• 한국초등수학교육학회지
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• 제21권1호
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• pp.215-241
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• 2017

본 연구에서는 비와 비율을 지도에 대한 교사의 이해 정도를 알아보기 위하여 비와 비율 지도에 대한 교사의 교수학적 내용 지식(PCK)을 질문지와 면담을 통해 분석하였다. 연구 결과, PCK의 내용 측면에 있어서 교사는 비와 비율의 개념을 정확하게 이해하고 실생활 맥락과 연계해서 비와 비율을 지도할 필요가 있으며, PCK의 교수 방법 및 평가에 대한 지식의 관점에서 비와 비율에 대한 교수 목표를 강화하고 교수 방법에 있어서도 활동 중심으로 바뀔 수 있도록 교사들의 PCK를 강화할 필요가 있다. 그리고 학생 이해 지식의 관점에서 교사의 PCK는 교사의 설명 이외에 오류 지도 방법을 다양화하고 정의적 측면을 수업에 연계할 수 있도록 해야 한다. 마지막으로 수업 상황에 대한 지식의 관점에서 교사는 주체적 관점에서 교과서 활동을 재구성하고, 활동의 특성에 맞게 수업 집단을 다양화 할 필요가 있다. 본 연구 결과는 설문과 면담을 통한 비와 비율에 대한 교사의 PCK가 실제 수업과 어떠한 연관성을 갖고 있는지에 대한 추후 연구를 제안한다.

• Imaging Science in Dentistry
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• 제44권3호
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• pp.193-198
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• 2014

Purpose: The present study was aimed to investigate the variation of soft palate morphology in different age and gender groups. The correlations of radiographic velar length (VL), velar width (VW), pharyngeal depth (PD), and Need's ratio with soft palate variants were also studied in the North Indian subpopulation. Materials and Methods: The study sample consisted of 300 subjects aged between 15 and 45 (mean: 31.32) years. The velar morphology on lateral cephalograms was examined and grouped into six types. The results obtained were subjected to a statistical analysis to find the correlation between variants of the soft palate with gender and different age groups. Results: The most frequent type of soft palate was leaf shaped (48.7%), and the least common was crook shaped (3.0%) among both the genders and various age groups, showing a significant correlation. The mean VL, VW, and PD values were significantly higher in males and significantly correlated with the types of soft palate. A significant correlation was observed between the mean VL, VW, PD, and Need's ratio with various age groups, showing an inconsistent pattern with an increase in age. The types of soft palate, gender, and Need's ratio were also significantly correlated, with an overall higher mean value of the Need's ratio among female subjects and the S-shaped soft palate. Conclusion: The knowledge of a varied spectrum of velar morphology and the variants of the soft palate help in a better understanding of the velopharyngeal closure and craniofacial anomalies.

• Journal of the Korean Data and Information Science Society
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• 제22권1호
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• pp.107-113
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• 2011

We present methods for studying the log-density ratio, which allow us to select which predictors are needed, and how they should be included in the logistic regression model. Under multivariate normal distributional assumptions, we investigate the form of the log-density ratio as a function of many predictors. The linear, quadratic and crossproduct terms are required in general. If two covariance matrices are equal, then the crossproduct and quadratic terms are not needed. If the variables are uncorrelated, we do not need the crossproduct terms, but we still need the linear and quadratic terms.

• 근관절건강학회지
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• 제4권1호
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• pp.61-73
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• 1997

This study deals with needs assessment for home exercise of 233 arthritis patients, who visited 2 university hospitals in Seoul from May 27. to June. 15. 1996. Data was collected through the interview with them. As a result, we came to the following points. 1. Seventy five percent of all interviewees expressed strong will to home exercise, if they know how to do. 2. With no partners for life. the needs for home exercise were higher than those who have (P=0.016). 3. Christians(87.1%) and Catholics(86.4%) had more the need for home exercise those who have Buddhist(70.9%) and atheist (60%) (P=0.002). 4. In the direct ratio to level of education. the need for home exercise was high (P=0.027). 5. In the inverse ratio to age. the need for home exercise was high(t=6.20. P=0.0000). 6. Patients with arthritis for relatively short period of time had more than those who had long period of the disease need for home exercise(t=3.36, P=0.0013). 7. Those who have long distance from hospital had more needs for home exercise than those who line in short distance (t=3.15 P=0.002) 8. When average cost of hospital visit for each time is much. then need for home exercise was high(t=4.20, P=0.0001).

