• Journal of The Korean Association For Science Education
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• v.16 no.1
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• pp.61-76
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• 1996

The purpose of this study was to apply the instructional strategies for conceptual change prescribed by Posner et al(1982) to the astronomic content domain taught in the elementary and middle school and to analyze the characteristics of students' knowledge revealed in the test before, during and after the instruction. Also, it was to investigate the intercorrelation of cognitive levels, spatial ability and science achievement. The major findings of this study are as follows: 1. Students had a great variety of misconceptions related to the motion of the moon before the instruction, that is, the phases, the names of phases and the cause of changing phases by the moon's orbit about the earth, the moon's appearance and location at the given time, the relative positions of earth, moon and sun during a lunar eclipse, the cause that a full moon is not at the line of node once a month. In the analysis of students' responses concerning the cause of changing phases of the moon and a lunar eclipse, the results indicate that the great majority of students had rote learning rather than meaningful learning in the middle school. 2. Students' reponses during the instruction concerning the changing phases of the moon and the predictive knowledge about the motions of the earth and the moon were analyzed. 1) According to the results of the test given before and after experiment, after discussion, achievement score of the whole of subjects and groups in both preformal and formal cognitive levels appeared to increase linearly. 2) There was no statistically significant differences of achievement scores before and after experiment, after discussion between preformal group and formal group in cognitive levels. 3. Distribution of achievement scores according to the whole of subjects and groups in preformal and formal cognitive levels shows that there was a statistically significant difference between pretest and posttest. 4. Types of conceptual changes concerning the cause of changing phases of the moon that occurred from pretest to posttest were classified as accommodation, incomplete accommodation, assimilation, no change and no model. Six of the seven students starting instruction with alternative frameworks didn't sustain those alternative models throughout instruction. Five of these six students accommodated completely and the last one partially. Seventy-nine percentage of students taking instruction with fragmental models assimilated correct propositions at the end of the instruction. These results suggest that conceptual change model prescribed by Posner et al(1982) has promised the meaningful learning to students taking with fragmental models, especially in cases where students with misconception enter instruction. 5. High correlation between achievement score of simple-recall items and that of written items in pretest and posttest indicates that the higher students got the score in simple-recall items the better they also performed in written items. However, there was no statistically significant differences among cognitive levels, spatial ability and science achievement in the whole of subjects and groups according to the cognitive levels.

• Journal of Digital Convergence
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• v.15 no.1
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• pp.267-275
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• 2017

The purpose of this study was to evaluate the clinical availability of ankle-brachial index(ABI) according to severity of cardiovascular disease. The subjects of this study were the patients who had ABI in a general hospital. In this study, total 441 patients were enrolled for analysis. Electric medical records were reviewed to investigate the result of ABI and severity of cardiovascular disease measured vessel disease and Gensini score. Collected data were analyzed using SPSS 21.0 program. Subjects with $ABI{\leq}0.90$ and > 0.90 were classified as having abnormal and normal ABI. There were significant differences in vessel disease categorization($x^2=4.731$, p=.030) and Gensini score(t=2.351, p=.019) between two groups. Therefore, ABI is an effective and non-invasive tool for the diagnosis of cardiovascular disease with high severity. ABI is a valuable predictive index of ischemic heart disease.

• Safety and Health at Work
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• v.11 no.1
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• pp.118-124
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• 2020

Background: The poultry industry in Pakistan has flourished since the 1960s; however, there are scarce data regarding the impact of occupational exposure on the pulmonary health of farm workers in terms of years working in the industry. The objective of the present study was to assess the effect of poultry environment on the health of occupationally exposed poultry farmers in countries of warm climatic regions, such as Pakistan. This study will also show the effect of exposure to poultry facilities on the health of poultry farmers in the context of low-income countries with a relatively inadequate occupational exposure risk management. Materials and methods: The lung function capacity of 79 poultry workers was measured using a spirometer. Along with spirometry, a structured questionnaire was also administrated to obtain information about age, height, weight, smokers/nonsmokers, years of working experience, and pulmonary health of farm workers. The workers who were directly involved in the care and handling of birds in these intensive facilities were considered and divided into four groups based on their years of working experience: Group I (3-10 months), Group II (1-5 years), Group III (6-10 years), and Group IV (more than 11 years). The forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and the FEV1/FVC ratio were considered to identify lung function abnormalities. Statistical analysis was carried out using independent sample t test, Chi-square test, Pearson's correlation, and linear regression. Results: Based on the performed spirometry, 68 (86 %) of workers were found normal and healthy, whereas 11 (14 %) had a mild obstruction. Of the 11 workers with mild obstruction, the highest number with respect to the total was in Group IV (more than 11 years of working experience) followed by Group III and Group II. Most of the workers were found healthy, which seems to be because of the healthy survivor effect. For the independent sample t test, a significant difference was noticed between healthy and nonhealthy farmers, whereas Chi-square test showed a significant association with height, drugs, and working experience. Linear regression that was stratified by respiratory symptoms showed for workers with symptoms, regression models for all spirometric parameters (FVC, FEV1, and FEV1/FVC) have better predictive power or R square value than those of workers without symptoms. Conclusion: These findings suggest that lung function capacity was directly related to years of working experience. With increasing number of working years, symptoms of various respiratory problems enhanced in the poultry workers. It should be noted that most of the poultry workers were healthy and young, the rationale being that there is a high turnover rate in this profession. The mobility in this job and our finding of 86% of the healthy workers in the present study also proposed healthy worker survivor effect.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.3 no.2
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• pp.59-64
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• 2010

