• 한국과학교육학회지
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• 제23권6호
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• pp.609-616
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• 2003

본 연구에서는 3단계의 체계적인 그림 그리기를 활용한 수업이 학업 성취도, 개념, 학습 동기, 수업 참여도에 대한 인식, 과학 수업에 대한 즐거움에 미치는 효과를 조사 하였다. 서울시 남녀 공학 중학교 1학년 두 학급을 통제 집단과 처치 집단으로 선정하고, '물질의 세 가지 상태'와 '분자의 운동' 단원에 대하여 총 8차시 동안 수업을 실시하였다. 이원 공변량 분석 결과, 처치 집단의 학업 성취도, 개념, 학습 동기, 과학 수업에 대한 즐거움 검사 점수가 통제 집단에 비하여 유의미하게 높았다. 수업 창여도에 대한 인식에서는 두 집단 간 차이가 없었다.

• Macromolecular Research
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• 제8권6호
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• pp.292-297
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• 2000

The theoretical synthesis of the isotactic and syndiotactic poly(methyl methacrylate) were carried out as a model for real polymerization reactions following the normal chain reaction processes by repeating the uniform localization of wave functions with inclusion of the interaction between the end group of the cluster and an attaching molecule by the elongation method, and then, the calculated value was compared with the usual PM$_3$ calculation. The results revealed that a reaction of cluster with monomer molecules has made it possible to calculate the electronic structure and total energy of polymer with nearly infinite length and a matrix of constant dimension. The isotactic poly(methyl methacrylate) is more stable than syndiotactic one. The same tendency have been found between the experimentally measured properties and a calculated total energy to explain the chain motion in isotatic and syndiotactic poly(methyl methacrylate).

• Bulletin of the Korean Chemical Society
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• 제12권4호
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• pp.397-403
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• 1991

Dissociation of a highly excited diatomic molecule in the Ar + Ar…$O_2$ and Ar + $O_2$ collisions is studied using trajectory dynamics procedures in the collision energy range of 0.050 to 1.0 eV. Between 0.050 and 0.2 eV, dissociation probabilities are very large for the complexed system compared to the uncomplexed system. This efficient dissociation of $O_2$ in Ar…$O_2$ is attributed to the ready flow of energy from the incident atom to the large-amplitude vibrational motion of the excited O2 via the van der Waals bond. Thermal-averaged dissociation probabilites of $O_2$ in Ar + Ar…$O_2$ near room temperature are nearly two orders of magnitude larger than those of $O_2$ in Ar + $O_2$.

• 멤브레인
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• 제29권1호
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• pp.37-43
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• 2019

본 연구에서는 분자동역학에서 원자의 움직임을 정의하는 가장 중요한 요소인 force-field가 실제 고분자 및 기체 분자의 움직임에 어떠한 영향을 주는지 알아보고자 하였다. Repeat unit과 고분자 구조는 본 연구에서 사용된 5종의 force-field 에서 모두 정상적으로 작용을 하였고, 최종 고분자 3D 모델에서 고분자 linear chain의 분포에서도 큰 차이를 보이지 않았다. 그러나 실제 기체 분자의 움직임은 매우 다른 경향을 나타내었으며, 이는 같은 functional form을 사용하는 COMPASS와 pcff 에서도 관찰되었다. 따라서 동일한 구조라고 하더라도 기체 분자의 운동은 시간에 따라 지속적으로 force-field의 영향 하에서 움직이기 때문에, 고분자 linear chain과 같은 거대 분자에 비하여 그 영향을 훨씬 크게 받는다는 것을 알 수 있으며, 결론적으로 서로 다른 force-field의 사용 시에는 결과 비교에 있어서도 매우 신중을 기해야 할 것이다.

• Journal of Korean Society for Atmospheric Environment
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• 제15권E호
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• pp.65-71
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• 1999

The log-normal size distribution theories developed recently for aerosol coagulation are reviewed. The analytical solutiosn to Brownian coagulation developed recently for various particle size regimes are reviewed. In order to describe the evolution of the size distribution of a coagulating aerosol over the entire size range, the analytical solutions developed individually for the free-molecule regime, the transition regime, the nearcontinuum regime, and the continuum regime have been combined. The work described here represents the first analytical solution to the aerosol coagulation problem covering the entire particle size range.

