• 대한기계학회논문집B
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• 제24권11호
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• pp.1535-1539
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• 2000

A sonic nozzle is used as a reference flow meter in the area of gas flow rate measurement. The critical pressure ratio of sonic nozzle is an important factor in maintaining its operating condition. ISO9300 suggested the critical pressure ratio of sonic nozzle as a function of area ratio. In this study, 13 sonic nozzles were made by the design of ISC9300 with different half diffuser angles of 2。 to 8。 and throat diameters of 0.28 to 4.48 mm. The test results of half diffuser angles below 8。 ar quite similar to those of ISO9300. On the other hand, the critical pressure ratio for the nozzle of 8。 decreases by 5.5% in comparison with ISO9300. However, ISO9300 does not predict the critical pressure ratio at lower Reynolds numbers than 10(sup)5. Therefore, it is found that it is a better way for the flow of low Reynolds number to express the critical pressure ratio of sonic nozzle as a function of Reynolds number than area ratios. A correlation equation of critical pressure is introduced with uncertainty $\pm$3.2 % at 95% confidence level.

• 대한디지털의료영상학회논문지
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• 제14권1호
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• pp.21-29
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• 2012

The purpose of this study is to evaluate the mutual relations by measuring SNR from T2 weighted image and ADC values on the basis of the stiffness values from liver tissues. This study was conducted that total 37 people(23 of males and 11 of females) were taken the liver MRI examination and average age was $54.5{\pm}12.7$ years old. The equipment was MAGNETOM Skyra 3.0T (SIEMENS, Erlangen, Germany) and 32 channel body-array coil. The examination were conducted with HASTE T2 weighted image by axial plane, Spin-echo EPI (echo planner image) DWI (b-value = 800) and Magnetic resonance elastography. The ROIs (region of interest: 200-300 $mm^2$) were established on the basis of the first axial stiffness image corresponded 95% confidence interval from axial stiffness image and then were measured values. After drawing the grid lines, signals were measured SNR from T2 weighted image and ADC values on the same locations that were analysed other 3 planes respectively. The results were showed correlation (0.057) that were increased to SNR from T2 weighted image by increasing stiffness value that no significant difference statistically p = 0.003. Other results were showed correlations (-0.301) that were decreased to ADC values by increasing stiffness values that no significant difference statistically p = 0.088. In the 3.0T equipment, the results may be error in much the same fashion as the 1.5T from ADC values by evaluation of fibrosis stage. However, Magnetic resonance elastography would be useful method that is used to diagnose exactly liver fibrosis stages in the 3.0T.

• 영재교육연구
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• 제26권2호
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• pp.389-404
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• 2016

본 연구의 목적은 개념도 연구를 통해 초등 영재학생들의 영재수업에 대한 재미요인에 대한 인식을 개념도를 규명함으로써 영재교육 운영의 개선에 도움을 줄 수 있는 자료를 제공하는데 있다. 재미요인 개념도 연구를 위해 수도권에 소재한 단위학교 영재학급 학생 80명을 통해 브레인스토밍을 실시하였고, 그 중 10명을 초점집단으로 하여 분류 평정을 실시하였고, 단위학교 영재학급 학생 140명을 대상으로 개념도 연구를 통해 분석된 재미요인에 대한 동의정도를 구하였다. 연구결과, 개념도 연구를 통해 나타난 재미요인에 대한 최종 진술문은 46개의 문장이었으며 46개의 진술문에 대한 재미 인식 구조는 6가지 하위 범주(영재반 선생님의 격려와 피드백, 자신감과 기회의 획득, 우수한 친구들과의 교류, 알차고 유용하고 뿌듯한 느낌, 새롭고 특별한 실험, 질 높은 수업수준 및 학습환경)로 나타났다. 영재학생들은 재미요인 6가지 중에서 '새롭고 특별한 실험' 요인에 가장 높은 수준으로 동의를 나타냈다. 이 연구의 영재교육 현장에서의 함의가 논의되었다.

• Journal of Preventive Medicine and Public Health
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• 제37권1호
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• pp.11-16
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• 2004

Objective : In this study, we aimed to produce basic data on the prenatal environmental risk factors of low birth weight infants at a community level. Methods : In 2000, we conducted the direct interview using questionnaire about prenatal environmental risk factors with low birth weight infant-delivered mothers and normal weight infant-delivered mothers in Asan-city, Chungcheongnamdo Province, Korea. The questionsgiven to the mothers included past pregnancy history, menstrual status, disease history before and during the pregnancy, family history, environmental risk factors and exposure history. The responses of the twogroups were compared to calculate the prenatal environmental risk factors of each group. Results : Mothers' smoking was significantly associated with low birth weight infants (adjusted odds ratio(AOR) 3.27; 95% confidence interval (CI) 1.25-8.56) and preterm baby (AOR 4.20; 95% CI, 1.21-14.61). Other environmental risk factors were not significantly different between the two groups. Conclusion: Smoking of mothers can be a risk factor for the delivery of low birth weight infants. These results could provide the basic data on prenatal environmental risk factors of mothers of low birth weight infants and suggest research topics for further community-based evaluation.

