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On the Development of Microcomputer-Assisted Mathematics Teaching/Learning Method (마이크로 컴퓨터를 이용한 수학 교수.학습법 개발에 관한 연구)

  • Kim Chang Dong;Lee Tae Wuk
    • The Mathematical Education
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    • v.27 no.1
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    • pp.15-23
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    • 1988
  • We are at the onset of a major revolution in education, a revolution unparalleled since the invention of the printing press. The computer will be the instrument of this revolution. Computers and computer application are everywhere these days. Everyone can't avoid the influence of the computer in today's world. The computer is no longer a magical, unfamiliar tool that is used only by researchers or scholars or scientists. The computer helps us do our jobs and even routine tasks more effectively and efficiently. More importantly, it gives us power never before available to solve complex problems. Mathematics instruction in secondary schools is frequently perceived to be more a amendable to the use of computers than are other areas of the school curriculum. This is based on the perception of mathematics as a subject with clearly defined objectives and outcomes that can be reliably measured by devices readily at hand or easily constructed by teachers or researchers. Because of this reason, the first large-scale computerized curriculum projects were in mathematics, and the first educational computer games were mathematics games. And now, the entire mathematics curriculum appears to be the first of the traditional school curriculum areas to be undergoing substantial trasformation because of computers. Recently, many research-Institutes of our country are going to study on computers in orders to use it in mathematics education, but the study is still start ing-step. In order to keep abreast of this trend necessity, and to enhance mathematics teaching/learning which is instructed lecture-based teaching/learning at the present time, this study aims to develop/present practical method of computer-using. This is devided into three methods. 1. Programming teaching/learning method This part is presented the following five types which can teach/learn the mathematical concepts and principle through concise program. (Type 1) Complete a program. (Type 2) Know the given program's content and predict the output. (Type 3) Write a program of the given flow-chart and solve the problem. (Type 4) Make an inference from an error message, find errors and correct them. (Type 5) Investigate complex mathematical fact through program and annotate a program. 2. Problem-solving teaching/learning method solving This part is illustrated how a computer can be used as a tool to help students solve realistic mathematical problems while simultaneously reinforcing their understanding of problem-solving processes. Here, four different problems are presented. For each problem, a four-stage problem-solving model of polya is given: Problem statement, Problem analysis, Computer program, and Looking back/Looking ahead. 3. CAI program teaching/learning method This part is developed/presented courseware of sine theorem section (Mathematics I for high school) in order to avail individualized learning or interactive learning with teacher. (Appendix I, II)

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Classical Art and Digital (고전예술과 디지털)

  • PARK, Youjung
    • Trans-
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    • v.4
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    • pp.1-36
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    • 2018
  • This paper summarizes some of the contents of the 7th International Symposium "Classical Art and Digital" of the Transmedia Institute(TMI), held on October 31, 2017. The purpose of this year's International Symposium was to look back on the genre and the aesthetic history of classical art and to create a place for discourse about the recognition of classical art in the modern digital era. In the first part of the discussion about the duplication of the original and virtual imitation, three presentations on "Visual Image Art and Digital" were introduced. The conclusion of this first discussion is summarized by urging the movement of viewpoint as 'systematic change of the routine aesthetic process'. In the second part on "Performing Arts and Digital", we realize that we need to definitize the 'new directive term system' necessary for the era of digital convergence and performance. In this process we can refer to the need for the emergence of a new aesthetic basis. Two papers in the second part of the paper will introduce the study of 'dance' performance. Some of these studies are reintroduced at the conclusion. The theme of this year's International Symposium can be expected to provide a foothold for the forthcoming second 'Laocoon sculpture argue'. In short, behind the various controversies in the history of aesthetics, this year's conference is concluded with a call for the need to flexibly read the enormous flow of 'art' and 'mental heritage left by art'. It is said that this year's international conferences are presenting the basis of practical and systematic theories for the upcoming fusion media era.

