• Journal of the Korean Institute of Gas
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• v.10 no.3 s.32
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• pp.27-33
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• 2006

This paper investigates leak effect on the outlet pressure at pipeline exit. A modified Weymouth equation(including inclination effect) was used for this study. To investigate leak effect, outlet pressure and ratio of outlet to inlet pressure were compared between no leak and leak conditions for horizontal, upward and downward flows, respectively. Then, effects of leak location as well as leak rate on the outlet pressure were also investigated for all pipeline inclinations.

• Journal of Trauma and Injury
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• v.30 no.2
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• pp.63-65
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• 2017

Standard open procedures for resection of the first rib in thoracic outlet syndrome can prove to be quite difficult with extensive incisions. A minimal invasive procedure can also be painstaking, but provides an attractive alternative to the more radical open procedures. We report the details of the technique with direct video footage of the procedure performed in a 41-year-old man with thoracic outlet syndrome done entirely by thoracoscopic methods.

• Journal of Korea Multimedia Society
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• v.17 no.7
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• pp.879-885
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• 2014

This paper designs and implements the 2 plug type standby power control outlet based on IEEE 802.15.4 using Zigbee and IPv6 network in order to reduce the standby power to the user. The standby power control system is consisted of direct power and standby power plug. Also this system can communicate bidirectionally in wireless because built-in wireless communication modules. One gateway is linked with many standby power control outlet in wireless. Each standby power control outlet executes the operation needed in power control independently. Also each standby power control outlet has its own power can be detected in real time independently of the power can be controlled.

• International Journal of Fluid Machinery and Systems
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• v.1 no.1
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• pp.109-120
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• 2008

An innovative method of changing a centrifugal low specific speed pump performance and pressure fluctuation by applying outlet flaps to impeller exit has been investigated. The outlet blade edge section corresponds to the trailing edge of wing on the circular-cascade, which dominates the pump performance and pressure fluctuation. Computational fluid dynamics (CFD) analysis of the entire impeller and volute casing and an experimental investigation are conducted. The pressure fluctuation and the vibration of the shaft are measured simultaneously. Kurtosis is applied as a dimensionless parameter with which the unevenness of velocity distribution at impeller outlet is indicated. The influence of the flaps on the pressure fluctuation is explained by the kurtosis. This paper presents a theoretical method of predicting the pump performance related to the attachment of a flap at impeller outlet.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11b
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• pp.114-117
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• 2005

In the reactive concentric resonator, perforated inner tubes are widely used for various purposes related to noise reduction, flow guiding, and structural aspects. Perforation distribution patterns influence both the acoustic performance and mechanical performance. In this study, the influence of distribution patterns on acoustic performance are explained by adopting the concept of extended inlet/outlet length. Predicted transmission with varying extended inlet/outlet length is compared with prediction by varying distribution patterns. The transmission loss difference due to perforation distribution patterns can be explained by changing the extended inlet/outlet length of the uniformly perforated resonator.

• Journal of Chest Surgery
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• v.33 no.4
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• pp.316-319
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• 2000

Double-outlet left ventricle with ventricular septal defect and pulmonary stenosis was conventionally repaired with extracardiac conduit or pulmonary artery translocation. Here, we report an anatomically repaired double-outlet left ventricle without extracardiac conduit or pulmonary artery translocation in an 11 month old patient who had undergone palliative systemic-pulmonary shunt at a nonatal period. The location of ventricular septal defect, both great arteries and coronary arteries made it possible to reconstruct the right ventricular outflow tract using on-lay patch after incision and undercutting the tissue between the ventriculotomy and the pulmonary arteriotomy.

• Journal of KSNVE
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• v.9 no.5
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• pp.914-921
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• 1999

There are many theoretical investigations to analyze higher order mode of reactive type single expansion chambers with offset inlet/outlet locations. But the conventional method has the restriction that the ratio between the area of inlet(or outlet) pipe and that of chamber must be natural number. In the paper, a new method was suggested to apply the Kim's method to silencer with circular cross-section. Not only the offset location but also the magnitude of cross-section area of inlet/outlet pipe can be considered by the suggested method. The predictions by this new method also compared with those by the finite element method and Munjal's method in order to verify the accuracy of the suggested method presented here.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.4
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• pp.151-159
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• 1998

The heavy equipment such as tracter has been studied to improve rather the performance of engine than comfort. The mufflers of tracters have various specifications according to their uses. The exact analysis of various mufflers is needed to reduce the level of exhaust moise, a major noise source of engine, to improve the ride quality of tracter. In this study, a software based on Green's function is developed to predict the performance of sound transmission loss for a muffler according to the locations of inlet/outlet pipes. The locations of inlet and outlet pipes can be fixed at different position individually. The conventional muffler has the locations of inlet/outlet pipes on the direction of longitudinal axes. On other hand, the inlet and outlet pipes may be located at the circumferential surface of a test muffler such as one of tracter. The software is verified by analysis and experiment on current muffler of tracter and the improvement technique is proposed to reduce the level of exhaust noise.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.70-77
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• 2004

Comprehensive investigation on the outlet's geometric shapes of a centrifugal blower with higher inlet resistance than an atmospheric pressure is carried out for improvements of its performance. Most unwanted behaviors of such blower are pulsating flows because of unbalance between inflows and outflows in a scroll casing. In order to reduce this undesirable phenomenon a triump is made for both the shape of outlet duct and an accessory structure inserted in the outlet port of the blower. The modification on the shape is concerned with the contraction of cross sectional area and the attached structure is for an intentional obstruction to cause a flow resistance. The details of the modification are examined for different cases and results. The methodologies for the work are performance evaluations including noise level and velocity measurements with PIV Consequently, the performance of improved system is close to that of the system operating with atmospheric pressure at the inlet.

• International Journal of Fluid Machinery and Systems
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• v.8 no.4
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• pp.311-317
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• 2015

It is difficulty to calculate velocity circulation in centrifugal pump impeller outlet accurately. Velocity circulations of a double-blade pump impeller outlet were calculated with Stodola formula, Weisner formula and Stechkin formula. Simultaneously, the internal flow of impeller for the double-blade pump were measured with PIV technology and average velocity circulations at the 0.8, 1.0 and 1.2 times of design flow were obtained. All the experimental values were compared with the above calculation values at the three conditions. The results show that calculation values of velocity circulations with Weisner formula is close to the experimental values. On the basis of the above, velocity circulations of impeller outlet were corrected. The results of experimental verification show that the corrected calculation errors, whose maximum error is 3.65%, are greatly reduced than the uncorrected calculation errors. The research results could provide good references for establishment of theoretical head and multi-condition hydraulic optimization of double-blade pumps.