• Journal of the Korean Institute of Gas
• /
• v.24 no.2
• /
• pp.9-14
• /
• 2020

This paper is a purpose to study the failure examples for a large bus vehicle fire. The first example, the researcher certified the fact that the absorbing material break away from the upper side of engine room because of weaken durability and the fire was produced in engine. The second example, it sought the fact that the fire breaks out by electric short because of over-load of compressor. The third example, it found the fact that the fire took place by heating of bellows upper part that was connected with muffler and exhaust manifold. The fourth example, it knew the fact that the fire occurred because of the electric short inside junction box of crash body part that was located to driver seat rightside. Therefore, the fire of a large bus occurring by decrepit of absorbing material and electric short have to thoroughgoingly manage the damage and dangerousness if it happens.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.9
• /
• pp.418-424
• /
• 2017

Magnesium has a higher specific strength than other metals and is widely used industry wide due to its excellent vibration absorption ability and electromagnetic wave shielding property.For example, it is used for automobile parts such as car seat frames and cylinder heads, and is widely used in electronic products such as notebook cases and mobile phone cases. In addition, it is in the spotlight as a bone-implant material used to assist in the treatment of damaged bones when the bones are cracked or broken. Currently, Ti alloy, stainless steel and Co-Cr-Mo alloy are used as the implant material, and the Mg alloy remains in research stage. The current problem with bone implant implants is that the patients must undergo reoperation to remove the implants after joint surgery. Magnesium, however, can achieve sufficient strength compared to current materials. In addition, since it is self-decomposed after the recovery, reoperation is not necessary. In this paper, Mg alloys were designed by adding harmless Ca and Zn to the human body. In order to improve the strength and corrosion resistance, the final alloy was designed by adding a small amount of Sr as a grain refiner. The radioactive elements of Sr are harmful to the human body, but other naturally occurring Sr elements are harmless. Microstructure analysis of the alloys was performed by optical microscopy and scanning electron microscopy. The mechanical properties and corrosion characteristics were evaluated by tensile test, potentiodynamic test and immersion test.

• Fashion & Textile Research Journal
• /
• v.20 no.5
• /
• pp.583-591
• /
• 2018

This study investigated the current production of women's sportswear tights among a total of 813 yoga, gym and training tights on the market to provide basic data for the development of women's sportswear tight tops. The results found the following: First, according to the analysis of women's sportswear tight tops by brand, polyester, nylon and polyurethane were most used. In addition, elastic, breathable and quick-dry, sweat absorbent products were commonly found. In terms of design, crew neck and sleeveless styles were popular. In addition, mesh was frequently applied to the top of the chest and upper part of the back. The size was mostly marked in S, M and L, and the size range was very large by brand. For color, achromatic color was most common. In terms of price, 'KRW 50,000-100,000' was frequently found. Second, yoga tights were compared to gym & training wear. In the case of yoga tights, elastic, various products in diverse design (e.g., crew neck, sleeveless, long sleeve, etc.) and colors (e.g., red, black, etc.) made of breathable and water-absorbing fabric were most produced. In particular, a combination of mesh materials was common. In gym and training wear, crew neck and short-sleeve styles in achromatic color made of elastic, breathable and quick-dry, seat absorbing fabric were most produced.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 1996.11a
• /
• pp.42-48
• /
• 1996

Glare phenomenon by sun's altitude and strong sunlight make a much visual handicap. And so, it reaches to unreadable situation although enough illumination in the fore site student of a window site and passage site. In school student seat arrange in the order of their height. So, cause the eyesight acuity according to distance is different, eyesight of backseat's student drop 1.0 and less in spite of 1.0, a learning effect reduces rather then that of the fore site student for site and Passage sitestudents. Therefore. in school, the conclusion's alteration of school structure, position's alteration and material quality's improvement of blackboard are needed, should be local lighting in blackboard. Therefore, we think that in other in improve the effect of lesson by the student, the student seats are not given by uniform disposition in the order of their height but change by a specified period.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.2
• /
• pp.373-380
• /
• 2020

A valve product can be over-designed or too heavy. Finite element analysis was performed using ANSYS for two and three-dimensional ball valve models, and the ball weight was reduced by optimization within the allowable design criteria. The ball is structurally safe according to the computed stress values, which are within the material's admissible stress. The weight was reduced by about 22%, and the structural safety factor was 1.25. The structural safety of the seat insert and ring, which are used to prevent leakage, was confirmed through finite element analysis. It is shown that the two-dimensional analysis can result in similar values to the three-dimensional analysis for the axisymmetric structure. The redesign of the valve is not included in the results since such changes require a whole new design process, including all valve components.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.6
• /
• pp.2581-2587
• /
• 2013

This paper aims at the design of wheel and axle with cap. The cap is conceptually designed by using TRIZ/CAE. Wheel axle is used at railway vehicle to safety and it is always investigated to reduce the railway vehicle weight. The cap has hollow shaft with the material of SM45C. Cap is located in the bearing seat of wheel and axle. The cap becomes durable within the allowable stress of EN13103, 13104 standard. In this study, the strength of wheel and axle with cap becomes higher than that of hollow shaft. The weight of wheel and axle with cap becomes lower by about 6.75 percent than that of solid shaft. The confidence of wheel and axle with cap can be improved by comparing with solid and hollow shafts.

