• Therapeutic Science for Rehabilitation
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• v.2 no.1
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• pp.24-35
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• 2013

The Purpose of this study was to determine the clinical effectiveness of mirror therapy for stroke. Moreover, this paper was designed to summarize clarified information of neurological plasticity by mirror therapy to finally define the neurological mechanism. Mirror therapy improves the stroke patients' hand and arm motor function. It also has a positive influence on recovering performance of activities of daily living and relieving pain. However, it is not evident that mirror therapy restores visual neglect. There are various ways of recovering stroke. Fundamentally, all the theories are on a bases of restoration of premotor area. Premotor area which is associated with motor control increases the activation of primary motor area and finally improves patients' motor function. If primary motor area is completely damaged, premotor area and supplementary motor substitute for primary motor area. In summary of literature survey, there are not enough evidence to verify the effectiveness and neurological mechanism of mirror therapy. In future, more researches should be conducted to verify the neurological recovery through mirror therapy. Then, mirror therapy will be acknowledged as a clinically effective treatment.

• Journal of KIISE:Information Networking
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• v.32 no.5
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• pp.574-582
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• 2005

Localization in wireless sensor networks is essential to important network functions such as event detection, geographic routing, and information tracking. Localization is to determine the locations of nodes when node connectivities are given. In this paper, centroid approach known as a distributed algorithm is extended to a centralized algorithm. The centralized algorithm has the advantage of simplicity. but does not have the disadvantage that each unknown node should be in transmission ranges of three fixed nodes at least. The algorithm shows that localization can be formulated to a linear system of equations. We mathematically show that the linear system have a unique solution. The unique solution indicates the locations of unknown nodes are capable of being uniquely determined.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.993-997
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• 2004

파장다중분할 방식의 광통신소자는 단일파장 뿐만 아니라 이웃하는 여러 파장대에서도 동작 할 수 있는 유연성을 갖는 소자가 요구된다. 이를 해결하는 하나의 방법이 파장제어(다중채널)광자결정(Photonic crystal)소자이다. 본 연구에서는 결함층으로 광자결정체 배열구조를 가지는 다중주기 일차원광자결정을 이용하므로 투과광 파장제어가 가능한 가변형 다중채널 투과필터를 얻을 수 있는 이론적 모델과 그에 따라 제작된 $Si/SI_)2$의 광자결정체를 제작하고 그 특성을 고찰하였다. 반사밴드 갭내에 생성된 다중투과-dip의 파장 위치는 이론값과 정착하게 일치하였다. 특히, 결함층 수(N)에 따라 광자 에너지갭내에 2N개의 투과-dip 모드를 생성할 수 있으며, 이들은 주파수범위에 대해 대칭 분포됨을 알 수 있다. 여기에 제안하는 다중채널 투과필터는 외부 전원 없이 입사각도를 미세 조절하므로 파장을 tuning할 수 있다.

• Journal of the Korean Geotechnical Society
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• v.20 no.6
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• pp.5-10
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• 2004

The earth pressure coefficient at rest for clayey soils in the one-dimensional state, $K_0$ obtained from the triaxial test is not correct in principle because the seepage flow is radial and the displacement of soil elements is three-dimensional. Measurements of the earth pressure and the pore water pressure during one-dimension consolidation in the consolidometer ring are presented. The earth pressure and pore water pressure are measured directly by a circular part of the consolidometer ring of a floating type at its mid height. A plastic clay showed $K_0$=0.5 irrespective of pressure in the consolidometer ring.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.2
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• pp.291-301
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• 1999

A method for the synthesis of one-dimensional nonlinear distribution function is presented for the desired inverse scattering pattern. This method is based on the inverse transform of the solution of the Riccati equation derived from one-dimensional inverse scattering problem. Since the solution is analogous to the array factor or normalized space factor in collinear array antenna, the synthesis method for field pattern is applied for the construction of the involved line-source nonlinear distribution function. The suggested method is carried out under the optimization process, and is numerically verified by synthesizing the dispersive transmission line profile within the specified frequency band and control of scattered field on resistive strip.

