• Progress in Medical Physics
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• v.23 no.4
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• pp.252-260
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• 2012

The reduction of radiation dose from x-ray is a main concern in computed tomography (CT) imaging due to the side-effect of the dose on human body. Recently, the various methods for dose reduction have been studied in CT and one of the method is a iterative reconstruction based on total variation (TV) minimization at few-views data. In this paper, we evaluated the image quality between total variation (TV) minimization algorithm and Feldkam-Davis-kress (FDK) algorithm in micro computed tomography (CT). To evaluate the effect of TV minimization algorithm, we produced a cylindrical phantom including contrast media, water, air inserts. We can acquire maximum 400 projection views per rotation of the x-ray tube and detector. 20, 50, 90, 180 projection data were chosen for evaluating the level of image restoration by TV minimization. The phantom and mouse image reconstructed with FDK algorithm at 400 projection data used as a reference image for comparing with TV minimization and FDK algorithm at few-views. Contrast-to-noise ratio (CNR), Universal quality index (UQI) were used as a image evaluation metric. When projection data are not insufficient, our results show that the image quality of reconstructed with TV minimization is similar to reconstructed image with FDK at 400 view. In the cylindrical phantom study, the CNR of TV image was 5.86, FDK image was 5.65 and FDK-reference was 5.98 at 90-views. The CNR of TV image 0.21 higher than FDK image CNR at 90-views. UQI of TV image was 0.99 and FDK image was 0.81 at 90-views. where, the number of projection is 90, the UQI of TV image 0.18 higher than FDK image at 90-views. In the mouse study UQI of TV image was 0.91, FDK was 0.83 at 90-views. the UQI of TV image 0.08 higher than FDK image at 90-views. In cylindrical phantom image and mouse image study, TV minimization algorithm shows the best performance in artifact reduction and preserving edges at few view data. Therefore, TV minimization can potentially be expected to reduce patient dose in clinics.

• Journal of Korean Elementary Science Education
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• v.27 no.4
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• pp.420-436
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• 2008

The purpose of this study was to investigate and analysis the elementary teachers' and students' views about the difficulties in teaching and learning in geology units of elementary school science. For the purpose of this study, semi-structured interviews were conducted individually with seventeen elementary teachers who have serviced more than three years, and with sixteen elementary students located in Cheongju City. The interview questions were developed through Seidman's step to acquire a reliability in the interview data with triangulation, then in-depth interview questions were modified and completed through pre-interview after constructing the trustworthiness of interviewees. In-depth interviews were performed in applying the analytic induction method and the interviews were recorded. From the interviews, we found that elementary teachers' views about the difficulties in teaching geology units; teachers' inner difficulties, the difficulty of lab activities, the problems of rock samples, the problems of curriculum in geology units, the difficulty of the geological feature, the problems of the cramming education, the lack of the opportunity for the speciality, and so on. And the students have the views about the difficulties in learning geology units; the difficulty of the unit contents understanding, the problems of learning by heart, the lack of the interest, the lack of materials, the problems of rock samples, the difficulty of the field learning, and so on. Based on the results, the study suggested that an interesting lab activities should be included in the geology units and taught in the geological field trip to help elementary school students more fully comprehend contents of the geology units.

• Annual Conference of KIPS
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• 2000.04a
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• pp.28-35
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• 2000

In order to acquire the precise and fast response for an analytical query, proper selection of the views to materialize in data warehouse is very crucial. In traditional algorithms, the whole relation is considered to be selected as materialized views. However, materializing the whole relation rather than a part of relation results in much worse performance in terms of time and space cost. Therefore, we present a new algorithm for selection of views to materialize using clustering method in order to improve the performance of data warehouse including this problem. In the presented algorithm, ASVMR(Algorithm for Selection of Views to Materialize using Reduced table), we first generate reduced tables in data warehouse using automatic clustering based on attribute-values density, then we consider the combination of reduced tables as materialized views instead of the combination of the original base relations. We also show the experimental results in which both time and space cost are approximately 1.8 times better than the conventional algorithms.

