• 제목/요약/키워드: Experiment study

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Experiment of Hypersonic Waverider Vehicle

  • Lian, Xiaochun;Wu, Dingyi;Xiao, Hong
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2008년 영문 학술대회
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    • pp.105-108
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    • 2008
  • The purpose of the current study is to examine the aerodynamic characteristics of hypersonic waverider vehicle by simulation and experiment. The simulation was accomplished using NS aerodynamic codes developed in Northwestern Polytechncal University. The objective of experiment are twofold. The first is to examine the accuracy of simulation. The second is to examine the effects of shockwave an d boundary layer interactions on aero dynamic performance hypersonic configurations.

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후방추돌평가 시험을 위한 가상환경 시나리오 개발연구 (A study on scenario in virtual environment for test about rear-end collision)

  • 백우경;김배영;김시우;정충민;송종원;서명원
    • 자동차안전학회지
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    • 제3권2호
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    • pp.17-21
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    • 2011
  • Vehicle safety device such as active headrest and rear detection system has been developing as people are interested about rear end collision more than head on or than front. However, there is no any standard or criterion in order to evaluate vehicle safety device for rear end collision. Also there is no test protocol about rear end collision in vehicle experiment. Therefore, this research developed scenario for experiment about rear end collision in vehicle experiment. Also this research evaluated dangerousness about vehicle test and fitness about re-enacting rear end collision using scenario developed using commercial software (PC-Crash) which can re-enact vehicle collision in virtual vehicle experiment. Scenario developed according to statistics from National Highway Traffic Safety Administration and German In-Depth Accident Study. Scenario has twelve cases which composed of Re-LVS (Rear end Leading Vehicle Stop), Re-LVM (Rear end Lead Vehicle Moving) and scenario for evaluation about malfunction of active headrest.

Feasibility Study of High-Efficiency Ground Heat Exchanger using Double U-tube through a Real-Scale Experiment

  • Bae, Sangmu;Kim, Jaemin;Nam, Yujin
    • KIEAE Journal
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    • 제17권4호
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    • pp.33-39
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    • 2017
  • Purpose: The use of renewable energy system is essential for building energy independence and saving energy consumption in the building sector. Among renewable energy technologies, ground source heat pump(GSHP) system is more energy-efficient and environmental-friendly than other heat source systems due to utilize stable ground heat source. However, the GSHP system requires a high initial installation cost and installation space in limited urban area, so it is difficult to have superiority in the market of heat source system. Therefore, it is necessary to develop the installation method of low-cost and improve system performance. This paper aims to evaluate the performance of double u-tube ground heat exchanger(GHX) and verify system feasibility through real-scale experiment. Method: In this study, the real-scale experiment of vertical closed-type GSHP system was conducted using double u-tube GHX and high-efficiency grout. Through the verification experiment, heat source temperature, heat exchange rate(HER) and seasonal performance factor(SPF) were measured according to the long-term operation. In addition, the feasibility analysis was conducted comparing to the single u-tube system. Result: In the results of experiment, average HER was 136.27 W/m and average SPF was 5.41. Furthermore, compared to the single u-tube, the installation cost of the developed system could be reduced about 70% in the same heating load condition.

호흡 및 조음기관 훈련 프로그램이 뇌성마비아동의 말 산출 기초능력에 미치는 효과 (The Effect of Respiration and Articulator Training Programs on Basic Ability of Speech Production in Cerebral Palsy Children)

  • 이금숙;유재연
    • 음성과학
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    • 제15권3호
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    • pp.103-116
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    • 2008
  • Cerebral palsy children represent abnormal vocalization pattern caused by respiration problem and paralyzed oral motor muscle that are the basics of speech production. Thus, this study examined the effect of respiration and articulator training programs on the basic ability of speech production in CP children. The subjects of this study were 4 children with 3 of spastic CP and 1 of ataxia CP. The respiration and articulator program was conducted in 30 sessions for 30 minutes each. Pre-test was administered twice before the program, ongoing test was administered every 5 session during the period of experiment, and post-test was administered twice. The program included speech production such as respiration training, lips, jaw, cheek, and tongue exercise, and velopharyngeal training, and related articulator training. The following results were obtained. First, all subject children were less than 5 seconds in maximum phonation time before the experiment and 2 were improved by more than 4$\sim$5 seconds during the experiment, but 2 had relatively low rising width. Second, while children with less than 30dB before the experiment became bigger in strength during the experiment, children with more than 35dB before the experiment showed a minor change. Subject child 4 had lower vocal strength in the post-test period. Finally, although each subject had individual difference in syllable diadochokinetic ability, the function was improved and the number of repetition in one respiration was also increased.

