• Journal of Electrical Engineering and Technology
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• v.13 no.4
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• pp.1644-1654
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• 2018

Eigenvalue distributions for a periodic metal-insulator-metal waveguide, classified into the point spectrum and the discretized continuous spectrum (DCS), are investigated as functions of frequencies, gap widths, and periods. Muller's method is suggested for solving exact eigenvalues, and we propose the scheme for finding proper initial values in the Muller's method by considering only ${\Re}e({\varepsilon}_r)$ in the dispersion equation. We then find that anti-crossing behavior, repulsive effect between the point spectrum and the DCS, becomes stronger when the real parts of the roots in the point spectrum have smaller values. Finally, we examine the transmittances of a single subwavelength slit for real metals using the mode matching technique. The transmittances in real metals similarly follow those of the perfect electric conductor (PEC) at low frequencies, while the patterns at higher frequencies begin to differ from the PEC.

• Journal of Korean Society of Water and Wastewater
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• v.33 no.6
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• pp.457-467
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• 2019

Because non-point source pollution is very closely related to hydrological characteristics, its importance is highly emphasized nowadays along with accelerating climate change. Especially for Korea, the non-point source pollution and its control are entirely depending on runoff, precipitation, drainage, land use or development, based on geographical and topographical reasons of Korea. Many studies reported the physical (e.g., apparatus- and natural-type facilities, etc.) and chemical methods (e.g., organic and inorganic coagulants, etc.) of controling non-point pollutant source pollution, however, those are needed to be reconsidered along with climate change causing the unexpected patterns and amounts of precipitation and strengthen complexity of social community. The objectives of this study are to assess recent situations of non-point source pollution in Korea and its control means and to introduce possible effective ways of non-point source pollution against climate change in near future.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.18 no.2
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• pp.75-84
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• 2014

Objectives Eyes, one of visual inspection regions, present important clues to pathological patterns including deficiency and excess patterns to the clinicians. The purpose of this study was to develop Eyes Inspection Questionnaire (EIQ) and to examine which items among the EIQ were more predictive of clinicians' determination for the deficiency and excess patterns. Methods Nine questionnaire items for Visual Inspection of Eyes were extracted through the literature review. These items were presented to the 4 Korean medical doctors who are specialized in visual inspection to conduct the Delphi method. The Korean medical doctors were asked to rate the importance of each items for the corresponding Visual Inspection of Eyes, using a Likert 5-point scale(the 3 points of importance as a cut-off point). Then, out of 75 photographs submitted to the Society of HyungSang Medicine in 2009, 30 portrait pictures were selected as samples. The samples were copied to make 60 sample pictures, and then randomly assigned to 4 clinicians. The 4 clinicians evaluated the 60 samples for excess and deficiency of the eyes and were asked to check the 6 questionnaire items. The results were recorded as 5-points-scale, and their average and standard deviations were calculated. Intra- class reliability test and multi regression test were performed using SPSS 13. Results Intra-class correlation coefficient (ICC) was between 0.750 to 0.841 (P<0.05). Indices for visual inspection of the eyes were: endowment of the bone structure around the eyes; brightness of the eyes; upward deviation of the eyes; eye shapes; and definition of iris. 76.92% of deficiency symptom patterns and 86.42% of the excess symptom patterns matched the patterns predicted by the visual inspection of the eyes, according to the frequency analysis. According to the multiple regression analysis, were significantly related to the excessive symptoms, and to the deficiency symptoms. Conclusion This study is the first attempt of development for checklist of excess and deficiency of Visual Inspection of Eyes and quantitative measurement of excess and deficiency using the Visual Inspection of Eyes by the visual inspection experts. Still, additional studies are needed regarding the relationship visual inspection methods have with existing standards of diagnosis.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.470-473
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• 2002