• 대한기계학회논문집A
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• 제24권4호
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• pp.830-838
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• 2000

The paper addresses an application of molecular dynamics technique for fracture mechanics. Molecular dynamics simulation is an atomistic approach, while typical numerical methods such as finite element methods are macroscopic. Using the potential functions, which express the energy of a molecular system, a virtual specimen with molecules is set up and the trajectory of every molecule can be calculated by Newton's equation of motion. Several three-dimensional models with various types of cracks are considered. The stress intensity factors, the sizes of plastic zone as well as the dislocation emission are sought to be compared with the analytical solutions, which result in good agreement.

• Bulletin of the Korean Chemical Society
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• 제34권12호
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• pp.3800-3804
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• 2013

In this study, molecular dynamics simulations of SPC/E (extended simple point charge) model have been carried out in the canonical NVT ensemble over the range of temperatures 300 to 550 K with and without Ewald summation. The quaternion method was used for the rotational motion of the rigid water molecule. Radial distribution functions $g_{OO}(r)$, $g_{OH}(r)$, and $g_{HH}(r)$ and self-diffusion coefficients D for SPC/E water were determined at 300-550 K and compared to experimental data. The temperature dependence on the structural and diffusion properties of SPC/E water was discussed.

• 대한화학회지
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• 제53권6호
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• pp.784-792
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• 2009

본 연구는 과학 교사들의 과학과 교수 . 학습 설계 시 도움이 되는 자료를 제공하기 위하여 각 시-도 교수학습지원센터와 서울특별시과학전시관 홈페이지에 게재되어 있는 교수-학습 과정안에 나타나는 교육과정 위계 부적합 사례를 조사하였다. 교육과정 위계 부적합 사례는 7학년 ‘물질의 세 가지 상태’ 단원에 한정하였으며, 분석에 사용한 내용 요소는 물질의 상태 변화, 분자, 분자 모형이었다. 그 결과 교육과정 위계 부적합 사례에 해당하는 내용 요소는 ‘물질의 상태 변화’에서는 플라즈마, 상평형, 눈이 생기는 현상, 물의 특이성, 결정성과 비결정성 고체의 분류, 열에너지, 물리 변화 등 7종류였으며, ‘분자 모형’에서는 분자 운동, 밀도가 발견되었다. 그리고 ‘분자’에서는 교육과정 위계 부적합 사례가 발견되지 않았다.

• 한국초등과학교육학회지:초등과학교육
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• 제19권1호
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• pp.101-112
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• 2000

The purpose of this study was to develop the modular multimedia instructional materials emphasizing the particulate nature on the realm of matter in elementary science classes. Features of the material are as follows: 1 To be in focus on particulate model named 'phenomenal magnifying glasses' in order to change the student's belief system of continuous matter into the belief system of particulate matter . The 'phenomenal magnifying glasses' is a new instructional strategy designed to change into the view of particulate matter through facilitating the reflective thinking resulted from the simultaneous consideration of experimental phenomena(macroscopic world) and particulate model(microscopic world). 2. To introduce modular system into the instructional materials, which was consisted of 14 subunits according to the sequential instruction unit of 'molecule and molecular motion'. Each subunit was composed of 5 types of modules(module 1: motivation, module 2: experimental result, module 3: discussion, module 4: phenomenal magnifying glasses, module 5: related experiment) 3. The multimedia program was composed of 36 kinds of experimental animation and 59 kinds of computer animation materials combined with text resources, photographic materials and sounds.

• 센서학회지
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• 제19권6호
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• pp.403-420
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• 2010

Nano and micro structure-based biosensors are promising tool for label-free detection of biomolecular interactions with great accuracy. This review gives a brief survey on nano and micro platforms to sense a variety of analytes such as DNA, proteins and viruses. Among incredible nano and micro structure for bio-analytical applications, the scope of this paper will be limited to micro and nano resonators and nanowire field-effect transistors. Nanomechanical motion of the resonators transducers biological information to readable signals. They are commonly combined with an optical, capacitive or piezo-resistive detection systems. Binding of target molecule to the modified surface of nanowire modulates the current of the nanowire through electrical field-effect. Both detection methods have advantages of label-free, real-time and high sensitive detection. These structures can be extended to fabricate array-type sensors for multiplexed detection and high-throughput analysis. The biosensors based on these structures will be applied to lab-on-a-chip platforms and point-of-care diagnostics. Basic concepts including detection mechanisms and trends in their fields will be covered in this review.