• School Mathematics
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• v.5 no.3
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• pp.297-314
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• 2003

Mathematics students must appropriate their mathematical knowledge which has the definition and theorem of mathematics, algorithm, reasonable thought, heuristic, and mathematics language, and so on. That is, students should construct, use, and apply their own knowledge during learning. Appropriation of mathematical knowledge is practicable when mathematics language is in charge of many functions that Vygotsky cited. To reach the potential development level with mathematics language, students need the zones that they interact themselves and peers, as well as teacher. On that ground, this study presented the interactional zones of IZPD, ZPP, and ZAD, and modeled mathematics learning. By the case of 2 students, we found that ZPP and ZAD were necessary and important.

• Spatial Information Research
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• v.20 no.4
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• pp.83-92
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• 2012

Location-based services (LBS) are increasingly popular due to the improvement of geo-positioning capabilities and wireless communication technology. However, in order to enjoy LBS services, a user requesting a query must send his/her exact location to the LBS provider. Therefore, it is a key challenge to preserve user's privacy while providing LBS. To solve this problem, the existing method employs a 2PASS cloaking framework that not only hides the actual user location but also reduces bandwidth consumption. However, 2PASS does not fully guarantee the actual user privacy because it does not take the real user distribution into account. Hence, in this paper, we propose a nearest neighbor query processing algorithm that supports K-anonymity property based on the weighted adjacency graph(WAG). Our algorithm not only preserves the location of a user by guaranteeing k-anonymity in a query region, but also improves a bandwidth usage by reducing unnecessary search for a query result. We demonstrate from experimental results that our algorithm outperforms the existing one in terms of query processing time and bandwidth usage.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.71-71
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• 2017

플라즈마를 이용하는 건식 식각 또는 박막 증착 장비(PECVD)의 경우 웨이퍼에 rf bias를 인가하여 이온의 에너지와 입사각을 조절한다. 종래에는 웨이퍼의 가장 자리 3 mm영역을 공정 대상에서 제외하는 exclusion area로 지정하였으나 점차 공정 기술의 발달로 2 mm 이내로 감소하고 있다. 따라서 웨이퍼의 가장 자리에서 발생하는 전기장의 방향 및 크기 변화를 조절할 수 있는 기술의 개발이 필요하게 되었으며 그중 핵심적인 부품이 Si 또는 SiC로 제작되는 edge ring이다. Focus ring이라고도 불리는 이 부품은 웨이퍼 상에서 반경 방향으로 흐르는 가스의 유속이 가장 자리에 근접하면 빨라지는 현상과 이에 의해 식각/증착 화학 반응 속도가 증가하는 문제를 완화하기 위한 것과 적절한 전기 전도도를 부여함으로써 가장 자리의 전기장 분포를 최적화 할 수 있는 새로운 설계 변수로 활용할 수 있다. 스퍼터링의 경우에도 웨이퍼 중앙과 주변 부는 마그네트론 음극의 회전 링과의 입체각이 차이가 나므로 가장 자리의 경우 트렌치나 홀의 내측이 외측에 비해서 증착막의 두께가 얇아지는 문제가 있으며 건식 식각의 경우 홀의 형상이 수직에서 벗어나는 경향이 발생할 수 있다. 또한 사용 시간에 비례해서 edge ring의 형상이 변화하는데 상대적으로 고가품이어서 교체 주기를 설정하는 보다 합리적 기준이 필요하다. 본 연구에서는 전산 유체 역학 모델을 사용하는 ESI사의 CFD-ACE+를 활용하여 edge ring의 형상과 재질이 갖는 영향을 전산 모사하기 위한 기초 작업을 그림 1과 같이 진행하였다. 2D-CCP model에 Ar 가스를 가정하고 비유 전율 10내외 전도도 $0.1/Ohm{\cdot}m$정도의 재질에 대한 용량성 결합 플라즈마에 대해서 계산을 하고 이 때 기판에 인가되는 고주파 전력에 의한 이온의 입사 에너지 분포 및 각도 분포를 Monte Carlo 방법으로 처리하여 계산하였다.

• The Mathematical Education
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• v.55 no.3
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• pp.383-396
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• 2016

This study investigated highschool students' brain waves on functional tasks such as a transition(F task) from equation to graph and the other transition(G task) vice versa. A total of 39 students participated in the study who attended a high school located in Gyunggi province. These students were divided into two groups, HMA and LMA by MASS test revised by Ko, & Yi (2012). The functional tasks for the stroop task to measure EEG were provided from a previous study, Seok(2015). The results indicated two groups on G tasks showed deeper and wider brain waves which demonstrated G tasks were more difficult than F tasks. However, HMA group had an effect of the non-psychological program which had given more chances on G tasks rather than F tasks within Students' Zone of Proximal Development. Also, HMA group's brain waves had more ranges in amplitude and width of waves. These results imply that the characteristics of students' brain waves with math anxiety are consistent to the previous studies.

• Journal of Educational Research in Mathematics
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• v.12 no.4
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• pp.473-491
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• 2002

This article analyzes mathematics education from dialectical materialism acknowledging the objectivity of knowledge. The thesis that knowledge is objective advances to the recognition that knowledge will be internalized, and an idea of zone of proximal development(ZPD) is established as a practice program of internalization. The lower side of ZPD, i.e. the early stage of internalization takes imitation in a large portion. And in the process of internalization the mediational means play an important role. Hereupon the role of mathematics teacher, the object of imitation, stands out significantly. In this article, treating the contents of study as follows, I make manifest that teaching and learning in mathematics classroom are united dialectically: I hope to findout the method of teaching-learning to mathematical knowledge from the point of view that mathematical knowledge is objective; I look into how analysis into units, as the analytical method of Vygotsky, has been developed from the side of mathematical teaching-learning; I discuss the significance of mediational means to play a key role in attaining the internalization in connection with ZPD and re-illuminate imitation. Based on them, I propose how the role of mathematics teachers, and the principle of organization to mathematics textbook should be.

