• 한국교육학연구
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• 제24권3호
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• pp.167-189
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• 2018

본 연구는 경기교육종단연구 중1 코호트의 1, 2차년도 데이터와 초4 코호트의 4, 5차년도 데이터를 사용하여 혁신학교 일반화의 일환으로 실시된 혁신학교 확대 운영 정책이 경기도 중학교의 학교효과성 변화에 미치는 영향을 분석하였다. 혁신학교 일반화 이전과 이후에 중학교 2학년의 학업성취도, 학교만족도, 자발적 주도적 창의성, 공동체의식에 대한 혁신학교의 학교효과성을 비교하기 위해 반복 횡단면 자료를 이용한 이중차분법 모형을 적용하였다. 분석 결과 혁신학교는 혁신학교 일반화 이전에는 일반학교와 크게 다르지 않은 학교효과성을 나타내었다. 그러나 혁신학교 일반화 이후에는 학업성취 및 학교만족도에 대하여 일반학교에 비해 학교효과성이 유의하게 향상된 것으로 나타났다. 이러한 변화는 기존 혁신학교들이 연차가 축적됨에 따라 학업성취에 대한 학교효과성이 향상되고 높은 수준의 학교만족도를 유지하는 한편, 혁신학교 양적 확대에 따라 학업성취에 대한 효과성이 뛰어난 일반학교들이 추가로 혁신학교로 전환되면서 학교만족도에 대한 효과성이 향상된 것에 기인하는 것으로 밝혀졌다. 반면 자발적 주도적 창의성이나 공동체의식에 대한 학교효과성은 양적 확대 이전과 이후에 모두 혁신학교와 일반학교 간 차이가 유의하지 않은 것으로 판명되었다. 이상의 분석 결과를 바탕으로 혁신학교 일반화 정책을 평가하고, 정책 개선 방안에 대해 논의하였다.

• 한국전산구조공학회논문집
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• 제20권3호
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• pp.321-327
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• 2007

본 연구는 탄성균열문제를 신속하고 정확하게 해석할 수 있는 새로운 개념의 그리드(grid) 없는 유한차분법을 제시한다. 이동최소제곱법을 이용한 Taylor 전개식 구성을 통해 직접적인 미분계산 없이 근사함수와 그 미분을 손쉽게 계산한다. 그리드로 인한 절점 간의 종속성이 없어 해석영역 내의 불연속면 모델링이 용이하여 차분식 구성시 균열로 인한 불연속 효과를 고려하는 과정도 자연스럽다. 유한차분법에 근간을 두고 있어 지배 미분방정식을 직접 이산화하기 때문에 수치적분이 필요한 수치기법에 비해 계산속도도 빠르다. 모드 I과 모드 II 균열문제 해석을 통해 본 해석기법이 정확하고 효율적으로 응력확대계수를 계산할 수 있음을 보였다.

• 한국환경과학회지
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• 제22권10호
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• pp.1345-1351
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• 2013

Leaf characteristics of two representative deciduous-tree species in Korean peninsula were compared to assess directional ridge effect on leaf traits of both species. Leaf mass per unit area (LMA) of Rhododendron schilippenbachii in south-facing ridge slope was significantly higher than that in north-facing ridge slope, while Quercus mongolica did not change LMA. Leaf mass of Q. mongolica was increased depending on leaf size irrespective of slope. However, leaf mass of R. schilippenbachii changed differently in responding to expansion of leaf area between both slopes resulting from retardation of leaf expansion in south-facing slope. R. schilippenbachii showed higher leaf nitrogen concentration per unit area (LNCA) in south-facing slope than that in north-facing slope, while Q. mongolica indicated no difference in LNCA between southand north-facing slopes. However, both species revealed no significant difference in leaf nitrogen concentration per unit mass (LNCM) between south- and north-facing slopes. LNCA of Q. mongolica was about two times higher than that of R. schilippenbachii. These results indicate that there is a difference in leaf characteristics including leaf thickness and nitrogen allocation between Q. mongolica and R. schilippenbachii, suggesting the difference of plasticity.

• 한국전기전자재료학회논문지
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• 제21권10호
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• pp.954-960
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• 2008

The effects of elastic modulus coefficient and linear expansion coefficient of overhead distribution power line(ACSR $58 mm^2$) on sag behavior in distribution line have been investigated to clarify the difference between specification and experimental level. The elastic modulus coefficients of Al wire and steel wire were $5,182.6 kgf/mm^2,\;18,348.8 kgf/mm^2$, respectively Therefore, the computational composition elastic modulus coefficient of the power line was $7,063.5 kgf/mm^2$, while that of experimentally measured was $7681.1 kgf/mm^2$. As a result, we found that elastic modulus coefficient which was experimentally measured was higher than that of computational by 8.7 %. However, when planner designs the sag of disoibution line, the elastic modulus coefficient of power line $8,400 kgf/mm^2$ should be generally adopted. These two different using values lead to the sag difference of 0.62 m. The other results will be discussed.

