• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.1
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• pp.73-85
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• 2014

The CFT (Concrete Filled steel Tubes) column-footing connection is cast-in-place embedded type which provides simple construction procedure, low cost, and superior structural performance. In this study, CFT column-footing connection of modular pier is proposed and structural performance is evaluated by experimental tests. To evaluate structural performance of the CFT column-footing connection, a series of experimental tests were performed for the 4 specimens with different embedded depth. As a result of the quasi-static test, the specimen with 0.6D (0.6 times the outside diameter of steel tube) embedded depth showed relatively low ductility than other specimens with larger embedded depth due to cone failure of base concrete occurred during the lower loading step. On the contrary, cone failure of the base concrete was not observed in the specimens with larger embedded depth than 0.9D, but typical flexural failure in lower part of CFT column was observed. With the analyses of force-displacement curve, displacement ductility, and energy dissipation capacity, it is concluded that the rational range of embedded depth of the CFT column-footing connection is from 0.9D to 1.2D in view of good seismic performance.

• Journal of Korean society of Dental Hygiene
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• v.4 no.2
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• pp.193-207
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• 2004

The aims of the study are as following : First, define and clarify the role and function of the dental hygienist. Second, based on thai definition, present an improved dental hygienist curriculum, improving their special competence. This study seeks to present a way for promoting role of dental hygienists as independent specialists, rather than as auxiliaries, contributing to better dental service in the process. The research was pursued by surveying by questionnaire those directly related to dental hygiene. They are 58 professors of dental hygiene, 164 dentists, 253 dental hygienists and 496 dental hygiene students, selected by the method of simple random sampling. Due to the small size of the sample, professors' group was analysed only through frequency and probabilities. For groups with larger samples(dentists, dental hygienists, dental hygiene students), methods of chi square(${\chi}^2$) tests, frequency analysis and one-way ANOVA were used in their analysis. Conclusions of the study are as following : First, role and function of the dental hygienist was defined and clarified. According to the analysis of the survey, main role of the dental hygienists as perceived by 62.9% of dentists was supporting treatments and managing patients and facility. This perception by dentists differs significantly to perception of other groups, which saw main role of dental hygienists as preventive dental treatment and dental hygiene education. Also, only 20.2% of dental hygienists perceived patients and facility management as their main role. This divergence of perception between groups weakens speciality competence of dental hygienists. To strengthen dental hygienists' speciality competence, preventive dental treatment and dental hygiene education must be defined as main role of dental hygienists. Furthermore, role of dental hygienists can be categorized into cooperative and auxiliary role. Second, in order to strengthen speciality competence of dental hygienists, their education must be augmented with curriculum emphasizing cooperative role. Specifically, courses on preventive dental treatment, dental hygiene education and dental X-ray photography must become compulsory, as well as becoming more comprehensive and organized. Also, training in schools and hospitals must be focused on those subjects. In addition, courses concerning auxiliary role must be incorporated into optional courses and more pedagogical courses are needed to widen students' career choices. Third, practical relevance of national dental hygienist certification examination must be heightened. In the survey, all groups gave negative response to questions concerning practical relevance of national dental hygienist certification test. Specifically, contents of the tests must be changed to test participants' competence in the cooperative area. Also, the test itself must be strengthened by adding practical examination to the certification scheme, as well as having more difficult examinations.

• International Journal of Highway Engineering
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• v.13 no.2
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• pp.103-114
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• 2011

Usage of bicycle has been supported the universal reduction of energy consumption and $CO_2$. For the same purpose, new constructions for long length bike roads are planned in Korea. Recently, laboratory tests of physical properties and resistance against environmental loading about optimum mix design of roller compacted concrete, that have advantages of high structural performance by cement hydration and aggregate interlocking, simple construction procedure and low construction cost, are performed for the effective construction of new bike roads. However, properties of roller compacted concrete had different results between laboratory and field tests since it had different compaction method. Also, construction method of roller compacted concrete are not defined for the application of bike roads since it had different demand performance such as thin pavement thickness, low strength and etc with road pavements. Thus, in this experimental research was launched to evaluate the core properties, visual inspection, compaction ratio, water content, thickness reduction rate of roller compaction, skid resistance and roughness by experimental construction about variable mix proportion and compaction method based on laboratory test results. And construction method of roller compacted concrete pavement were suggested for the application of bike roads.