• Journal of The Korean Association For Science Education
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• v.32 no.3
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• pp.428-445
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• 2012

The objective of this study is developing an instrument for investigating views of the respondents on nature of science(NOS) by using experienced scientific knowledge, atomic model. It consists of total six questions and 36 detail items, and each question is reflected the aspects of different NOS which are 'recognition on the model', 'tentativeness of scientific knowledge', 'subjectivity in science', 'use of inference and imagination', 'myths of the scientific method', and 'comparison between science and art'. Particularly, 'comparison between science and art' is addressed almost for the first time in this questionnaire. In the class environment almost not to teach nature of science linking with concrete scientific knowledge, to inquire how the students recognize nature of science, relating to experienced scientific knowledge through this questionnaire will give the data of scientific knowledge based recognition on the nature of science and an important implication for nature of science teaching with concrete scientific knowledge. Developing processes have gone through four steps. In first step, we chose aspects of NOS and developed questions and details. In second step, we tested the draft into fifteen science teachers and, reflecting their opinions, corrected the form and contents of questionnaires. In third step, we tested the questionnaire included writing section for expressing thoughts of the respondents into 55 students in science high school and checked index of coincidence between Likert and open-ended responses which shows 88.2% degree of consensus. Furthermore, to identify the feature of using concrete scientific knowledge we applied this and views on science and education questionnaires together into six university students. We performed final test to 68 university students and measured Cronbach's, and ultimately completed final questionnaire in last step.

• Journal of The Korean Association For Science Education
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• v.38 no.2
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• pp.113-122
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• 2018

The purpose of this study is to investigate the effects of the educational context variables on students' science achievement and interest in TIMSS 2015. TIMSS 2015 science data and questionnaire results were used to fit the Hierarchical Linear Model (HLM) in this study. According to the results, books at home, parents' level of education, and students' views on science lessons have significant influence on science achievement of above-high level 4th-grade students, and books at home on below-intermediate level 4th-grade students. Books at home, students' views on science lessons, and school composition by student economic background have significant influence on science achievement of above-high level 8th-grade students, and books at home and students' views on science lessons on science achievement of below-Intermediate level 8th-grade students. In all grade levels, books at home, and students' views on science lessons have significant influence on science achievement and interest. Discussed in the conclusion are ways to improve science teaching and learning including offering systematic reading programs for all students, reinforcement of student-participation in science classes, connecting science hands-on activities with science concepts for below-Intermediate level elementary students, and so on.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.25 no.2
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• pp.389-398
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• 1995

The purpose of this study was to compare the diagnostic performance of Waters' and panoramic view; maxillary sinus posteroanterior and lateral scanography of Scanora/sup (R)/ for mucosal thickening of maxillary sinus as well as to identify the utility of Scanora/sup (R)/ for the detection of maxillary sinus disease. The assessment was done at 66 maxillary sinuses in 45 patients and the results were as follows ; 1. Estimation of presence or absence of mucosal thickening. The sensitivity, specificity, and positive and negative predictive value of maxillary sinus posteroanterior and lateral scanography were 0.865, 0.860, 0.921, and 0.805 respectively and slightly higher than those of Waters' and panoramic views, which were 0.832, 0.835, 0.903, and 0.728 respectively. However, paired t-test showed no significant differences in the diagnostic performance of the two pairs of imaging modalities. 2. Estimation of the types of mucosal thickening. The diagnostic accuracy for type I, II, III was 75.3％ on Waters' and panoramic view; 77.9％ on maxillary sinus posteroanterior and lateral scanography. It was higher on the latter ,but showed no significant differences from that on the former. 3. Reliability of interpretation. In itraobserver and interobserver agreement, both overall rates of agreement and kappa-value were slightly higher on maxillary sinus posteroanterior and lateral scanography than on Waters' and panoramic views. There was no significant differences between the two pairs of imaging modalities. These results suggested that scanogram is a useful diagnostic radiography as well as Waters' and panoramic views for detection of maxillary sinusitis.

