• 대한수학교육학회지:수학교육학연구
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• 제18권4호
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• pp.455-467
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• 2008

우리는 '중학교 수학에서의 증명과 논증'의 의미와 수준의 설정을 검토할 필요가 있다. 중학생 수준에서의 증명과 논증은 모두 학습 집단 속에서의 의사소통을 통한 인간 활동으로 보아야 하며, 이에 부합하도록 수업의 방향을 잡아야 한다. 이런 노력의 일환으로, 우리는 중학교 기하수업 개선을 목적으로 중학교 2학년학생들을 대상으로 2년 동안 기하탐구교실 수업을 진행해 왔다. 우리는 이 수업 중 벌어진 상황 중하나를 선택하여, 최초 발현된 학생들의 증명 도식이 상호교섭의 과정을 통해 어떻게 교실에서 수용되는 증명 도식으로 형성되어 가는지 그 과정을 살펴볼 것이다. 네 단계에 걸친 활동을 통해 기하탐구교실에서의 증명은 학생들에 의해 발현된 초기 증명 도식에서 출발하여 상호교섭의 과정을 통한 결과물로서의 기하탐구교실만의 증명 도식의 생성으로 이어진다. 우리가 이 과정에 주목하는 이유는 교섭의 산출물이 갖는 수학적 완결성 때문이 아니라, 그것이 갖는 의사소통과 상호 이해, 상호참조라는 가치에 있으며, 이것이야말로 수학교실에서 수용될 수 있는 적법한 증명이라는 것을 말하기 위해서다. 이상과 같이 우리는 기하탐구교실이라는 학생들의 참여를 통해 공동체 내에서 수용되는 증명의 수준이 어디까지이며, 그것이 어떤 협상 과정을 거쳐 수립되는지 살펴보았다. 이 과정은 동시에 학생들 스스로 증명을 학습해 가는 과정이기도 하다.

• 대한수학교육학회지:수학교육학연구
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• 제25권2호
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• pp.225-240
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• 2015

본 연구에서는 중점연결정리의 사각형으로의 확장을 소재로 학교수학에서 다루어지는 증명의 대표성에 대해 고찰하였다. 다양한 사각형을 생각하고, 그에 맞는 중점연결정리의 확장을 증명하였으며, 이들 증명 간의 관계를 파악하여 학교수학에서의 증명이 대표성을 가짐을 보였다. 한편, 이러한 내용에 기초한 실태조사에서 학생들은 사각형 종류의 일부만을 찾았으며, 찾은 사각형 각각에 대한 증명은 쉽게 완성하였으나, 같은 수학적 사실을 증명하고 있음에도 대상 도형이 바뀌면 다른 증명 방법이나 수학적 개념을 사용하는 경향을 보였다. 따라서 증명들 간의 관계를 파악하는 것을 어려워하였다. 이러한 사실들은 구체적 도형에 대한 증명은 할 수 있으나, 증명들 간의 관계를 이해하여 일반화하는 증명의 대표성에 대한 이해는 부족함을 보여준다. 따라서 증명활동이 유기적이고 의미론적으로 이루어질 필요가 있음을 알 수 있다.

• 한국컴퓨터정보학회논문지
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• 제20권7호
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• pp.115-120
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• 2015

The old people's feelings, emotions, and self-evaluative judgements fluctuate overtime. The purpose of this paper is to proof relations among well-being factors in social activity. Major results of this paper was as follows. First, the social activity participated elderly had higher health status, self-esteem, mental-health, and successful aging than the non-participated elderly. Second, self-esteem and mental health were exposed as important variable for all of the two groups to improve the successful aging. Thus, self-esteem and mental health can become significant indicator of self-empowering and psychological resilience. Third, the strongest total causal effect of successful aging was health status in social activity participated elderly, while self-esteem was the greatest total causal effect of it in the non-participated elderly. Health status had higher indirect effect of successful aging than direct effect of it in both of them.