• Clinical and Experimental Pediatrics
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• v.45 no.3
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• pp.320-324
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• 2002

Purpose : Steatorrhea tests have been developed using various methods. Acid steatocrit is a simple method to detect steatorrhea and has very high sensitivity and specificity. This present study was designed to establish the normal values of acid steatocrit in Korean infants and to find the difference according to the various feeding methods. Methods : Acid steatocrit tests were conducted on 128 infants who were under 12 months of age and who had non-specific gastrointestinal diseases between May 1998 and April 2001. The results were classified into neonatal ages(79 neonates), 1-6 months(28 infants), 7-12 months(21 infants). This included formula-fed(46 neonates) and human milk-fed(33 neonates), 1-6 months formula-fed (18 infants) and human milk-fed(10 infants), 7-12 months formula-fed(11 infants) and human milk-fed(10 infants). Results : The acid steatocrit values decreased by infant age in months. Acid steatocrit values decreased much more after 7 months of ages. The acid steatocrit values of human milk-fed infants were significantly lower than those of formula-fed infants. Conclusion : Our study confirms that a physiologic steatorrhea was found in the infant period and decreases by infant age of months. The acid steatocrit test might be useful for the evaluation of gastrointestinal milk fat malabsorption disorders and therapeutic effects.

• Journal of the Korea Concrete Institute
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• v.18 no.3 s.93
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• pp.389-395
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• 2006

For the assessment of exsiting concrete structures, it is important to get the real strength of concrete. The load test or core test has many problems due to cost time, easiness, structural damage, and reliability and so on. Thus, various non-destructive test and statistical analysis techniques for strength assessment have been developed. As a result the real strength of concrete can be obtained by both direct and indirect test. In this study, a series of experimental tests of core strength and Schmidt hammer tests on 3, 7, 14, 28, 90, 180, 365, and 730 days' were done for predicting the compressive strength of high strength concrete with 65.0MPa of 28-days' strength. Each experimental results was analyzed by simple regression analysis. Then, reliability level and error rate between the proposed equations and the existing ones was examined. However, the application of the exsisting equations was inadequate to high strength concrete, because they were conducted under normal strength concrete. Therefore, the following compressive strength equations were proposed for predicting the compressive strength of high strength concrete by Schmidt hammer test. The proposed equations by Schmidt hammer test are as follows.

• Journal of Mushroom
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• v.13 no.4
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• pp.326-329
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• 2015

This study was carried out to anti-diabetic efficacy of alcoholic extracts in Ganoderma species and Phellinus Baumi. Ganoderma species and Phellinus Baumi. showed inhibitory activity of PTP1B, which acts as negative regulator of diabetes. The ${\alpha}-amylase$ is an important enzyme in the digestion of carbohydrates in the saliva and pancreatic. If inhibition of the enzyme Delaying the digestion rate of the carbohydrate can be reduced postprandial rise in blood glucose levels. The results of the tests the active level that showed a similar inhibition ${\alpha}-amylase$ inhibitory activity and a positive control. Phellinus Baumi. showed the inhibitory activity to 89%, Acarbose as positive control. ${\alpha}-glucosidase$ is an essential enzyme in the digestion and absorption of carbohydrates that break down carbohydrates into simple sugars polysaccharides. The results of the tests the active level that showed a low inhibitory activity. It is thought to be able to complement the shortcomings of conventional anti-diabetic drugs.

• Journal of Yeungnam Medical Science
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• v.8 no.2
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• pp.24-34
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• 1991

Delayed emergence of speech or language are frequent causes for concern about development during early childhood. Dealy in evaluation and proper management until school entry in more likely to result in frustration, anxiety and school failure. Many language disturbances and their attendant behavior disorders respond to intensive language therapy. Authors analyzed the medical recoreds of 52 children with delayed language development evaluated during 30 months from January 1986 through June 1988. The results were as follows : 1. The majority of cases were evaluated at the age of 2-2.9 year old(16 cases, 30.8%) and 3-3.9 year old(11 cases, 21.2%) 2. Male to female ratio was 3 : 1 3. The most common cause was mental retardation(53.8%), followed by developmental language disorder(23.1%) and autism(13.5%) 4. The most common associated condition was dysarticulation(17.3%), followed by strabismus(9.6%) and seizures(7.7%) 5. Special education was recommended in cases of 23(44.2%), speech therapy in 12 cases(23.1%) and consultation to child psychiatry in 7 cases (13.5%). Making diagnosis of underlying disorders is not simple because assessment of intelligence in young children is difficult and only a few tests are standardized. More detailed study on children with delayed language development and development of psychometric tests for the handicapped children are necessary, especially in Korea.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.5C
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• pp.231-238
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• 2012

