• Research in Plant Disease
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• v.15 no.3
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• pp.175-182
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• 2009

We investigated the effect of the infection times and infection degrees at transplanting time of Zucchini yellow mosaic virus (ZYMV) on the growth and yield of cucumber plants at the semi-forcing and the retarding culture in 2007. When cucumber was inoculated with ZYMV at transplanting time, 15, 30, 45, 60, and 75 days after transplanting, vine length, internode length, number of leaf of the plants and marketable yield largely decreased as the cucumber infected earlier. The regression models were obtained between the disease incidence levels at 20 days after transplanting as the inoculation degrees and the marketable yield of cucumber: y = $9333.1e^{-0.0317x}$ ($R^2$ = 0.8946) at the semi-forcing culture and y = $14695e^{-0.0303x}$ ($R^2$ = 0.8735) at the retarding culture. And the cucumber yield loss regression models between the symptoms incidence days from the final harvesting time and the rates of yield decrease were expressed as y=1.0851x - 6.7067 ($R^2$ = 0.9567) at the semi-forcing culture andy=1.0439x + 2.1321 ($R^2$ = 0.9674) at the retarding culture.

• Science of Emotion and Sensibility
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• v.5 no.4
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• pp.77-84
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• 2002

In this paper, we propose the NAVER, a general framework for multipurpose virtual environments, and introduce the case study of evaluating car prototypes using cave-like systems. As a framework to implement variant applications in virtual environment, NAVER is extensible, reconfigurable and scalable. NAVER consists of several external modules (Render Server, Control Server and Device Server), which communicate each other to share states and user-provided data and to perform their own functions. NAVER supports its own scripting language based on XML which allows a user to define variant interactions between objects in virtual environments as well as describe the scenario of an application. We used NAVER to implement the system for evaluating car prototyes in a CAVE-like virtual environment system. The CAVE-like virtual environment system at KIST consists three side screens and a floor screen (each of them is a square with side of 2.2m), four CRT projectors displays stereoscopic images to the screens, a haptic armmaster, and a 5.1 channel sound system. The system can provide a sense of reality by displaying auditory and tactile senses as well as visual images at the same time. We evaluate car prototypes in a CAVE-like system in which a user can observe, touch and manipulate the virtual installation of car interior.

• Journal of Korean Society of Steel Construction
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• v.21 no.3
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• pp.221-232
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• 2009

The load distribution factor (LDF) values of simplified composite H beam panel bridges (SCHPBs) that were subjected to one lane and two lane loads were investigated using three dimensional finite element analyses with the computer program ABAQUS (2007). This study considered some design parameters such as the slab thickness, the steel plate thickness, the span length, and the continuity of the SCHPBs in the development of new LDFs. The distribution values that were obtained from these analyses were compared with those from the AASHTO Standard, LRFD, and the equations presented by Tarhini and Frederick, Huo et al., Back and Shin, and Cai. The AASHTO Standard distribution factors for SCHPBs were found to be very conservative. Sometimes, the distribution values from the finite element analyses for interior girders were similar to the results of the AASHTO LRFD, whereas the values for exterior girders were conservative in most cases. The new distribution values that were presented in this study produced LDFs that are more conservative than those from the finite element method. For the simple application of the design to SCHPBs, bridge engineers can use 0.42 for the interior girder and 0.32 for the exterior girder. The proposed values improve the current design procedure for the LDF problem and increase SCHPB design efficiency.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.3
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• pp.619-630
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• 2009

