• Journal of the Korean Society of Radiology
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• v.6 no.1
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• pp.5-10
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• 2012

There is a still unsettled issue about the comparison of long-term clinical effects between sirolimus-(SES) and paclitaxel-eluting stents (PES) for the patients with acute myocardial infarction (AMI). Therefore, we performed a retrospective analysis to evaluate the 4-year clinical outcome of SES as compared with PES after percutaneous coronary intervention (PCI) in patients with AMI. From January 2004 to August 2006, all consecutive patients with acute ST-segment elevation myocardial infarction (STEMI) underwent primary PCI and acute NSTEMI underwent PCI by implantation either SES or PES were enrolled. The occurrence of death, cardiac death, recurrent infarction, target vessel revascularization (TVR) and stent thrombosis were analyzed. The composite of major adverse cardiac events (MACE; death, recurrent infarction and TVR) were also analyzed. During the study period, total 668 AMI patients had visited. Of them, total 522 patients (299 with SES and 223 with PES) were enrolled. During 4-year clinical follow-up, there were similar occurrences of death ($18.3{\pm}3.0%$ vs. $14.6{\pm}2.2%$, p=0.26), cardiac death ($11.2{\pm}2.6%$ vs. $6.8{\pm}1.52%$, p=0.39), re-infarction ($6.4{\pm}1.8%$ vs. $3.3{\pm}1.1%$, p=0.31), and stent thrombosis ($5.4{\pm}1.7%$ vs. $3.2{\pm}1.1%$, p=0.53) between the two groups, consecutively. The occurrences of TVR ($10.0{\pm}3.0%$ vs. $4.0{\pm}1.2%$, p=0.008) and MACE ($29.4{\pm}3.5%$ vs. $19.4{\pm}2.5%$, p=0.003) were significantly higher in patients treated with PES than SES. In AMI patients treated with either SES or PES implantation, SES had a significantly lower risk of TVR and MACE during 4-year clinical follow-up. Rates of death, cardiac death or recurrent infarction, and stent thrombosis were similar.

• Journal of Yeungnam Medical Science
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• v.22 no.2
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• pp.211-220
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• 2005

Background: The purpose of this study was to determine the effectiveness of a percutaneously placed self-expanding metallic stent for the relief of biliary obstruction in patients with hilar cholangiocarcinoma. Materials and Methods: From November 2001 to December 2004, 48 patients with hilar cholangiocarcinoma were prospectively studied. After percutaneous placement of bilateral selfexpanding, uncovered metallic stents, follow-up evaluation was carried out until July 2005. Results: There were 4 cases of Bismuth type II, 21 cases of Bismuth type IIIa, 8 cases of Bismuth type IIIb and 15 cases of Bismuth type IV. Stent placement was technically successful in all patients. All patients had satisfactory biliary drainage, resulting in one week drainage rate of 72.8% and final drainage rate of 91.1%. There were 12 cases (21.3%) of abdominal pain requiring analgesics and 1 case (7.1%) of cholangitis; both were successfully managed with conservative treatments. Late complications occurred in four patient (8.3%), including two patients with cholangitis, one patient with liver abscess, and one patient with biloma; all were appropriately managed by percutaneous drainage. The average length and median durations of stent patency and median survival time were 303 days (range, 60~815) and 338 days (range, 60~1175), respectively. Conclusion: Placement of a percutaneous metallic stent is an effective and safe method for palliation of patients with hilar cholangiocarcinoma.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.7 no.2
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• pp.105-112
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• 2014

