• Membrane and Water Treatment
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• 제11권4호
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• pp.237-245
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• 2020

The effects of the mixed two solvents, Dimethylacetamide (DMAc) and Dimethylformamide (DMF), and Polyethylene glycol (PEG) and Polyvinylpyrrolidone (PVP) as additives on performance of Polyvinylidene fluoride (PVDF) membranes were studied. Initially, PEG200 was used as a primary additive at fixed percentage of 5% wt. PVP was then blended with PEG200 in different concentrations. PVDF and DMAc were used as polymer and solvent in the casting solutions, respectively. To control the diffusion rate of PVP in the presence of PEG200 and PVP blend, mixtures of DMAc and DMF were used as the mixed solvent in the casting solutions. Asymmetric PVDF membranes were prepared via phase inversion process in a water bath and the effects of two additives and two solvents on the membrane morphology, pure water flux (PWF), hydrophilicity and rejection (R) were investigated. Attenuated Total Reflection Fourier Transform Infrared Spectra (ATR-FTIR) analysis was used to show the residual PVP on the surface of the membranes. Atomic Force Microscopy (AFM) was utilized to determine roughness of membrane surface. The use of mixed solvents in the casting solution resulted in reduction of PVP diffusion rate and increment of PEG diffusion rate. Eventually, PWF and R values reduced, while porosity and hydrophilicity increased.

• 한국가구학회지
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• 제19권5호
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• pp.341-349
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• 2008

This study intends to analyze the importance of design on the basis of the children' emotion, by instancing the child-oriented furniture that contributes to the healthy growing and emotion-development of children. This means the reflection of the will trying to see the main point of design for the child-oriented furniture and it's possibility from another new standpoint. It will be understood how far the furniture influences the children and for that the furniture among others for the preschool children having playing & leaning functions is taken as an object of the study. The scope of study is the child-oriented furniture having playing & learning functions that has been presented for displaying as well as for a commercial use, since 2005. The attempt to find objective factors working positively for the emotion- & behavior development of children through seeking a new design of the child-oriented furniture for playing & learning is for emphasizing the importance of the emotional function, not only the primary function of furniture, at designing the child-oriented furniture. The combination between applications of the specialized material for child education & studies, therefore, has to be handled more importantly. The child-oriented furniture for playing & leaning that stimulates a healthy growing of child not only physically, also emotionally should be constantly and more deeply specialized on child education and design aspects.

• 센서학회지
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• 제13권2호
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• pp.85-89
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• 2004

This paper represents the development of high sensitivity photo-sensor for the fluorescence detection in the integrated biological analysis system. The finger-type PIN photodiodes were fabricated as the photo-sensor, and had a high sensitivity ($I_{light}/I_{dark}$ = 8720). The interference filter consisted of $TiO_{2}$ and $SiO_{2}$ was directly deposited on the photodiodes. Deposited filter with 95.5% reflection under 532 nm and 98% transmission over 580 nm exceedingly decreased the magnitude of background signal in the detection. The PDMS micro-fluidic channels are bonded on the photodiode by $O_{2}$ plasma treatment. The detection current was proportional to two primary parameters (light intensity, concentration), and the on-chip detection system could detect fluorescence signals down to 100 nM concentration (LOD = Limit of detection of rhodamine).

• 정보교육학회논문지
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• 제6권3호
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• pp.247-255
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• 2002

정보 통신 기술 활용의 중요성이 부각되고 이를 위한 소양교육이 초등학교 1학년부터 도입되었다. 본 연구는 정보 통신 기술 소양교육의 내용을 분석하고 학습에서의 개인차를 줄일 수 있는 방법을 모색하여 학습프로그램을 설계하고 구현한다. 초등학교 저학년에서 학습할 가장 기본적인 내용을 선정하며, 코스웨어를 설계함에 있어서, 학습내용의 완전습득을 위하여 형성평가와 피드백을 이용하는 완전학습 전략을 도입한다. 또한 멀티미디어를 사용하여 학습내용을 다양하게 제시함으로써 학습자의 인지활동을 도울 수 있도록 설계된다. 이를 충실히 반영하여, 학습자가 자신의 학습 속도와 흥미 및 학습수준에 맞추어 개별화 학습을 할 수 있는 코스웨어로 구현한다.

• 한국수학교육학회지시리즈C:초등수학교육
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• 제10권2호
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• pp.77-110
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• 2007

This study attempted to investigate how to students show high-level mathematical thinking in math classes. This paper describes how to setup the task for lead to a high - level of thinking out students and what efforts are required while a teacher tried to maintaining students's high-level cognition during the tasks implemented. The researcher as teacher analyzed the tasks of length measurement unit in 2-Ga elementary math textbooks, modified and created math tasks demanded students' high-level cognition, made instruction plans, and implemented those tasks maintaining the levels of cognitive demand of tasks. After that, the researcher reflected and analyzed the levels of cognitive demand of tasks of instruction and factors that cause to change intended high-level cognitive demand. After reflection, second roof of action research was conducted to 2-Na length measurement unit. This paper includes those results and reflections of practitioner.

