• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2910-2916
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• 2011

Environmental conservation is becoming the major conversation topic in the 21st century, the era of environment. In the Law for the Preservation of Water Quality, article 53 states "A business unit which is doing business causing pollution caused by non-point pollutant or builds waste water discharge facilities, should report the installation of the non-point pollutant and install the required pollution control facilities". Environmental pollution caused by oil leaks during operation or maintenance has been found in the railway sector. Especially, rolling stock depot is most likely to be affected by environmental pollution. Therefore, in this paper We have investigated non-point pollutant in the rolling stock depot area and have studied adequate disposal method to minimize the effect of the non-point pollutant, hoping to supply the preliminary data for building an environment-friendly rolling stock depot.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.5
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• pp.815-822
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• 2003

The ring rolling process involves not only three-dimensional non-steady material flow and continuous change of radius and thickness of the ring workpiece but also heat transfer among workpiece, rolls and environment. In this study, deformation and heat transfer analyses were conducted by using the three-dimensional thermo-rigid-plastic finite element method. Three cases of plain ring rolling process were, respectively, simulated for the predictions of roll forces and the highest temperature zone during the aluminum process that ductile fracture often occurs. In addition, to prevent fishtail phenomena of the ring workpiece, axial rolls were used for this study.

• Tribology and Lubricants
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• v.12 no.4
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• pp.43-51
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• 1996

Rapid increase of refrigeration & air-conditioning system (r & a system) in modem industries brings attention to the urgency of research & development as a core technology in the area. And it is required to the compatibility problem of r & a system to alternative refrigerant for the protection of environment. Then, it is requested to study the lubrication characteristics of refrigerant compressor which is the core technology in the r & a system. The study of lubrication characteristics in the critical sliding component is essential for the design of refrigerant compressor. Therefore, theoretical investigation of the lubrication characteristics of rotary compressor for r & a system is studied. The Runge-Kutta method is used for the analysis of the behavior of rolling piston in the rotary compressor. The results show that the rotating speed of shaft and the discharge pressure have an important effect upon the angular velocity of the rolling piston. This results give important basic data for the further lubrication analysis and design of the rotary compressor.

• Korean Journal of Head & Neck Oncology
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• v.26 no.1
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• pp.19-23
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• 2010

Objectives : In parotidectomy, facial nerve dissection technique had been evolved for its safety. Surgical landmarks are important and good guides to facial nerve detection. Conventional exposure and release of the nerve requires hemostat for elevation of parotid tissue from nerve and #11 blade for cutting the parotid away from the nerve. Material and Methods : The rolling the parotid tissue over the nerve after dissecting with Metzembaum scissors instead of knife, lessen pulling trauma and nerve cutting by knife. Eleven superficial parotidectomies since June 2009 were done with rolling technique and preliminary report is presented. Results : Total 11 parotidectomies were done using proposed technique with tolerable complications(temporary facial dysfunction in 4 cases). Conclusion : Rolling method using metzembaum scissors could be applied to parotid operation.

• Transactions of Materials Processing
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• v.10 no.2
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• pp.130-136
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• 2001

The mathematical set-up model was developed to reduce the mechanical property deviation in annealed and slightly rolled steel strip. The mechanical peculiarities of skin pass rolling process, such as high friction value and non-circular contact arc, low reduction and non-negligible entry and exit elastic zones as well as central restricted deformation zone are all taken into account. The deformation of work rolls is calculated with the influence function method and arbitrary contact arc shape is permitted. The strip deformation is modeled by slab method and the entry and exit elastic deformation zones are included. The strip restricted deformation zone near the neutral point is also considered. It was revealed that the new model has better accuracy than present regression model by statistical analysis with actual mill rolling data.

• Transactions of Materials Processing
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• v.25 no.2
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• pp.130-135
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• 2016

Rolled products often have residual stresses or strip waves that are beyond the customer’s tolerance. To resolve this problem, skin-pass rolling is widely used during post-processing of such products. Because a short contact length compared to the strip width is a characteristic of skin-pass rolling, several numerical analyses have been previously conducted based on a two-dimensional approach. In the current study, a series of simulations was conducted using numerical analysis of three-dimensional elastic-plastic finite element method.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.12
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• pp.2096-2105
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• 1997

A parallel approach using a network of engineering workstations is presented for the efficient computation in the elastoplastic analysis of strip rolling process. The domain decomposition method coupled with the frontal solver for elimination of internal degrees of freedom in each subdomain is used. PVM is used for message passing and synchronization between processors. A 2-D plane strain problem and the strip rolling process are analyzed to demonstrate the performance of the algorithm and factors that have a great effect on efficiency are discussed. In spite of much communication time on the network the result illustrates the advantages of this parallel algorithm over its corresponding sequential algorithm.

• Tribology and Lubricants
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• v.17 no.2
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• pp.138-145
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• 2001

The rolling piston type rotary compressor has been widely used for refrigeration and air-conditioning systems due to its compactness and high-speed operation. The present analysis is a part of research program directed toward maximizing these advantages of refrigerant compressors. The study of lubrication characteristics in the critical sliding component is essential for the design of refrigerant compressors. Therefore, theoretical investigation of the lubrication characteristics of a rotary compressor used for refrigeration and air-conditioning systems is studied. Newton-Raphson method is used for the partial elastohydrodynamic lubrication analysis between vane and rolling piston in the rotary compressor. The results show that the rotational speed of a shaft and the discharge pressure influence significantly the friction force and the energy loss between vane and rolling piston.

• Journal of Advanced Marine Engineering and Technology
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• v.24 no.4
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• pp.405-413
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• 2000

This paper present study on the application of sound pressure and vibration signals to detect the presence of defects in a rolling element bearing using a statistical analysis method. The well established statistical parameters such as the crest factor and the distribution of moments including kurtosis and skew are utilized in this study. In addition, other statistical parameters derived from the beta distribution function are also used. A comparison study on the performance of the different types of parameter used is also performed. The statistical analysis is used because of its simplicity and quick computation. Under ideal conditions, the statistical method can be used to identify the different types of defect present in the bearing. In addition, the results also reveal that there is no significant advantages in using the beta function parameters when compared to using kurtosis and the crest factor for detecting and identifying defects in rolling element bearings from both sound and vibration signals.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.928-934
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• 2005

In this paper, we propose the ergonomic design method in shape design applicable for Advanced Urban Transit System. Human's sensitivity and User Interface of rolling stock investigated ergonomic studies of several type. The sensibility engineering design made approach of user center design in rolling stocks design. Therefore, we have application to properly of ergonomic design element in rolling stock design. we expert visual design and user interface help greatly in excellent rolling stock design.