• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.2
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• pp.339-344
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• 2019

In this paper, a digital home electric overload alarm system based on DSP for smart home automation which can minimize electrical fire damage caused by an home electrical overload was made experimentally. To verify the validity of the home electrical overload alarm technology, an electric overload alarm performance evaluation system which can artificially generate the electrical overloads was designed, developed, and constructed, and the effectiveness of the overload alarm developed by the overload test was verified. In particular, an overload test EMTP model based on EMTP-RV was developed, and simulation and measurement results obtained from the overload test were compared, and the reliability of overload performance verification results was confirmed.

• Journal of the Korean Society of Propulsion Engineers
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• v.5 no.2
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• pp.38-43
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• 2001

In this study, the technique of the performance prediction on the finocyl-type dual-thrust rocket motor is developed, and the predicted data are compared with those of the static firing tests. The prediction is carried out with the separate calculations of the grain burning area and the performance of the rocket motor. When predicting the performance of the dual-thrust rocket motor, the different correction factors should be used at the boosting and sustaining phases. Otherwise, an error of prediction will follow. Reprediction using the separate correction factors shows good agreement with the test data within 0.5% error.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1997.10a
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• pp.99-104
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• 1997

기존의 천연가스 가스터빈 시스템을 IGCC 발전소에 적용함에 있어 야기되는 탈설계점효과를 고려할 수 있는 압축기 성능곡선의 예측방법을 제안하였다. 압축기 성능해석방법으로는 익렬요소방법에 전압력손실, 유동편차각 모델들을 결합하여 사용하였으며, 본 방법에 의한 예측결과와 실제 압축기 성능실험결과를 비교하였다. 예측결과가 다양한 압축기 운전조건에 대해 시험결과와 비교적 잘 일치하였으며, 이를 통해 본 예측방법이 IGCC 공정설계 및 성능평가시 가스터빈 탈설계점 효과를 분석할 수 있는 기본 모듈로 사용될 수 있을 것이다.

• Magazine of the Korea Concrete Institute
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• v.9 no.3
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• pp.189-197
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• 1997

This paper describes an experimental study on the seawater resistance of steel fiber reinforced concrete. The test methods adopted for this study are divided into long-term immersion test and acceleration test by wetting and drying. Tests were carried out to evaluate the procedures which were measured for nine months about reduction in dynamic modulus, length change and compressive strength. Resistance indicators are the water-cement ratio, the content of steel fiber, the content of fly ash, the immersion water(artificial seawater or freshwater) and the types of curing. The seawater resistance of the appropriate additions of steel fiber and fly ash have apparently increased.

• Journal of Radiation Protection and Research
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• v.23 no.1
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• pp.49-57
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• 1998

Domestic intercomparison study of the neutron personnel dosemeters was performed for the first time in Korea. Thirteen types of neutron dosemeters from twelve institutions took part in this intercomparison study and the $D_2O$ moderated Cf-252 source of KAERI was used for irradiation. Eight of the fifteen dosemeters submitted by each participant were divided into two groups and each group was irradiated with different doses of the simulated mixed fields of neutron and gamma. The participants assessed their dosemeter reading in terms of the personal dose equivalent, Hp(10), for both neutron and gamma dose. The ratio of the reported dose equivalent to the delivered dose equivalent for comparison between participants ranged from 0.55 to 1.34 for neutron, from 0.54 to 1.32 for gamma and from 0.75 to 1.20 for total dose. This intercomparison results show that all dosemeter processors, especially for neutron category, are able to pass the personnel dosemeter performance test which shall be enforced according to the ordinance of the MOST, No. 96-6.