• Journal of Preventive Medicine and Public Health
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• 제37권2호
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• pp.127-132
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• 2004

Objectives : Cotinine, the major metabolite of nicotine, is a useful marker of exposure to tobacco smoke and self-reporting of smoking status is thought not to be reliable. This study aimed to evaluate the agreement between the smoking self-report among adolescents and the urinary cotinine test. Methods : The study subjects were 1226 middle and high school students in Hanam city, who were selected by stratified random sampling. The self-report about smoking behavior was compared with urine cotinine value measured with PBM $AccuSign^{\circledR}fi$ Nicotine(Princeton BioMeditech Corporation, USA). The percentage agreement, kappa and 95% confidence interval(CI) were calculated. Results : The overall percentage agreement was 88.6%, and those for boys, girls, middle school, general school and vocational school students were 87.3%, 90.1%, 93.7%, 85,5%, 90.7%, and 78.4%, respectively. The overall kappa index was 0.46(95% CI=0.39-0.54)for overall, .and those for boys, girls, middle school, general school and vocational school students were 0.56(95% CI=0.48-0.65), 0.20(95% CI=0.07-0.32), 0.21(95% CI=0.09-0.34), 0.55(95% CI=0.47-0.64), 0.42(95% CI=0.33-0.52), and 0.48(95% CI=0.36-0.60), respectively. Conclusion : The percentage agreement was relatively high but the kappa values very low for girls, and middle school students. Though the prevalence bias can be influenced by these results, the self-report was not a sufficient tool for the evaluation of adolescents' smoking status, especially in girls or middle school students.

• 한국문헌정보학회지
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• 제40권1호
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• pp.315-334
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• 2006

본 연구는 정보활용능력 교육의 효용성을 알아보고자 선정된 실험집단과 통제집단을 통하여 각 집단의 수업전후의 정보활용능력을 측정하였다. 교육 후에 실험집단과 통제집단의 정보활용능력의 차이는 유의한 것으로 나타났다. 정보활용능력 교육의 효과는 각 영역에서 높은 것으로 나타났는데 특히 정보윤리 영역과 정보분석 영역에서 그 효과가 높음을 보였다. 그러나 정보활용능력 교육은 기초환경요인에 영향을 받지 않는 것으로 밝혀졌다. 또한 교육을 수강한 학생들은 정보활용능력에 대한 자신감과 도서관에 대한 인식도가 변화되었다. 이로서 정보활용능력의 교육은 인지적, 태도적 측면 모두 대학생들에게 교양과목으로서 효용성이 높은 것으로 나타났다.

• 한국임상약학회지
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• 제14권2호
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• pp.78-84
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• 2004

Nifedipine, one of calcium channel antagonists, has been used for the treatment of mild to moderate hypertention, angina pectoris, Raynaud's phenomenon and various other cardiovascular diseases. Because of its short biological half-life, several sustained-release (SR) formulations of nifedipine have been developed. and used clinically. The bioequivalence of the two nifedipine SR preparations was evaluated according to the guidelines of KFDA. The test product was Hanmi Nifedipine SR $tablet^{(R)}$ made by Hanmi Pharm. Co. and the reference was Adalat Oros $tablet^{(R)}$ made by Bayer Korea. Thirty healthy male subjects were divided into two groups and a randomized $2\times2$ cross-over study was employed. After one SR tablet containing 33 mg of nifedipine was orally administered, blood sample was taken at predetermined time intervals and the concentrations of nifedipine in plasma were determined using a validated HPLC method with UV detector. Two pharmacokinetic parameters, $AUC_t\;and\;C_{max}$, were calculated and analyzed statistically for the evaluation of bioequivalence of the two products. Analysis of variance was carried out using logarithmically transformed parameter values. The $90\%$ confidence intewals of the $AUC_t\;and\;the\;C_{max}\;were\;log\;0.81\sim1og\;1.19\;and\;log\;0.84\sim\;log\;1.13,\;respectively.$ These values were within the acceptable bioequivalence intervals from log 0.8 to log 1.25 in KFDA guidelines. Thus, the criteria of the KFDA guidelines for the bioequivalence was satisfied, indicating that Hanmi Nifedipine SR tablet is bioequivalent to Adalat Oros tablet.

