• Textile Coloration and Finishing
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• v.35 no.1
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• pp.29-41
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• 2023

This study is about a hybrid lightweight cowl crossbeam structure with high rigidity and ability to absorb collision energy to support the cockpit module, which is an automobile interior part, and to absorb energy during a collision. It is a manufacturing process in which composite material bracket parts are inserted and injected into existing steel bars. When considering the mounting condition of a vehicle, the optimization of the fastening condition of the two parts and the mechanical properties of the composite material is acting as an important factor. Therefore, this study is about a composite material having a volume content of Polyamide(PA) and Glass Fiber used as a composite material for a composite material-metal hybrid cowl crossbeam. As a result of analyzing the physical properties of the PA/GF composite material, experimental data were obtained that can further enhance tensile strength and flexural strength by using PA66 rather than PA6 used as a base material for the composite material. And based on this, it contributed to securing the advantage of lightening by using high-stiffness composite material by improving the high disadvantage of the weight of the cowl crossbeam material, which was made only of existing metal materials.

• Journal of the Earthquake Engineering Society of Korea
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• v.1 no.2
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• pp.39-48
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• 1997

New form of base isolators made of steel spring coated with both natural and artficial rubber were manufactured and tested for material properties. Shaking table experiments were performed using a model structure attached with the bearings. The model structure used in the test is a 1/4 scaled steel structure, and earthquake records were used to check the lateral and vertical stability and effectiveness of the isolators. According to the results all three types of isolators turned out to be effective in reducing the acceleration induced by the earthquake vibration.

• Journal of Welding and Joining
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• v.4 no.3
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• pp.32-42
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• 1986

In this study, the influence of carbon equivalents on friction welds of dissimilar steels was investigated. Four types of carbon steels with 10mm diameter were welded to a high-speed tool steel SKH 9. Main experimental results could be summarized as follows (1) Under constant friction pressure, the friction time increased almost linearly with the increasing burn-off length, while the forge length decreased almost linearly. (2) The maximum hardness in carbon steels increased almost linearly with the increasing carbon equivalent, but was much lower than that in the high speed steel. (3) After quenching and tempering of dissimilar steel friction welds, the hardness in carbon steel weldments became similar as that in the base metal, while the hardness in SKH 9 weld was still higher that of the base metal. (4) Relative movement in the friction phae occurred not at the interface of the weldments, but in the high speed steed steel near the interface. (5) For considered material combinations and welding parameters, most of fractures in tension and twisting tests occurred in the base metal. And welds with so high strength could produced in a wide range of welding parameters.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.970-974
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• 1993

This paper is concerned with an automatic generation of BOM (Bill Of Material) for a bicycle frame set using a knowledge based system. The major components module system includes : (1) Part information retrieval in CAD drawing, (2) BOM code generation rule, and (3) Database interface. The knowledge based system includes a rule base and a fact base. The fact base consists of basic, variant, and optional components of the standard BOMs of frame sets. The rule contains rules for generating new BOM code in case that the specified is not in the database. The system was implemented on a SUN workstation under Open Windows environments. AutoCAD for CAD drawing was also used.

• Wind and Structures
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• v.7 no.3
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• pp.203-214
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• 2004

This paper describes a method for developing a multi-degree-of freedom aero-elasto-plastic model of a base-isolated mid-rise building. The horizontal stiffness of isolators is modeled by several tension springs and the vertical support is performed by air pressure from a compressor. A lead damper and a steel damper are modeled by a U-shaped lead line and an aluminum line. With this model, the frequency ratio of torsional vibration to sway vibration, and plastic displacements of isolation materials can be changed easily when needed. The results of isolation material tests and free vibration tests show that this model provides the object performance. The peak displacement factors are about 4.5 regardless of wind speed in wind tunnel tests, but their gust response factor decreases with increment of wind speed.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.637-640
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• 2006

DuPont Teijin Films (DTF) have developed engineered substrates specifically for the flexible electronics market. $Teonex^{(R)}Q65$ is a biaxially oriented crystalline polyester with a tailored surface and it is emerging as a competitive material for the base substrate in OLED displays and active matrix backplanes. Given the dimensional reproducibility requirements in the display applications, uncontrolled moisture absorption during the processing cycle could potentially be far more significant than the inherent shrinkage of the base substrate. Understanding these effects and optimising the processing steps involved in device manufacture will be critical to achieving the ultimate performance that can be achieved with the base substrate.

