• Journal of Astronomy and Space Sciences
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• v.26 no.4
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• pp.425-438
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• 2009

We reevaluate the Burton equation (Burton et al. 1975) of predicting Dst index using high quality hourly solar wind data supplied by the ACE satellite for the period from 1998 to 2006. Sixty magnetic storms with monotonously decreasing main phase are selected. In order to determine the injection term (Q) and the decay time ($\tau$) of the equation, we examine the relationships between $Dst^*$ and $VS_s$, ${\Delta}Dst^*$ and $VS_s$, and ${\Delta}Dst^*$ and $Dst^*$ during the magnetic storms. For this analysis, we take into account one hour of the propagation time from the ACE satellite to the magnetopause, and a half hour of the response time of the magnetosphere/ring current to he solar wind forcing. The injection term is found to be $Q(nT/h)\;=\;-3.56VS_s$ for $VS_s$ > 0.5mV/m and Q(nT=h) = 0 for $VB_s\;{\leq}\;0.5mV/m$. The $\tau$ (hour) is estimated as $0.060Dst^*\;+\;16.65$ for $Dst^*$ > -175nT and 6.15 hours for $Dst^*\;{\leq}\;-175nT$. Based on these empirical relationships, we predict the 60 magnetic storms and find that the correlation coefficient between the observed and predicted $Dst^*$ is 0.88. To evaluate the performance of our prediction scheme, the 60 magnetic storms are predicted again using the models by Burton et al. (1975) and O'Brien & McPherron (2000a). The correlation coefficients thus obtained are 0.85, the same value for both of the two models. In this respect, our model is slightly improved over the other two models as far as the correlation coefficients is concerned. Particularly our model does a better job than the other two models in predicting intense magnetic storms ($Dst^*\;{< \atop \sim}\;-200nT$).

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.34 no.1
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• pp.85-95
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• 1998

The broadband ultrasonic transducers have been designed to use in obtaining the broadband echo signals from fish schools in relation to the identification of fish species. The broadening of bandwidth was achieved by attaching double acoustic matching layers on the front face of a Tonpilz transducer consisted of an aluminum head, a piezoelectric ring, a brass tail and to evaluate the performance characteristics, such as the transmitting voltage response(TVR) of transducers. The constructed transducers were tested experimentally and numerically by changing the parameters such as impedances and thicknesses of the head, tail and matching layers, in the water tank. Also, the developed transducer was excited by a chirp signal and the received chirp waveforms were analyzed. According to the measured TVR results, the available 3 dB bandwidth of the transducer with double matching layers of an $Al_O_3/epoxy$ composite of 7 mm thick and a polyurethane window of 18 mm thick was 7.3 kHz with a center frequency of 38.8 kHz, and the maximum and the minimum values of the TVR in this frequency region were 135.7 dB and 132.7 dB re $1\;{\mu}Pa/V$ at 1 m, respectively. Also, the available 3 dB bandwidth of the transducer with double matching layers of an $Al_O_3/epoxy$ composite of 11 mm thick and a polyurethane window of 15 mm thick was 6.2 kHz with a center frequency of 38.6 kHz, and the maximum TVR value in the frequency region was 136.3 dB re $1\;{\mu}Pa/V$ at 1 m. Reasonable agreement between the experimental results and the numerical results for the TVR of the developed transducers was achieved. The frequency dependant characteristics of experimentally observed chirp signals closely matched to the measured TVR results. These results suggest that there is potential for increasing the bandwidth by varying other parameters in the transducer design and the material of the acoustic matching layers.

• The Korean Journal of Nuclear Medicine
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• v.33 no.1
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• pp.94-99
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• 1999

Purpose: Radiation-induced chromosomal damage and apoptosis were compared in human lymphocytes. Materials and Methods: Peripheral lymphocytes from 10 normal volunteers (6 males, 4 females, age range $23{\sim}41$ years) were irradiated by gamma rays from a cell irradiator. Doses of irradiation were 0 (control), 0.18, 2, 5, 10, 20 and 25 Gy. Irradiated lymphocytes were examined by metaphase analysis for chromosomal aberrations and by flow cytometry for apoptosis. Results of both studies were compared according to dose. Results: Number of dicentric and ring chromosomes (D+R) was $0.5{\pm}0.53$ at baseline, which was significantly increased after radiation according to the dose. The fraction of cells showing annexin V-fluorescein isothiocyanate uptake was $0.51{\pm}$0.39%, which increased to $3.58{\pm}1.85%$ by 2 Gy irradiation, and then decreased. The fraction of cells showing propidium iodide (PI) uptake was $0.52{\pm}0.12%$, which significantly increased according to dose (upto $15.64{\pm}5.99%$ by 20 Gy irradiation). D+R and PI uptake were well correlated (r=0.84, p<0.001). Conclusion: Radiation-induced chromosomal aberration was correlated to nuclear uptake of PI, a marker of late apoptosis.

