• Spatial Information Research
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• v.20 no.4
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• pp.47-55
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• 2012

Normalized Difference Vegetation Index (NDVI) has been used to measure and monitor plant growth, vegetation cover, and biomass from multispectral satellite data. It is also a valuable index in forest applications, providing forest resource information. In this research, an approach for monitoring forest change using MODIS NDVI time series data is explored. NDVI difference-based approaches for a specific point in time have possible accuracy problems and are lacking in monitoring long-term forest cover change. It means that a multi-time NDVI pattern change needs to be considered. In this study, an efficient methodology to consider long-term NDVI pattern is suggested using a harmonic model. The suggested method reconstructs MODIS NDVI time series data through application of the harmonic model, which corrects missing and erroneous data. Then NDVI pattern is analyzed based on estimated values of the harmonic model. The suggested method was applied to 49 NDVI time series data from Aug. 21, 2009 to Sep. 6, 2011 and its usefulness was shown through an experiment.

• Korean Journal of Community Nutrition
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• v.4 no.2
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• pp.157-165
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• 1999

This study was conducted to identify the determinants of regional body fat distribution of obesity(upper body obesity and lower body obesity) for adolescents. The macronutrient consumption pattern utilized the most important variables to test for potential determinants. A total of 726 adolescents living in rural areas in Korea had been observed for four years from 1992 to 1996 about their diet, sexual maturation, serum components and physical growth. The study design was similar to that of a case control study. Logistic regression analysis were used as an analytical method to identify the determinants of upper body obesity and lower body obesity. Odd ratios were estimated from the regression to identify the determinants of upper body obesity and lower body obesity. Odd ratios were estimated from the regression to identify the risk factors. Fat consumption pattern was the most frequent one among the three macronutrient consumption pattern of carbohydrate, fat and protein. Prevalence of obesity for the subjects was 9.5%. Prevalence of upper body obesity was higher in malestudents than in female students. On the other had, prevalence of lower body obesity was higher in females. The results of the logicstic regression analysis showed that the risk factor for upper body obesity was sexual maturity rather than dietary factors. None of the factors included in the analysis for lower body obesity appear to be the risk factor. The result may suggest that to develop a determinant model for obesity of adolescents, the model should include a wider range of variables other than diet, sexual maturity and changes in blood serum.

• International Journal of Computer Science & Network Security
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• v.21 no.8
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• pp.281-287
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• 2021

Bioinformatics is formed with a blend of biology and informatics technologies and it employs the statistical methods and approaches for attending the concerning issues in the domains of nutrition, medical research and towards reviewing the living environment. The ceaseless growth of DNA sequencing technologies has resulted in the production of voluminous genomic data especially the DNA sequences thus calling out for increased storage and bandwidth. As of now, the bioinformatics confronts the major hurdle of management, interpretation and accurately preserving of this hefty information. Compression tends to be a beacon of hope towards resolving the aforementioned issues. Keeping the storage efficiently, a methodology has been recommended which for attending the same. In addition, there is introduction of a competent algorithm that aids in exact matching of small pattern. The DNA representation sequence is then implemented subsequently for determining 2 bases to 6 bases matching with the remaining input sequence. This process involves transforming of DNA sequence into an ASCII symbols in the first level and compress by using LZ77 compression method in the second level and after that form the grid variables with size 3 to hold the 100 characters. In the third level of compression, the compressed output is in the grid variables. Hence, the proposed algorithm S_Pattern DNA gives an average better compression ratio of 93% when compared to the existing compression algorithms for the datasets from the UCI repository.

• Journal of Welding and Joining
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• v.16 no.5
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• pp.56-66
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• 1998

During solidification or welding of alloys, the solute redistribution brings out microsegregation. The microsegregation causes the formation of non-equilibrium second phases, shrinkage and porosity degrading mechanical/chemical properties Therefore, it has been required to predict microsegregation quantitatively. To predict the degree of microsegregation, more exact and appropriate computer simulation technique has been actively used during last two decades. To predict the degree of microsegregation in weld metal, an advanced two dimensional model was suggested. In the new model, both primary and secondary arm regions were defined for the analysis region. The growth in the primary arm regina was assumed to be a planar for effective calculation. Especially, for the growth of a secondary arm, a simple and effective mathematical function was established to show the growing pattern, the solute diffusion in the solid phase was calculated by finite difference method (FDM). The solid-liquid interface movement was considered to be in local equilibrium state. The experiments for welding of 310S stainless steel were carried out in order to examined the reasonability and feasibility of this model. The concentration profiles of the solute predicted by this model were compared with those obtained from experimental works.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.13 no.2
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• pp.93-97
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• 2003

The crystallization behavior of amorphous silicon is affected by direction and intensity of electric field in FALC（Field-Aided Lateral Crystallization). Electric field was calculated in a simplified model using conductivity data of Mo, a-Si, $SiO_2$and boundary conditions for electric potential at the electrodes. The magnitude of electric field intensity in each corner of cathode was much larger than that in the center of patterns, and the electric field direction was 50~60 degree outside to cathode. And electric field intensity at a relatively small pattern was larger than that of a large pattern.