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과학 실험 수업에 관한 한 초등학교 교사의 실천적 지식의 '구조' 분석 (Analysis of the 'Structure' of an Elementary School Teacher's Practical Knowledge on Science Experiment Lessons)

  • 조영미;오필석
    • 한국초등과학교육학회지:초등과학교육
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    • 제30권2호
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    • pp.162-177
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    • 2011
  • The purpose of this qualitative case study was to investigate the 'structure' of an elementary school teacher's practical knowledge concerning science experiment lessons. A female elementary teacher in the early career years participated in the study, and video recordings of her science experiment lessons as well as audio-taped interviews with her were analyzed by means of Elbaz's framework. The teacher expressed six images of science experiment lessons: 'Science is difficult', 'Experiments are dangerous', 'Experiments are accurate', 'A science experiment takes a long time', 'Science experiments are interesting', and 'Children are little scientists.' These images were supported by several principles and rules, most of which were clearly described. Among the images, principles, and rules, there were complex relationships with some working in synergy and some conflicting. In case of the image 'Children are little scientists', its subordinate principles and rules were not fully realized in the classroom. Implications for science teaching reform and science education research were discussed.

물리 탐구 실험의 평가를 위한 도구의 개발과 분석 (The Development and Analysis of a Test for Assessment of Physics Inquiry Experiment.)

  • 김미경;오희균;박종원
    • 한국과학교육학회지
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    • 제16권1호
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    • pp.51-60
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    • 1996
  • The purpose of this study is to develope and analyze a test for the assessment of physics inquiry experiment. To do this, three experiments about 'analysis of motion', 'the relation of force and acceleration', and 'free fall motion' in high school physics textbooks were chosen, and 5 scientific inquiry domains and 16 science process skills have been specified. For each experiments, test sheet of $29{\sim}44$ questions for assessing students' ability about physics inquiry experiment were developed on the basis of the scientific inquiry processes developed earlier. After instruction about 3 experiments mentioned above, a test was administered to the students who took experiment. After the adminstration of a test, the ratio of correct answers, discrimination index, and reliability were analyzed. Using the ratio of correct answers, we can determine item difficulty. Through the D.I(discrimination index), we can find which items can discriminate the students who took experiment well from those who took experiment badly, and we can also find the stability of a test result by the reliability analysis. The test developed in this study were also administered to the students who did not take experiments, and the results were compared with the those of the students who took experiments. With the comparison by chi-square method, we could find which items can discriminate the students who took experiments from those who did not take experiments.

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부가저항 실험의 불확실성 연구 (Uncertainty Study of Added Resistance Experiment)

  • 박동민;이재훈;김용환
    • 대한조선학회논문집
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    • 제51권5호
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    • pp.396-408
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    • 2014
  • In this study, uncertainty analysis based on ITTC(International Towing Tank Conference) Recommended Procedures is carried out in the towing-tank experiment for motion responses and added resistance. The experiment was conducted for KVLCC2 model in head sea condition. The heave, pitch and added resistance were measured in different wave conditions, and the measurement was repeated up to maximum 15 times in each wave condition in order to observe the uncertainty of measured data. The uncertainty analysis was carried out by adopting the ISO-GUM(International Organization for Standardization, Guide to the Expression of Uncertainty in Measurements) method recommended by ITTC. This paper describes the details about the analysis method, uncertainty and the measured uncertainty for each source. The uncertainty analysis results are summarized as a tabular form. To validate the accuracy of the present measurement, the experimental results are compared with the results of numerical computation and other experiment. From the present uncertainty analysis, the main sources of uncertainty are identified, which can be very useful to improve the accuracy for added resistance experiment.

The Effects of Syllable Boundary Ambiguity on Spoken Word Recognition in Korean Continuous Speech

  • Kang, Jinwon;Kim, Sunmi;Nam, Kichun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제6권11호
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    • pp.2800-2812
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    • 2012
  • The purpose of this study was to examine the syllable-word boundary misalignment cost on word segmentation in Korean continuous speech. Previous studies have demonstrated the important role of syllabification in speech segmentation. The current study investigated whether the resyllabification process affects word recognition in Korean continuous speech. In Experiment I, under the misalignment condition, participants were presented with stimuli in which a word-final consonant became the onset of the next syllable. (e.g., /k/ in belsak ingan becomes the onset of the first syllable of ingan 'human'). In the alignment condition, they heard stimuli in which a word-final vowel was also the final segment of the syllable (e.g., /eo/ in heulmeo ingan is the end of both the syllable and word). The results showed that word recognition was faster and more accurate in the alignment condition. Experiment II aimed to confirm that the results of Experiment I were attributable to the resyllabification process, by comparing only the target words from each condition. The results of Experiment II supported the findings of Experiment I. Therefore, based on the current study, we confirmed that Korean, a syllable-timed language, has a misalignment cost of resyllabification.