• Title/Summary/Keyword: short test

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The Study on Countermeasures of Electromagnetic Force by Three Phase Short-Circuit Test of Underground Transmission Cable (송전케이블 삼상단락 실증시험을 통한 전자력 대책방안 연구)

  • Kang, Ji-Won;Park, Hung-Sok;Yoon, Jong-Keon;Kim, Yang-Sang;Hong, Dong-Suk;Chang, Woo-Seog
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.12
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    • pp.2342-2348
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    • 2009
  • Even though underground transmission cable is an essential transmission method to supply stable power for downtown and population center, the interaction of electromagnetic force by fault current is very large comparing to overhead transmission line due to restricted installation space such as tunnel, and close consideration is required for it. This paper presents countermeasures to reduce and release the effect of electromagnetic force with rope binding and installation of spacer and describes its efficacy through three phase short-circuit test, which will be utilized as basic materials for improvement and development of cleat, hanger, etc. to reduce and release effect of electromagnetic force in the future.

The Study of Characteristics evaluation of short-circuit tests for Power Transformers (변압기 단락강도시험 성능평가에 관한 고찰)

  • Roh, Chang-Il;Kim, Sun-Koo;Jung, Heung-Soo;Kim, Won-Man;Lee, Dong-Jun;Kim, Sun-Ho
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.913-914
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    • 2007
  • Power transformer shall be designed and constructed to withstand the mechanical and thermal stresses produced by external short circuits which include three-phase, single line to ground, double line-to-ground, and line-to-line faults on any one set terminals at a time. This paper presents the method of short-circuit test and means of evaluation during and after each test to judge the results of short-circuit tests.

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The Design of Lumped Constant Circuit for the Simulation of A Real 22.9 kV-y Distribution Line (22.9 kV-y 실긍장 배전선로 모의를 위한 집중정수회로의 설계)

  • Yun, Chul-Ho;Jeong, Yeong-Ho;Han, Yong-Huei
    • Proceedings of the KIEE Conference
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    • 1999.07c
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    • pp.1186-1188
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    • 1999
  • When we perform the test related to the power distribution system such as artificial fault test, protective coordination test, distribution automation test in short length test line, Lumped Constant Circuit, a kind of variable impedance, should be attached to the test line in order to make it equivalent to a real line in length electrically. In this paper we designed the positive sequence and zero sequence Lumped Constant Circuit with optimized inductor and resister for the modification of long, 16km, distribution line, when they are attached to the short, 4km, distribution test line.

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Effects of Oriental Medical Treatment on ADHD - A retrospective clinical survey - (ADHD에 대한 한방치료의 효과에 대한 후향적 관찰 연구)

  • Byun, Ki-Won;Kim, Joo-Ho;Kim, Jong-Woo;Chung, Sun-Yong
    • The Journal of Korean Medicine
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    • v.32 no.4
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    • pp.75-82
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    • 2011
  • Objectives: This case report aimed to evaluate whether oriental medical treatment was effective on ADHD through a records review of a local oriental medical clinic. Methods: We reviewed clinical charts of a local oriental medical clinic between December 2007 and September 2010 to select ADHD patients. Among those patients, for comparison before and after treatment, we selected cases which had at least twice Stroop test results and 2 months of treatment. Baseline, 3-month and 6-month Stroop test results were compared. Oriental medical treatment consisted of 2 months' herbal medicine, periodic acupuncture and exercise. Results: 1. 3-month data showed that subjects were 12 and improved word score and word-color score of Stroop test. 2. 6-month data showed that subjects were 20 and improved word score, color score, and word-color score of Stroop test. Conclusions: 1. Relatively short term herbal medication and exercise are effective on the word score and word-color score of the Stroop test. 2. After short term herbal medication, continuous exercise maintained the effects of short term oriental medical treatment. 3. We need to consider the balance of left and right as an important point of exercise, but further study is needed.

Short-term Toxicity Assay Based on Daphnid Feeding on the Microalga Scenedesmus subspicatus

  • Lee Sang-Ill;Park Jong-Ho;Lee Won-Ho;Yeon Ik-Jun;Lee Byoung-Chan;Cho Kyu-Seok;Choi Hyun-Ill
    • Fisheries and Aquatic Sciences
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    • v.9 no.1
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    • pp.38-43
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    • 2006
  • We developed and evaluated a method of short-term acute toxicity testing based on the feeding behavior of Ceriodaphnia dubia. In prior toxicity tests, neonates of C. dubia were hatched and cultivated with the addition of yeast only for the preparation of the transparent daphnid's gut. Scenedesmus subspicatus was supplied as food after 1 to 6 h of exposure to toxicants. The effects of 1-h and 6-h exposure time on test sensitivity did not significantly differ. A comparison of the short-term l-h acute toxicity test developed in this study to the standard 48-h acute toxicity test using heavy metals, cyanide, and pentachlorophenol indicated that the 1-h test provided an acceptable sensitivity level in toxicity testing of C. dubia..