A communication-aid circuit to detect eye-gazed patterns is proposed in this paper. The circuit is an analog-digital mixed system. By determining the direction of eye-gazed pattern, the circuit detects an eye-gazed pattern from 2-dimensional arrayed patterns on a syllabary. Different from conventional systems, the syllabary is moved to overlap the eye-gazed pattern with the center coordinate of screen. Thus, the proposed circuit can avoid a complex calculation of the distance between the eye-gazed point and the center coordinate. Furthermore: an economical size of hardware can be provided since no full-adders are required by employing floating-gate MOSFBT's. The validity of the cricuit design is confirmed by computer simulations. Furthermore, to implement onto an IC chip, the layout design is performed by using a CAD tool, MAGIC.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.12
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• pp.1486-1491
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• 1999

This paper presents a method of recognizing high impedance fault(HIF) of electrical power systems and classifying fault patterns based on chaos attractors. Two dimensional chaos attractors are reconstructed from neutral point current waveforms. Reliable features for HIF pattern classification are obtained from the chaos attractors. Radial basis function network, trained with two types of HIF data generated by the electromagnetic transient program and measured form actual faults. The RBFN successfully classifies normal and the three types of fault patterns according to the features generated from the chaos attractors.

• Journal of the Korean Home Economics Association
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• v.40 no.3
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• pp.21-40
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• 2002

The aim of this interdisciplinary study is to understand the relationship between the social behavior patterns and space elements, specially micro-housing sociological point of view. It analyzed korean typical floorplans in the apartment housing, focused on the 4-criteria contact or isolation between the individual persons, communication between the generations, hierarchy of the gender and socialization with neighbourhood. It determinate concrete space elements involved correspondent factors with users' social behavior. By reviewing those factors found, it is suggested also the planning concept, that response users' social orientation. As the practical alternatives, some prototypes have been developed not only for improvement of housing plans, but also for resonable housing supply and sustainable usage.

• Journal of Powder Materials
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• v.19 no.5
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• pp.343-347
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• 2012

In this study, an oxygen plasma treatment was used as a low temperature debinding method to form a conductive copper feature on a flexible substrate using a direct printing process. To demonstrate this concept, conductive copper patterns were formed on polyimide films using a copper nanoparticle-based paste with polymeric binders and dispersing agents and a screen printing method. Thermal and oxygen plasma treatments were utilized to remove the polymeric vehicle before a sintering of copper nanoparticles. The effect of the debinding methods on the phase, microstructure and electrical conductivity of the screen-printed patterns was systematically investigated by FE-SEM, TGA, XRD and four-point probe analysis. The patterns formed using oxygen plasma debinding showed the well-developed microstructure and the superior electrical conductivity compared with those of using thermal debinding.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.1-1
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• 2000

The interaction of light with periodic patterns generates beautiful color patterns and interesting applications. The basic equation for understanding this phenomena is the grating equation. It tells us the angles, relative to a perpendicular to a grating with a specific period, into which light of a specific wavelength will be diffracted. But what it does not tell us is how much light will be directed into the various "orders" of the grating. It was found that by controlling the shape of the diamond point used to cut the periodic structure into the substrate, a traditional grating could be made to direct most of the light diffracted from it into a single order. This type of grating is referred to as a "blazed" grating. (omitted); grating. (omitted)

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1481-1484
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• 1997

This paper describes a electrical tree simulation by fractal theory. Tree patterns produced by computer simulation with random numbers were studied from the point of view of fractal dimension. Tree patterns have a variety of shapes such as branch-like, bush-like, and quasi-bush-like trees. The patterns are determined by origins and probability ratio. The fractal dimensions have been measured a function of discharge number.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.136-137
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• 2017

Maximum power point tracking (MPPT) under partial shading condition (PSC) is a challenging process in the PV array system. The shaded PV panel makes different peak patterns on the P-V curve and misguides the MPPT algorithm. Various kinds of global MPP (GMPP) detecting algorithms are used to overcome this issue. Generally, too frequent execution of GMPP tracking algorithm reduces the achievable power of PV panel due to time spent on the scanning process. Thus, partial shading detection algorithm is essential for efficient utilization of solar energy source. While conventional method only detects fast shading patterns, the proposed algorithm always shows superb performance regardless of the speed of partial shading patterns.