• Journal of Chest Surgery
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• 제17권1호
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• pp.125-128
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• 1984

The management of the exposed cardiac pacemaker or its lead is a new challenge to the plastic surgeon. This complication is not rare. Coburn et al. [1972] reported less than 5 percent, but Sowton et al. [1974] showed that over a period of 19 years, in a series of 372 patients, the pacing system had to be removed because of local wound breakdown or infection in 10 percent of the cases. The methods used to treat exposure may vary from removal and re-introduction at anterior site to the rotation of local flaps to cover the exposed pacemaker. Recently we have experienced 6 times of migration and recurrent skin ulcerations without pyogenic infection overlying the pacemaker in one patient. We developed a new technique, anchoring the pacemaker to the clavicle by a wire through the hole of clavicle and by creating a pocket under the pectoralis major muscle. Then we would like to emphasize this operating method could be choice of treatment to prevent the migration of pacemaker and the ulceration of skin when complication of implantation of pacemaker is occurred.

• Journal of Chest Surgery
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• 제51권5호
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• pp.363-366
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• 2018

One of the complications of permanent pacemaker implantation is unintended phrenic nerve stimulation. A 15-year-old boy with a permanent pacemaker presented with chest discomfort due to synchronous chest wall contraction with pacing beats. Even after reprogramming of the pacemaker, diaphragmatic stimulation persisted. Therefore, we performed thoracoscopic phrenic nerve insulation using a Gore-Tex patch to insulate the phrenic nerve from the wire. A minimally invasive approach using a thoracoscope is a feasible option for retractable phrenic nerve stimulation after pacemaker implantation.

• Journal of Chest Surgery
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• 제18권2호
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• pp.193-204
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• 1985

During the period from February to March, 1984, we employed a partial left heart bypass [left atrium to ascending aorta] in 2 patients who could not weaned from cardiopulmonary bypass with inotropic agents and cardiac pacing after coronary bypass surgery. These two patients showed significant improvement in ventricular function 18 to 47 hours after inserting the left heart bypass and were able to wean from the left heart bypass under using inotropic agents. Two patients died of multiple organ failures 11 days and 15 days postoperatively. These results indicate that early institution of left heart bypass in ventricular failure patients after open heart surgery can provide satisfactory long-term result.

• Journal of Chest Surgery
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• 제25권9호
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• pp.905-911
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• 1992

Automatic junctional tachycardia is one of common atrial arrhythmia after open heart surgery which is often refractory to antiarrhythmic agents. We have experienced refractory automatic junctional tachycardia in two patients. In the first, it occured after cryosurgery for AV nodal reentry tachycardia and simultaneous dissection of a posterior septal bypass tract. In the second, it complicated the postoperative course of a patient who received intracardiac repair for double outlet right ventricle, ventricular septal defect, and pulmonary stenosis. Conventional therapy with atrial pacing, verapamil, digoxin, and electrical cardioversion were ineffective. Therefore, amiodarone was administered intravenously and it controlled automatic junctional tachycardia. The need for accurate and rapid diagnosis of this condition along with results of treatment are discussed.

• 한국컴퓨터정보학회논문지
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• 제21권7호
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• pp.93-100
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• 2016

This paper shows what kind of influence the learning motivation factors have on the effectiveness of Flipped Learning Model through the case of operating a JAVA programming subject. The Flipped Learning Approach consisting of Before Class, Before or At Start of Class, and In Class provides the students with learning motivation as well as satisfies Keller's ARCS(Attention, Relevance, Confidence, Satisfaction) to keep them studying steadily. This research conducts the operation of Flipped Learning and gets Exploratory Factor Analysis and Reliability Analysis from the result of the course experience questionnaire at the end of the class. Given this survey result, Flipped Learning approach improves the learners' satisfaction in class and the effectiveness in the fields of understanding learning context more than does the previous lecture-based learning approach by pacing learning procedure and conducting self-directed learning.

