• Korean Journal of Soil Science and Fertilizer
• /
• v.46 no.4
• /
• pp.237-244
• /
• 2013

Radar remote sensing is appropriate for monitoring rice because the areas where this crop is cultivated are often cloudy and rainy. Especially, Synthetic Aperture Radar (SAR) can acquire remote sensing information with a high temporal resolution in tropical and subtropical regions due to its all-weather capability. This paper analyzes the relationships between backscattering coefficients of rice measured by RADARSAT-2 SAR and growth parameters during a rice growth period. We examined the temporal variations of backscattering coefficients with full polarization. Backscattering coefficients for all polarizations increased until Day Of Year (DOY 222) and then decreased along with Leaf Area Index (LAI), fresh weight, and Vegetation Water Content (VWC). Vertical transmit and Vertical receive polarization (VV)-polarization backscattering coefficients were higher than Horizontal transmit and Horizontal receive polarization (HH)-polarization backscattering coefficients in early rice growth stage and HH-polarization backscattering coefficients were higher than VV-polarization backscattering coefficients after effective tillering stage (DOY 186). Correlation analysis between backscattering coefficients and rice growth parameters revealed that HH-polarization was highly correlated with LAI, fresh weight, and VWC. Based on the observed relationships between backscattering coefficients and variables of cultivation, prediction equations were developed using the HH-polarization backscattering coefficients.

• Journal of the Korean Applied Science and Technology
• /
• v.26 no.1
• /
• pp.60-68
• /
• 2009

In this work, the synthetic approaches for a series of aminopyrimiclinylmethanone derivatives 1a-i, which versatile biological activities such as antibacterial and anticancer activities are expected from a structural point of view, were described. Nicotinic acid was converted to (2-methylsulfonylpyrimidin-4-yl) (pyridin-3-yl)methanone, a key intermediate, which was reacted with nucleophiles to yield the desired aminopyrimidinylmethanone derivatives 1a-i bearing various substituents.

• Journal of the Korean Ceramic Society
• /
• v.44 no.2 s.297
• /
• pp.89-92
• /
• 2007

PbSe, with a band gap in the mid-infrared and a samll effective mass, is an interesting material for optical and electrical applications in infrared region. Various colloidal synthetic routes for synthesizing PbSe quantum dot nanoparticles have been developed in the last couple of years. In this work, stable colloidal solutions containing crystalline PbSe particles in the order of 5-15 nm were synthesized using different amount of acetic acid in high boiling coordinating solvents. The size and shape of PbSe nanoparticles was greatly influenced by coexistence of acetic acid in synthetic medium. It was observed by TEM that the shape of PbSe nanoparticles with different amount of acetic acid was changed from spherical to cube or star types.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• v.29 no.1
• /
• pp.147-152
• /
• 2005

This paper proposes an evaluates a new approach to detect ships as targets from Radarsat-1 SAR (Synthetic Aperture Radar) imagery in the vicinity of Korean peninsula. To be more specific, a labeling technique and morphological filtering in conjunction with some other methods are employed to automatically detect the ships. From the test, the ships are revealed to be detected. For ground truth data, information from a radar system is used, which allows assessing accuracy of the approach. The results showed that the proposed approach has the high potential in automatically detecting the ships.

• The Plant Pathology Journal
• /
• v.29 no.1
• /
• pp.1-9
• /
• 2013

Plants are attacked by various phytopathogenic fungi. For many years, synthetic fungicides have been used to control plant diseases. Although synthetic fungicides are highly effective, their repeated use has led to problems such as environmental pollution, development of resistance, and residual toxicity. This has prompted intensive research on the development of biopesticides, including botanical fungicides. To date, relatively few botanical fungicides have been registered and commercialized. However, many scientists have reported isolation and characterization of a variety of antifungal plant derivatives. Here, we present a survey of a wide range of reported plant-derived antifungal metabolites.

• Proceedings of the Korea Society of Environmental Toocicology Conference
• /
• 2004.11a
• /
• pp.67-67
• /
• 2004

• Journal of Environmental Health Sciences
• /
• v.48 no.3
• /
• pp.167-175
• /
• 2022

Background: Disinfection is essential to provide drinking water from a water source. The disinfection process mainly consists of the use of chlorine and ozone, but when chlorine is used as a disinfectant, the problem of disinfection by-products arises. In order to resolve the issue of disinfection by-products, electro-chlorination technology that produces chlorine-based disinfectants from salt water through electrochemical principles should be applied. Objectives: This study surveys the possibility of optimally producing active chlorine from synthetic NaCl solutions using an electro-chlorination system through RSM. Methods: Response surface methodology (RSM) has been used for modeling and optimizing a variety of water and wastewater treatment processes. This study surveys the possibility of optimally producing active chlorine from synthetic saline solutions using electrolysis through RSM. Various operating parameters, such as distance of electrodes, sodium chloride concentration, electrical potential, and electrolysis time were evaluated. Results: Various operating parameters, such as distance of electrodes, sodium chloride concentration, electrical potential, and electrolysis time were evaluated. A central composite design (CCD) was applied to determine the optimal experimental factors for chlorine production. Conclusions: The concentration of the synthetic NaCl solution and the distance between electrodes had the greatest influence on the generation of hypochlorite disinfectant. The closer the distance between the electrodes and the higher the concentration of the synthetic NaCl solution, the more hypochlorous acid disinfectant was produced.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.27 no.10
• /
• pp.138-145
• /
• 1990

This paper present a rule-based speech synthesis method for improving the naturalness of synthetic speech and using the small data base based on demisyllable units. A 12-pole Linear Prediction Coding method is used to analyses demisyllable speech signals. A syllable and vowel concatenation rule is developed to improve the naturalness and intelligibility of the synthetic speech. in addiion, phonological structure transform rule using neural net and prosody rules are applied to the synthetic speech.

• Bulletin of the Korean Chemical Society
• /
• v.11 no.4
• /
• pp.323-327
• /
• 1990

The synthesis and some biological properties of $7{\beta} $-[2-(Z)-(2-aminothiazole-4-yl)-2-(N-substitutedcar bonyl)ethoxyiminoacetamido]-3-vinyl-3-cephem-4- carboxylic acid are described. The effect of substituents on the carbamoly group in the 7-side chain were investigated in order to improve antibacterial activities. Two of these new orally active $7{\beta} $-lactam derivatives showed wide expanded antimicrobial activities against Gram-positive and Gram-negative bacteria, including Pseudomonas aeruginosa, as well as good stability to $7{\beta} $ -lactamases.

• Resources Recycling
• /
• v.20 no.3
• /
• pp.68-76
• /
• 2011

For the separation of aluminum and iron from platinum mixtures, extraction resins were synthesized and separation efficiencies were compared with those by commercial one, $P_{204}$. During synthesis, the suspension polymerization method was adopted with D2EHPA as an extractant. Also, benzoyl peroxide as a starter was divided into 3parts and injected for the uniform size and dispersion of resin particles. Comparison tests resulted in 100% separation of Fe and Pt for both synthetic and $P_{204}$ resins. In case of Al and Pt, synthetic and $P_{204}$ resin gave extraction efficiencies of 99.9% and 98.9%, respectively. Difference in extractant contents of synthetic resin(61.8%) and $P_{204}$(60%) was considered to give differences in separation efficiencies of aluminum and iron elements. For both resins, separation efficiencies of Al and Fe increased up to $55^{\circ}C$. According to FT-IR analyses of both resins, specific peaks of D2EHPA and crosslinked polystyrene were identified at the wavenumber of $1000cm^{-1}$ and $2900cm^{-1}$ respectively.