• Imaging Science in Dentistry
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• v.30 no.1
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• pp.16-22
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• 2000

Purpose : To evaluate the bone densities measured on copper-equivalent image of cross sectional view of mandibular edentulous premolar area obtained by multifuctional panoramic x-ray machine, PM 2002 CC with transversal slicing system. Materials and Methods: Panoramic cross sectional views with 8 mm focal layer of aluminum step and blocks, of hydroxyapatite (RA) step, 6 HA blocks and copper step wedge having 0.03 mm thickness of each step, and of 3 bone blocks cutted by 8 mm thickness mesiodistally and a dry mandible with copper step wedge were taken by using transversal slicing system in PM 2002 Cc. All reference-equivalent images were made and analyzed by NIH image program. Results: The average copper-equivalent value of cancellous bone of bone blocks on the panoramic cross sectional view was 0.026 ± 0.020 mm Cu. The calculated average bone density was 0.38g/cm². There was no significant difference (P>0.1) between the bone densities on intraoral digital view and on the panoramic digital cross sectional view. Conclusion: The copper-equivalent image of panoramic digital cross sectional view obtained by PM 2002 CC with very thin copper step wedge was supposed to be useful to measure the bone density of cancellous bone of mandible at the premolar edentulous area.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.3
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• pp.708-714
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• 2015

The students who learn the computer languages think it very difficult to program using the text-based programming languages and also to learn the object-oriented programming. Therefore, we introduce the object-oriented visual programming into the programming education. And, to solve the this problem in the programming education, in this paper, we introduce the UML to support the object-oriented modeling and to teach the students using the LabVIEW OOP that supports the object-oriented visual programming. And, we propose to apply it on the embedded programming education. Also, we analyze the educational effect of the proposed education methodology of programming based on the student survey.

• Communications for Statistical Applications and Methods
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• v.14 no.1
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• pp.147-153
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• 2007

In this note, we obtained results related to multiparameter discrete exponential families on considering lattice or semi-lattice in place of N (Natural numbers) in view of Cacoullos-type inequalities via the same arguments in Papathanasiou (1990, 1993).

• Journal of Broadcast Engineering
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• v.13 no.6
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• pp.930-940
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• 2008

This paper proposes a prototype realization of multi-view HD video transport system with synchronized multiplexing over IP networks. The proposed synchronized multiplexing considers the synchronization during video acquisition and the multiplexing for the interactive view-selection during transport. For the synchronized acquisition from multiple HDV camcorders through IEEE 1394 interface, we estimate the timeline differences among MPEG-2 compressed video streams by using global time of network between the cameras and a server and correct timelines of video streams by changing the time stamp of the MPEG-2 system stream. Also, we multiplex a selected number of acquired HD views at the MPEG-2 TS (transport stream) level for the interactive view-selection during transport. Thus, with the proposed synchronized multiplexing scheme, we can display synchronized HD view.

• Journal of KIISE:Software and Applications
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• v.26 no.10
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• pp.1156-1166
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• 1999

의사결정 시스템은 전사적인 의사결정과 전략적 정보수집을 위해 거대한 량의 정보를 빠른 시간내에 제공할 것을 요구한다. 데이타 웨어하우스는 이러한 정보를 신속히 제공하기 위해 여러 지역 데이타베이스로부터 필요한 정보를 사전에 추출하고 가공 및 통합하여 별도의 저장공간에 저장한다. 일반적으로, 웨어하우스 내의 정보는 지역 데이타베이스에 저장된 정보에 대한 실체화된 뷰로서 간주하며 지역 데이타의 변경에 따라 일관성을 유지하도록 반영해야 한다. 본 논문에서는 일관성을 유지하기 위해 정보 공유가 가능한 데이타 웨어하우스 시스템의 구조와 비-보상 실체 뷰 관리 기법을 제안한다. 본 논문에서 제안한 데이타 웨어하우스 시스템의 구조는 지역 데이타베이스에서 추출된 정보를 관리하는 별도의 지역 정보 관리자를 두어 뷰 관리자들 간의 정보 공유가 가능하게 한다. 비-보상 실체 뷰 관리 기법은 지역 데이타 변경 사건에 따른 뷰 관리 시 다른 사건에 의해 영향을 받지 않도록 하기 때문에 기본의 사전 보상이나 나중 보상 기법과는 달리 추가적인 질의 처리를 요구하지 않는 기법이다.Abstract A decision support system(DSS) commonly requires fast access to tremendous volume of information. A data warehouse is a database storing the information that is extracted, filtered and integrated from several relevant local databases to reply upon aggregated queries. The information stored in the data warehouse can be regarded as materialized views. The materialized view has to be modified according to the change of the corresponding local databases to preserve the data consistency. In this paper, we propose a data warehousing system architecture allowing information sharing (DAWINS), and a non-compensating materialized view maintenance algorithm(NCA). DAWINS architecture allows relevant information to be shared by individual view managers with local data manager for each local database. Unlikely to the pre- or post-compensating algorithms, which are required to remove the effects of some events to other view in the process of view maintenance, NCA does not require any additional query processing, since a local data manager in DAWINS already maintains the effects of update events occurring in local systems.

