• 한국대기환경학회지
• /
• 제16권6호
• /
• pp.685-691
• /
• 2000

In order to provide basis for an accurate concentration determination of volatile organic compounds(VOCs) in air, four different institutions participated in simultaneous measurements of several VOC species under the experimental scheme of the Measurement and Analysis Division(MAD) of the Korea Society for Atmospheric Environment(KOSAE). Two types of experiments were undertaken by collecting and analyzing ambient air samples from the 7th floor of Natural Science Building, Han Tang University during two day periods of the late May 1998. The first typer of experiment was conducted as five consecutive experiments at 2-hour intervals by two institutions. On the other hand. the second type of experiment was performed as two -10hr sampling by three different institutions. The data obtained from different type of experiments were examined using various statistical approaches. In general, the results of these experiments indicated that the VOC data produced by a number of Korean institutions be fairly agreeable.

• Nuclear Engineering and Technology
• /
• 제52권11호
• /
• pp.2499-2510
• /
• 2020

We performed 3-D (3-dimensional) IVR (In-Vessel Retention) natural convection experiments simulating the oxide layer in the three-layer configuration, varying the aspect ratio (H/R). Mass transfer experiment was conducted based on the analogy to achieve high Ra_H's of 1.99 × 10¹²-6.90 × 10¹³ with compact facilities. Comparisons with 2-D (2-dimensional) experiments revealed different local heat transfer characteristics on upper and lower boundaries of the oxide layer depending on the H/R. For the 3-D shallow oxide layer, the multi-cell flow patterns appeared and the number of cells was considerably increased with the H/R decreases, which differs with the 2-D experiments that the number of cells was independent on H/R. Thus, the enhancement of the downward heat transfer and the mitigation of the focusing effect were more noticeable in the 3-D experiments.

• 한국신뢰성학회지:신뢰성응용연구
• /
• 제18권2호
• /
• pp.173-183
• /
• 2018

Purpose: It is critical to design a set of experiments in Test and Evaluation Process for a weapon system. Because there is no sufficient resources in real-world, one must choose a subset of experiments which is considered to be more important. Methods: We introduce an optimization model for choosing the subset of experiments by considering a priority of experimental variable and level and restrictions of resources. We describe in detail how we construct objective function and constraints which must be a right realization of our logic and assumption. Conclusion: Since our optimization model turns out to be computationally difficult to solve, we introduce an algorithm for reducing the size of problem. Various computational results follows.

• 공학교육연구
• /
• 제13권3호
• /
• pp.87-95
• /
• 2010

본 연구의 목적은 화학실험 교과목에서 ARCS 동기모형을 적용한 교수자료를 개발하고 이를 적용하는 것이다. 이를 위해 요구분석(교수, 학생, 실험조교), 교과내용분석, ARCS 이론을 적용한 교수자료 설계, 개발, 적용, 효과분석을 하였다. 본 연구에서 개발된 교수자료를 적용한 결과, 실험에 대한 이해, 흥미, 동기부여, 집중정도, 실험과 이론을 연결하여 이해하는 능력이 증가하였고 실험시간은 단축되었으며 실험의 오차 범위가 줄어들었다. 그리고 안전사고 예방, 학생들이 실험에 대한 막연함 등을 해결하는데 효과가 있는 것으로 나타났다.

• 디지털콘텐츠학회 논문지
• /
• 제14권2호
• /
• pp.161-169
• /
• 2013

자연과학에 있어서 실험실습은 중요한 과정이다. 그러나 실험 과정에 대한 선행학습을 통해 자연과학 전공자들은 위험한 실험을 인지할 수 있고, 이를 통해 실제 실험에서의 위험을 피할 수 있다. 모바일 어플리케이션인 가상 실험 콘텐츠는 학습자에게 안드로이드 스마트폰이 가지고 있는 다양한 센서를 통해 상호작용을 제공한다. 그리고 본 논문에서 개발한 가상 실험 콘텐츠를 통해 학습자들은 화학 실험실습 도구를 다룰 수 있는 선행 학습을 수행하게 된다. 본 논문은 학습자들의 실험 능력을 향상시키기 위한 가상 실험 콘텐츠를 설계하고 개발하였다.

• Nuclear Engineering and Technology
• /
• 제41권6호
• /
• pp.753-764
• /
• 2009

JAEA started the LSTF experiments in 1985 for the fourth stage of the ROSA Program (ROSA-IV) for the LWR thermal-hydraulic safety research to identify and investigate the thermal-hydraulic phenomena and to confirm the effectiveness of ECCS during small-break LOCAs and operational transients. The LSTF experiments are underway for the ROSA-V Program and the OECD/NEA ROSA Project that intends to resolve issues in thermal-hydraulic analyses relevant to LWR safety. Six types of the LSTF experiments have been done for both the system integral and separate-effect experiments among international members from 14 countries. Results of four experiments for the ROSA Project are briefly presented with analysis by a best-estimate (BE) code and a computational fluid dynamics (CFD) code to illustrate the capability of the LSTF and codes to simulate the thermal-hydraulic phenomena that may appear during SBLOCAs and transients. The thermal-hydraulic phenomena dealt with are coolant mixing and temperature stratification, water hammer up to high system pressure, natural circulation under high core power condition, and non-condensable gas effect during asymmetric SG depressurization as an AM action.

