• Title/Summary/Keyword: Fixed Sectional Method

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Effect of freezing and thawing on the drainage system for leakage treatment (유도배수공법에서 동결융해의 영향)

  • Kim, Dong-Gyou;Yim, Min-Jin
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.19 no.6
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    • pp.1059-1075
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    • 2017
  • The objective of this study was to evaluate the freezing and thawing resistance of the existing drainage system for leakage treatment of underground concrete structures operating in cold regions. The freezing and thawing test was conducted on 4 types of drainage system specimens to evaluate the freezing and thawing resistance of the drainage system. The freezing and thawing resistance was evaluated on 4 types of Hotty-gel, as a waterproofing material, connection methods and on two methods to fix the drainage board with Hotty-gel on the surface of cement concrete specimen. One cycle of the freeze-thaw testing was 48 hours (24 hours of freezing and 24 hours of thawing), and the temperatures of freezing and thawing were at $-18^{\circ}C$ and $10^{\circ}C$, respectively. Among the 4 types of Hotty-gel connection methods, leakage occurred after 28 cycles (8 weeks) of freeze-thawing only in the Hotty-gel connection method with the 'V' groove applied to the corner of the drainage board. No leakage occurred in the 3 types of Hotty-gel connection methods. In two fixing methods, leakage occurred in the method of fixing the drainage board on the cement concrete specimen using the washer, screw and plastic wall plug. Leakage occurred at one point after 10 cycles (3 weeks) of freezing and thawing. After 28 cycles (8 weeks) of freezing and thawing, leakage point increased to 5 points. As time passed, the leak point was not increased, but the amount of leakage was increased at each leak point. The Hotty-gel connection method with cross-sectional diagonal shape was evaluated to be the highest in the production efficiency considering the production time and manufacturing method of the Hotty-gel connection shape. In the construction efficiency considering the construction time and construction method, the fixing method of air nailer, fixed nail and washer was superior to that of the washer, screw and plastic wall plug.

A STUDY OF THE NORMAL & ABNORMAL OCCULSAL PATERNS IN ADULTS USING THE SUPERIMPOSED RUBBER PATTERN METHOD (Superimposed Rubber Pattern법에 의한 성인 정상 및 비정상 교합자의 교합 양상에 관한 연구)

  • Choi, Dae-Gyun;Lee, Sung-Bok;Kwon, Young-Hyuk;Choi, Boo-Byung
    • The Journal of Korean Academy of Prosthodontics
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    • v.33 no.3
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    • pp.467-491
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    • 1995
  • In order to analyze the occlusin of intercuspation with maximun bite force, fifteen healthy adult subjects with the ages 23 to 27 were studied(Group1 ; 5-normal occlusion with Angle's Class1, Group2 ; 5-Angle's Class2 malocclusion, Group3 ; 5-Angle’s Class3 malocclusion). Head Position was fixed with occlusal plane paralleling to horizontal line and occlusal registration r cord was made with polyether rubber impression material(Ramitec, ESPECo. West Germany). After all subject were trained for maximum intercuspation at least 5 times, occlusal registration procedure was repeated for this study. Lower posterior rubber occlusal registration records were sliced with 1mm thickness using precision metal sliding channel(Hitachi Ind. Co., Japan). Gross sectional drawings were traced from occluding view of upper and lower posterior teeth on the rubber slices using digitizer, and superimposed for the determination of each drawing distance(Superimposed Rubber Pattern Method). Based on superimposed rubber pattern drawings, total area of occlusal view, sum of each area of the 5 divided occlusal contact provinces and its ratio, total area and number of occlusal contact area were determined to elucidate occlusal stability in the normal and abnormal occlusion groups. The data were analysed by t-test(p=0.05) to determine statistical significance. The obtained results were as follows : 1. Group1 showed the largest standard area with occlusal view of the lower posterior teeth and Group3 showed the smallest area. There was a significant difference between Group2 and Group3(p=0.025), and Gropu1 was not statistically different for both Group2 and Group3. 2. Means and ratio of the under 2.0mm area(D) and ratio showed $197.49mm^2$, 59.76% in Group1, $188,69mm^2$, 56.10% in Group2, and $174.23mm^2$, 55.76% in Group3. The results that Group1 has the most area/ratio and Group3 has the least area/ratio can be considered Group1 is the most advantageous for masticatory effective area, and Group3 is the least adnantageous. 3. Means and ratio of the under 1.0mm area(C) were $198.96mm^2$, 42.65% in Group1, 123.06$mm^2$, 46.58% in Group2, and $92.24mm^2$, 29.52% in Group3. These data means that Group1 is the most advantageous in terms of masticatory effective area and Group3 is the least. 4. Means and ratio of the under 0.5mm area(B) were $86.68mm^2$, 26.68% in Group1, $62.98mm^2$, 18.71% in Group2, and $36.44mm^2$, 11.66% in Group3. These can also be considered Group1 is the most advantageous for masticatory effective area and occlusal stability. 5. Means and ratio of the under 0.05mm area(A) were $30.92mm^2$, 9.21% in Group1, $14.31mm^2$, 4.25% in Group2, and $7.59mm^2$, 2.43% in Group3. The area ratio of the each subject group was(4.1) : (1.9) : (1)and the data of the under 0.05mm area has the intimate relationship with inter-group and intra-group data/ratio. 6. First molar showed the most occlusal contact points in all subject group and Group1 showed somewhat uniformly distributed occlusal contact point except first premolar. In Group2, all contact point in posterior teeth showed significantly reduced distribution except first molar. Group3 showed evenly distributed contace points in first and second molars.

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College Students' Attitude toward Body Weight Control, Health-related Lifestyle and Dietary Behavior by Self-perception on Body Image and Obesity Index (대학생의 체형인식과 비만도에 따른 체중조절 태도, 건강관련 생활습관 및 식행동)

  • Chin, Jeong-Hee;Chang, Kyung-Ja
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.10
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    • pp.1559-1565
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    • 2005
  • The Purpose of this study was to investigate college students' attitude toward body weight control, health-related lifestyle and dietary behavior by their perception on body image and obesity index. The subjects were 871 nation- wide college students (330 male and 541 female students) participating in a nutritional education program via internet- A cross-sectional survey was conducted using a self-administered questionnaire via internet. The data were analyzed by a SPSS 10.0 program. Height and weight (p < 0.05), and the distribution of obesity index (p < 0.001) showed significant differences between male and female college students. As for self perception on body image, the necessity of body weight control and the experience of efforts to change the body weight, there were significant differences between male and female college students (p < 0.001). There were significant differences among groups by obesity index in the hours of exercise (p < 0.01), drinking (p < 0.01) and smoking (P < 0.001). As for methods of body weight control, all the groups by obesity index thought that program of body weight control by diet company is the most desirable method. Therefore, we must recognize that it is hard to correct health problems resulting from wrong lifestyle and dietary behavior fixed during college life and prepare a system for college students to obtain correct lifestyle and dietary behavior.