• Journal of the military operations research society of Korea
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• v.25 no.2
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• pp.117-129
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• 1999

We consider a Location-Allocation Problem with the Cost of Land(LAPCL). LAPCL has extremely huge size of problem and complex characteristic of location and allocation problem. Heuristics and decomposition approaches on simple Location-Allocation Problem were well developed in last three decades. Currently, genetic algorithm(GA) is used widely at combinatorics and NLP fields. A lot of research show that GA has efficiency for finding good solution. Our main motive of this research is developing of a GA in LAPCL. We found that LAPCL could be reduced to trivial problem, if locations were given. In this case, we can calculate fitness function by simple technique. We propose fourth alternative genetic algorithm. Computational experiments are carried out to find a best algorithm.

• Journal of the Institute of Convergence Signal Processing
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• v.7 no.1
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• pp.38-44
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• 2006

The omnidirectional mobility of a mobile robot may lose significance in motion control, unless the isotropy characteristics of the mechanism is maintained well. This paper investigates the local and global isotropy of an omnidirectional mobile robot with three caster wheels. All possible actuations with different number and combination of rotating and steering joints are considered. First, the kinematic model based on velocity decomposition and the algebraic conditions for the local isotropy are obtained. Second, the geometric conditions for the local isotropy are derived and all isotropic configurations are fully identified. Third, the global isotropy index is examined to determine the optimal parameters in terms of actuation set, characteristic length, and steering link length.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.155-158
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• 2002

Eu-doped lead zirconium titanate $Pb_{1.1}(Zr_{0.3}Ti_{0.7})O_{3}$ thin films on the Pt/Ti/$SiO_2$/Si substrates prepared by a metalorganic decomposition (MOD) method. The effect on the structural and electrical properties of the films measured according to Eu content. Eu-doping altered significantly the dielectric and ferroelectric properties. The remanent polarization and coercive field decreased with increasing the concentration of Eu content. The dielectric constant and dielectric loss of the film decreased with increasing Eu contents. The 3 mol% of Eu-doped PZT thin film showed large remanent polarization and the fatigue characteristic of the film did not change up to $10^9$ switching cycles.

• Korean Journal of Computational Design and Engineering
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• v.12 no.5
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• pp.354-365
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• 2007

We present novel methods to generate a sequence of shapes that represents the pattern of morphological development or transformation of Bezier curves. The presented methods utilize the intrinsic geometric structures of a Bezier curve that are derived from rib and fan decomposition (RFD). Morphological development based on RFD shows a characteristic pattern of structural growth of a Bezier curve, which is the direct consequence of development path defined by fans. Morphological transformation based RFD utilizes development patterns of source and target curves to mimic the theory of evolutionary developmental biology: although the source and target curves are quite different in shapes, we can easily find similarities in their younger shapes, which makes it easier to set up feature correspondences for blending them. We also show that further controls on base transformation for intensity of feature blending, and extrapolation can compensate the immaturity of blended curves. We demonstrate the experimental results where transformation patterns are smoother and have unique geometric style that cannot be generated using conventional methods based on multi-linear blending.

• IEIE Transactions on Smart Processing and Computing
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• v.4 no.2
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• pp.103-109
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• 2015

In this paper, a novel method for the classification of term and preterm birth is proposed based on time-frequency analysis of electrohysterogram (EHG) using multivariate empirical mode decomposition (MEMD). EHG is a promising study for preterm birth prediction, because it is low-cost and accurate compared to other preterm birth prediction methods, such as tocodynamometry (TOCO). Previous studies on preterm birth prediction applied prefilterings based on Fourier analysis of an EHG, followed by feature extraction and classification, even though Fourier analysis is suboptimal to biomedical signals, such as EHG, because of its nonlinearity and nonstationarity. Therefore, the proposed method applies prefiltering based on MEMD instead of Fourier-based prefilters before extracting the sample entropy feature and classifying the term and preterm birth groups. For the evaluation, the Physionet term-preterm EHG database was used where the proposed method and Fourier prefiltering-based method were adopted for comparative study. The result showed that the area under curve (AUC) of the receiver operating characteristic (ROC) was increased by 0.0351 when MEMD was used instead of the Fourier-based prefilter.

