• Tribology and Lubricants
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• 제7권2호
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• pp.41-45
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• 1991

An experimental investigation for leakage performance of five anti-swirl self-injection seals was carried out to select an optimum configuration for minimum leakage. Test results show that the self-injection mechanism with a plain seal generally degrades the leakage performance of noncontacting seals; however, through a series of the test program, an optimum anti-swirl self injection seal was selected to obtain a comparable leakage performance with a damper seal. A 12 holes anti-swirl and anti-leakage self-injected. configuration with a labyrinth surface gives minimum leakage among the tested anti-swirl self-injection seals.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.725-728
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• 2000

Air hoist system has been using in the industry. In gradually, the system of function was developing, but system was not enough compensation for leakage. In this paper, developed the anti-leakage system with stability and convenience of operate.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.488-491
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• 1997

In this paper, a ncw control 'ialvc which can misc air-iraksge pneumatically and compensate pressure drop for an alrho~ st system uas proposed A new control valve called "Pneuniatic C70ntro1 Valve (PCV)" functions as a control valve to compcns;ltc prcssure in thc casc of air-leakage. by using the pure pneummatic control ofpilot pressure. Based on the sirnulation of the proposed PCY, thc experimental system was fabricaied su as to illustrate the efficient pcrformance of the proposed PCV with anti-leakage. Such good perfo~manccs of PCV in the air-hoist system are shown by the simulation. In addition, the simulation bascd design approach presented in this paper can be applied to any hydraulic or pneumatic-hydraulic system.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2008년도 정보통신설비 학술대회
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• pp.93-96
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• 2008

A transmitter (TX) leakage cancellation scheme using a Micro Controller Unit (MCU) is introduced. This paper highlights an adaptive anti-leakage signal generation via an MCU, which plays the key role in reducing the TX leakage signal level. High transmitter-to-receiver (TX-to-RX) isolation is verified with measurement results.

• 전력전자학회논문지
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• 제13권3호
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• pp.221-228
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• 2008

본 논문에서는 BLDC MOTOR를 2상 여자 unipolar PWM방식으로 구동할 때 개방된 상의 역병렬 다이오드를 통해 원치 않는 누설전류의 흐름이 생기는 원인 및 영향을 분석하고 이를 제거할 수 있는 개선된 unipolar PWM 방식을 제안하였다. 개방된 상에 흐르는 누설전류는 속도가 증가할수록, PWM duty가 감소할수록 증가하며 전동기 출력의 손실을 초래한다. 제안된 unipolar PWM방식의 유효성을 시뮬레이션 및 실험을 통하여 검증하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.214-219
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• 2002

As the tangential flow inside the clearance of tribe elements such as bearings and seals is increased as the shaft speed increases, the system stability will be decreased due to the increment of the instability parameter. To reduce the tangential flow inside the clearance of the balance sleeve, anti-swirl injection mechanism is applied. The balance sleeve is used in resisting the axial force induced by impeller in high pressure multi-stage pump. In this paper, total three cases are experimentally investigated; original balance steeve, anti-swirl injection balance steeve with 0 axial degree and anti-swirl injection balance sleeve with 30 axial degree. Experiments are focused in the comparison of vibration level and leakage flow rate. The results clearly shows that the anti-swirl injection balance sleeve with 0 axial degree improves the vibration characteristics. However, the anti-swirl injection balance sleeve with 30 degree aggravates the vibration characteristics. In the standpoint of leakage performance, both anti-swirl injection balance sleeves show the better result than the original balance sleeve.

