• Journal for History of Mathematics
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• v.18 no.1
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• pp.33-48
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• 2005

The Rule of False Position is known as an arithmetical solution of algebraical equations. On the other hand, the Excess-Deficit Rule is an algorithm for calculating about excessive or deficient quantitative relations, which is found in the ancient eastern mathematical books, including the nine chapters on the mathematical arts. It is usually said that the origin of the Rule of False Position is the Excess-Deficit Rule in ancient Chinese mathematics. In relation to these facts, we pose two questions: - As many authors explain, the excess-deficit rule is a solution of simultaneous linear equations？ - Which relation is there between the two rules explicitly？ To answer these Questions, we consider the Rule of Single/Double False Position and research the Excess-Deficit Rule in some ancient mathematical books of Chosun Dynasty that was heavily affected by Chinese mathematics. And we pursue their historical traces in Egypt, Arab and Europe. As a result, we can make sure of the status of the Excess-Deficit Rule differing from the Rectangular Arrays(the solution of simultaneous linear equations) and identify the relation of the two rules: the application of the Excess-Deficit Rule including supposition in ancient Chinese mathematics corresponds to the Rule of Double False Position in western mathematics. In addition, we try to appreciate didactical value of the Rule of False Position which is apt to be considered as a historical by-product.

• Annual Conference on Human and Language Technology
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• 1996.10a
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• pp.123-127
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• 1996

영어와 한국어의 통사구조의 차이로 인하여, 이중언어자와 비이중언어자인 한국 대학생의 영어 문장 유형에 따른 통사 처리에 있어 차이가 있을 것이다. 네가지 영어 문장 유형, 수동태, 관계사절, 물주구문, 가정법 구문 등으로 문장 완성 과제를 실험하여 이중언어자와 비이중언어자의 문장완성 시간과 오류율을 측정하였다. 실험 결과 비이중언어자인 한국 대학생은 다른 문장 유형에 비하여 물주구문에서의 통사처리 수행에 있어 이중언어자와 유의한 차이를 보였다. 이로부터 이중언어자와 한국 대학생의 영어 문장의 통사 정보처리의 자동화 및 어순효과 정보와 생물 주어(word animacy)구문 단서, 즉 대부분의 주어는 살아있는 사물의 명사로 이루어져 있다는 단서(Gass, l987)의 사용에 대하여 논의하였다.

• 한국사회정책
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• v.23 no.1
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• pp.25-59
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• 2016

This paper analyses the policy effect of minimum housing standards, using the fact that Seoul set the minimum housing standards in 1998. Because the whole country except Seoul did not set the minimum housing standards in 1998, we could find this situation as a quasi-experiment. In order to identify the policy effect of minimum housing standards, I compare decreasing amounts in the number of households below the threshold between Seoul and comparison regions from 1995 to 2000, using Differences-in-Differences method. I draw estimate of one-to-one comparison, using Gyeonggi province as a comparison region, and OLS estimate, utilizing the whole nation except Seoul as a comparison region, respectively, and compare two estimates. The former and the latter suggest that the setting of Seoul minimum housing standard in 1998 account for decreasing the number of households under the minimum housing standard, by about 216,638 and 325,149, respectively. The latter is statistically significant at the 0.001 level and the former is in the 95% confidence level of the latter. Therefore we could conclude that the setting of minimum housing standards contributes significantly to achieve the policy objectives, a decrease in the number of households, which are below the threshold.

• Journal of the Korea Society of Computer and Information
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• v.24 no.10
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• pp.233-242
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• 2019

At present, our society is reducing the birth rate, and the school population is decreasing, but multicultural students are facing the increasing social phenomenon. We all need to make sure that bilingual teaching and learning is effective for children of multicultural families who need to live in the days of Phono Sapiens so that they can live confidently as members of our society. To this end, there is a great need for a bilingual teaching and learning method that enables children from multicultural families to be free from language and cultural prejudice and to actively communicate and interact. In this paper, we propose a customized bilingual education method that applies various teaching and learning methods according to the development cycle, school age, and Korean language ability of children of multicultural families. The proposed bilingual teaching method for children of multicultural families is a teaching and learning method that applies the Waldorf teaching principle.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.442-442
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• 2010

공정 플라즈마 장치에서 이중 주파수법을 이용하여 실시간 유전박막 두께 측정법에 대한 보상연구를 하였다. 이중 주파수법은 유전박막과 플라즈마 쉬스를 간단한 전기적인 등가회로로 모델링하여 유전박막의 두께를 측정하는 방법이다. 이중 주파수법의 문제는 측정탐침의 인가전압에 따른 유전박막의 두께 측정치가 다르다는 점이다. 플라즈마 쉬스를 선형 저항만으로 등가하였기 때문에, 쉬스의 인가전압에 상관없이 쉬스 저항의 값이 일정하다는 가정이 존재한다. 그러나 쉬스 저항은 쉬스의 인가전압에 종속적이면서 비선형적인 특성을 갖는다. 측정 탐침에 출력 전압이 인가될 때 쉬스 양단에서 인가전압에 따른 쉬스의 등가저항의 비선형성을 고려하여 측정 탐침에 증착된 유전박막의 커패시턴스성분에 대한 방정식을 Numerical analysis로 풀어 유전박막의 두께 측정값을 보상하였다. 보상된 위의 방법으로 다양한 RF파워, 압력에 따라 $Al_2O_3$박막의 두께를 실시간으로 측정하여 비교하였다. 그 결과 이 방법은 낮은 플라즈마 밀도(${\sim}10^9cm^{-3}$)에서도 인가전압에 따른 유전 박막두께측정의 오차를 줄일 수 있었다.

