• Journal of Sensor Science and Technology
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• v.21 no.5
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• pp.367-373
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• 2012

We fabricated a fiber-optic alpha/beta detector, which is composed of a sensing probe, a plastic optical fiber, a photomultiplier tube, and a multichannel analyzer, to obtain the energy spectra of radioactive isotopes. As inorganic scintillators of a sensing probe, a ZnS(Ag) film was coupled with a $CaF_2$(Eu) crystal for alpha and beta spectroscopy. In this study, $^{210}Po$ and $^{90}Sr$ were used as alpha and beta sources, respectively, and we measured the radiation energy spectra using a fiber-optic alpha/beta detector to identify alpha and beta emitting radionuclides for nuclear medicine application. Also, the variations of energy spectrum were obtained according to the length of plastic optical fiber.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.4C
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• pp.395-400
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• 2010

This paper proposes a novel two-stage detection scheme based on combining multiple correlator outputs to enhance the detection performance in ultra-wideband (UWB) signal acquisition. Due to the rich multipath of UWB channels, the signal energy spreads over multiple correlator outputs, which makes each correlator output have only a portion of the signal energy, and thus, degrades the detection performance of the conventional scheme where a single correlator output is used as the decision variable for detection. In the proposed two-stage detection scheme, the decision variable is formed by combining multiple correlator outputs, making it possible to collect the signal energy spread by the multipath. Simulation results show that the proposed scheme can provide a better detection performance over the conventional scheme in various UWB channel environments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.5C
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• pp.479-486
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• 2010

In this paper, we propose a novel low-complexity Alamouti coded orthogonal frequency division multiplexing (OFDM) scheme for asynchronous cooperative communications. Exploiting the combination of OFDM symbols at the source node and simple operations including sign change and complex product at the relay node, the proposed scheme can achieve cooperative diversity gain without use of time-reversion and shifting operations that the conventional scheme proposed by Li and Xia needs. In addition, by using the cyclic prefix (CP) removal and insertion operations at the relay node, the proposed scheme does not suffer from a considerable degradation of bit-error-rate (BER) performance even though perfect timing synchronization is not achieved at the relay node. From the simulation results, it is demonstrated that the BER performance of the proposed scheme is much superior to that of the conventional scheme in the presence of timing synchronization error at the relay node. It is also shown that the proposed scheme obtains two times higher diversity gain compared with the conventional scheme at the cost of half reduction in transmission efficiency.

• Journal of Microbiology and Biotechnology
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• v.24 no.10
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• pp.1319-1326
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• 2014

Rapamycin, produced by the soil bacterium Streptomyces hygroscopicus, has the ability to suppress the immune system and is used as an antifungal, anti-inflammatory, antitumor, and immunosuppressive agent. In an attempt to increase the productivity of rapamycin, mutagenesis of wild-type Streptomyces hygroscopicus was performed using ultraviolet radiation, and the medium composition was optimized using glycerol (which is one of the cheapest starting substrates) by applying Plackett-Burman design and response surface methodology. Plackett-Burman design was used to analyze 14 medium constituents: M100 (maltodextrin), glycerol, soybean meal, soytone, yeast extract, $(NH_4)_2SO_4$, $\small{L}$-lysine, $KH_2PO_4$, $K_2HPO_4$, NaCl, $FeSO_4{cdot}7H_2O$, $CaCO_3$, 2-(N-morpholino) ethanesulfonic acid, and the initial pH level. Glycerol, soytone, yeast extract, and $CaCO_3$ were analyzed to evaluate their effect on rapamycin production. The individual and interaction effects of the four selected variables were determined by Box-Behnken design, suggesting $CaCO_3$, soytone, and yeast extract have negative effects, but glycerol was a positive factor to determine rapamycin productivity. Medium optimization using statistical design resulted in a 45% ($220.7{\pm}5.7mg/l$) increase in rapamycin production for the Streptomyces hygroscopicus mutant, compared with the unoptimized production medium ($151.9{\pm}22.6mg/l$), and nearly 588% compared with wild-type Streptomyces hygroscopicus ($37.5{\pm}2.8mg/l$). The change in pH showed that $CaCO_3$ is a critical and negative factor for rapamycin production.

• Proceedings of the Korean Society of Life Science Conference
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• 2001.06a
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• pp.67-86
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• 2001

