• Communications of the Korean Mathematical Society
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• v.20 no.1
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• pp.145-159
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• 2005

In this paper we consider the problem of testing statistical hypotheses for unknown parameters in nonlinear regression models and propose three asymptotically equivalent tests based on regression quantiles estimators, which are Wald test, Lagrange Multiplier test and Likelihood Ratio test. We also derive the asymptotic distributions of the three test statistics both under the null hypotheses and under a sequence of local alternatives and verify that the asymptotic relative efficiency of the proposed test statistics with classical test based on least squares depends on the error distributions of the regression models. We give some examples to illustrate that the test based on the regression quantiles estimators performs better than the test based on the least squares estimators of the least absolute deviation estimators when the disturbance has asymmetric and heavy-tailed distribution.

• Communications for Statistical Applications and Methods
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• v.4 no.1
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• pp.139-149
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• 1997

For split plot designs exact univariate F tests of the within-subjects main effect are based on the assumption of multisample sphericity. Type I error rates and power are reported for the F test and two tests designed for use when multisample sphericity is violated: the $\widetilde{\xi}$-adjusted test and the Corrected Improved General Approximation(CIGA) test.The results indicate that even though the F test and the $\widetilde{\xi}$-adjusted test have better power than the CIGA test in some conditions, the F test and the $\widetilde{\xi}$-adjusted test do not control Type I error rates when the design is unbalanced and the F test dose not have a good control of Type I error rates when sphericity assumption is severely violated.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.6
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• pp.804-809
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• 2007

In order to provide reliability. reproducibility. objectivity of solid particle separation performance test on marine centrifugal purifier, an investigation had been done on solid test dusts. test standards and designation of a definite standard test dust In test specifications or standards. ISO 121031-1 A2 test dust is the best test particle to meet commercial and military fuel oil and lube oil requirements on marine standards.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1231-1234
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• 2003

Pneumatic servo valve which is widely applied in industrial world is advanced technology compounded with electric, electronic and machine. And It is consist of Linear Force Motor. Spool Commutation Mechanism and Microprocessor. In this study, we accomplished test method of Linear Force motor test, Static characteristic test, Dynamic characteristic test for KS(Koran industrial standard) of Pneumatic servo valve. we accomplished study about the main item of Static characteristic test which is related to unload flow characteristic test. And Dynamic characteristic test was step input test and frequency response test. Specially about frequency response test, There was a difficulty resulting from the time delay problem caused by the basic compressibility of air. In order to solve the problem in this study. we proposed two methods. First, displacement of the servo valve spool was directly measured by using a laser sensor. Second, method of calculating control flow by measuring pressure and temperature of chamber.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11b
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• pp.41-44
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• 2005

This paper described improvement and operation of a 'Tail-Fan' anti-torque performance test system KARI (Korea Aerospace Research Institute) developed a 'Tail-Fan' anti-torque system of a helicopter and a performance test-rig to test the performance of the Tail-Fan. The test-rig was improved for full rotating test in 4300rpm(100%). Machinery and hydraulic parts ware changed to reduce vibration and to increase safety. To find the operation rotating speed for the performance test, vibration test were carried out rising accelerometers on tail gear box. The performance test conditions of the Tail-Fan to avoid a resonance were found from vibration test results. The Tail-Fan operation tests were performed safely frier to carry out performance test.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.9
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• pp.1-9
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• 1994

This paper analyzes the faults and their mechanism of CMOS ICs using IDDQ testing technique and evalutes the reliability of the chips that fail this test. It is implemented by the three testing phases, initial test, burn-in and life test. Each testing phase includes the parametric test, functional test, IDDQ test and propagation delay test. It is shown that the short faults such as gate-oxide short, bridging can be only detected by IDDQ testing technique and the number of test patterns for this test technique is very few. After first burn-in, the IDDQ of some test chips is decreased, which is increased in conventional studies and in subsequent burn-in, the IDDQ of all test chips is stabilized. It is verified that the resistive short faults exist in the test chips and it is deteriorated with time and causes the logic fault. Also, the new testing technique which can easily detect the rsistive short fault is proposed.

• Journal of Korean Society for Quality Management
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• v.34 no.1
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• pp.20-26
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• 2006

In the fields of mechanical reliability application, "zero" or "zero or one" failure tests are most commonly used for demonstrating reliability of a product since they reduce test duration and/or sample size compared to other test methods that guarantees the same reliability of a product with a given confidence level or consumer's risk. The test duration of the "zero or one" failure test is longer than that of "zero" failure test but it has advantage of smaller producer's risk. In this paper a two-stage test is developed that compromises the "zero" and "zero or one" failure tests. The properties of the proposed two-stage test are investigated and the three test methods are compared using a numerical example.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.175-182
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• 2001

The PMT test results are compared with other in situ test such as Standard Penetration Test (SPT), Cone Penetration Test (CPT), Field Vane Test (FVT) and the laboratory test in order to investigate the correlationships for the strength parameters obtained from Busan and Incheon areas. Many proposed correlation formulas also make a comparative study and new correlation formulas for domestic soils are introduced. Limit pressure ( $P_1$) could be determined by P-log($\Delta$V/V) and Relative volume Method. PMT for the granular soils showed relatively high correlation with SPT, while CPT has good correlation with PMT for cohesive soil. The predicted undrained shear test ( $S_{u}$) by the PMT test results for Incheon and Busan samples showed low correlativity with proposed equations, therefore, new correlation formulas are proposed for domestic soils.s.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.7
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• pp.1780-1786
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• 1995

The main goal of the present study is to establish the techniques and methodolgies of turbine performance test through evaluating the objective turbine test piece, and checking the reliability of the self-developed test facility by performing a series of turbine tests under ambient temperature condition. A high speed coupling, a lubrication system and a test bed of the test facility were modified through a series of preliminary test in order to reduce the vibration and oil leakage. The flowrate control of the test facility and data acquisition were accomplished by using a software called "Labview" The measurement of shaft horse power and control of rotational speed according to the conditions of turbine rotation were performed by a separate system. The preliminary evaluation of the measured data suggests that the developed test facility and the test technique can be used reliably for the performance test of turbines with the minor improvement.provement.

• Journal of Aerospace System Engineering
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• v.9 no.1
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• pp.28-34
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• 2015

Armed aircraft of a basic trainer class installs external stores under wing box by using pylon and performs an operation such as weapon delivery and jettison, and should be designed to withstand all kinds of loads applied to external stores. The static strength test of pylons and wing box was performed to assess the static strength of pylon and their support structures for substantiation. Based on the test, the structures were verified to fully satisfy a given design requirement. In this paper, methods of test load generation of wing box and pylon, evaluation of test result data and design result of test set-up were presented. Comparing the FEM analysis with the same test data can lead to good match and reasonable deviation between both. Finally, based on the test and the analysis, the static strength of test article was substantiated and the reliability and effectiveness of analysis math model were obtained.