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Removal of Fe Impurities on Silicon Surfaces using Remote Hydrogen Plasma (리모트 수소 플라즈마를 이용한 Si 표면 위의 Fe 불순물 제거)

  • Lee, C.;Park, W.;Jeon, B.Y.;Jeon, H.T.;Ahn, T.H.;Back, J.T.;Shin, K.S.;Lee, D.H.
    • Korean Journal of Materials Research
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    • v.8 no.8
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    • pp.751-756
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    • 1998
  • Effects of remote hydrogen plasma cleaning process parameters on the removal of Fe impurities on Si surfaces and the Fe removal mechanism were investigated. Fe removal efficiency is enhanced with decreasing the plasma exposure time and increasing the rf-power. The optimum plasma exposure time and rf-power are 1 min and 100W. respectively, in the range below 10 min and 100W. Fe removal efficiency is better under lower pressures than higher pressures, and the optimum $\textrm{H}_2$ flow rate was found to be 20 and 60sccm, respectively, under a low and a high pressure. The post-RHP(remote hydrogen plasma) annealing enhanced metallic contaminants removal efficiency, and the highest efficiency was achieved at $600^{\circ}C$. According to the AFM analysis results Si surface roughness was improved by 30-50%, which seems to be due to the removal of particles by the plasma cleaning. Also. Fe impurities removal mechanisms by remote hydrogen plasma are discussed.

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Recent Changes of Sedimentation Rate in Lake Takkobu, Northern Japan, Determined 210Pb Dating (210Pb 연대측정에 의한 일본 타호부호수의 토사퇴적속도 변화 분석)

  • Ahn, Young Sang;An, Ki-Wan;Lee, Kye-Han;Nakamura, Futoshi
    • Journal of Korean Society of Forest Science
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    • v.103 no.1
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    • pp.80-86
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    • 2014
  • $^{210}Pb$ dating was conducted to examine the influence of land use changes in the forest catchment on lake sedimentation. The Kushiro River, into which Lake Takkobu drains under regular flow conditions, contributed to an increased sedimentation rate in sampling point at the lake outflow because turbid water from the Kushiro River flows back into Lake Takkobu during floods. The elevated sediment flux from the catchment dilutes the $^{210}Pb$ concentration in sampling points at the inflow of the Takkobu River and the lake outflow, which causes fluctuations in the $^{210}Pb$ concentrations in sediment cores. The $^{210}Pb$ dating was estimated using the CRS (Constant rate of Supply) model. The dates by the CRS model in Lake Takkobu profiles were in good agreement with the dates by $^{137}Cs$. Sedimentation rates reconstructed for the past 100-150 years suggested that sedimentation rates increased drastically following land use changes. While a natural sedimentation rate of $0.01-0.03g/cm^2/year$ is observed until the 1880s, whereas lake sedimentation accelerated to $0.03-0.09g/cm^2/year$ following land use changes such as deforestation and channelization, between the 1880s and 1940s. In particular, the sedimentation rates have been associated with deforestation, channelization, agricultural development and road construction, since the 1980s, and these rates were about 9-28 times higher than those under natural conditions, leading to accelerated lake shallowing.

Characterization of Microbial Community in the Leachate Associated with the Decomposition of Entombed Pigs

