• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.2
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• pp.115-131
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• 2000

In the study of craniofacial deformity, it is very important that identifying the factor which can affect the morphology and which is closely related to the morphology, because it can not only improve the comprehension of growth and developmental process but also be applied in growth prediction and treatment modality. Several investigators have already mentioned the characterstics of head posture and airway space in relations to morphologic difference. But it is very meaningful work in clarifying the correlation between morphology, head posture and airway space that observing the change of head posture after morplologic change caused by operation and the change of airway space after same procedure. To investigate above correlation, I selected normal group which is consisted of 43 adults and mandibular prognathism group which is consisted of 47 adults who had been operated by sagittal split ramus osteotomy and were followed up more than 1 year. With their lateral skull radiograghs, reference lines which can evaluate each measuring points and areas without effect of postural change were first determined. And using above reference lines, change of airway space, positional change of tongue and hyoid, change of cranial and cervical angulations were measured. The results obtained from the study were as follows 1. In the change of head posture, the position of tongue and hyoid neighboring to pharynx is more closely related to the reference line of cervical column than to reference line of cranium. 2. After mandibular setback operation, the airway dimension was decreased to 81.6% of preoperative state at 1 month postoperatively and was slightly increased to 89.7% at 1 year postoperatively. 3. Posterior movement of tongue plays important role in decrease of airway dimension and inferior movement of hyoid was closely correlated with posterior movement of tongue. 4. Postoperative anterior movement of mandible, namely, morphologic relapse had correlation with relapse phenomenon of airway dimension. 5. Craniocervical angulation increased postoperatively. Especially in the postoperative early state, there was increased foreward inclination of cervical angulation rather than increase of cranial angulation. But at postoperative 1 year it was observed that cervical inclination was returned to preoperative state and cranial angulation was increased gradually. 6. Increase rate of airway dimension was correlated with the increase of cranial angulation from postoperative 1 month to 1 year. In conclusion, relapse tendency of airway dimension following increase of cranial angulation was found after mandibular setback operation and it is considered that increase of cranial angulation is one of compensatory mechanism in airway maintenance.

• Biomedical Science Letters
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• v.6 no.2
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• pp.119-129
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• 2000

The skin is an organ that has many important roles, including protection against infection, regulation of temperature and fluid loss, and sensory function. Injury to the skin, wound repair normally involves: (1) balanced activity of inflammation, (2) the re-epithelial phase and (3) the matrix formation of remodeling phase. Thus, skin wound healing is a finely controlled biological process involving a series of complex cellular interactions. Laser therapy is being implemented with increasing frequency in medicine. Low intensity laser is one that is capable of producing an energy density so low that any biologic alterations are the result of direct irradiation effect, not thermal events. This study was designed to evaluate the efficacy of low intensity laser therapy on skin wound healing in rabbits. A total of 10 male rabbits (New Zealand White Rabbit), age 8 weeks were used. Skin wound were surgically created dorso-lateral on the flank of 10 rabbits (2$\times$2 cm/damage areas). The experimental animals were treated with 5Hz (830 nm wave length) low-intensity laser (MILTA-01 Model) daily for 10 min (1.6 J/$cm^2$) for 12 days. Control animals were sham treated with the laser head. Laser irradiation animals showed a complete remodeling of the epithelial layer, a positive repair of connective tissues, and enhanced the wound closure rate over time as compared to the control animals. Especially, laser irradiation groups improved fibroblast activity, cellular content, granulation tissue formation, and collagen deposition which is resulted in improving the tensile strength of the wound. These findings suggest that laser photostimulation could accelerate healing of open wound in rabbits, and may be benefit in the treatment of open wound, including decubitis ulcers.

• Progress in Medical Physics
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• v.16 no.1
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• pp.32-38
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• 2005

Impaired processing of facial information is one of the broad ranges of cognitive deficits seen in patients with schizophrenia. The purpose of this study was to elucidate the differences in brain activities involved in the process of facial working memory between schizophrenic patients and healthy comparison subjects. Ten patients with schizophrenia were recruited along with matched healthy volunteers as a comparison group. Functional magnetic resonance imaging (fMRI) was used to assess cortical activities during the performance of a 1-back working memory paradigm using images of neutral faces as mnemonic content. The patient group performed the tasks with reduced accuracy. Group analysis revealed that left fusiform gyrus, right superior frontal gyrus, bilateral middle frontal gyri/insula, left middle temporal gyrus, precuneus and vermis of cerebellum and showed decreased cortical activities in the patient group. On the other hand, an increased level of activation in lateral prefrontal cortex and parietal lobule was observed from the patient group, all in the right hemisphere. A decreased level of activity in the left fusiform gyrus among the patient group implicates inefficient processing of facial information. An increased level of activation in prefrontal and parietal neural networks from the patient group confirms earlier findings on the impaired working memory of patients with schizophrenia.