• Journal of Astronomy and Space Sciences
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• v.22 no.4
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• pp.409-418
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• 2005

Magnetospheric substorms occur frequently during magnetic storms, suggesting that the two phenomena are closely associated. We can investigate the relation between magnetospheric substorms and magnetic storms by examining the correlation between AE and Dst indices. For this purpose, we calculated the monthly cumulative AU, $\mid{AL}\mid$ and $\mid{Dst}\mid$ indices. The correlation coefficient between the monthly cumulative $\mid{AL}\mid$ and $\mid{Dst}\mid$ index is found to be 0.60, while that between monthly cumulative AU and $\mid{Dst}\mid$ index is 0.28. This result indicates that substorms seem to contribute to the development of magnetic storms. On the other hand, it has been reported that the interplanetary electric field associated with southward IMF intensifies the magnetospheric convection, which injects charged particles into the inner magnetosphere, thus developing the ring current. To evaluate the contribution of the interplanetary electric field to the development of the storm time ring current belt, we compared the monthly cumulative interplanetary electric field and the monthly cumulative Dst index. The correlation coefficient between the two cumulative indices is 0.83 for southward IMP and 0.39 for northward IMF. It indicates that magnetospheric convection induced by southward IMF is also important in developing magnetic storms. Therefore, both magnetospheric substorm and enhanced magnetospheric convection seem to contribute to the buildup of magnetic storm.

• Journal of Practical Agriculture & Fisheries Research
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• v.11 no.1
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• pp.79-94
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• 2009

The research project was conducted to develop a paper bagging machine for grape. This technology was aimed to highly reduce a labor for paper bagging in grape and bakery. In agriculture labor and farm population has rapidly decreased since 1980 in Korea so there was so limit in labor. In particular there is highly population in women and old age at rural area and thus labor cost is so high. Therefore a labor saving technology in agricultural sector might be needed to be replaced these old age with mechanical and labor saving tool in agriculture. The following was summarized of the research results for development of a paper bagging machine for grape. 1. Development of a new paper bagging machine for grape - This machine was designed by CATIA VI2/AUTO CAD2000 programme. - A paper bagging machine was mechanically binded a paper bag of grape which should be light and small size. This machine would be designed for women and old age with convenience during bagging work at the field site. - This machine was manufactured with total weight of less than 350g. - An overage bagging operation was more than 99% at the actual field process. - A paper bagging machine was designed with cartridge type which would be easily operated between rows and grape branches under field condition. - The type of cartridge pin was designed as a C-ring type with the length of 500mm which was good for bagging both grape and bakery. - In particular this machine was developed to easily operated among vines of the grape trees. 2. Field trials of a paper bagging machine in grape - There was high in grape quality as compared to the untreated control at the application of paper bagging machine. - The efficiency of paper bagging machine was 102% which was alternative tool for the conventional. - The roll pin of paper bagging machine was good with 5.3cm in terms of bagging precision. - There was no in grape quality between the paper bagging machine and the conventional method. - Disease infection and grape break was not in difference both treatments.

• Applied Biological Chemistry
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• v.50 no.3
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• pp.147-153
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• 2007

To search for a molecular design of a new breast cancerous inhibitory active compound, 2D-QSAR and HQSAR between the substituents of flavopiridol analogues as substrates and their breast cancerous inhibitory activities against MCF-7 cell were analyzed and discussed quantitatively. It was found that the dispersion with molecule and steric hindrance with substituents will have a tremendous impact on the inhibitory activities from the 2D-QSAR model (1). Also, MR constant is better than that of MS constant as animportant factor. The inhibitory activities from 2D-QSAR model (2) were dependent upon the optimum MR constant (MR = 126 $Cm^3/mol$). Optimized HQSAR model (V) exhibited the best predictability of the inhibitory activities based on the cross-validated $r^2_{cv}$($q^2$= 0.583) and non-cross-validated conventional coefficient ($r^2_{ncv}$= 0.982). From the contribution maps, the inhibitory activity by the imino group on $C_9$ atom was higher than that of the hydroxyl group of $C_8$ atom on the A ring in molecule. Therefore, we can confirm that the dispersion by substituents in molecule is the most important factor in inhibitory activities against MCF-7 cell.