• 한국초등수학교육학회지
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• 제20권1호
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• pp.1-15
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• 2016

본 논문에서는 우리나라 초등학교 수학 교과서 및 익힘책에서 취급하는 내포량과 관련하여 다음 세 가지 쟁점에 관해 논의하고 있다. (1) 내포량, 단위량당의 크기, 비율 사이에 어떠한 관계가 있는가? (2) 어떤 율을 어떻게 취급하고 있는가? (3) 어떤 도를 어떻게 취급하고 있는가? 이에 대한 논의 결과를 바탕으로, 내포량 취급의 발전 방향을 모색하기 위한 다음 세 가지 시사점을 결론으로 제시한다. 첫째로, 내포량을 취급하는 일련의 과정을 체계화할 필요가 있다. 예를 들어 비율을 취급하기 전에 속력, 속도라는 표현을 사용하는 것 등은 재고할 필요가 있다. 둘째로, 특정한 이름이 붙는 내포량의 정의를 재고할 필요가 있다. 예를 들어 속력의 정의에서 평균 거리, 인구밀도의 정의에서 평균 인구를 사용하는 것은 재고할 필요가 있다. 셋째로, 초등학교 수학과에서 취급하는 율의 종류를 한정하는 것을 생각해 볼 필요가 있다. 예를 들어 일상생활에서 사용하는 율에 한정하고, 전문적인 율의 취급은 재고할 필요가 있다. 또, 타율에 %를 붙여 나타내는 것은 재고할 필요가 있다.

• Bulletin of the Korean Chemical Society
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• 제20권7호
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• pp.815-818
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• 1999

The method of calculating the excess Helmholtz free energy from the averaged effective acceptance ratio for the Lennard-Jones fluid and the inverse twelve fluid has been slightly modified and applied to the two-center-Lennard-Jones liquid. The excess Helmholtz free energy is calculated directly from the average of the modified effective acceptance ratio through a single Metropolis Monte Carlo simulation. Therefore this method does not need any reference system. The results of the present method were satisfactory compared with those of the perturbation theories and the overlap ratio method.

• 응용통계연구
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• 제26권1호
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• pp.141-149
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• 2013

로지스틱회귀모형에서 두 설명변수의 조건부 분포가 모두 이변량 정규분포라고 할 수 있다면 설명변수들의 함수로 표현되는 로그-밀도비를 통해 모형에 포함시켜야하는 항을 알 수 있다. 두개의 이변량 정규분포에서 분산-공분산행렬이 같은 경우에는 이차항과 교차항 없이 일차항만으로 충분하다. 상관계수가 모두 0이면 교차항은 설명변수의 분산과 관계없이 필요하지 않다. 또한 로지스틱회귀모형에서 로그-밀도비를 통해 이차항과 교차항이 필요하지 않게 되는 다른 조건들도 알아본다.

• 소음진동
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• 제10권2호
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• pp.325-330
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• 2000

A dynamic absorber is used to protect the primary vibration system under the steady-state harmonic disturbance. In a number of cases it appears expedient to install several absorbers of smaller masses instead of one. This may be due to the need of distribute the absorber's response along the construction, restrictions on the absorber's installation. So, we studied characteristics of the primary vibration system for the optimal natural frequency ratio and the optimal damping ratio of serial multi-dynamic absorber. Also we obtained the optimum values of the serial multi-dynamic absorber parameters using computer simulation for the damped primary vibration system. In designing multi-dynamic absorber, we presented for the optimal natural frequency and the optimal damping ratio of multi-dynamic absorbers.

• 통상정보연구
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• 제9권3호
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• pp.151-160
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• 2007

The purpose of this study is to estimate the risk premium hedge ratio in foreign exchange risk of the foreign exchange rate insurance. The applicants of exchange rate insurance and Korea Export Insurance Corporation will be facing the risk in change of currency and guaranteed currency’s swap point upon contract being made. Also upon making decision of hedging exchange rate insurance, the company will need to be aware of the risk causing due to change in swap point.

• 산업기술연구
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• 제17권
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• pp.313-322
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• 1997

As the weight of trucks increases, the need for concrete pavement also increases. Therefore, the addition of fly-ash may improve the properties of pavement concrete as well as recycle fly-ash. A full factorial experiment was performed using the primary variables, such as water-cement ratio, fly-ash substitution ratio, and maximum size of coarse aggregate, as a preliminary study for optimum mixture design for pavement concrete. The results of preliminary study indicates that the addition of fly-ash is the most important factor determining concrete strength, followed by the maximum size of coarse aggregate and water-cement ratio. It, also, shows the relative importance of fly-ash substitution ratio, compared to the water-cement ratio, and the interaction effects between the primary variables. Optimum mixture designs for pavement concrete incorporating fly-ash, that satisfied the target responses, were proposed in terms of fly-ash substitution ratio, water cement ratio and maximum size of coarse aggregate.