• Proceedings of the KSR Conference
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• 2000.11a
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• pp.613-619
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• 2000

This paper presents a mettled to reduce the number of conductors of catenary system for estimating line constants. Conductors of a catenary system are grouped and reduced. For example, the model representing the contact and the messenger conductors with a single equivalent conductor is. probably more realistic than assuming the two conductors completely separated, since they are generally connected by droppers every few meters. Therefore, this paper shows the method to reduce the number of conductors using electric circuit theory. To verify the results, we compared the equivalent line constants obtained by proposed method with those obtained by measurement.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.406-410
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• 1990

This paper presents an approximate analysis of the serial production lines using decomposition technique. A serial production line consists of a series of unreliable machines separated by finite buffers. The serial production line is evaluated by approximation method, the results of which are compared with those examined by the discrete time event simulation, based on this approximation method, a gradient technique is proposed, which improves the efficiency of an operation of production line through the re-allocation of buffers.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.8
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• pp.56-63
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• 1995

A new method is presented for the synthesis of lossy tapered transmission line having presecribed frequency characteristic in the passband. The theory of lossy case extends lossless cases suggested by Klopfenstein and others, and a special optimization process based on the Fourier transfrom pair and generalized Taylor's procedure is proposed for exact designs of frequency-dependent and distance-dependent lossy tapered line. The process is achieved by control of zero points of lobe-like input reflection coefficient. The validity of the suggested method is confirmed by synthesizing a lossy microstrip transformer and analyzing the simulation results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.3
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• pp.553-559
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• 1994

A coupled microstrip-slot line is analyzed using a full wave method in the specral domain. The characteristics of the coupled microstrip-slot line are obtained based on the Galerkin`s method. The characteristics of even mode by microstrip line and odd mode by slot line are calculated respectively. Especially the singularity of basis function is enforced to be considered with respect of modes. Numerical results are compared with available data and shown good agreement.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.318-323
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• 1992

The improvement of the production capability of multi PCB assembly line can not be simply done by improving the capacities of each assembly robot cells but must be done by controlling the production line effectively with the line host computer which controls over the whole assembly line. A real time production control, a real time model change and a real time trouble shooting compose the specific concepts of this technique. In this paper, we present and analyze the definition and application method of real time assembly concept. The meaning of real time model change, troubles and error sooting and its algorithm will be introduced. Also, the function of the host computer which is in charge of all of many different tasks mentioned above and the method are presented. The improvement of the productivity is mainly focused on the efficiency of multi-PCB production control. The importance of this aspect is gradually increasing, which we have presented the analysis and the solution.

• International Journal of Automotive Technology
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• v.6 no.1
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• pp.65-70
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• 2005

Pressure ripples, which are inevitably generated by a fluctuation of flow rate caused by a pump mechanism, include noises and vibrations in hydraulic pipeline. These noises and vibration deteriorate the stability and accuracy of hydraulic systems. The accumulator and hydraulic attenuator are normally used to reduce the pressure ripples. In this study, a parallel line is introduced to the hydraulic pipeline for the hydraulic system with a bent-axis piston pump as a method to reduce the pressure ripples. The dynamic characteristics of the hydraulic pipeline with a parallel line are analyzed by a transfer matrix in the frequency domain. The usefulness of the hydraulic pipeline with a parallel line was ascertained by experiment and simulation. The results from the experiment and simulation show that the hydraulic pipeline with a parallel line were effective in reducing the pressure ripples.

• Journal of Korea Multimedia Society
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• v.7 no.4
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• pp.459-466
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• 2004

In this paper, an effective skeleton method is proposed in order to obtain an enhanced digital image of skeleton line. The binary image using the threshold values is applied in the preprocessing stage and then the modified parallel processing method is applied to obtain the improved image of skeleton line. The existing skeleton methods are Rutovitz, Steiabelli and other five skeleton methods. In the digital process of skeleton line, the major problem caused by these methods is elongated lines and noise branches of the processed image. In this study, however, such noises are deleted first by the modified parallel processing step of the proposed method. Then a pixel is compared to its eight neighbor pixels. if its neighbor pixels are in one of the eight conditions, the central pixel is deleted. As a result, the quality of the skeleton is better then those produced by the existing skeleton methods.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.6 no.4
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• pp.11-19
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• 1995

In this paper, the Finite Difference Time Domain (FDTD) method is used to analyse the characteristics of the coaxial line transmission coefficent, shielding effectiveness, and compared to results of the moment method. The excitation mode of the Gaussian pulse is assumed to be a TEM-mode instead of the TE or TM-mode and in order to eliminate the reflected wave with in short length of the line. Calculated value of shielding effectiveness of the coaxial line by the FDTD are in good agreement with the results of the moment method.