• Journal of the Korean Society of Radiology
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• v.84 no.1
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• pp.197-211
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• 2023

Purpose To evaluate the circuit patency after nitinol bare-metal stent (BMS) placement according to the type of access and location of the stent in dysfunctional hemodialysis access. Materials and Methods Between January 2017 and December 2019, 159 patients (mean age, 64.1 ± 13.2 years) underwent nitinol BMS placement for dysfunctional access. The location of stents was as follows: 18 brachiocephalic vein, 51 cephalic arch, 40 upper arm vein, 10 juxta-anastomotic vein, 7 arteriovenous (AV) anastomosis, and 33 graft-vein (GV) anastomosis. Circuit patency was evaluated by the Kaplan-Meier method, and cox regression model. Results A total of 159 stents were successfully deployed in 103 AV fistula (AVF) and 56 AV graft (AVG). AVG showed lower primary and secondary patency at 12-months compared with AVF (primary patency; 25.0% vs. 44.7%; p = 0.005, secondary patency; 76.8% vs. 92.2%; p = 0.014). Cox regression model demonstrated poorer primary patency at 12 months after stenting in the cephalic arch and GV anastomosis compared with the other sites. Conclusion AVF showed better primary and secondary circuit patency at 12 months following the placement of BMS compared with AVG. Stents in the cephalic arch and GV anastomosis were associated with poorer primary patency at 12 months compared to those in other locations.

• Investigative Magnetic Resonance Imaging
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• v.1 no.1
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• pp.103-107
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• 1997

Purpose: To investigate the localization and functional lateralization of the supplementary motor area (SMA) in motor activation tests in comparison to that of the primary motor area. Materials and Methods: Seven healthy volunteers obtained echoplanar imaging blood oxygen level dependent technique. This study was carried on 1.5T Siemens Magnetom Vision system with the standard head coil. Parameters of EPI were followed as; TR/TE : 1.0/66.0msec, flip angle: $90^{\circ}$, field of view: $22cm{\times}22cm,{\;}matrix:{\;}128{\times}128$, slice number/slice thickness/gap: 1O/4mm/0.8mm with fat suppression technique. Motor task as finger opposition in each hand consisted of 3 sets of alternative rest and activation periods. Postprocessing were done on Stimulate 5.0 by using cross-correlation statistics. To compare the functional lateralization of the SMA in the right and left hand tests, each examination was evaluated for the percent change of signal intensity and the number of activated voxels both in the SMA and in the pri¬mary motor area. Hemispheric asymmetry was defined as difference of summation of the activted voxels between each hemisphere. Results: Percent change of signal intensity in the SMA (2.49 -3.06%) is lower than that of primary motor area(4.4 -7.23%). Percent change of signal intensity including activated voxels were observed almost equally in the right and left SMA. As for summation of activated voxels, primary motor area had significant difference between each hemisphere but not did the SMA. Conclusion: Preferred contralateral dominant hemisphere and hemispheric asymmetry were detected in the primary motor area but not in the SMA.

• Journal of Chest Surgery
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• v.42 no.6
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• pp.738-743
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• 2009

Background: There is no standardized tool and parameter that can accurately assess the sympathetic function before and after performing sympathectomy in patients with primary palmar hyperhidrosis. We examined the effective-ness of the sympathetic skin response (SSR) study for documenting the change of sympathetic denervation before and after performing selective thoracic sympathicotomy. Material and Method: We prospectively investigated the SSR from 12 healthy subjects who were diagnosed with primary hyperhidrosis. Each SSR was recorded on the right palm or sole with electrical stimuli applied to the skin at the left wrist and foot and vice versa for the controlateral side. This test was performed before, 2 weeks and 1 year after selective thoracic sympathicotomy. The data was corrected for the onset latency and the amplitude of the SSR (n=24). Result: The mean age of the 12 patients was $24.6{\pm}0.4$ years (range: 19~36) and the gender ratio was 1 : 0.7. The mean values of the preoperative, postoperative 2 weeks and postoperative 1 year onset latency and amplitude of the palmar side (n=24) were $1.46{\pm}0.24$ msec and $6,043{\pm}2,339{\mu}V$, $1.63{\pm}0.42$ msec and $823{\pm}638{\mu}V$, and $1.44{\pm}0.39$ msec and $2,412{\pm}1,546{\mu}V$, respectively. The mean values of the plantar side (n=38) were $1.83{\pm}0.42$ msec and $2,816{\pm}1,694{\mu}V$, $2.16{\pm}0.39$ msec and $1,445{\pm}1,281{\mu}V$ and $1.95{\pm}0.25$ msec and $1,622{\pm}865{\mu}V$, respectively. Among the documented parameters, only the palmar amplitude (p=0.002) showed statistical significance in recording the change of the sympathetic system within the same individual for the pre and postoperative period. Conclusion: The SSR amplitude ratio may be a useful parameter for documenting the efficacy of sympathetic denervation after selective sympathicotomy.

