• Physical Therapy Korea
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• v.18 no.4
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• pp.43-50
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• 2011

The purpose of this study was to investigate the changes in the flexicurve kyphosis index (KI), the flexicurve lordosis index (LI) and the distance from the inferior angle of the scapula to the nearest vertebral spinous process (DS), as a dependent variable of scapular protraction, after applying of adolescents with thoracic hyperkyphosis using three different garments. A repeated measures design was used. Ten adolescents ($15.8{\pm}1.0$ years) with thoracic hyperkyphosis ($40.1{\pm}3.7$ Cobb angle) were recruited from a university hospital. A flexicurve ruler was used to measure KI and LI and a scoliometer was used to measure DS under three different conditions: wearing-a hospital garment (HG), wearing-a sham garment (SG), and wearing-an experimental garment (EG). KI under EG condition was significantly decreased compared with that wearing the HG. However, there was no significant difference between wearing the SG and HG. LI when wearing the EG was significantly increased compared with that when wearing HG. However, there was no significant difference under SG and HG conditions. DS when wearing the EG was significantly decreased compared with wearing HG. However, there was no significant difference between the SG and HG. The results of this study show that the EG was effective in decreasing KI, but not effective in decreasing LI. Hence, the effect of the EG for correcting sagittal spine angle in adolescents with thoracic hyperkyphosis is still debatable. However, since we showed that DS decreases in the EG, this method could be applied in correcting the scapular protraction.

• Journal of Korean Foot and Ankle Society
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• v.6 no.2
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• pp.156-160
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• 2002

Purpose: To analyze the clinical outcome of triple arthrodesis for the posttraumatic arthritis after calcaneal fractures. Materials and Methods: We retrospectively reviewed 22 posttraumatic arthritis patients who underwent a triple arthrodesis from March 1991 to May 1998. The mean duration of follow up was 74 months(range, 36-123 months). The pain, function and alignment were evaluated by the modified ankle-hindfoot scale of the American Orthopaedic Foot and Ankle Society(AOFAS) clinically and the union rate, the duration of union and the degenerative change of adjacent joints radiographically were evaluated. Results: The mean duration from injury to arthrodesis was 33 months (range, 12-132 months). The AOFAS score improved from 36.4 points(range, 14-64) preoperatively to 67.6(range, 25-90) postoperatively. The union rate was 90.1% radiographically, the mean duration of union was 14.3 weeks(range, 12-21 weeks) and the degenerative change in the adjacent joint was showed in 12 patients(54.5%). There were 2 cases of talonavicular nonunion, one superficial wound infection and one partial skin necrosis. Conclusion: Triple arthrodesis for posttraumatic arthritis after calcaneal fractures is a useful method for relief of pain and correction of posttraumatic hindfoot deformity, as an evidenced by the satisfactory clinical outcome. Although a high prevalence of subsequent arthritis of the ankle and midtarsal joint was noted radiographically, we found that it was not clinically relevant.

• International Journal of Fluid Machinery and Systems
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• v.9 no.1
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• pp.66-74
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• 2016

Concerning the numerical simulation of high-speed water jet with intensive cavitation this paper presents a practical compressible mixture flow method by coupling a simplified estimation of bubble cavitation and a compressible mixture flow computation. The mean flow of two-phase mixture is calculated by URANS for compressible fluid. The intensity of cavitation in a local field is evaluated by the volume fraction of gas phase varying with the mean flow, and the effect of cavitation on the flow turbulence is considered by applying a density correction to the evaluation of eddy viscosity. High-speed submerged water jets issuing from a sheathed sharp-edge orifice nozzle are treated when the cavitation number, ${\sigma}=0.1$, and the computation result is compared with experimental data The result reveals that cavitation occurs initially at the entrance of orifice and bubble cloud develops gradually while flowing downstream along the shear layer. Developed bubble cloud breaks up and then sheds downstream periodically near the sheath exit. The pattern of cavitation cloud shedding evaluated by simulation agrees experimental one, and the possibility to capture the unsteadily shedding of cavitation clouds is demonstrated. The decay of core velocity in cavitating jet is delayed greatly compared to that in no-activation jet, and the effect of the nozzle sheath is demonstrated.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.2A
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• pp.20-25
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• 2005

A high performance Viterbi decoder is designed using modified register exchange scheme and block decoding method. The elimination of the trace-back operation reduces the operation cycles to determine the merging state and the amount of memory. The Viterbi decoder has low latency, efficient memory organization, and low hardware complexity compared with other Viterbi decoding methods in block decoding architectures. The elimination of trace-back also reduces the power consumption for finding the merging state and the access to the memory. The proposed decoder can be designed with emphasis on either efficient memory or low latency. Also, it has a scalable structure so that the complexity of the hardware and the throughput are adjusted by changing a few design parameters before synthesis.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.387-390
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• 2005

