• Proceedings of the KSR Conference
• /
• 2001.10a
• /
• pp.273-278
• /
• 2001

The transmission system of high speed train serve in the severe condition compared with those of other trains, namely, they have to transmit high power to run with high speed and they have to make maximum use of the limited space. To clarify the strength of gear for Korea High-speed train, a bending fatigue test is performed for the output gear of axle gear reduction unit. This paper reports the reviews of bending fatigue strength test method and the test results of output gear of axle gear reduction unit for high speed train.

• Proceedings of the KSME Conference
• /
• 2008.11a
• /
• pp.1271-1276
• /
• 2008

This study has explained about LED for BLU which is widely used in the kinds of display devices or lighting. It was shown that the open due to delamination were the dominant LED for BLU failure mode and mechanisms from failure analysis of LED samples. Then, we have defined failure as yellowing and 100% reduction of light output intensity of LED for BLU and acceleration factors as temperature and current in Accelerated Life Test(ALT). Finally, we have estimated the Weibull distribution, life-stress relationship, and accelerating factor is used by ALTA Software.

• Advances in Traditional Medicine
• /
• v.7 no.3
• /
• pp.304-310
• /
• 2007

Monocrotophos was administered orally to adult male albino mice at dose level of 3.0 mg/kg body weight/day/mice for 50 days. The treatment has found to affect spermatogenesis as well as the endocrine functions of the testis as indicated by gravimetric, histopathological and biochemical changes. The treatment has caused degenerative changes in the seminiferous tubules and Leydig cells of the testis and regression of the epididymis, seminal vesicle, vas deferens, prostate, Cowper's gland and levator ani. Similarly, cauda epididymal sperm count and sperm motility have shown significant reduction. There was a significant reduction in the protein, glycogen, sialic acid, acid and alkaline phosphatase and increase in cholesterol in the testis of monocrotophos treated mice compared with the control. The causative factors for these changes due to monocrotophos administration were discussed.

• Transactions of Materials Processing
• /
• v.20 no.4
• /
• pp.284-290
• /
• 2011

The front end bending(FEB) behavior of material that usually occurs in plate rolling is investigated. In this paper, a rollbite profile map approach that systematically predicts the FEB slope is presented. It is based on the concurrent use of shape factors and reduction ratios to ensure an accurate value of the FEB and its slope. In order to obtain the unit roll-bite profile map, the FEB slope model was decomposed into a temperature deviation component and a roll-velocity deviation component. By mapping the results of a series of finite element analyses to the unit functions of the roll-bite profile map, it was possible to obtain a realistic prediction of the FEB slope applicable to an actual plate rolling process. Thereby, the usefulness of the present approach is clearly demonstrated.

• Proceedings of the KAIS Fall Conference
• /
• 2001.05a
• /
• pp.82-83
• /
• 2001

Selected microbes was applied to the treatment of textile wastewater with support particles. To enhance the treatment efficiency, biological treatment was achieved as first process. Wastewater with a COD of 870 ppm and color of 1340 PtCo unit was continuously treated in a 1.8 ton capacity reactor. In the case of combined processes, the effluent COD concentration and color were 40 ppm (95.4% reduction) and 20 PtCo unit (98.5% reduction).

• Journal of Korea Society of Industrial Information Systems
• /
• v.23 no.3
• /
• pp.131-142
• /
• 2018

Since income growth rate and poverty level are related, there is a possibility that the poverty rate may converge in the long run steady state as well. If the poverty rate converges, then for this study the state that begins with the high poverty rate would have a higher poverty reduction rate. To examine the convergence of poverty rate among the US states, this study uses two times series methodologies. First, in order to prevent the power loss from ignoring the structural break when testing for a unit root in a single time series, this study employs the newly developed panel LM unit root tests with level and trend shifts. The results of unit root tests of the log of poverty rate without allowing for structural breaks show that twenty six states reject the null hypothesis of unit root test for the ADF test, twenty five states for the LM test, and thirty five states for the RALS-LM test. The result of unit root tests that allow one structural break shows that the null hypothesis of a unit root test is rejected for twenty two states with the LM test, and thirty three states with the RALS-LM test. This supports poverty rates are converging among US states.

