• Annual Conference of KIPS
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• 2013.11a
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• pp.921-924
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• 2013

최근 무선랜 기반 실내 측위시스템을 활용하는 위치정보 서비스가 주목을 받고 있다. 기존 측위 방식에서는 주로 삼각측량 기법에 의존하여 사용자 단말의 위치를 측정하고 있으나, 실내 벽 등의 장애물로 인하여 정확한 측위가 어려울 뿐만 아니라 측위 오차가 크다는 문제점이 있다. 본 논문에서는 무선랜 기반 실내 측위시스템에서 방(room) 등의 블록(block) 단위로 사용자의 위치를 측정하는 방법을 제시한다. 실험 결과, 제안 방식은 기존 방식에 비해 측위 오차를 50% 이상 감소시킬 수 있음을 확인하였다.

• Clinics in Shoulder and Elbow
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• v.1 no.1
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• pp.109-117
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• 1998

We evaluated the results of the surgery for impingement syndromes and partial thickness tears of the rotator cuff with an average follow-up period of 15 months. One group(group I) of 43 patients, 46 cases underwent arthroscopic subacromial decompression. The other comparable group(group Ⅱ) of 10 patients, II cases underwent open acromioplasty. The average age at operation was 48 years, old. Arthroscopic subacromial decompression achieved slightly better pain relief, the range of the acti ve forward flexion, function, strength and the overall score with improvement from the preoperative condition than open acromioplasty. The patient's satisfaction was better in group I as well. Using the UCLA Shoulder Rating Scale, 89% of group I and 82% of group n had good or excellent results. Preservation of the origin of the deltoid during an arthroscopic acromioplasty reduced the postoperative morbidity and made it possible to start rehabilitation sooner and to achieve the better and more predictable results.

• Clinics in Shoulder and Elbow
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• v.11 no.2
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• pp.165-171
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• 2008

Purpose: The purpose of this study was to introduce a new surgical technique and to evaluate the preliminary results after operative treatment with using TightRope$^{(R)}$ for treating acute acromioclavicular joint dislocation. Material and Methods: We studies 10 patients who were followed up for more than 6 months after operative treatment with using an TightRope$^{(R)}$. A longitudinal incision approximately 4cm in length was made from 1cm medial to the acromioclavicular joint to the coracoid process, and then coracocalvicular ligament augmentation using TightRope$^{(R)}$ was done after splitting the deltoid. For postoperative stability, two 1.6 mm Kirschner wires were inserted temporarily across the acromioclavicular joint in all cases. The radiologic results on the serial plain radiographs and the clinical results according to the UCLA score were analyzed. Results: Radiologically, 7 cases showed anatomical reduction, 2 cases showed a slightly loss of reduction and 1 case showed partial loss of reduction. Clinically, 6 cases were excellent, 3 cases were good and 1 case was fair. Conclusion: Coracoclavicular ligament augmentation using TightRope$^{(R)}$ for treating acute acromioclavicular joint dislocation is a minimally invasive, safe procedure that provides satisfactory radiologic and clinical preliminary results. Yet the long-term results have to be analyzed to determine the final results of this procedure.

• The Journal of the Korea Contents Association
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• v.9 no.11
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• pp.254-261
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• 2009

This study suggested that the table of CT-simulator and the laser alignment system using diagnostic CT scanner have an efficient method for improvement in alignment between the planned target center of traverse image with CT scanner. It was conducted on the daily QA when presented in the AAPM TG66 with correcting the laser alignment system using geometric trigonometric functions and investigated the effectiveness of correction methods as compared with those before and after correction. Before correction error was 3.82mm between the planned target center of image, the table longitudinal axis was twisted with 0.436o. The laser alignment system using geometric trigonometric functions in after correction was satisfied with tolerance limits of ${\pm}2mm$ when occurred about 0.7mm in errors between the planned target center. The table correction to satisfy the geometric accuracy is very inefficient over against the time and economic loss as well as technical limits in the case of application as only radiation therapy associated with CT-simulator with diagnostic CT scanner in use. But, the method which corrects the laser alignment system is economic and relatively simple with possibility of getting well geometric accuracy and we suppose that it is efficient method for applying in the clinic.