• Journal of Microbiology and Biotechnology
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• 제8권6호
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• pp.669-675
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• 1998

Taq DNA polymerase exhibits a sizable drawback compared to the other thermophilic DNA polymerases in that it demonstrates lower proof-reading activity due to the deficiency of 3'-5'exonuclease activity. A study was undertaken to improve the 3'-5' exonuclease activity in the PCR of Taq DNA polymerase. The three-dimensional structural alignment of the polymerase and 3'-5' exonuclease domains from the pol I family DNA polymerases explains why Taq DNA polymerase has just a background level of 3'-5'exonuclease activity. A comparison indicated that the two polymerase domains are very similar in primary and tertiary conformations, even though Taq DNA polymerase carries a much shorter 3'-5'exonuclease domain than that of E. coli DNA polymerase I. Those two polymerase domains were interchanged between Taq DNA polymerase and E. coli DNA polymerase I. The 3'-5' exonuclease domain from E. coli DNA polymerase I was separated and pasted into the polymerase domain of Taq DNA polymerase I, which resulted in a functional fusion-Stoffel fragment. The 3'-5'exonuclease activity of the fusion-Stoffel fragment increased up to 48% of the value of the Klenow fragment, while that of Taq DNA polymerase remained at 6.0% of the Klenow fragment.

• 한국의류산업학회지
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• 제11권5호
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• pp.827-832
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• 2009

The purpose of this study is to scientifically proof possibility of development of natural dye which has antimicrobial activity with Chelidonium majus var. asiaticum. For that silk fabrics dyed with Chelidonium majus var. asiaticum extracts were tested for anti-microbial activity. Bacterials used for test of anti-microbial activity were Staphylococcus aureus ATCC 6538, Klebsiella pneumoniae ATCC 4352 and Trichophyton mentagrophytes IFO 5466. The results of experiment were as follows ; 1. The more the number of times of dyeing increase the more value of K/S increased. 2. Reduction of bacterium against Staphylococcus aureus ATCC 6538 of silk fabrics dyed with Chelidonium majus var. asiaticum extracts was 99.9% without reference to the number of times of dyeing. 3. Reduction of bacterium against Staphylococcus aureus ATCC 6538 of silk fabrics dyed with Chelidonium majus var. asiaticum extracts was 99.9% after irradiation of 20 hour without reference to the number of times of dyeing. 4. Reduction of bacterium against Staphylococcus aureus ATCC 6538 of silk fabrics dyed with Chelidonium majus var. asiaticum extracts was over 94.8% after dry cleaning. As above silk fabrics dyed with Chelidonium majus var. asiaticum extracts were acquired a high anti-microbial activity against Staphylococcus aureus ATCC 6538.

• Natural Product Sciences
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• 제16권4호
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• pp.239-244
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• 2010

Protein tyrosine phosphatase 1B (PTP1B), a negative regulator of insulin signaling, has served as a potential drug target for the treatment of type 2 diabetes. The MeOH extracts of twenty-nine medicinal plants, traditionally used in Vietnam as anti-diabetes agents, were investigated for PTP1B inhibitory activity in vitro. The results indicated that, most materials showed moderate to strong inhibitory activity with $IC_{50}$ values ranging from $3.4\;{\mu}g/mL$ to $35.1\;{\mu}g/mL$; meanwhile, eleven extracts (37.9%) could demonstrate PTP1B activity with $IC_{50}$ values less than $15.5\;{\mu}g/mL$; sixteen extracts (55.2%) could demonstrate PTP1B activity with $IC_{50}$ values ranging from $15.5\;{\mu}g/mL$ to $35.1\;{\mu}g/mL$. The study may provide a proof, at least in a part, for the ethno-medical use in diabetes disease of these plants.

