• Proceedings of the KSME Conference
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• 2000.04a
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• pp.37-42
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• 2000

The boiler tubes and steam Pipes operating both at high temperature and pressure for a long period of time in a power plant are degraded by creep because of internal pressure. So, the remaining life of a component is evaluated by the creep rupture strength. Although the conventional method to evaluate the creep damage is widely used, it has some disadvantages such as requires large size specimen and long employed to evaluate the correlation between fracture toughness and evaluation time. Recently, new method so called "small lunch test' is used to evaluate degradation of creep. In this study, a conventional creep test and a small punch test are conducted using 2.25Cr-1Mo steel which is mainly used for the boiler tubes and steam pipes in power plant. The creep life, approximately 1,500 hrs, is determined by conventional method under a severe condition then specimens for a small Punch test are obtained after certain time intervals such as 1/4, 1/2 and 3/4 of final rupture time, respectively.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.185-186
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• 2015

The use of non-bearing lightweight wall has increased recently due to the increase of high-rise buildings and supply of long-life housing. Lightweight wall has advantages such as reducing the self-weight of the building, convenience in installation, and shortening construction period, however, must have a sufficient strength to external force. This study standardized the stiffness (static horizontal load resistance) test method for lightweight walls by using the actual impact load obtained through the load analysis test conducted in the previous studies. The size of specimen was set up as height 2.4m and width 3.0m. Test apparatus and test methods were referred to BS 5234-2:1992. However, the loading level applied to the specimen was divided into 3 steps (3000N, 1000N, 500N) that can be applied selectively depending on the purpose of the wall. The deformation characteristics according to the same loading level were vary depending on the specimen's type, and the evaluation criteria for functional damage may vary depending on the material, method of construction, and purpose of wall. Therefore, we did not suggest unified evaluation criteria of the stiffness to the test results.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.639-642
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• 1999

Pullout test known as Lok test among the test methods to evaluate concrete strength strength is a test method which is used to decide the form removal time by assessing the early strength of concrete in a new construction, or to control the quality of newly placed concrete. This method has inconvenience to place inserts on the form work in advance, however, the placing work is quite simple and it has advantage that the strength can be measured at field as long as the inserts are placed. In this study, the first step is to investigate the properties of test method itself, by performing the laboratory test which covers deviation of the method and factors affecting the results, etc. The second step is to correlate the result with cylinder strength and other NDT methods such as rebound hammer, ultrasonic method, etc. And that, the results are compared with foreign results to find the differences between the two. In this research, new factors such as moisture content, area of aggregate failure cross section and area of aggregate separation cross section, etc as well as wate-cement ratio and age are investigated.

• Journal of radiological science and technology
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• v.39 no.4
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• pp.631-636
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• 2016

Hitherto, spatial resolution has commonly been evaluated by test patterns or phantoms built on some specific distances (from close to far) between two objects (or double targets). This evaluation method's shortcoming is that resolution is restricted to target distances of phantoms made for test. Therefore, in order to solve the problem, this study proposes and verifies a new method to efficiently test spatial resolution with a single target. For the research I used PSF and JND to propose an idea to measure spatial resolution. After that, I made experiments by commonly used phantoms to verify my new evaluation hypothesis inferred from the above method. To analyse the hypothesis, I used LabVIEW program and got a line pixel from digital image. The result was identical to my spatial-resolution hypothesis inferred from a single target. The findings of the experiment proves only a single target can be enough to relatively evaluate spatial resolution on a digital image. In other words, the limit of the traditional spatial-resolution evaluation method, based on double targets, can be overcome by my new evaluation one using a single target.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.181-184
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• 2005

When concrete structures are exposed under marine condition for a long time, the steel in concrete is corroded due to the ingression of chlorides in the seawater. Because the damages of corrosion resulting from the chloride ion are very serious, many researches have been performed. However evaluation on chloride attack of concrete structures are not fully examined, recently. Therefore, the objective of this paper is to study the applicability of colormetric method. For the purpose of this, reaction mechanism of colormetric method were investigated, and the colormetric method is applied for marine concrete structures. According to the test results, the diffusion coefficient by colormetric method is not so different to the value of chloride concentration profile test. It is confirmed that the colormetric method is useful tool for estimating the chloride of concrete structures in situ. The average chloride amount of colored parts indicates 0.9kg/$m^{3}$ per concrete unit weight.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.28-35
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• 2003

In this paper, the ride comfort of a passenger coach installed with a KT23 type bogie was measured and evaluated through field test in operation routes. The ride comfort level was evaluated and analysed by ISO method and DIC method that were applied generally at railway fields. Particularly three evaluation methods, i.e., a simple method, a full standing method, and a full seating method of UIC513R standard, were fully applied to evaluate the ride quality. Also the vertical and lateral vibration levels on the floor were evaluated by peak-to-peak analysis method.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.10
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• pp.42-49
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• 1993

In this paper, we evaluate the quality of synthesized speech by rule using the LPC CD as a objective measure, and then compare the test result with the subjective one. Speech used for the test consists of 108 words which are selected by word construction method using Korean attribute and frequency distribution, synthesized by demi-syllable rule. By evaluating the quality of synthesized speech by reule objectively, we have tried to resolve the problems such as lots of evaluation time, expansion of test scale, and variables of analysis result arised by subjective measure. We have, also, proved the validity of the objective test using the LPC CD, by comparing intelligibility which is the index for the subjective quality evaluation of synthesized speech by rule with MOS. From this results, we can provide a guide for quality assessment that would be useful in the R&D of synthesis method and the commercial products using synthesized speech.

• Journal of Biomedical Engineering Research
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• v.30 no.5
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• pp.438-443
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• 2009

Nebulizer is designed to atomize medicinal fluid for patient with small particles(0.5-$5{\mu}m$) and also able to deliver particles from devices to the lungs when patient inhales air. Several particle size measurements are currently used to size aerosol particles. The most commonly used test is the cascade impactor method in as a standard. But, other methods for comparative particle size distribution data such as the particle size range and reproducibility are acceptable. Therefore, in this study a new test methode is suggested for nonventilatory nebulizer evaluation equipment.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1814-1820
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• 2010

Korean Train Express (KTX) has been commercially operating and achieving elevation on transport capacity since 2004. And the first hish-speed prototype test train, HSR-350x, was developed and succeeded in testing of running over 350km/h. Now KTX-II based on HSR-350x was started in service run. The new high-speed train development project, HEMU-400x project, has started since 2007. The protype train is being designed and manufactured. After the train are developed completely, it will run on the commercial line and will be test to verify the estimated performance. The authors devised the performance evaluation method and process of the HEMU-400x prototype system. And we introduce the definite performance test items and the method to vitrificate them in this paper.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.4
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• pp.431-436
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• 2008

We have extended an absolute evaluation method to obtain the ratio error and phase displacement of a current transformer (CT) up to primary current of 40,000 A by measuring four parameters of equivalent circuit in CT. The method was applied to CTs under test with the current ratios in the range of 5,000 A / 5 A - 40,000 A / 5 A. The ratio error and phase displacement of the CTs under test obtained in this study are consistent with those measured at the national institutes in Canada and Germany using the same CTs under test within an expanded uncertainty (k = 2) in the overall current ratios.