• Title/Summary/Keyword: Synthetic Spectrum

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Validation of Sea Surface Wind Estimated from KOMPSAT-5 Backscattering Coefficient Data (KOMPSAT-5 후방산란계수 자료로 산출된 해상풍 검증)

  • Jang, Jae-Cheol;Park, Kyung-Ae;Yang, Dochul
    • Korean Journal of Remote Sensing
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    • v.34 no.6_3
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    • pp.1383-1398
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    • 2018
  • Sea surface wind is one of the most fundamental variables for understanding diverse marine phenomena. Although scatterometers have produced global wind field data since the early 1990's, the data has been used limitedly in oceanic applications due to it slow spatial resolution, especially at coastal regions. Synthetic Aperture Radar (SAR) is capable to produce high resolution wind field data. KOMPSAT-5 is the first Korean satellite equipped with X-band SAR instrument and is able to retrieve the sea surface wind. This study presents the validation results of sea surface wind derived from the KOMPSAT-5 backscattering coefficient data for the first time. We collected 18 KOMPSAT-5 ES mode data to produce a matchup database collocated with buoy stations. In order to calculate the accurate wind speed, we preprocessed the SAR data, including land masking, speckle noise reduction, and ship detection, and converted the in-situ wind to 10-m neutral wind as reference wind data using Liu-Katsaros-Businger (LKB) model. The sea surface winds based on XMOD2 show root-mean-square errors of about $2.41-2.74m\;s^{-1}$ depending on backscattering coefficient conversion equations. In-depth analyses on the wind speed errors derived from KOMPSAT-5 backscattering coefficient data reveal the existence of diverse potential error factors such as image quality related to range ambiguity, discrete and discontinuous distribution of incidence angle, change in marine atmospheric environment, impacts on atmospheric gravity waves, ocean wave spectrum, and internal wave.

An Integrated Approach in the Pest Management in Sericulture

  • Singh, R.N.;Saratchandra, Beera
    • International Journal of Industrial Entomology and Biomaterials
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    • v.5 no.2
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    • pp.141-151
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    • 2002
  • The success of sericulture industry in India is mainly attributed to the well-planned annual sericultural activity and the systematic implementation of pest preventive and control measures. The insect spectrum of silkworm and its food plants is complex and plays a major role in limiting the production of silk. Insects cause extensive damage to plant whereas predators and parasites either kill the silkworm larvae or force them to spin flimsy cocoons. Unilateral control measure against this pest is mainly based on the use of synthetic organic insecticides. Though these approaches initially paid rich dividends, the undesirable consequences soon surfaced. Insecticide induced resurgence of gall midges, leafhopper, leaf roller, secondary pest out breaks and development of pest biotypes has led to realization of Integrated Pest Management in sericulture. Various components of IPM, viz. Host plant resistance, cultural practices, biological control, chemical control and integrating them at various technological levels have been studied. Sources of host plant resistance have been identified for some of the major insect pests. High yielding mulberry variety has been propagated and their resistances towards major pests have been recorded. Cultural practices like pruning, pollarding, judicious use of nitrogen, optimum spacing and weed management have preyed to be the powerful tools in containing pests. Natural control over the pest population build- up exerted by the wide range of parasitoids, predators and pathogens has been well documented with identification of natural enemies and studies on their potential. Augmentation, through inoculation or inundative releases of parasitic arthropods, is the most direct way of increasing the numbers of these beneficials in sericulture.

Preparation and Characterization of Cy3 Dye with Various Counter Cations (다양한 상대 양이온을 갖는 Cy3 염료의 제조 및 특성 연구)

  • Lee, Sang Dong;Hyun, Dong Kyoun;Jeong, Yeon Tae
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.28 no.5
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    • pp.314-319
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    • 2015
  • In this research, we focused on the development of cy3 dye with high thermal stability and good solubility for LCD color filter. Cy3 dyes were prepared through the synthetic procedure of two steps. The synthesized cy3 dyes were characterized by using NMR, FT-IR, UV/Vis spectroscopy, and TGA. These cy3 dyes showed maximum absorption wave length (${\lambda}_{max}$) in the range of 549~555 nm in UV/Vis spectrum. And we confirmed that solubility characteristics and thermal stability of cy3 dyes were dependent on the structure of counter cation. Cy3 dyes with methyl counter cation and ethyl counter cation have good solubility in organic solvents such as chloroform, ethanol, and PGME. Moreover, Cy3 dye with ethyl counter cation gave excellent thermal stability in TGA thermograms. And Cy3 dye with ethyl counter cation showed good result in photoresist film test.

