• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.2
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• pp.352-360
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• 1997

An inverse dynamic procedure for spatial multibody systems containing flexible bodies is developed in the relative joint coordinate space. Constraint acceleration equations are derived in terms of relative coordinates using the velocity transformation technique. An inverse velocity transformation operator, which transforms the Cartesian velocities to the relative velocities, is derived systematically corresponding to the types of kinematic joints connecting the bodies and the system reference matrix. Using the resulting matrix, the joint reaction forces and moments are analyzed in the Cartesian coordinate space. The formulation is illustrated by means of two numerical examples.

• Journal of Digital Contents Society
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• v.6 no.4
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• pp.243-248
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• 2005

In this paper, We proposed joint-modulation CDMA system for efficient streaming transmission. and, We analyzed joint-modulation CDMA system using nakagami fading model and impulsive interference model for transmission channel environment. Also, it can being compensate the performance degradation by using MRC diversity scheme and BCH coding scheme.

• Journal of Biomedical Engineering Research
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• v.14 no.2
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• pp.113-123
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• 1993

The aim of this study is to design a electrogoniometer for the measurement of three dimensional human elbow joint rotations. Using this device and visual monitor, we measured the angle of elbow joint rotations during the goal-directed movements. And we extracted myoelectric signals(MES) to verify the inter-relationship of elbow joint activities and constructed a system for the analysis of the spectrum for MES. The data obtained from this system will be used for the controller signal of prosthetic arm.

• Korean Institute of Interior Design Journal
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• v.18 no.3
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• pp.39-46
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• 2009

The purpose of this study is to analyze the meaning of 'dis-joint' in the works of Louis I. Kahn. Kahn tried to realize his main architectural thoughts of 'what it wants to be' and 'how it was done' through his whole life. The concept of 'dis-joint' had been developed to visualize his architectural thoughts. Kahn used' dis-joint' to show and emphasize the structural system for the raison d'etre of building. Kahn's 'dis-joint' can be categorized as 'spacing', 'butt', 'slit' and 'protrusion'. Kahn used this kind of unusual way of joint beyond simple exposure to stress the existence of element, part and building itself. Through variable combination usage of 'dis-joint', Kahn can realize his architectural thoughts into building in a concrete way. The efficiency and function of joint is not the main issue in his works. 'Dis-joint' was the concrete tool to show the tectonic of architecture and construction process to enhance its presence. Therefore 'dis-joint' of Kahn's architecture is not a joint only to combine building parts but a concrete mean to realize his thoughts in a corporeal way. These facts insinuate that Kahn's architectural philosophy is based on the thoughts of tectonic and its realization.

• Tunnel and Underground Space
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• v.12 no.4
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• pp.268-276
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• 2002

In this study, a 3D coordinate measurement system equipped with a laser displacement meter for digitizing rock joint surface was established and the digitized data were used to calculate several roughness parameters. The parameters used in this study were micro avenge inclination $angle(i_{ave})$, average slope of joint $asperity(SL_{ ave})$, root mean square of $i-angle(i_{rms})$, standard deviation of height(SDH), standard deviation of $i-angle(SD_i)$, roughness profile $index(R_P)$, and fractal dimension(D). The relationships between the roughness parameters based on the digitzation of the surface profile were analyzed. Since the measured value varied according to the degree of reflection and the variation of colors at the measuring point, rock joint surface was painted in white to minimize the influence of the surface conditions. The comparison of the measured values and roughness parameters before and after painting revealed the better consequence from measurement on the painted surfaces. Also, effect of measuring interval was studied. As measured interval was increased, roughness parameters were exponentially decreased. The incremental sequence of degree of decrease was $SDH\; i_{ave},\; i_{rms},\; SD_i,\;and\; R_ p-1$. As a result of comparison of parameters from pin-type measurement system and laser type measurement system, all value of parameters were higher when laser-type measurement system was used, except SDH.

• Smart Structures and Systems
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• v.32 no.5
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• pp.309-318
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• 2023

The appropriate maintenance of highway roads is critical for the safe operation of road networks and conserves maintenance costs. Multiple methods have been developed to investigate the surface of roads for various types of cracks and potholes, among other damage. Like road surface damage, the condition of expansion joints in concrete pavement is important to avoid unexpected hazardous situations. Thus, in this study, a new system is proposed for autonomous expansion joint monitoring using a vision-based system. The system consists of the following three key parts: (1) a camera-mounted vehicle, (2) indication marks on the expansion joints, and (3) a deep learning-based automatic evaluation algorithm. With paired marks indicating the expansion joints in a concrete pavement, they can be automatically detected. An inspection vehicle is equipped with an action camera that acquires images of the expansion joints in the road. You Only Look Once (YOLO) automatically detects the expansion joints with indication marks, which has a performance accuracy of 95%. The width of the detected expansion joint is calculated using an image processing algorithm. Based on the calculated width, the expansion joint is classified into the following two types: normal and dangerous. The obtained results demonstrate that the proposed system is very efficient in terms of speed and accuracy.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.987-990
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• 1998

An optical adder for a modified signed-digit(MSD) number system using joint spatial encoding method is proposed. In order to minimize the numbers of symbolic substitution rules, nine input patterns were divided into five groups of the same addition results. For recognizing the input reference patterns, masks and reference patterns without any other spatial operations are used. This adder is implemented by smaller system in size than a conventional adder.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.9
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• pp.1332-1339
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• 1989

The problem of finding an admissible object trajectory for a cooperating two-robot system is investigated. The method is based on reformulating the problem as a nonlinear optimization problem with equality constraints in terms of the joint variables. The optimization problem is then solved numerically on a computer. The solution automatically gives the corresponding joint variable trajectories as well, thus eliminating the need for solving the inverse kinematic problem. The performance indices are chose in joint and cartesian spaces and computer simulations are performed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.932-935
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• 2005

Three dimensional laser welding technology for light car body is studied. A robot, a seam tracking system and 4kW CW Nd:YAG laser are used for three dimensional robot laser welding system. The Laser system is used 4kW Nd:YAG laser(HL4006D) of Trumpf and the Robot system is used IRB6400R of ABB. The Seam tracking system is SMRT-20LS of ServoRobot. The welding joint of steel plate are butt and lap joint. The 3-D welding for Non-linear Tailored blank is performed after the observation experiments of bead on plate. Finally, the welding process for non-linear tailored blank and front side member is developed.

• Korean Journal of Optics and Photonics
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• v.14 no.5
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• pp.491-497
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• 2003

In this paper, an optical encryption system using binary key code based on the joint transform correlator (JTC) is considered. The binary key code is synthesized by using a design technique of the pixel-oriented Computer Generated Holograms (CGHs). The independence and efficiency of the binary encryption key are investigated through computer simulation. To test the efficiency of the encryption system using binary key code, a holographic encryption system is constructed, and the experimental results prove that our holographic encryption system has high ability.