• 한국임상약학회지
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• 제14권2호
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• pp.85-90
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• 2004

Bisoprolol, one of the $\beta_1-adrenorecepter$ antagonist, has been used for the treatment of mild to moderate essential hypertension anti stable angina pectoris. The oral bloavailability of bisoprolo1 is high $(90\%)$ and the drug has a long elimination half-life, $9{\sim}12\;hr$, which allows once-daily administration. The bioequivalence of two bisoprolol preparations was evaluated according to the guidelines of Korea Food & Drug Administration (KFDA). The test product was Concor $tablet^{(R)}$ made by Newgenpharm and the reference product was Monocor $tablet^{(R)}$ made by Wyeth Korea. Twenty healthy male subjects, 23.8 (21-30) years old and 03.8(52-92) kg, were randomly divided into two groups and a randomized $2\times2$ cross-over study was employed. After two tablets containing 10 mg bisoprolol hemifumarate were orally administered, blood was taken at predetermined time intervals and the concentration of bisoprolol in plasma was determined using an HPLC method with fluorescence detector. Two pharmacokinetic parameters, $AUC_t\;and\;C_{max}$ were calculated and analyzed statistical]y for the evaluation of bioequivalence of the two products. Analysis of variance was carried out using logarithmically transformed parameter values. The $90\%$ confidence intervals of $AUC_t\;and\;C_{max}$ were log $0.95{\sim}1og\;1.04\;and\;1og\;0.96{\sim}1og\;1.07,\;respectively.$ These values were within the acceptable bioequivalence intervals of log $0.8{\sim}log\;1.23$. Thus, the criteria of the KFDA guidelines for the bioequivalence was satisfied, indicating that Concor tablet is bioequivalent to Monocor tablet.

• Transactions on Electrical and Electronic Materials
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• 제17권5호
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• pp.280-288
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• 2016

Microelectronic product consumers may already be expecting another paradigm shift with smarter phones over smart phones, but the current status of microelectronic manufacturing engineering education (MMEE) in universities hardly makes up the pace for such a fast moving technology paradigm shift. The purpose of MMEE is to educate four-year university graduates to work in the microelectronics industry with up-to-date knowledge and self-motivation. In this paper, we present a comprehensive curriculum for a four-year university degree program in the area of microelectronics manufacturing. Three hands-on experienced-based courses are proposed, along with a methodology for undergraduate students to acquire hands-on experience, towards integrated circuits (ICs) design, fabrication and packaging, are presented in consideration of manufacturing engineering education. Semiconductor device and circuit design course for junior level is designed to cover how designed circuits progress to micro-fabrication by practicing full customization of the layout of digital circuits. Hands-on experienced-based semiconductor fabrication courses are composed to enhance students’ motivation to participate in self-motivated semiconductor fab activities by performing a series of collaborations. Finally, the Microelectronics Packaging course provides greater possibilities of mastered skillsets in the area of microelectronics manufacturing with the fabrication of printed circuit boards (PCBs) and board level assembly for microprocessor applications. The evaluation of the presented comprehensive curriculum was performed with a students’ survey. All the students responded with “Strongly Agree” or “Agree” for the manufacturing related courses. Through the development and application of the presented curriculum for the past six years, we are convinced that students’ confidence in obtaining their desired jobs or choosing higher degrees in the area of microelectronics manufacturing was increased. We confirmed that the hypothesis on the inclusion of handson experience-based courses for MMEE is beneficial to enhancing the motivation for learning.

• 대한물리의학회지
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• 제12권4호
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• pp.139-146
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• 2017

PURPOSE: The purpose of this study was to systematically analyze the reliability and validity of the Korean-version of the balance assessment tools. METHODS: Two reviewers of this study independently evaluated the titles of articles and abstracts of studies published until December 2016 through electronic databases (RISS, NDSL, KISS, DBpia) using the keywords "Balance or posture or postural control or postural stability", "Test or assessment or measurement or outcome measure or assessment tool or measurement tool", "Korean version", "Reliability" and "Validity". Regarding the questions considered suitable for the purpose of this study, consensus was reached after reading the full text. Selecting journals suitable for the purpose of the study, they were analyzed as data. RESULTS: The reviewers selected nine papers suitable for the purpose of this study, and Korean-version of the balance assessment tools, included the Berg Balance Scale (BBS), Activities-specific Balance Confidence (ABC) scale, Postural Assessment Scale for Stroke (PASS), Motor Assessment Scale (MAS), Trunk Impairment Scale (TIS), Falls Efficacy Scale (FES), Tinetti-Balance scale, Fullerton Advanced Balance (FAB) scale, and Function In Sitting Test (FIST). Our study showed that the reliability and validity of the Korean-version of the balance assessment tools were high. CONCLUSION: The Korean-version of the balance assessment tools with high reliability and validity would enable physical therapists to make a more accurate evaluation of balance.