• Journal of Environmental Health Sciences
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• v.18 no.2
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• pp.1-2
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• 1992

실험기구의 청결도는 실험 및 분석에 있어서 생명과 같이 중용한 것으로 실험실에서 초자기구와 그외 기구, 그리고 장비 등을 사용하는 연구자와 실험요원들이 원하는 바는 이 기구들이 완전히 청결한 상태를 유지하는 것이다. 눈에 보이지 않는 찌꺼기들은 시료분석의 오차를 유발하고, 분리속도를 증가 또는 감소시키며, 미생물 실험에 있어서는 2차 감염이나 배양물 성장저해 그리고 신속성이 낮아지는 결과 등 많은 문제점을 초래하게 된다. 이러한 문제점을 해결하기 위하여 실험기구는 청결히 세척되어야 하며 어떠한 방해물질도 완전히 제거되어야 한다. 이는 바로 적절한 세척제를 선택하고 또한 효과적인 세척방법이 병행되어야 함을 뜻한다. 본 고에서는 세척제의 선택과 세척방법에 대하여 간략히 논해보고자 한다.

• Journal of the Korean Chemical Society
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• v.64 no.6
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• pp.379-388
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• 2020

The purpose of this study are to develop the TEP activity for learning experimental apparatus at elementary school and to test the effects of the TEP activity. This study consists of two steps. First through literature research on the difficulties and needs of experimental apparatus education developed the form that how to educate the experimental apparatus at elementary school. Second, applied the TEP activity and figured out the effects as two aspect(knowledge about experimental apparatus and actual using skill during lesson). This worksheet was applied to 3rd grade students in elementary school about 4 experimental apparatuses(Beaker, Electronic scale, Glass rod, Spatula). The results of this study are as follows: There is no specific time to teach what is and how to use experimental apparatus by regular curriculum. So many students and teachers need method and time to learn them. Also they want to lots of opportunities to use them. With that needs given previously, TEP activity developed by 3 steps. 1. Trigger interest 2. Explore experimental apparatus: learned knowledges about experimental apparatus focused on appearance(name, purpose, directions for use, precautions) 3. Practice experimental apparatus: actual using time to acquire skills. After that did the survey of knowledge and observation of students' behavior during usual class to confirm the effects. According to the results, TEP activity helped the students to improve there awareness of the experimental apparatus and actual using skills.

• Journal of Science Education
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• v.35 no.1
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• pp.80-90
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• 2011

The purpose of this study is to investigate manual skills of experimental apparatuses of pre-service elementary school teachers by examining and analyzing the process of experiments conducted by pre-teachers. For this study, 24 pre-service elementary school teachers were selected as the subjects and 4 experimental apparatuses were chosen through analyzing science textbooks from 3rd grade to 6th grade in elementary school. The selected experimental apparatuses were alcohol burner, dropper, microscope, instruments for making a prepared specimen. In addition, a task was carefully chosen to conduct an investigation in real settings and a series of evaluation standards was developed. While 3 subjects conducted experiments in separated and independent space at the same time, 3 collaborators observed the experiment process and recorded whether the subject met the evaluation standards or not, using O, X. The study suggests that pre-service elementary school teachers' manual skills of experimental apparatuses were under far below our projections. Particularly, in case of alcohol burner, the subjects showed lower ability to properly light the burners - which is to brush through the lampwick with fire - and to adjust the height of tripods according to the flame. Also, when it comes to dropper, they were not held the way they were supposed to be. In addition, when designing prepared specimen, the subjects used their hands instead of tweezers and often skipped the process of dripping water drop and wiping water with an oilpaper. Moreover, they did not know how to use a microscope properly so there were many times that they could not focus a microscope, failing to observe the objects. Educational implications are discussed.

• Journal of the Korea Concrete Institute
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• v.17 no.4 s.88
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• pp.513-520
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• 2005

The uniform truss mechanism is widely accepted as a shear transfer mechanism in reinforced concrete members. However, the uniform truss action cannot be expected when the bond stress distribution is not constant along longitudinal bars. A test method in which only the truss action takes place is developed and conducted to investigate the truss actions under various bond contributions. Based on the experimental results and analysis, the following findings can be obtained: 1) The bond stress distribution depends on the axial compression force, the amount of shear reinforcement and loading conditions. 2) The analysis using the combined truss model consisting of uniform and fan-shape trusses can predict the experimental results

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2013.04a
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• pp.12-13
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• 2013

국가화재안전기준(NSFC 301)에서 규정하고 있는 소방대상물별 피난기구를 선정하여 사용자 특성을 고려한 상황을 가상하여 행동실험을 통해 피난기구별 그 효용성을 비교 분석하였다. 단순한 체험실험을 통해서 얻어진 결과는 노인요양시설이나 유아교육시설과 같은 피난 시 협조자의 도움이 필요한 시설에서의 피난기구 선정은 현 기준에서 제시한 다수의 피난기구가 그 적응성이 떨어지는 것으로 나타났다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.11-14
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• 2007