Purpose: Ultrasound-guided epidural caudal block for low back pain and radiating pain is often performed in the treatment of outpatients. However, this procedure has a failure rate of up to 25% even when it performed by an experienced physician. The authors investigate the effectiveness of Ultrasound-guided epidural caudal block in patients related to disc herniation or spinal stenosis. Materials and Methods: Ultrasound-guided caudal epidural block was performed in 55 outpatients with LBP and radiating pain. Patient was placed in the prone position and sonographic image of sacral hiatus was obtained using linear probe. A 22-gauge needle was advanced into the sacrococcygeal membrane under ultrasound guidance and then medication was injected into the caudal epidural space. There were 31 cases of disc herniation, and 24 cases of spinal stenosis. Patients were evaluated by Visual Analog Scale (VAS) pain score at pre-treatment, post-treatment, 2 weeks and 4 weeks by telephone interviews. Results: 53 of the 55 cases (96.4%) of needle insertion into the sacral canal under ultrasound guidance were successful. Gender was not significantly different between disc herniation group and spinal stenosis group. But there was a significant age difference between disc herniation group ($42.3{\pm}10.8$), and spinal stenosis group ($62.8{\pm}15.1$) [p<0.001]. The VAS score at pre-treatment, post-treatment, 2 weeks, 4 weeks in disc group were 6.84, 3.1, 1.8 & 1.77. The VAS score at pre-treatment, post-treatment, 2 weeks, 4 weeks in spinal stenosis group were 6.88, 3.58, 4.33 & 4.88. The VAS score in both groups was significantly improved after the procedure (p<0.001). Over time, the two groups were statistically significant differences in VAS score after adjusting for age (p<0.001). Conclusion: Ultrasound-guided caudal epidural block seems to provide a high success rate and a significantly better response in disc group than spinal stenosis group.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.3 s.180
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• pp.195-202
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• 2006

The degenerative lumbar spinal stenosis (DLSS) is a disease inducing low back pain, leg pain, convulsion. numbness, and neurogenic claudication from compression of nerve root. Intervertebra fixation was reported to increase the degeneration of neighbor lesion after treatment. Recently, a new surgical technique of inserting a fixator between interspinous processes has been introduced. The purpose of this study is to design the interspinous process fixator with flexibility to complement the trouble of using fixator in DLSS. This study evaluated the existing fixator through the mechanical test and modified it using the finite element analysis (FEA). The evaluation was based on the displacement, stiffness and von-Mises stress obtained from the mechanical test and calculated from the FEA in the biomechanical loading condition. Effects of variation in length and thickness were investigated to design an optimal fixator. Three prototypes were manufactured using FEA results. Mechanical tests under the biomechanical loading condition were performed to select the best one from these three. The selected fixator increased flexiblity by 32.9%.

• Journal of Chest Surgery
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• v.35 no.8
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• pp.590-593
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• 2002

Absent pulmonary valve syndrome with intact ventricular septum(APVS with IVS) is a rare congenital anomaly. The severe form of this syndrome, characterized by severe respiratory distress presented soon after birth, has been attributed to the compression of the airways caused by aneurysmal dilatation of pulmonary artery. Several operative treatments such as pulmonary valve insertion, or reductive angioplasty of pulmonary artery have been applied. We present a 3-day-old male who showed improvement after PDA ligation, reductive angioplasty of pulmonary artery, pulmonary valve reconstruction, and ASD closure.

• Journal of the Korean Vacuum Society
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• v.2 no.3
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• pp.346-354
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• 1993

The diamond particles and films were deposited on Si and qurtz substrate for $CH_4-H_2$ mixed gas by using RF plasma CVD. The temperature of substrate and the thinkness of films deposited on Si substrate were uniformly kept up by inserting metal plate between substrate and substrate holder. On increasing the reaction pressure in the same discharge power, the morphologies of films were changed from well-defind films to micro-crystal or ball-like. When diamond films were deposited on Si substrate from $CH_4-H_2$ mixed gas, we obtained well-defined diamond films at lower concentration than 0.5 vol% of $CH_4/H_2$. The deposited diamond films were indentified by SEM, XRD and Raman spectroscopy.

• Journal of Chest Surgery
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• v.10 no.1
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• pp.17-24
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• 1977

The present treatment of respiratory failure, using cuffed endotracheal and tracheostomy tube has produced, apparently with increasing frequency, three lesions which have serious ceminical manifestations such as tracheal stenosis, tracheomalasia, and localized tracheal erosion. Extensive resection and reconstruction of the trachea must be necessary because conservative treatment has generally failed in the fully developed stenotic lesion. of the mediastinal trachea following extensive resection is best accomplished by direct anastomosis of the patient`s own tracheobronchial tissue. Any replacement of the mediastinal trachea must be air tight and laterally rigid, and must heal dependably. A variety of materials has been used for substitution following circumferential excision of tracheal segments within the mediastinum. These attempts have often failed because of early leak or late stenosis. We have successfully performed circumferential resection and primary end-to-end anastomosis of the trachea for 4 cases of post-intubation tracheal stenosis located a few centimeter below the tracheostomy stoma in the period of 3 years between 1974 and 1976. The lesion in one patient was found in the upper trachea which was approached anteriorly through a cervicomediastinal incision with division of the upper sternum. Other three located in the lower half of the trachea were operated through a high transthoracic incision with appropriate hilar mobilization in addition to cervical flexion for the development of the cervical trachea into the mediastinum. There were no hospital death, but suture line granulations occurred in two patients were managed by bronchoscopic removal of granulations without difficulties.