• 한국소음진동공학회논문집
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• 제12권8호
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• pp.632-638
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• 2002

As the tangential flow inside the clearance of tribo elements such as bearings and seals is increased as the shaft speed increases, the system stability will be decreased due to the increment of the instability parameter. To reduce the tangential flow inside the clearance of the balance sleeve, anti-swirl injection mechanism is applied. The balance sleeve is used in resisting the axial force induced by impeller in high pressure multi-stage pump. In this paper, total three cases are experimentally investigated; original balance sleeve, anti-swirl injection balance sleeve with 0 axial degree and anti-swirl injection balance sleeve with 30 axial degree. Experiments are focused in the comparison of vibration level and leakage flow rate. The results clearly shows that the anti-swirl injection balance sleeve with 0 axial degree improves the vibration characteristics. However, the anti-swirl injection balance sleeve with 30 degree aggravates the vibration characteristics. In the standpoint of leakage performance, both anti-swirl injection balance sleeves show the better result than the original balance sleeve.

• 생약학회지
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• 제21권2호
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• pp.163-172
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• 1990

These studies were conducted to investigate the effects of Tongkwan-San water extract on analgesic, sedatative, anti-inflammatory, blood pressure and vasodilating actions, the relaxing action of isolated ileums and actions on the contact dermatitis induced by picryl chloride and on the leakage of the dye into the peritoneal cavity. The results of these studies were summarized as follows: The analgesic effect of Tongkwan-San was noted. The prolongation of anesthetic time of Tongkwan-San was recognized. Spontaneous motilities of isolated ileum of mice were strongly suppressed by Tongkwan-San. It inhibited the contractions of isolated ileum of mice induced by acetylcholine and barium chloride and the contraction of isolated ileum of guinea-pig induced by histamine. Inhibition of the contact dermatitis induced by picryl chloride was recognized. Anti-inflammatory effects in the paw edema induced by histamine and dextran were significantly shown. The leakage of dye into the peritoneal cavity in mice was significantly inhibited. Hypotensive and vasodilating action due to vascular smooth muscle relaxation were noted in rats and rabbits.

• 한국전기전자재료학회논문지
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• 제13권7호
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• pp.598-606
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• 2000

In this paper we investigated the relation between the surface degradations and anti-pollution characteristics of Room Temperature Vulcanized(RTV) silicone rubber coating that has different roughness through immersing into saline water. We utilized several analytic techniques such as atomic force microscopy(AFM) scaning electron microscopy(SEM) contact angle Salt Deposit Density(SDD) and average leakage current under the condition of salt fog. It is found that the surface roughness of treated RTV silicone rubber increased and the hydrophobicity of sample surface decreased with increasing the duration o immersion into water due to the erosion of base polymer the melting down alumina trihydrate(ATH) and the diffusion of Low Molecular weight(LMW) fluid. Despite the roughness of surface had been increased by water immersion excellant anti-pollution and recovery characteristics were maintained and SDD saturated to 0.1~0.14mg/cm$^2$. The average leakage current under salt fog increased with surface roughness. Measurement of average leakage current will be helpful to investigate surface degradation and lifetime expectation of RTV silicone coating.

• Journal of Chest Surgery
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• 제21권5호
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• pp.899-904
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• 1988

In Behcet syndrome, cardiac involvements are rare and have been reported pericarditis, myocarditis, right heart endocardial fibrosis, right ventricle mural thrombus with pulmonary embolism, active endocarditis, granulomatous endocarditis, conduction disturbance, acute aortic insufficiency, mitral valve prolapse. Our three patients underwent AVR because of aortic insufficiency and ascending aorta enlargement combined with Behcet syndrome. Two patients had mitral regurgitation too. So one underwent MAP and the other underwent MVR concomitantly. One who underwent AVR have been well for 50 months. Another who underwent AVR+MAP and redo AVR due to aortic paravalvular leakage was died of congestive heart failure. The other who underwent AVR+MVR and repeated AVR three times because of aortic paravalvular leakage is in condition of aortic paravalvular leakage. Paravalvular leakage is considered to recur due to progressive dilatation and fragility of aortic root that is the result of pathologic change of Behcet syndrome in it. If Open heart surgery is needed in Behcet`s syndrome during inflammatory reaction is active, postoperative complications such as paravalvular leakage or suture line rupture may be prevented with pre- and postoperative anti-inflammatory management.