• Proceedings of the SAREK Conference
• /
• 2008.11a
• /
• pp.33-38
• /
• 2008

A ground-loop heat exchanger in a ground source heat pump system is an important unit that determines the thermal performance of a system and its initial cost. The Size and performance of this heat exchanger is highly dependent on ground thermal properties. A proper design requires certain site-specific parameters, most importantly the ground effective thermal conductivity, the borehole thermal resistance and the undisturbed ground temperature. This study was performed to investigate the effect of some parameters such as borehole lengths, various grouting materials and U-tube configurations on ground effective thermal conductivity. In this study, thermal response tests were conducted using a testing device with 9-different ground-loop heat exchangers. From the experimental results, the length of ground-loop heat exchanger affects to the effective thermal conductivity. Among the various grouting materials, the bentonite-based grout with silica sand shows the largest thermal conductivity value.

• Proceedings of the KSR Conference
• /
• 2002.10a
• /
• pp.131-136
• /
• 2002

Performance test is carried out in accordance with "performance test standard for Electrical Multiple Unit", noticed by Ministry of Construction ＆ Transportation in 2000. The object of this standard is to ensure that vehicle is tested after completion and before entry into service. Performance test is classified by type test to be carried out for the first car and its components in order to verify their performance and by routine test to be carried out on the whole quantity in order to prove the performance of individual items. Scope of the test is divided by components, completed car, preliminary adjustment test and running test on main line. The paper introduces a testing procedure and an execution method of the performance test.

• Journal of the Korean Data and Information Science Society
• /
• v.17 no.3
• /
• pp.945-952
• /
• 2006

Several accelerated life test plans use tests at only two levels of stress and thus, have practical limitations. They highly depend upon the assumption of a linear relationship between stress and time-to-failure and use only two extreme stresses that can cause irrelevant failure modes. Thus 3-level stress plans are preferable. When the lifetime distribution of test unit is exponential with mean lifetime $\theta_i$ at stress $x_i$, i=0, 1, 2, 3, we derive the optimum quadratic plan under the assumption that a quadratic relationship exists between stress and log(mean lifetime), and propose the compound linear plans, as an alternative to the optimum quadratic plan. The proposed compound linear plan is better than two other compromise plans for constant stress testing and nearly as good as the optimum quadratic plan, and has the advantage of simplicity.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.12 no.1
• /
• pp.162-167
• /
• 2004

In this research the Co-simulation technique for an electric power steering system with MATLAB/SIMULINK and a full vehicle model with ADAMS has been developed. The dynamic responses of vehicle chassis and steering system are evaluated. Then, a full vehicle model interacted with EPS control is concurrently simulated with an impulsive steering wheel torque input to analyze the stability of 'free control' or hands free motion for Sports Utility Vehicle. This integrated method allows engineers to reduce the prototype testing cost and to shorten the developing period.

• Journal of Korean Institute of Industrial Engineers
• /
• v.25 no.4
• /
• pp.517-526
• /
• 1999

This paper deals with two economic optimal designs of constant-stress accelerated life test(ALT) where failure distribution follows one of location-scale family, i. e., exponential, Weibull, and lognormal distributions which have been ones of the popular choices of failure distributions. Two optimization criteria to develop ALT plans are the statistical efficiency per unit expected cost which consists of the fixed test cost, cost being proportional to the number of test units, and variable test cost depending on test period and stress level, and the expected loss which combines Taguchi's quadratic loss function and expected test cost. Optimum plan determines the low stress level, test units allocated to each stress, and censoring times at two stress levels under Type I censoring. The proposed ALT plans are illustrated with a numerical example and sensitivity analyses are conducted to study effects of pre-estimates of design parameters.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.27 no.3
• /
• pp.95-99
• /
• 2013

The maximum power analysis simulator took advantage of the facilities and power consumption reduction simulator test scenario development and testing of improvement in the scenario. As a maximum demand power controller, Maximum power analysis simulator performs control and disperasion of maximum demand power by calculating base power, load forecast, and present power which are based on signal of watt-hour meter to keep the electricity under the target. In addition, various algorithms to select appropriate control methode on each of the light installations through the peak demand power is configured to management. The simulation shows the success of control power for the specified target controlled by five sequential lighting installations.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.2 no.2
• /
• pp.140-147
• /
• 1999

A gene expressing organophosphorus acid (OPA) anhydrolases have been cloned from Alteromonas haloplanktis strain and expressed in bacterial strain BL21. Crude extract was prepared from the transformed bacterial strain BL2l and used in testing its degrading capability of real nerve gas, soman and sarin. Within 1 minute after the start of the reaction, nearly 65% of the soman added to the reactant(3mM) was degraded by adding 1 mg of the crude extract enzyme(20.0 Unit $mg^-{1}$ crude protein). In 6 minutes, the reaction reached at its steady state, which indicates that soman was completely degraded by that time. In the case of sarin, the degradation efficiency was observed to be about 0.7 times of that of soman. If the specific activity of OPAA is enhanced by both increased expression efficiency and purification, OPAA seems to be applied for the development of decontaminant of skin, especially of eye.

• Journal of the Korean Institute of Navigation
• /
• v.16 no.1
• /
• pp.1-12
• /
• 1992

In this study, the self test-system for the marine Gyrocompass was developed and the obtained results are summarized as follows : 1) Utilizing the newly developed self-test system, the time length for observing the transient state of Gyrocompass reading which has been over 4 hours can be reduced to less than 20 minutes. In addition, the dynamic characteristics of the Gyrocompass can be measured within 2 hours after starting the system. 2) Prior test and diagnosis was done by checking all parameters recurrently with period of 2.5minutes. 3) Testing and diagnosis results was shown in graphic mode and could be transmitted to INMARSAT unit using personal computer. 4) The results of the newly designed trouble algorithm for the system was found to be applicable under arbitrary given conditions.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.523-524
• /
• 2007

현재까지 변전소에 구축되어있는 변전소 자동화 시스템은 기존 설비를 바탕으로 지능형 장비(IED)를 추가한, 전력설비 자체의 인텔리전트화가 아닌 2차 설비(제어, 보호, 감시 장치)의 인텔리전트화를 지향하고 있었다. 그러나 본 실증변전소는 CT, PT와 같은 1차 설비에서부터 상위 시스템까지 전체 전력실비를 Intelligent화하였으며, Hardwiring되어 있는 시스템을 모두 통신과 S/W로 처리하였으며, 국내 최초로 Merging Unit을 개발, 적용하여 디지털 계전기를 검증하였다. 또한 향상된 예방진단 시스템 및 보안방재 시스템을 도입하여 변전소종합자동화 시스템을 구축하였다.

• Korean Journal of Microbiology
• /
• v.29 no.4
• /
• pp.215-220
• /
• 1991

MudJ(Km.lac) operon fusions were used in the identification of osmotic-inducible genetic(osi) loci in Salmonella typhimurium. Expression of osi::lacZ(osi5001, 5027) genes were dramatically induced 39-189 fold when the osmolarity was increased. Seven osm::lacZ genes were constituvely expressed under both low and high osmotic strength. The osi5001::lacZ fusion strains showed the enhanced osmotolerance and the reduced expression of the osi5001::lacZ in the presence of 1mM proline or betaine as osmoprotectants. Four osmotic inducible genetic loci were mapped into 36 (YK531), 44 (YK504), 57 (YK501) and 84 (YK528) map unit by testing the cotransduction frequency.