In vitro anthelmintic evaluation of common Indian Ayurvedic anthelmintic drugs: Krimimudgar Ras, Kriminol and Vidangasava against intestinal helminths

  • Chen, Risa Parkordor;Yadav, Arun K.
    • CELLMED
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    • v.8 no.3
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    • pp.15.1-15.5
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    • 2018
  • Helminthiasis is one of the most common worm diseases which causes a range of adverse health problems in humans. Ayurveda is one of the most prominent and ancient systems of traditional medicines in India. Most Ayurvedic drugs used against intestinal helminths have been developed by traditional wisdom and therefore lack a proper validation through controlled studies. The aim of the present study was to scientifically validate the in vitro efficacy of three common Indian Ayurvedic anthelmintic drugs, viz. Krimimudgar Ras, Kriminol and Vidangasava in relation to the synthetic broad-spectrum anthelmintic drugs, praziquantel and albendazole. The in vitro testing of Ayurvedic anthelmintics was done against an intestinal cestode, Raillietina sp. and a nematode, Syphacia obvelata, employing 10 mg/ml, 30 mg/ml and 50 mg/ml concentrations of each medicine. The anthelmintic efficacy was judged on the basis of paralysis and mortality time of worms after exposing to these Ayurvedic drugs. Of the three tested Ayurvedic medicines, Krimimudgar ras (KR) showed the most prominent efficacy, against both the cestode and nematode parasites. At 50 mg/ml concentration, KR caused mortality of cestodes in $7.53{\pm}0.15hr$, and of nematodes in $7.61{\pm}0.19hr$. Vidangasava was found to be comparatively less effective against the tested helminth parasites. The results of this study indicate that Ayurvedic formulations do possess significant anthelmintic effects, however, an evidence-based research is required to validate all currently used Ayurvedic anthelmintics, using proper controlled studies.

SPECIAL CONSIDERATION ON THE RADARSAT REPEAT-PASS SAR INTERFEROMETRY

  • Kim, Sang-Wan;Won, Joong-Sun;Moon, Wooil-M.
    • Proceedings of the KSRS Conference
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    • 1999.11a
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    • pp.474-478
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    • 1999
  • SAR interferometry (InSAR) using the space-borne Synthetic Aperture Radar (SAR) have recently become one of the most effective tools monitoring surface changes caused by landslides, earthquakes, subsidences or volcanic eruption. This study focuses on examining the feasibility of InSAR using the RADARSAT data. Although the RABARSAT SAR with its high resolution and variable incidence angle has several advantages for repeat-pass InSAR, it has two key limitations: first, the orbit is not precisely known; and second, RADARSAT's 24-day repeat pass interval is not very favourable for retaining useful coherence. In this study, two pairs of RADARSAT data in the Nahanni area, NWT, Canada have been tested. We will discuss about the special consideration required on the interferometric processing steps specifically for RADARSAT data including image co-registration, spectral filtering in both azimuth and range, estimation of the interferometric baseline, and correction of the interferogram with respect to the "flat earth" phase contribution. Preliminary results can be summarized as: i) the properly designed azimuth filter based upon the antenna characteristic improves coherence considerably if difference in Doppler centroid of the two images is relatively large; ii) the co-registration process combined by fringe spectrum and amplitude cross-correlation techniques results in optimal matching; iii) the baseline is not always possible to be estimated from the definitive orbit information.

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OBSERVATION OF SPECTRAL CHARACTERISTICS FOR SOIL CONTAMINANTS

  • Choe Eun-Young;Kim Kyoung-Woong;Lee Sung-Soon;Chi Kwang-Hoon
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.422-425
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    • 2005
  • Spectral characteristics depending on soil constituents and their proportion in a soil were firstly studied for monitoring of soil contamination using hyperspectral remote sensing. The reflectance spectra of heavy metals in soils were investigated in the VIS-NIR-SWIR regions (400-2500 nm) to observe spectral variation as a function of constituents and concentrations. Commercial kaolinite soils mixed with lead, copper, arsenic, and cadmium were used as synthetic soil samples for spectral measurement. In case of copper, relatively spectrally active regions was observed with some band shift whereas other heavy metals had only simple spectral variations expected to be related to the sorption phase and the amount of metal onto kaolinite. The reflectance spectrum of each metal on kaolinite could be identified in VIS-NIR region.