• Journal of the Korean Magnetics Society
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• v.26 no.3
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• pp.105-114
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• 2016

In this study, For assessment of triangular fibrocartilage complex (TFCC) injury, we acquired images by fat suppressed 3D fast spoiled gradient recalled T1 and fat suppressed Isotropic 3D fast spin echo T1 techniques. For quantitative evaluation, measured signal to noise ratio and contrast to noise ratio and verified statistical significance between two imaging techniques by Mann-Whitney U verification. And for qualitative evaluation, marked 4-grade scoring (0: non diagnostic, 1: poor, 2: adequate, 3: good) on shape of TFCC, artifacts by partial volumes, description of the lesions by two radiologist, verified coincidence between 2 observer using Kappa-value verification. We used 3.0 Tesla MR equipment and 8-channel RF coil for imaging acquisition. As quantitative evaluation results, signal to noise ratio and contrast to noise ratio value of Isotropic 3D fast spin echo T1 technique is higher in every image sections, also between two imaging techniques by Mann-Whitney U verification was statistically significant (p < 0.05). As qualitative results, observer 1, 2 marked a higher grade on Isotropic 3D FSE T1 technique, coincidence verification of evaluation results between two observers by Kappa-value verification was statistically significant (p < 0.05). As a result, during MRI examination on TFCC injury, fat suppressed Isotropic 3D fast spin echo T1 technique is considered offering more useful information about abnormal lesion of TFCC.

• Journal of Korean Medicine Rehabilitation
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• v.34 no.2
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• pp.85-100
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• 2024

Objectives This study aims to analyze clinical studies on subacromial-subdeltoid (SA-SD) bursitis and propose future directions for clinical research on SA-SD bursitis. Methods We searched eight databases to investigate research trends in Korean medicine treatments for SA-SD bursitis up to November 2023. A total of thirty-one studies were included in this analysis. Results Among the included studies, there were six case reports from Korea, fifteen case reports, and ten randomized controlled trials from abroad. Various interventions were uesd, including acupuncture, pharmacopuncture, manual therapy, electro-acupuncture, cupping, physiotherapy, acupotomy, warm-acupuncture, herbal medicine, and moxibustion. The evaluation tools used in these studies included the total effective rate, visual analogue scale, range of motion, and numeral rating scale. Conclusions This study provides an overview of the research trends in Korean medicine treatments for SA-SD bursitis. However, given the low quality and small sample sizes of the studies, the evidence supporting effect of Korean medicine treatments for SA-SD bursitis was insufficient. Further clinical trials and systematic reviews are required.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.5
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• pp.883-890
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• 2017

Among the augmented reality services, the most frequently used services are marker based augmented reality services. However, there is a problem that the augmented reality service can not be provided in an environment in which the marker image can not be recognized. In this paper, we propose a method to provide more stable service by estimating the user's posture even if the marker image can not be correctly recognized due to occlusion, obstacle or marker damage in the marker based augmented reality. In the proposed method, when a failure occurs in the provision of a marker based augmented reality, the attitude of the user is estimated using the 3-dimensional coordinates measured through communication between the three beacons and the user, and it allows the user to receive the augmented reality service continuously. We describe the scenario of augmented reality technique using proposed marker recognition and beacon communication, and present the results of experiments based on the degree of occlusion and damage.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1373-1377
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• 2008

