중학교 과학교육에서 천체운동의 개념형성학습에 관한 연구

김순,강용희,안병호,윤일희,정원우 慶北大學校 師範大學 科學敎育硏究所 1999 科學敎育硏究誌 Vol.23 No.-

We consider the effect of conceptual learning through exploratory activities concerning the concepts of motion of celestial bodies in the middle school science class. We are also trying to show an improved way of teaching for the effective conceptual learning. To measure the effect of conceptual learning, we prepared a questionnaire with 17 test items concerning basic concepts of motion of earth and planets. The test scores for the conceptual learning group was significantly higher than those of the conventional learning group. Educational implications of the planned conceptual learning through exploratory activities are discussed.

레드 저마네이트 단결정의 초전성 및 자발분극 변화

김일원 울산대학교 1987 연구논문집 Vol.18 No.2

실온에서 부터 Curie 온도까지 레드 저마네이트(Pb??Ge₃O??) 단결정의 초전계수를 이론식으로 부터 구한 값과 실험값을 비교하였다. 실온에서 레드 저마네이트 단결정의 초전계수 값은 2.5×10??C/m²℃이었고, 자발분극은 4.6μC/㎠이었다. 레드 저마네이트 단결정의 온도변화에 따른 초전계수는 Gibbs 자유에너지 이론과 이력곡선으로 부터 계산된 이론값과 실험값이 잘 일치하였다. The pyroelectirc coefficients of Pb??Ge₃O?? single crystals were obtained from room temperature to Curie temperature. At room temperature, the pyroelectirc coefficient and spontaneous polarization of Pb??Ge₃O?? single crystals were 2.5×10?? C/m²℃ and 4.6μC/㎠, respectively. The temperature dependency of the pyroelectric coefficient of Pb??Ge₃O?? single crystal was in good agreement with the results calculated from hysteresis loop and the Gibbs free energy theory.

비글개에서 분만 후 자궁수복의 연속적 초음파상

손형원, 김홍석, 김형진, 김일화, 이기창, 이청산, 강현구 충북대학교 동물의학연구소 2006 Journal of Biomedical and Translational Research Vol.7 No.2

본문참고

폴리머 에멀젼 혼입에 의한 시멘트의 모르타르의 물성 변화 : Addition of EVAc Emulsion EVAc 에멀젼 첨가

김창은,김기일,김원기 연세대학교 산업기술연구소 1989 논문집 Vol.21 No.1

시멘트 모르타르에 EVAc 에멀젼 및 계면활성제(Sodium Dodecylbenzenesulfonate)를 첨가하여 압축강도, 흡수율, 화학적 저항성, 수화발열속도, 전자현미경 등으로 그 물성을 관찰하였다. EVAc를 시멘트에 첨가할 경우 5-15wt%, SDBF는 0.03wt%를 첨가하고 혼수량을 flow value로써 기준하는 것이 최적조건임을 알 수 있었다. 그리고 EVAc emulsion을 첨가하므로서 혼수량 및 흡수율의 감소효과를 거둘수가 있었으며 또한 화학적 저항성도 증가되었다. EVAc emulsion을 과다 첨가할 경우에는 강도가 저하하나, 여기에 계면활성제(Sodium Dodecylbenzenesulfonate)를 가하면 강도가 증가하였으며, 한편 수화 속도는 지연되었다. Properties of the cement mortar which mixed with EVAc emulsion and surfactant(Sodium Dodecylbenzene Sulfonate;SDBF) have been investigated by considering conpressive strength, water absorption, corrosion resistance, hydration heat evolution rate, and SEM. As a result, proper conditions were in the case of adding 5-15 wt% EVAc and 0.03wt% SDBF into cement mortar and determining water consistency by flow value. EVAc addition resulted in decreasing water consistency and water absorption, and increasing corrosion resistance of cement mortar. Strength of cement mortar decreased by adding excess EVAc. But strangth was increased and hydration rate was slowed by SDBF addition.