  • Yang, Seung-Hak;Hong, Sun Hwa;Cho, Sung Back;Lim, Joung Soo;Bae, Sung Eun;Ahn, Heekwon;Lee, Eun Young
    • Journal of Microbiology and Biotechnology
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    • v.22 no.10
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    • pp.1330-1335
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    • 2012
  • Foot and mouth disease (FMD) is one of the acute infectious diseases in hoofed and even-toed mammals, including pigs, and it occurs via acute infection by Aphthovirus. When FMD is suspected, animals around the location of origin are typically slaughtered and buried. Other methods such as rendering, composting, and incineration have not been verified in practice in Korea. After the FMD incident, the regular monitoring of the microbial community is required, as microorganisms greatly modify the characteristics of the ecosystem in which they live. This is the result of their metabolic activities causing chemical changes to take place in the surrounding environment. In this study, we investigated changes in the microbial community during a 24 week period with DNA extracts from leachate, formed by the decomposition of buried pigs at a laboratory test site, using denaturing gradient gel electrophoresis (DGGE) with a genomic DNA. Our results revealed that Bacteroides coprosuis, which is common in pig excreta, and Sporanaerobacter acetigenes, which is a sulfur-reduced microbe, were continuously observed. During the early stages (0~2 weeks) of tissue decomposition, Clostridium cochlearium, Fusobacterium ulcerans, and Fusobacterium sp., which are involved in skin decomposition, were also observed. In addition, various microbes such as Turicibacter sanguinis, Clostridium haemolyticum, Bacteroides propionicifaciens, and Comamonas sp. were seen during the later stages (16~24 weeks). In particular, the number of existing microbial species gradually increased during the early stages, including the exponential phase, decreased during the middle stages, and then increased again during the later stages. Therefore, these results indicate that the decomposition of pigs continues for a long period of time and leachate is created continuously during this process. It is known that leachate can easily flow into the neighboring environment, so a long-term management plan is needed in burial locations for FMD-infected animals.

Analysis on the Bluegill Blocking Effects using Bubbles (버블을 이용한 파랑볼우럭 차단 효과 분석)

  • Kang, Joon-Gu;Kim, Jong-Tae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.2
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    • pp.390-397
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    • 2017
  • The introduction of exotic fish species may reduce the number of native fish species and disturb the aquatic ecosystem. Therefore, measures to block and manage fish species are required. Accordingly, a fish species blocking system using bubbles was developed in this study to block exotic fish species. An experimental channel was produced and the possibility of blocking such exotic fish species was evaluated. The bubble generator is a system that produces a bubble curtain by generating air with an air compressor that blocks fish species. Bluegill, which is an exotic fish species in the country, was tested with this generator. The size of bluegill was between 0.10 m and 0.15 m and the depth of water was maintained at 0.70 m. The flow velocity of the experiment channel was classified into 3 levels (0.20 m/s, 0.10 m/s, and 0.05 m/s) considering the natatorial ability of the fish species. The results revealed that 70.07% of bluegill showed movements to swim upstream before applying the bubble, but it is considered that the ascending rate would be higher given that the fish species thinks downstream is a habitat and showed almost no movement. However, when the blocking facility was installed, most fish species showed movements to return to the downstream again by the bubble curtain, indicating a very high blocking effect. In particular, when the generating bubble was terminated, the fish species swam back to the upstream area very soon, so the fish species blocking effect using the bubble was excellent.

A Study on the Angyo Method of Doin Angyo - Whidam's Su-Gi Therapy Based on the Principles of Medical Gigong (도인안교(導引按蹻) 중 안교법(按蹻法)에 대해 - 의료기공 원리에 근거한 휘담식 수기요법)

  • Ahn, Hun Mo;Lee, Jae Heung;Na, Sam Sik
    • Journal of Korean Medical Ki-Gong Academy
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    • v.19 no.1
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    • pp.1-24
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    • 2019
  • Objective : The purpose of this study is to understand a medical Gigong's view of the human body through the analysis of medical Gigong techniques, and to understand the concept and treatment principle of Whidam's Su-Gi therapy as the Angyo(按蹻) Method of Doin Angyo(導引 按蹻) Methods : Among Medical Gigong, Sojucheon practice, Moosim-Gigong Riding stance, Moosim-Gigong Doinbeop, Hwalinsimbang Doinbeop and Donguibogam Jang-Bu Doinbeop were selected to analyze the practice method. The medical Gigong's views of the human body are organized into overviews and pathological perspective. The main concepts and clinical techniques of Whidam's Su-Gi therapy were summarized. Discussion : Understanding the principles of medical Gigong is necessary in order to understand the Angyo method of Doin Angyo. The principle of medical Gigong is to circulate around Three-Danjeon(丹田) on the human belly and Three-Gwan(關) on the human back by practicing medical Gigong, and to strengthen the life force by activating the viscera function by communicating between the limbs and the body. If there are Jeokchwi(積聚) and deviation, Whidam's Su-Gi therapy eliminates the Jeokchwi and adjusts the deviation. Conclusions : 1. The Angyo method of Doin Angyo originates from the practice of training to establish Danjeon for the right body and the right flow of air. 2. The principles of medical Gigong obtained through the analysis of Sojucheon(小周天) practice, Moosim-Gigong Riding stance, Moosim-Gigong Doinbeop, Hwalinsimbang Doinbeop and Donguibogam Jang-Bu Doinbeop are the medical Gigong's view of the human body and pathological perspective. 3. Whidam's Su-Gi therapy, which focuses on the elimination of Jeokchwi and the adjustment of deviation based on the medical Gigong's view of the human body, is a manual therapy that inherits the principle of the Angyo Method of Doin Angyo.