• Journal of Korean Society of Steel Construction
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• v.19 no.1
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• pp.29-41
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• 2007

Structural design, like other complex decision problems, involves many trade-offs among competing criteria. Although mathematical programming models are becoming increasingly realistic, they often have design limitations, that is, there are often relevant issues that cannot be easily captured. From the understanding of these limitations, a decision-support system is developed that can generate some useful alternatives as well as a single optimum value in the optimization of steel frame structures. The alternatives produced using this system are "good" with respect to modeled objectives, and yet are "different," and are often better, with respect to interesting objectives not present in the model. In this study, we created a decision-support system for designing the most cost-effective moment-resisting steel frame structures for resisting lateral loads without compromising overall stability. The proposed approach considers the cost of steel products and the cost of connections within the design process. This system makes use of an optimization formulation, which was modified to generate alternatives of optimum value, which is the result of the trade-off between the number of moment connections and total cost. This trade-off was achieved by reducing the number of moment connections and rearranging them, using the combination of analysis based on the LRFD code and optimization scheme based on genetic algorithms. To evaluate the usefulness of this system, the alternatives were examined with respect to various design aspects.

• Journal of Korean Society of Steel Construction
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• v.19 no.1
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• pp.15-27
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• 2007

Over the past decade, labor costs have increased relative to the cost of material hardware according to analysts in the construction industry. Therefore, the minimum weight design, which has been widely adopted in the literature for the optimal design of steel structures, is no longer the most economical construction approach. Presently, although connection- related costs is crucial in determining the most cost-effective steel structures, most studies on this subject focused on minimum-weight design or engaged in higher analysis. Therefore, in this study, we proposed a fabrication scheme for the most cost-effective moment-resisting steel frame structures that resist lateral loads without compromising overall stability. The proposed approach considers the cost of steel products, fabrication, and connections within the design process. The optimal design considered construction realities, with the optimal trade-off between the number of moment connections and total cost was achieved by reducing the number of moment connections and rearranging them using the combination of analysis that includes shear, displacement and interaction value based on the LRFD code and optimization scheme based on genetic algorithms. In this study, we have shown the applicability and efficiency in the examples that considered actual loading conditions.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.4
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• pp.204-211
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• 2011

A dynamic analysis procedure is developed to provide a better estimation of the dynamic responses of bridge during the passage of high speed railway vehicles. Particularly, a three dimensional numerical model including the structural interaction between high speed vehicles, bridges and railway endures to analyse accurately and evaluate with in-depth parametric studies for dynamic responses of various bridge span lengths running KTX railway locomotive up to increasing maximum speed(450km/h). Three dimensional frame element is used to model the simply supported pre-stressed concrete (PSC) box bridges for four span lengths(40~25m). Track irregularity employed as a stationary random process from the given spectral density functions and irregularities of both sides of the track are assumed to have high correlation. The high-speed railway vehicle (KTX) is used as 38-degree of freedom system. Three displacements (Vertical, lateral, and longitudinal) as well as three rotational components (Pitching, rolling, and yawing) are considered in the 38-degree of freedom model. The dynamic amplification factors are evaluated by the developed procedure under various traveling conditions, such as track irregularity camber, train speed and ballast. The dynamic analysis such as Newmark-${\beta}$ and Runge-Kutta methods which are able to analyse considering the dynamic impact factors are compared and contrasted.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.1
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• pp.45-57
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• 2015

Soil moisture is critical for understanding the spatial-temporal variability of hydrologic processes. The distributions of soil moisture have been explored along transect line in hillslope hydrology. In this study, we measured several soil moistures along transect lines during ten-month period at a hillslope located the Cheong-mi catchment. The soil moisture properties were expressed by simple statistical methods (average, standard deviation, and recession slope) and analyzed in terms of soil depths and transects from the seasonal context. Supplementary studies were also performed about the effect of location, topography and soil texture to the soil moisture responses. The spatial distributions of average soil moisture at deep soil layer were distinguished from those at near surface due to the possibility of expected factors such as subsurface lateral flow from upslope, preferential flow and existence of bedrock. The soil moistures in combined line affected from significant contribution of upper transect line were relatively higher(wetter), low variability compared to those in other transect lines and seemed to be under stabilization process. There are confirmed heterogeneity of soil moisture variation related with preferential flow and significant influence of soil texture for soil moisture properties in upslope.

