• Title/Summary/Keyword: Experiments

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Experiments for Wave Transformation of Regular and Irregular Waves over a Submerged Elliptic Shoal(I) : Non-breaking Conditions (타원형 수중천퇴상의 규칙파 및 불규칙파의 전파변형 실험(I):비쇄파조건)

  • 이종인;이정욱
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.14 no.3
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    • pp.240-246
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    • 2002
  • Hydraulic model experiments were conducted fur a series of regular and uni-directional irregular waves propagating over a submerged elliptic shoal. Two different sets of experiments have been studied; one considers regular wave transformation with no breaking, and the other considers uni-directional irregular wave with partial breaking on top of the shoal. The numerical experiments are also performed using a numerical model based on the parabolic approximation equation. The result of the numerical experiments are compared with that of hydraulic experiments.

A Study on New Method for Teaching Family Resource Management with Classroom Experiments (교실 실험법을 활용한 새로운 가정자원관리 교육 방안에 관한 연구)

  • Cho, You-Hyun
    • Journal of Family Resource Management and Policy Review
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    • v.13 no.4
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    • pp.39-52
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    • 2009
  • The purpose of this research is to introduce a new method for teaching family resource management using classroom experiments. Classroom experiments are very attractive in the sense that students are placed directly into the various environments being studied, and they enhance the effectiveness of the Socratic Method, as opposed to traditional lectures. The family resource management approach focuses on the resource allocation behavior of families in the utilization of their human and non-human resources to achieve goals. Therefore, there are many family resource decision situations to which classroom experiments may be fruitfully applied. Within this context, this research provides useful implications for applying managerial concepts of family resource management behavior in practical situations. The study results might be used to analyze an interactive framework that facilitates discussions of classroom experiments, family resource management behavior and human ecology.

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Analysis of Middle School Biology Experiments by Vee Diagram (Vee Diagram을 이용한 제 5차,6차 교과서의 실험.관찰의 비교분석 - 중학교 2학년 생물단원을 중심으로 -)

  • Park, Sung-Eun;Hur, Myung
    • Journal of The Korean Association For Science Education
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    • v.16 no.3
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    • pp.260-269
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    • 1996
  • Middle school biology experiments were analyzed by Vee Diagram. Major findings of this study are as follows : 1. Principles were not explit in the most of the experiments. 2. The knowledge included in the experiments has rapid progress when compared with the experimental procedure. 3. The concepts were not consistent with the interaction of knowledge claim and previous knowledge. 4. Though some experiments were improved in the 6th Curriculum, many experiments did not mention value claims.

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Experimental Designs for Computer Experiments and for Industrial Experiments with Model Unknown

  • Fang, Kai-Tai
    • Journal of the Korean Statistical Society
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    • v.31 no.3
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    • pp.277-299
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    • 2002
  • Most statistical designs, such as orthogonal designs and optimal designs, are based on a specific statistical model. It is very often that the experimenter does not completely know the underlying model between the response and the factors. In computer experiments, the underlying model is known, but too complicated. In this case we can treat the model as a black box, or model to be unknown. Both cases need a space filling design. The uniform design is one of space filling designs and seeks experimental points to be uniformly scattered on the domain. The uniform design can be used for computer experiments and also for industrial experiments when the underlying model is unknown. In this paper we shall introduce the theory and method of the uniform design and related data analysis and modelling methods. Applications of the uniform design to industry and other areas are discussed.

Impact of Cumulus Parameterization Schemes with Different Horizontal Grid Sizes on Prediction of Heavy Rainfall (적운 모수화 방안이 고해상도 집중호우 예측에 미치는 영향)

  • Lee, Jae-Bok;Lee, Dong-Kyou
    • Atmosphere
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    • v.21 no.4
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    • pp.391-404
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    • 2011
  • This study investigates the impact of cumulus parameterization scheme (CPS) with different horizontal grid sizes on the simulation of the local heavy rainfall case over the Korean Peninsula. The Weather Research and Forecasting (WRF)-based real-time forecast system of the Joint Center for High-impact Weather and Climate Research (JHWC) is used. Three CPSs are used for sensitivity experiments: the BMJ (Betts-Miller-Janjic), GD (Grell-Devenyi ensemble), and KF (Kain-Fritsch) CPSs. The heavy rainfall case selected in this study is characterized by low-level jet and low-level transport of warm and moist air. In 27-km simulations (DM1), simulated precipitation is overestimated in the experiment with BMJ scheme, and it is underestimated with GD scheme. The experiment with KF scheme shows well-developed precipitation cells in the southern and the central region of the Korean Peninsula, which are similar to the observations. All schemes show wet bias and cold bias in the lower troposphere. The simulated rainfall in 27-km horizontal resolution has influence on rainfall forecast in 9-km horizontal resolution, so the statements on 27-km horizontal resolution can be applied to 9-km horizontal resolution. In the sensitivity experiments of CPS for DM3 (3-km resolution), the experiment with BMJ scheme shows better heavy rainfall forecast than the other experiments. The experiments with CPS in 3-km horizontal resolution improve rainfall forecasts compared to the experiments without CPS, especially in rainfall distribution. The experiments with CPS show lower LCL(Lifted Condensation Level) than those without CPS at the maximum rainfall point, and weaker vertical velocity is simulated in the experiments with CPS compared to the experiments without CPS. It means that CPS suppresses convective instability and influences mainly convective rainfall. Consequently, heavy rainfall simulation with BMJ CPS is better than the other CPSs, and even in 3-km horizontal resolution, CPS should be applied to control convective instability. This conclusion can be generalized by conducting more experiments for a variety of cases over the Korean Peninsula.