• Journal of Korean Society of Forest Science
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• v.99 no.6
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• pp.855-862
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• 2010

The objectives of this study were to analyze vegetation types and stand structures of the red pine (Pinus densiflora) in Kangwon southern region for stable and sustainable forest management. The pine forests in study sites were classified into 4 communities, 2 groups, so total 6 vegetation units. Species with high constance degree were Quercus mongolica, Rhus trichocarpa, Lindera obtusiloba, Lespedeza maximowiczii, Quercus serrata, Spodiopogon sibiricus, Aster scaber and Fraxinus sieboldiana. In the importance value(I.V.) analysis of each layer, P. densiflora showed highly in tree layer while in other layers competitive broad-leaved species such as Quercus spp. were high. P. densiflora also showed large size of DBH, while broad-leaved species distributed middle and small DBH. The annual ring growths of P. densiflora and competitive broadleaved species were variable according to area, site condition, tree year and species, it is considered that appropriate silvicultual practice methods should be employed to remove rival broad-leaved species for maintenance of sustainable red pine forests considering the characteristics of each stand.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.407-410
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• 2002

Monochromatic x-ray CT has several advantages over conventional CT, which utilizes bremsstrahlung white x-rays from an x-ray tube. There are several methods to produce such monochromatic x-rays. The most popular one is crystal diffraction monochromatization, which has been commonly used because of the fact that the energy spread is very narrow and the energy can be changed continuously. The alternative method is the use of fluorescent x-ray, which has several advantages such as large beam size and fast energy change. We have developed a parallel-beam and a fan-beam monochromatic x-ray CT, and compared some characteristics such as accuracy of CT numbers between those systems. The fan beam monochromatic x-rays were generated by irradiating target materials by incident white x-rays from a bending magnet beam line NE5 in 6.5 GeV Accumulation Ring at Tukuba. The parallel beam monochromatic x-rays were generated by using a silicon double crystal monochromator at the bending magnet beam line BL-20BM in Spring-8. A Cadmium telluride (CdTe) 256 channel array detector with 512mm sensitive width capable of operating at room temperature was used in the photon counting mode. A cylindrical phantom containing eight concentrations of gadolinium was used for the fan beam monochromatic x-ray CT system, while a phantom containing acetone, ethanol, acrylic and water was used for the parallel monochromatic x-ray CT system. The linear attenuation coefficients obtained from CT numbers of those monochromatic x-ray CT images were compared with theoretical values. They showed a good agreement within 3%. It was found that the quantitative measurement can be possible by using the fan beam monochromatic x-ray CT system as well as a parallel beam monochromatic X-ray CT system.

• YAKHAK HOEJI
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• v.36 no.1
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• pp.1-6
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• 1992

Irradiation of phenolbetaine in a stream of nitrogen produced 8,14-cycioberbine[1]. Compound[1] was treated with 10% HCl solution to give the 8-hydroxycycloberbine[2] in 67.7% yield. Subsequently addition of ethylchloroformate to the compound[2] gave rise to the 8-hydroxy-7-ethylcarboxy-9, 10-dimethoxy-2, 3-methylenelioxy-13-oxo-norochotensane[3] in 78% yield. Treatment of the compound[3] with bis-(2-chloroethyl)amine then lead to the 7-bis(2-chloroethyl)carbamyl-norochoteneare[4]. On the other hand the compound[5], which is the 8-methoxynorochotensane, was derived when compound[1] was treated with methanol in a few drops of BF. Treatment of the compound[6], and the compound[7], 7-bis(2-chloroethyl)-carbanyl-8-methoxy-norocheyensane, was then synthesized by reaction of the compound[6] with bis(2-chloroethyl) amine. In the other synthetic pathway when compound[5] was treated with $POCl_3$ in dried benzene, 13-chloro-6-ene-norochetensane[8] with 42% yield was formed. Finally the 13-bis-(2-chloroethyl) amino-8-methoxy-norochotensane[9] was produced when we treated the compound[8] with bis-(2-chloroethyl) amine. In another pathway, reaction between phenolbetaine which is the precursor of the compound[1] and benzoylchloride in dried chloroform gave us the 5,6,7 trihydro-2, 3-methylene-dioxy-9-chloromethyl-10, 11-dimethoxyphenylisoquinoline-8-benzoate[10] in 73% yield. The results of biological activities for these compounds are also presented in Table I and II.

• Research in Plant Disease
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• v.12 no.3
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• pp.221-225
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• 2006

Cucumber mosaic virus(CMV) and Broad bean wilt virus 2(BBWV2) were isolated from Gentiana scabra plants showing typical mosaic and yellowing symptoms. When the inoculum of mosaic symptom propagated in Nicotiana benthamiana was inoculated to primary leaves of Vigna sinensis, the local lesions of different types was developed. Type one produced a small necrotic spot(SNS) of pinpoint type, while the other one showed a large necrotic spot(LNS) of halo type. LNS on primary leaves of V. sinensis was also induced by inoculum from yellowing symptom on G scabra. Single lesion from SNS induced a typical mosaic symptom on N. Benthamiana. On the other hand, LNS produced a chlorotic ring symptom on inoculated leaves and mosaic plus necrotic ringspot on upper leaves of N. benthamiana. An isolate of CMV from SNS and BBWV2 from LNS were detected by using dsRNA analysis, RT-PCR and agar gel double-diffusion test. Thus, our results should provide a tool of a simple method for discrimination from mixed infected plants by CMV and BBWV2.