit tangent vectors) conditions. Examples are given to illustrate the new solution and to perform comparison between the $G^1$ quadratic B$\acute{e}$zier cures and other curve schemes such as the composite geometric Hermite curves and the biarcs.

• Bulletin of the Korean Chemical Society
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• v.34 no.10
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• pp.3022-3026
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• 2013

The adsorption of carbon dioxide on graphene sheets was theoretically investigated using density functional theory (DFT) and MP2 calculations. Geometric parameters and adsorption energies were computed at various levels of theory. The $CO_2$ chemisorption energies on graphene-$C_{40}$ assuming high pressure are predicted to be 71.2-72.1 kcal/mol for the lactone systems depending on various C-O orientations at the UCAM-B3LYP level of theory. Physisorption energies of $CO_2$ on graphene were predicted to be 2.1 and 3.3 kcal/mol, respectively, at the single-point $UMP2/6-31G^{**}$ level of theory for perpendicular and parallel orientations.

• Magazine of the Korean Society of Agricultural Engineers
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• v.40 no.1
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• pp.96-105
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• 1998

Soil properties, drain conditions and numerical analysis technique have great influence upon consolidation behavior. In relevant to the above described fact, this paper aims to examining the applicability of prediction model of consolidation as well as deformation characteristics for soft clayey foundation improved by sand drain. A case study for actual foundation of Kwangyang steel works was performed. Single drain consolidation model proposed by Hansbo and Biot's consolidation theory coupled with modified Cam-clay model developed during the research were employed for the FEM numerical analysis of the foundation. Both smear effect and drain capacity were taken into account for the analysis. Finally the applicability of the newly developed technique to the behavior of foundation composed of soft clay proved satisfactory.

• ETRI Journal
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• v.28 no.3
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• pp.401-404
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• 2006

A new log-domain first-order multifunction filter is proposed in this letter. The proposed filter is systematically derived using the state-space synthesis procedure from a corresponding block diagram. It provides low-pass (LP), high-pass (HP), and all-pass (AP) responses simultaneously for a single input signal. The filter circuit has a very simple structure since it uses only bipolar junction transistors (BJTs) and a grounded capacitor. It can be electronically tuned by changing an external current. The filter has a greater bandwidth due to its inherent current-mode and log-domain operations. PSPICE simulations are given to confirm the theoretical analysis.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.718-720
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• 2022

신뢰할 수 있는 딥러닝 기반 영상처리 기술을 적용하여 도서관 등 공공장소에서 별도의 센서 없이 하나의 카메라로만 좌석의 점유 사항을 자동으로 검출하여 사용자에게 앱으로 제공하는 솔루션을 제안한다. 라즈베리파이를 이용하며 촬영과 동시에 내부적으로 분석 및 좌석탐지가 진행되며, 촬영된 데이터는 모두 탐지 즉시 휘발된다. 이로 인해 우리의 솔루션은 구조적으로 개인정보 유출 등의 민감한 데이터는 유출될 우려가 없다. 또한 탐지가 완료된 후 결과를 서버로 전송하기 때문에 서버의 처리량이 크게 감소된다. 우리는 이와 같이 신뢰할 수 있고 효율적으로 좌석을 탐지하고 정보를 제공하는 솔루션을 제안한다.

• Journal of Life Science
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• v.22 no.7
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• pp.863-870
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• 2012

Rhodopsin, a dim light photoreceptor, has been regarded as one of the model systems for the structural and functional study of G protein-coupled receptors (GPCRs). Constitutively active mutant GPCRs leading to the activation of heterotrimeric GDP/GTP-binding protein signaling in the absence of ligand binding are of interest for the study of the activation mechanism in GPCRs. The present study focused on the opsin mutant E134Q/M257Y, which showed a moderate level of constitutive activity and the formation of two distinct rhodopsin chromophores with absorption maxima of 500 nm and 380 nm, depending on the presence of an inverse agonist, 11-cis-retinal, and an agonist, all-trans-retinal, respectively. Reconstitution of the mutant rhodopsin upon incubation with different ratios of 11-cis-retinal and the all-trans-retinal, as well as upon sequential binding of the two retinals, indicated its preferential binding to 11-cis-retinal. The thermal stability of the 11-cis-retinal-bound form of the E134Q/M257Y mutant was lower than that of the mutants containing a single replacement but higher than that of the all-trans-retinal-bound forms. The mutant also showed a lower stability in its opsin state as compared with that of the wild-type opsin but had little effects on the binding affinity to 11-cis-retinal. Information obtained in this study will be helpful for analyzing the structural changes associated with the activation of rhodopsin and GPCRs.