• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2002.10a
• /
• pp.170-173
• /
• 2002

The object of this study is to investigate the effect of compounded welding through the AE (Acoustic Emission) characteristics on static tensile test. This study was carried out a SM 490A, high tension steel using the low hydrogen type E4316 of electronic shield metal arc welding and compound wire of $CO_2$gas arc welding. $CO_2$welding, weak in the intensity of HAZ (Heat Affected Zone), can be improved by being combined with coated arc welding, Coated arc welding, weak in the intensity of the bead, can be improved by being combined with $CO_2$welding. Especially, electronic coated arc welding and $CO_2$welding complement the mechanical intensity of HAZ and the bead with each other. So, compounded welding increases the intensity in the special parts and enhances the quality of goods.

• Korean Journal of Pharmacognosy
• /
• v.20 no.3
• /
• pp.149-153
• /
• 1989

The presence of saponin, terpenoid, steroid, anthraquinone and flavonoid were screened with the usual test methods in forty five(sixty four parts) Korean plants belonging to Urticaceae, Celastraceae, Rhamnaceae, Sterculiceae and Rubiaceae. Plants were extracted with methanol and fractionated with hexane, chloroform, ethyl acetate and butanol. Each fraction was tested for the components. The result showed that in saponin test, 21 plants were positive and 11 plants were weak positive; in terpenoid and steroid test, 26 plants were strong positive; in anthraquinone test, 20 plants strong positive; in flavonoid test, 31 plants were positive and 9 plants were weak positive.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.20 no.5
• /
• pp.523-527
• /
• 2011

Polycarbonate (PC) polymer is an engineering plastic which has large tensile strength and impact resistance and is wildly used as functional parts like micro mold. Direct machining of PC materials produces lots of burrs and rough surface due to large ductility and weak heat resistance and hence it is very difficult to machine PC materials using cutting tool to make micro-parts. In this study, elliptical vibration cutting (EVC) or 2-dimensional vibration cutting was performed to minimize the size of micro V-grooves on PC material. From the experimental results, it was observed that as the cutting depth and pattern size become smaller, the better machining quality was obtained, which is attributed to the positive effect of EVC that is dependent on the ratio of vibration amplitude to cutting depth. As the height of V-groove becomes less than $1.8{\mu}m$, however, the machining quality becomes lower as the pattern size decreases.

• Journal of Auto-vehicle Safety Association
• /
• v.10 no.3
• /
• pp.13-19
• /
• 2018

This research is to optimize Single-Piece Side otr reinforcement using Hot-stamping and to strengthen weak regions on Single-Piece Side otr reinforcement. As a consequence, the weight and the number of parts were reduced and resulting in improvement of impact and stiffness performance when compared to multi-piece construction.

• Applied Biological Chemistry
• /
• v.2
• /
• pp.15-16
• /
• 1961

Distribution of $P^{32}$ in a pot-grown plant of the radish was studied by means of fertilization with phospbate labeled with $P^{32}$ followed by autoradiography of the dried parts. (1) An accumulation of $P^{32}$ occurs in the growth point, the root of hair, the younger leaves and the top of leaves in the radish similary other plants. (2) In the yellow leaves of the radish it was counted too weak by monitor. (3) $P^{32}$ absorbed by the root in radish was transported through the xylem of the radishtissue.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 1996.10a
• /
• pp.176-182
• /
• 1996

This paper describes an empherical equation which is to predict the engine condition of the supersonic aircraft. The equation, which is a function of running time of engine and engine oil, is derived from the trend analysis of JOAP data. Qualitative analysis is carried out to make up for the weak points in the current JOAP system. Also wear debris collected from the abnormal engine is analyzed by EDS to detect the damaged parts of engine.

• Special Issue of the Society of Naval Architects of Korea
• /
• 2009.09a
• /
• pp.93-96
• /
• 2009

Foundation structure for the main engine heavy spare parts in the engine room is susceptible to resonance problem due to outfitting weight. In addition the deck floor has a large opening for the main engine installation and maintenance, which further weakens the foundation structure. To reinforce the weak structure, two types of approaches have been used; 1) insert an H-pillar below or above the floor and 2) increase the stiffener size. In this paper, the H-pillar approach is used to solve the vibration problem of the foundation structure in the engine room opening area. A commercial program is used to analyze the vibration problem ad to find the location and the size of the H-pillar. Modal test at the quay and on-board vibration measurement during the sea trial have confirmed the validity of inserting an H-pillar below the floor.

• Journal of the Korean Society for Precision Engineering
• /
• v.15 no.3
• /
• pp.31-37
• /
• 1998

The structure of satellite consists of six parts which are control system, power system, thermal control system, remote measurement command system, propellant system and thrust system. In these parts, propellant system consists of propellant tank and thrust device. What we want to perform is optimum design to minimize the weight of propellant tank. In order to design optimal propellant tank, several parameters should be adopted from the tank geometry like the relative location of the lug and variation of the wall thickness. The analysis was executed by finite element analysis for finding optimal design parameters. The structure was divided into three parts consisting of the initial thickness zone, the transitional Bone, and the weak zone, whose effects on the pressure vessel strength was investigated. Finally the optimal lug location and the three zone thickness were obtained and the weight was compared with the uniform thickness vessel.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.2
• /
• pp.617-622
• /
• 2011

In this paper, the structural analysis is carried out with the vertical loading condition on the platform of the high place working vehicle. The model of analysis is reduced on the scale of 1:10. Deformation and stress distribution of boom are analyzed with the variation of angle at boom position and the vulnerable parts are checked. Analysis result shows that most stress is concentrated at the connection of the boom. Through this analysis result, the safety on this vehicle can be improved by making up for the relatively weak connection parts as compared with other parts.

• Journal of the Korean GEO-environmental Society
• /
• v.20 no.10
• /
• pp.5-14
• /
• 2019

Recently, earthquakes have occurred in our country and seismic stability of high-rise buildings in large cities is being a growing interest and thus the related studies have been increased. Also the grounds are considered indirectly in most of seismic designs and analyses and seismic researches based on 3D dynamic analysis are insufficient. In this study, therefore, 2D and 3D dynamic analyses were performed based on the SSI complete model including grounds and the behavior was compared and analyzed. For dynamic modeling, linear time history analyses were performed by using MIDAS GTS NX. For this purpose, a high-rise building was assumed to be constructed on top of the bedrock and surrounded by a surface layer. A sensitivity analysis was performed with the selected parameters. The dynamic behavior was compared and analyzed in terms of horizontal displacements, drift ratios, bending stresses, and weak parts. In most cases, 2D dynamic behavior was calculated to be larger than 3D's and thus it shows more conservative results with increasing number and size of weak parts.