• Journal of the Korean Society for Heat Treatment
• /
• v.13 no.4
• /
• pp.246-252
• /
• 2000

Stellite 12 alloy-powder was overlaid on 410 stainless steel valve seat using plasma transferred arc(PTA) process. Variation of characteristic of microstructure and hardness of deposit with current(90~150 A) and preheat temperature(R.T.~$400^{\circ}C$) was investigated. Important conclusion obtained are as follows; All welding conditions used produced a sound deposit layer with no defect in single pass welding. The maximum deposit had 4.0~4.8 mm in thickness and its bead width was increased with increase of current and preheat temperature. The deposit showed hypoeutectic microstruture, which was consisting of primary cobalt dendrite and networked $M_7C_3$ type eutectic carbides. The amount of eutectic carbides was decreased and its dendritic secondary arm spacing was increased with increase of current. Hardness of the deposit was decreased with increase of current. Preheat temperature up to $400^{\circ}C$, however, showed little influence on the hardness and microstructure. The hardness was also influenced by diluted Fe content near the interface in addition to microstructure and dendritic secondary arm spacing. Hot hardness at $500^{\circ}C$ showed higher than 300 HV.

• Journal of the Korean GEO-environmental Society
• /
• v.9 no.2
• /
• pp.47-59
• /
• 2008

Application of mechanically stabilized earth wall (MSEW) abutment has been rapidly increasing in United States of America, Pennsylvania since 2002. MSEW is effective for reducing construction cost and period compared to general concrete reinforced wall. In the paper, theoretical background and conventional criterion of MSEW abutment that is widely used abroad are analyzed. Based on the results, application of suitable MSEW abutment to domestic bridge type is examined. For the application of MSEW abutment in Korea, load interacting with upper shoe in domestic bridge types and structural analyses of beam seat and pile are investigated. As a result, all applications are possible except for PSC BOX Bridge that has heavy self-weight of girder. Through two and three dimensional numerical analyses, horizontal behaviour mechanisms between pile and MSEW were analyzed and field tests are also carried out for seven piles behind earth walls. From results of field tests, it is confirmed that an angle of internal friction of backfill material needs to be greater than 34 degree to use H-Pile as foundation of MSEW.

• Journal of the Korea Furniture Society
• /
• v.17 no.4
• /
• pp.1-13
• /
• 2006

This study attempted to identify the characteristics of chair design from furniture company, $K{\ddot{a}}llemo$, the furniture manufacturer in Sweden manufacturing mostly the limited edition of art furniture on the basis of the unique management philosophy. There are 12 artists manufactured chairs for $K{\ddot{a}}llemo$. Of them, this study selected 4 artists-Sigurdur Gustafsson, John Kandell, Komplot Design, Mats Theselius-who designed at least more than three chairs. Total 25 chairs were analyzed; 6 from Sigurdur Gustafsson, 8 from John Kandell, 3 from Komplot Design and 8 from Mats Theselius. The chair structure was divided into three parts, seat, back and structure and analyzed by material, color, type of legs and finishing. The following results were derived from the study. First, $K{\ddot{a}}llemo$ secured the regular customers who want to possess the chairs as the artistic works by continuing the small quantity mass-production system insisting that the maximum quantity of production is 360 pieces and the minimum quantity is 33 pieces. Second, the sufficient time and cost were invested in the initial phase of design. This approach seems to be deviated from the traditional business system that has to create the revenue at a glance, but ultimately induces the commercial success by exponentially increasing the revenue through the creation of various product lines. Third, $K{\ddot{a}}llemo$ provides the space that the artists who work for $K{\ddot{a}}llemo$ can sufficiently enjoy the mental composure and luxury required for the designers by strictly selecting the artists and providing the best environment for enabling the creative activities that look like the pure art area. This study enables the further analysis and research on other collections of $K{\ddot{a}}llemo$ that mass-produces the chairs on the basis of the unique philosophy in the world as well as in Sweden using more various kinds of analysis frameworks.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.18 no.10
• /
• pp.68-74
• /
• 2019

In the case of a partition panel for a vehicle, it is used as a vehicle chassis component that serves to distinguish the indoor and outdoor spaces of a vehicle and is mounted on a backrest portion of the vehicle's back seat to ensure the convenience of passengers by connecting the floor and the side of the vehicle. Because it is a relatively large-sized plate material among automobile chassis parts except the moving parts and non-ferrous materials can be applied, it is considered as a part having a large light-weight effect. However, the partition panel is one of the vehicle parts that must satisfy the light-weight effect as well as various structural reliability, such as torsional rigidity, vibration, and impact characteristics, for securing the running stability of the vehicle when driving at the same time. So, In this study, the possibility of replacing the aluminum partition panel as CFRP(Carbon Fiber Reinforced Plastic) partition panel is evaluated through comparing the two partition panels by using the structural reliability(stiffness/strength analysis), vibration analysis, impact analysis.