• Journal of Chest Surgery
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• 제14권2호
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• pp.168-174
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• 1981

Since cardiac pacemaker was first totally implanted by Chardack, Gage and Greatbatch [1966], the electrical circuity of the cardiac pacemaker has been improved, modified, and refined. The problem of transvenous electrodes, however, is still remained; this may be due to electrode displacement, exit and/or entrance block, lead fracture and insulation defects. In permanent cardiac pacing, Irreversible loss of function of the transvenous electrode catheter eventually requires insertion of new lead. Authors now report one case that disclosed easy displacement of electrode tip in early phase of implantation and then two years and five months later, malfunctioning electrode could not be withdrawn from the cardiovascular system because it has become firmly enclosed by fibrous tissue along its course from the vein tract to the right ventricle. Under such circumstances, the electrode catheter tip was left in tricuspid annulus after being sutured at its entrance and burying the loop of lead in generator pocket. New other one electrode was then reimplantation through left external jugular vein.

• Journal of Chest Surgery
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• 제16권4호
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• pp.547-554
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• 1983

Implantation of Dual Chamber Pacemakers Which sense in the Atrium and the Ventricle, and sequentially or synchronously trigger impulses in the both chambers, has led us to the near realization of the ideal "Physiologic Pacing". We have experienced two cases of implantation of Dual chamber pacemaker in September and October, 1983. One patient was a 21-year-old male who had postoperative complete heart block since he was taken Total correction of TOF in May, 1983 . We implanted transvenously a dual chamber pacemaker, VDD type, through the left subclavian vein. In the other patient who came to the emergency room for partial obstruction of small bowels with severe abdominal pain, nausea and vomiting, in whom heart block was found, we implanted a DDD type pacemaker through the left subclavian puncture. The pacemakers have been functioning well postoperatively for more than two months, and the conditions of patient were uneventful.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2000년도 봄 학술발표논문집 Vol.27 No.1 (A)
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• pp.271-273
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• 2000

본 논문에서는 TCP 수신자가 지연 ACK 옵션(Delayed ACK Option)을 사용할 경우에 TCP 송신자에게 발생하는 성능 저하요인들을 분석하고 다음과 같은 해결책을 제시하였다. 먼저, 느린 시작 구간(Slow Start phase) 처음에 생기는 ACK 타임아웃은 큰 초기 윈도우(large initial window)또는 1-bit 마킹 기법을 통해 해결할 수 있다. 그리고, 느린 시작 구간과 혼잡 회피 구간(Congestion Avoidance phase)에서 혼잡 윈도우(cwnd)가 천천히 증가하는 문제는 적절히 바이트 카운팅 기법을 사용함으로써 해결할 수 있다. 마지막으로, 송신자가 버스트(burst)한 데이터를 네트웍에 발생시키는 문제는 트래픽을 평활(pacing)함으로써 해결할 수 있다. 또한 본 연구에서는 분석적 모델링을 통하여 TCP가 보내는 평균 전송률을 구하였으며 이 결과는 TCP에 친화한 전송률 기반 전송방법(TCP Friendly Rate Based Control)에 응용될 수 있을 것이다. 그리고 시뮬레이션을 통해서 제시한 방법의 성능이 향상됨을 확인하였다.

• 디지털산업정보학회논문지
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• 제4권1호
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• pp.105-117
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• 2008

T Abstract This study investigates the influence of differential factors on learner satisfaction by field-independent learning style in e-learning. Most of data were collected from students. Participants were classified based on a learning style typology (field-independent/dependent) and, then, analyzed was the influence of key factors on learner satisfaction using multiple regression analysis. This study suggests that e-Learning service providers need to differentiate learners based on learning style in order to improve learner satisfaction. Specially, Field independent learners are more likely to be satisfied by the teacher's provide degree of joyful, degree of contents, degree of learning control pacing, ability of problem solving and consistency.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2000년도 가을 학술발표회논문집
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• pp.273-280
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• 2000

Building structures which are in need of large open space make the damping effect of the structures decrease greatly. Assembly and office buildings with a lower natural frequency have a higher possibility of experiencing excessive vibration induced by human activities. These excessive vibration make the residents uncomfortable and the serviceability deterioration. The loads induced by human activities were classified into two types. First type is in place loads as like jumping, foot stamping and body bouncing. The other type is moving loads as like walking, running and dancing. A series of laboratories experiments had been conducted to study the dynamic loads induced by human activities, The earlier works were mainly concerned to parameters study of dynamic loads as like activity type, weight, sex, surface condition of structure and etc. In this paper, we have measured directly the walking loads by using the platform. And we have evaluated and analyzed load-time history of walking loads. One of the most important parameter is pacing rate (walking speed) in the walking loads. The difference between the maximum value and minimum value of walking loads depends on the walking speed.