• Journal of The Korean Association For Science Education
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• v.24 no.5
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• pp.805-813
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• 2004

Our educational system clearly places much greater value on left hemisphere learning. Students who process information in other ways are at a serious disadvantage and may not be learning efficiently. Since mind mapping emphasizing visual and spatial language, it helps students to use the whole brain and promotes more effective comprehension. The purpose of this research was to determine the effects of the instruction using mind map on the science achievement of students. A pretest-posttest control group design was employed. Subjects were 153 male and female, first grade students in a middle school. A control group of 83 was instructed with a traditional teaching method, and an experimental group of 70 was instructed by using a mind mapping strategy. Two groups were treated for 50 hours during 17 weeks. Tolerance's 'Style Of Learning And Thinking(SOLAT)' was used to assess students' lateralization preferences. A 30-item multiple choice posttest was used to assess students' achievement. To analyze the data, we used an analysis of covariance(ANCOVA) and i-tests. It was found that 21.6% of students was left brain dominant, 31.4%, right brain dominant and 47.1 % was integrated style. There was no gender difference in hemispheric dominance. Significant differences existed between the test scores when they were taught by using a mind map. Mind mapping turned out to be a valuable learning technique for the right brain students, helping them to achieve the same level of subject mastery as left brain students. There was a significant difference between males and females in relation to mind map application. Female scored significantly higher than males.

• Korean Journal of Materials Research
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• v.8 no.6
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• pp.493-498
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• 1998

CdTe films were deposited by close spaced sublimation with various substrate temperatures, cell areas, and thicknesses of CdTe and ITO layers and their effects on the CdS/CdTe solar cells were investigated. The resistivity of CdTe layers employed in this study was 3$\times$ $10^{4}$$\Omega$cm For constant substrate temperature the optimum substrate ternperature for CdTe deposition was $600^{\circ}C$. To obtain larger grain size and more compact microstructure, CdTe film was initially deposited at 62$0^{\circ}C$, and then deposited at 54$0^{\circ}C$. The CdTe film was annealed at 62$0^{\circ}C$ and $600^{\circ}C$ sequentially to maintain the CdTe film quality. The photovoitaic cell efficiency improved by the "two-wave" process. For constant substrate temperature, the optimum thickness for CdTe was 5-6$\mu m$. Above 6$\mu m$ CdTe thickness, the bulk resistance of CdTe film degraded the cell performance. As the cell area increased the $V_{oc}$ remained almost constant, while $J_{sc}$ and FF strongly decreased because of the increase of lateral resistance of the ITO layer. The optimum thickness of the ITa layer in this study was 300~450nm. In this experiment we obtained the efficiency of 9.4% in the O.5cm' cells. The series resistance of the cell should be further reduced to increase the fill factor and improve the efficiency.

• Journal of Acupuncture Research
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• v.17 no.3
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• pp.125-139
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• 2000

Study of the fourteen meridians that include name of P'ung(風) point. The results were summarized as follows. 1. Pyongp'ung(秉風) is located middle of the supraspinatous fossa(Small intestine Meridian, 手太陽小腸經). we can cute the local area disease and also use to cure the pathway of the Arm greater yang small intestine which is attacked by P'ung(風) disease. 2. Yep'ung(翳風) is located behind the lobule of the auricle, in the depression between the mastoid process and the mandible(Triple Energizer Meridian, 手少陽三焦經). we can cure the local area disease especially hyper yang disease and also use to cure the pathway of the Arm lesser yang triple energizer which is attacked by P'ung(風) and Yo'l(熱) disease. 3. P'ungmun(風門) is located 1.5 chon beside the lower end of the spine of the second thoracic vertebra(Bladder Meridian, 足太陽膀胱經). we can cure the local area disease and also use to cure the pathway of the Leg greater yang bladder which is attacked by P'ung(風) disease. 4. P'ungbu(風府) is located 1 chon above the middle of natural line of the hair at the back of the head, in the depression below the occiptal protuberance(Governor meridian, 督脈). It connects (Liver meridian, 足厥陰肝經) and Yin Link Vessel(陽維脈). we can cure the rigidity and pain in head and nape which is related Yin Link Vessel(陽維脈). 5. P'ungshi(風市) is located on the lateral part of the thigh, 7 hon above the patella(From the greater trochanter to the knee joint is 19 chon, Gallbladder Meridian (足少陽膽經). we can cure the local area disease(leg, knee, etc). 6. P'ungji(風池) is located Below the occipital bone, in the depression on the outer part of the trapezius muscle(Gallbladder Meridian, 足少陽膽經) on a level with P'ungbu(風府) (Governor vessel, 督脈). we can cure the local area disease and also use to cure the pathway of the Leg lesser yang gall bladder which is attacked by P'ung(風) disease.