• 동력기계공학회지
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• 제5권3호
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• pp.56-63
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• 2001

A slitter is a sort of machinery to cut sheet materials in rolls continuously in the longitudinal direction. Recently slitter line users have requiring higher quality and precision in products in addition to high productivity. A finite element analysis has been performed to investigate the effect of processing factors on shear planes in the slitting of Shrinkage Band(S,K.B.). For the analysis, Hot-dip 55% aluminum-zinc alloy-coated steel sheets and coils(SAZCC) is selected as a material. The results obtained are that deformation was concentrated along the very narrow zone and the maximum slitting load decreases by increasing the knife clearance. Also effective strain decreases according to the clearance increases.

• 설비공학논문집
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• 제13권6호
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• pp.440-447
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• 2001

This study investigate experimentally the effect of in height, thickness, and clearance on the boiling heat transfer. The heat surfaces having copper fin array is tested for pool boiling. The gas-liquid exchange interference is investigated based on fin array clearance. These test results can be applied to the design of tube bundle system. The fin height of 2 mm is found to be effective. Effects of heat transfer promotion reaches the highest level when the fin clearance is 0.5mm. Also, heat flux is increased when the fin thickness is smaller. But0.2 mm fin thickness is highly recommended.

• 한국산학기술학회논문지
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• 제14권12호
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• pp.6060-6065
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• 2013

유효 전단면의 크기를 최대가 되도록 하기 위해서는 다이 롤 높이의 최소화가 매우 중요하다. 본 연구에서는 V-링 압입량의 변화와 클리어런스의 변화에 대한 다이 롤 변화를 연구하였다. V-링 거리를 2mm로 고정하고 클리어런스가 다른 다이인서트를 적용할 수 있는 파인블랭킹 금형을 제작하여 전단해석과 실험을 진행하였다. 각 실험으로부터 시편을 채취하여 다이 롤 높이를 분석한 결과 V-링의 압력이 재료의 유동을 효과적으로 억제하고 펀치와 다이 사이의 클리어런스가 재료 두께에 대하여 1%의 경우가 다이 롤 높이가 낮게 됨을 알 수 있었다.

• 한방안이비인후피부과학회지
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• 제28권4호
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• pp.196-207
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• 2015

Purpose : To observe effects of Korean Medicine treatment for genital warts.Methods : In a single private clinic from February 2014 to February 2015, we did retrospective chart review for 326 patients with genital warts who had been treated by Korean Medicine. Korean Medicine treatment included herbal treatment and herbal ointment.Results : A total of 326 patients were enrolled in this study: 62.7%(n=219) male, 32.8%(n=107) female. In the type of diagnosis, new diagnosis was 45.4%(n=148) and recurrent disease was 54.6%(n=178). Complete clearance was achieved 63.2%(n=206) and treatment period was 3.5 months(range:1-9). Partial clearance-good was 15%(n=49), partial clearance-poor was 4.9%(n=16), non response was 16.9%(n=55) and the average treatment period was 4.3 months(range:1-14). In complete clearance group, female and the prevalence of less than 1 year were statistically significant(p<0.05). There was no recurrence of genital warts after TKM treatment during follow-up period(4-13months).Conclusion : This study suggest that Korean Medicine may be an effective treatment for genital warts.

• 대한한방내과학회지
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• 제41권3호
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• pp.502-507
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• 2020

This study aimed to investigate the effect of Hwanglyeonhaedok-tang on the clearance of vancomycin-resistant Enterococcus (VRE) colonization in a patient with traumatic subarachnoid hemorrhage and subdural hematoma. A 73-year-old man who was diagnosed with traumatic subarachnoid hemorrhage and subdural hematoma with isolation of VRE colonization was administered Hwanglyeonhaedok-tang and followed up with a rectal swab VRE culture every week. After treatment with Hwanglyeonhaedok-tang, VRE colonization was no longer detected. This case report proved that Hwanglyeonhaedok-tang could be an effective treatment for clearance of VRE colonization in a patient with traumatic subarachnoid hemorrhage and subdural hematoma.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1997년도 제25회 춘계학술대회
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• pp.111-121
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• 1997