• Proceedings of the KIPE Conference
• /
• 1998.10a
• /
• pp.950-954
• /
• 1998

This paper describes a development of traction unit for 2-motor driven electric vehicle (EV). The traction unit is consisted with an interior permanent magnet synchronous motor (IPMSM), a reduction gear and an inverter for electric vehicle that is driven by 2 motors without differential gear. For traction unit, prototype IPMSM and inverter have been developed. The IPMSM was designed by CAD program that was developed with both equivalent circuit method and FEM. Also the inverter was developed to drive 2 motors with 6 legs IGBT switches in a control board. The vector control algorithm was implemented with maximum torque control method in the constant torque region and field weakening control method in the constant power region considering inverter capacity. To verify that the traction unit is more high efficiency and has more high power density than a traction unit with induction motor with the same power, we would like to show the results about the design and analysis of the IPMSM and the experiment results about the traction unit.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.852-855
• /
• 2003

Gas-Assisted Injection Molding(GAIM) process, that can be used to provide a hollow shape in a molding, is a variant of the conventional injection molding process. GAIM has many advantages such as reduction of material, sink mark. warpage. and lower injection pressure. Thus, GAIM has been widely applied in the industry to make moldings with a hollow channel such as handles, TV frames and so on. On the other hand, GAIM has some disadvantages such as slow cooling time and flow marks. In the disadvantages, hot gas core causes slow cooling of a molding and the overflow. which is to prevent flow mark. is waste of materials. To solve these problems, we developed a new GAIM system that we called RGIM(Reverse Gas Injection Molding). The RGIM has two special units; one is the overflow buffer, which is used for reduction of a material, and the other tile air unit, which is used for faster cooling of a molding. We conducted an experiment and simulation to verify the efficiency of the RGIM system. Through experiments and simulation, we confirmed the effectively operating of the RGIM system and extracted the optimum process conditions.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2012.05a
• /
• pp.215-216
• /
• 2012

Emissions of CO₂ occur during the production of cement manufacturing process. During the production of clinker, limestone is mainly calcium carbonate, is heated to produce lime and CO₂ as a by-product. It has a major problem, CO₂ uptake is not considered in concrete carbonation, just focus in CO₂ emission. This study is to develop a simulation model for CO₂ uptakes in concrete structures based on carbonation reduction coefficient considering finishing materials. CO₂ uptakes unit of concrete cubic meter is calculated by CO₂ emissions unit of concrete materials and usage of concrete materials in mix proportion. From the simulation result, CO₂ uptake ratios is 2.04 percent in carbonation models of concrete structure during 40 years.

• Archives of Plastic Surgery
• /
• v.42 no.3
• /
• pp.302-308
• /
• 2015

Background In the literature on nipple-sparing mastectomy (NSM) with one-stage immediate implant reconstruction, contralateral symmetrisation has drawn little attention, with many surgeons still performing standard cosmetic mammaplasty procedures. However, standard implant-based mammaplasty usually does not result in proper symmetry with the mastectomy side, especially regarding breast projection, overall shape, and volume distribution. Methods We retrospectively reviewed 19 consecutive patients undergoing unilateral NSM with immediate prosthetic reconstruction and contralateral simultaneous symmetrisation by using the tailored reduction/augmentation mammaplasty technique between June 2012 and August 2013. Results The average follow-up time was 13 months (range, 10-24 months). No major complications, such as infection, haematoma, and nipple-areola complex necrosis, were experienced. Conclusions Our experience suggests that simultaneous contralateral symmetrisation with tailored reduction/augmentation mammaplasty after unilateral immediate implant reconstruction after NSM facilitates durable and pleasant symmetric outcomes.