Purpose: The purpose of this study was to analyze the correlation between medial joint space on Rosenberg view and the degree of ultrasonographic medial meniscal extrusion. Materials and Methods: Three hundred ninety knees with medial joint tenderness examined by ultrasonography were reviewed between January 2009 and May 2010. Medial joint space was divided into Grade I (${\geq}$ 4 mm), Grade II (3~4 mm), Grade III (2~3 mm), Grade IV (1~2 mm) and Grade V (0~1 mm). Then sonographaphic mid-medial extrusion of the medial meniscus was measured in each patient. After dividing into Group A that didn't have large osteophytes (${\geq}$ 3 mm, medial joint at tibia) and Group B that had them, the correlation between the medial joint space and medial meniscal extrusion were analyzed in each group. One-way ANOVA & Scheffe test on the SAS program were used for the statistical analysis (p<0.05). Results: There was a positive correlation between grade of the joint space and medial meniscal extrusion in Group A, but there was no positive correlation in Group B (p<0.05). Conclusion: To the patients who didn't have advanced osteoarthritis, the narrowing of the medial joint space was one of the predictive factors for mid-medial extrusion of the medial meniscus.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.1
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• pp.90-102
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• 2011

Recently, the grade of users using wireless communication services which transmits and re-transmits to the signal via the broadcasting satellite have a variety. However the ships not preparing of H.264 standard devices should not received the realtime data because the broadcasting stations have transmitted the compressed video data through the satellite communication. Therefore this paper proposes H.264 to MPEG-2 transcoding for the ships using MPEG-2 devices. Proposed method improves a speed and object quality in H.264 to MPEG-2 transcoding by analysis features of macroblock modes in H.264. In the Intra mode of P-frame, it proposes new method by computing coincidence proportion after comparing of Intra mode methods of H.264 and MPEG-2. In the Inter mode, it proposes a PMV(predictive motion vector) considering movement of motion vectors in H.264 decoder. we reuses a PMV directly as like the final MV in MPEG-2 encoder and refinements the MV after coincidence ratio comparing of variable motion vectors of H.264 and these of MPEG-2. The experimental results from proposed method show a considerable reduction in processing time, as much as 70% and 67% respectively, with a small objective quality reduction in PSNR.

• Journal of Oral Medicine and Pain
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• v.32 no.3
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• pp.263-272
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• 2007

The purpose of this study was to analyze the nerve damage after tooth extraction and implant surgery, and to establish a predictive model for assessment and management of dysesthesia. In this questionnaire study, the subjects chosen for this study were 276 dentists who answered the questionnaire about dysesthesia after tooth extraction and implant surgery. The analysis of the results consist of the sex and age distribution, affected site, associated symptoms, rate and duration of the recovery. The results are summarized as follows. : 1. There were no significant difference between the sex and the dysesthesia. 2. The most common affected site was the mandibular region. In the group of the implant surgery, 100% affected the mandibular site. The tooth extraction group was 93.2% affected. 3. Pain was one of the most associated symptom with dysesthesia-46.5% of the tooth extraction and 44.8% of the implant surgery. 4. The recovery ratio was 72.3% in the tooth extraction, 71.8% in the implant surgery. Most of them, they recovered in $1{\sim}6$ months. In conclusion, most of dysesthesia may be recovered within 1 year. However, the possibility of persistent dysesthesia should not be neglected. Therefore, practitioners must discuss the possibility of nerve injury with their patients, and include this possibility in the consent forms. Various methods of monitoring recovery of sensation should be considered for objective assessment of prognosis. In addition, immediate referral to orofacial pain specialists can offer the patients an opportunity for more effective and noninvasive treatments.