A This paper presents a novel three-phase current-fed Pulse Width Modulation converter with switched- capacitor type resonant DC link commutation circuit operating PWM pattern strategy under a design consideration of low-pass filter, which can operate on the basis of the principle of zero current soft-switching commutation. In the first place, the steady-state operating principle of this converter with a new resonant DC link snubber circuit is described in connection with the equivalent operation circuit, together with the practical design procedure of the switched-capacitor type resonant DC link circuit is discussed from a theoretical viewpoint on the basis of a design example for high-power applications. The actively delayed time correction method to compensate distorted currents due to a relatively long resonant commutation time is newly implemented in the open loop control scheme so as to acquire the new optimum PWM pattern. Finally, the experiment or set-up in laboratory system or this converter is concretely demonstrated herein to confirm a zero current soft-switching commutation of this converter. The comparative evaluations between current-fed hard switching PWM and soft-switching PWM converters are carried out from a viewpoint of their PWM converter characteristics.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.8
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• pp.1854-1863
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• 2003

In the recent digital communication systems, the performance of Turbo Code using the mr correction coding depends on the interleaver influencing the free distance determination and the recursive decoding algorithms that is executed in the huh decoder. However, performance depends on the interleaver depth that needs many delays over the reception process. Moreover, turbo code has been blown as the robust coding methods with the confidence over the fading channel. International Telecommunication Union(ITU) has recently adopted it as the standardization of the channel coding over the third generation mobile communications(IMT­2000). Therefore, in this paper, we preposed the interleaver that has the better performance than existing block interleaver, and modified turbo decoder that has the parallel concatenated structure using MAP algorithm. In the real­time voice and video service over third generation mobile communications, the performance of the proposed two methods was analyzed and compared with the existing methods by computer simulation in terms of reduced decoding delay using the variable decoding method over AWGN and fading channels for CDMA environments.

• Journal of KIISE:Software and Applications
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• v.31 no.7
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• pp.939-948
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• 2004

In this paper. we Propose a robust and fast image registration technique for motion correction in brain CT-CT angiography obtained from same patient to be taken at different time. First, the feature points of two images are respectively extracted by 3D edge detection technique, and they are converted to locally weighted 3D distance map in reference image. Second, we search the optimal location whore the cross-correlation of two edges is maximized while floating image is transformed rigidly to reference image. This optimal location is determined when the maximum value of cross-correlation does't change any more and iterates over constant number. Finally, two images are registered at optimal location by transforming floating image. In the experiment, we evaluate an accuracy and robustness using artificial image and give a visual inspection using clinical brain CT-CT angiography dataset. Our proposed method shows that two images can be registered at optimal location without converging at local maximum location robustly and rapidly by using locally weighted 3D distance map, even though we use a few number of feature points in those images.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.8
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• pp.1677-1690
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• 1997

Block-transform coding is one of the most popular approaches for image compression. For example, DCT is widely used in the internaltional standards standards such as MPEG-1, MPEG-2, JPEG, and H.261. In the block-based transform coding, blocking artifacts may appear along block boundaries, and they can cause severe image degradation eqpecially when the transform coefficients are coarsely quantized. In this paper, we propose a new method for blocking artifacts reduction in transform-coded images. For blocking artifacts reduction, we add a correction term, on a block basis, composed of a linear combination of 28 basis images that are orthonormal on block boundaries. We select 28 DCT kernel functions of which boundary values are linearly independent, and Gram-Schmidt process is applied to the boundary values in order to obtain 28 boundary-orthonormal basis images. A threshold of bolock discontinuity is introduced for improvement of visual quality by reducing image blurring. We also investigate the number of basis images needed for efficient blocking artifacts reduction when the compression ratio changes.

• Archives of design research
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• v.12 no.4
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• pp.211-220
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• 1999

This study purposed more effective drawing process in practical lecture with students. Researched materials were constitution to a semester of presentation technique curriculum major in industrial design for freshman course. Students exert to entrance examination of university to get a good point in practical test. There did not have creative action in minds. But, design required concept of good idea sketch and creative technique. At study process should make correction a reform to sketch skill by repeat practicing with misunderstand drawing or imitative idea sketch. According to the practical test result & response revised lecture schedule. And then, I had survey to questionnaire paper for feedback by trial result. Besides, I was study to effect use the drawing materials for example, colored pencil, marker pastel. I think important to first use to way understanding materials and basic training. Design education be driven to new creative sketch skill. Design is the creative process to which brings ideas to reality.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.6
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• pp.485-491
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• 2012

The wall interference effects around the wind-turbine airfoil are experimentally investigated at low Reynolds numbers in a closed test-section wind tunnel. The test is performed at free-stream velocities from 10 to 31 m/s, which correspond to Reynolds numbers ranging from $1.5{\times}10^5$ to $4.6{\times}10^5$ based on chord of the airfoil. The blockage-area ratios, which is the ratio of the chord to the test-section width, are 27.8%, 38.5%, 41.7%, 45.5%, and 55.6%. The test results for the airfoil show that the transition point on the airfoil surface tends to move backward due to wall interference. The wall pressures for an adequate interference correction by a measured-boundary-condition method are desirable more than three times region of the chord before and after around the reference center.