LinbO₃단결정의 가열현상에 따른 자발분극 변화 및 초전계수

김갑진,김일원 울산대학교 1987 연구논문집 Vol.18 No.2

LiNbO₃단결정의 자발분극 변화량 △Ps와 초전계수 ?????를 25℃∼300℃ 온도 영역에서 측정하였다. 전극은 시료의 양극면에 silver paste를 사용하여 0.15㎠ 되게 하였다. 일정한 stress상태에서 시료의 온도를 연속적으로 변화 시켰다. 온도변화에 따른 자발분극 변화량은 op amp를 이용하여 결정극면에 나타나는 전하를 콘덴서에 축적하여 측정 하였다. 결정극면에 전기장이 없을 때 자발분극 변화량은 연속적인 온도의 함수로 측정하였다. 측정한 초전계수와 계산한 secondary 초전계수를 비교한 결과 LiNbO₃단결정의 초전성은 primary 초전현상에 기인하였다. 온도영역 100℃∼150℃ 사이에서 congruent한 c-plate시료에 나타나는 초전성의 불규칙한 변화는 분역들의 재정돈에 기인함이 확인되었다. 25℃∼300℃가지 LiNbO₃단결정의 자발분극 변화량은 2,858×10??C/㎠ 이었고 50℃에서 초전계수는 6.32×10??C/㎠℃ 이였다. Measurements of spontaneous polarization, Ps, and pyroelectric coefficient, dPs/dΘ, of LiNbo₃have been made over the temperature range from 25℃ to 300℃. Several crystals of typical surface area of 0.15㎠ were electroded with silver paste on the faces normal to the polar axis. The crystals were mounted in an unclamped manner and the temperature was varied continuously from 25℃ to 300℃. The change of spontaneous polarization as a function of temperature was obtained by integration the charge which appear on the polar faces of the crystal with an operational amplifier. With this arrangement the field across the crystal is essentially zero at all times, and the spontaneous polarization change can be recorded continuously as a function of temperature. After evaluating and comparing data, it becomes evident that the major pyroelectric properties of LiNbO₃, particulary in the temperature range, 25℃-300℃, belong to primary effect. The anomalous change of pyroelectric effect in LiNbO₃as grown crystal of congruent c-plate in the temperature region between 100℃-150℃ was due to the domain rearrangements. The change of spontaneous polarization is found to be 2.858×10??C/㎠ at 25℃-300℃ and pyroelectric coefficient for the LiNbo₃is measure to be 6.32×10??C/㎠℃ at 50℃.

Ramsay-Hunt Syndrome 환자 1례에 대한 증례보고

김일수,송인선,유호상,손원택,오민석,송태원 대전대학교 한방병원 2001 惠和醫學 Vol.10 No.1

Ramsey-Hunt Syndrome occurs when herpes zoster after the facial nerve. It causes vesicular eruption of the pinna, external auditory meaturs and ear drum, severe otalgia with associated facial paralysis and vertigo. We experienced a case of Ramsay Hunt syndrome and managed it with oriental medicine's teatment and therapy of western medicine

加味行滯湯 合 六味地黃湯이 水銀(Hg)에 의한 家兎 肝組織損傷에 미치는 影響

金元一,金宇煥 동의대학교 한의학연구소 1998 동의한의연구 Vol.2 No.-

This study was carried out to determine whether Kamihaengche-Tang plus Yukmijihwang-Tang(KCYH) exerts the protective effect against Hg-induced white rabbit liver cell injury. Cell injury was estimated by measuring alanine aminotransferase (ALT) release, and lipid peroxidation was estimated by measuring malondialdehyde, a product of lipid peroxidation, in rabbit liver slices. Hg increased ALT release in dose-dependent manner over the range of 0.1-1 mM concentrations. Similarly, the drug also increased lipid peroxidation, indicating that Hg-induced liver cell injury was attributed to lipid peroxidation. When 0.5% KCYH was added to incubation solution, the cell injury and lipid peroxidation induced by Hg were markedly prevented. When liver tissues were treated with 0.5 mM Hg, cellular glutathione content significantly decreased. The addition of 0.5% KCYH to the medium increased, but not statistically significant, Hg-induced reduction in glutathione content. These results indicate that KCYH exerts the protective effect against Hg-induced liver cell injury, and this effect is attributed ti antioxidant action. However, the precise mechanisms of antioxidant effect of KCYH remain to be defined.

