• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.6
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• pp.2700-2706
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• 2013

The purpose of this study was to investigate the casual relationship between school adjustment, self-esteem and life satisfaction and academic achievement in elementary school students. This study utilized the NYPI's longitudinal data collected on elementary school students nationwide for 2012. Equation Modeling analysis was used to analyze 2,254 5th grade students' data. It was found that school adjustment was positively correlated with self-esteem, life satisfaction and academic achievement. School adjustment was directly associated with academic achievement. It was also confirmed that school adjustment indirectly explained academic achievement through self-esteem and life satisfaction. Future research directions and implications to teacher and institutions were discussed.

• Journal of the Society of Naval Architects of Korea
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• v.34 no.4
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• pp.12-20
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• 1997

A potential-based panel method has been developed to investigate the resistance characteristics of a high speed catamaran advancing on the free surface. Normal dipoles and sources are distributed on the body surface while sources are distributed on the free surface. Linearised free surface conditions are used in the present analysis. To avoid the instabilities due to the velocity difference between inner and outer flow of a high speed catamaran, Kutta condition has been applied at the stern. Model test has been carried out not only to validate the numerical results but to confirm the capabilities of a CWC(Circulating Water Channel). It is believed that we can obtain the qualitatively reasonable results in the CWC. Computed results are compared with those of experiments and Insel's experimental values. Since the Kutta condition is applied at the stern, stable solutions are obtained at the high speed range. The present method, using linearised free surface conditions at the high speed range, seems to be a useful tool in the hull form design of a high speed catamaran.

• Journal of Preventive Medicine and Public Health
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• v.17 no.1
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• pp.75-83
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• 1984

A retrospective study has been made of 170,026 cases of motor vehicle accidents which had been reported to the National Police Headquarters of Republic of Korea, 1983. Also a study has been made of 264 cases of road traffic casualties who were treated at the Eul-ji General Hospital from Jan. 1, 1983 to Dec. 31, 1983. This study was conducted to find out the nature and pattern of the traffic accidents from the clinical and epidemiological view points. In additions, the modes of injury from the road accidents were persued which might help to reduce the traffic accident rate. The results of the study were summarized as follows; 1. In this study, the highest incidence was in the age group between $21{\sim}30$ years (21.29%). And the age group of highest death rate was under 10 years (7.28%). 2. In the comparison of sexual differences, male was dominated in accidents number and death rate. (Casualty rate; 61.66%). 3. In the comparison of each hour differences, the accident was mostly occured during afternoon from 16:00 to 18:00(12.23%). 4. The most common day of week was Sunday (14.74%). 5. The most common season of year was Autumn (27.92%). 6. In the comparison of occupational differences, the high incidences were showed in labor men (31.06%) and business men (12.12%). 7. In the comparison of accidental vehicles, the most common vehicle were cars and the next were trucks and buses. 8. The most common mechanism of accidents was collision (57.41%). 9. In the comparison of clinical differences, orthopaedic and neurosurgical injuries were most common types of the hospitalized casualties. 10. In the comparison of anatomical fracture sites, the most common site was tibia (15.81%) and the next site was femur (12.56%).

• Journal of Preventive Medicine and Public Health
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• v.28 no.1 s.49
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• pp.85-101
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• 1995

This study was carried out to evaluate the associations between lifestyles and Body Mass Index in a group of 349 male and 65 female medical students, ages 17 to 31 years. 20.0% of male students and 3.1% of female students showed the over weight in the classification of obesity by Japan Society for Study of Obesity. There was no statistically significance in the comparison of the height, body weight, body mass index, obesity index and body fat(%) according to grade in both sexes. But male students showed increasing tendency of waist-hip ratio with grade. According to obesity category, there was significant difference in the comparison of body weight, body mass index, obesity index, waist-hip ratio and body fat(%), but height. Body mass index was positively related with waist-hip ratio(r=0.6150, p=0.0001) and fat(%)(r=0.5101, p=0.0001) in males and waist-hip ratio (r=0.4734, p=0.001) and fat(%)(r=0.4522, p=0.002) in females. This study provides an opportunity to further examine the relationship of sociddemographic factors and health behaviors to obesity, and suggest the basic concept to match the obesity study to general epidemiological cohort studies for controlling of chronic adult diseases.

• Archives of Plastic Surgery
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• v.35 no.1
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• pp.7-12
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• 2008

Purpose: Since the report of artificial dermis manufacturing method using collagen by Yannas in 1980, collagen has been effectively used as dermal substitute with its merits such as, lower antigeneicity, controllable biodegradation rate, and minimal inflammatory cytotoxic properties in the dermal tissue engineering field. However, weak mechanical durability was the main drawback of collagen dermal substitute. To improve its stability, mechanical or chemical cross-linking was used. Despite of such process, its clinical use was restricted due to weak durability. To improve the durability of collagen matrix, we designed elastin-incorporated collagen matrix and compared its durability with conventional collagen matrix. Methods: 15mm diameter with 4mm thick collagen dermal matrix was made according to Yannas protocol by mixing 0.5% bovine collagen and chondroitin-6-sulfate followed by degassing, freeze drying, dehydrodermal cross-linking and chemical cross-linking procedure. In elastin incorporated collagen matrix, same procedure was performed by mixing elastin to previous collagen matrix in 4:1 ratio(collagen 80% elastin 20%). In comparison of the two dermal matrix in vitro tests, matrix contracture rate, strain, tensile strength, was measured and stiffness was calculated from comparative analysis. Results: In terms of matrix contracture, the elastin-incorperated added collagen dermis matrix showed 1.2 times more contraction compared to conventional collagen matrix. However, tensile strength showed 1.6 times and stiffness showed 1.6 times increase in elastin-incorporated matrix. Conclusion: Elastin incorperated collagen matrix manufactured by our team showed increased durability due to improvement in tensile strength and stiffness compared to previous collagen matrix($Integra^{(R)}$).

