• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.508-512
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• 2004

This paper described operation and vibration characteristics of 'Tail-Fan' performance test system. KARI(Korea Aerospace Research Institute) developed 'Tail-Fan' system as a kind of helicopter anti-torque system(ATS) and designed ATS performance test-rig for Tail-Fan system performance test. Test-rig consists of driving parts, supporting parts and rotating parts. For Tail-Fan system performance tests, firstly, test-rig operation tests were carried out for verification of design specifications. Secondly, natural frequencies of fan blade and test-rig were measured respectively. Lastly, to find the operation rotating speed for performance tests, vibration tests using accelerometers on tail gear box(TGB) were carried out. Through the fanplot and vibration test results, Tail-Fan performance test conditions to avoid a resonance were found and performance tests were well done safely.

• Journal of the Korean Society for Railway
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• v.9 no.3 s.34
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• pp.330-334
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• 2006

To maintain design-knowledge database and manage configuration for requirement of performance tests and safety standards of High Speed Railway(HSR), It is established that management system of performance tests and safety standards and then constructed that design-knowledge database and documented a performance test and safety specifications for supporting performance test and safety system using Model-Based Systems Engineering(MBSE) tool.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3236-3240
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• 2007

This paper describes the results of steam turbine performance tests. The objectives of performance test is to exactly evaluate the degradation(decrease in performance) of the coal-fired steam turbine generator in order to provide plant information to help performance engineers identify problems, improve performance, and make economic decisions about scheduling maintenance and optimizing operation. To achieve these goals, the periodic thermal performance tests have been carried out since the initial operation period, 1997. We made the calculation program and guidelines for the tests and developed the performance index of the turbine cycle on the basis of the ASME PTC. By comparing the performance changes throughout the whole operation period, we confirmed the performance reliabilities of the turbine and its conditions.

• Journal of the Earthquake Engineering Society of Korea
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• v.28 no.3
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• pp.141-147
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• 2024

Earthquakes of magnitude 3.0 or greater occur in Korea about 10 times on average yearly, and the number of earthquakes occurring in Korea is increasing. As many earthquakes have recently occurred, interest in the safety of nuclear power plants has increased. Nuclear power plants are equipped with many cabinet-type control facilities to regulate safety facilities, and function maintenance is required during an earthquake. The seismic performance of the cabinet is divided into structural and functional performances. Structural performance can be secured during the design procedure. Functional performance depends on the vibration performance of the component. Therefore, it is necessary to confirm the seismic performance of the components. Generally, seismic performance is confirmed through seismic simulation tests. When checking seismic performance through seismic simulation tests, it is difficult to determine the effect of frequency and maximum acceleration on an element. In this paper, shaking table tests were performed using various frequencies and various maximum accelerations. The seismic performance characteristics of the functions of electrical equipment components were confirmed through tests.

• Education of Primary School Mathematics
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• v.9 no.2 s.18
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• pp.107-118
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• 2005

The purposes of this study were to investigate the practice of performance assessment in elementary mathematics classes especially focused on 4th grade. To achieve this, three research questions were posed as follow: First, What do they prepare for performance assessment? Second, What kinds of tests do they use in mathematics performance assessment? Third, What kinds of difficulties do they have for performance assessment and what should be changed for a successful performance assessment in mathematics? To Answer the research questions, three 4th grade classes were selected from three different elementary schools in seoul and three teachers were interviewed. From the data analysis, several conclusion were drawn. First, a plan for mathematics performance assessment was not set by the class teacher who are in charge of the class. The main reason was lack of time. Second, in most of the assessment, written tests were used and the items in the tests were skill-oriented. Third, teachers thought that performance assessment was needed in mathematics. But lack of their time, knowledge and competency, it is difficult to do performance assessment in mathematics.

• Structural Engineering and Mechanics
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• v.59 no.2
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• pp.291-312
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• 2016

Seismic performance evaluation of shear wall is essential as it is the major lateral load resisting member of a structure. The ultimate load and ultimate drift of the shear wall are the two most important parameters which need to be assessed experimentally and verified analytically. This paper comprises the results of monotonic tests, quasi-static cyclic tests and shake-table tests carried out on a midrise shear wall. The shear wall considered for the study is 1:5 scaled model of the shear wall of the internal structure of a reactor building. The analytical simulation of these tests is carried out using micro and macro modeling of the shear wall. This paper mainly consists of modification in the hysteretic macro model, developed for RC structural walls by Lestuzzi and Badoux in 2003. This modification is made by considering the stiffness degradation effect observed from the tests carried out and this modified model is then used for nonlinear dynamic analysis of the shear wall. The outcome of the paper gives the variation of the capacity, the failure patterns and the performance levels of the shear walls in all three types of tests. The change in the stiffness and the damping of the wall due to increased damage and cracking when subjected to seismic excitation is also highlighted in the paper.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.425-430
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• 2005

This Study presents to be Agitator maintenance for Water and Wastewater treatment Plant. This procedures offers methods of Design Creteria and performance tests on mixing equipment. These tests may be conducted to determine process performance, mechanical reliability. or suitability of equipment for the intended use. The reasons for conducting performance tests can be varied, but the methods presented should be generally applicable to most situations.

• PNF and Movement
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• v.8 no.1
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• pp.41-50
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• 2010

Pain originating from the sacroiliac joint(SIJ) has been associated with poor performance, yet specific diagnosis of sacroiliac dysfunction(SID) has been difficult to achieve. Clinical presentation of SID appears that pain and poor performance is responsive to local analgesia of periarticular structures with poorly defined pathology, and poor performance with bony pathological changes present as a result of chronic instability. Previous research indicates that physical examination cannot diagnose SIJ pathology. Earlier studies have not reported sensitivities and specificities of composites of provocation tests known to have acceptable inter-examiner reliability. Tests based on mechanics as manual provocation for SIJ pain have formed the basis of tests used to diagnose SIJ dysfunction. In this review summary, the purpose of this study was to describe the sacroiliac tests with a model of examination, diagnosis, and management of SID. Further research is warranted to determine whether SIJ tests is reliable means of evaluating innominate impairments.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.381-382
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• 2006

A comparative study is made on root bending fatigue performance of spur gears and plane bending fatigue performance of notched test bars. R = 0 root bending fatigue tests are made on small spur gears with critical root radius 1.0 mm. The results are compared to plane bending fatigue tests of 0.9 mm radius notched specimens. Results are presented for tests on 4%Ni/2%Cu/1.5%Mo prealloyed PM steel with addition of about 0.6% graphite. Predicted values from the test bars coincide well with the results obtained from the gear root fatigue tests.

• Journal of the Korea Institute of Military Science and Technology
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• v.6 no.4
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• pp.113-123
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• 2003

Both numerical analysis and experiment of cold and hot tests were performed to obtain basic design data for the swirl coaxial type Injector and to predict the combustion performance. Mass distribution, mixing distribution, mixing efficiency, characteristic velocity efficiency were measured by the cold tests and numerical analysis using the commercial thermo-hydraulic program. Test and analysis variables were recess, pressure drop, velocity ratio, mixing spray, mixture ratio. Hot tests were performed for the Uni-element injector to compare the performance with the cold test results, and, hot tests for Multi-element injector were performed to compare the performance with Uni-element injector. Designed thrust of the Uni-element injector liquid rocket was 35kgf at sea level and combustion chamber pressure, 20bar. Kerosene and Lox were used as a propellant.