• Journal of the Korean Chemical Society
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• v.52 no.5
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• pp.550-560
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• 2008

• Journal of the Korean Chemical Society
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• v.49 no.4
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• pp.407-416
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• 2005

• Journal of the Korean earth science society
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• v.29 no.1
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• pp.91-97
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• 2008

The purpose of this study is to explore high school students' understanding of the distinction between scientific theories and scientific laws. Understanding of the distinction between these two concepts, which belong to the nature of science, has been receiving little attention. We surveyed thirty-two students from a local high school with three-part, open-ended questionnaire. The result revealed that these students shared common misconceptions such as 'scientific theories are unproven, scientific laws are proven and absolute', and 'if a theory is proven with enough evidence, it becomes a law'. Moreover, students tend to regard earth science less sophisticated than physical science, because they recognize a lot of its theories to be unproven in their view. It is indicated further that teaching the difference between scientific theories and laws explicitly could help students possess more appropriate view toward earth science.

• Journal of the Korean Chemical Society
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• v.54 no.5
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• pp.611-620
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• 2010

The purpose of this study was to explore the structure and content of chemistry teacher's explanations from the perspective of 'persuasion'. Especially, this study was to explore how the argument structure and the conceptual change constructs in chemistry teachers' explanations were established and interacted. Data were collected from chemistryI classes considering the gas unit which includes kinetic theory of gas, Graham's law, Boyle's law, and Charles' law. The classes were vediotaped and transcribed. The transcriptions were analyzed with Toulmin's argument frame and the two constructs of conceptual change model; the conceptual ecology and the status of a conception to interpret the persuasive structure and content of the teacher's explanations. As the results of this study, four explanatory discourses which show various persuasive explanations in chemistry classes. Based on this results, discussion and implications for effective teachers' explanations in chemistry classes were presented.

• Journal of the Korean Chemical Society
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• v.56 no.1
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• pp.144-158
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• 2012

In this study, science teachers' and students' perceptions were searched on lectures and experiment of law of definite proportion in middle school science classes. For this study, the three teachers' lessons were observed and recorded, following interviews related to teachers' perceptions on the lessons and experiments. Also, We analyzed students' science scores, cognitive levels, science attitude, experimental reports, etc. According to the results, the three teachers had different focuses in the lectures. Chemistry teachers accentuated calculation of proportions and application rather than basic conceptions. But the students could not understand basic conceptions properly. The teachers spend long time to explain experimental procedures by assuming a low performance level of students in experimental classes. And the teachers had negative perceptions about error of results. The students could not understand the experiment results well, tried to manipulate data artificially, and had negative perceptions about error of results like the teachers. We suggested that these problems might be solved by changing teachers' perceptions on school science lectures and experiments.

• Journal of the Korean Chemical Society
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• v.37 no.8
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• pp.753-756
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• 1993

Studies on the molecular interactions of dimethylsulfoxide (DMSO) with water and/or some alkanols were carried out by vapor pressure osmometry at 40$^{\circ}C$. Negative deviation from Raoult's law was observed for the DMSO-water, methanol, ethanol, 1-propanol, 2-propanol, and 2-methyl-1-propanol systems, whereas positive deviation from Raoult's law was observed for the DMSO-1-butanol and 1-pentanol systems. The results were interpreted in terms of molecular interactions between unlike molecules, and of self-association of DMSO molecules, respectively. Measured chemical shift of hydroxyl proton of the solvents also supported the results.

• Journal of the Korean GEO-environmental Society
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• v.4 no.1
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• pp.5-10
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• 2003

The solids and the fluids in porous media have a relative velocity to each other. Due to physically and chemically different material properties and their relative velocity, the behavior of saturated porous media is extremely complicated. Thus, in order to describe and clarify the deformation behavior of saturated porous media, constitutive models for deformation of porous media coupling several effects need to be developed in frame of Arbitrary Lagrangian Eulerian(ALE) description. The aim of ALE formulations is to maximize the advantages of Lagrangian and Eulerian elements, and to minimize the disadvantages. Therefore, this method is appropriate for the analysis of porous media which are considered for the behavior of the solids and the fluids. For this reason, mass balance equations for saturated porous media are derived here in ALE description frames. ALE formulations of mass conservation for the solid phase and the fluid phase are expressed. Then, linear momentum balance equation for porous media as multiphase media is expressed.