• Research in Mathematical Education
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• v.4 no.1
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• pp.33-43
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• 2000

The purpose of this paper was to introduce sociocultural theory which is a different epistemological perspective from constructivism and to understand the sociocultural theory in a systemic way by providing four specific criteria for a sociocultural theory from the analysis of Vygotsky's ideas. The four criteria are the followings: first, the origin of learning is not at the individual level, but at the social. Second, Learning takes place in a sociocultural framework through ZPD and there exists the stage of pseudo concept before it gets to a true concept. Third, a clear focus on action, especially mediated action, and the concept of psychological tools should be discussed in the boundary of a sociocultural theory. Fourth, actors in a learning process are not an individual child alone. In consequence, the role of adults, particularly teachers, are significant in a child's learning, and this fact provides a great potential for the active role of teachers in the students' learning of mathematics from the sociocultural perspective.

• Journal of the Korean Electrochemical Society
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• v.2 no.1
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• pp.46-49
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• 1999

Lithium cobalt oxide cathode for thin-film rechargeable lithium batteries were fablicated by electron-beam evaporation. Annealed lithium cobalt oxide, which was deposited on to stainless steel substrate, showed well-developed (003) planes of the hexagonal structure and potential plateau at $\~3.9 V$. Lithium cobalt oxide thin films had the stoichiometric Li/co ratio at high deposition rates and exhibited high discharge capacity at $15{\AA}/s$. As the annealing temperature increased, discharge capacity increased with maximum value at $700^{\circ}C$, but showed low capacity as a result of reaction with substrate above $700^{\circ}C$. Unuiformity of the lithium and cobalt in the depth profile gave initial capacity loss with charge/discharge performance.

• Journal of Korea Entertainment Industry Association
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• v.15 no.4
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• pp.229-242
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• 2021

The purpose of this study is an empirical case study that focuses on bring about changes in clients through narrative therapy using scaffolding. Through this, the purpose was to find the preferred values and hopes of the future among the stories that the client's has lived in. As the research method, we proceed through unstructured interview and loose structures in qualitative research. On this premise, the counselor did not diagnose or explain the 'decentralized but influential' attitudes and problem. And there was no order in the conversation, and I didn't decide in advance how to react to it before the client made any expressions. This study has the following significance on a practical and academic level: First of all, counseling through scaffolding further enrich the curiosity, temperament, and wishes of the client. Second, the scaffolding provides a concrete picture of the relationship between a counselor and a client in narrative therapy. Third, the scaffolding made in therapeutic dialogue presents a 'learning tasks'. Fourth, counseling through scaffolding has an active meaning that it can develop the higher mental function of clients in charge. Finally, we presented an application of narrative therapy in Vygotsky's theory through analysis of empirical cases. Based on this information, this study did not simply intend to position the client as a research object in narrative therapy. It is meaningful that they have identified the factors necessary to become the subject of narrative therapy and the role of the counselor in the process. In addition, this study has implications in that it contributed to the expansion and substantialization of the research scope of narrative therapy in that it utilized the concept of scaffolding, which has not received much attention in the domestic research.

• Explosives and Blasting
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• v.24 no.2
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• pp.83-91
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• 2006

Over the past few decades, blasting vibration has been mainly analysed to understand characteristics of far field vibration in the area comparatively far from blast hole in the respect of proving limit of building damage. However, over the last few years, many works have been carried out to estimate damage within the rock adjacent to a blast hole, especially for the Purpose of over break in tunnel blasting and rock slope stability There are several methods to estimate rock damage, but method of using blast vibration has been mostly used to estimate rock damage. Formerly, to estimate rock damage, method of expecting near field vibration using the characteristics of far field vibration had mainly used but nowadays, it is practically possible to measure near field vibration according to development of monitoring system. A few repels relating to this have been studied aboard, but very little work has been conducted in our country because of difficulty of monitoring and choice of monitoring system. Accordingly, in this Paper, measurements of near field vibration were conducted and wave forms were analyzed and some problems were investigated in measuring system.

• Clinical and Experimental Pediatrics
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• v.45 no.2
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• pp.166-173
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• 2002

Purpose : The aim of this study is to find out the distribution of illness, patterns of medical care utilization and factors determining medical care utilization in elementary school children. Methods : We performed the questionnaires in Gwangju city on 2,036 children of two elementary schools from June 1 to June 30, 1998. Results : The prevalence rate of illness was 32.3%. The distribution of illness was respiratory disease(64.7%), gastrointestinal disease(12.8%), injury & poisoning. The rate of persons having received medical treatment when they were sick, was 89.8%. The selection distribution among various medical facilities was pediatric hospital(46.7%), otolaryngologic hospital(19.8%), pharmacy (13.2%) and internal medicine in the decreasing frequency sequence. The major factors influencing the selection of medical facility were geographic accessibility and good results. The most common reason for the first visit to the pediatric hospital was geographic accessibility. The most common reason for a visit and to otolaryngologic hospital was a good result. The most frequently utilized medical facility for respiratory symptoms and gastrointestinal symptoms was pediatric hospital. The persons influencing the selection of medical facility in the children were mother(73.3%), father( 10.8%), doctor and others in decreasing sequence. The persons answering the questionaire thought that the optimal age of pediatric care was from 0 to 12 years(47.8%), to 10 years(22.4%) and to 15 years(18.5%) in decreasing rate. Conclusion : Other departments instead of pediatrics have treated children. Children have particular growth and development process, which is different to those of adults. So, it is necessary to choose special medical care and adequate medical facilities for children.