• Title/Summary/Keyword: L Index

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Comparison of Remote Sensing and Crop Growth Models for Estimating Within-Field LAI Variability

  • Hong, Suk-Young;Sudduth, Kenneth-A.;Kitchen, Newell-R.;Fraisse, Clyde-W.;Palm, Harlan-L.;Wiebold, William-J.
    • Korean Journal of Remote Sensing
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    • v.20 no.3
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    • pp.175-188
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    • 2004
  • The objectives of this study were to estimate leaf area index (LAI) as a function of image-derived vegetation indices, and to compare measured and estimated LAI to the results of crop model simulation. Soil moisture, crop phenology, and LAI data were obtained several times during the 2001 growing season at monitoring sites established in two central Missouri experimental fields, one planted to com (Zea mays L.) and the other planted to soybean (Glycine max L.). Hyper- and multi-spectral images at varying spatial. and spectral resolutions were acquired from both airborne and satellite platforms, and data were extracted to calculate standard vegetative indices (normalized difference vegetative index, NDVI; ratio vegetative index, RVI; and soil-adjusted vegetative index, SAVI). When comparing these three indices, regressions for measured LAI were of similar quality $(r^2$ =0.59 to 0.61 for com; $r^2$ =0.66 to 0.68 for soybean) in this single-year dataset. CERES(Crop Environment Resource Synthesis)-Maize and CROPGRO-Soybean models were calibrated to measured soil moisture and yield data and used to simulate LAI over the growing season. The CERES-Maize model over-predicted LAI at all corn monitoring sites. Simulated LAI from CROPGRO-Soybean was similar to observed and image-estimated LA! for most soybean monitoring sites. These results suggest crop growth model predictions might be improved by incorporating image-estimated LAI. Greater improvements might be expected with com than with soybean.

Design of an Efficient Parallel High-Dimensional Index Structure (효율적인 병렬 고차원 색인구조 설계)

  • Park, Chun-Seo;Song, Seok-Il;Sin, Jae-Ryong;Yu, Jae-Su
    • Journal of KIISE:Databases
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    • v.29 no.1
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    • pp.58-71
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    • 2002
  • Generally, multi-dimensional data such as image and spatial data require large amount of storage space. There is a limit to store and manage those large amount of data in single workstation. If we manage the data on parallel computing environment which is being actively researched these days, we can get highly improved performance. In this paper, we propose a parallel high-dimensional index structure that exploits the parallelism of the parallel computing environment. The proposed index structure is nP(processor)-n$\times$mD(disk) architecture which is the hybrid type of nP-nD and lP-nD. Its node structure increases fan-out and reduces the height of a index tree. Also, A range search algorithm that maximizes I/O parallelism is devised, and it is applied to K-nearest neighbor queries. Through various experiments, it is shown that the proposed method outperforms other parallel index structures.

A Study on Vegetation Index for Zoning of Natural Ecosystem on Baekdudaegan -From Namdeogyusan to Sosagogae- (백두대간 자연생태계의 지역구분을 위한 식생지수에 관한 연구 -남덕유산 -소사고개 구간-)

  • 김갑태;엄태원
    • Korean Journal of Environment and Ecology
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    • v.18 no.2
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    • pp.158-166
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    • 2004
  • For the zoning of natural ecosystem, Vegetation Index is calculated from the vegetation data surveyed on Baekdudaegan (from Namdeogyusan to Sosagogae). Five factors-biodiversity, conservation value of the stand, environmental quality, longevity of the stand, site productivity- are considered in the calculation of Vegetation Index. Vegetation Index might be a useful zoning tool for management of Baekdudaegan. For Vegetation Index I, 8 sample plots 12.l% of total 66 sample plots are belong to core area, 21 sample plots 31.8% and 37 sample plots 56.l% are belong to buffer zone and transition area, respectively. For Vegetation Index II, 37 sample plots 41.9% of total 60 sample plots are belong to core area, 19 sample plots 28.8% and 19 sample plots 28.8% are belong to buffer zone and transition area, respectively.

CIRCULAR UNITS IN A BICYCLIC FUNCTION FIELD

  • Ahn, Jaehyun;Jung, Hwanyup
    • Journal of the Chungcheong Mathematical Society
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    • v.21 no.1
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    • pp.61-69
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    • 2008
  • For a real subextension of some cyclotomic function field with a non-cyclic Galois group order $l^2$, l being a prime different from the characteristic of function field, we compute the index of the Sinnott group of circular units.

