• 한국해양공학회지
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• 제16권1호
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• pp.41-45
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• 2002

This paper is concerned with the erection and ultimate load test of dome shaped space structures by post-tensioning. It is a fast and economical method for constructing such a dome by post-tensioning of the cable in bottom chords. This structure consists of uniform pyramids in a flat layouts on the ground, and then the structure is shaped and erected into its final curved space structure. Ultimate load test was performed for dome shaped space structures. The feasibility of the proposed erection method and the reliability of the established geometric model were confirmed with numerical analysis and experimental investigation on a small scale steel model. As a results we can find the most reasonable modeling technique for the prediction of shape formation in practices and we can know the characteristic of the behaviour in ultimate load test for practical design purposes.

• 국제물리치료학회지
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• 제9권3호
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• pp.1543-1548
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• 2018

The purpose of this study was to analyze the effects of manual therapy on lower extremity alignment in pelvic malalignment. The subjects were 20 adults with pelvic malalignment. They were divided into two groups: manual therapy group (n=10) and stretching exercise group (n=10). Each group performed the intervention two times per week for 4 weeks. The lower extremity alignment was measured by pelvic deviation, functional leg length inequality, and plantar pressure distribution, which were measured between pre- and post-test. In the result of pelvic deviation, there was a significant difference between the pre- and post-test of the manual therapy group and stretching exercise group. In the result of the functional leg length inequality, there was a significant difference between the pre- and post-test of the manual therapy group. In the result of plantar pressure distribution, there was a significant difference between the pre- and post-test of the manual therapy group. These findings suggest manual therapy improves the pelvic deviation, functional leg length inequality, and plantar pressure distribution in the pelvic malalignment.

• 대한치과보철학회지
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• 제38권5호
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• pp.640-649
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• 2000

In the restoration of endodontically treated teeth, carbon fiber post was recently introduced. The purpose of this in vitro study was to investigate the fracture strength of teeth restored with a pre-fabricated carbon fiber post in comparison with teeth restored with a prefabricated titanium post & custom cast gold post after cyclic loading in the different environment. A total of 30 recently extracted human central incisors of similar dimension with crowns removed were used. All teeth were placed into acrylic blocks and every steps for post and core fabrication were made accord-ing to manufacture's instruction. The post length and core dimensions were standardizd. All teeth were divided into 6 groups: 1) carbon fiber post / atmosphere, 2) titanium post / atmosphere, 3) gold post / atmosphere, 4) carbon fiber post / wet, 5) titanium post / wet, 6) gold post / wet. Carbon fiber post and titanium post were cemented in place using resin cement and cores were fabricated with Ti-Core. Custom cast gold post was made from Duralay pattern resin and cemented using resin cement, too. All specimens were thermocycled 10,000 times. After 50,000 cyclic loading, failure strength was measured using Instron testing machine. Kruskal-Wallis test followed by Mann-Whitney test was used to compare the mean fracture strength. Results were as follows : 1. All specimens showed lower fracture strength in wet environment after cyclic loading than in atmosphere condition, but did not reveal a significant difference. 2. There was no significant difference between carbon fiber post specimen and titanium post specimen in the same environment. 3. Gold cast post specimen showed significant different greater fracture strength than those of others in the same environment. 4. Carbon fiber post specimen showed no root fracture.

• 동력기계공학회지
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• 제18권1호
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• pp.106-111
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• 2014

This article describes effect of post heat treatment on wear characteristics of thermally sprayed Co-based self-flux alloy coating. Co-based self-flux alloy coatings were deposited on steel substrates using a flame spray process. Post heat treatments were carried out at 800, 900, 1000 and $1100^{\circ}C$ for 30min in a vacuum chamber. For analysis of effect of post heat treatment on mechanical properties, wear test and hardness test were performed for post heat-treated coating specimen. Microstructures of heat treated coating layer and wear track were examined using SEM and EDS. Wear loss and hardness became lower with increasing post heat treatment temperature.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.165-168
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• 2006

Carbon fiber reinforced polymer(CFRP) have superior mechanical and chemical properties in comparison with conventional materials. And post-tensioning method has been used for structural reinforcement of RC structures due to easy installation and good effect of resisting capacity of structures. But the higher cost of CFRP and the loss of prestressing force with time are considered the major problems to use it. In this study, CFRP Strips and external post tensioning for rehabilitation of old concrete structures were adapted and optimal combination of these methods is considered. A total of 17 concrete members were made and tested. The types and numbers of CFRP strips and post-tensioning types were selected as major test variables. From test results, it is shown that the concrete members that post tensioned and bonded CFRP strips has a pronounced effect on the strength and deformational behavior. This present study indicates that external temporally post tensioning can reduce the amount of CFRP strips required and the combination of temporally post tensioning and CFRP strips may meet the strength and ductility requirements of old structures.