현재, 새로운 조명광원으로서 백색 LED가 기대되고 있으며, 이를 이용하는 조명이 확대되어 실용화 될 것으로 예상된다. LED 광원을 이용하여 조명기구를 제작하고 이것을 실내조명으로 사용할 때 조명기구에 의한 글레어가 편안함을 주는지 불편함을 주는지에 대한 평가가 요구된다. 실내 조명환경에 대한 불쾌글레어를 평가하기 위해 UGR(Unified Glare Rating)을 추천하고 있다. 그러나 균일한 글레어 광원의 평균휘도를 이용하여 계산된 종래의 불쾌글레어 평가법들은 불균일한 휘도를 갖는 LED 조명기구에 대해서는 적용하기 어렵게 될 것으로 판단된다. 그래서 UGR를 이용하였을 경우, 균일한 휘도를 갖는 조명기구와 불균일한 휘도를 갖는 조명기구에 대해서 어떠한 차이가 있는지 다음의 불쾌글레어의 주관평가 실험을 수행하였다. 평균휘도가 같고 최대 휘도와 최소 휘도가 다른 조명기구(균일한 휘도를 갖는 조명기구 1종과 불균일한 휘도를 갖는 조명기구 2종)를 글레어 광원으로 사용하였다. 입체각(${\omega}$)과 위치지수(Position Index)를 고정시키고 배경휘도($L_b$)와 광원휘도($L_s$)를 임의로 변화시켰다. 주어진 환경에서 피험자로 하여금 얼마나 편안하진 또는 불편한지에 대한 느낌을 값으로 평가하도록 하였다. 우선, UGR과 주관평가 사이에 차이가 나타났으며, 이는 동 서양에 따른 문화적 및 생리적 차이에 기인한다고 생각된다. 다음으로 균일한 휘도를 갖는 조명기구보다 불균일한 휘도를 갖는 LED 조명기구가 더 높은 값을 할당 받아 LED 조명기구가 불쾌감을 더 유발시키는 것으로 나타났다. 또한 LED 소자 간격에 따른 영향은 글레어 광원의 휘도가 높아질수록 크게 나타났으며, 배경휘도에 대해서도 광원의 휘도가 높아질수록 LED 소자 간격의 차이에 의한 영향이 나타났다. 따라서 UGR식은 균일한 휘도를 갖는 조명기구에 적용하기에는 적합하지만, 불균일한 휘도를 갖는 조명기구에 적용하기에는 부적합하다고 판단된다.

• Journal of The Korean Association For Science Education
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• v.30 no.2
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• pp.181-191
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• 2010

In this study, we have come to classify experiment illustrations inserted in chemistry I textbook according to types (photographs and pictures) and roles (instruments, reagents, process and results). Also, in the case of person in illustrations not following the safety rules or mishandling instruments in the experimental process, we have come to define it as an 'error'. The problem is that, students tend to accept these errors unquestioningly and as a result, during the experiments, safety concerns can arise. Besides, the mishandling of instruments can lead to the wrong result of experiments. These errors are thought to be caused in the process of making illustrations. Therefore, to minimize errors in the illustrations for the experiments, experts specializing in illustrations should participate in the actual experimental illustrations process.

• Transactions of the Korean Society of Mechanical Engineers
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• v.10 no.1
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• pp.102-109
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• 1986

Based on the Hartenberg-Denavit symbolic equation, which is one of equations for the kinematic analysis of three dimensional (3-D) linkage, a generalized kinematic motion equation is derived utilizing Euler angles and employing the coordinates transformation. The derived equation can feasibly be used for the motion analysis of any type of 3-D linkages as well as 2-D ones. In order to simulate the general motion of 3-D linkgages on digital computer, the generalized equation is programmed through the process of numerical analysis after converting the equation to the type of Newton-Raphson formula and denoting it in matrix form. The feasibility of theoretically derived equation is experimentally proved by comparing the results from the computer with those from experimental setup of three differrent but generally empolyed 3-D linkages.

• Journal of the Korea Concrete Institute
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• v.18 no.5 s.95
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• pp.639-648
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• 2006

A shear experiment of one-way monotonic loading was carried out with the shear span ratio as the main experimental variable for reinforced concrete beam. Using the finite element analysis as the experimental analysis tool and the analysis method to compute the shear resistance of small shear span ratio, a new macro-model composed of crooked main strut and sub strut is proposed in consideration of the effect of bond action between re-bar and concrete based on the experimental result. The experimental finding affirmed the validity of the proposed macro-model when the shear span ratio was at or below 0.75 and confirmed that the experimental result was the most consistent with the computed analysis result when the effective factor of concrete compressive strength was set at 0.75.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.287-288
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• 2016

기존 자가발전 운동기구의 경우, 가변저항을 사용하여 운동강도를 조절하기 때문에 Generator에서 생성된 에너지가 모두 소모되는 문제점이 있다. 또한 계통연계형 자가발전 운동기구의 경우에는 에너지 회수는 가능하지만 운동 강도 조절이 불가능한 단점이 존재한다. 따라서 본 논문에서는 계통연계를 통해 에너지 회수가 가능하고, 운동 강도 조절이 가능한 자가발전 운동기구용 DC/DC 컨버터를 제안한다. 제안회로는 가변저항을 사용하지 않고 입력임피던스를 통해 운동 강도를 조절하기 때문에 높은 에너지를 생성할 수 있고 계통연계를 통해 에너지 회수도 가능한 장점이 있다. 본 논문에서는 제안된 회로의 이론적 특성을 분석하고 모의실험을 통해 확인하였으며, 계통연계형 자가발전 운동기구에 적용하여 실험을 통해 우수성을 검증하였다.