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A Seasonal Characteristic of Marine Environment and Fish Assemblage in the Coastal waters Jeju Island, Korea from 2012 to 2013 (제주도 연안 해양환경과 어류군집의 계절별 특성 (2012~2013년))

  • Ko, Jun-Cheol;Kim, Bo-Yeon;Kim, Maeng-Jin;Park, Sung-Eun;Kim, Jong-Bin;Cho, Hyung-Kee
    • Journal of Fisheries and Marine Sciences Education
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    • v.27 no.2
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    • pp.319-344
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    • 2015
  • A seasonal characteristic of marine environment and fish assemblages in the coastal waters of Jeju Island were determined using samples collected by a trammel net in from 2012 to 2013. Annual mean temperature and salinity were $18.8^{\circ}C$, 33.7psu (2012) and $18.8^{\circ}C$, 33.8psu (2013) which shows stable water mass. nutrient concentrations represent that dissolved inorganic nitrogen (DIN) ranged from 0.030 to 0.217mg/L, dissolved inorganic phosphorus (DIP) from 0.002 to 0.010mg/L, and silicate ($SiO_2$) from 0.096 to 0.292mg/L. Chlorophyll a concentrations of phytoplankton ranged from 0.905 to $1.125{\mu}g/L$ were appeared the highest in summer and the lowest in winter. Suspended Solid(SS) concentrations ranged from 1.200 to 2.100mg/L (mean, 1.634mg/L) were appeared the highest in autumn and the lowest in spring. During the survey period, a total of 83 species (48 families and 12 orders) of fishes were identified, Perciformes and Scorpaeniformes accounted for 63.9% of the total number. The number of species was higher in summer than in winter, showing a peak in summer at 57 species and a low in winter at 47 species. The number of individuals and the biomass peaked in summer at 694 individuals and 151.9kg, and were the lowest in autumn at 466 individuals and 106.5kg. The diversity index, evenness index and richness index were appeared 2.92~3.14, 0.75~0.83 and 7.06~8.56 at each stations. the dominance index were appeared highest in spring and summer, were appeared the lowest in winter and autumn. The Filefish (Stephanolepis cirrhifer), Bluestriped angelfish (Chaetodontoplus septentrionalis), Marbled rockfish (Sebastiscus marmoratus), Rabbit fish (Siganus fuscescens), Blackfin sweeper (Pempheris japonica) were dominant species, which occurred abundantly during the entire survey period. The subtropical fishes were identified total of 41 species (49.4%) and the number of species was higher in summer at 29 (50.9%) species and a low in winter at 20 (42.6%) species. The dominant species of subtropical fishes were appeared Bluestriped angelfish, Blackfin sweeper, Rabbit fish, Scarbreast tuskfish (Choerodon azurio), Ballonfish (Diodon holocanthus), Flagfish (Goniistius zonatus), Blue-spotted boxfish (Ostracion immaculatus) in study sites. The subtropical fishes of species, individual and biomass showed significant correlation with environmental factors (Chlorophyll a, DIN, DIP, $SiO_2$) in almost all sampling sites.

Power extraction efficiency and lasing wavelength distribution of index-coupled DEB lasers above-threshold for various facet reflectivity combinations (문턱 전류 이상에서 양 단면 반사율 조합에 따른 index-coupled DFB 레이저의 파워 추출 효율과 발진 파장 분포)

  • 김상택;김부균
    • Korean Journal of Optics and Photonics
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    • v.14 no.4
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    • pp.413-422
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    • 2003
  • We have calculated the power extraction efficiency and the lasing wavelength distribution of index-coupled DFB lasers at threshold for various kL and facet reflectivity combinations, and compared with those above-threshold. The power extraction efficiency increases as the asymmetry of the facet reflectivities increases. The power extraction efficiency above-threshold is slightly larger than that at threshold. Since the relative photon density around the center region increases as kL increases, the power extraction efficiency decreases. The uniformity of the distribution of lasing wavelength over the stop band increases due to the relief of mode degeneracy as the asymmetry of the facet reflectivities increases. In the case of AR-HR combination, the lasing wavelength distributions at threshold are similar to those above-threshold. However, in the case of AR-AR combination, the lasing wavelength at threshold is concentrated on both edges of the stop band, while it is concentrated only on the longer wavelength edge above-threshold. As kL increases, the range of the lasing wavelength distribution increases due to the increase of the stop band. The effect of AR reflectivity on the power extraction and the lasing wavelength distribution is very weak.

Health-related quality of life in elderly patients with diabetes mellitus according to age: based on Korea National Health and Nutrition Examination Survey (노인 당뇨병 인지자의 연령에 따른 삶의 질 수준 분석: 국민건강영양조사를 이용하여)

  • Kang, Yeji;Park, Kyong
    • Journal of Nutrition and Health
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    • v.53 no.2
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    • pp.129-140
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    • 2020
  • Purpose: Although the importance of life satisfaction in patients with chronic diseases has been emphasized, limited studies have been performed on the health-related quality of life (HRQoL) among elderly patients with chronic diseases. This study examined the HRQoL among Korean patients with diabetes aged 65 years or older. Methods: This study used data from the Korea National Health and Nutrition Examination Survey 2008-2016. The analysis included data of 2,353 elderly patients with diabetes aged 65 years or older who were aware that they had type 2 diabetes. Each participant was categorized into one of three age groups (65-69 years, 70-74 years, and ≥ 75 years). The EuroQol-5 Dimensions (EQ-5D) scale was computed to estimate the HRQoL. Multivariate linear regression analysis was used to compare the demographic characteristics, lifestyle characteristics, nutrient intake, and EQ-5D scores between the age groups. Results: The intake levels of most nutrients were similar in the three age groups, but the total energy intake levels were significantly lower, and the sodium intake levels were significantly higher in the older age groups (p < 0.001). In addition, all items of the EQ-5D index, except for anxiety/depression, tended to decrease with age. In particular, the oldest age group (≥ 75 years) showed significantly lower levels on most items and the EQ-5D index than those in the other age groups (p < 0.001). Conclusion: Elderly patients with type 2 diabetes may have low levels of life satisfaction, which worsens with increasing age. Therefore, it is important to develop and manage personalized guidelines and medical systems so that elderly patients have a higher quality of life for the remainder of their lives. The results of this study are expected to be used as basic data for the systematic management of diabetes in elderly Korean patients.

