• Journal of Educational Research in Mathematics
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• v.12 no.4
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• pp.457-472
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• 2002

In this paper, we deal with the algebraic thinking from the perspective of ‘process’ and ‘object’ aspects. Generally, mathematical concepts have come from the concrete process. We consider the origin of algebra as the arithmetic calculations. Also, the concept of school arithmetic is beginning from actions or procedures. However, in order to develop the alge- braic thinking and to apply this thinking, we have to see the history of algebraic thinking, and find this duality. Next we investigate various researches relating to the ‘process-object duality’. Theses studies suppose that the concept formation and thinking process should be stared from the process-object duality. Finally, we reinterprete many difficulties in algebra - equals sign, variables, algebraic expressions, and linear equations, the principle of permanence of form- from the perspective of the process-object duality.

• Journal for History of Mathematics
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• v.25 no.4
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• pp.69-82
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• 2012

The objective of this paper is to study De Morgan's perspective on teaching and learning complex numbers. De Morgan's didactical approaches reflect the process of development of his thoughts about algebra from universal arithmetic, symbolic algebra to meaning algebra. De Morgan develop his perspective on algebra by justifying and explaining complex numbers. This implies that teaching and learning complex numbers is a catalyst for mathematical development of De Morgan.

• Korean Journal of Childcare and Education
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• v.8 no.6
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• pp.193-217
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• 2012

This study developed and applied the 'field-university-government cooperation oriented supervision program' for child-care centers. A draft of the 'field-university-government cooperation oriented supervision program' was drawn up from the Delpi method with a panel consisting of experts, and from teachers's perception on it's adequacy. And then it was applied to A child-care center. Participating subjects consisted of a panel of 20 experts, 153 child care center teachers and 1 director and 4 teachers in child care centers, 1 professor in an university. The step by step results of the study are 1) the developed draft of the 'field-university-government cooperation oriented supervision program', included two categories and consisted of a total 63 items; 2) when the program was applied, participant' responses through the supervision was summarized as 2 key words, 'new attempt vs limits of unprepared collaboration', 'confusion and further possibility'. In conclusion, this program showed both possibility and limitations.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.17 no.4
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• pp.221-231
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• 2005

The present study is deeply concerned with the reliability design method(Level III) for caisson breakwaters using expected sliding distance, and the objectives of this study are to propose the employment of a doubly-truncated normal distribution and to present the validity for it. In this study, therefore, the explanations are made for consideration of effects of uncertain factors, and a clear basis that the doubly-truncated normal distribution should be employed in the computation process of expected sliding distance by Monte-Carlo simulation is presented with introduction of the employment method. Even though only caisson breakwaters are treated in this paper, the employment of doubly-truncated normal distribution can be applied to various coastal structures as well as other engineering fields, and therefore it is expected that the present study will be extended in various fields.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.220-220
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• 2016

최근 국지적 기상변화에 따른 도시 산악지역의 돌발홍수 발생빈도가 증가함에 따라 위험기상 관측 및 홍수의 사전감지 대응에 대한 관심과 필요성이 증대되고 있다. 이에 발맞춰 국토교통부 및 기상청 등에서는 이중편파레이더를 설치 운영 중에 있으며, 이를 이용한 정량적 레이더강수량 추정 및 예측에 대한 연구가 활발히 진행 중이다. 레이더를 이용한 정량적 강우추정을 위해서는 레이더관측, 신호처리, 품질관리(QC), 강우추정 알고리즘 적용, 보정 등 일련의 과정을 거치게 되며, 이러한 과정 속에서 다양한 불확실성 요소가 존재하기 때문에 레이더자료의 정확도에 대한 평가가 요구되고 있다. 그러나 레이더강우량의 불확실성이 어느 정도 수준인지 정량적으로 제시하기는 어려우며, 그 기준 또한 모호하다. 따라서, 본 연구에서는 총 25개 강우사상(2012 ~ 2014년)을 대상으로 비슬산강우레이더 관측자료와 관측영역 내 지상강우자료를 이용하여, 누적강우량, 평균차, 상대분산, 변동계수 등을 통해 레이더강우의 정량적인 불확실성을 요약 제시하고자 하였다. 본 연구는 레이더강우의 정량적인 불확실성을 파악할 수 있는 기초적인 과정이며, 도출된 연구결과는 현재 레이더강우 추정의 수준을 파악하고 추후 레이더강우의 개선 수준을 비교 검토 할 수 있는 자료로 활용이 가능할 것으로 판단된다.

• Journal of Welding and Joining
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• v.9 no.4
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• pp.1-8
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• 1991