• 대한지구과학교육학회지
• /
• 제14권3호
• /
• pp.267-276
• /
• 2021

이 연구의 목적은 계절별 별자리 실험에 대해 알아보고, 학교 급별로 효과적인 계절별 별자리 실험이 무엇인지 연구하는데 있다. 초등 예비교사 24명과 함께 계절별 별자리 실험을 정리하고, 학교 급별로 효과적인 실험이 무엇인지 쓰도록 하였다. 그 결과 초등학교에서는 역할놀이를 통한 직접적인 체험활동을 통한 별자리 학습이 가장 효과적이었고, 중·고등학교에서는 stellarium 프로그램을 이용하여 사실적으로 계절별 별자리의 변화를 관찰하고 추리해보는 활동을 효과적인 실험으로 선택하였다. 예비교사는 초등학교에서는 직접적인 체험과 구체적인 조작활동이 강조되는 실험을, 중·고등학교에서는 사실적인 자연현상의 관찰과 이를 통한 추리 활동이 강조되는 실험이 효과적이라고 인식하였다.

• 한국과학교육학회지
• /
• 제28권7호
• /
• pp.768-778
• /
• 2008

The most important factor in students' growth and development is the teacher. Therefore in-service science teacher education to develop the professionality is important as well as the selection of new excellence teachers. Our research is on the development and application of new education program on science experiments where in-service teachers become the lecturers in the program and provide information that is bound to the context of real lessons. This program is consisted of following 10 steps of work, which was implemented in 5 months: sharing the philosophy of the program, selecting science experiments, first application of the experiments, discussion on the first application, learning how to edit the movie clips of the lesson, second application of the experiments, in depth discussion on the second application, developing the experiment package, giving lecture to other science teachers, and evaluating the program. We describe the process of the program developed and implemented in detail to suggest a model of science teacher education program on science experiments and discuss educational implications. This program is characterized by the emphasis of the context closely linked to the real lessons, the problem solving in a real situation, and the collaboration of teachers, professors and science education researcher in a teacher education.

• Nuclear Engineering and Technology
• /
• 제47권5호
• /
• pp.608-616
• /
• 2015

The migration of silver (Ag) in silicon carbide (SiC) and $^{110m}Ag$ through SiC of irradiated tristructural isotropic (TRISO) fuel has been studied for the past three to four decades. However, there is no satisfactory explanation for the transport mechanism of Ag in SiC. In this work, the diffusion coefficients of Ag measured and/or estimated in previous studies were reviewed, and then pre-exponential factors and activation energies from the previous experiments were evaluated using Arrhenius equation. The activation energy is $247.4kJ{\cdot}mol^{-1}$ from Ag paste experiments between two SiC layers produced using fluidized-bed chemical vapor deposition (FBCVD), $125.3kJ{\cdot}mol^{-1}$ from integral release experiments (annealing of irradiated TRISO fuel), $121.8kJ{\cdot}mol^{-1}$ from fractional Ag release during irradiation of TRISO fuel in high flux reactor (HFR), and $274.8kJ{\cdot}mol^{-1}$ from Ag ion implantation experiments, respectively. The activation energy from ion implantation experiments is greater than that from Ag paste, fractional release and integral release, and the activation energy from Ag paste experiments is approximately two times greater than that from integral release experiments and fractional Ag release during the irradiation of TRISO fuel in HFR. The pre-exponential factors are also very different depending on the experimental methods and estimation. From a comparison of the pre-exponential factors and activation energies, it can be analogized that the diffusion mechanism of Ag using ion implantation experiment is different from other experiments, such as a Ag paste experiment, integral release experiments, and heating experiments after irradiating TRISO fuel in HFR. However, the results of this work do not support the long held assumption that Ag release from FBCVD-SiC, used for the coating layer in TRISO fuel, is dominated by grain boundary diffusion. In order to understand in detail the transport mechanism of Ag through the coating layer, FBCVD-SiC in TRISO fuel, a microstructural change caused by neutron irradiation during operation has to be fully considered.

• 한국사회정책
• /
• 제25권1호
• /
• pp.71-96
• /
• 2018

세계화의 확대와 탈산업화, 그리고 기술의 혁명적 발전은 현존하는 사회보장제도에 대한 우려로 이어지고 있으며, 기본소득은 미래 사회보장의 대안으로서 크게 주목받고 있다. 그러나, 기본소득제도의 도입 여부에 대해서는 찬성과 반대의 논리가 서로 팽팽히 맞서고 있기에 어느 한쪽의 주장을 쉬이 받아들이기 어려운 것이 사실이다. 이러한 상황에서 몇몇 정부에서는 정책실험을 통해 기본소득이 가져올 정치 경제적 영향력을 경험적으로 측정하고, 이를 바탕으로 향후 기본소득제도의 도입여부를 결정하려 한다. 본 연구는 이 중 가장 주목을 받고 있는 두 나라, 핀란드와 네덜란드의 기본소득 실험을 방법론적 관점에서 살펴보고자 한다. 이들 두 나라에서의 실험결과는 한국을 비롯한 전 세계 복지국가에서 기본소득 찬반론에 커다란 영향을 미칠 것이 자명하다. 그러나, 양국의 실험결과를 그대로 받아들이는 것은 위험하며, 실험의 방법론적 의미와 한계를 정확하게 파악하는 것이 앞으로의 기본소득 도입 논의에 반드시 필요하다. 그 이유는 양국에서의 실험이 정부의 개입 등으로 기본소득의 일부 특성만을 반영하거나, 실험 설계의 취지가 상당 부분 퇴색되었기 때문이다. 따라서, 찬반 진영의 어느 한쪽에서 실험 결과를 그대로 자신들의 주장 강화에 이용하는 것은 바람직하지 않다. 이보다는 이들 실험의 한계를 이해하고 제한적인 교훈만을 얻는 것이 중요하다. 본 연구는 핀란드와 네덜란드의 실험을 면밀히 고찰하여 그 방법론적 의미와 한계를 밝히고 더 나아가 만약 한국에서 기본소득 실험이 설계된다면 이들 국가들에서의 경험이 제공하는 시사점을 도출한다.