Geographical distribution of vectors and sero-strains of tsutsugamushi disease at mid-south inland of Korea (한반도 중남부 내륙지방에서의 쭈쭈가무시병 혈청형과 매개종의 지리적 분포상)

  • 이한일;이인용
    • Parasites, Hosts and Diseases
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    • v.35 no.3
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    • pp.171-180
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    • 1997
  • Studies on geographical distributions and relative population densities of the vector mites of tsutsugamushi disease were carried out in October 1996 at 12 locations of the mid south inland of the Korean peninsula, where chigger mites have been never studied. Of 177 field rodents and insectivores collected. 154 (87.0%) were Apodemus ngrarius. Total 25,707 chigger mites were collected and 14 species were identified. of which Leptotrombidium pnllidum was predominant (79.8%) and L. palpate the next (8.9%) . L. pallidum, the vector species, was widely distributed in all study areas, showing the highest density at Cho-o 2-dong, Sangju-si (chigger index 201.8), and the lowest at Tanwol-dong. Chungiu-si (chigger index 40.7) . The other vector species, L. scutellare was found only at the southern part of the study area such as Yobae and Mipyong, Kumrung gun and Vnsu , Kimchon-si. The northernmost areas of the L. scutellcre distribution were coincided with the areas where actual mean air temperature is above 10.0%. Among 157 A. ograrius sera tested, 48.3% was Karp, 1.7% william and 3.3% Kuroki. The rest of the sera were not able to determine the sexto-type because of the cross antigen-antibody reactions among the tested sero-types.

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The Study on Application of Regional Frequency Analysis using Kernel Density Function (핵밀도 함수를 이용한 지역빈도해석의 적용에 관한 연구)

  • Oh, Tae-Suk;Kim, Jong-Suk;Moon, Young-Il;Yoo, Seung-Yeon
    • Journal of Korea Water Resources Association
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    • v.39 no.10 s.171
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    • pp.891-904
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    • 2006
  • The estimation of the probability precipitation is essential for the design of hydrologic projects. The techniques to calculate the probability precipitation can be determined by the point frequency analysis and the regional frequency analysis. The regional frequency analysis includes index-flood technique and L-moment technique. In the regional frequency analysis, even if the rainfall data passed homogeneity, suitable distributions can be different at each point. However, the regional frequency analysis can supplement the lacking precipitation data. Therefore, the regional frequency analysis has weaknesses compared to parametric point frequency analysis because of suppositions about probability distributions. Therefore, this paper applies kernel density function to precipitation data so that homogeneity is defined. In this paper, The data from 16 rainfall observatories were collected and managed by the Korea Meteorological Administration to achieve the point frequency analysis and the regional frequency analysis. The point frequency analysis applies parametric technique and nonparametric technique, and the regional frequency analysis applies index-flood techniques and L-moment techniques. Also, the probability precipitation was calculated by the regional frequency analysis using variable kernel density function.

The Effect of Antifat Diets with β-Cyclodextrin on the Weight Loss in Obese Korean Women (비만 여성에서 베타-사이클로덱스트린 함유 다이어트 식품의 체중 감소 효과)

  • 박병성
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.5
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    • pp.832-838
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    • 2004
  • This study investigated the effects of an antifat diet with $\beta$-cyclodextrin on the reduction of body weight, obesity index, body mass index, body fat mass, body circumferences and plasma lipid levels in obese Korean women. After maintaining an antifat diet for 45 days, there were significant reductions in body weight by 4 kg, obesity index by 5%, body mass index by 1 kg/$m^2$ and body fat mass by 7% as absolute values (p<0.05). When expressed as percentages of the decrease, these reductions remained significant at 4%, 13%, 4% and 20%, respectively (p<0.05). In addition, after maintaining this antifat diet for 45 days, there were also significant reductions in arm, waist, hip and thigh circumferences by 3 cm as absolute values when compared to before intake of antifat diet, and these reductions remained significant at 8%, 3.4%, 3% and 5%, respectively (p<0.05) as percentages of the decrease. Furthermore, this antifat diet significantly reduced triacylglyceride by 103 mg/dL, total cholesterol by 50 mg/dL and LDL-C by 50 mg/dL respectively (p<0.05). Thus, the present results demonstrate that $\beta$-cyclodextrin may have benefit as a novel food resource for diets to prevent obesity and control overweight in adult women.