• 대한치과보철학회지
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• 제43권4호
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• pp.415-425
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• 2005

Statement of problem : Fracture of composite resin core will be occulted by progress of crack. Bonding interface of different materials has large possibility of starting point of crack line. Therefore, the bond strength of glass fiber post to composite resin core is important for prevention of fracture. Purpose: This in vitro study tried to find out how to get the higher strength of glass fiber post to composite resin core through surveying the maximum load that fractures the post and cote complex. Materials and methods: 40 specimens made with glass fiber Posts(Style $post^{(R)}$, Metalor, Swiss) and composite resin core ($Z-100^{(R)}$, 3M, USA) were prepared and loaded to failure with push-out type shear-bond strength test in a universal test machine. The maximum fracture load and fracture mode were investigated in the specimens that were restored with four different surface treatments. With the data. ANOVA test was used to validate the significance between the test groups, and Bonferroni method was used to check if there is any significant statistical difference between each test group. Evely analysis was approved with 95% reliance. Results: On measuring the maximum fracture load of specimens, both the treatments of sandblasted and acid-etched one statistically showed the strength increase rather than the control group (p<0.005). The scanning electric microscope revealed that sand blasting made more micro-retention form not only on the resin matrix but on the glass fiber, and acid-etching contributed to increase in surface retention form, eliminated the inorganic particles in resin matrix. Specimen fracture modes investigation represented that sand blasted groups showed lower bonding failure than no-sand blasted groups. Conclusion: Referring to the values of maximum fracture load of specimens, the bonding strength was increased by sand blasting and acid-etching.

• 동서간호학연구지
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• 제13권2호
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• pp.170-178
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• 2007

Purpose: This study was to examine the effects of the Danjeon Breathing Exercise Program on physical fitness, levels of serum lipid and physical symptom of people using public health center at Yangju city. Method: One group pretest-posttest design was utilized for this study. This study has been done from July 6 to September 28, 2005 and the subjects of the study were 28 persons. Danjeon breathing exercise was carried out for 60 minutes a day, 3 times a week for 12 weeks. Physical fitness was measured using the Health Management System developed by the Korea Physical Science Institution. Serum lipid level was measured in public health center at Yangju city. Questions of physical symptom (35 items) were chosen from Cornell Medical Index. The collected data were processed by using the SPSS PC program and analyzed by using Wilcoxon Signed Rank Test. Result: 1. The scores of back strength, flexibility and balance of post-test were more increased after Danjeon breathing exercise than those of pre-test. But the score of muscular endurance of post-test was not significantly increased. 2. The degrees of total cholesterol, LDL-cholesterol and triglyceride of post-test were more decreased after Danjeon breathing exercise than those of pre-test. But the degree of HDL-cholesterol of post-test was not significantly increased in statistics. 3. The score of physical symptoms of post-test was not significantly decreased in statistics after Danjeon breathing exercise than that of pre-test. Conclusion: It is concluded that the Danjeon Breathing Exercise Program could increase the physical fitness and decrease levels of serum lipid. So Danjeon breathing exercise could be utilized to promote physical fittness and to decrease level of serun lipids.

