• Journal of Ship and Ocean Technology
• /
• v.9 no.2
• /
• pp.11-20
• /
• 2005

A mixed-flow pump is largely applied for waterjet propulsion in high-speed vessels because of excellent cavitation performance. For the present study, we analyze the performance of mixed-flow pump, which is composed of impeller and stator. The test device for a mixed-flow pump was installed in the test section in the KRISO cavitation tunnel. The performance tests of two mixed-flow pumps were carried out with the test device at various flow rates using various nozzles. The test results agree fairly well with the predicted results by commercial CFD code. The test device is available for verification of impeller performance together with CFD analysis

• Journal of the Korea Institute of Military Science and Technology
• /
• v.26 no.3
• /
• pp.273-280
• /
• 2023

Recently electronic safety and arming device(ESAD) has attracted increasing attention due to its design flexibility. However, ESAD can be armed unintentionally due to a malfunction of an external device or interface. Thus ESAD needs an internally generated arming signal independent from the external device. In this paper, a new sensor-hybrid ESAD(SHESAD) with a flight environment sensing function for generating arming signal internally is proposed and a sled test based method is also suggested for evaluating its functions. Through the test results, the operability of the flight environment sensing function was confirmed. Also, it is shown that the proposed test method is suitable for verification of ESAD with the flight environment sensing function.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2003.05a
• /
• pp.236-239
• /
• 2003

The spent fuel slitting device is an equipment developed in order to feed UO$_2$pellet to the dry pulverizing/mixing device. In this study, we have compared and analyzed the handling method of the slitting and that of the pellet and hull, processing time, separating time for 20kgHM, the number of blades, on the existing slitting device using in DUPIC, and spent fuel management technology research and test facility. Also, we have compared and analyzed about an advantage and weak point, designing and producing, processing, establishment, operation, maintenance about the vertical and horizontal slitting device. Based on these results, we have developed the vertical slitting device. By using the results, we have enhanced the slitting processing time(over 40%)in comparison with DUPIC device, and it will is effectively applied to available data for designing and producing of the hot test facility.

• The Journal of Information Technology
• /
• v.2 no.2
• /
• pp.235-250
• /
• 1999

The test of digital VLSI devices is to insure that the device will perform all of its designed functions while in the worst-case environments. According to increasing the integration of the communication device, there are important consideration about the improvement of the reliability in the product. To improve the reliability of the device, the test parameters and test time are increased. There are basically three kinds of tests: functional, DC parametric, and AC parametric. There are no pin-to-pin short test and pin-to-pin leakage test in the present test items to analysis the characteristics and reliability of the device. The purpose of the paper is to model the pin-to-pin phenomenon and propose to modify the test method and to test the new pin-to-pin DC parameters. These modified and additive test items were applied to product test and confirmed to improve the reliability of product test.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.43 no.7
• /
• pp.635-640
• /
• 2015

In this paper, we report a non-explosive separation device for a small satellite which utilize a shape memory alloy actuator. Based on previous research, we try to increase the reliability of the proposed device by changing some components. It enables the proposed device to activate under high preload. Also, we confirm it generates low shock which is main advantage of non-explosive separation device. Finally, vibration test which mimics launching environment and thermal vacuum test which mimics space environment are carried out respectively. After each environment test, we confirm the proposed device is successfully activated. Conclusively, we develop a non-explosive separation device which can activate with low shock under high preload after shock and environment tests(vibration and thermal vacuum tests).

• Journal of the Korean Society for Railway
• /
• v.12 no.5
• /
• pp.663-669
• /
• 2009

In the electrical railway, the increase of tensions in an overhead contact lines is essential to speed-up of train, because current collection quality largely depends on the ratio of a wave propagation speed to a train speed. For Kyungbu high-speed line, a pulley-type tensioning device is required to have a tension variation of maximum 3%. Therefore we developed a pulley-type tensioning device in order to meet tension variation requirement of the high-speed tensioning device. To verify the performance of the developed device, a performance test, overload test and failure test were carried out according to the factory test procedure of the Kyung-Bu High-speed line. Furthermore, we also performed reliability performance through not only a fatigue test in a factory, but also on-line verification test in Chungbuk line for over 1 year. These tests verified that the tensioning device had applicability to a main line.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2011.11a
• /
• pp.548-553
• /
• 2011

The device for studying combustion characteristic of aluminum powder and water was developed. The device has ability to adjust temperature, pressure, and equivalent ratio to some specified value which effect on combustion characteristic of aluminum and water mixture. Methane combustor, water supply device, aluminum powder feeder, and linear combustor are assembled to aluminum combustion test device. Each device has the ability to supply matter to combustor on steady and quantitatively controlled manner and test sequence specified by user can be automatically controlled. The combustion of aluminum powder was observed when integrated device was operated normally.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.25 no.10
• /
• pp.102-108
• /
• 2011

The existing power flow has a single direction to the line end but the bidirectional power flow will possibly occur depending on the output capacity in the 22.9[kV] distribution power system connected with the dispersed generation(DG). So these characteristics would influence the power system management. The DG have many advantages such as assistance source, Load share etc. So the utility must apply the bidirectional protection system so as to maximize an advantage of DG. This paper describes the field test case of bidirectional protective device in order to investigate the device performance when applied to bidirectional power system. We have tested in the power system test site of KEPCO and these tests provide the basis for performance verification test of bidirectional protective device in the power system.

• Proceedings of the KIEE Conference
• /
• 2001.07d
• /
• pp.2193-2195
• /
• 2001

This paper proposes test strategy detecting the faulted digital device or the faulted digital circuit on the digital circuit board using signature analysis technique based on the polynoimal division theory. SSA(serial Signature Analysis) identifies the faults by comparing the reminder from good device and reminder from the tested device, which reminder is obtained by enforcing the data stream outputed from output pins of tested device on LFSR(Linear Feedback Shift Resister) representing the characteristic equation.

• Journal of Applied Reliability
• /
• v.14 no.3
• /
• pp.162-168
• /
• 2014

This paper discusses the application of Bayesian techniques with test data on similar products for performing the Economical Reliability Test of new one-shot device. Using the test data on similar products, reliability test required lower sample size currently being spent in order to demonstrate a target reliability with a specified confidence level. Furthermore, lower sample size reduces cost, time and various resources on reliability test. In this paper, we use similarity as calculating weight of similar products and analyze similarity between new and similar product for comparison of the essential function.