The rockbolt functions as a main support, which restricts enlargement of the plasticity area and increases stability in the original ground around tunnels, and prevents a second deformation of an excavated surface by supplementing vulnerability arising from opening of the excavated surface. System bolting is generally applied if ground conditions are bad. System bolting is generally installed perpendicular to the excavation direction in every span. If a place is narrow, or it is difficult to insert bolts due to construction conditions, it may be connected and used with short bolts, or installed obliquely. In this study, laboratory model tests were performed to analyze the effect of the ground being reinforced by inclined bolts, based on a bending theory that assumes that the reinforced ground is a simple beam. In all test cases, deflections and vertical earth pressures induced by overburden soil pressure were measured. Total of 99 model tests were carried out, by changing the installation angle of bolts, lateral and longitudinal distance of bolts, and soil height. The model test results indicated that when the installation angle of bolts was less than $75^{\circ}$, deflections of model beams tended to increase rapidly. Also, the relaxed load that was calculated by earth pressure was rapidly increased when the installation angle of bolts was less than $75^{\circ}$. However, the optimum installation angle of inclined bolts was judged to be in the range of $90^{\circ}{\sim}75^{\circ}$. Also, as might be expected, the reinforcement effect of bolts was increased when the longitudinal and lateral distance of bolts was decreased.

• The Journal of Engineering Geology
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• v.20 no.1
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• pp.35-45
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• 2010

The soil tests have been performed on the specimens obtained from about 1,150 sites including landslides and non-landslides areas in natural terrains for last 10 years. Based on the results of those tests, the average soil properties are estimated and the simple equations for estimating permeability are proposed according to geologic conditions. The average permeability in Granite and Mudstone sites is higher than other sites and the content of silt and clay in Mudstone and Gneiss sites is higher than other sites. The correlation analysis and the regression analysis were performed to estimate the coefficient of permeability according to geological conditions. As the result of the correlation analysis, the coefficient of permeability is selected as a dependent variable, and the silt and clay contents, the water contents and the dry unit weights are selected as independent variables. As the result of the regression analysis, the silt and clay contents and the void ratio were involved commonly in the linear regression equations according to geological conditions. To verify the proposed the linear regression equations, the measured result of the coefficient of permeability at other sites was compared with the result predicted with the proposed equations. As the result of comparison, there were a little bit different between them for some data. However the difference was relatively small. Therefore, the linear regression equations for estimating the coefficient of permeability according to geological conditions may be applied to Korean soils. However, these equations should be verified and corrected continuously to improve the accuracy.

• The Mathematical Education
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• v.31 no.2
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• pp.109-119
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• 1992

The primary purpose of the present study is to provide the sources to improve the mathematical problem solving performance by analyzing the effects of the belief systems and the misconceptions of the middle school students in solving the problems. To attain the purpose of this study, the reserch is designed to find out the belief systems of the middle school students in solving the mathematical problems, to analyze the effects of the belief systems and the attitude on the process of the problem solving, and to identify the misconceptions which are observed in the problem solving. The sample of 295 students (boys 145, girls 150) was drawn out of 9th grade students from three middle schools selected in the Kangdong district of Seoul. Three kinds of tests were administered in the present study: the tests to investigate (1) the belief systems, (2) the mathematical problem solving performance, and (3) the attitude in solving mathematical problems. The frequencies of each of the test items on belief systems and attitude, and the scores on the problem solving performance test were collected for statistical analyses. The protocals written by all subjects on the paper sheets to investigate the misconceptions were analyzed. The statistical analysis has been tabulated on the scale of 100. On the analysis of written protocals, misconception patterns has been identified. The conclusions drawn from the results obtained in the present study are as follows; First, the belief systems in solving problems is splited almost equally, 52.95% students with the belief vs 47.05% students with lack of the belief in their efforts to tackle the problems. Almost half of them lose their belief in solving the problems as soon as they given. Therefore, it is suggested that they should be motivated with the mathematical problems derived from the daily life which drew their interests, and the individual difference should be taken into account in teaching mathematical problem solving. Second. the students who readily approach the problems are full of confidence. About 56% students of all subjects told that they enjoyed them and studied hard, while about 26% students answered that they studied bard because of the importance of the mathematics. In total, 81.5% students built their confidence by studying hard. Meanwhile, the students who are poor in mathematics are lack of belief. Among are the students accounting for 59.4% who didn't remember how to solve the problems and 21.4% lost their interest in mathematics because of lack of belief. Consequently, the internal factor accounts for 80.8%. Thus, this suggests both of the cognitive and the affective objectives should be emphasized to help them build the belief on mathematical problem solving. Third, the effects of the belief systems in problem solving ability show that the students with high belief demonstrate higher ability despite the lack of the memory of the problem solving than the students who depend upon their memory. This suggests that we develop the mathematical problems which require the diverse problem solving strategies rather than depend upon the simple memory. Fourth, the analysis of the misconceptions shows that the students tend to depend upon the formula or technical computation rather than to approach the problems with efforts to fully understand them This tendency was generally observed in the processes of the problem solving. In conclusion, the students should be taught to clearly understand the mathematical concepts and the problems requiring the diverse strategies should be developed to improve the mathematical abilities.