• Transactions on Electrical and Electronic Materials
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• v.8 no.3
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• pp.115-120
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• 2007

Reliability between passivated and unpassivated process with the base-exposed InGaP/GaAs HBTs was studied. A passivation of HBT was attempted by $SiO_2$ thin film deposition at $300^{\circ}C$ by means of PECVD. Base-exposed InGaP/GaAs HBTs before and after passivation were investigated and compared in terms of DC and RF performance. Over a total period of 30 days, passivated HBTs show only 2% degradation of DC current gain for the high current density of $40KA/cm^2$. The measured thermal resistance of $2{\times}30{\mu}m^2$ single emitter InGaP/GaAs HBT passivated with PECVD $SiO_2$ devices can be extracted and was founded to be 1430 K/W. The estimated MTTF was $2{\times}10^7hr\;at\;T_j=125^{\circ}C$ with an activation energy $(E_a)$ of 1.37 eV.

• Earthquakes and Structures
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• v.3 no.6
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• pp.853-867
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• 2012

In this paper, a new type of passive energy dissipating system similar to added damping and stiffness (ADAS) and triangular added damping and stiffness (TADAS) is proposed and implemented in the analytical model of a building with hybrid structural system in the structure's base which we call it; Telescopic column. The behavior and performance of a high rise R.C. structure equipped with this system is investigated and compared with conventional base isolation systems such as rubber isolator bearings and friction pendulum bearings. For this purpose a series of ground acceleration records of the San Fernando, Long Beach and Imperial Valley earthquakes are used as the disturbing ground motions in a series of numerical simulations. The nonlinear numerical modeling which includes both material and geometric nonlinearities were carried out by using SAP2000 program. Results show suitable behavior of structures equipped with telescopic columns in controlling the upper stories drifts and accelerations.

• Journal of Welding and Joining
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• v.19 no.6
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• pp.608-613
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• 2001

In this study, the rotary bending fatigue test was carried out with two kinds of base metal, martensite stainless steel STR3 and austenite stainless steel STR35 and the dissimilar friction welded material with them. To compare the fatigue fifes according to the notch positions, the small circular defect was worked on the bonded line, 1.0mm and 0.5mm distance form the bonded line. The fatigue limits of the STR3 and STR35 base metal were 429.0MPa and 409.4MPa respectably. In comparison with fatigue life at the same notch positions, the STR35 specimens showed about 190% for base metal, 82% for 1.0mm distance notched specimens higher than that of the STR3. But the fatigue life of the 0.5mm distance notched STR35 specimen showed about 35% lower than that of the STR3 specimen. And the bonded line notched specimen was much lower fatigue life than the other specimens because of separation of the bonded line.

• Journal of Biosystems Engineering
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• v.21 no.2
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• pp.182-190
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• 1996

A macerating technique which can apply to the mechanical production system of the agricultural by-product was developed to increase the utilization of agricultural waste and solve the shortage problem in the forage supply for the livestock production. The macerating method is to shred the agricultural by-product by the two rolls which rotate at different speeds each other. The testing macerator was built and the optimum operating conditions are suggested. Results of this research are as follows: 1. The increase of the base roll speed and speed ratio between two rolls shows the better shredding index but decrease the drying rate. The optimum conditions of the base roll speed and the speed ratio between two rolls for the rice straw are 1200 rpm and 1.7-2.0 respectively. 2. The macerated alfalfa was dried to the 15%(w.b.) within 3 hrs in a field at speed ratio of rolls, 2:1 and base roll speed, 1800rpm. 3. The milled surface and straight knurled surface for the macerating roll have same effect on the drying rate of material. Both rolls have self-cleaning functions during operation.