• The Journal of the Korean dental association
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• v.34 no.3 s.322
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• pp.160-162
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• 1996

같은 급의 부정교합이라도 악골의 수직 수평관계, 악골과 치아의 크기에 따라서 여러 유형으로 분류된다. 여러 유형에 따라 치료방법에도 일률적일 수 없고 다양하게 된다. 진단과 치료계획 수립 시에 종종 어려움을 겪게 되는 경우가 있다. 진단의 어려움을 겪는 경우는 발치할 것인지 여부, 어떤 치아를 발치할 것인지, 악궁과 치아크기의 부조화를 어떻게 해소시킬 것인지 들의 결정을 내릴 때이다. 이런 경우 정확한 두부방사선분석 석고모형 분석, 성장과 발육분석에 의하여 판단하며 무엇보다 술자의 능력에 맞게 최선의 방법을 선택하는 것이 중요하다. 부정교합의 유형에 따라 다양한 발치 등 방법을 보고하고자 한다.

• Korean Journal of Agricultural Science
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• v.10 no.2
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• pp.277-291
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• 1983

In order to investigate the shear characteristics of earth structure after construction. Four sample soils with different gradation were selected and compacted under the optimum moisture content and the maximum dry density. And the direct shear test and the triaxial compression test were performed with those sample soils under various pre-compression loads. The results were summarized as follows; 1. With the increase of the percent passing of No. 200 sieve, the cohesion of soil increased regularly and the internal friction angle of soil decreased with slow ratio. 2. The pre-compression increased the shear strength of compacted cohesive soil. The increase of cohesion was very apparent but the internal friction angle didn't show such regular tendency. 3. With the increase of pre-compression load, the slope of stress-strain curve showed steep at the early stage of horizontal strain. The vertical strain was small at the compression stage and big at the expansion stage. 4. When the vertical stress of shear test with increase in the horizontal strain was small, stress ratio(shear stress vs. vertical stress) of sample showed the largest value and the slope of stress ratio curve showed also steep. 5. When the sample was had the same condition, the cohesion of soil showed bigger value in the triaxial compression test and the internal friction angle of soil showed bigger value in the direct shear test.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1061-1064
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• 2010

뒷채움재료의 선정기준으로 구조물과 연이은 토공부 사이의 부등침하를 최소화하기 위해 맞물림(Interlocking)효과 및 다짐성이 우수하고 배수가 원활히 될 수 있는 입상재료인 선택층 재료를 사용하는 것으로 규정 및 설계하고 있다. 일률적으로 정해진 현재의 뒤채움재료 선정기준은 건설초기에 손쉽게 구할 수 있었던 선택층 재료인 SB-1의 공급이 어려워져 적절하게 현장여건을 고려하기 곤란하다. 공학적 측면에서 지나치게 안전측으로 선택 및 설계되는 경우가 있어 공사비의 상승 등 시공성과 경제성 측면에서 많은 문제점을 가지고 있다. 본 연구에서는 실내 모형토조를 이용하여 뒤채움 완료 후 뒤채움부 상단에서 교통하중에 의한 장기동적토압을 모사해 뒤채움부의 장기 침하량과 수직, 수평토압을 측정 비교해 교대 뒤채움부 재질 변경을 위한 기초자료로 활용하고자 한다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.919-924
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• 2005

Fretting-wear caused by turbulence excitation for KSNP(Korea standard nuclear power plant) steam generator is investigated numerically. Secondary sides density and normal velocity are obtained by the thermal-hydraulic data of the steam generator. Because nonlinear finite element analysis is complex and time consuming, work rate is estimated by using linear analysis for simple straight 2-span tube. Wear volume and depth by using work rate calculation are estimated. Span length, secondary side fluid density and normal velocity are adopted to study the effects on the fretting-wear by turbulence excitation. When secondary sides density and normal velocity is increased, It turns out that secondary side density and normal gap velocity are very important paramater for fretting-wear phenomena of the steam generator.

• Journal of Digital Convergence
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• v.12 no.11
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• pp.451-459
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• 2014

This study was to performed to get the reference data of the kinetic parameters for normal subjects according to the arm swing type. Forty-five normal subjects($22.62{\pm}2.69years$) pariticpated in this study and preformed 4 sequence according to the arm swing type as follows; first procedure-normal arm swing, second procedure-one arm swing, thrid procedure-no arm swing, fourth procedure-fitness arm swing. There were significant differences according to the arm swing type in the kinetic parameters such as walking speed, hip power, ground reaction force of vertical in terminal stance phase(p<.05). These finding can be utilized (a) as a reference for kinetic data of gait analysis in normal subjects, and (b) as an aide in evaluating and treating patients who have problems relating to gait.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.9 s.114
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• pp.904-911
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• 2006

A modified energy method for the fretting wear of the steam generator tube is proposed to calculate the wear-out depth between the nuclear steam generator tube and its support. Estimation of fretting-wear damage typically requires a non-linear dynamic analysis with the information of the gap velocity and the flow density around the tube. This analysis is very complex and time consuming. The basic concept of the energy method is that the volume wear rate due to the fretting-wear phenomena Is related to work rate which is time rate of the product of normal contact force and sliding distance. The wearing motion is due to dynamic interaction between vibrating tube and its support structure, such as tube support plate and anti-vibration bar. It can be assumed that the absorbed work rate would come from turbulent flow energy around the vibrating tube. This study also numerically obtains the wear-out depth with various wear topologies. A new dissection method is applied to the multi-span tubes to represent the vibrational mode. It turns out that both the secondary side density and the normal gap velocity are important parameters for the fretting-wear phenomena of the steam generator tube.

