• Structural Engineering and Mechanics
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• 제90권6호
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• pp.591-600
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• 2024

This study investigated the acceleration response and shape change characteristics of a gravity quay wall according to the magnitude of the applied acceleration. The quay wall was defined as a port facility damaged by the Kobe earthquake. Four experimental scenarios were established based on the inclination condition grades, considered to be a significant defect factor in the quay wall. Then, the shaking table test was conducted using scaled-down quay wall models constructed per each scenario. The ground acceleration was gradually increased from the peak ground acceleration (PGA) of 0.1 g to 0.7 g. After each ground acceleration test, acceleration installed on the wall and backfill ground and inclination on the top of the wall were measured to assess the amplification of peak response acceleration and maximum response amplitude and the change in the inclination of the quay wall. This study also analyzed the separation of the quay wall from the backfill and the crack pattern of the backfill ground according to PGA values and inclination condition grades. The result of this study shows that response acceleration could provide a reasonable prediction for the changes in the inclination of the quay wall and the crack generation and propagation on the backfill from a current inclination condition grade.

• 한국과학교육학회지
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• 제24권6호
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• pp.1256-1271
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• 2004

최근 학교교육에서 학생들의 과학 태도에 대한 관심과 중요성이 증대되고 있다. 학생들의 과학 태도는 학업 성취도, 교육 프로그램의 일관성, 수업의 질뿐만 아니라 과학 교육의 관점과 과학 관련 직업 선택에도 영향을 준다. 그 동안의 과학 태도에 대한 선행 연구와 국제 비교 연구에 의하면, 우리나라 학생들의 과학 태도는 점차 하락하고 있는 것으로 나타났다. 이 연구에서는 초 중 고 학생들의 과학 태도 변화 과정을 알아보고, 이에 영향을 미치는 학습 환경 변인을 밝히는데 그 목적이 있다. 초등학교 3학년부터 고등학교 2학년 학생 약 6,925명을 대상으로 2003년 3월부터 3회에 걸쳐 학생틀의 과학 태도와 학습 환경 검사를 실시하였다. 분석 결과, 학생들의 과학 태도는 일년 중 6월 이후에 낮아지고, 초등학교 4학년에서 중학교 2학년까지 과학 태도가 크게 변하였다. 과학 태도가 1학기보다는 2학기에 더 많이 하락하였으며, 초 중학교 학생들보다 고등학생들의 과학 태도 하락 폭이 더 컸다. 학생들의 과학 태도에 가장 큰 영향을 주는 요인은 과학에 대한 경험이고, 교사, 학급 분위기 등이 과학 태도 변화에 영향을 주는 것으로 나타났다. 학습 환경 변인은 과학 태도가 하락한 학생과 과학 태도가 상승한 학생이 각각 다르게 영향을 주는 것으로 밝혀졌다. 과학 태도에 영향을 주는 범주는 초등학교에서는 성, 학년, 지역, 중학교에서는 학년과 지역, 그리고 고등학교에서는 지역으로 나타났다.

• 중환자간호학회지
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• 제10권3호
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• pp.9-18
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• 2017

Purpose : This study aimed to identify nurses' job satisfaction, patients' satisfaction, and direct nursing time according to the change in grade of nursing management fee. Methods : Descriptive design was used in this study. Nurses (n = 200) and patients (n = 200) were recruited from one university hospital in Busan. Four aspects were measured: direct nursing time, overtime, nurses' job satisfaction, and patients' satisfaction. Data were analyzed using descriptive statistics, ${\chi}^2-tests$, and t-tests. Results : There was a significant difference in patient satisfaction (t = -2.09, p = .038) and direct nursing time (t = -4.77, p < .001) when the nurse staffing grade was changed from the level two to the level one. Conclusion : The findings from this study showed that a higher nurse-to-patient ratio can provide a greater amount of direct nursing time for individual patients and increase patient satisfaction.