• Proceedings of the Korean Society of Computer Information Conference
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• 2013.07a
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• pp.11-13
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• 2013

무선 센서 네트워크는 개방된 환경에서 무작위로 배치되어 악의적인 공격자들에게 쉽게 노출된다. 센서 노드는 한정된 에너지 자원과 손쉽게 훼손된다는 단점을 통해 허위 보고서와 투표 삽입 공격이 발생한다. Li와 Wu는 두 공격을 대응하기 위해 확률적 투표기반 여과기법을 제안하였다. 확률적 투표기반 여과기법은 고정적인 검증 경로를 결정하기 때문에 특정 노드의 에너지 자원고갈 위험이 있다. 본 논문에서는 센서 네트워크에서 보고서 여과 확률 향상을 위하여 퍼지 시스템을 기반으로 다음 노드 선택을 약 6% 효율적인 경로 선택 방법을 제안한다. 제안 기법은 전달 경로 상의 노드 중 상태정보가 높은 노드를 검증 노드로 선택하고, 선택된 검증 노드는 허용 범위 경계 값을 기준으로 공격 유형을 판별하고 여과한다. 실험결과를 통해 제안기법은 기존기법과 비교하였을 때 에너지 효율이 향상되었다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.9
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• pp.931-935
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• 2003

A multilayer two-stage LC bandpass filter using low-temperature cofired-ceramic(LTCC) is proposed in this paper. The proposed bandpass filter is composed of two ceramic substrates with different dielectric constant instead of single ceramic material from top to bottom layer. Inductive elements are designed in a low permitivity ceramic layer to reduce parasitic effects and loss, while capacitive elements are designed in a high permitivity ceramic layer for size reduction. The proposed filter has 950 MHz center &equency, 118 MHz tractional bandwidth, and 3.5 dB insertion loss. And, the total size of this filter is 2.5${\times}$2.5${\times}$l.4mm$^3$. The performance of filter is analyzed by changing coupling capacitance between each resonator.

• 한국HCI학회:학술대회논문집
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• 2007.02b
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• pp.1-6
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• 2007

최근 다양한 기기와 환경에서 문자 입력에 대한 요구가 높아지고 있다. 이에 따라 효율적인 문자 입력 인터페이스 설계를 위해 문자 입력 인터페이스의 평가가 필요한 실정이다. 기존 연구를 살펴보면 문자 입력 시간을 시각 탐색 시간과 손가락 이동 시간으로 나누고 정보처리 이론인 Hick-Hyman Law와 Fitts’ Law를 통해 예측, 평가 하였다. 하지만 위 두 과정은 연속적(serial)인 과정으로 눈과 손의 coordination(협응)에 대해 관과 하는 한계가 있다. 또한, 기존 문자 입력 시간 예측 모델은 전문가라는 특정 숙련도를 가정하고 만들어졌기 때문에 실제 문자 입력 시간에 비해 과대 측정되어 왔다. 이에 본 연구는 문자 입력 시간 예측 모델에 눈-손 coordination 매개변수를 삽입하고자 눈-손 coordination의 시간을 측정하고 행태를 분석하였다. 또한, 비숙련자와 숙련자의 구분을 통해 시각 탐색 시간과 손 움직임 시간 그리고 눈-손 coordination의 시간 과 행태가 어떻게 변화하는 지 분석하였다. 그 결과 눈-손 coordination 시간은 문자 입력 시간과 밀접한 관계가 있었다, 그리고, 눈-손 coordination 시간은 숙련도에 상관없이 문자 입력 시간의 22%를 차지하였다. 또한, 숙련자와 비숙련자의 문자 입력 시간과 비교해 손과 coordination 시간 비율은 차이가 없었다. 하지만, 눈의 움직임 시간 비율은 큰 차이를 나타내었다. 이 결과는 눈-손 coordination과 숙련도 차이를 기존 문자 입력 예측 모델에 매개변수로써 적용하기 위한 기초 자료가 될 것이다.