• The Mathematical Education
• /
• v.58 no.3
• /
• pp.337-346
• /
• 2019

The purpose of this paper is to investigate the differences of the mathematics anxiety and mathematical achievement of high school students according to gender and grade, and to find out which mathematics anxiety causes have more influence on mathematical achievement and how much it is. The subjects of this study consist of 459 students selected for a class of unit, in high schools located in Seoul, Korea. Huh(1996)'s Mathematics Anxiety Scale was used. The collected data were analyzed by using the 24.0 SPSS program. The data were also tested by using the t-test, correlation and multiple regression. The major results of this study were as follows: Firstly, there was no difference in mathematics score according to gender, but mathematics anxiety was higher in girl students. Mathematics score and mathematics anxiety have significantly related each other. Boy students' mathematics scores were significantly explained by interest, Mathematical Achievement factor, and mathematical confidence factor. For girl students, mathematics achievement factor, interest were the significant predictors. Secondly, mathematical anxiety and mathematics scores were correlated in the first and third grades, and the variables that predict mathematics scores significantly in all grades were interest.

• International Journal of Contents
• /
• v.15 no.1
• /
• pp.52-57
• /
• 2019

The purpose of this research is to evaluate teachers' perception of Korean's achievement standard-based testing system (ASTS) and its process of implementation, and to propose a method of evaluating students' academic aptitude based on university entrance examinations. The core of the 2015 Revised National Curriculum is asserted by changes in classroom instruction, specifically encouraging students' participation in class based on a new method to evaluate student achievement. A total of 124 teachers in charge of student career counseling in middle and high schools in the Jeonbuk province participated in the study. The schools implementing the new method of ASTS were using 61.6% for unit school cut-off point, as opposed to the existing fixed cut-off point of 38.4%. The teachers understanding of the achievement evaluation method was rated 3.54 on the 5-point Likert scale, implying that they had a relatively good understanding of the method. Some of the challenges associated with reflecting the scores from the new student ASTS include difficulty of comparing scores across schools; grade inflation; advantages and disadvantages associated with the type of high school; and the increased importance of university entrance examination. In the ASTS, the fairness during the evaluation of the high school grades and the consequently the reliability of the evaluation prove worrying. As an ultimate result, selecting students based on university admissions data became untrustworthy. There should be further discussions on how students' achievement obtained from the new ASTS should be applied during the university admission process and how students' academic aptitude can be assessed in order to set a direction for secondary school education.

• Journal of People, Plants, and Environment
• /
• v.21 no.6
• /
• pp.501-514
• /
• 2018

This study aimed to develop a program that can be linked to gardening education activities in elementary students' curriculums and creative experience learning courses, and to apply the developed program to 6th graders in an elementary school located in Seoul. Research was conducted in a large category called biophilia, which named the instinct of human nature and nature throughout the research. The curriculum revised in 2015 was selected for the purpose of the garden education program based on the objectives and contents of the unit, and for the purpose of the class. In the process of developing and implementing the program, experience properties and elements were divided into direct and indirect experience of nature, including shapes and forms found in nature, air, water, plants, weather, animals, and natural materials. The results showed that the biophilic horticultural education program was effective in promoting students' multi senses. In the case of the experimental group, all the multi-sensory areas showed statistically significant differences, especially in the area of environmental literacy, environmental effect and emotional balance including plant cultivation knowledge. There was a relatively smaller difference in the dietary effect area than other areas because of no directional dietary program was included in the developed program. As a result, first, it is expected that the data can be utilized on site as a program or place of activity for students in upper grades. Second, it will be necessary to develop a more diverse program using other biophilic elements that were not covered in this study in order to maximize the effects of biophilic education.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.23 no.7
• /
• pp.933-940
• /
• 2017

Draught and trim conditions are highly related to the loading condition of a vessel and are important factors in predicting ship manoeuverability. This paper estimates hydrodynamic coefficients from sea trial measurements with three different trim and draught conditions. A mathematical optimization method for system identification was applied to estimate the forces and moment acting on the hull. Also, fast time simulation software based on the Rheinmetall Defense model was applied to the whole estimation process, and a 4,500 Twenty-foot Equivalent Unit (TEU) class container carrier was chosen to collect sets of measurement data. Simulation results using both optimized coefficients and newly-calculated coefficients for validation agreed well with benchmark data. The results show mathematical optimization using sea measurement data enables hydrodynamic coefficients to be estimated more simply.