The stability of a rotor-bearing system supported by swirl-controlled hybrid journal bearing with pair-type angled injection orifices is investigated for improvement of the whirl frequency ratio by allowing effective control of the tangential flow inside the bearing clearance, i.e., by achieving more freedom in controlling strength and direction of the supply tangential flow inside the bearing clearance. It is suggested that the system instability can be improved through the change of bearing dynamic characteristic parameters with the swirl control. The orifice diameter d$_0$ and recess injection angle $\alpha$ along with combinations of swirl/anti-swirl supply pressures and directions (3.0-3.0MPa, 4.0-2.0MPa, 2.0-4.0MPa) are selected for design parameters for swirl-controlled effective factors dependent on journal speeds (3000, 9000, 15000, 21000 rpm). It has been found that the orifice diameter do shows strong effects on effective maneuverability of direct-stiffness and direct damping values, while recess injection angle $\alpha$ results in substantial magnitude and direction of cross-stiffness. Specifically, recess injection parameters which are functions of angle of orifice feeding flow and recess dimensions showed very feasible effect on the stability of swirl-controlled rotor-bearing system.

• Tribology and Lubricants
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• 제13권3호
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• pp.63-72
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• 1997

The stability of a rotor-bearing system supported by swirl-controlled hybrid journal bearing with pair-type angled injection orifices is investigated for improvement of the whirl frequency ratio by allowing effective control of the tangential flow inside the bearing clearance, i.e., by achieving more freedom in controlling strength and direction of the supply tangential flow inside the bearing clearance. It is suggested that the system instability can be improved through the change of bearing dynamic characteristic parameters with the swirl control. The orifice diameter $d_0$ and recess injection angle $\alpha$ along with combinations of swirl/anti-swirl supply pressures and directions (3.0~3.0 MPa, 4.0~2.0 MPa, 2.0~4.0 MPa) are selected for design parameters for swirl-controlled effective factors dependent on journal speeds (3000, 9000, 15000, 21000 rpm). It has been found that the orifice diameter $d_0$ shows strong effects on effective maneuverability of direct-stiffness and direct damping values, while recess injection angle $\alpha$ results in substantial effects on the magnitude and direction of cross-stiffness. Specifically, recess injection parameters which are functions of angle of orifice feeding flow and recess dimensions showed very feasible effect on the stability control of swirl-controlled rotor-bearing system.

• 대한산업공학회지
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• 제37권2호
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• pp.153-162
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• 2011

The demands of complicated data communications have issued a new challenge to port logistics systems. Customers expect ports to handle their generated administrative data while a vessel is docked in a port. One port logistics system, known as the Vessel Clearance Process (VCP), manages large numbers of documents related to port of entry. In the VCP, information flows through many organizations such as the port authority, shipping agents, marine offices, immigration offices, and others. Therefore, for effective management of the Business Process (BP) of the VCP, a standardized method of BP modeling is essential, especially in heterogeneous system environments. In a port, according to port policy, terms and data are sued that are similar to but different from those of other logistics partners, which hinders standardized modeling of the BP. In order to avoid tedious and time-consuming document customization work, more convenient modeling of BP for VCP is essential. This paper proposes an ontology-based process similarity measurement to assist designer for process modeling in port domain, especially VCP. We expect that this methodology will use convenient and quick modeling of port business processes.

• International Journal of Fluid Machinery and Systems
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• 제4권2호
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• pp.217-222
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• 2011

The rotordynamic fluid forces acting on a closed type impeller in whirling motion were measured and the influence of the clearance geometry on the stability of the impeller was examined. At small positive whirling speed, the rotordynamic forces acted as destabilizing forces for all casings. A small clearance between the shroud of the impeller and the casing caused large fluid force, but did not change the destabilizing region. Radial grooves in the clearance were effective for reducing the fluid forces and destabilizing region due to the reduction of the circumferential velocity without the deterioration of the pump performance. A rotating phenomenon like a rotating stall of the impeller occurred at low flow rate and the resonance between it and the whirling motion led to a sudden increase in force at the whirling speed ratio of 0.7.

• 한국정밀공학회지
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• 제30권12호
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• pp.1327-1333
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• 2013

Air bearings are widely used in precision stages because of low friction and high motion accuracy, however, they suffer from low stiffness in comparison with rolling bearings or hydrostatic bearings. So, several preloading methods using weight, magnet and vacuum force, and opposing pads have been used to increase the stiffness of the air bearings. In this paper, pressure distributions of the vacuum preloaded porous air bearings are calculated using the proposed method. And then, the load capacity and stiffness are analyzed. For the vacuum preloaded air bearings, the stiffness is increased owing to reduced bearing clearance by vacuum force. The simulation results indicate that variation of vacuum pressure with clearance in the vacuum pocket gives rise to low stiffness, so the vacuum pocket should be designed for pressure to be constantly maintained regardless of the bearing clearance by means of large effective pumping speed.