• Journal of The Korean Association For Science Education
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• v.17 no.4
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• pp.501-510
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• 1997

Science teachers' beliefs about science and school science and their perceptions of the science laboratory learning environment were investigated with an assumption that science laboratory teaching would be affected by science teachers' beliefs. Likert-scale questionnaires of BASSSQ and SLEI were used in this study. The major findings were as follows: 1. Science teachers showed inconsistent beliefs about science and school science. Their responses reflected a patch-like view of postmodern epistemology and objectivism They also showed somewhat different views about science and school science. It was found that science teachers had strong objectivist views about science in some parts. but they had moderate constructivist views about school science in other parts; 2. The mean scores of student cohesiveness, integration. and rule clarity on the actual version in SLEl were relatively high, but those of open-endedness and physical environment were very low; 3. There was no association between teachers' beliefs about science and their perceptions of the science laboratory learning environment. But some associations were found between teachers' beliefs about school science and their perception on student cohesiveness, integration, and rule clarity of the actual science laboratory learning environment. Teachers' beliefs about school science had some statistically significant correlations with their perceptions on all scales of the preferred version of SLEI. We could not show a causal relationship between teachers' beliefs and their science laboratory learning environment through these results. But it can be suggested that teachers' beliefs about school science do have a role in constructing a desirable science laboratory learning environment, as we found that there were statistically significant correlations between them.

• Journal of Science Education
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• v.34 no.2
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• pp.246-259
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• 2010

The purpose of this study was to investigate pre-service biology teachers' perception of the evolution. This study was to compare the views of pre-service biology teachers with no religion with those of christian preservice teachers. Subjects were 77 pre-service biology teachers who enrolled in an university and graduate school of education located in Seoul. The instrument of this study was a questionnaire which consisted of 14 items on 2 domains: the nature of science, the origins of human beings. The key results are as follows. Most pre-service teachers showed highly understanding of the characteristics of science. However pre-service biology teachers still possessed naive views on the distinction of law and theory. In terms of the methods of science, many of the pre-service biology teachers considered scientific theories to progress through the accumulation of observation and experiments or through changes and modifications in existing theories. Compared with the pre-service teachers with no religion, christian pre-service teachers had conflicting views and misconceptions about the origins of human beings. The factors of religion were found to be one of the important barriers which prevent them from understanding the origins of human beings. The results suggested that the education program for pre-service biology teachers integrating the concepts and development process of the scientific knowledges should be effective for understanding the nature of science. For pre-service biology teachers, It is important to understand conflicting views of the christian pre-service teachers who understand creationism as a science.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.2
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• pp.500-521
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• 2021

Echocardiography, an ultrasound scan of the heart, is regarded as the primary physiological test for heart disease diagnoses. How an echocardiogram is interpreted also relies intensively on the determination of the view. Some of such views are identified as standard views because of the presentation and ease of the evaluations of the major cardiac structures of them. However, finding valid cardiac views has traditionally been time-consuming, and a laborious process because medical imaging is interpreted manually by the specialist. Therefore, this study aims to speed up the diagnosis process and reduce diagnostic error by providing an automated identification of standard cardiac views based on deep learning technology. More importantly, based on a brand-new echocardiogram dataset of the Asian race, our research considers and assesses some new neural network architectures driven by action recognition in video. Finally, the research concludes and verifies that these methods aggregating dynamic information will receive a stronger classification effect.

• Journal of Science Education
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• v.38 no.1
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• pp.57-77
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• 2014

A longitudinal study traced changes in students' understanding of Nature Of science (NOS) through the public secondary science education in Ontario Canada. Although the concepts of NOS are complicated, and students' understandings are not easy to change, not many longitudinal studies have been done across the world. The current study tried to identify the changes of participating students' understandings of NOS for two and half years of public secondary science education in Ontario Canada. Pretest was administered using Views of Nature of Science (VNOS-C) when six participants graduated from a middle school of Toronto. Two and half years of secondary education, the posttest was carried out using the same instrument. After pre and posttest, probing interviews were performed. The analysis of the data was founded on the Standards and the conceptual framework for this study. The findings were that the initial views have little changed. Most examples and explanations the participants provided were from their science classes. Lab activities for confirming the existing laws and theories and observable photos in science textbooks made students regard the knowledge as a truth. Naturally, their knowledge has been expanded for 2 and 1/2 years, but this expansion of scientific knowledge led students toward Universalist views on science. On the other hand, when science was presented with a historical approach or was networked with other concepts, students acknowledged science and scientific knowledge had been induced from inferences as well as observations and experimental results. Based on the findings the authors of this research suggest that educating the knowledge of science should be historical and networked approaches rather than teaching the knowledge as concise and true statements of the nature.