• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2003.05a
• /
• pp.549-554
• /
• 2003

Recently, the ride comfort problem becomes increasingly important because of today's needs for train speedup. The concept of ride comfort is equivocal. Generally, it is defined as the body vibration. The prototype of Korean high speed train (KHST), composed of two power cars, two motorized cars and three trailer cars, has been designed, fabricated and tested by the domestic researchers. In this paper, the ride comfort has been reviewed by the experimental method. The on-line test of KHST has been carried out up to 260km/h in the KTX line and proved that KHST has no problems from the viewpoint of the comfort ride at this speed. And the ride index lot KHST has been predicted at 300km/h and 350km/h by fitting curve.

• Proceedings of the KSR Conference
• /
• 2006.11b
• /
• pp.1575-1580
• /
• 2006

High speed and large transfer capability of railroad has been an important issue in Korean since KTX opening at 2004. Improvement projects for railway electrification are progressed in the conventional line as well as high speed line because various operation plan is performed such as interaction between high speed line and conventional line and operation of tilting train etc. Especially, railway electrification has many advantages which are cost effective and eco-friendly. But it also has some problems such as construction costs and accidents due to electrification. Therefore this paper developed measuring index of electrification railway benefit. By comparing between diesel and electrical locomotive, the operations of before and after the electrification and measurements quantitative index such as energy efficiency, enlargement of transfer capability, environmental pollution and maintenance and efficiency of operation is presented. In the future, Overall benefit and cost of railway electrification will be analyzed.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
• /
• v.3 no.2
• /
• pp.26-32
• /
• 2004

This paper represents analysis on domestic technical regulation of high speed power line communications(PLC). Also it gives comparison of regulations for several countries which include U.S., Europe, and Japan. Power line communications radiates harmful interference in below 30MHz. This may intervene other radio equipments. The technical regulation must protect interference and provide clean radio environment. Finally this paper gives the proposal which is drafted by field tests for introducing high speed PLC.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.65 no.3
• /
• pp.183-187
• /
• 2016

Recently, power demand has been increasing every year according to variation of electrical equipments and temperature rise in summer season. So, much more overhead line is being demanded to copy with increasing power demand and operate reliable power system. This paper analysis the characteristics of long span overhead transmission line using special high-tension wire in such as a safety factor, coefficient of elasticity, and the coefficient of linear expansion. Based on the analysis, we proposed the effectiveness of special high-tension wire having much more advantages with respect to height of steel tower and dip compared with conventional ACSR in long span overhead transmission line.

• Archives of Plastic Surgery
• /
• v.36 no.5
• /
• pp.649-653
• /
• 2009

Purpose: Double - eyelid operation is one of the most common cosmetic operations among Korean patients. In such operations, however, the complexity of and individual differences in the patients' anatomical structures may cause various complications, such as asymmetry, retraction of the eyelid, and the occurrence of a high fold. A high fold occurs frequently, and its correction is not very simple. Many methods have been developed to correct it, and among these, the operation involving the excision of the skin between the previous double - eyelid line and the new double - eyelid line is usually selected by plastic surgeons. In many cases, however, patients have insufficient eyelid skins for this operation. In this study, the authors introduce an operation procedure for high - fold correction that does not involve skin excision Methods: From June 2005 to June 2009, 246 cases were treated with this procedure. After the incision of the new double - eyelid line, dissection was done between the previous scar tissue and the levator aponeurosis. Then the orbital septum, orbital fat or the retro - orbicularis oculi fat was slid down and sutured with a tarsal plate. Such sutures were repeated at four to five points, including the lateral and medial limbus, to prevent the reattachment of the previous scar and to create a new double - eyelid line at the end of the orbital septum. Results: Most of the high - fold patients were satisfied with the procedure described above. Their previous scar was hidden under the new double - eyelid line after the operation. In the six cases, the scar was visible in the patients who had a very high and deep inner line. As such, scar revision was undertaken three months after the operation. It is known that scar revision is also required after an operation involving skin excision in the case of a very high inner - eyelid line. Conclusion: This method is an appropriative procedure for high - fold correction for patients who have insufficient upper - eyelid skin.