용접구조물을 그의 사용목적에 적합하게 제작하려면 그의 구조설계와 사용재료의 적절한 선택과 사용성능을 충분히 확보하게 끔 제작과정과 품질보증을 할 수 있는 것이 필요하다. 즉 용접성 (Weldability)을 만족하게 하는 것이다. 구조물의 제작에 있어서 배려하여야 할 것은 구조의 사 용성능의 확보와 안전성인 것이다. 사용성능이란 구조의 강도, 기능 그리고 미관이나 끝내기의 외관적 성능등이다. 우리들의 생활공간에 존재하는 구조물이 한번 파손이나 파괴의 사고가 발 생하면 치명적인 것이 된다. 용접설계 생산과 제작의 기술적인 준비로써 용접구조물을 대상으로 용접가공에 중점을 두어 사용되는 말이다. 용접설계는 구조물과 제품의 용접제작과정을 완전히 지시하고 용접이음에 요구되는 사용성능이 확보 되게 끔 부재배치와 치수등이 선정되고 제작과 검사등의 실제 작업성을 충분하게 고려한 제작계획을 세우는 것을 말한다. 이와 같이 된 용접 설계를 바탕으로 용접기술자가 최적한 용접재료의 용접조건등을 결정한다. 즉 설계와 용접시공은 서로 밀접한 관계를 갖고 있어야 한다. 특히 용접설계의 비교적 초기단계에 속하는 것은 제품 기본계획과 강도해석 그리고 구조설계의 과정에 반드시 용접기술자의 관여가 필요한 것이다. 그리고 설계의 최적화를 위하여는 많은 정보 특히 경험적인 정보와 구조 해석적인 정보가 잘 처리되어야 한다. 오늘날의 CAD의 도입이란 전산기의 처리기술과 graphic기술을 묘미 있게 이 용한 것이라 할 수 있다. 용접구조물의 용접성을 논술하려면 다음과 같이 구분하는 것이 바람 직하다. 1. 용접구조물의 허용강도 2. 동접구조용의 강의 선택 3. 용접시공조건 4. 용접설계 이중 용접 제작과정을 표 1에 나타내었다. 구조물의 용접설계 요구조건으로써, 1)손상, 2)탄성 파손, 3)항복응력, 4)기계적인 불안정성, 5)파괴와 붕괴등을 고려하여야 하며 구조용 강의 선택은 1. 강도(strength) 2.연성(ductility) 3.인성(toughness)을 고려하여 구조물의 설계에 충분히 만 족해야 한다.

• Korean Journal of Social Welfare
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• v.68 no.2
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• pp.27-51
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• 2016

This paper is about the NOOMP(Not Out of My Pocket) phenomenon, the inconsistent welfare attitude for an expansion of welfare system and increase of financial resources. By analyzing the scale and influential factors of the NOOMP to the main welfare programs, focusing on the class, gender, and age group, the paper tries to investigate the relationship between the NOOMP and the inherent stratification structure of each programs. This paper uses the Additional Survey of Welfare Attitude in 2013 Korea Welfare Panel Survey. As a result of analysis, low level of NOOMP phenomenon has been observed in welfare programs for whole society members such as health policies, pension, employment policies, compared to those of targeted programs for the poor, aged, or disabled. In addition, high probability of each group of 'low incomer', 'female', and '20s or less'to the NOOMP phenomenon has been appeared, therefore, high relevance of the NOOMP and the stratification structure of welfare programs have been confirmed. These results indicate that the transition to the universal welfare programs and the improvement of welfare programs for more equal structure are needed to reduce the NOOMP phenomenon.

• 한국노년학
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• v.41 no.4
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• pp.527-546
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• 2021

This study examined the effect of past acceptance on suicidal ideation in older adults and verified double mediation effects of attitude to aging and depression. The responses of 329 aged 65 years or older who participate in senior welfare centers in Seoul and Gyeonggi-do were used. As an analysis method, the double mediation effect was confirmed through serial multiple mediation model verification using the SPSS PROCESS macro program. The followings are the results of the study. First, the past acceptance had a significant effect on the aging attitude, the aging attitude on the depression, and the depression on the suicidal ideation, but the direct effect of past acceptance on the suicidal ideation was not significant. Second, double mediation effects of attitude to aging and depression were significant in the relationship between past acceptance and suicidal ideation. Based on these results, practical and policy interventions to prevent suicide in old age were suggested.

• Journal of Venture Innovation
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• v.4 no.3
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• pp.89-108
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• 2021

This study purposed to investigate the double mediating effect of the resistance and the job stress between the acceptance and the flourishing in organizational change. The survey has executed on 300 employees. The acceptance of organizational change was positively related to the flourishing, negatively to the resistance of organizational change and the job stress. The resistance of organizational change was positively related to the job stress, negatively to the flourishing. The job stress was negatively related to the flourishing. The resistance of organizational change was meditating the acceptance to change and the job stress, and the acceptance to change and the flourishing. The job stress on the acceptance to change and the flourishing partially mediated as well as the resistance to change and the flourishing. The resistance to change and the job stress double meditated the acceptance to change and the flourishing. The implications, limitations of this study for future research were discussed.

• Korean Journal of Cognitive Science
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• v.14 no.1
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• pp.17-28
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• 2003

In order to provide natural images with a specified depth through three-dimensional display system, the stereo images should be similar to those projected from real environment as much as possible. Even when two persons see an identical scene, the binocular Parallax between two images of an object varies as a function of one's inter-pupilary distance (IPD). In this study, we investigated whether individual differences, such as IPD and accommodative vergence, would affect the perception of three dimensional scene provided by stereo-images. Results showed that a person's IPD is correlated with the limit of screen and binocular parallax for single vision, and affects the perceived depth of an object on fixation. More specifically, with longer IPD the limit of screen and binocular parallax for single vision is decreased, and the perceived depth is reduced. These results suggest that the screen and binocular parallax of an object should be calibrated with regard to users IPD to provide natural stereo-images with a specified depth and to Prevent double vision.