• Journal of Ocean Engineering and Technology
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• v.11 no.2
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• pp.138-144
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• 1997

This is describes the automatic mesh generation on the ship hull surface. At first ship hull is defined as a cillocation of composite surface patches which satisfy the geometic continuity between adjoining patches by using Gregory surface method. Node points that would be mesh points are ganerated by considering the surface curvature. The triangulation of the node points is by the combination of Ohtsubo's method and Choi's one. After triangulation, shape improvement and quadrilateralization is done with specific criterin. An application to the actual ship and the results are shown.

• Journal of the Korean Professional Engineers Association
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• v.22 no.3
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• pp.5-13
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• 1989

A major problem of stopwatch time study is how to do for the accurate and consistent performance rating, which is one of the critical variables to determine the accuracy of work measurement and should be still dependent upon time observer's judgement. Therefore the time observer's ability for the performance rating is very important, and must be improved by correct training method and procedure. This paper developed a new benchmark and benchmark-observation method for the effective performance rating training of assembling and machining operations. The trainees' ability in the accuracy and consistency of the performance rating ,improved significantly after being trained by subject method. The percentage improvement in rating accuracy and consistency values was 34.7% and 49% respectively. In addition, benchmark-practice method for the performance rating training is not significant, so it is proofed that the skill of a certain operation is not important for the improvement of the rating ability.

• Phonetics and Speech Sciences
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• v.7 no.4
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• pp.17-25
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• 2015

For blind source separation of convolutive mixtures, FDICA(Frequency Domain Independent Component Analysis) algorithms are generally used. Since FDICA algorithm such as Sawada FDICA, IVA(Independent Vector Analysis) works on the frequency bin basis with a natural gradient descent method, it takes much time to converge. In this paper, we propose a new method to improve convergence speed in FDICA algorithm. The proposed method reduces the number of iteration drastically in the process of natural gradient descent method by applying a weighted inner product constraint of unmixing matrix. Experimental results have shown that the proposed method achieved large improvement of convergence speed without degrading the separation performance of the baseline algorithms.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.2
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• pp.363-373
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• 1995

In this study, a FE model tuning method using experimental modal data was suggested after examining all the published conventional methods. The idea of this method is introducing scale factors to maintain both the structural connectivity and the consistency in the corrected stiffness matrix which makes it always possible to interpret the stiffness elements with the corresponding physical configuration of the targeting structure. The scale factors are determined to minimize the objective function of eigen-properties. The proposed method was tested to determine the joint stiffness of a T shaped beam. The test results were also compared with the tuned stiffness obtained from a probed commercial package (SYSTUNE) and found that this method is very accurate and compatible.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1990.04a
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• pp.335-343
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• 1990

The traditional economic evaluation methods do not seem to consider derivative efforts-productivity improvement, quality improvement.-which may be occured by AMS introduction. Current evaluation methods are based on mass production with known characteristic and stable technology. Recently, expert suggest that these assumption-stable production and mass production-are realized to be a limited in substantial economic evaluation analysis. Therefore, the problem of traditional evaluation methods suggested in this thesis and decision in the case studies are derived using two complementary economic analysis methods-AHP method, modified economic evaluation model- and traditional evaluation method. After three methods are compared and evaluated in the view of practical economic evaluation, AHP method is intended to be introduced as a new economic evaluation method.

• Journal of information and communication convergence engineering
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• v.7 no.3
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• pp.323-329
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• 2009

In this paper, we propose the improvement method of the camera images regardless of exposure environments. By using a double-exposure method, we could improve camera images with clear recognition. We applied the improvement method on the mobile phone. For the feasibility of the proposed algorithm, we compared simulated camera images with the proposed method to conventional images by using auto-exposure image. Experimental results are also shown in this paper.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.578-582
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• 2009

Computer-Generated Hologram (CGH) is generally made by Fourier Transform. CGH is made by an optical reconstruction. Computer-Generated Pseudo Hologram (CGPH) is made up Complex Hadamard Transform instead of CGH which is made by the Fourier Transform. CGPH differs from CGH in point of view the possibility of optical reconstruction. There is an advantage that it cannot be optical reconstruction, in other word, physical leakage of the confidential information is impossible. In this paper, a binary image was converted in Complex Hadamard Transform, and CGPH was made. Improvement of the reconstructed image from CGPH is done by error diffusion method and iterative method. The result that the reconstructed image is improved is shown.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.235-237
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• 2018

In spite of the superiority of the sliding method in the building construction field, the AC induction motor servo control device is used as the power control technology in the building construction field in order to improve the problems of the hydraulic power control method, thereby contributing to the precision control and the productivity improvement. Based on Induction Motor Servo Controller, we proposed the development of a mobile sliding method using a complex combination of PC and MITY (MS) Servo.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.3B
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• pp.423-430
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• 2000

Future microcellular systems will require distributed network control. A packet-switched network is suitable for this requirement. The packet reservation multiple access(PRMA) is a Reservation-ALOHA like protocol for wireless terminals to transmit packet speech to a base station. It allows spatially distributed users in cellular systems to transmit packeted voice and data to a common base station using a shared channel. In the existing PRMA, the problem is that the voice packets may collide with the data packets due to simultaneous channel access. the problem may be a major performance degradation factor to a voice and data mixed system. We propose a new PRMA method that integrates voice and data traffic efficiently by resolving the collision problem between data and voice packets. The proposed PRMA method gives a performance improvement than the existing PRAMA method in terms of voice packet dropping probability and data delay characteristic. From analytic results, we can confirm that the proposed PRMA method show a performance improvement than the existing PRMA protocol.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.3
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• pp.101-110
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• 2018

In order to The certification of CMMI level is positioned as the most important part of software development company competitiveness. From that point, you will be able to find the various CMMI based process improvement activities of the companies in the above. This paper presents the activity method, such as organization, process application method for the CMMI based process improvement, through the field application. Based on that, this paper enables you to understand the model application method. And we also carry out the application case analysis of defect management with the schedule/effort analysis and colleague's check activity to show the improvement effectiveness, based on the quantitative analysis. And we present the problem and improvement part of real application. The result of this paper will be used to understand the effectiveness of quantitative process management, mentioned in the CMM. And furthermore, we also expect this paper to be useful for the organization to improve the process based on CMM in the future.