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Adsorption of U(VI), Fe(II), Sm(III) Ions on OenNen-Styrene DVB Synthetic Resin (OenNen-Styrene DVB 합성수지에 의한 U(VI), Fe(II), Sm(III) 이온들의 흡착)

  • Lee, Chi-Young;Kim, Joon-Tae
    • Journal of environmental and Sanitary engineering
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    • v.22 no.3
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    • pp.77-87
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    • 2007
  • The ion exchange resins have been synthesized from chlormethyl styrene - 1,4 - divinylbenzene(DVB) with 1%, 3%, and 5%-crosslinking and macro cyclic ligand of OenNen-$H_4$ by copolymerization method and the adsorption characteristics of uranium(VI), iron(II) and samarium(III) metallic ions have been investigated in various experimental conditions. The synthesis of these resins was confirmed by content of chlorine, element analysis, and IR-spectrum. The effects of pH, time, dielectric constant of solvent and crosslink on adsorption of metallic ions were investigated. The uranium ion was showed fast adsorption on the resins above pH 3. The optimum equilibrium time for adsorption of metallic ions was about two hours. The adsorption selectivity determined in ethanol was in increasing order uranium ${UO_2}^{2+}>Fe^{2+}>Sm^{3+}$ ion. The adsorption was in order of 1%, 3%, and 5% crosslink resin and adsorption of resin decreased in proportion to order of dielectric constant of solvent.

Development of Polymeric Water Absorbent Film(PWAF) for the Collection of Size-classified Fog Droplets

  • Ma, Chang-Jin;Mikilo-kasahara;Park, Kum-Chan
    • Journal of Korean Society for Atmospheric Environment
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    • v.17 no.E1
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    • pp.17-24
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    • 2001
  • For the purpose of collecting fog droplets as a function of size a new sampling method was developed in this study. Formation of 100$\pm$10㎛ thickness of polymeric water absorbent film (PWAF) on a nuclepore filter could be successfully realized. Also applicability of particle induced X-ray emission (PIXE) method to the chemical analysis of size-segregated fog droplets collected on PWAF was examined experimentally with synthetic fog droplets generated from a nebulizer. Absorption capacity of S-PAAS polymeric water absorbent shows marked decreases in the range less than 1 wt% and slight decrease between 1 and 3.5 wt% of every salt concentration. Dependency of absorption capacity on pH shows the maximum at pH 7. No apparent peak which can influence the quantitative analysis of elements dissolved and suspended in fog droplets was found at PIXE spectrum of PWAF blank. PWAF kept the original shape without rupture under the PIXE analytical conditions of beam intensity for 10 to 60 nA and irradiation time of 4∼5 min. It should be said that the proposed new technique in the work is helpful to get more detailed information of fog droplets, to clarify the fog formation processes, and to develop a model of acid deposition process.

Melatonin in Psychiatric Disorders (멜라토닌과 정신과 질환)

  • Lee, Jin-Seong;Kim, Sung-Gon;Kim, Ji-Hoon;Jung, Woo-Young;Park, Ji-Hoon
    • Sleep Medicine and Psychophysiology
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    • v.22 no.1
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    • pp.5-10
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    • 2015
  • The secretion of melatonin exhibits a circadian rhythm entrained with the sleep-wake cycle. An alteration of this secretory rhythm has been found in various psychiatric disorders. This review summarizes the regulation of melatonin and its relationship to the circadian rhythm, major depressive disorder, bipolar disorder, seasonal affective disorder, Alzheimer's disease and autism. The review also looks at the effect of melatonin and melatonin agonist on sleep and symptoms of depression, bipolar disorder and seasonal affective disorder. In Alzheimer's disease, the circadian rhythm alterations are associated with the change of melatonin levels and melatonin receptors. It has been reported that melatonin and melatonin synthetic enzyme levels decrease in autism spectrum disorder.

Preparation and Photoluminescent Properties of Ca2PO4Cl Activated by Divalent Europium

  • Park, In Yong
    • Journal of the Microelectronics and Packaging Society
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    • v.23 no.4
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    • pp.63-67
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    • 2016
  • Divalent europium-activated $Ca_2PO_4Cl$ phosphor powders were prepared by a chemical synthetic method followed by heat treatment in reduced atmosphere, and the crystal structures, morphologies and photoluminescence properties of the powders were investigated by x-ray powder diffraction, scanning electron microscope and spectrometer. The effect of Ca/P mole ratio at the starting materials on the final products was evaluated. The optimized synthesis condition obtained in this study was Ca/P mole ratio of 2.0. The present phosphor materials had higher photoluminescence intensity and better color purity than the commercial blue phosphor powders, $(Ca,Ba,Sr)_{10}(PO_4)_6Cl_2:Eu^{2+}$. The result of excitation spectrum measurement indicated that the excitation efficiency of the synthesized powders was higher for the long-wavelength UV region than that of the commercial phosphor. It was thus concluded that the samples prepared in this study can be successfully applied for the light-emitting devices such as LED excited with long-wavelength UV light sources.