• Journal of the Korea Concrete Institute
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• v.11 no.3
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• pp.81-88
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• 1999

In order to properly evaluate the shear strength of reinforced concrete circular columns due to the transverse shear reinforcement, the average of fractions of forces generated along the circular transverse hoops across the shear failure plane in the loading direction is calculated. For this, the center-to-center diameter of circular transverse hoops. spacing and the crack angle measured to the column longitudinal axis are considered. Using these variables, an equation representing the effective section area of circular transverse shear steel is proposed. The study result shows that the constant parameter. used for the calculation of the effective section area of circular hoops over the last 10 years, should not universally be applied any more. The use of the constant parameter may not seriously do harm to the evaluation of shear strength for circular columns with non-seismically designed transverse hoop reinforcement, since it gives slightly conservative results. However. for well-confined circular columns with close spacing or circular steel jacketing. it gives about 20% overestimation of the shear capacity contributed by the transverse hoop steel.

• Clinical and Experimental Pediatrics
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• v.51 no.11
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• pp.1165-1171
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• 2008

Purpose : This study aimed to identify the true extent of non-responsiveness in full-term infants born from HBsAg-negative or HBsAg-positive mothers and vaccinated against hepatitis B virus (HBV) at 0, 1, and 6 months of age and to evaluate the effect of revaccination among non-responders. Methods : The study included 716 full-term infants born in 2004-2007. Of 716, 662 infants (A group) were born to HBsAg-negative mothers and 54 infants (B group: 50, except HBsAg-positive infants) were born to HBsAg-positive mothers. All infants were administered DNA recombinant vaccines at 0, 1, and 6 months of age. B group infants received hepatitis B immunoglobulin at birth. Anti-HBs titers were tested at 7-12 and 9-15 months in A and B groups, respectively. Three revaccination doses were administered to non-responders whose anti-HBs titers were under 10 mIU/ml; revaccinated infants were retested at 1-3 months after last vaccination. The association between HBeAg seropositivity of mother and the failure of HBV immunoprophylaxis was evaluated. Results : The seroconversion rates after primary hepatitis B vaccination were higher in A group (94.1%) than in B group (78%, P<0.001). The seroconversion rates were high in revaccinated infants (A group non-responders: 96.9%, B group non-responders: 87.5%). The failure of HBV immunoprophylaxis was significantly associated with maternal HBeAg seropositivity (P<0.001). Conclusion : The seroconversion rates after primary hepatitis B vaccination were low in B group infants. Revaccination of non-responders in B group was very effective. Therefore, anti-HBs testing and revaccination of B group is very important. Revaccination of non-responders in A group was also very effective. Thus, testing the immune status of infants born to HBsAg-negative mothers even after primary hepatitis B vaccination should be considered. However, to realize this, further studies on the cost-effectiveness of anti-HBs testing in healthy full-term infants are necessary.

• Land and Housing Review
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• v.5 no.1
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• pp.25-34
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• 2014

This study starts from the fact that we need residential complex for the purpose of public interests, rather than for profits, and find a new perspective on the concept of public-oriented residential complex in the cities that had slow growth. In this study, we 1) propose a new concept of the residential complex that can vitalize regional communities and maintain the interest of the public : 'functional-mix', 'social-mix', 'spatial-mix', 2) produce a model simulation based on the development principles including development direction, types of development, and design guidelines, ; six development principles(goal, concept, development type, spatial structure, space element, spatial hierarchy), diversity of housing types, facilities that can vitalize and contribute the regional communities 3) propose practical methods that can realize and promote the proposed concept and model simulation. ; need to amend the housing construction Law.

• Korean Journal of Agricultural Science
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• v.5 no.1
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• pp.15-28
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• 1978

It has been known that the shear strength of soil is an important design parameter for the foundation of structures, the retaining walls, the slope failures and so forth. In this study, the shear test was performed by using the direct shear apparatus under various degree of the moisture content and the density of the sample soils. The results of the study were summarized as follows; 1. The shear strength of soil increased with increase in the dry density of soil, and at the same level of density of the sample the shear strength of soil showed large values on a good grading of the sample. 2. The cohesion of the soil varied directly with the dry density of it, however the internal friction angle of soil was not affected by the dry density of tile sample. 3. The shear strength of sample varied inversly with the moisture content of it, and this phenomenon was apparent on a good grad ing of sample. 4. The cohesion of soil showed maximum value when the moisture content of the soil reached optimum level and the internal friction angle decreased with increase in the moisture content of it. These phenomena were very obvious on a good grading sample, SDC-1. 5. The cohesion of the soil decreased with increase in void ratio of the sample, but the internal friction angle of the sample didn't show such tendency.