Improvement of Light Extraction Efficiency of GaN-Based Vertical LED with Microlens Structure

  • Kwon, Eunhee;Kang, Eun Kyu;Min, Jung Wook;Lee, Yong Tak
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.221-221
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    • 2013
  • Vertical LED (VLED) has been recognized as a way to obtain the high-power LED due to their advantages [1]. However, approximately 4% of the light generated from the active region is extracted, if the light extraction from side walls and back side is neglected because of Fresnel reflection (FR) and total internal reflection (TIR) [2,3]. In this study, the optical simulation of the VLED with the various microstructures was performed. Among them, the microlens having the diameter of 3 ${\mu}m$ and the height of 1.5 ${\mu}m$ shown the best result was chosen, and then, optimized microlens was formed on a GaN template using conventional semiconductor process. Various microstructures were proposed to improve the light extraction efficiency (LEE) of the VLED for the simulation. The LEE was simulated using LightTools based on a Monte Carlo ray tracing. The microstructures with hemisphere, cone, truncated and cylinder pattern having diameter of 3 ${\mu}m$ were employed on the top layer of the VLED respectively. The improvement of the LEE by using the microstructure is 87% for the hemisphere, 77% for the cone, 53% for the truncated, 21% for the cylinder, compared with the LEE of the flat surface at the reflectance of 85%. The LEE was increased by 88% at the height of 1.5 ${\mu}m$, compared with the LEE of the flat surface. We found that the microlens on the top layer is the most suitable for increasing the LEE. In order to apply the proposed microlens on n-GaN surface, we fabricated microlens on a GaN template. A photoresist array having hexagonal-closed packed microlens was fabricated on the GaN template. Then, optimization of etching the GaN template was performed using a dry etching process with ICP-RIE. The dry etching carried out using a gas mixture of Cl2 and Ar, each having a flow rate of 16 sccm and 10 sccm, respectively with RF power of 50 W, ICP power of 900 W and chamber pressure of 2 mTorr was the optimum etching condition as shown in Fig. 2(a).

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Effect of Kami-kanghwalsan (KKHS) on Atopic Dermatitis-like Skin Lesions Induced in NC/Nga Mouse by Mite Antigen Stimulation (가미강활산(加味羌活散)이 집먼지 진드기 추출물로 유도된 NC/Nga mouse의 아토피 피부염에 미치는 영향)