Patterns of Designing Tools Experiments with Types of Force Conceptions in Elementary School Students (초등학생의 힘 개념에 따른 연모 실험 설계의 유형)

  • Kwon, Sung-Gi;Park, Jong-Du
    • Journal of The Korean Association For Science Education
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    • v.24 no.3
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    • pp.583-595
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    • 2004
  • The purpose of this study was to identify whether the elementary school students force conceptions may influence on designing tools experiments. Four questions with multiple choices and reasons for those choices were asked to identify scientific/alternative force conception. Also four tasks for tools experiments matched to each force conceptions were developed into open questions in hypothesizing. controlling variables and methods of experiments. Forty elementary students were selected from 4 classes in sixth grade of a school in Daegu city. The major findings of this study were that the types of force conceptions can be classified into scientific and alternative conceptions. The patterns of designing experiments could be identified with types of hypothesis, controlling variables and methods of experiments in each four tools experiments. But students those who had scientific force conception did not better in hypothesis, methods of controlling variables and results for simple experiment than those who had alternative force conceptions. These results imply that students' force conception did not influence on designing tools experiments. The assumption that scientific conception could improve designing experiments was not guaranteed by this results.

Reconsidering the Meanings of Experiments and Instruments Based on the Analysis of Chemistry Experiments in Textbooks (교과서의 화학 실험 분석을 통해 본 실험과 도구의 의미 재고)

  • Choi, Chui Im;Lee, Sun-Kung
    • Journal of the Korean Chemical Society
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    • v.60 no.4
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    • pp.267-275
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    • 2016
  • Experiment is recognized as an important part in science and science education. Scientists do experiments for verifying or refuting theory and they take many forms to do experiments. One of the central goals of science education is to improve inquiry ability. So we have taken for granted that students engage in authentic inquiry and experiment which scientists carry out to research. But it is not always positive about discussions and opinions what school experiment and its role is in learning science and understanding about science. There is certainly a gap between experiments which scientists and students do even though there is a theoretical basis of school science experiment. In this study, we discussed how scientific inquiry and school inquiry are different, and what it means to use instrument in school science experiment. And as a case, we analyzed chemistry experiments in science textbook and manipulation level of instruments which were handled in chemistry experiments, we shed light on the meanings of experiments and instruments in school science inquiry based on the result of experiments and instruments analysis.

The Characteristics of 3rd Grade Elementary School Students' Reasoning in Small Group Argumentation including Experiments (실험을 포함한 소집단 논증활동에서 나타나는 초등학교 3학년 학생들의 추론 특징)

  • Na, Jiyeon;Yoon, Hye-Gyoung
    • Journal of Korean Elementary Science Education
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    • v.37 no.1
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    • pp.12-26
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    • 2018
  • The purpose of this study was to investigate the characteristics of reasoning in which $3^{rd}$ grade elementary school students form ideas, design experiments, and interpret the results to solve problems in small group argumentation. For this purpose, 12 3rd-grade students' small group argumentations including experiments were observed. The researchers analyzed students' pre- and post-open questionnaires, field notes, and video recordings of small group argumentation. The results of the research are as follows. First, in the initial opinion formation process, a hasty unification of opinions and a transformation of inquiry problem occurred. In the design and execution of experiments, verification experiments and unplanned and arbitrary experiments were performed. They also selectively noticed or accepted claims, evidence, interpretation, and criticism. They could distinguish between the condition and the cause, but they were confused by using inaccurate terms and tended to keep the initial opinions when interpreting the results and drawing conclusions.

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

  • Kim, Mi-Kyung;Oh, Hee-Gyun;Park, Jong-Won
    • Journal of The Korean Association For Science Education
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    • v.16 no.1
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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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CURRENT STATUS OF THE EAVN EXPERIMENTS

  • HAGIWARA, YOSHIAKI;AN, TAO;JUNG, TAEHYUN;RHO, DUK-GYOO;ZHANG, MING;HAO, LONGFEI;FUJISAWA, KENTA;YONEKURA, YOSHINORI;BAAN, WILLEM;KIM, JONGSOO;KOBAYASHI, HIDEYUKI
    • Publications of The Korean Astronomical Society
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    • v.30 no.2
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    • pp.641-643
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    • 2015
  • VLBI experiments have been conducted by radio telescopes in the East Asia VLBI Network (EAVN) in which 14 telescopes in China, Japan, and Korea participated. One of the aims of the EAVN is to obtain higher angular resolution that is provided by the 6,000 km baseline between China and Japan and better sensitivity by adding large telescopes. Data were recorded at 1 a Gbps recording rate at all stations and processed on the Korea-Japan Joint VLBI Correlator (KJJVC) at the Korea-Japan Correlation Center (KJCC) after experiments. Fringes were obtained from these experiments conducted at 8 GHz and 22 GHz and post-correlation data analysis of the experiments is undergoing. The outcomes of these experiments open the possibility of conducting EAVN observations with global VLBI networks. In this presentation, the recent status of these experiments and future prospects are presented.