• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.5
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• pp.748-754
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• 2008

The general capacitor placement problem is a combinatorial optimization problem having an objective function composed of power losses and capacitor installation costs subject to bus voltage constraints. In this paper, a global optimization technique, which employing the chaos search algorithm, is applied to solve optimal capacitor placement problem with reducing computational effort and enhancing global optimality of the solution. Chaos method in optimization problem searches the global optimal solution on the regularity of chaotic motions and easily escapes from local or near optimal solution than stochastic optimization algorithms. The chaos optimization method is tested on 9 buses and 69 buses system to illustrate the effectiveness of the proposed method.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.403-405
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• 2003

In this paper, we applied a chaos search method for feeder reconfiguration problem in unbalanced distribution system. Chaos method, in optimization problem, searches the global optimal solution on the regularity of chaotic motions and more easily escapes from local or near optimal solution than stochastic optimization algorithms. The chaos search method applied to the IEEE 13 unbalanced test feeder systems, and the test results indicate that it is able to determine appropriate switching options for global optimum configuration.

• Journal of Life Science
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• v.17 no.8 s.88
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• pp.1068-1074
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• 2007

Parvalbumin occurs in various types of cells in the retina. We previously reported parvalbumin distribution in the inner nuclear layer of bat retina. In the present study, we identified the parvalbumin-immunoreactive neurons in the ganglion cell layer of the retina of a bat, Rhinolophus ferrumequinum, and investigated the distribution pattern of the labeled neurons. Parvalbumin immunoreactivity was found in numerous cell bodies in the ganglion cell layer. Quantitative analysis showed that these cells had medium to large-sized somas. The soma diameter of the parvalbumin-immunoreactive cells in the ganglion cell layer ranged from 12.35 to 19.12 ${\mu}m$ (n=166). As the fibers in the nerve fiber layer were also stained, the majority of parvalbumin-immunoreactive cells in the ganglion cell layer should be medium to large-sized retinal ganglion cells. The mean nearest neighbor distance of the parvalbumin-immunoreactive cells in the ganglion cell layer of the bat retina ranged from 59.57 to 62.45 ${\mu}m$ and the average regularity index was 2.95 ${\pm}$ 0.3 (n=4). The present results demonstrate that parvalbu-min is expressed in medium to large-sized retinal ganglion cells in bat retina, and they have a well-or-ganized distributional pattern with regular mosaics. These results should be important as they are applicable to a better understanding of the unsolved issue of a bat vision. This data will help to provide fundamental knowledge for the better understanding of the unique behavioral aspects of bat flight maneuverability.

• Steel and Composite Structures
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• v.44 no.5
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• pp.619-632
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• 2022

There are numerous structural details (Longitudinal beam, web plate, U-ribs and I-ribs) in the top and bottom plates of steel box girders, which have significant influences on the longitudinal stress (normal stress) distribution. Clarifying the influence of these structural details on the normal stress distribution is important. In this paper, the ultra-wide steel box girder with large cantilevers of the Jinhai Bridge in China, which is the widest cable-stayed bridge in the world, has been analyzed. A 1:4.5 scale laboratory model of the steel box girder has been manufactured, and the influence of structural details on the normal stress distribution in the top and bottom plates for four different load cases has been analyzed in detail. Furthermore, a three-dimensional finite element model has been established to further investigate the influence regularity of structural details on the normal stress. The experimental and finite element analysis (FEA) results have shown that different structural details of the top and bottom plates have varying effects on the normal stress distribution. Notably, the U-ribs and I-ribs of the top and bottom plates introduce periodicity to the normal stress distribution. The period of the influence of U-ribs on the normal stress distribution is the sum of the single U-rib width and the U-rib spacing, and that of the influence of I-ribs on the normal stress distribution is equal to the spacing of the I-ribs. Furthermore, the same structural details but located at different positions, will have a different effect on the normal stress distribution.

• Journal of the Korean Dietetic Association
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• v.10 no.3
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• pp.364-374
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• 2004

This Study was carried out to investigate dietary life and recognition of diet related factors in elemantary, middle and high school students. This study was surveyed by questionnaires and data were analyzed by SPSS program. Comparative analysis was conducted according to three school student groups(elementary childrens, middle school students, high school students). The subjects were 1,886 school students(female 893, male 959) of 51 schools in nationalwide region. The Distribution of subjects was elementary school childrens 544, middle school students 661 and high school students 681. The results are summarized as follows. Only Sixty percent of the subjects had breakfast regularly. About one forth of the subjects had the habit of skipping breakfast or eating 2-3 times per week. Pricipal reasons of skipping breakfast were 'busy'(50.7%) and 'not delicious or poor appetite'(31.0%). Regularity of having breakfast and reasions of skipping breakfast were significant differences according to school student groups(p<0.001 respectively). About half of the subjects didn't have sufficient amounts in breakfast. Most subjects(92.1%) had lunch regularly by virtue of school lunch service. One forth of the subjects had dinner irregularly. Pricipal reasons of skipping dinner were 'not delicious'(41.7%), 'busy'(15.1%) and 'weight loss'(14.3%). Regularity of having dinner and reasons of skipping dinner were significant differences according to school student groups(p<0.01, p<0.001 respectively). The most delicious meal was dinner in 56.7% of the subjects and lunch in 37.1% of the subjects. There was significant difference in recognition of most delicious meal according to school student groups(p<0.001). Only ten percent of the subjects thought that nutrition education was not needed. Diettitian was recognized as nutrition educator in sixty percent of the subjects. Only 5 percent of the subject recognized teacher as nutrition educator. There were not significant differences in most delicious meal and nutrition educator according to operation type of school lunch service. The findings suggested continuous attention and guidance for healthy dietary life and necessity of nutrition education for both school students and their parents.