• Journal of Advanced Navigation Technology
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• v.15 no.2
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• pp.181-188
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• 2011

A small UAVs(Unmaned Aerial Vehicles) have limited by the payload capacity which requires miniaturization of a navigation system. In this paper, the performance of the lightweight and small sized AHRS(Attitude Heading Reference System), which is self-developed, is evaluated at low acceleration environment. The designed AHRS adopts the commercial low-cost MEMS sensors. A quaternion-based attitude calculation method, which eliminates singularity with relatively simple algebra, is used. In an attitude correction algorithm, the Kalman filter is used with accelerometers and magnetometers combined. The fabricated AHRS is also evaluated with reference to a COTS(Commercial Off-The-Shelf) AHRS which reports a number of successful applications to a small UAVs. The test results show that the measurements from the fabricated AHRS provide proper attitude output data with acceptable amount of differences(horizontal axis 0.5$^{\circ}$, vertical axis 1.5$^{\circ}$) in test environment.

• Journal of the Korean Society for Railway
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• v.16 no.5
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• pp.394-401
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• 2013

Here we report the results of an experimental laboratory test to verify the applicability to railway bridges of a PSC I girder of which the upper flange thickness was increased to improve sectional performance. The thicker this flange is, the further upward the neutral axis is moved. If in this way the span length can be increased to 40m long, the bridge may be constructed with four girders instead of five. Therefore, construction cost could be lowered by reducing the weight of the long span structure due to increased sectional efficiency. It was also necessary to be certain that the dynamic performance of this relatively flexible structure would be applicable to railway bridges. Therefore numerical analysis, as well as static and dynamic tests, was carried out for a full-size PSC I girder. Based on these results, it was verified that the performance of the PSC I railway bridge satisfied the performance criteria of the design code.

• Fire Science and Engineering
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• v.33 no.4
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• pp.1-8
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• 2019

Reaction-to-fire performance of pipe insulation materials should be approved in accordance with KS standards prior to installing water-based suppression systems because several fire accidents are initiated from insulation materials around ceilings or concealed space. A small room test to evaluate the reaction-to-fire performance of the polyethylene foam and elastomeric pipe insulation materials was conducted according to ISO 20632. Different fire growth rate and heat release rate are observed depending on the materials and construction methods. In order to improve a fire safety, the reaction-to-fire performance of pipe insulation material needs to be subdivided with regard to the heat release rate and smoke generation. Furthermore, the characteristics of the applying space are also required to be considered. Subsidiary materials for installation process such as tape and adhesive are found to provide an adverse effect to maintain a fire safety.

• Aerospace Engineering and Technology
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• v.1 no.1
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• pp.147-152
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• 2002

In the preceding tests of Sub.(Ⅰ) engines, it was observed that the heat resistant capability of the engines was not enough, and the design of Sub.(Ⅰ) engines was modified to satisfy the mission requirement. Sub.(Ⅰ) Mod. engines have three major design parameters - the arrangement of main injectors, the impinging angle of main injectors and thermal barrier coating. More than 20 experiments were carried out to evaluate engine performance and heat resistance capability with respect to design parameters. Analysing the result of Sub.(Ⅰ) and Sub.(Ⅰ) Mod. engine tests, it is found that the decreased impinging angle, adopting the H-type arrangement(rather than radial type arrangement), and adopting the thermal barrier coating can increase heat resistance capacity substantially. The result show that the performance variation by design change is below 5 percents and the radial type arrangement of injectors has higher performance than H-type. However, the performance of 15°impinging angle engine is higher than that of 20°impinging angle engine, which is inconsistent to our expectation. High frequency instabilities may cause such phenomenon, which will be verified by a series of tests.

• New & Renewable Energy
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• v.7 no.4
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• pp.42-49
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• 2011

The objective of this paper is to suggest a new method of a wind turbine performance test. The performance test of a wind turbine is generally carried out in a wind tunnel. The test needs not only a high-accuracy measuring system but also durable structure to withstand high speed turbine rotation and wind flow. Therefore, we tried turbine performance test using a towing tank to improve stability and reliability. Because a turbine rotates more slowly and generates more torque in the water than in the wind tunnel under similarity conditions. In this study, we developed turbine performance test systems and verified the turbine test method using a towing tank through comparing results of the wind tunnel and the towing tank test.