• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.847-858
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• 2015

Control strategy and corresponding parameters have significant impacts on the overall technical and economic characteristics of composite energy storage systems (CESS). A better control strategy and optimized control parameters can be used to improve the economic and technical characteristics of CESS, and determine the maximum power and stored energy capacity of CESS. A novel coordinated control strategy is proposed considering the coordination of various energy storage systems in CESS. To describe the degree of coordination, a new index, i.e. state of charge coordinated response margin of supercapacitor energy storage system, is presented. Based on the proposed control strategy and index, an optimization model was formulated to minimize the total equivalent cost in a given period for two purposes. The one is to obtain optimal control parameters of an existing CESS, and the other is to obtain the integrated optimal results of control parameters, maximum power and stored energy capacity for CESS in a given period. Case studies indicate that the developed index, control strategy and optimization model can be extensively applied to optimize the economic and technical characteristics of CESS. In addition, impacts of control parameters are discussed in detail.

• Journal of Biomedical Engineering Research
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• v.28 no.6
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• pp.750-755
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• 2007

The linear SEF (Spectral Edge Frequency) parameter and spectrum analysis method can not reflect the non-linear of EEG. This method can not contribute to acquire real time analysis and obtain a high confidence in the clinic due to low discrimination. To solve the problems, the development of a new index is carried out using the bispectrum analyzing the EEG including the non-linear characteristic. At the bispectrum analysis of the 2 dimension, the most significant's power spectrum density peaks appeared much at the specific area in awake and anesthesia state. Because many peaks are showed at the specific area in the frequency coordinate, these points are used to create the new index. Range of the index is 0-100. At the anesthesia, the index is 20-50 and at the awake, the index is 90-60. New index can discriminate the awake and anesthesia state.

• Geomechanics and Engineering
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• v.4 no.3
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• pp.219-227
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• 2012

Pavement management systems require systematic monitoring of pavement surfaces to determine preventive and corrective maintenance. The process involves the accumulation of large amounts of visual data, typically obtained from site visitation. The pavement surface condition is then correlated to a pavement distress index that is based on a scoring system previously established by state or federal agencies. The scoring system determines if the pavement section requires maintenance, overlay or reconstruction. One of the surface distresses forming part of the overall pavement distress index is the Alligator Crack Index (AC Index). The AC Index involves the visual evaluation of the crack severity of a section of a pavement as being low, medium, or high. This evaluation is then integrated into a formula in order to obtain the AC Index. In this study a quantification of the visual evaluation of the severity of alligator cracking is carried out using photographs and the fractal dimension concept from fractal theory. Pavements with low levels of cracking were found to have a fractal dimension equal to 1.051. Pavements with moderate levels of cracking had a fractal dimension equal to 1.1754. Pavements with high degrees of cracking had a fractal dimension that varied between 1.5037 (high) and 1.7111 (very high). Pavements with a level of cracking equal to 1.8976 represented pavements that disintegrated and developed potholes. Thus, the visual evaluation of the state of cracking of a pavement (the AC Index) could be enhanced with the use of the fractal dimension concept from fractal theory.

• Journal of Electrical Engineering and Technology
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• v.9 no.4
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• pp.1248-1257
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• 2014

Overhead transmission lines are crucial components in power transmission systems. Well-designed maintenance strategy for overhead lines is required for power utilities to minimize operating costs, while improving the reliability of the power system. This paper presents a maintenance priority index (MPI) of overhead lines for a reliability centered approach. Proposed maintenance strategy is composed of a state index and importance indices, taking into account a transmission condition and importance in system reliability, respectively. The state index is used to determine the condition of overhead lines. On the other hand, the proposed importance indices indicate their criticality analysis in transmission system, by using a load effect index (LEI) and failure effect index (FEI). The proposed maintenance method using the MPI has been tested on an IEEE 9-bus system, and a numerical result demonstrates that our strategy is more cost effective than traditional maintenance strategies.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.54 no.4
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• pp.287-295
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• 2018

The ichthyoplanktons were sampled to study distribution of the ichthyoplankton in coastal waters of Nanji-Island in August and November 2015 and January and May 2016. During the study, fish eggs of eight different species were collected. Engraulis japonicus was the most dominant species which accounted 44.80%. Sebastes schlegeli comprised 31.39% of the total larvae and juveniles. The diversity index of species per month of the collected juveniles at Nanji Island from 2015 to 2016 was 0.598-1.770 and the evenness index was 0.432-0.761. In case of dominance index was 0.619-0.897 against the evenness index. The analyzed species diversity index by the each station was 0.818-1.945 and the dominance index was 0.492-0.897 against the species diversity index. The months of August and May exhibited similar results. In addition, the community structure was very similar in state 2 and state 3.

