• School Mathematics
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• v.8 no.2
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• pp.215-237
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• 2006

In this study, we research distinctive features of geometry problem solving of middle school students whose mathematical achievement levels are distinguished by National Assessment of Educational Achievement. We classified 9 students into 3 groups according to their level : advanced level, proficient level, basic level. They solved an atypical geometry problem while all their problem solving stages were observed and then analyzed in aspect of development of geometrical concepts and access to the route of problem solving. As those analyses, we gave some suggestions of teaching on mathematics as students' achievement level.

• 한국노년학
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• v.31 no.4
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• pp.1135-1153
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• 2011

The study aims to examine the interaction of socio-economic status in education and income in the difference of the level of subjective health, physical health, and mental health of middle-age and the elderly of Korea. While there have been various discussions in precedent study with respect to the serious increase in the number of dependent life alongside with increasing elderly population, research on the health level according to socio-economic status is highly limited, and also how the health level of middle-age and the elderly - whom will arrive at senescence in just a few years - is different. The study aims at analyzing the health level by hierarchy and age based on data targeting the whole nation. As for analysis data, the study utilized 1st Korean Longitudinal Study of Ageing (KLoSA) implemented by Korea Labor Institute, and carried out a path analysis to verify whether income and academic background serve as a parameter to the level of subjective health, physical health, and mental health. As a result, while the subjective health level decreases, the study confirmed an increase in chronic diseases, and extremely low level of mental health when people in middle-age enter the elderly. In addition, the higher the education and income, the more the health levels both on middle-age and the elderly; the result suggests that education background and income have mediated effects in all health level of middle-age and the elderly.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.02a
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• pp.104-110
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• 2002

본 연구는 보행형 관리기의 손으로 전달되는 진동특성을 실험적으로 해석하고 평가하며 방진 방안을 제시할 목적으로 수행되었다. 관리기의 작업기 중에서 설문을 통해 사용 빈도가 높은 3개의 작업기(중경로터리, 중경제초기, 구굴기)를 선정하였고 각 작업기별 진동수준을 측정하였다. 진동 방지 방안에 대해서는 4개의 방진 장치(고무 패드, 방진 장갑, 핸들 방진 장치, 엔진 마운트)를 선정하여 각 방진 장치별 진동수준을 측정하였다. 방진 장치의 성능을 정확하게 비교하기 위해 진동의 측정은 진동수준이 가장 높은 구굴기에서 수행되었다. 실험결과에 의하면 관리기 작업이 작업자의 인체에 해를 끼칠 위험이 매우 크지만 이 결과는 작업자가 매일 3시간씩 관리기를 사용할 경우를 기준으로 설정한 값이기 때문에 실제로 관리기 사용일수가 많지 알은 대부분의 우리나라 사용자들에게 적용하는데는 한계가 있음을 밝힌다. 그렇다 하더라도 관리기의 주 사용자는 보행형 관리기 뿐만 아니라 보행형 경운기나 보행형 이앙기 등의 손으로 전달되는 진동이 심한 기계를 함께 사용하는 경우가 많음을 고려하면 방진 장치를 개발하거나 진동수준이 낮은 농작업기계를 개발하여 작업환경을 개선하는 조치가 필요하다고 생각한다. 그러므로 농작업기계에 대한 진동수준에 대한 종합적인 연구와 그에 대한 대책 마련이 지속적으로 수행되어야 할 것이다.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.146.1-146
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• 2003

연근의 박피에 따른 감모율은 10%를 넘지 않는 낮은 수준으로 우엉과 마찬가지로 brushing에 의한 박피가 가장 효과적이어서 감모율이 5.1% 수준으로 가장 낮게 나타났다. 박피 처리후의 수분함량 변화도 근채류 전용박피기가 89.24∼87.27% 수준으로 차이가 가장 적게 나타났으며 박피 처리후의 갈변도도 0.02∼0.09 수준이었다. pH 변화도 근채류 전용 박피기에서 6.0∼6.5 수준이었으나 그 밖의 처리구에서는 거의 변화가 없었다. 한편, 마에 있어 박피 감모율은 우엉 및 연근과 비슷한 경향을 보여 brushing 처리에 있어 3.28% 수준, 근채류 전용박피기에서도 5.23%로 낮은 감모율을 나타내었다. 또한, 수작업에 의한 박피 시료는 brushing과 근채류 전용 박피기로 처리한 시료와 비교하여도 처리후의 수분함량 변화, 갈변정도, pH변화 등의 품질적으로 크게 차이가 없었으나 감모율은 9％ 수준으로 높게 나타났다. 그리고 실험에 사용한 6가지 근채류 중에서 화학적 박피가 가장 효과적인 품목으로 가열 온도 및 시간의 영향을 크게 받지 않는 것으로 나타났다.

