• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6C
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• pp.395-406
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• 2006

Drilled shafts are a common foundation solution for large concentrated loads. Such piles are generally constructed by drilling through softer soils into rock and the section of the shaft which is drilled through rock contributes most of the load bearing capacity. Drilled shafts derive their bearing capacity from both shaft and base resistance components. The length and diameter of the rock socket must be sufficient to carry the loads imposed on the pile safely without excessive settlements. The base resistance component can contribute significantly to the ultimate capacity of the pile. However, the shaft resistance is typically mobilized at considerably smaller pile movements than that of the base. In addition, the base response can be adversely affected by any debris that is left in the bottom of the socket. The reliability of base response therefore depends on the use of a construction and inspection technique which leaves the socket free of debris. This may be difficult and costly to achieve, particularly in deep sockets, which are often drilled under water or drilling slurry. As a consequence of these factors, shaft resistance generally dominates pile performance at working loads. The efforts to improve the prediction of drilled shaft performance are therefore primarily concerned with the complex mechanisms of shaft resistance development. The shaft resistance only is concerned in this study. The nature of the interface between the concrete pile shaft and the surrounding rock is critically important to the performance of the pile, and is heavily influenced by the construction practices. In this study, the influences of asperity characteristics such as the heights and angles, the strength characteristics and elastic constants of surrounding rock masses and the depth and length of rock socket, et. al. on the shaft resistance of drilled shafts are investigated from elasto-plastic analyses( FLAC). Through the parametric studies, among the parameters, the vertical stress on the top layer of socket, the height of asperity and cohesion and poison's ratio of rock masses are major influence factors on the unit peak shaft resistance.

• Korean journal of food and cookery science
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• v.17 no.1
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• pp.43-54
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• 2001

This study was to investigate the behavior related to health, food habits, food consumption pattern and nutrient intakes of female students who residing in dormitory(self cooking) according to BMI(Body Mass Index). This study was carried out by questionnaired on June, 2000. Three hundred nine students were answered. The results were as follows: 1. The means of height, weight and BMI were 162.37$\pm$4.36cm, 52.48$\pm$5.54kg and 19.89$\pm$1.89. Under 20 of BMI among students were 53.1% and 20-25 of BMI were 46.9% of students. 2. In the self recognition of body shape, 63.4% of under weight subjects answered that their weight were normal. 73.1% of normal weight regard themselves more obese than their actual body shape normally shows. 51.2% of under weight subjects had attempted to control their weight. This results suggest that their weight control attempts were unnecessary. 3. 81.4% of subjects were answered irregular meals regardless BMI. 89.6% of subjects skipped breakfast. The main reasons were due to lack of time or not to eat proper food. Under weight subjects had less snack than normal weight subjects did(p '||'&'||'lt; 0.05). Normal weight subjects had more bun and cake than under weight subjects(p '||'&'||'gt; 0.05). 4. The consumption of vegetables and fruits were low regardless BMI. Mean energy, protein, Fe, Vit A, B$_1$, B$_2$, niacin, Vit C were above 75% of RDA, except calcium, in subjects. This study suggest that a comprehensive nutrition education program is need for college student in dormitory to improve their eating habits about skipping meal and breakfast and to increase the consumption of vegetables and fruits.

• Journal of the East Asian Society of Dietary Life
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• v.13 no.5
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• pp.391-407
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• 2003

This study was conducted to investigate the factors affecting the born density of food and nutrition major and non-major university students in Seoul area. Data for food habits, dietary and health-related behavior were obtained by self administered questionnaires. BQI(bone quality index) of the subjects were measured by Quantitative Ultrasound (QUS). The results are summarized as follows: The average height, weight, BMI and osteopenia percentage of the major and non-major male and female student were l74.49cm, 67.05kg, 21.96 and 22.0%; l74.34cm, 65.98kg, 21.69 and 11.8%; l60.76cm, 54.48kg, 21.07 and 40.0%; l61.30cm, 54.22kg, 20.84 and 40.2%, respectively. The BQI of the major and non-major subjects were 108.07 and 110.47 in male student group, and 89.13, 88.18 in female student group, respectively. The T-score and Z-score of bone density of the subjects were not significantly different. Weight and BMI were positively related with BQI in male and female group but the relationship with BMI tended to be stronger in non-major female group than other groups. BQI was positively affected by exercise time, favorite food, and intake of seafood and tea in major and non-major male student group. One-side eating habit and intake of instant foods were negatively related with BQI in both male groups. In major and non-major female student group, exercise time, meal regularity, favorite food, amount of meal, intake of tofu were related with BQI positively and intake of tea and/or meats negatively. The result of this study revealed that desirable food habits, dietary behavior and health-related lifestyle may have a beneficial effect on bone density. They need practically and systematically organized nutrition education on optimum body weight, good eating habits, weight bearing exercise and intakes of good quality nutrient for higher bone density level.

• Parasites, Hosts and Diseases
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• v.29 no.3
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• pp.235-244
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• 1991

An epidemiological study and mass treatments of Enterobius vermicularis infection among children near Wonju area of Kangwon province were carried out. The children were divided into 4 groups according to their residing localities; children in the mountainous area, rural area, urban area and in orphanage. They were examined by adhesive cellotape anal swab technique, and egg positive rates were obtained. The rates of egg reduction and re-infection rates after repeated mass treatments were also observed. The results obtained were as follows: 1. The overall egg Positive rate of E. vermicularis in the first screening was 19.9% (251 out of 1, 262 examinees; 19.7% in males and 20.1% in females). The positive rates were 13.0% in the mountainous area, 11 9% in the rural area, 15.1% in the urban (medium-sized) area and 61.9% in orphanages. 2. The highest positive rates were observed in the kindergarten children, and 1st and 2nd grade children of primary schools (26.2~32.2%), and the lowest rate (13.6%) in 6-year grade children of primary schools. 3. Cumulative detection rates from 3 repeated anal swabs at 4~5 days interval were higher (70.8%) than those from single anal swabs (50.0~59.2%). 4. Out of the examinees who showed the highest cumulative positive rate (70.8%), about 39.2% were consecutively positive in 3 anal swabs. Among different groups of children, the higher the total egg detection rates (87.5%), the higher the consecutive positive rates (71.9%) . 5. A total of 2, 609 (male : female=1 : 12.4) worms were collected from 17 egg-positive cases treated with anthelinintics. The mean number of worms per child was 153 (range: 4-824) . 6. The egg-positive cases in several studied groups (180 children) were treated with anthelmintics 6 times at 3-week intervals. In this case, the overall positive rate was decreased from 54.8% to 2.2% at 15 weeks after the treatments, but no complete negative conversion was experienced. However, in a group of children (154 children) including egg Positive and negative cases who were both treated with anthelmintics at 3-week interval, a complete egg-negative conversion was observed in the 9th week after treatments. 7. The egg-detection rate in the brothers or sisters of egg Positive children was 70.0% (28 out of 40 examined), and the egg-positive rate according to the family unit was 69.7%. In summarizing the above results, it is concluded that Enterobius vermicularis infection is still highly prevalent among children in Korea, and that repeated mass treatments of more than 3 times will be effective for control of this infection.