• The Journal of the Acoustical Society of Korea
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• v.20 no.7
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• pp.83-88
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• 2001

In this paper, matched field processing algorithm robust to environmental mismatches in an ocean waveguide based on feature extraction is summarized. However, in applying this processor to localize a source there are two preliminary issues to be resolved. One is the number of eigenvectors to be extracted and the other is the number of environmental samples to be used. To determine these issues, the relation between the number of dominant modes propagating in a given ocean waveguide and that of eigenvectors to be extracted is analyzed. Then, the analysis results are confirmed by the subspace analysis. This analysis quantifies the similarity between the subspace spanned by the signal vectors and that spanned by the eigenvectors to be extracted. The error index is defined as a relative difference between the location estimated by the current processor and the real source location. It is identified that in the case of extracting the largest eigenvectors equal to the number of dominant modes in a given environment, the processor localizes the source successfully. From the numerical simulations, it is shown that use of at least 30 environmental samples guarantee stable performance of the proposed processor.

• Korean Journal of Remote Sensing
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• v.25 no.2
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• pp.175-184
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• 2009

This study attempts to analyze the difference among the variations of ecological distribution in Gobi desert and Manchuria through satellite based land cover classification. This was motivated by two well-known facts: 1) Gobi desert, which is an old source region, had been gradually expanded eastward; 2) Manchuria, which is located in east of Gobi desert, was observed as a new source region of yellow dust. An unsupervised classification called ISODATA clustering method was employed to detect the land cover change and to characterize the status of desertification and its expanding trends using NDVI (Normalized Difference Vegetation Index) derived from VEGETATION sensor onboard the SPOT satellite for 1999 and 2007. We analyzed NDVI annual variation pattern for every classes and divide into 5 level according to their vegetation's density level based on NDVI. As results, Gobi desert is showed positive variation: a decrease $78,066km^2$ in central Gobi desert and out skirts of Gobi desert (level-0) but Manchuria area is worse than previous time: an increase $25,744km^2$.

• Journal of Forest and Environmental Science
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• v.13 no.1
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• pp.1-27
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• 1997

This study was to survey the flora of resources vascular plants in the Experiment Forests of Kangwon National University. Resources vascular plants were composed of 98 families, 345 genera, 551 species, 2 subspecies, 88 varieties, 10 formae, and 2 hybrid, totaling 653 taxa. Among the investigated resources plants, Korean endemic plants and rare or endangered plants were distributed 20 taxa and 18 taxa, respectively. There were 27 taxa of Naturalized plants in this study area, which would have unpredictable influence on the natural ecosystem. The urbanized index(UI) of all over the investigated areas was about 12.4%. Useful resources plants were composed edible source(42.1%), medicinal source(33.8%), pasture source(28.8%), ornamental source(11.8%), timber source(5.2%), fiber source(1.4%), industrial source(1.1%). Vascular plants of unknown use were 140 taxa(21.4%).

• Journal of the Korean Society for Precision Engineering
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• v.26 no.5
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• pp.72-78
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• 2009

We propose the separation algorithm to simultaneously measure two-dimensional refractive index distribution and thickness profile of transparent samples using three wavelengths. The optical system was based on the Mach-zehnder interferometer with LD (Laser Diode)-based multi-wavelength sources. A LCR (Liquid Crystal Retarder) was used to obtain interference images at four phase states and then the optical phase of the object is calculated by four-bucket algorithm. Experimental results with a glass rod are provided at the different wavelengths of 635nm, 660nm and 675nm. The refractive indices of the sample are distributed with accuracy of less than 0.0005 and the thickness profile of sample was cylindrical type. This result demonstrates that it is possible to separate refractive index distribution and thickness profile of samples in two dimensions using the proposed algorithm.

