• Macromolecular Research
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• 제17권7호
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• pp.499-505
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• 2009

General, fast, and efficient stitching methods are presented for the synthesis of Fr$\acute{e}$chet-type dendrimers with linear units at a core, as a preliminary investigation for the synthesis of dendritic-linear-dendritic materials. The synthetic strategy involved an inexpensive, 1,3-dipolar, cycloaddition reaction between an alkyne and an azide in the presence of the Cu(I) species, which is known as the best example of click chemistry. The linear core building blocks, 1,7-octadiyne and 1,6-diazidohexane, were chosen to serve as the alkyne and azide functionalities for dendrimer growth via click reactions with the azide and alkyne-dendrons, respectively. These two building blocks were employed together with the azide- and alkyne-functionalized Fr$\acute{e}$chet-type dendrons in a convergent strategy to synthesize two kinds of Fr$\acute{e}$chet-type dendrimers with different linear core units. This comparative efficiency of the click methodology supports the fast and efficient synthesis of dendritic-linear-dendritic materials with the tailor made core unit.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.917-923
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• 2005

Scheduling is one of the main functions in construction project to determine the sequence of activities necessary to complete a project. The scheduling techniques provide important information crucial to a project's success. Highway construction project the paving activity can be considered a linear activity. Linear scheduling technique may be better suited for linear projects than other scheduling techniques. A new type of scheduling in linear project is calling Linear Scheduling Model (LSM). The Project monitoring and controlling is very ease to identify that all the stage of linear project and have more advantages.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제24권2호
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• pp.445-474
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• 2010

중학교 1학년 학생들의 일차방정식에 대한 풀이과정에 변화가 있는지를 알아보기 위하여 일차방정식을 학습한 후 1차 조사를 하고, 5개월이 지난 후에 2차 조사를 실시한 결과는 다음과 같다. 첫째, 1차 조사와 2차 조사 간의 정답 비율의 차이를 알아보기 위하여 McNemar검정을 실시한 결과, 유형A의 문항 x+4=9에서 $p=.035^a$, 문항 $x+\frac{1}{4}=\frac{2}{3}$에서 $p=.012^a$로 나타났으며, 유형B의 문항 x+3=8에서 $p=.012^a$, 문항 6(x+20)=20에서 $p=.035^a$으로 나타났다. 둘째, 1차 조사에서 문제 유형A와 유형B의 풀이과정을 올바르게 표현하지 못하였던 학생들 중에 2차 조사에서 올바르게 표현한 학생들이 있는 반면, 1차 조사에서 풀이과정을 올바르게 표현한 학생들 중에 2차 조사에서 오류를 범하는 학생들이 나타났다. 셋째, 모든 문항에 대하여 일차방식의 풀이과정을 올바르게 표현하는 학생들이 있는 반면, 몇 개 문항은 올바르게 표현하고 몇 개 문항은 그렇지 못한 학생들이 있었다. 결론적으로, 주어진 모든 문항에 대한 풀이 과정을 올바르게 표현하였더라도 또 다른 문항이 주어졌을 때 그 문항의 풀이과정에서 올바른 표현을 할 수 있다고 예견하기가 어렵다는 것이다. 논문에서 조사한 세 가지 유형(유형A, 유형B, 유형C)에 대한 학생들의 반응을 분석한 결과에 따르면, 이 세 가지 유형의 문제 풀이과정을 분석함으로써 어떤 학생이 일차방정식의 풀이과정을 올바르게 표현할 수 '있는지', '없는지'를 판단할 수 있다는 것이다.

• 대한전기학회논문지
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• 제35권12호
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• pp.567-572
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• 1986

In this paper, a new type of step motor with two degree of mechanical freedom, which is named rotary-Linear Step Motor(RLSM), is presented. Its rotor axis can perform linear and rotary motions either separately or simultaneously. This paper discribes the design of RLSM using finite element method in which the magnetic saturation effect of the iron core is taken into account. The design parameters such as torques, forces and inductances are obtained from the computed magnetic vector potentials. A new type of Rotary-Linear Step Motor was constructed. The calculated parameters agree well with measurements.

• 응용통계연구
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• 제7권1호
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• pp.75-82
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• 1994

일반화 선형모형에서도 회귀모형에서와 마찬가지로 다공선성이 존재할 경우 여러가지 문제가 발생한다. 이를 극복하기 위한 한가지 방법으로 능형형태의 추정량과 그의 축소 모수를 결정하는 방법에 대하여 다루었다.

• Journal of the Korean Statistical Society
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• 제34권4호
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• pp.281-295
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• 2005

We investigate the rate of convergence of the distribution of the maximum likelihood estimator (MLE) of an unknown parameter in the drift coefficient of a stochastic process described by a linear stochastic differential equation driven by a fractional Brownian motion (fBm). As a special case, we obtain the rate of convergence for the case of the fractional Ornstein- Uhlenbeck type process studied recently by Kleptsyna and Le Breton (2002).

• 대한수학회보
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• 제45권4호
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• pp.763-780
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• 2008

An Ostrowski type inequality is developed for estimating the deviation of the integral mean of an absolutely continuous function, and the linear combination of its values at k + 1 partition points, on a segment of (real) linear spaces. Several particular cases are provided which recapture some earlier results, along with the results for trapezoidal type inequalities and the classical Ostrowski inequality. Some inequalities are obtained by applying these results for semi-inner products; and some of these inequalities are proven to be sharp.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.634-637
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• 2002

Transducer for linear ultrasonic motor with symmetric and anti-symmetric modes was studied. The transducer was composed of two Langevin-type vibrators. In order to excite two vibration modes, Two Langevin-type vibrators must have 90-degree phase difference with each other. As result, tip of transducers moves in elliptical motion. In this paper, vibration shape of transducer was simulated and The resonant frequency and maximum displacement were calculated using the FEA (Finite Element Analysis).

• Journal of Electrical Engineering and Technology
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• 제7권3호
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• pp.342-348
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• 2012

This paper presents a moving-magnet type linear actuator designed by using flux concentration type permanent magnet arrangement, which can generate higher magnetic flux density in air-gap. In this construction, detent force which is induced by both slot-effect and end-effect becomes larger due to strong attractive forces. To reduce cogging force we have employed a modular mover structure of two magnetic pole sections connected with a center yoke. The improved motor performance is demonstrated with the prototype machine.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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• pp.29-32
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• 1998

A plate-type ultrasonic linear motor using longitudinal and bending multi-vibration mode was designed and fabricated for card-forwarding device. The rotor consisted of piezoelectric ceramic plate and elastic materials. The performances of the motor were measured. As the experimental results, no-load speed of the motor was 0.6 m/s at 80 V in applied voltage. Starting torque was 1.4 mNm and maximum efficiency was 1.2 %.