강우-유출에 의해 성층화된 저수지로 유입하는 하천수는 저수지 표층에 비해 낮은 수온과 높은 부유물질(SS) 농도를 가지므로 저수지 표층수보다 상대적으로 높은 밀도를 유지한다. 하천으로부터 유입한 밀도류는 유속에 의한 관성력이 두 수체의 밀도차에 의한 음의 부력보다 큰 구간까지는 저수지 표층을 따라 진행하지만, 두 힘이 같아지는 지점에서 밀도류는 더 이상 진행하지 못하고 저수지 수면 아래로 침강하며 이 과정에서 수체간의 많은 혼합이 일어난다. 따라서 홍수시 유입한 탁수의 침강점에 대한 정확한 예측은 수질관리를 위한 현장조사, 그리고 탁수거동 해석 및 최적관리대책 마련에 중요한 요소이다. 본 연구의 목적은 홍수시 대청호로 유입하는 하천 밀도류의 침강위치를 홍수규모별로 경험식과 수치모델을 통해 산정함으로써 두 방법 간의 장 단점을 비교하고, 탁수 현장조사와 최적관리를 위한 기초정보를 제공하는데 있다. 유입수의 모의조건은 그 동안 대청호에서 발생한 홍수 크기를 기준으로 9개의 등급으로 나누었으며, 저수지 성층조건은 여름철 탁수가 유입되기 전의 발달된 성층구조를 적용하였다. 유입수와 저수지 성층구조의 특성치는 밀도 Froude 수($Fr_i$)로 나타냈으며, $Fr_i$ 조건별로 침강점 위치를 저수지 단면을 삼각형태로 가정한 Hebbert et al.(1979) 경험식과 2차원 수치모델로 산정하여 그 결과를 비교하였다. 대청호로 유입한 탁수는 홍수규모에 따라 대정리 수역에서 회남수역 사이 구간에서 침강하였으며, $Fr_i$ 값이 클수록 침강점 수심이 깊어지는 경향을 보였다. 경험식으로 산정한 침강점 수심은 정상상태 조건을 가정하므로 홍수에 의한 수위변화를 고려하지 못하며, 실제의 불규칙한 하상표고를 일정한 하상경사로 가정하기 때문에 2차원 모델의 결과보다 과대산정하는 경향을 보였다. 따라서 홍수가 연속해서 발생하며 수위변화가 심한 국내 저수지 여건에서 하천 유입 밀도류의 거동을 보다 정확히 예측하기 위해서는 2차원 또는 3차원 수치모델을 적용하는 것이 타당할 것으로 판단된다.

• Journal of IKEEE
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• v.2 no.1 s.2
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• pp.53-60
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• 1998

We develope a high repetition rate, short distance, optical range finder for surface roughness measurements of large structures, such as a highway road, etc. For range measurement based on a triangulation principle, we use a light emitting diode and an one dimensional Position sensitive photodetector for a light source and an angle detector of the reflected light at the object, respectively. The range finder has automatic power control and electrical background noise rejection capabilities which enable it to overcome variations of an object reflectance and to eliminate time-varying, as well as constant, background light noises. Our experimental results show less than ${\pm}1.5mm$ of measurement errors regardless of an object reflectance, for $22{\sim}38cm$ object ranges which are determined by considering the installation of the range finder and the depth of surface roughness.

• Archives of Reconstructive Microsurgery
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• v.1 no.1
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• pp.51-55
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• 1992

Problems of composite tissue transfer commonly arise when a single indispensable recipient vessel receives the graft vssel, and the graft vessel must be sutured in end-to-side fashion so as not todisturb the vascularity of the recipient vessel. The triangular flap in the recipient vessel wall gives an intact endothelial surface when the flow of blood stream is presented and may reduce the chance of anastomosis. We selected mature Wistar rats weighing over 450 grams to compare the conventional longitudinal slit from the triangular flap in the recipient carotid artery over bloood pressure and blood flow when the donor carotid artery was anastomosed in end-to-side fashion. In 30 minutes after anastomosis, maximum blood pressure measured in the donor carotid arterial side when the recipient arterial wall was fasioned with the longitudinal slit was recorded 114 mmHg and with the triangular flap 100mmHg. Minimum blood pressure with the longitudinal slit was 98mmHg and with the triangular flap 88mmHg. The amount of blood collected for 30 seconds in the conventional longitudinal slit was 1.18mg and in the triangular flap 0.78mg. Histology study in 30 minutes, the conventional longitudinal slit demonstrated the more hemorrhagic features around the suture material compared to that of the triangular. flap and, in the 7th day, the conventional longitudinal slit demonstrated the more prominent granulomatous reactions and vascular proliferations around the suture material compared to that of the triangular flap.