To investigate the hair growth activity of fractions and extract of Arisaematis Rhizoma in the hair removed skin of normal and spontaneous alopecia areata model in C57B/6N mice. These experiments were performed with the macroscopic, microscopic, immunohistochemical(VEGF, c-kit, PKC-${\alpha}$, TGF and FGF) and RT-PCR(TGF-${\beta}$, IGF, prolactin and placenta lactogen) methods. The results were as follows: Macroscopic observation after topical application of vehicle, 50% EtOH as control and extract of Arisaematis Rhizoma to the hair removed skin of C57BL/6N mice on the 9th, 11th and 15th day. Extensive hair growth activity was observed in treated group with extract of Arisaematis Rhizoma on the 9th, 11th and 15th day. In Arisaematis Rhizoma extracts treated group, hair follicles of middle stage of anagen was observed and it were grown down to subcutaneous tissue of skin in all the normal mice on 15th day. But in control group, most of hair follicles of telogen phase was observed in skin. The treatment of extract of Arisaematis Rhizoma increased expression of IGF(145%) and placenta lactogen(108%) in the skin of normal C57BL/6N mice on the 11th day compared to control group(100%). But expression of TGF-${\beta}$(90%) and prolactin(91%) decreased in the skin of normal C57B/6N mice on the 11th day compared to control group(100%). After application of fractions(chloroform, ethyl acetate and water fractions) of Arisaematis Rhizoma extract for 9th day, hair growth effect was observed in whole skin area in 50% of normal mice. But in control group, hair growth effect was not observed in whole skin area of normal mice. Immunoreactive density of VEGF, c-kit, PKC-${\alpha$ and FGF in skin of fractions of Arisaematis Rhizoma extracts was strongly stained in epidermis, bulge, secondary hair germ cells, cutaneous trunci m., subcutaneous tissue, root sheath compare to control group on the 9th day. In spontaneous alopecia areata model, The hair growth activity of Arisaematis Rhizoma extrat treated group(75%) was observed to be strong compared to control group(O%) on 7th day. These experiments suggest that fractions and extracts of Arisaematis Rhizoma may stimulate the topical hair growth activity. Thus it can be useful for treatment of alopecia areata.

• Korean Journal of Organic Agriculture
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• v.18 no.4
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• pp.573-586
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• 2010

This study was carried out to evaluate characteristics of Chrysanthemum sp. and to bioassay Tetranychus urticae, Nilaparvata lugens, and Aphis gossypii by different extracts part and method. Flower type of Chrysanthemum sp. line was anemone except 0706 line which was pompon. The flowering date was from April to June but 0721 line kept up November. They could overwinter except 0706 line. The Ethanol extracts of 0718 line of flower was high mortality as 63.8% on Tetranychus urticae. Ethanol mixed emulsifier extracts were the highest mortality as 69.4% at 5 days after. Mortality in water extract was lower than in ethanol and ethanol mixed emulsifier extracts. Ethanol mixed emulsifier extracts were higher mortality as 69.4% at 5 days after in 0718 line on Nilaparvata lugens. Mortality in water extract was lower than in ethanol and ethanol mixed emulsifier extracts. On Aphis gossypii, Chrysanthemum flower extracts could decrease the density of aphids in early days but the density of that was increase as time goes by because aphids produce offspring.

• Korean Journal of Organic Agriculture
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• v.18 no.4
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• pp.559-571
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• 2010

This study carried out to evaluate toxicology of Chrysanthemum cinerariaefolium and Melia azedarach against natural enemies in the laboratory, and the diamond backmoth, Plutella xylostella, on chinese cabbage. In the evaluation of the toxicity on predatory mite of phytoseiid Phytoseiulus persimilis, Hypoaspis aculeifer, Amblyseius cucumeris, A. wormersleyi, A. swirskii, the two plant extracts were classified into moderate selective toxicity as recommended by international organization of biocontrol (IOBC). The mummies parasitic natural enemies, Trichogramma evanescens, Aphidius ervi, Aphidius colemani, Eretmocerus eremicus, Encarsia formosa were found to be relatively safe to the plant extracts except Eretemocerus eremicus. In the field study for the control of diamondback moth, Plutella xylostella, single spray of C. cinerariefolium indicated that the control effect dropped from 21th days after the spraying. In the 3 times of spray with 7 says intervals, the mortality effect low at the beginning, but increased to 91.1 at 21 days after spraying. Single spray of M. azedarach showed a 96.7% mortality on P. xylostella at 14 days after spraying, and thereafter decreased. In the three times of spray with 7 days intervals of M. azedarach, the mortality of P. xylostella was 100% at 14 days and its effect was maintained to 28 days after treatment. Consequently, it was suggested that M. azedarach be sprayed before C. cinerariaefolium application.