• 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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.2C
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• pp.100-109
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• 2003

A differential index assignment scheme is proposed for the image encoding system in which a variable-length tree-structured vector quantizer is adopted. Each source vector is quantized into a terminal node of VLTSVQ and each terminal node is represented as a unique binary vector. The proposed index assignment scheme utilizes the correlation between interblocks of the image to increase the compression ratio with the image quality maintained. Simulation results show that the proposed scheme achieves a much higher compression ratio than the conventional one does and that the amount of the bit rate reduction of the proposed scheme becomes large as the correlation of the image becomes large. The proposed encoding scheme can be effectively used to encode R images whose pixel values we, in general, highly correlated with those of the neighbor pixels.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.6
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• pp.768-775
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• 2014

The purpose of this study was to analyze consumption patterns of health functional foods (HFF) according to climacteric symptoms. Subjects were 450 middle-aged women divided into four groups by Kupperman's index. This study collected all information by self-administrated questionnaires. Higher Kupperman's index was associated with higher Menopause-specific quality of life questionnaire (MENQOL) (P<0.001) and current smoker ratio (P<0.01) as well as lower monthly income (P<0.05). Exactly 28.4% of subjects showed negative responses to effectiveness of HFF. The average number of HFF intake per person was 2.01. The main reason for consumption of HFF was treatment or prevention of disease (33.6%). The information source for buying HFF was family or relatives (40.0%). The main types of HFF were vitamins (28.2%), omega-3 fatty acid (18.6%) and red ginseng (17.3%). The intake ratio of individual approval type (Cynanchum extract and Angeli extract) was significantly higher in subjects with high Kupperman's index (P<0.001). In conclusion, these results can be used as basic data that reflect middle-aged women's needs for HFF intake according to climacteric symptoms.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.5
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• pp.707-717
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• 2011

Replacement of old water distribution pipes for protecting water quality induced by pipe corrosion requires enormous budget. Even after the replacement, however, corrosion can occur again at any times and, therefore, inhibitive measure of the corrosion will be not only economical but needed to diminish the consumers' distrust on tap water quality. In 2008, National Environmental Research Institute did a survey on 8 major drinking water source and proposed to establish the Langelier Saturation Index(LI) as a corrosion index in Drinking Water Quality Criteria. Among the water industries of Korea, K-Water is the only one that set up the level of pH over 7.0 and LI above -1.5 on yearly average basis. However, no systematic regulation including LI to inhibit the corrosive tendency has been established yet. In this paper, LI values out of 31 drinking water treatment plants were analyzed and two-stage control of LI value as a measure of corrosive tendency of water is proposed. Primarily, water treatment facilities may operate the system at a target LI value below -1.5. Following the investigation on the effect caused by adjusting the LI value on water quality and corrosiveness, it will be desirable to improve LI value below -1.0 in the long run. In addition to the LI, supplemental use of Larson's modified ratio (LMR) which incorporates hydraulic detention time will be necessary. Several methods to prove the inhibitive effect of improving the LI value on water quality have been also suggested.

• Korean Journal of Veterinary Research
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• v.44 no.4
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• pp.649-653
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• 2004

To estimate the source of variance components for some hematological parameters and assess the utility of the conventional population-based reference interval, this study computed index of individuality for blood samples, which were from 13 dogs drawn once weekly for 4 consecutive weeks. Results were subjected to nested analysis of variance. For all parameters measured between-dog variations were greater than within-dog variation. Except for the parameters RBC and MCHC the index of individuality was <1.4. The low reliability coefficient and high index of individuality of ${\leq}0.8$ were found for the majority of hematological parameters. In practical term, the present study indicated that use of hemogram profiles alone in the evaluating clinical state of a single patient should be avoided because of their physiological or natural random variations, and that comparing a single measurement on the blood analytes from an individual dog to the conventional population-based reference range may be too insensitive to detect any significant changes in the blood components of that particular dog. A single measurement may not characterize an individual's average concentration of the parameters even shortterm period.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.7
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• pp.109-121
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• 2022

The study aims to examine the interaction of formal and informal institutions for strengthening economic development, particularly entrepreneurship growth. The research will also assess the impact of control variables on political index within the formal and informal markets. The research is quantitative, which analyses panel data of 6 years in 22 countries comprising middle and high-income countries with diversified and unique political, economic, and social systems. The findings suggested that reducing the entry regulation and promoting the social capital within the formal and informal institutions would grow formal and informal entrepreneurship and be a greater source for new venture creation. Moreover, the political index, a control variable, was found significant in the relationship of institutional mix with formal and informal entrepreneurship. Entry regulations in formal and informal institutions are a complex phenomenon in the entrepreneurship literature, moderated by the political development index as tested by the current study. The time horizon for this paper is much longer since it analyzes 6 years (2014-2019) of data on 22 developing and developed countries to see the entrepreneurial growth across multiple regions on different income levels, geographic conditions, and contrasting political and social systems.