Parameters Optimization of Impulse Generator Circuit for Generating First Short Stroke Lightning Current Waveform

  • Eom, Ju-Hong;Cho, Sung-Chul;Lee, Tae-Hyung
    • Journal of Electrical Engineering and Technology
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    • v.9 no.1
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    • pp.286-292
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    • 2014
  • This paper presents the parameters optimization technology for generating the first short stroke lightning current waveform($10/350{\mu}s$) which is necessary for the performance tests of components of lightning protection systems, as required under IEC 62305 and the newly amended IEC 62561. The circuit using the crowbar device specified in IEC 62305 was applied to generate the lightning current waveform. To find the proper parameters of the circuit is not easy because the circuit consists of two parts; circuit I, which relates to the front of current waveform, and circuit II, which relates to the tail. A simulation in PSpise was carried out to find main factors related to the front and tail of $10/350{\mu}s$. The lightning current generator was developed by utilizing the circuit parameters found in the simulation. In the result of experiments, new parameters of the circuits need to be changed because of the difference between the simulation and the experiment results. Using the iterative method, the optimized parameters of the circuits was determined. Also a multistage-type external coil and a damping resistor were proposed to make the efficiency of generation to enhance. According to the result in this paper, an optimized first short stroke lightning current waveform was obtained.

Short Form Versions of MacArthur-Bates Communicative Development Inventories - Korean (M-B CDI-K) (M-B CDI - Korean 축약판 개발)

  • Pae, So-Yeong;Kwak, Keum-Joo;Kim, Mi-Bae;Lee, Hyun-Suk;Jung, Kyung-Hee
    • Speech Sciences
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    • v.15 no.2
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    • pp.119-129
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    • 2008
  • The purpose of this study were to develop short form versions of MacArthur-Bates Communicative Development Inventories - Korean and to discuss clinical implications. Two short versions were developed: one for $9\sim17$ month-olds(including 69 words and 17 object manipulation skills) and the other for $18\sim35$ month-olds (including 128 words and 5 grammatical items). Short versions seemed to be representative of full versions and showed developmental validity. Short versions showed concomitant validity with SELSI which is a standardized test for Korean children under 37 month-olds. Norm tables for words and criteria for object manipulation and grammaticality are also provided. M-B CDI-K short versions could be used as a preliminary screening tool to identify Korean children with language impairment economically and efficiently. Cautions using short versions of M-B CDI-K are discussed.

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The Toxicity Test of Water Flea by Heartbeat Measurement (물벼룩의 심장박동을 이용한 독성실험)

  • Lee, Chan-Won;Kim, In-Kyung;Jeon, Hong-Pyo
    • Journal of Environmental Science International
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    • v.16 no.4
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    • pp.425-432
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    • 2007
  • The water flea has been used as a test organism of toxicity test for surface water. Toxicity test with water flea is categorized into two parts. One is acute toxicity test with observing immobility and mortality and the other is chronic toxicity test determined by survival and reproduction of water flea. Heartbeat measurement of water flea was designed as a short-term toxicity test in this study. Direct measurement of heartbeat under microscope by aid of video camera gives and early diagnosis of mortality in short time. Therefore, the effects of measuring illumination, measuring time, and non-feeding during the test on heartbeat of water flea was evaluated to establish a new test approach. Test organisms used in this study are Daphnia magna, a well standardizes toxicity test organism, and Simocephalus mixtus, a newly refined organism $IC_{50}$ values of these test organism by heartbeat measurement were compared and discussed. It was found that toxicity test by heartbeat measurement was a reproducible, easy and simple method accomplished in a few hours.

A Experimental Study on the Effect of Increasing Rudder Force on Turning Ability of Short Sea Shipping Ship (타력 향상이 근해운송선박의 선회 성능에 미치는 영향에 관한 실험적 연구)

  • Jun, Hee-Chul;Kim, Sang-Hyun;Kim, Hyun-Jun;Park, Hwa-Pyeong
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.18 no.6
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    • pp.591-596
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    • 2012
  • Recently, a vessel's maneuvering performance is considered to be an important subject to secure safety at short sea shipping. Especially the high turning performance, which is required to avoid the marine pollution by the ships that was grounded, becomes more severe. In this paper, we discuss the effect of increasing rudder force on turning performance of short sea shipping ship by free running test in towing tank. First of all, we make the 47K PC model ship and high-lift rudder using Coanda effect. And we make the free running test system for the turning test in towing tank. And also we perform the turing test of 47K PC model in several changes of Coanda jet momentum and evaluate the turing performance such as advance and tactical diameter. Finally, we confirm that the increasing of rudder force is very effective to improvement of turning performance of short sea shipping ship.

A Study on the Rheological Behavior Properties of Short-term Aged Asphalt Binder (단기노화 된 아스팔트 바인더의 유변학적 거동 특성에 관한 연구)

  • Park, Tae-Soon
    • International Journal of Highway Engineering
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    • v.7 no.4 s.26
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    • pp.203-210
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    • 2005
  • The penetration and viscosity tests have been used for the evaluation of the aged asphalt binder performance change. The improved test method has been required because the conventional tests could not evaluate the viscoelastic characteristics and the real behaviour of the aged asphalt binder. The conventional test methods using a different short term aged asphalt binder were tested and the test results were expressed as the penetration index and the residual penetration. The oscillatory and rotational mode tests were performed to find out the rheological characteristics of the short term aged asphalt binder in this study. The test results showed that the change of testing frequency, the speed of the vehicle effects the complex modules and phase angles. The creep compliance and shear viscosity also showed the different test results when the short term aged asphalt binders were tested. The rheological behavior should consider when the pavement design is conducted.

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