• Journal of the Society of Disaster Information
• /
• v.15 no.3
• /
• pp.402-408
• /
• 2019

Purpose: The study want to verify application the medium expantion foam extinguisher of expantion foam rate and fire extinguishing Performance test because the medium expansion system can maintain the discharge distance less affected by air currents, and the foam agent can be used efficiently. Method: For the study, the medium-expansion testing apparatus was manufactured and with synthetic surfactant foam agent of (class B) fire extinguishing model, and Fire Performance was analyzed for foam expansion rate and the fire agent consumption was measured and analyzed. Results: We measured the medium-spray testing apparatus and found that the expansion rate was 26.1 times. The test results of a 20-unit fire extinguishing model show that the extinguishing time is faster than the high and low foam expansion. It has been analyzed that it is possible to apply a hand-operated with a hose reel or medium expansion apparatus. Conclusion: Considering that the foaming agent and the extinguishing performance of the medium foam ratio are excellent, It is necessary to introduce the technical standards of medium foam agent for the introduction of hand-operated equipment, such as hose reel or portable medium foam apparatus.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.47 no.6
• /
• pp.438-445
• /
• 2019

In this paper, we present a new approach to extract the g-sensitivity scale-factor error for a MEMS gyroscope. MEMS gyroscopes, based on the use of both angular momentum and the Coriolis effect, have a g-sensitivity error due to mass unbalance. Generally, the g-sensitivity error is not considered in general use of gyroscopes, but it deserves our attention if we are to develop for tactical class performance and reliability. The g-sensitivity error during vehicle flight increases navigation error; so it must be analyzed and compensated for the use of MEMS IMU for high dynamics vehicle systems. Therefore, we analyzed how to extract the g-sensitivity scale-factor error from the inertial sensor error model. Furthermore we propose a new method to extract the g-sensitivity error using flight motion simulator. We verified our proposed method with experimental results.

• Journal of the Society of Naval Architects of Korea
• /
• v.58 no.4
• /
• pp.225-233
• /
• 2021

Conventional submarine propulsion batteries have mainly used lead acid batteries, which have proved relatively safe, but in recent years, research on mounting lithium-ion batteries to improve the underwater operation capability of submarines is underway in advanced countries such as Japan. Korea has world-class technology in the development of electric vehicles and lithium-ion batteries for energy storage, but fire safety accidents continue to occur in electric vehicles and energy storage lithium-ion batteries. In order to mount the lithium-ion battery in a submarine, it is necessary to check the safety as well as whether the performance is improved compared to the lead acid battery. Through the charge/discharge experiment of this lithium-ion battery module unit, it was possible to measure how much performance was improved compared to the lead acid battery. Safety tests were conducted on the lithium-ion battery module assuming that it was mounted on a submarine, and it was confirmed that safety was secured when applied to a submarine. Since many modules are mounted on actual submarines, it has been confirmed that it can be applied to submarine systems by simulating charge/discharge characteristics through Hardware-in-the Loop(HILS). Through the results of this study, the application of lithium-ion batteries to submarines is expected to significantly improve the sustainability of underwater operations.

• Journal of muscle and joint health
• /
• v.28 no.1
• /
• pp.18-29
• /
• 2021

Purpose: This study examined the knowledge and education needs of nurses in charge of adequacy evaluation in small and medium-sized hospitals. Methods: Study participants included 198 nurses in charge of adequacy evaluation in small and medium-sized hospitals. Data were collected from November 19 to 28, 2020 through an online survey. The data were analyzed by independent t-test and one way ANOVA analysis using the SPSS. Results: The knowledge score for the adequacy evaluation of small and medium-sized hospitals was 11.61±4.10 (total of 20 points), and the educational demand was 3.87±0.88 points on a 5-point scale. Regarding the necessity of education for adequacy evaluation of small and medium-sized hospitals, 80.3% of the participants claimed education as being necessary. "Online video lectures" were the most preferred (22.7%) education method, and "2 times" was the most frequent education (47.0%); "1 hour" was the usual duration of class (48.5%). Conclusion: It is necessary to develop and apply an educational program reflecting the measure of educational needs to improve the knowledge level of nurses in charge of adequacy evaluation in small and medium-sized hospitals.