• 한국의류학회지
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• 제30권8호
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• pp.1178-1187
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• 2006

The purpose of this study is to conduct a questionnaire survey on the actual conditions of the working uniform and protective equipment put on by street cleaners, then to identify their inconvenience and problems and to draw solutions to improve them, and finally to design a spring-and-autumn street cleaner uniform which has enhanced functionalities such as motional flexibility, safety and soil proof. The questionnaire survey of this study was done by street cleaners who were in charge of street cleaning and collecting the recyclable waste. The result of this study, easily worn-out parts of the working clothing were the sleeve hems and the front part on the upper uniform, and the trouser hems and zipper on the lower uniform. Easily soiled parts were the sleeve hems, parts of arm on the upper uniform, and the trouser hems and knee parts on the lower uniform. Based on the results of the questionnaire survey, the sample uniforms were designed in consideration of material, design and pattern. A soil-proof material was used for easily soiled parts such as sleeve hems, knee parts and trouser hems. Reflective material was applied to the parts such as chest, back and the side lines of sleeves and trousers to raise visibility in working and to ensure safety. A crease was given to each side of the back. The height of sleeve cap was lowered to lift the motional flexibility of back and arm parts. Darts were applied to elbow and knee parts for a three-dimensional design. Gussets were inserted in the thigh part to give it activity. Then quantitative evaluation and a sensory evaluation, which was composed of outward appearance, motional flexibility and fitness for field operation, were conducted. According to these evaluations, the sample uniform was found to be more satisfactory than current uniform.

• 한국신뢰성학회지:신뢰성응용연구
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• 제1권2호
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• pp.79-93
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• 2001

Recently, new aspects of paints such as a beautiful appearance, use of environmentally friendly paints, etc., in addition to the superior performance of paints have been requested for industrial paints including the paints for heavy construction equipment and others. Particularly, the quality of appearance of coating affects the sales of heavy construction equipment. And the necessity for the paints to have a superior weather-proof property without changing the luster or color even after long-time exposure to the open air is emphasized. The change in the surface color and luster of the paint due to the natural environment progresses very slowly, and it takes a long time to verify material properties when developing new paints. In order to improve such methods, weathering tests are performed in many laboratories as a test for accelerating aging of coating, and the lifetime of the products is estimated through evaluation of the weathering (environment-proof) quality of paints. However, not a great deal of research activity has been conducted up to the present time since the interrelationship between the actual results of testing and field data is different for each paint and it takes a long time to study relevant materials. Therefore, introduced in the present study is the estimation of the change in the quality of appearance of coating in the field through the accelerated aging test among the cases of improvement of the quality of appearance of the urethane paint for heavy construction equipment.

• 한국의류산업학회지
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• 제7권4호
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• pp.371-377
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• 2005

The purpose of this study is to consider 1990s fashion design involving the utility of function which is the essence of modernism. First, documentary studies about the aesthetic value of the utility of function throughout the 20th century sociocultural contexts has been done. Second, content analysis of articles in American "Vogue" from 1990 to 2002 has been accomplished to hold the actual proof for the utility of function in postmodernism fashion. As a result, the utility of function has been defined the utility of body activity, the utility of practical use, and the utility of mechanical product. According to contents analysis, new aspects has been introduced in use of high-tech fabrics, ornaments, and mass customization in 1990s. In conclusion, the utility of function in fashion has been improved in accordance with the change of sociocultural contexts and women's wants.

• 전기의세계
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• 제30권10호
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• pp.639-644
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• 1981

PVC is a kind of electric insulation polymer. But we get some deteriorations in electrical characteristics of the PVC, when it is used on the radioactive field. In order to find out the cause of the deterioration, we investigate the surface-resistance, volume-resistance, dielectric constant and dielectric loss angle of the soft and hard PVC which is irradiated by the Co$^{60}$ .gamma. radioactivity. From the experiment, we can conclude the followings 1. Radio-activity proof characteristic in the soft PVC is stronger than in the hard PVC. 2. The resistance of PVC which is irradiated by the radio-activity decrease exponentially. 3. The dielectric constant and the dielectric loss angle of PVC irradiated by Co$^{60}$ .gamma.ray reach maximum value in first few time.