• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.10
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• pp.123-129
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• 2010

During the past 2 decades, many electric power companies have been searching various solutions in order to supply power with economical and more efficiency in the present transmission utilities. Most interesting method to increase the line capacity of overhead transmission lines without constructing any new line might be to adapt Dynamic Line Rating(DLR). Specified rating is normally determined by any current level, not by conductor temperature. Although specified rating is essential to design transmission line, dip may be the most important factor in limiting transmission capacity. Transmission lines built by the oldest dip criterion among the 3 different design criteria for conductor dip are nearly over one-half of all Kepco's transmission lines. This paper describes an up-rating method for those transmission lines in order to apply DLR technique. Based on limit dip conductor temperature and current of the transmission lines, limitation performance and effectiveness in applying DLR with weather model are analyzed. As a result of analysis, it can be shown that an improved method could be effectively used for increasing the line rating of old transmission line which was built by the design criterion with low dip margin.

• Korean Journal of Computational Design and Engineering
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• v.12 no.6
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• pp.466-471
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• 2007

Brackets for an automatic transmission are usually used to connect the transmission with adjacent components in a vehicle. Fillet areas of brackets are one of the most important areas to design the brackets because the areas are easily fractured when the brackets are subjected to external loads. In this study, a new design around the fillet area of the bracket is suggested and improved effects of the proposed design are proved through the comparison of safety factors with the current design. The safety factors are calculated through the fatigue analysis via a commercial code, FEMFAT.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.11
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• pp.88-93
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• 2000

Recently the gear design focuses on the optimal design to extract the design factors from the vehicle transmission that is required to equip the powerful, speedy and silent characteristics. In this study, we had determined modules($m_n$) and face widths (b) to sustain strengths of contact and bending. The pressure angle ($\alpha$) and the helix angle ($\beta$) also had been obtained from the constraint of a contact ratio ($\varepsilon) on helical gears. Through the optimal design algorithm suggested in this study, the design factors were calculated on vehicle transmission gears and those determined factors were able to firm a suitability of the design.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.4
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• pp.151-155
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• 2006

HVAC transmission lines must be designed to satisfy environmental regulations. Therefore it is necessary to pre-evaluate environmental problems for transmission line designer using prediction program. In this study, environmental design software, TLCALC(Transmission Line CALCulation) for transmission lines was developed as a comprehensive window program. It has 6 modules that are audible noise, radio noise, television noise, magnetic field, electric field and conductor surface gradient. TLCALC solved a few problems in use of the existing foreign tools and took several advantages as follows; (1) It is a common tool that solves calculating limitations of foreign formulas, (2) It has wide application ranges and enhances accuracy of prediction. (3) It can be applied to almost transmission line configurations in Korea. (4) Experienced designers can get the results of calculation within about 15 minutes. Because the use of TLCALC is easy and practical, this program will be usefully applied to the environmental friendly design and construction of transmission lines. In the future, it is expected that public complaints and social environmental cost will be reduced by the use of TLCALC.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.11
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• pp.24-34
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• 2019

An automotive automatic transmission is a popular power-transmitting device in passenger vehicles, as it provides various speed ratios for diverse driving conditions with easy manipulation and smooth gear shifting. The transmission is mainly composed of input and output shafts, planetary gear sets, brakes/clutches, and housing, and it yields multiple forward gears and one reverse gear by actuating the shifting devices of the brakes and clutches. In developing a new transmission, kinematic configurations of a transmission, which presents a brief structure and actuation schemes for speed ratios, need to be checked to determine if the structure can be assembled in a layout. It is impossible for a transmission concept having any interference in connecting main components to be developed further in the design process, since connection interference leads to failure of a layout design in the 2-D plane. In this research, an analysis of the assemblability of a front-wheel drive automatic transmission is carried out on an example concept design by applying the vertex addition algorithm based on graph theory.

• Journal of Drive and Control
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• v.10 no.2
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• pp.30-36
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• 2013

Tractor is a farm vehicle that is designed to provide a high tractive effort at low speed. It is used for versatile agricultural tasks such as hauling a trailer, tillage, mowing and construction work. Most older tractors use a manual transmission. However, as the intensity of work increases, tractors equipped with automatic transmission become popular due to the work convenience. In order to give the operator a large degree of control in field work, 24 gears with automatic 8-speed and manual 3-speed are arranged in transmission. This paper deals with the gear train that is designed for 8-speed automatic transmission by the engagement of multi-disk clutches. The gear ratio for each speed as well as power transmission mechanism is analyzed through velocity analysis. In addition, constraints of mesh gear ratio are derived by investigating the power flow path in velocity diagram for the given 8-speed gear ratio.

• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.276-278
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• 1996

The breakdown Process in large gaps is greatly influenced by the gap geometry. Therefor full scale test are essential for the economical and reliable air insulation design. For switching surge design of 765 kV double circuit transmission line KEPRI is carrying the verifying tests using impulse voltage generator at Gochang test site. In this paper, the intermediate results of verifying tests are presented and the switching surge design criteria of 765 kV transmission tower flashover paths are discussed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.690-692
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• 2014

To identify characterization of a simple extension chamber that have the two internal partition, produce the curve to estimate the transmission loss without the computer analysis. For helpful for internal optimum design, identify the characteristic of internal partition on transmission loss. Made estimated transmission loss curve by function of relationship of internal partition and transmission. Check the similarity of predicted transmission loss and analysis transmission loss. Usage of the predicted transmission loss made by relationship of internal partition and transmission loss is good information to place the internal partition so as to maximize the transmission loss on target frequency at optimal design on muffler.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.3
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• pp.242-247
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• 2003

This paper deals with an optimal design methodology for an automatic transmission lever using a genetic algorithm. A component of an automatic transmission lever has been designed sequentially in the industry, but the study presents a new design method to consider the design parameters of components simultaneously. A genetic algorithm approach is described to determine a set of design parameters for an automatic transmission lever. We have attempted to model the design problem with the objective of minimizing the angle variation of detent spring subject to constraints such as modulus of elasticity of steel, geometry of shift pipe. and stiffness of spring. The proposed method can give the better design alternative.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.1
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• pp.97-103
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• 2009

The process design of forward Extrusion and Upsetting of Axi-symmetric part has been studied in this paper. During the cold forging product; auto transmission Solenoid Valve part, the defects such as folding and under-fill can be appeared by the improperly controlled metal flow. In this study, to reduce the folding and under-fill the design of experiments has been used to find out the significant design variables in the design of forging process. This paper deals with an Process Planning with which designer can determine operation sequences even after only a little experience in Process Planning of Multi-Former products by multi-stage former working. The approach is based on knowledge-based rules, and a process knowledge-base consisting of design rules is built. Based on the systematic procedure of process sequence design, the forming operation of cold forged auto transmission Solenoid Valve part is analyzed by the commercial Finite Element program, DEFORM/2D.