• Journal of Gastric Cancer
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• v.17 no.4
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• pp.295-305
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• 2017

Purpose: We previously found that the histone methyltransferase suppressor of variegation, enhancer of zeste, trithorax and myeloid-nervy-deformed epidermal autoregulatory factor-1 domain-containing protein 3 (SMYD3) is a potential independent predictive factor or prognostic factor for overall survival in gastric cancer patients, but its roles seem to differ from those in other cancers. Therefore, in this study, the detailed functions of SMYD3 in cell proliferation and migration in gastric cancer were examined. Materials and Methods: SMYD3 was overexpressed or suppressed by transfection with an expression plasmid or siRNA, and a wound healing migration assay and Transwell assay were performed to detect the migration and invasion ability of gastric cancer cells. Additionally, an MTT assay and clonogenic assay were performed to evaluate cell proliferation, and a cell cycle analysis was performed by propidium iodide staining. Furthermore, the expression of genes implicated in the ataxia telangiectasia mutated (ATM) pathway and proteins involved in cell cycle regulation were detected by polymerase chain reaction and western blot analyses. Results: Compared with control cells, gastric cancer cells transfected with si-SMYD3 showed lower migration and invasion abilities (P<0.05), and the absence of SMYD3 halted cells in G2/M phase and activated the ATM pathway. Furthermore, the opposite patterns were observed when SMYD3 was elevated in normal gastric cells. Conclusions: To the best of our knowledge, this study provides the first evidence that the absence of SMYD3 could inhibit the migration, invasion, and proliferation of gastric cancer cells and halt cells in G2/M phase via the ATM-CHK2/p53-Cdc25C pathway. These findings indicated that SMYD3 plays crucial roles in the proliferation, migration, and invasion of gastric cancer cells and may be a useful therapeutic target in human gastric carcinomas.

• Journal of the Korea Institute of Building Construction
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• v.20 no.1
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• pp.83-91
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• 2020

The recent bridge construction projects is demanded more sophisticated risk management measures and loss forecasts to brace for risk losses from an increase in the trend of bridge construction. This study aims to analyze the risk factors that caused the loss of material in actual bridge construction and to develop a quantified predictive loss model, based on the past record of insurance payment by major domestic insurance companies for bridge construction projects. For the development of quantitative bridge construction loss model, the dependent variable was selected as the loss ratio, i.e., the ratio of insurance payout divided by the total project cost, while the independent variable adopted 1) Technical factors: superstructure type, foundation type, construction method, and bridge length 2) Natural hazards: typhoon and flood 3) Project information: construction period and total project cost. Among the selected independent variables, superstructure type, construction method, and project period were shown to affect the ratio of bridge construction losses. The results of this study can provide government agencies, bridge construction design and construction and insurance companies with the quantitative damage prediction and risk assessment services, using risk indicators and loss prediction functions derived from the findings of this study and can be used as a guideline for future basic bridge risk assessment development research.

• Journal of the Korean Chemical Society
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• v.56 no.3
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• pp.371-377
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• 2012

In this study, open inquiry reports of 165 eighth graders in Daegu were analyzed in terms of content area, the types of inquiry hypothesis, and the types of inquiry variables. Before summer vacation, students learned about inquiry process and explored their own inquiry topic for two class hours. During summer vacation, students performed open inquiry including problem selection, designing and performing experiment, data collection, data analysis, and writing report. After the vacation, students submitted their reports, and answered to additional survey regarding the source of inquiry idea, the definition of hypothesis, and the most difficult step of inquiry process. As a result, chemistry was the most dominant content area of the reports and biology and life science were the next. 130 out of 165 reports included inquiry hypotheses, and most of them were predictive hypotheses. In many reports, dependent and independent variables could not be identified because of their ambiguity. However, inquiry variables described in experimental design, which were mostly categorical variables, were clearer than those described in inquiry subject and inquiry hypothesis. The most difficult step of inquiry process for students was to generate an idea for open inquiry.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.9
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• pp.835-842
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• 2016

In Korea, urban railway cars are typically maintained using the strategy of predictive maintenance. In an effort to overcome the limitations of the existing strategy, there is increased interest in adopting the condition-based maintenance strategy. In this study, a novel method is proposed to detect faults in the solenoid valves of the braking system in urban railway vehicles. We determined the key component (i.e., solenoid valve) that leads to braking system faults through the analysis of failure modes, effects, and criticality. Then, an equivalent circuit model was developed with the compensation of the temperature effect on solenoid coils. Finally, we presented how to detect faults with the equivalent circuit model and current signal measurements. To demonstrate the performance of the proposed method, we conducted a case study using real solenoid valves taken from urban railway vehicles. In summary, it was shown that the proposed method can be effective to detect faults in solenoid valves. We anticipate the outcome from this study can help secure the safety and reliability of urban railway vehicles.