  • Kim, Yun-Hee;Han, Jae-Kyung;Kim, Yun-Hee
    • The Journal of Pediatrics of Korean Medicine
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    • v.22 no.1
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    • pp.69-93
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    • 2008
  • Objectives The purpose of this study is to investigate the effect of KKHS on atopic dermatitis in an in-vivo experiment using an NC/Nga atopic dermatitis mouse, which has histological and clinical similarities to this condition in humans. Methods To investigate the effect of KKHS on atopic dermatitis (AD), we evaluated atopic dermatitis-like skin lesions by clinical skin index and analyzed immunological parameters in peripheral blood mononuclear cells(PBMCs), splenocytes, draining lymph node(DLN) and performed skin histology in ears and dorsal skin of atopic dermatitis of NC/Nga mouse in vivo. Results In vivo, clinical skin severity score was significantly lower in the KKHS group than in the control group. IgE, IL-6, TNF-${\alpha}$, IgM, IgG2a and IgG2b levels in serum decreased remarkably in the KKHS group than in the control group, and the level of IFN-${\gamma}$ production which is secreted from Th1 cell was increased by KKHS. After this experiment we analyzed immunological cells ($CD3^+$, $CD19^+$, $CD4^+$, $CD8^+$, $CD3^+CD69^+$, $CD4^+CD25^+$ and $CD49b^+$) by flow cytometry. It results that the total absolute number of $CD3^+$, $CD19^+$, $CD4^+$ and $CD8^+$ cells were recovered as much as normal state, and the level of $CD3^+CD69^+$ in isolated DLN and PBMCs were significantly decreased, and total absolute number of $Gr-1^+$, $CD11b^+$ and $CD3^+$ in dorsal skin of NC/Nga mouse were decreased by KKHS. We analyzed ear, DLN, and neck-back skin after biopsy and dyeing by hematoxyline/eosin(H&E), toluidine staining (mast cells marker). KKHS were very effective to the histological symptoms which are in dermal and epidermal thickening, hyperkeratosis and inflammatory cell infiltration. Ear thickness was significantly decreased compared with the control group and the size of inflammatory lymphocytes cells (ILC) and plasma cells (PC) in DLN were also decreased. Conclusions KKHS on atopic dermatitis in an in-vivo experiment using an NC/Nga atopic dermatitis mouse was very effectiveness to the atopy dermatitis treatment.

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Dysmenorrhea and Its Related Factors among Women's High School Srudents in an Urban Area (도시지역 일부 여자고등학생들의 월경통과 관련요인)

  • Shin, Soo-Hee;Yang, Hye-Kyeong;Cho, Young-Chae
    • Journal of the Korean Society of School Health
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    • v.20 no.1
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    • pp.91-101
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    • 2007
  • Purpose: The present study intended to reveal the association between the physique of adolescent women and dysmenorrhea, and the factors related to the frequency of dysmenorrhea. Methods: The study subjects included 511 girls of a women's high school in Daejeon city and they were, during the period of March 1st through April 30th, 2005, given self-administered questionnaires about frequency of menstruation, age, physique, exercise, and such menstruation-related items as age of menarche, menstrual period and days, and amount. Results: As with the frequency of dysmenorrhea, 38.4% experienced it 「always」, 44.6% 「occasionally」, and 17.0% 「almost scarcely」, and those with dysmenorrhea accounted for 83.0% of the subjects. The frequency of dysmenorrhea was not significant difference according to the BMI and HPI. However, the lower the age of menarche and the greater the amount of menstrual flow, the more frequent dysmenorrhea. The symptoms of dysmenorrhea included the highest frequency of low back pain(68.5%) and it was followed by abdominal pain(65.9%), sensibility(54.0%), fatigue(51.7%), and nervousness(49.5%). These accompanied symptoms tended to be worse as the frequency of dysmenorrhea increased. The multiple logistic regression analysis revealed that the relative risk of frequency of dysmenorrhea is 2.2 times in age of 14, by a standard age of 15 as menarchial age, 2.2 in 13, and 3.1 in below 12. The menstrual days was 3.0 times in both below 2 days and over 8 days with the standard days of 3-7 days. The menstrual amount was 1.9 times in the group with a greater amount of menstrual bleeding and 1.5 times in the group with a less amount than the normal group, respectively. Conclusion: The above results suggest that the rate of experiencing dysmenorrhea was up to 83.0% and 38.4% from these had dysmenorrhea upon every menstruation. It is thought that dysmenorrhea could be a great disadvantage sufficient to impair optimal health to a larger body of school girls. Further, for quality of life, it is required that more fundamental strategies instead of pain killers or others for palliation of dysmenorrhea would be established among adolescents.