• Archives of Plastic Surgery
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• v.41 no.5
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• pp.513-519
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• 2014

Background Currently, breast conservation therapy is commonly performed for the treatment of early breast cancer. Depending on the volume excised, patients may require volume replacement, even in cases of partial mastectomy. The use of the latissimus dorsi muscle is the standard method, but this procedure leaves an unfavorable scar on the donor site. We used an endoscope for latissimus dorsi harvesting to minimize the incision, thus reducing postoperative scars. Methods Ten patients who underwent partial mastectomy and immediate partial breast reconstruction with endoscopic latissimus dorsi muscle flap harvest were reviewed retrospectively. The total operation time, hospital stay, and complications were reviewed. Postoperative scarring, overall shape of the reconstructed breast, and donor site deformity were assessed using a 10-point scale. Results In the mean follow-up of 11 weeks, no tumor recurrence was reported. The mean operation time was 294.5 (${\pm}38.2$) minutes. The postoperative hospital stay was 11.4 days. Donor site seroma was reported in four cases and managed by office aspiration and compressive dressing. Postoperative scarring, donor site deformity, and the overall shape of the neobreast were acceptable, scoring above 7. Conclusions Replacement of 20% to 40% of breast volume in the upper and the lower outer quadrants with a latissimus dorsi muscle flap by using endoscopic harvesting is a good alternative reconstruction technique after partial mastectomy. Short incision benefits from a very acceptable postoperative scar, less pain, and early upper extremity movement.

• Journal of Educational Research in Mathematics
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• v.24 no.2
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• pp.103-124
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• 2014

The process of analogical reasoning can be conventionally summarized in five steps : Representation, Access, Mapping, Adaptation, Learning. The purpose of this study is to develop more detailed model for reason of analogies considering the distinct characteristics of the mathematical education based on the process of analogical reasoning which is already established. Ultimately, This model is designed to facilitate students to use analogical reasoning more productively. The process of developing model is divided into three steps. The frist step is to draft a hypothetical model by looking into historical example of Leonhard Euler(1707-1783), who was the great mathematician of any age and discovered mathematical knowledge through analogical reasoning. The second step is to modify and complement the model to reflect the characteristics of students' thinking response that proves and links analogically between the law of cosines and the Pythagorean theorem. The third and final step is to draw pedagogical implications from the analysis of the result of an experiment.

• School Mathematics
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• v.7 no.4
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• pp.427-444
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• 2005

The Purpose of this study is to explore he mathematical discovery and justification of six 10th grade students through mathematical modeling activities in spreadsheet environments. The students investigated problem situations with a spreadsheet, which seem to be difficult to solve in paper and pencil environment. In spreadsheet environments, it is easy for students to form a data table and graph by inputting and copying spreadsheet formulas, and to make change specific variable by making a scroll bar. In this study those functions of spreadsheet play an important role in discovery and justification of mathematical rules which underlie in the problem situations. In modeling activities, the students could solve the problem situations and find the mathematical rules by using those functions of spreadsheets. They used two types of trial and error strategies to find the rules. The first type was to insert rows between two adjacent rows and the second was to make scroll bars connecting specific variable and change the variable by moving he scroll bars. The spreadsheet environments also help students to justify their findings deductively and convince them that their findings are true by checking various cases of the Problem situations.

• School Mathematics
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• v.8 no.4
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• pp.365-377
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• 2006

This article examines the Korean classroom teachers' perceptions about the 7th national mathematics curriculum for elementary school. Elementary classroom teachers were surveyed using the researcher-made questionnaire (Teacher Perception about Mathematics Curriculum) and 143 teachers completed the questionnaire. The data collected was analyzed by a descriptive analysis. The results revealed that about 67% teachers considered the curriculum was well developed in scope and sequence. However, 43% teachers reported that the teacher's manual should provide clearer explanation instructional strategies to teach the math topics to children. 38(26%) teachers claimed the curriculum contains too much content to teach. 34(24%) of the teachers indicated some contents were developmentally too difficult for their students to understand. The most serious difficulties for the teachers in teaching mathematics was to accommodate individual student's different mathematics abilities, especially accelerated by private lessons at the after school programs.

• Archives of Reconstructive Microsurgery
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• v.13 no.1
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• pp.24-28
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• 2004

The vascularity of a skin island in fibula osteocutaneous free flap often depends on musculocutaneous perforators that find their origin in the proximal peroneal artery. But a potential drawback has been reported on the unreliability of the skin paddle. The perforating vessels to the skin paddle of the fibula osteocutaneous free flap were rarely derived from a common tibio-fibula trunk, an anterior tibial artery and a posterior tibial artery. Previous studies have emphasized total loss of the overlying skin paddle, if the expected perforating vessels are not present. We report here on our experience that the skin paddle of the fibula osteocutaneous free flap was vascularized not by a peroneal artery but a direct branch of the posterior tibial artery. There were no intraseptal nor intramuscular pedicles in the posterior crural septum which connected to the overlying skin island. Therefore, we performed microsurgical anastomoses between distal peroneal vessels of the fibula and the perforating branches of the posterior tibial vessels of the skin paddle. The anastomosed skin paddle was salvaged with a peroneal flow through vascular anastomosis and was transferred to the bone and intraoral soft tissue defects with the fibula graft. The patient had no evidence of vascular compromise in the postoperative period and showed good healing of the intraoral skin flap.