• Korean Journal of Human Ecology
• /
• v.13 no.5
• /
• pp.787-798
• /
• 2004

This research was designed to compare clothing fabric images between on- and off-line by fabric types and its characteristics. 125 subjects who have a fashion design major evaluated the fabric image of various 16 kinds of specimens on- and off-line. Frequency, x2-test, t-test, and Pearson correlation were used for statistical analysis by SPSS WIN 11.0. The results of this study are as follows: 1. The advantage of on-line shopping includes low price and purchasing convenience, etc. On-line shoppers mostly purchase clothing items, such as T-shirt and slacks. In most cases, texture of fabrics provides a main cause for the shoppers' discontentment with internet shopping. 2. The results of t-test for the difference of the evaluation score show that plain or pile weave and highly thick or thin fabrics-for example, Organdy, Corduroy, Nylon Taffeta, Plush, etc.-have a large difference between on-and off-line image. On the other hand, medium-thick twill weave-for example, Tweed, Flannel, etc.-or patterned weave-Chiffon, Dobby fabric, etc.-shows a small difference. 3. The results of correlation of the evaluation score indicate that wool twill fabrics like Tweed, Saxony, and Polafleece show a high correlation between two kinds of evaluation score. In texture preference, no correlation exists between on-line and off-line. 4. With an analysis on fabric image evaluation by fabric characteristics, smooth, shiny pink Satin was found the most positively-evaluated item in all evaluation fields except in pattern preference and individuality. On the other hand, thick olive green Corduroy was evaluated most negatively in the fields of elegance, luxury, and feminine. 5. When compared with real ones, thin fabrics provide a different on-line fabric image. For example, Nylon Taffeta and Organdy were evaluated positively on-line because of luster and pastel tone color. However, lusterless uneven cotton Seersucker was evaluated negatively. 6. Real fabrics preference is more negative than on-line ones. In addition, patterned or unique fabrics display a high agreement between the two kinds of images.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.20 no.4
• /
• pp.407-411
• /
• 2011

The technology of line heating has evolved in various methods. Among them, fossil fuels like ethylene gas and LPG(Liquid Petroleum Gas) are widely used due to their simple utility. In the meantime, the technology implementing high frequency for line heating has also been developed continually, but its manufacturing technology or application includes lots of problems by now. One of the main characteristics of line heating using conventional technolob'Y is the quenching effect followed by heating process. On the other hand, hydrox gas which is mixed by hydrogen and oxygen is a prominent candidate for an application without above shortcomings. Especially, it is found that line heating using hydrox gas is tremendously effective taking low cost as well as low noise. In this paper, a small cell with high efficiency which can minimize installing space is developed to deal with the problem installing in narrow place. Experiments to prove the validation, efficiency and effectiveness is carried out by characterizing in the line heating of steel. It is found that the energy saving of using hydrox gas for line heating is significant and that the deviation performance is reduced by 78~89%. Furthermore, the noise is also reduced as amount of 18.3% though the heating time is not too different.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.52 no.12
• /
• pp.675-683
• /
• 2003

This paper describes the correction strategy of an overcurrent relay applied in the linked line for interconnecting wind farm with utility power networks in order to improve the capability of a fault detection. The fault current measured in a relaying point might vary according to the fault conditions. Generally, the current of the line to line fault or the line to ground fault in the linked line is much higher than the set value of protective relay due to the large fault level. However, when the high impedance fault occurs in the linked line, we can't detect it by conventional set value because its fault level may be lower than the generating capacity of wind farm. And, the protective relay with conventional set value may generate a trip signal for the insertion of wind turbine generators due to the large transient characteristics. In order to solve above problems and improve protective relaying algorithms applied in the linked line, we propose a new correction strategy of the protective relay in the linked line. The presented method can detect the high impedance fault which can't be detected by conventional relay set value and may prevent the mis-operation of protective relay caused by the insertion of wind farm.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.20 no.8
• /
• pp.86-92
• /
• 2021

As interest and demand for high value-added industries, including the global automobile and aerospace industries, have increased recently, demand for line centers with excellent performance that can respond to the production system for producing high value-added products is also rapidly increasing. A line center improves productivity based on the installed area using a multi-spindle compared to a conventional machining center. However, as the number of spindles increases, the weight increases and results in structural problems owing to the heat and vibration generated by each spindle. Therefore, it is necessary to improve machining precision through the structural improvement of the line center. This study presents research on the stabilization design of the line center through structural stability analysis through structural analysis to develop a compact multi-axis line center. An optimization model of the line center has been proposed to improve the processing precision and increase the rigidity by performing weight reduction based on the structural analysis results.

• Proceedings of the Korea Society of Design Studies Conference
• /
• 2000.11a
• /
• pp.32-33
• /
• 2000

정보화 시대의 도래와 더불어 디자인 환경 역시 크게 변하고 있다. 디자인 환경의 변화에 영향을 주는 요인 중의 하나로 고가치 기업(high value enterprise)이 증가하는 추세를 꼽을 수 있다. 산업 시대의 상징이던 "양적 게임(volume game)"이 정보화시대에는 "질적 게임(value game)"으로 바뀌고 있는 것이다. (중략)