• Journal of the Korean Chemical Society
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• v.50 no.5
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• pp.374-384
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• 2006

this study, the teaching methods of three science teachers for lead-iodide precipitation reaction experiment were compared. The difference of 9th grade students' understanding was searched according to the science teachers teaching styles, also. Among the three teachers, Teacher A taught students based on the science textbook and allowed students to think themselves and to get out conclusion by the experiment. Teacher B and Teacher C gave students a lot of explanations related to interpretation of the experiment. The percentage of no response on the experiment report of Teacher A was higher than those of Teacher B and Teacher C. But the students of Teacher B and Teacher C tended to have limited thoughts because of the teachers explanations. In spite of the difference, it was common phenomenon that few students understood concepts through the experiment. A lot of students were interested in the experiment, but it was hard to understand Law of definite proportions according to the experiment.

• Applied Chemistry for Engineering
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• v.17 no.5
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• pp.443-450
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• 2006

Micelles have been used in many applications. In these applications it is of prime importance to know how the critical micelle concentration (CMC), above which the micelles are formed, depends on temperature. Up to date polynomial functions of temperature have been used to describe temperature dependence of CMC. In this article it is shown that such polynomials are inadequate tools to express thermal behavior of CMC. Hence, new equations of CMC(T) have been derived on the basis of rigorous thermodynamic equations and experimental observations on CMCs. The new equations fit CMC data excellently, and further they lead to a power law for the CMC. The exponent of the power-law expression is 2 irrespective of surfactant systems, which points to the generality of newly found equations.

• Korean Architects
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• s.566
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• pp.92-97
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• 2016

지난 두 회에 걸쳐 흔히 사람들이 이야기하는 파라메트릭 디자인의 전형에 가까우며 현재의 건축 및 시공 기술로 충분히 구현이 가능한 두 예를 살펴보았습니다. 조금 지루하다고 여기셨을 분들을 위해 앞으로 몇 회간은 시뮬레이션(simulation)에 대해 이야기를 해 볼까 합니다. 시뮬레이션은 단어가 의미하는 것처럼 실제의 현상을 모방하는 과정을 의미하며 이미 많은 분야에서 다양한 목적을 위해 사용되고 있습니다. 쉽게 머릿속에 떠오르는 시뮬레이션은 아마도 영화나 컴퓨터 게임에서 자연현상이나 물리적 법칙에 의한 사물의 거동 등을 본뜨고자 하는 목적의 특수효과를 위한 시뮬레이션, 과학자들이 자연의 현상의 이해 및 예측, 혹은 가설의 검증 등을 위해 사용하는 시뮬레이션, 엔지니어들이 물체의 물리적 화학적 거동을 시험해 보기 위해 사용하는 시뮬레이션 등이 아닐까 생각합니다. 시뮬레이션은 기본적으로 어떠한 현상에 대한 이해를 바탕으로 그러한 현상을 만들어 내는 법칙을 찾아내어 이를 디지털 모델화 하여야 합니다. 몇 회 전에 말씀드렸던 것처럼, 실험에 실험을 거듭하여 가장 영향력이 큰 변수를 찾아내고 미처 이해하지 못한 변수들을 보강하기 위해 도입하는 상수 등으로 이러한 과학적인 법칙을 도출하게 됩니다. 싸고 막강한 성능의 컴퓨터 및 데이터 저장방법 등을 등에 업은 빅 데이터(Big Data)를 통한 방법론이 이미 통계 및 확률의 분야에서 전통적인 알고리듬에 바탕을 둔 시뮬레이션에 우위를 점하고 있는 상황이긴 하지만, 개인적인 생각으로는 항상 다른 분야에 비해 기술적으로 한발 뒤쳐질 수밖에 없는 건축의 보수적인 속성 및 좀 더 많은 것에 대해 컨트롤을 하고 싶어 하는 많은 건축인들의 애착 등을 고려해 보았을 때 건축에서의 시뮬레이션이라는 영역은 아직도 알아야할 가치가 많다고 생각됩니다.