• Nuclear Engineering and Technology
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• 제54권7호
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• pp.2359-2366
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• 2022

Selecting graphite grades with superior irradiation characteristics is important task for designers of graphite moderation reactors. To provide reference information and data for graphite selection, the effects of irradiation on three fine-grained, iso-molded nuclear grade graphites, ETU-10, IG-110, and NBG-25, were compared based on irradiation-induced changes in volume, thermal conductivity, dynamic Young's modulus, and coefficient of thermal expansion. Data employed in this study were obtained from reported irradiation test results in the high flux isotope reactor (HFIR)(ORNL) (ETU-10, IG-110) and high flux reactor (HFR)(NRL) (IG-110, NBG-25). Comparisons were made based on the irradiation dose and irradiation temperature. Overall, the three grades showed similar irradiation-induced property change behaviors, which followed the historic data. More or less grade-sensitive behaviors were observed for the changes in volume and thermal conductivity, and, in contrast, grade-insensitive behaviors were observed for dynamic Young's modulus and coefficient of thermal expansion changes. The ETU-10 of the smallest grain size appeared to show a relatively smaller VC to IG-110 and NBG-25. Drastic decrease in the difference in thermal conductivity was observed for ETU-10 and IG-110 after irradiation. The similar irradiation-induced properties changing behaviors observed in this study especially in the DYM and CTE may be attributed to the assumed similar microstructures that evolved from the similar size coke particles and the same forming method.

• 한국치위생학회지
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• 제9권4호
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• pp.715-725
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• 2009

Objectives : The purpose of this study was to analyze the influence which the professional dental hygiene education has on the knowledge and behavioral change for oral health to the students in the departments of dental hygiene. Methods : 771 students in the first grade and 646 students in the third grade who were attending the departments of dental hygiene from 12 colleges in Korea were surveyed. The self-administered questionnaires were distributed to the students in the colleges during May and asked them to answer the questions and then recovered them on the spot. The collected questionnaires were analyzed by using a SPSS/PC program and the difference of significance depending on the group of the students was tested by Chi-square test or Fisher's exact probability test. Results : In the number of eating snacks by the students during one day, 2-3 times was the highest, irrespectively of the grade. The rate of the students brushing their teeth after snack was higher in the third-grade students(34.8%) than in the first-grade students(20.8%). As the path of acquiring oral health knowledge, all of the first-grade and third-grade students replied that their school classes had impacted them the most. The rate of toothache experience was a higher tendency in third-grade students compared to the first-grade students(p=0.116). The rate of gingival bleeding experience was lower in the third-grade students than in the first-grade students. The rate of oral prophylaxis experience was higher in the third-grade students than in the first-grade students. In the smoking rate, there was lower in the third-grade students than in the first-grade students. The rate of acknowledging smoking hazard to the periodontal health was higher in the third-grade students than in the first-grade students. Conclusions : This study revealed that the third-grade students of dental hygiene departments who were majoring in dental hygiene had a higher perception of oral health than the first-grade students whose the dental hygiene education period was short.

• Perspectives in Nursing Science
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• 제7권1호
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• pp.55-64
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• 2010

Purpose: The purpose of this study was to examine the effects of position change from supine to Fowler's on back pain and discomfort in patients who remained on bed rest after undergoing PCIs with a vascular closure device. Methods: Data was collected from 35 inpatients who were hospitalized in coronary-care unit to perform PCIs with a vascular closure device at S hospital in Seoul from December, 2006 to May, 2007. Back pain, discomfort, presence and grade of bleeding and hematoma from femoral arterial puncture site and blood pressure/pulse rate were measured prior to, 10 minutes, 1 hour and 2 hours after position change. Data was analyzed with descriptive statistics, $x^2$ tests and t-tests using SPSS/WIN 12.0 for Windows program. The level of significance (${\alpha}$) was set at 0.05 for this study. Results: We found that there was no significant difference in back pain and discomfort in 10 minutes after position change between the two groups. However, the experimental group reported significantly less back pain and discomfort than the control group in 1 hour (p<.01, respectively) and 2 hour (p<.01, respectively) after position change. There was no significant difference in the presence and grade of bleeding and hematoma at the puncture site, blood pressure, and pulse rate in 10 minutes, 1hour and 2hours after position change between the two groups. Conclusion: Fowler's position change after PCIs in, therefore, safe and effective method of reducing back pain and physical discomfort without causing additional bleeding and changes in blood pressure and pulse rate.