• 한국수학교육학회지시리즈C:초등수학교육
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• 제6권1호
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• pp.41-54
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• 2002

The purpose of this study is to find out what mathematical situation means, how to pose a meaningful situation and how situation-centered teaching could be done. The obtained informations will help learners to improve their math abilities. A survey was done to investigate teachers' perception on teaching-learning in mathematics by elementary teachers. The result showed that students had to find solutions of the textbook problems accurately in the math classes, calculated many problems for the class time and disliked mathematics. We define mathematical situation. It is artificially scene that emphasize the process of learners doing mathematizing from physical world to identical world. When teacher poses and expresses mathematical situation, learners know mathematical concepts through the process of mathematizing in the mathematical situation. Mathematical situation contains many concepts and happens in real life. Learners act with real things or models in the mathematical situation. Mathematical situation can be posed by 5 steps(learners' environment investigation step, mathematical knowledge investigation step, mathematical situation development step, adaption step and reflection step). Situation-centered teaching enhances mathematical connections, arises learners' interest and develops the ability of doing mathematics. Therefore teachers have to reform textbook based on connections of mathematics, other subject and real life, math curriculum, learners' level, learners' experience, learners' interest and so on.

• 한국재료학회지
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• 제4권5호
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• pp.516-523
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• 1994

이논문에서는 metal organic chemical vapor deposition(MOCVD)에 의해서 성장된 InGaAsP/InP이종접합구조의 격자부정합이 Photoluminescence(PL)효율에 미치는 영향을 연구하였다. 격자부정합은 (400)과 {511} x-ray reflection을 통해 측정하였고, 부정합 전위의 유무는 x-ray to-pography와 PL imaging을 통해 확인했다. PL강도 측정결과, 상대적으로 높은 PL강도는 탄성적으로 스트레인을 받은 시료에, 낮은 PL강도는 전위로 인해 비탄성적으로 변형된 시료에서 얻어졌다. 성장온도에서 격자정합된 시료의 PL효율이 실온에서 가장 높은 것을 알 수 있었다. PL강도와 X-ray반치폭과 관계에서, 시료의 광전자 특성이 구조적 특성과 밀접하게 연관됨을 알 수 있었다.

• International Journal of Computer Science & Network Security
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• 제21권6호
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• pp.151-155
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• 2021

The article is based on a model, in the context of which there are two fundamental building blocks of basic library skills and skills in the use of information technology. The former are formed within the framework of educational programs for users of academic libraries, the latter are formed within the framework of initiatives such as the European Computer Driving License. Between the basic and the highest levels of the concept of "information literacy" there are seven heading skills and attributes, the repeated practice of which leads from the position of a competent user to an expert level of reflection and critical awareness of information as an intellectual resource. Freshmen will likely be at the beginning of the arrow, probably practicing only the first four skills, while graduate students and young scientists will be closer to the end and will use seven skills.

• 한국항만학회지
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• 제12권1호
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• pp.75-86
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• 1998

To design a coastal structure in the nearshore region, engineers must have means to estimate wave climate. Waves, approaching the surf zone from offshore, experience changes caused by combined effects of bathymetric variations, interference of man-made structure, and nonlinear interactions among wave trains. This paper has attempted to find out the effects of two of the more subtle phenomena involving nonlinear shallow water waves, amplitude dispersion and secondary wave generation. Boussinesq-type equations can be used to model the nonlinear transformation of surface waves in shallow water due to effect of shoaling, refraction, diffraction, and reflection. In this paper, generalized Boussinesq equations under the complex bottom condition is derived using the depth averaged velocity with the series expansion of the velocity potential as a product of powers of the depth of flow. A time stepping finite difference method is used to solve the derived equation. Numerical results are compared to hydraulic model results. The result with the non-linear dispersive wave equation can describe an interesting transformation a sinusoidal wave to one with a cnoidal aspect of a rapid degradation into modulated high frequency waves and transient secondary waves in an intermediate region. The amplitude dispersion of the primary wave crest results in a convex wave front after passing through the shoal and the secondary waves generated by the shoal diffracted in a radial manner into surrounding waters.

• 의학교육논단
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• 제26권1호
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• pp.55-69
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• 2024

Amid the increasing interest in medical humanities education, this study developed a medical humanities course that utilized design thinking to foster creative thinking, problem-solving, and collaboration skills that pre-medical students should possess. The course's efficacy was assessed by evaluating improvements in core design thinking skills. The present study was conducted among 83 first-year medical students after planning and implementing a design thinking course. The reflection journals written by students along the course of the class were examined using the template analysis technique to evaluate the effectiveness of the class. The study's primary findings showed the successful development of step-by-step medical humanities education content utilizing design thinking and its practical implementation in a class. Moreover, the course improved students' core design thinking skills effectively, and in a balanced way. These results illustrate the effective application of design thinking in medical school through a medical humanities course. These findings indicate that a medical humanities course can help medical students showcase their abilities to collaborate and solve problems in the real world. This paper suggests the need for further research to develop a curriculum that integrates design thinking and investigate the relationship between medical students' core competencies and design thinking-based courses.