• Journal of Environmental Impact Assessment
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• v.15 no.1
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• pp.35-43
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• 2006

The eutrophication in lakes is caused by the inflow of excessive nitrogen and phosphorus, which are not only pollutants to reduce the value of water resource but also nutrients for algae growth that debases water quality. Several methods have been used to judge the eutrophication grades of lakes, but the judgment results can be different with one another even under same coditions because each method is different in judgment items and their standards. A method for overcoming the problem with the judgment of eutrophication grades is, therefore, developed in this study with the application of fuzzy theory. This method allows decision makers to represent the uncertainties (differences) of results by the existing judgment methods and also incorporate associated uncertainties directly into the judgment process, so the judgment results can be made that are more realistic and consistent than those made without taking uncertainty in account.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.6
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• pp.100-108
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• 1993

In this paper, noticing the point of human's ability which appropriately cope with vague conditions, we design fuzzy traffic signal light controller similar to human's distinction ability and decide the optimum cycle most suited to any traffic junction using fuzzy identification algorithm. In this study, for the control output decision process we design fuzzy controller better than electronic vehicle actuated controller in performance. We propose the cycle decision method which is not limited by the variance of traffic junction vehicle number through overcoming the limit of Webster's method which is adopted by the fixed cycle controller. Simulated experimental results show that fuzzy controller and fuzzy identification algorithm are better than the existing electronic vehicle actuated controller and fixed cycle controller in delay time per vehicle.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.165-166
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• 2006

By using a ceramic material with dielectric constant 37, the miniature waveguide ceramic bandpass filter was implemented. The proposed waveguide ceramic bandpass filte was based on the mode matching method and simulation process. For overcoming high power, We used the connector at in/output of waveguide ceramic bandpass filte. The result of power test satisfied the 30W. The product will used as a parts of repeater for wibroband.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.4
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• pp.439-449
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• 1998

In this paper, error performance of DS-CDMA communication system has been analyzed in a radio channel which is characterized by multi-user interference (MUI). Also, performance improvement has been obtained by both numerical analysis and simulation techniques when 3-element array antenna and co-channel interference (CCI) canceller are employed as a means for overcoming an MUI effect. The MUI was modelled as a gaussian random process. In array antenna scheme we only considered a directivity of antennal. The results show that there is a substantial enhancement in performance by employing an array antenna or a CCI canceller. CCI canceller gives better improvement in performance than the array antenna with D=2.67. Additional improvement can be obtained when the array antenna and the CCI canceller are adopted in cascade form. In this case the error performance approaches that of AWGN environment.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.11
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• pp.935-940
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• 2002

For robot navigation and visual reconstruction, structure from motion (SFM) is an active issue in computer vision community and its properties arc also becoming well understood. In this paper, when using stereo image sequence and direct method as a tool for SFM, we present a new method for overcoming bas-relief ambiguity. We first show that the direct methods, based on optical flow constraint equation, are also intrinsically exposed to such ambiguity although they introduce robust methods. Therefore, regarding the motion and depth estimation by the robust and direct method as approximated ones. we suggest a method that refines both stereo displacement and motion displacement with sub-pixel accuracy, which is the central process f3r improving its ambiguity. Experiments with real image sequences have been executed and we show that the proposed algorithm has improved the estimation accuracy.

• Journal of the Korean Chemical Society
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• v.59 no.4
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• pp.308-319
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• 2015

As a follow-up study to identify references for threshold concepts in science, 20 high school chemistry teachers were interviewed. Seven concepts were identified as threshold concepts. The data revealed that teachers overcome the thresholds while they are teaching as well as learning during their school years. This explains that the mastery experience of threshold concepts involve not only the process of creating subject matter knowledge of a learner but also the reflection on or preparation for teaching. Hence, the current study proposes that a strong relationship exists between the mastery experience of threshold concepts and the development of teachers’ pedagogical content knowledge (PCK). In this regard, findings from this study will provide valuable information to understand the nature of threshold concepts and suggests the value of mastery experience of threshold concepts in terms of PCK development.

• Journal of the Korea Furniture Society
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• v.17 no.1
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• pp.73-81
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• 2006

Since early times, paper has been the leading means of expression in human civilization. Along with the development of languages, people have used paper as their major intermediation measures to flourish the culture. At this point of time when studies in latest design are various and abundant, these fixed ideas on paper should be eliminated first for inventive thinking and freedom of expression. Because breaking the established notion helps to diversify the function of paper. We can see furniture made of paper come in useful to our ancestors in their daily life with the development of "Hanjiquot;. Each piece of paper furniture had its own function and beauty depending on processing method. Not only has been used for materials of basic modeling in the process of modern furniture designing, paper has also been used for the main material for the purpose of a new trial. If we try to find out the ways to take diverse characteristics of paper and develop them, while overcoming the defects of the material, paper has great potentiality for many kinds of use in furniture industry.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.33-33
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• 2010

Recently, a self-organizing process that occurs during the anodization of aluminum in acidic electrolytes has attracted a vast amount of research attentions, coupled with the ever-increasing demand for the development of effective, inexpensive and technologically simple methods for the synthesis of low-dimensional nanostructures over a macroscopic area overcoming many of the drawbacks of conventional lithographic techniques. In this presentation, recent progress in the fabrication of ordered nanoporous anodic aluminum oxide (AAO), including conventional anodization techniques, newly developed pulse anodization, hard anodization processes, and generic approaches to three-dimensional pore structures with periodically modulated diameters. Discussion will also cover the applications of AAO for the development of structurally well-defined extended arrays of low-dimensional nanostructures, such as nanodots, nanotubes, and nanowires, which could be model systems in investigating a diverse range of research problems in chemistry and physics and also be starting materials in realizing advanced electronic devices.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.1046-1050
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• 2005

Micro Cellular Plastics create a sensation at polymer industrial for lowering product cost & overcoming a lowering of mechanical intensity. There Is much development from injection molding pans but Extrusion parts is slow. This research is MCPs Extrusion parts, It is basis experiment for Process to make beads that is basis raw material of Package used most by shock mitigative of industry.

• The Mathematical Education
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• v.48 no.3
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• pp.213-234
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• 2009

College students have a diverse educational background with the recent multiplicity in university admissions standards and procedures. As a result, their mathematical preparation and performance varies widely. Teaching calculus to such a diverse student group is a demanding task. Differentiated curriculum has been conducted for the university calculus course in Yonsei university for the past five years. A case study on the differentiated curriculum in Yonsei university is presented for the curriculum improvement. With its ideal purpose, the differentiated curriculum has created issues and problems in practice. As an alternative to the ideal differentiated curriculum, this study shows that a computer-based approach using a numerical software could give aids to overcoming the difficulty of inadequately prepared students in the learning process while mathematically sophisticated students could keep interested in the course. This study also presents the useful topics in calculus that can be implemented for computer-based calculus education and provides guidelines for the effective usage.