• International Journal of Fluid Machinery and Systems
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• v.2 no.3
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• pp.215-222
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• 2009

Jets issuing through small holes in a wall into a freestream has proven effective in the control of flow separation. This technique is known as the vortex generator jet (VGJs) method. If a precursor signal of separation is found, the separation control system using VGJs can be operated just before the onset of separation and the flow field with no separation is always attained. In this study, we measured the flow field and the wall static pressure in a two-dimensional diffuser to find a precursor signal of flow separation. The streamwise velocity measurements were carried out in the separated shear layer and spectral analysis was applied to the velocity fluctuations at some angles with respect to the diffuser. The pattern of peaks in the spectral analysis changes as the divergence angle increases over the angle of which the whole separation occurs. This change in the spectral pattern is related to the enhancement of the growth of shear layer vortices and appears just before the onset of separation. Therefore, the growth of shear layer vortices can be regarded as a precursor signal to flow separation.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.7 no.2
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• pp.197-206
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• 1997

A SiC epilayer on the 6H-SiC crystal substrate was grown by chemical vapor deposition (CVD). The crystal structure of the SiC epilayer was investigated by using the X-ray diffraction patterns and the Roman scattering spectroscopy. The SiC epilayer on the 6H-SiC substrate was grown to be homoepilayer by CVD. In order to distinguish a certain SiC polytype mixed in the SiC crystal grown by the modified Lely method, we have calculated the X-ray diffraction intensities and Brags angles of the typical SiC crystal powders. By comparing the measured X-ray diffraction pattern with the calculated ones, it was identified that the SiC crystal grown by the modified Lely method was the 6H-SiC crystal mixed some 15R-SiC.

• BMB Reports
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• v.29 no.3
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• pp.221-224
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• 1996

To examine the growth-phase dependent control of Escherichia coli rnpB gene we used a combination of Northern analysis for RNA determination and Southern analysis for plasmid DNA determination. The relative amounts of metabolically unstable transcript derived from the internally deleted rnpB gene harbored on a multicopy plasmid as well as the relative plasmid contents were measured by Northern analysis and Southern analysis, respectively, of total nucleic acids from E coli cells containing the plasmid. The relative transcription activity of the rnB was represented by a ratio of the relative amount of the transcript to that of the plasmid DNA during bacterial growth. The rnpB transcription increased rapidly with time during exponential growth, but started to decrease before the transition period of an exponential growing cell culture into the stationary phase. Although the expression pattern was similar to the changes of ${\beta}-galactosidase$ activity expressed from the lysogenic strain carrying the chromosomal rnpB-lacZ fusion which were shown in a previous work, the present data appears to represent a more actual growth-phase control of the rnpB transcription than the previous data by the ${\beta}-galactosidase$ assay. In addition the present method described for a direct analysis of both RNA and plasmid DNA provides a rapid and efficient method that can applied to an examination of transcription control by using a multicopy plasmid.

• Journal of the Korean Vacuum Society
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• v.1 no.3
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• pp.353-359
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• 1992

본 연구에서는 HWE 방법에 의하여 GaAs(100) 기판위에 입방정의 단결정 박막을 성장하였다. 성장된 CdS 단결정 박막의 결정구조와 방향을 ECP(electron channeling pattern)로 결정하였다. CdS 박막의 (400)면이 기판과 평행하게 성장됨을 알았다. CdS 박 막의 photoluminescence를 20K에서 측정하였는데, free exception, bound exception 및 donor-acceptor pair에 의한 발광이 관측되었다.

• Journal of the Korean Ceramic Society
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• v.23 no.1
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• pp.21-26
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• 1986

By the floating zone method with infrared radiation convergence type heater homogeneously $Cr^{3+}$ doped alu-mina single crystal was obtained. And sizx {1010} facets appeared at the surface of [0001] grown crystals. $ZrO_2$ and $HfO_2$ precipitated as secondary phase and were not doped in the crystals. We found that the dist-ribution of the secondary phase which was mainly located at the surface and the peripheral region was closely related to the flow pattern of melt zone.