• Journal of Sasang Constitutional Medicine
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• v.4 no.1
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• pp.107-148
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• 1992

The definitions of Four Constitution (Tae-Yang-In, So-Yang-In, Tae-Eum-In, So-Eum-In) in Four-Beginning-Theory (四端論) and Distribution-Theory (擴充論) were morphologically diagrammatized. the method of measuring the five parts came from the diagrams. The five parts are the followings; Top-Line is the distance between Rt. & Lt.Shoulders. Bosom-Line is the horizontal distance passing through the Rt. & Lt.nipples. Stomach-Line is the horizontal distance passing through the Rt. & Lt. acupuncture point Bool-Yong (不容穴). Navel-Line is the horizontal distance passing through the navel. Bottom-Line is the distance between the Rt.& Lt. anterior superior iliac spines. According to it, 311 people were measured in the clinic. Through the measured numerical values, to find out the objective propriety of the morphological diagrammings and the discriminating ability of Four Constitutions by the method of measuring the five, the author tried this study and got the following results. 1. On the ground of the Internal Organs-Theory (臟腑論), the definitions of Four Constitutions were classified and diagrammatized step by step and it was possible to draw the morphological graphs satisfying the reasonable condition objectively. 2. It was found that the graphings by Mean, Standard Deviation and 95% Confidence Interval for mean of the numerical values of five measured parts and the morphological diagrammings of the definitions in Four-Beginning Theory and Distribution-Theory drove to the same figures. 3. Through the method of the Analysis of variance and the Discriminant Analysis, it was discovered that the measured numerical values of five parts could distinguish the Four Constitutions. 4. Tae-Yang-In has the longest Top-Line and the shortest Bottom-Line. The Mean head of Confidence Interval from Top to Bottom is downwardly decreased at the rate of 3.7, 1.5, 1.8, 3.4. 5. So-Yang-In has the longest Top-Line and the shortest Bottom-Line. The Mean head of confidence Interval from Top to Bottom is downwardly decreased at the rate of 2.3, 1.5, 1.5, 1.1. 6. Tae-Eum-In has the longest Navel-Line. The Mean head of Confidence Interval from Navel to Top is upwardly decreased at the rate of 0.5, 0.4, 2.5 and downwardly decreased at the rate of 2.7 between Navel and Bottom. 7. So-Eum-In has the longest Bottom-Line. The Mean head of Confidence Interval from Bottom to Top is upwardly decreased at the rate of 1.1, 1.1, 1.8, 2.3. From the above findings, it was possible to draw the morphological graphings satisfying the objectively reasonable conditions in the definitions of Four-Beginning-Theory and Distribution-Theory and it was proved that the results of the Positive Analysis, carried with the measured numerical values of five parts from the diagramming, could show the objective propriety of the morphological graphings and the discerning ability of Four Constitutions by the method of measuring the five parts.

• Communications of Mathematical Education
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• v.31 no.1
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• pp.85-101
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• 2017

The purpose of this study is to investigate how elementary school students understand and use the number line relating number concept and what is the main problem in the learning process. For the efficient achievement of this purpose, we investigated how the number line metaphor is related to the number concept and considered the role of the number line on Freudenthal's number concept teaching theory. The test conducted to find the degree of understanding and difficulty on using the number line by actual elementary school students consisted of two questions ; to find appropriate number corresponding to the given number on the number line and to identify contents of chapters about the use of number line on each grade. It was found that many students couldn't solve the problem represented by the number line though they could solve the problem represented by other ways such as number track and pictures. The only difference between the two problems was the way of representation, and they had same contents and structure. This study tried to figure out the meaning of this phenomenon. Also, by using various teaching-learning method (number track, pictures, empty number line, and double number line etc.), this study was aimed to provide the way to help learning 'related number concept' and to solve the difficulty on understanding the number line.