• The korean journal of orthodontics
• /
• v.51 no.1
• /
• pp.43-54
• /
• 2021

Objective: To investigate the cephalometric predictors of the future need for orthognathic surgery in Korean patients with unilateral cleft lip and palate (UCLP) despite long-term use of facemask with miniplate (FMMP). Methods: The sample consisted of 53 UCLP patients treated by a single orthodontist using an identical protocol. Lateral cephalograms were taken before commencement of FMMP therapy (T0; mean age, 10.45 years), after FMMP therapy (T1; mean age, 14.72 years), and at follow-up (T2; mean age, 18.68 years). Twenty-eight cephalometric variables were measured. At T2 stage, the subjects were divided into FMMP-Nonsurgery (n = 33, 62.3%) and FMMP-Surgery (n = 20, 37.7%) groups according to cephalometric criteria (point A-nasion-point B [ANB] < -3°; Wits-appraisal < -5 mm; and Harvold unit difference [HUD] > 34 mm for FMMP-Surgery group). Statistical analyses including discrimination analysis were performed. Results: In FMMP-Surgery group, the forward position of the mandible at T0 stage was maintained throughout the whole stages and Class III relationship worsened with significant growth of the mandibular body and ramus and counterclockwise rotation of the maxilla and mandible at the T1 and T2 stages. Six cephalometric variables at T0 stage including ANB, anteroposterior dysplasia indicator, Wits-appraisal, mandibular body length, HUD, and overjet were selected as effective predictors of the future need for surgical intervention to correct sagittal skeletal discrepancies. Conclusions: Despite long-term use of FMMP therapy, 37.7% of UCLP patients became candidates for orthognathic surgery. Therefore, differential diagnosis is necessary to predict the future need for orthognathic surgery at early age.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.24 no.1
• /
• pp.100-108
• /
• 2021

Purpose: Percutaneous endoscopic gastrostomy (PEG) tube placements are commonly performed pediatric endoscopic procedures. Because of underlying disease, these patients are at increased risk for airway-related complications. This study compares patient characteristics and complications following initial PEG insertion with general endotracheal anesthesia (GETA) vs. anesthesia-directed deep sedation with a natural airway (ADDS). Methods: All patients 6 months to 18 years undergoing initial PEG insertion within the endoscopy suite were considered for inclusion in this retrospective cohort study. Selection of GETA vs. ADDS was made by the anesthesia attending after discussion with the gastroenterologist. Results: This study included 168 patients (GETA n=38, ADDS n=130). Cohorts had similar characteristics with respect to sex, race, and weight. Compared to ADDS, GETA patients were younger (1.5 years vs. 2.9 years, p=0.04), had higher rates of severe American Society of Anesthesiologists (ASA) disease severity scores (ASA 4-5) (21% vs. 3%, p<0.001), and higher rates of cardiac comorbidities (39.5% vs. 18.5%, p=0.02). Significant associations were not observed between GETA/ADDS status and airway support, 30-day readmission, fever, or pain medication in unadjusted or adjusted models. GETA patients had significantly increased length of stay (eβ=1.55, 95% confidence interval [CI]=1.11-2.18) after adjusting for ASA class, room time, anesthesia time, fever, and cardiac diagnosis. GETA patients also had increased room time (eβ=1.20, 95% CI=1.08-1.33) and anesthesia time (eβ=1.50, 95% CI=1.30-1.74) in adjusted models. Conclusion: Study results indicate that younger and higher risk patients are more likely to undergo GETA. Children selected for GETA experienced longer room times, anesthesia times, and hospital length of stay.