• Journal of the Korean Geotechnical Society
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• v.27 no.9
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• pp.37-46
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• 2011

The compression index, which represents the compressibility of clay, is generally obtained from the consolidation test, or has been predicted by empirical correlations with soil properties. In this study, the results of consolidation tests on natural and reconstituted Busan and Inchon clays are analyzed to figure out the sedimentation state and its effect on empirical correlations. Results of analysis show that the void index of Busan clay is higher than SCL while the void index of Inchon clay is lower than SCL. By comparing prediction errors with ${\Delta}e_r$, which represents the sedimentation state of clay, it is shown that errors predicting the compressibility based on the liquid limit and plasticity index decrease as ${\Delta}e_r$ increases. Supplemented correlations predicting the compression index of Busan and Inchon clays are suggested using these relationships.

• Journal of Korean society of Dental Hygiene
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• v.11 no.4
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• pp.499-509
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• 2011

Objectives : The purpose of this study was to provide some information on down-to-earth oral health policy to improve the systemic health involving oral health and the quality of life in Korean adults. Methods : The third-year data of the 4th National Health and Nutrition Survey in 2009 were analyzed, and $x^2$(Chi-square) test was carried out to see whether there would be any gaps in subjective oral health status according to demographic characteristics, systemic health state, frequency of eating between meals and oral health behavior. In terms of the DMFT index, one-way ANOVA was utilized, and then Scheffe post-hoc analysis was conducted. Besides, multiple regression analysis was made to grasp the relationship of oral health behavior to subjective oral health state and the DMFT index. Results : The demographic characteristics, systemic health status and oral health behavior had a significant relationship to both of subjective oral health status and the DMFT index. As a result of analyzing the relationship of oral health behavior to subjective oral health state and the DMFT index, the subfactors of oral health behavior exerted a significant independent influence on subjective oral health status and the DMFT index. Conclusions : The findings of the study suggest that in order to promote the oral health of adults, preventive measures should be taken, and systematic oral health education should be provided. As there is an increase in the elderly population in Korea, the successful implementation of senior oral health plans and the development of oral health programs geared toward adults are both required.

• International Area Studies Review
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• v.15 no.3
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• pp.285-306
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• 2011

This paper analyzed the effects the regional competitiveness index on the characteristics of the regional growth. This study divides the regions in the US based on the static and dynamic standard of income for the characteristics of the regional growth. The results of the analysis are as follows. First some regions such as Alaska, Connecticut, Maryland, Massachusetts, Virginia, Washington and Wyoming have higher levels of SCI and both the rate of growth and per capita income than the national average. These are considered prosperous regions based on their high level of SCI. Second, in regards to the relation between the income level and regional competitiveness index for the regional growth, the variables such as human resource, science technology, business incubation, openness, safety and environmental policy are significant. Third, infrastructure, human resource, science technology and openness are the significant variables concerning the relation between the rate of income growth and regional competitiveness index for the regional growth.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.12
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• pp.152-160
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• 1999

The weld quality of $CO_2$ arc welding is closely related to the arc stability. As the characteristics of the arc are excessively complex and nonlinear, it is not easy to make the arc model as mathematical form and to control the arc state to be stabilized. This paper was aimed to estimate the arc stability and to control for stabilizing the arc state in short circuit metal transfer mode of $CO_2$ arc welding. For these purposes, the behaviors of arc stability was investigated at different welding conditions using Mita's arc stability index, and the fuzzy control algorithm which uses the arc stability index as control imput and the arc voltage as control output was developed. In the control of the arc stability, the experiments of two cases were performed; the case of setting an initial welding voltage arbitrarily, the case of the step change in workpiece shape. Obtained results were as follows; Mita's arc stability index was able to be estimated qualitatively in the case of using the inverter type welding power source and the control performance for stabilizing the arc status was excellent in the case of existing step change disturbance.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.5
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• pp.713-719
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• 2006

The effect of dietary iodine and selenium supplementation, alone or in combination, on peripheral blood lymphocyte function was determined in laying hens. Eight-hundred-and-sixty-four New-Loman laying hens were randomly allotted into 12 dietary treatments with different inclusion levels of iodine (0, 0.1 and 0.2 mg/kg), selenium (0, 0.05, 0.1 and 0.2 mg/kg) or their combinations for 24 weeks. The lipopolysaccharide (LPS) stimulation index, concanavalin A (ConA) stimulation index, peroxide enzyme activity and phagocytosis to neutral red particles were tested. There were significant differences in LPS stimulation index, ConA stimulation index, peroxide enzyme activity and phagocytosis to neutral red particles in different iodine or selenium supplementation levels (p<0.05). The highest iodine and selenium supplementation both resulted in highest LPS-/ConA-stimulation indices (p<0.05). However, when iodine was lower than 0.2 mg/kg, the additional effect of different levels of selenium did not always result in significant differences in these indices. The results indicated that iodine and selenium may affect immunity in laying hens and, when the iodine level in the laying hen is lower than 0.2 mg/kg, a selenium allowance higher than 0.1 mg/kg may be necessary to improve immunity.