• Journal of the Korean Geotechnical Society
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• v.16 no.1
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• pp.75-81
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• 2000

The anisotropy of soils has an important effect on stress-strain behavior. In this study, an attempt has been made to implement artificial neural network model for modeling the stress-strain relationship and predicting the undrained shear strength of normally consolidated clay with varying consolidation pressure ratios. The multi-layer neural network model, adopted in this study, utilizes the error back-propagation loaming algorithm. The artificial neural networks use the results of undrained triaxial test with various consolidation pressure ratios and different effective vertical consolidation pressure fur learning and testing data. After learning from a set of actual laboratory testing data, the neural network model predictions of the undrained shear strength of the normally consolidated clay are found to agree well with actual measurements. The predicted values by the artificial neural network model have a determination coefficient$(r^2)$ above 0.973 compared with the measured data. Therefore, this results show a positive potential for the applications of well-trained neural network model in predicting the undrained shear strength of cohesive soils.

• The korean journal of orthodontics
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• v.35 no.5 s.112
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• pp.371-380
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• 2005

The purpose of this experimental study was to evaluate aㅜd compare maxillary arch dimensional and positional changes between first and second premolar extraction groups. The Calorific Machine was used to illustrate tooth movement in three dimensions. The experimental teeth except the first or second premolars were embedded in artifical alveolar bone. The extraction space was closed using arch wires with bull loops into which 15 degree gable bends were placed. Before and after space closure, radiographs were taken in the sagittal and occlusal directions using occlusal films. The results showed greater mean maxillary incisor retraction and less anchorage loss in the maxillary first premolar extraction group than in the maxillary second premolar extraction group. Mesiopalatal rotation of anchor teeth was greater after extraction of a maxillary second premolar than a maxillary first premolar (P<.001).

• Journal of the Korean Geotechnical Society
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• v.21 no.9
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• pp.25-34
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• 2005

This paper proposes a selection methodology composed of neural network (NN) and genetic algorithm (GA) to design optimal NN structure. We combine the characteristics of GA and NN to reduce the computational complexity of artificial intelligence applications and increase the precision of NN' prediction in the design of NN structure. Genetic selection approach of design parameters of NN is introduced to obtain optimal NN structure. Analyzed results for geotechnical problems are given to evaluate the performance of the proposed hybrid methodology.

• The Journal of the Korean dental association
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• v.24 no.12 s.211
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• pp.1003-1011
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• 1986

총의치 교합에는 관계되는 많은 개념, 기술, 철학이 있다. 이 교합의 기본 법칙들을 이해하고, 어떤 system의 교합이 사용되던 간에 이를 현명하게 잘 적용해야할 것이다. 어떤 교합이, 인공치를 어떻게 배열해야만이 환자에게 가장 안전하면서 효율적인가를 알아내 이를 환자에 적용토록 부단히 노력하는 것이 치과의사의 책임일 것이다.

• The Journal of the Korean dental association
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• v.33 no.3 s.310
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• pp.197-207
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• 1995

• Journal of Technologic Dentistry
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• v.9 no.1
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• pp.51-55
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• 1987

One of the primary advantages of acrylic resin teeth is their ability to bond chemically to the denture base resins. Fracture od acrylic resin teeth from a maxillary denture, however, is not uncommon. Bonding failures have been attributed to faulty boil-out procedures that fail to eliminate all traces of wax from the ridge lap surfaces of the teeth and to contamination of the ridge lap surface by careless application of tinfoil substitute. Attempts to increase the strength of the bond between acrylic resin teeth and heat-cured denture base resin include grinding the glossy ridge lap surface (in fluid system), painting the ridgelap surface of the teeth with monomer-polymer solution, and cutting retention grooves in the ridge lap surface of the teeth. This latter method has been tested by applying a tensile force in a labial direction to the incisal part of the lingual surface of the acrylic resin teeth. A progressive shear compressive load was applied at an angle to the lingual surface of acrylic resin teeth bonded to denture base acrylic resin. No statistically singificant advantage was derived by preparing retention grooves of different shapes in the ridgelap surface of the denture teeth.

• 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.

• 한국해양학회지
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• v.29 no.4
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• pp.383-391
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• 1994

Sea surface height geoidal undulation, and gravity anomaly derived from satellite altimeter measurements are described. Assuming mean sea surface height (MSSH) as geoidal undulation, MSSH was converted to gravity anomaly. the result shows that the gravity anomaly derived from satellite altimeter data can be mapped to an accuracy of the surface ship gravity measurements. The data used for the conversion is the two-year mean sea surface height obtained from GEOSAT Exact Repeat Mission. The conversion was carried out using fast Fourier transform with plane approximation. In this process, the so called remove-restore method was employed.

• Journal of Technologic Dentistry
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• v.1 no.1
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• pp.23-30
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• 1979

• The Journal of the Korean dental association
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• v.12 no.8
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• pp.563-565
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• 1974