• 대한지역사회영양학회지
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• 제4권3호
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• pp.394-402
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• 1999

The purpose of this study is to investigate diet quality and changes in nutrient and food intake with increase in age. Subjects were 69 patients(28 males, 41 females) living in Jeon-ju city, over middle-aged, and they were the same patients studied 4-7 years ago in a previous study. Dietary survey with one day 24-hour recall method was used. Energy, calcium, vitamin A and vitamin B$_2$intakes were lower than the RDA and vitamin C was in excessive status in pre-test and post-test. In food groups examrned, the consumption of potatoes, beans, vegetables, seaweeds, beverages, seasonings, oils, fish & shells and milks was increased amount than 4-7 years before but the consumption of cereals(p<0.01), sugars, seeds, fruits, processed food, meats and eggs was decreased. Diet quality was assessed by %RDA, nutrient adequacy ratio(NAR), mean adequacy ratio(MAR), dietary diversity score(DDS), meal balance and food group pattern. In %RDA, those proportion of appropriate intake in post-test in were higher than those in pre-test. For most nutrient except vitamin A, the levels of NAR in post-test were higher than in pretest. The MAR, an index of overall dietary quality, was 0.77 for pre-test and 0.83 for post-test(p<0.05). When we counted the major food groups consumed(KDDS), 62.3% of subjects had a KDDS of 3 in pre-test and 42.0% of subjects had a KDDS of 4 in post-test. Based on these results, in terms of variety and balance, total diet quality was improved with advancing of age.

• 대한수학교육학회지:수학교육학연구
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• 제12권3호
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• pp.371-388
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• 2002

The purpose of this study is to analyze the effects of interaction based on contingent regulation between teacher and underachiever in elementary mathematics. For this purpose, research questions are established as follows; (1) Is there any difference between contingent regulation and natural regulation in mathematics achievement\ulcorner (2) Is there any difference between contingent regulation and natural regulation in affectionate perspective\ulcorner (3) Is there any difference between contingent regulation and natural regulation in adult regulation\ulcorner Two classes of fifth grade Children(10 children) were sampled from an elementary school in city of Daegu. One of them was assigned to the contingent regulation group and the other to natural regulation group. An experiment was conducted for 7 weeks. Two kinds of test instruments were used : pre-test and post-test. The pre-test scores guaranteed that both groups were homogeneous. Post-test was used to identify two effects(research questions (1) & (2)) and the post-test scores were analyzed by t-test. The results were as follows. (1) There was significant difference between contingent regulation and natural regulation in mathematics achievement. This means that experiment group was higher than control group and the interaction effect of contingent regulation was higher in post-test. The self-control indicated in experiment group. (2) There was slightly significant difference between contingent regulation and natural regulation in affectionate perspective. This means that experiment group turned to slightly positioner in post-test. (3) There was significant difference between contingent regulation and natural regulation in adult regulation. In other words, level of contingent regulation changed depending on underachievers' ability but level of natural regulation didn't change. Therefore, I suggest that contingent regulation based on Vygotsky theory would provide effective mathematics education for underachievers in elementary mathematics.

• 대한물리의학회지
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• 제2권2호
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• pp.101-112
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• 2007

Purpose : The purpose of this study was to evaluate influence of sacroiliac joint mobilization on lower extremity muscle strength. Methods : The subjects were consisted of thirty patients who had Leg length inequality(LLI) of more than 10mm(16 females. 14 males) from 21 to 41 years of age(mean aged 24.87). All subjects randomly assigned to sacroiliac joint mobilization group(n=15), control group(n=15). sacroiliac joint mobilization group received sacroiliac joint mobilization about 10 minutes for 3 times per week during 4 weeks period. Control group not received intervention during 4 weeks period. The tape measure method(TMM) was used to measure functional Leg length inequality. Biodex System 3 Pro was used to measure strength of Knee extension & flexion. All measurements of each subjects were measured at pre-test, 2weeks post-test and 4weeks post-test. Results : 1. The LLI of sacroiliac joint mobilization group was significantly reduced according to within treatment period(p<.05), most significantly reduced between pre-test and post-test(p<.05). sacroiliac joint mobilization group significantly more reduced than control group(p<.05). 2. The knee extension strength of sacroiliac joint mobilization group was significantly increased according to within treatment period(p<.05), most significantly increased between pre-test and post-test(p<.05). sacroiliac joint mobilization group significantly more increased than control group(p<.05). 3. The knee flexion strength of sacroiliac joint mobilization group was significantly increased according to within treatment period(p<.05), most significantly increased between pre-test and post-test(p<.05). sacroiliac joint mobilization group significantly more increased than control group(p<.05). Conclusion : sacroiliac joint mobilization can reduce LLI and increased lower extremity muscle strength.