• Proceedings of the KAIS Fall Conference
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• 2011.12a
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• pp.185-188
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• 2011

병원 전 단계에서는 일반인 단계, 일차 반응자 단계, 기초응급의료 제공 단계 그리고 전문응급의료 제공단계로 구분되는데 각 단계의 적절한 병원 전 응급의료 서비스의 제공은 환자의 예후에 긍정적인 영향을 미치는 것으로 알려져 있다. 그러나 국내의 일반인 단계 및 일차 반응자 단계의 응급의료 제공은 매우 낮은수준이며, 응급의료체계는 전문 응급의료가 뒤따르지 않는 기초 응급의료만을 제공할 뿐인데도 그 적절성에 대하여 많은 문제점이 지적되어 오고 있다. 우리나라의 병원 전 응급의료체계는 비교적 짧은 기간 동안에 소방서를 축으로 운영되고 있다. 병원 전 단계에서 응급처치의 적절성을 높이기 위해서는 119구급대에 의한 응급처치에 대하여 체계적으로 조사를 수행함으로써 기초 응급의료에 대한 지속적인 질 관리를 해 나가는 것이 매우 중요하다. 이러한 질 관리의 평가를 위해서는 적절한 평가도구가 필요한데 객관성이 높으면서도 비용-효과적인 도구와 지표는 아직 확립되지 못하고 있는 것으로 보인다. 그동안 119 구급대에 의한 응급처치의 적절성에 대하여 몇 차례 보고가 있었지만, 단일 기관 또는 단일 질병을 대상으로 수행된 연구였거나 일개 응급의료기관으로 이송된 환자들만을 대상으로 했던 비교적 소규모의 보고들이었으며, 한 도시를 전체를 대상으로 한 광범위한 조사가 이루어진 적은 아직 없었다. 이에 이 연구에서는 대구 경북 지역의 119구급대원을 대상으로 병원 전 응급처치의 실태와 및 교육현황을 조사하여 응급처치의 질적 향상을 위한 프로그램 개발에 필요한 기초 자료를 제공하고자 한다.

• Journal of Chest Surgery
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• v.31 no.10
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• pp.999-1003
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• 1998

Background: Thoracoscopic sympathetic block in palmar hyperhidrosis has merits in its immediate responsiveness and recovery. In palmar hyperhidrosis, the level of sympathetic chain to be blocked has been somewhat obscure. Materials and methods: To compare the results of T2 with T2,3 sympathetic block, we retrospectively studied 192 patients (T2 group: 84, T23 group: 108) operated on at SNUH with palmar hyperhidrosis between April 1994 and July 1997. We reviewed medical records and recently interviewed the patients by telephone call. Sex and age distribution between two groups showed no significant differences. We performed sympathectomy at the early phase of the syudy until April 1997, and after then, we adopted sympathicotomy rather than sympathectomy. Results: All patients showed symptomatic improvement after the operation. Mean operation times of T2, T23 groups were 61.3$\pm$22.5min, 82.7$\pm$24.8min, respectively(p<0.01). Early postoperative complications, such as Horner's syndrome or chest tube insertion, were not different in two groups. There were no statistical differences of late complications such as compensatory truncal hyperhidrosis, gustatory sweating, and phantom sweating. No patient experienced recurrence of palmar hyperhidrosis during the study period. The only difference was the extent of compensatory truncal hyperhidrosis. The compensatory sweating occurred from axilla to suprapatella in T2 group whereas its extent was from nipple to suprapatella in T23 group. Conclusions: We concluded that T2 thoracic sympathetic block is mandatory for the treatment of primary palmar hyperhidrosis.