• 한국초등과학교육학회지:초등과학교육
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• 제25권1호
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• pp.39-50
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• 2006

The purpose of this study was to investigate the effect of metacognitive strategy on conceptual acquisition ofvseasonal change and self-efficacy when it was applied to 6th grade elementary students. This study consists of 2 classes, 76 students in the 6th grade of elementary school, which were divided into the experimental group (38) and the control group (38). First, a pre-test was administrated to check students' levels of metacognitive self-regulation and self-efficacy prior to getting planned lessons and then an instruction program was developed based upon the metacognitive instruction model and students' conception. The control group was exposed to traditional methods mainly using the textbook and teacher's guide book. The experimental group employed a metacognitive learning strategy program and activities with metacognitive questionnaires. After the planned lessons, the students were tested with post-tests about the conception of seasonal change and self-efficacy. One month later the students were tested again with another test to determine the continuation effect. The results were as follows: First, the group that used metacognitive conceptual change instruction did better in forming and continuing to maintain the scientific seasonal change conceptions compared to the control group. Second, the high and intermediate group taught by metacognitive conceptual change instruction was higher in the level of self-regulation than the control group. However, it was not verified in the low group. Third, the group which used metacognitive conceptual change instruction showed a higher level of self-efficacy than the control group did.

• 한국도로학회논문집
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• 제15권4호
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• pp.177-186
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• 2013

PURPOSES: The purpose of this study theoretically reviews vertical grade deriving process in super high speed environment and compares overseas design criteria with Domestic Standardization also draws suitable vertical grade design criteria of high standard for Domestic Circumstances in Korea. METHODS : By researching domestic vehicle registration status, calculating typical vehicle, using Vissim which is traffic simulation program, Speed-distance curve of the vehicle is derived under each design speed condition. Through Speed-distance curve, estimating critical length of grade and considering critical length of grade, maximum longitudinal incline is proposed. RESULTS : The result of domestic vehicle registration status, the typical vehicle for deriving vertical grade is calculated based on gravity horsepower ratio 200 lb/hp. For calculating critical length of grade, according to change speed of uphill entry, speed-distance curve is derived by using Vissim. Critical length of grade is calculated based on design speed 20 km/h criteria which is point of retardation. Estimated critical length of grade is 808 m and based on this result, maximum longitudinal incline was confirmed in the design speed between 130km/h to 140km/h. CONCLUSIONS: The case of the typical vehicle(truck) which is gravity horsepower ratio 200 lb/hp, maximum longitudinal incline 2% is desirable at the super high speed environment in the design speed between 130km/h to 140km/h.

• Korean Journal of Radiology
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• 제1권1호
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• pp.11-18
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• 2000

Objective: To evaluate the hydrodynamic changes occurring in cerebrospinal fluid (CSF) flow in cervical spinal stenosis using the spatial modulation of magnetization (SPAMM) technique. Materials and Methods: Using the SPAMM technique, 44 patients with cervical spinal stenosis and ten healthy volunteers were investigated. The degree of cervical spinal stenosis was rated as low-, intermediate-, or high-grade. Low-grade stenosis was defined as involving no effacement of the subarachnoid space, intermediate-grade as involving effacement of this space, and high-grade as involving effacement of this space, together with compressive myelopathy. The patterns of SPAMM stripes and CSF velocity were evaluated and compared between each type of spinal stenosis and normal spine. Results: Low-grade stenosis (n = 23) revealed displacement or discontinuity of stripes, while intermediate- (n = 10) and high-grade (n = 11) showed a continuous straight band at the stenotic segment. Among low-grade cases, 12 showed wave separation during the systolic phase. Peak systolic CSF velocity at C4-5 level in these cases was lower than in volunteers (p < .05), but jet-like CSF propulsion was maintained. Among intermediate-grade cases, peak systolic velocity at C1-2 level was lower than in the volunteer group, but the difference was not significant (p > .05). In high-grade stenosis, both diastolic and systolic velocities were significantly lower (p < .05). Conclusion: Various hydrodynamic changes occurring in CSF flow in cervical spinal stenosis were demonstrated by the SPAMM technique, and this may be a useful method for evaluating CSF hydrodynamic change in cervical spinal stenosis.

• 기술사
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• 제42권1호
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• pp.44-48
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• 2009

About past 30 years, we don't have enough consideration and investigation about DB-Load. While 30 years, weight of truck is heavier and condition of roads differ, so many conditions of roads and vehicles are changed. We must consider change of many conditions and we must improve laws about maintenance of DB-Load. and now we must consider that low grade as well as high grade bridge can cross heavy vehicle and harmony between changed size of vehicle and bridge while making laws and code. So we can apply to improve design properly.