• Journal of Families and Better Life
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• v.13 no.3
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• pp.156-169
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• 1995

본 연구는 체계론에 근거하여 농촌가정의 의사소통효율성, 재무관리행동, 가정생활 만족간의 관계를 분석하고자 하였다. 연구 결과 체계론에 의해 제시된 개념적 틀을 지지하는 것으로 나타났으며 이를 요약하면 다음과 같다. 1) 의사소통효율성에 직접효과를 미친 변수는 경제문제 경험도와 경제적 상승감이었다. 재정관리행동에는 경제문제 경험도, 경제적 기대감, 의사소통효율성이 직접효과를 미쳤고, 경제문제경험도는 의사소통효율성을 통한 간접효과도 미치는 것으로 나타났다. 2) 경제문제경험도, 경제적 상승감, 경제적 기대감, 의사소통효율성, 재무관리행동의 변수가 산출요소인 가정생활만족에 직접적인 효과를 보였고, 이중 재무관리행동을 제외한 4개 변수 모두 재무관리행동을 통한 간접효과도 미치는 것으로 나타났다.

• Journal of Korean Society of Steel Construction
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• v.19 no.6
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• pp.737-749
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• 2007

Flexural design of double composite box girder over the interior pier for three-span continuous bridge was performed by the LRFD method. The maximum span length of the continuous bridge ranged from 80m to 120m and the relative ratio of the span length was assumed to be 1:1.25:1. The girder section was designed for the strength limit state and service limit state with additional design check for constructibility. Before the bottom concrete and compression flange showed a complete composite action, the buckling of lower compression flange was checked. The flexural stiffness and flexural resistance characteristics for the section and for the constituent members such as tension flange, compression flange, and web were analyzed for different thicknesses of the bottom concrete on top of the compression flange. The effect of the distribution ratio of steel between the top and bottom flanges was investigated by analyzing ductility behavior and stress distribution through the girder's depth for several different relative area ratios of steel between the top and bottom flanges. It was found that a total amount of 15% of steel can be saved by applying the double composite system compared with that of the conventional composite system.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.6
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• pp.896-906
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• 1997

The effect of duplicate flexible disks on the vibrational modes of a flexible rotor system is investigated by using an anlytical method based on the assumed modes method. The rotor model to be analyzed consists of duplicate disks on a flexible shaft. In modeling the system, centrifugal stiffening and disk flexibility effects are taken into account. To demonstrate the effectiveness of the method, a hard disk drive spindle system commonly used in personal computers and a simple flexible rotor system with two disks are selected as examples. In particular, the dynamic coupling between the vibrational modes of the shaft and the duplicate disks is investigated with the shaft rotational speed varied.

• Journal of Biomedical Engineering Research
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• v.16 no.2
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• pp.223-230
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• 1995

This study investigates a combined mathematical model for the quantitative estimation of regional myocardial blood flow in experimental canine coronary artery occlusion and in patients with ischemic myocardial diseases using Rb-82 dynamic myocardial positron emission tomography. The coronary thrombosis was induced using the new catheter technique by narrowing the lumen of coronary vessel gradually, which finally led to partial obstruction of coronary artery. Thirty four Rb-82 dynamic myocardial PET scans were performed sequentially for each experiment using our 5, 10 and 20 second acquisition protocol, respectively, and six to seven regions of interest were drawn on each transaxial slices, one on left ventricular chamber for input function and the others on normal and decreased perfusion myocardial segments for the flow estimation in those regions. Two compartment model and graphical analysis method have been applied to the measured sets of regional PET data, and the rate constants of influx to myocardial tissue were calculated for regional myocardial flow estimates with the two parameter fits of raw data by the Levenberg-Marquardt method. The results showed that, (I) two compartment model suggested by Kety-Schmidt, with proper modification of the measured data and volume of distribution, could be used for the simple estimation of regional myocardial blood flow, (2) the calculated regional myocardial blood flow estimates were dependent on the selection of input function, which reflected partial volume effect and left ventricular wall motion in previously used graphical analysis, and (3) mathematically fitted input and tissue time activity curves were more suitable than the direct application of the measured data in terms of convergence.

• Journal of the Society of Naval Architects of Korea
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• v.38 no.1
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• pp.43-51
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• 2001

The unsteady problems of ships in waves are analyzed by a low order panel method with Rankine source. Considering the basic flow as the uniform incoming flow(so called Kelvin flow) and also the double body flow. the solutions to satisfy the governing equation with the boundary conditions are obtained, and these two results are compared. The hydrodynamic coefficients for the modified Wigley hull and Series 60($C_B=0.7$) are computed and compared with the experimental data available and also other computational results published. It is shown that the computational results by the double body approximation agree well with the experimental results compared with those by the uniform Kelvin flow approximation.