• 대한통합의학회지
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• 제4권1호
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• pp.73-83
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• 2016

PURPOSE : The purpose of this study to suggest the exercise programs for improving the function and structure by applying the Masan university scoliosis program exercise method and electrical therapy method to the scoliosis patient. METHODS : The subjects were 18 patients who were diagnosed with scoliosis. They were randomly assigned either to a Masan university scoliosis program exercise group (n=11) that received Masan university scoliosis program exercise program or to a electrical therapy group (n=7). Flexibility, static balance, dynamic balance, and spinal angles were measured by using one leg standing with closed eyes, functional reach test, and Cobb's angle, respectively. The chest expansion were calculated using differences of chest circumference between maximum inspiration and maximum expiration. RESULT : Masan university scoliosis program group before and after the intervention there was a difference in the static balance, spine angle(p<.05). Masan university scoliosis program group before and after the intervention there was a difference in the flexibility, static balance, spine angle, chest expansion (p<.05). CONCLUSION : These results revealed that Masan university scoliosis program exercise program improved flexibility, static standing balance, spine angle, used as scoliosis management and intervention. Therefore, it is expected to be used as a method for the treatment and prevention in the process of rehabilitation of patients with scoliosis.

• Journal of applied mathematics & informatics
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• 제35권3_4호
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• pp.277-302
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• 2017

In this paper, we have proposed a numerical method for Singularly Perturbed Boundary Value Problems (SPBVPs) of reaction-diffusion type of third order Ordinary Differential Equations (ODEs). The SPBVP is reduced into a weakly coupled system of one first order and one second order ODEs, one without the parameter and the other with the parameter ${\varepsilon}$ multiplying the highest derivative subject to suitable initial and boundary conditions, respectively. The numerical method combines boundary value technique, asymptotic expansion approximation, shooting method and finite difference scheme. The weakly coupled system is decoupled by replacing one of the unknowns by its zero-order asymptotic expansion. Finally the present numerical method is applied to the decoupled system. In order to get a numerical solution for the derivative of the solution, the domain is divided into three regions namely two inner regions and one outer region. The Shooting method is applied to two inner regions whereas for the outer region, standard finite difference (FD) scheme is applied. Necessary error estimates are derived for the method. Computational efficiency and accuracy are verified through numerical examples. The method is easy to implement and suitable for parallel computing. The main advantage of this method is that due to decoupling the system, the computation time is very much reduced.

• 한국분말재료학회지
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• 제17권1호
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• pp.1-6
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• 2010

In this study, a convergent heat treatment was performed in certain temperature regions in order to control the microstructures of Nd-rich phases and to reduce thermal stress on grain boundaries which could be caused during expansion and shrinkage of Nd-rich and $Nd_2Fe_{14}B$ phases. The difference of thermal expansion coefficient between $Nd_2Fe_{14}B$ and Nd-rich phases is the mechanism for convergent heat treatment. The Nd-rich phases which were located in junctions could penetrate into the grain boundaries between $Nd_2Fe_{14}B$ phases due to the difference of thermal expansion coefficient. Through the convergent heat treatment, the microcracks that were observed in cyclic heat treatment were not observed and coercivity was increased to 34.05 kOe at 8 cycles.

• 패션비즈니스
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• 제10권6호
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• pp.122-130
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• 2006

The purpose of this study is to develop the appropriate brassiere pattern for women. Total of 6 brands with same design and 75A, 80A size brassieres(total 12 brassieres) were compared and analyzed for pattern, cup size and patterns. SPSS 10.1 statistic process was used for data analysis. The outcom of this study is summarized as follows. Total length of brassiere by grade were performed smaller than the standard difference 5cm. For 1/2 front cover length, There were no significant differences between 75 and 80. The reason for lower line of wing is shorter than upper line of wing is because side support is cut side ways considering lower line of wing is sewn more toward front than upper line of wing. Even it is same A cup size most cup related sizes become larger according to underbust comparing with cup capacity, they range from 146.67cc to 172.83cc for same A cups. Among same A cups with difference underbust there was average of 26.16cc differences. For relations of material, sewing technology and expansion rate, all 6 brands had zigzag type sewing for upper line tape. For every 0.3cm height, there were $17{\sim}21$ stitches. When urethane mixture is similar expansion rate is higher while number of 1 inch zigzag are high. For elasticity, zigzag stitch expand side ways for more expansion.

• Communications for Statistical Applications and Methods
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• 제23권1호
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• pp.21-32
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• 2016

We study asymptotic expansion formulae for numerical computation of Greeks (i.e. sensitivity) in finance. Our approach is based on the integration-by-parts formula of the Malliavin calculus. We propose asymptotic expansion of Greeks for a stochastic volatility model using the Greeks formula of the Black-Scholes model. A singular perturbation method is applied to derive asymptotic Greeks formulae. We also provide numerical simulation of our method and compare it to the Monte Carlo finite difference approach.

• 대한전자공학회논문지TC
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• 제47권11호
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• pp.14-18
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• 2010

M-ary와 PN 확산의 조합이 존재하는 CDMA 시스템에서 성능분석 방법을 제안하였다. M-ary와 PN 확산에 의한 전체 대역폭 확장이 같더라도 두 블럭의 대역폭 확장의 조합에 따라 시스템 성능이 달라진다. 따라서 M-ary와 PN 확산이 이루는 CDMA 시스템 전체 대역폭 확장이 아니라, 각각의 대역폭 확장을 사용하여 시스템 성능을 분석하였다. 그리고 SINR이 높을수록 M-ary에 의한 대역폭 확장이 PN 확산에 의한 대역폭 확장보다 비트오율을 더 많이 감소시키는 것을 볼 수 있었다. 제안한 성능분석 방법이 M-ary에 의한 성능개선의 효과를 반영했기 때문에 전체 대역폭 확장만을 사용한 방법보다 더 정확한 성능분석을 할 수 있었다.