• Journal of the Korean School Mathematics Society
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• v.22 no.4
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• pp.483-500
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• 2019

This study compared and analyzed the van Hiele levels of geometry contents in middle school mathematics textbooks and those of students' thinking. As the mathematics curriculum was revised recently, the amount of contents in the geometry area were reduced, but the van Hiele level did not change much, and the gap between the van Hiele level of geometric contents presented in the textbooks and the level of students' geometric thinking still remained unchaged. The van Hiele levels of the geometric contents in the textbooks were distributed in the levels of 1, 2, 3 in the first grade, and 2, 3, 4 in the second and third grade. In the case of the first grade, 69% of the students were less than or equal to level 2, and 73.7% and 47.6% of the students in the second and third grades were less than or equal to level 3, respectively. Especially, in the case of the second and third grade, the ratio of the 4th level of the contents presented in the textbook is higher than the problem, which can cause difficulties for the students.

• Journal of Digital Convergence
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• v.12 no.9
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• pp.417-422
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• 2014

This paper was to explore the effect of aging anxiety of the middle-aged on depression in aging society. This survey was conducted from September, 2013 to December, 2013 and 302responses from the survey were used for the analysis. The data was analyzed by descriptive statistics, t-test, ANOVA, pearson correlation and Multiple Regression. The research findings could be summarized as the followings. First, the mean scores of aging anxiety and depression were lower than average. Second, aging anxiety was the significant predictor to explain depression. Third, income also was the significant predictors which have the effectiveness to the depression.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.8
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• pp.327-336
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• 2007

Lots of effort toward design optimizations have been paid for a cost-effective system design in various ways from a transistor level to RTL designs. In this paper, we propose a bit level optimization of an adder design for expanding its design space. For the bit-level optimization, a heterogeneous adder organization utilizing a mixture of carry propagation schemes is proposed to design a delay-area efficient adder which were not available in an ordinary design space. Then, we develop an optimization method based on Integer Linear Programming to search the expanded design space of the heterogeneous adder. The novelty of the Proposed architecture and optimization method is introducing a bit level reconstruction/recombination of IPs which have same functionality but different speed and area characteristics for producing more find-grained delay-area optimization.

• Journal of the Korean School Mathematics Society
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• v.22 no.3
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• pp.257-275
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• 2019

Technology-based convergence education is being emphasized for students in the era of the fourth industrial revolution. In math education, students need to increase their capabilities in the future by having them experience mathematical problems using robots and sensors, a key technology in the era of the fourth industrial revolution. To this end, it is necessary to present educational uses for educational robots in relation to math and curriculum from a 'mathematics education perspective' and analyze its educational use in relation to the mathematics and curriculum, considering the role of mathematics at the base of the process of exploring real-world phenomena and solving problems. Based on the analysis of Van Hiele levels of development in geometry and the LOGO activity level of Olson et al.(1987), this study analyzed and presented the level of LEGO Mindstorm activity, a representative educational Robot capable of collecting and analyzing data and programming in the form of block language, in the first to fourth level.

• The Transactions of the Korea Information Processing Society
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• v.2 no.6
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• pp.815-822
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• 1995

In the conventional UNIX system, the all device driver realized in the kern el. Hence, whenever we want to add a new device driver or change the existin g device driver, the modification of kernel is unavoidable. Generally, it is very difficult to modify the kernel codes.As a method of overcoming this difficulty, a TTY device driver model of user-level is presented in this paper. The basic concept of this model is providing a dynamic reconfiguration of TTY device driver by realizing a user-level server process for TTY device driver. In order to verify the proper y of this model, a prototype of TTY device driver has been realized in the SunOS and Linux environment and evaluated its performance.

• Journal of the KSME
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• v.35 no.1
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• pp.63-70
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• 1995

연사기는 섬유공정 중에서도 기본적인 제직 준비공정으로서 연사기 시장은 개발도상국의 섬유 산업 진흥과 더불어 날로 확대되고 있다. 최근 섬유산업이 요구하는 연사기의 성능은 범용성\ulcorner 효율성 및 다양한 보조기능(실잇기, 패키지교체, 왁스나 요일의 첨가 등의 기능을 자동화하는 것 등)의 구비 등이다. 연사기의 생산성은 스핀들의 회전수가 높을수록 증대되므로 고속회전체 기 술의 개발이 시급하며, 다양한 기능의 자동화에 대한 연구\ulcorner개발이 뒷받침되어야 한다. 현재 우 리나라 연사기 기술수준은 다른 섬유기계에 비해 선진국 수준에 가깝게 접근해 있다. 따라서 연사기는 우리 섬유기계 산업계와 기계공학인 여러분의 적극적인 관심과 노력이 모아진다면 비 교적 단시간 안에 선진국과 견줄 수 있는 분야라고 생각된다.