용접공들의 면역능에 관한 연구

이수일,조봉수,김영욱,고광욱,조원근,김영실,강수용,황인경,조병만,김돈균 大韓産業醫學會 1997 대한직업환경의학회지 Vol.9 No.1

The authors examined human immunity indicators such as CD4, CD8, Natural Killer(NK) cell, IgG, IgA, and IgM, and heavy metals such as Pb, Cr, Cd to evaluate the health hazard of welders. We selected total 126 male subjects, 60 welders who had more than 5 year working history as an exposure group, and 66 office workers and medical college students as a control group. This immunity evaluation approach is the first newly designed study that has never been tried in past studies on welder's heath evaluation. And the results were as follows. 1. Total lymphocyte count of peripheral blood was significantly higher in welder group, 2,615±650 ea/㎕ compared with 2,368±681 ea/㎕ in control group(p>0.05). 2. The proportion of CD4, CD8, NK cell in welder group was 37.5±9.4%, 24.0±8.8%, and 21.0±9.5%, respectively, and 35.5±6.5%, 25.0±6.9%, and 19.6±8.8% in control group. CD4 and NK cell were slightly higher, and CD8 was slightly lower in welder group. but there was no statistical significance between two groups(p≥0.05). 3. IgG, IgA, and IgM in welder group were 15.9㎎/㎗, 2.7㎎/㎗ and 1.5㎎/㎗, respectively, and 15.6㎎/㎗, 2.9㎎/㎗ and 1.7㎎/㎗ in control group. There was no statistical significance between two groups(p≥0.05). 4. Blood lead, cadmium and chromium concentrations were 4.2±1.8㎍/㎗, 0.4±0.38㎍/㎗, 1.2±0.6㎍/㎗ in welder group and 3.2±1.7㎍/㎗, 0.44±0.29㎍/㎗, 1.1±0.6㎍/㎗ in control group, respectively, and these value were within normal ranges.

신경회로망을 이용한 이면비드 폭 예측에 관한 연구

정재원,김일수,박창언,김학형,서주환,김인주,심지연 한국공작기계학회 2008 한국공작기계학회 춘계학술대회논문집 Vol.2008 No.-

The development of robotic welding process is a very complex assignment because the system is affected by a number of process parameters which are very difficult to determine or predict in practice. The full automation welding has not yet been achieved partly because the mathematical model for the process parameters of a given welding task is not fully understood and quantified. Several mathematical models to control welding quality, Productivity, micro structure and weld properties in arc welding processed have been studied. However, it is not an easy task to apply them to the various practical situations because the relationship between the process parameters and the bead geometry is non-linear and also they are usually dependent on specific experimental result. Practically, it is difficult, but important to know how to establish a mathematical model that can predict the result of the actual welding process and how to select the optimum welding condition under a certain constraint. In this paper, an attempt has been made to develop an neural network model to predict the back-bead width as a function of key process parameters in the GMA (Gas Metal Arc) welding and to compare the developed models with the experimental results

교사들의 공통과학 실험 · 실습 선호도 조사 분석

정원우,이윤종,강용희,윤일희,이우붕,손종경,김중욱,강동진,권용주 慶北大學校 師範大學 科學敎育硏究所 1999 科學敎育硏究誌 Vol.23 No.-

The purpose of this study is to investigate the status of the experimental and practical education in high school general science. The present status and reasonable management of the experimental and practical education in high school general science were evaluated by the questionaires. To do this, 146 science teachers in Korea are administered questionaires. The frequency of the experimental and practical items in the seven kind of general science text books were investigated. The problems and the reasonable management for experimental and practical education were proposed in this paper.