• Journal of the Korean Society for Nondestructive Testing
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• v.26 no.2
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• pp.99-107
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• 2006

Magnetic nondestructive testing is very useful far detecting a crack on the surface or near of the surface of the ferromagnetic materials. The distribution of the magnetic flux leakage (DMFL) on a specimen has to be obtained quantitatively to evaluate the crack. The magnetic camera is proposed to obtain the DMFL at the large lift-off. The magnetic camera consists of a magnetic source, magnetic lens, analog to digital converters (ADCs), interface, and computer. The magnetic leakage fields or the distorted magnetic fields from the object, which are concentrated on the magnetic lens, are converted to analog electrical signals tv arrayed small magnetic sensors. These analog signals are converted to digital signals by the ADCs, and are stored, imaged, and processed by the interface and computer. However the magnetic camera has limitations with respect to converting and switching speed, full range and resolution, direct memory access (DMA), temporary storage speed and volume because common ADCs were used. Improved techniques, such as those that introduce the operational amplifier (OP-Amp), amplify the signal, reduce the connection line, and use the low pass filter (LPF) to increase the signal to noise ratio are necessary. This paper proposes the exclusive embedded ADC including OP-Amp, LPF, microprocessor and DMA circuit for the magnetic camera to satisfy the conditions mentioned above.

• Applied Chemistry for Engineering
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• v.21 no.5
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• pp.522-526
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• 2010

Heat storage application techniques can be categorized into the sensible heat storage and the latent heat storage according to the method of heat storage. Heat storage is the way of saving remaining heat when heating and cooling loads are light, and then using it when the heating and cooling loads are heavy. Latent heat storage is defined as the method of saving heat by using substances which have high potential heat when phase change is in the range of a certain temperature and when heat storage space is small, compared to those of sensible heat storage and it is possible that absorption and emission of heat at a certain temperature. This study is conducted to save energy when either air-conditioning or heating is operated in a building. We have tried to find out the essential properties of matter and the optimum mixing rate about cement and gypsum for building materials, which have been widely used for proper phase change materials (PCM), when thermal environment property is applied. So we obtained the result of the cooling delay effect about 19% with heat storage mortar containing 3 wt% of PCM.

• Research in Plant Disease
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• v.14 no.3
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• pp.182-186
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• 2008

Recently organic farming practice of rice has been emerged in Korea, but one of the major limiting factor is the no effective environmental-friendly agro-materials to control major plant diseases. Bordeaux mixture has been used effectively as a preventive agro-chemical. The aim of this study was to investigate efficacy of Bordeanux mixture on control of rice blast caused by Magnaporthe grisea which is one of the disruptive rice diseases in world-wide. In greenhouse experiment, pre-treatment of 6-6 type of Bordeaux mixture before inoculation of spore suspension of M. grasea showed 71 % of control value. In field experiment, preventive applications of 4-8 and 6-6 types of Bordeaux mixture showed over 71 % of the control value. Chemical injury on rice leaves were not found in the application concentrations of all types of Bordeaux mixture, but observed in applications of Bordeaux mixtures between 30 and 100 diluted concentrations. This results indicate Bordeaux mixture can be used as an effective environmental-friendly agro-chemical to control rice blast disease in the field.

• Research in Plant Disease
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• v.23 no.2
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• pp.177-185
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• 2017

Bacillus amyloliquefaciens LM11 was isolated from the feces of larvae of the rhino beetle and showed strong antifungal activities against various phytopathogenic fungi by producing biosurfactants. In this study, our overall goal was to determine relationship between biosurfactants produced from the LM11 strain and its role in growth inhibition of phytopathogenic fungi. Production and expression levels of B. amyloliquefaciens LM11 biosurfactants were significantly differed depending on growth phases. Transcriptional and biochemical analysis indicated that the biosurfactants of the LM11 strain were greatly enhanced in late log-phase to stationary phase. Inhibitions of phytopathogenic mycelial growth and spore germination were directly correlated (P<0.001, R=0.761) with concentrations of the LM11 cell-free culture filtrates. The minimum inhibitory surface tension of the culture filtrate of the B. amyloliquefaciens LM11 grown in stationary phase to inhibit mycelial growth of the phytopathogenic fungi was 38.5 mN/m (P<0.001, R=0.951-0.977). Our results indicated that the biosurfactants of B. amyloliquefaciens LM11 act as key antifungal metabolites in biocontrol of plant diseases, and measuring surface tension of the cell-free culture fluids can be used as an easy indicator for optimal usage of the biocontrol agents.