• Journal of The Korean Association For Science Education
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• v.17 no.2
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• pp.119-125
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• 1997

In the last few years, there has been a significant growth of interest in how the philosophy of science can be related to science education. Adequate understanding of the philosophy and history of science can promote understanding of the nature of science in teacher and student. The 6th curriculum in Korea has also placed emphasis upon understanding of the nature of science. From this point of view, to ensure effective school science education it is necessary to investigate how teachers and students are understanding the nature of science. To do this 45 secondary science teachers and 191 students of 7 schools in Seoul are administered Nott and Wellington's questionaire(1993). This questionaire is consisted of 24 Likert Scale statements and asks questions on 5 subscales of philosophy of science :Relativism-Positivism, Inductivism-Deductivism, Contextualism-Decontextualism, Instrumentalism-Realism, Thinking science education as a Process or a Content. The results of this study are as follows : 1. Teachers' view of the nature of science was relativism, deductivism, decontextualism and instrumentalism. And they thought process is more important than content in science education. 2. There was no difference in teachers' conceptions on the nature of science according to experience and gender. 3. Students' view of the nature of science was relativism, deductivism, decontextualism and instrumentalism. And they thought process is more important than content in science education. 4. There was no difference in students' conceptions on the nature of science according to schools level(middle vs high) and gender. But, female students exhibited higher score than male students on deductivism(p<.05). 5. Teachers' and students' conception of the nature of science was in agreement with each other.

• Communications for Statistical Applications and Methods
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• v.3 no.2
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• pp.169-174
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• 1996

In the present paper an attempt has been made to improve the Mangat Strategy (1994) in view of the protection of privacy, variance and the range of .pi.. Conditions are obtained under which the proposed model is more efficient than those of warner (1965) and Mangat and Singh(1990).

• Journal of the Korean earth science society
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• v.24 no.2
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• pp.100-107
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• 2003

The purpose of this study is to assess gifted students' conceptions about nature of science (NOS). Scientifically gifted students who are expected to be professionals in the future should possess an adequate understanding of NOS that if firm foundation for scientific career. 47 volunteers from the 8th grade gifted science program in Seoul National University Gifted Education Center participated to answer questions inquiring NOS conceptions. Their answers were analyzed and compared to different groups such as non-gifted students and younger gifted students. As a result, gifted students' understanding of NOS appeared to surpass that of non-gifted students in many aspects and it seemed that gifted students formed their NOS view in early ages. The relative weakness in their NOS conceptions was found in understanding of scientific enterprise. Their strong misunderstanding about obstacles that minority people would face in scientific enterprise was noticed, too. They admitted that there has been discrimination in scientific enterprise, but they wrongly believed that outstanding scientists cannot be affected by it. Further studies will be required to probe more.

• Journal of the Korean Operations Research and Management Science Society
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• v.22 no.2
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• pp.153-167
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• 1997

There have been many studies concerning the relationships between stock returns and volatilities. Their positive relationship is well known from the theoretical point of view, but not empirically shown. Franch, Schwert and Stambaugh [11] has empirically provided the indirect evidence of the positive relationship betwen expected stock return and expected volatility. However, their study lacks some statistical validity. This study reexamines the relationship using regression diagnostics and GARCH model from an international point of view. The empirical results fall to show the positive relationship between expected stock return and expected volaiility, which contradicts those of France, Schwert and Stambangh [1].

• Journal of the Korean earth science society
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• v.31 no.7
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• pp.798-812
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• 2010

The purpose of this study was to investigate beginning teachers' views of scientific inquiry envisioned in science education reform, which is the main goal of science education at schools. Teachers' views about scientific inquiry influence their students' learning in the classroom, so it is significant to investigate teachers' views about the scientific inquiry. 126 beginning science teachers participated in this study. The survey asking teachers' view of general scientific inquiry, nature of science (NOS) and the relationship of science, technology, and society (STS), was developed and implemented for 30 minutes. Alternative views of scientific inquiry including NOS and STS were emerged through data analysis with open coding system. The reliability and validity of data collection and data analysis were constructed through the discussion with experts in science education. The results of this study were as follows. Participants defined scientific inquiry as opportunities of 'Hands-On' and 'Minds-On' or its combination rather than 'Hearts-On'. However, teachers demonstrated the view of 'Hands-On' for the purpose of scientific inquiry and for teachers' roles in its implementation. The view of 'Hearts-On' about scientific inquiry was not identified. The naive view of NOS were identified more than informative one. More positive attitude about the relationship of STS was released. The implication was made in teacher education, especially structured induction program for beginning teachers.