• Journal of the Korea Institute of Military Science and Technology
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• v.8 no.1 s.20
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• pp.14-24
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• 2005

A propellant mainly consisting of nitric ester including nitrocellulose, nitroglycerine and nitroguanidine is characteristic of being decomposed naturally. And this phenomenon is known as being affected mostly by its storing temperature. In this research, the effect of storing temperature on self life has been studied by measuring the contained quantity of residual stabilizer of propellant KM30A1, ignition powder and combustible cartridge case, which are parts of 155MM propelling charge K676 and K677; the method for the measurement is acceleration aging test, and decomposition reaction equation and Berthlot Equation were used for the calculation. The result of this research shows that propellant KM30A1, ignition powder, combustible cartridge case in order of decreasing self life, and the self life decreases to 1/3 as the temperature increases by $10^{\circ}C$.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.3
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• pp.336-341
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• 2013

Power converter plays a very important role in switched reluctance motor (SRM) systems, and it is also the easiest one to experience failures. Power converter faults will cause the motor to run in non equilibrium states, and a long time fault operation will lead to motor and other modules damaged, and make the system completely lose working stability. This paper uses an asymmetric bridge converter as the research object with three-phase SRM, employs the wavelet packet decomposition for the phase currents. It analyzes and studies the short circuit fault condition of IGBT, uses an energy discrete degree of the wavelet packet nodes as the fault characteristic, and conducts the corresponding experimental and simulation analysis to verify the effectiveness and practicality of the proposed method.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.2
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• pp.167-174
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• 1996

In this paper, a fault location algorithm is presented, which uses novel signal processing techniques and takes a new paradigm to overcome some drawbacks of the conventional methods. This new method for fault location on electric power transmission lines uses only one-terminal fault signals. The main feature of the method is hat it uses the high frequency components in fault signal and considers the influence of the source network by using a traveling wave propagation characteristics. As a result, we can develop a high speed, good accuracy fault locator.

• Journal of Korean Society of Rural Planning
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• v.22 no.2
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• pp.109-119
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• 2016

Most of countries are trying to increase the supply of renewable energy as the substitute of the fossil energy for reducing greenhouse gas emissions. However, renewable energy sources account for only about 3.86% of the total Korea primary energy supply. To increase the rate of renewable energy in Korea's energy consumption, various policies for expanding the use of renewable energy should be applied. Also these policies should be consider renewable energy resources distribution and regional inequality. In this study, the potentials of photovoltaic, wind power and bioenergy from rice straw, livestock waste and food waste are calculated and the distribution characteristic and regional inequalities are analyzed using Gini's coefficient and Gini decomposition method. As the results, technical potentials of photovoltaic and wind power of city region(Gu) has more potential rate than theoretical potentials. Livestock waste has the most unequal distribution (Gini's coefficient: 0.617) among renewable resources.

• Analytical Science and Technology
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• v.24 no.6
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• pp.493-502
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• 2011

The catalyst works for visible-light region was characterized. Toluene, xylene, MEK and ammonia were used as reactants. The decomposition efficiency was compared between visible-light photocatalyst and UV-light one. UV-photocatalyst can be activated with UV-light wave length of 280~360 nm. However, visible-light photocatalyst can be activated with visible wave length of 400~750 nm. This result was found by using UV-Vis absorbance. A lot of materials were doped to visible light photocatalyst in order to increase its performance. Platinum was added to visible light photocatalyst with manganese in order to increase performance of the visible light photocatalyst. MTMS (Methyl tri methoxy silane) was used as a binder. Contact angle was analyzed varying with amount of binder. Contact angle was increased with increasing the amount of MTMS. As a result, the hydrophilic property of photocatalyst with MTMS binder was decreased due to its hydrophobic one. And Mn-$TiO_2$ catalyst had an excellent anti-bacterial property.