• Macromolecular Research
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• v.17 no.7
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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.

• International conference on construction engineering and project management
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• 2005.10a
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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.

• Communications of Mathematical Education
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• v.24 no.2
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• pp.445-474
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• 2010

The results of performing first survey after learning linear equation and second survey after 5 months to find out whether there is change in solving process while seventh grade students solve linear equations are as follows. First, as a result of performing McNemar Test in order to find out the correct answer ratio between first survey and second survey, it was shown as $p=.035^a$ in problem x+4=9 and $p=.012^a$ in problem $x+\frac{1}{4}=\frac{2}{3}$ of problem type A while being shown as $p=.012^a$ in problem x+3=8 and $p=.035^a$ in problem 5(x+2)=20 of problem type B. Second, while there were students not making errors in the second survey among students who made errors in the solving process of problem type A and B, students making errors in the second survey among the students who expressed the solving process correctly in the first survey were shown. Third, while there were students expressing the solving process of linear equation correctly for all problems (type A, type B and type C), there were students expressing several problems correctly and unable to do so for several problems. In conclusion, even if a student has expressed the solving process correctly on all problems, it would be difficult to foresee that the student is able to express properly in the solving process when another problem is given. According to the result of analyzing the reaction of students toward three problem types (type A, type B and type C), it is possible to determine whether a certain student is 'able' or 'unable' to express the solving process of linear equation by analyzing the problem solving process.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.35 no.12
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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.

• The Korean Journal of Applied Statistics
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• v.7 no.1
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• pp.75-82
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• 1994

It is known that collinearity among the explanatory variables in generalized linear models inflates the variance of maximum likelihood estimators. A ridge-type estimator is presented using penalized likelihood. A method for choosing a shrinkage parameter is discussed and this method is based on a prediction-oriented criterion, which is Mallow's $C_L$ statistic in a linear regression setting.

• Journal of the Korean Statistical Society
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• v.34 no.4
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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).

• Bulletin of the Korean Mathematical Society
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• v.45 no.4
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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.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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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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• v.7 no.3
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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.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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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 %.