• Journal of Biomedical Engineering Research
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• v.19 no.6
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• pp.585-593
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• 1998

In Fourier magnetic resonance imaging (MRI), the number of phase encoded signals is often reduced to minimize the duration of the studies and maintain adequate signal-to-noise ratio. However, this results in the well-known truncation artifact, whose effect manifests itself as blurring and ringing in the image domain. In this paper, we propose a new regularization method in the context of a Bayesian framework to reduce truncation artifact. Since the truncation artifact appears in t도 phase direction only, the use of conventional piecewise-smoothness constraints with symmetric neighbors may result in the loss of small details and soft edge structures in the read direction. Here, we propose more elaborate forms of constraints than the conventional piecewise-smoothness constraints, which can capture actual spatial information about the MR images. Our experimental results indicate that the proposed method not only reduces the truncation artifact, but also improves tissue regularity and boundary definition without oversmoothing soft edge regions.

• The Korean Journal of Food And Nutrition
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• v.19 no.4
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• pp.502-514
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• 2006

This Study was carried out to find out regional differences about dietary life and factors associated with meal of school children and adolescents between urban and rural area. Forty students from each of the nationwide 51 schools of three different levels(elementary, middle and high school) were surveyed by self-developed questionnaires. Total of 1,886 questionnaires (1,243 from urban and 681 from rural) were collected and distribution of subjects was 544 from elementary school, 661 from middle school, and 681 from high school. The results were summarized as follows. BMI and degree of satisfaction on body weight of elementary and middle school subjects were not significantly different between urban and rural area. But there were significant regional differences in $BMI(urban\;21.2{\pm}3.0,\;rural\;20.5{\pm}2.8,\;p<0.05)$ and degree of satisfaction on body weight of high school subjects(p<0.001). Elementary(p<0.01) and middle school(p<0.05) subjects in urban area had exercised more frequently than those in rural area. Regularity of having breakfast was not significantly different between urban and rural area at each of three different levels of school. Most subjects(urban 92.2%, rural 92.1%) had lunch regularly by virtue of school lunch service. Regularity of having dinner of elementary(p<0.01) and high school subjects (p<0.01) was significantly different between urban and rural area. Reason for skipping dinner of high school subjects was significantly different between urban and rural area (p<0.05). The most delicious meal was dinner for 51.8% of the urban high school subjects and lunch for 51.7% of the rural subjects. Only one third had intention of participating in school breakfast program regardless of region and levels of school. The findings suggested that nutrition education programs for school children and adolescents include different strategy according to region and levels of schools.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.4
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• pp.1866-1883
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• 2019

As the youngest branch of information hiding, network covert timing channels conceal the existence of secret messages by manipulating the timing information of the overt traffic. The popular model-based framework for constructing covert timing channels always utilizes cumulative distribution function (CDF) of the inter-packet delays (IPDs) to modulate secret messages, whereas discards high-order statistics of the IPDs completely. The consequence is the vulnerability to high-order statistical tests, e.g., entropy test. In this study, a rich security model of covert timing channels is established based on IPD chains, which can be used to measure the distortion of multi-order timing statistics of a covert timing channel. To achieve rich security, we propose two types of covert timing channels based on nested lattices. The CDF of the IPDs is used to construct dot-lattice and interval-lattice for quantization, which can ensure the cell density of the lattice consistent with the joint distribution of the IPDs. Furthermore, compensative quantization and guard band strategy are employed to eliminate the regularity and enhance the robustness, respectively. Experimental results on real traffic show that the proposed schemes are rich-secure, and robust to channel interference, whereas some state-of-the-art covert timing channels cannot evade detection under the rich security model.

• Proceedings of the IEEK Conference
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• 2000.11d
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• pp.9-12
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• 2000

This paper proposes an improved image illumination estimation method based on the conventional color constancy algorithm. The most important process of color constancy algorithm is the estimation of the spectral distributions of illuminant of an input image. To estimate of the spectral distributions of illuminant of an input image, we use the brightest pixel values and the values of surface reflectance of an input image using a principal component analysis of the given munsell chips. We estimate a CIE tristimulus values of an input image using the estimated .spectral distribution of illuminant and recover an image by scaling it regularity. From the experimental results, the proposed method was effective in estimating the image illumination

• Journal of Advanced Marine Engineering and Technology
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• v.30 no.1
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• pp.140-149
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• 2006

Characteristics of a laminar diffusion flame placed near wall in microgravity have been numerically analyzed in a two-dimension. The fuel for the flame is $C_2H_4$. The flame is initiated by imposing a high temperature ignition source. The flow field, temperature field, and flame shape in microgravity diffusion flame are detailed. Especially, effects of surrounding air velocity and fuel injection velocity on the microgravity diffusion flame have been discussed accounting for standoff distance. And, the effect of curvature rate has been also studied. The results showed that velocities in a diffusion flame were overshoot because of volumetric expansion and distribution of temperature showed regularity by free-buoyancy This means that the diffusion flame in microgravity is very stable, while the flame in normal gravity is not regular and unstable due to buoyancy. Standoff distance decreases with increase in surrounding air velocity and with decrease in fuel injection velocity. With increasing curvature rate, the position of reaction rate moves away the wall.