A strain producing strongly fibrinolytic enzyme was isolated from soil and was identified to be Bacillus subtilis by biochemical and physiological characterization. The optimal culture conditions for the production of fibrinolytic enzyme was determined to be 1.0% tryptone, 1.5% soluble starch, 0.5% Peptone, 0.5% NaCl, $(NH_{4})_{3}PO_4.3H_{2}O, and MgSO_{4}.7H_{2}O.$ Initial pH and temperature were pH 8.0 and $30^{\circ}C$ , respectively, The highest enzyme production was observed at 30 hours of cultivation at $30^{\circ}C$ The fibrinolytic enzyme was purified to homogeneity by DEAE Sephadex A-50 ion exchange column chromatography, 70% ammonium sulfate precipitation, Sephadex G-200 and G-75 gel filtration column chromatography. The molecular weight of the purified enzyme was 28,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A gene encoding the fibrinolytic enzyme was cloned into a plasmid vector pBluescript, transforming E.coli XL-1 Blue. The clone was able to degrade fibrin, This indicated that the gene could encode a fibrinolytic enzyme. The nucleotide sequence of the 2.7 kb insert was determined in both direction. One open reading frame composed of 1023 nucleotides was found to be a potential protein coding region. There was the putative Shine-Dalgano sequence and TATA box upstream of the open reading frame. The homology search data in the genome database showed that both the 2.7 kb insert and 1 kb open reading frame carried no significance in the nucleotide sequence of known fibrinolytic enzyme from Bacillus serovars. The recombinant cell harboring the novel gene involved in fibrinolysis was subjected to protein purification. The molecular mass of the purified fibrinolytic enzyme was determined to be 31864 Dalton, which was highly in accordance with the molecular mass(33 kDa) of the fibrinolytic gene deduced from the insert. The fibrinolytic enzyme was Purified 50.5 folds to homogeneity in overall yield of 10.7% by DEAE Sephadex A-50 ion exchange, 85% ammonium sulfate precipitation, Sephadex G-50, Superdex 75 HR FPLC gel filtration. In conclusion, a novel fibrinolytic gene from Bacillus subtilis was identified and characterized by cloning a genomic library of Bacillus subtilis into pBleuscript. For the soybean fermented by this strain, it is found that there increased assistant protein about 20% compared to the soybean not fermented and increased about 30% according to amino acid analysis and, in particular, essential amino acid increased about 40%. When keeping this fermented soybean powder at room temperature for about 70days, it showed very high stability maintaining almost perfect activity and, therefore, it gave us great suggestion its possibility of development as a new functional food.

• Convergence Security Journal
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• v.22 no.5
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• pp.69-80
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• 2022

Now that climate change and food resource security are becoming issues around the world, smart farms are emerging as an alternative to solve them. In addition, changes in the production environment in the primary industry are a major concern for people engaged in all primary industries (agriculture, livestock, fishery), and the resulting food shortage problem is an important problem that we all need to solve. In order to solve this problem, in the primary industry, efforts are made to solve the food shortage problem through productivity improvement by introducing smart farms using the 4th industrial revolution such as ICT and BT and IoT big data and artificial intelligence technologies. This is done through the public and private sectors.This paper intends to consider the minimum requirements for the smart farm data collection system for the development and utilization of smart farms, the establishment of a sustainable agricultural management system, the sequential system construction method, and the purposeful, efficient and usable data collection system. In particular, we analyze and improve the problems of the data collection system for building a Korean smart farm standard model, which is facing limitations, based on in-depth investigations in the field of livestock and livestock (pig farming) and analysis of various cases, to establish an efficient and usable big data collection system. The goal is to propose a method for collecting big data.

• Journal of Animal Environmental Science
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• v.18 no.2
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• pp.123-130
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• 2012

This study was conducted to investigate the effects of cattle slurry on productivity of whole crop barley and Italian ryegrass and environmental pollution in paddy land. Cropping systems used in this study were consisted of two designs, such as whole crop barley applied with cattle slurry (WCB) and Italian ryegrass applied with cattle slurry (IRG). The field experiments were conducted on the clay loam at Backsanmyun, Kimje, Chunlabukdo province in Korea for three years (May 2006 to Apr. 2009). This study was arranged in completely randomized design with three replicates. The yields of WCB and IRG were 7,520 kg/ha and 10,320 kg/ha, respectively. The yields of IRG significantly increased as compared with that of WCB (p<0.05). The yield of Italian ryegrass in 1st cutting time was about 2-fold higher than that of 2nd cutting time. The contents of crude protein of IRG were higher than that of WCB. However, the contents of NDF, ADF and TDN were no difference between WCB and IRG treatments. The pH, and contents of T-N, $P_2O_5$ and organic matter (OM) in soil samples collected at the end of the experiment increased as compared with those at the beginning of the experiment (p<0.05). After the end of experiment, the concentrations of CEC (Ca, Na, Mg and K) in soil samples collected at the end of the experiment were remarkably higher than those at the beginning of the experiment (p<0.05). The concentrations of $NH_4$-N, $NO_3$-N, $PO_4$-P, Cl, Ca, K, Mg and Na in leaching water in paddy land cultivated with WCB and IRG were no difference between WCB and IRG treatments.

• The Korean Journal of Zoology
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• v.39 no.1
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• pp.36-46
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• 1996

An endogenous phenoloxidase (EPO) from earthworm, Lumbricus rubellus, has been purified and characterized. The purified EPO using ammonium sulfate fractionation, Blue-2, Phenyl-, and Q-sepharose chromatography steps was revealed in SDS-PAGE as a single protein banri with Mr. of 59 kl)a. A native strudure of the enzyme was examined with an in situ staining of a nondenatudng-PAGE using DL-dopa as a substrate. The result showed that a single band due to the EPO activity was located siighdy above a standard polypeptide with Mr. of 210 kl)a. These fads indicate that the EPO is an oligomeric enzyme. The presence of a monophenolase activity of the purified EPO, which hydroxylates tyrosine to dopa, was confirmed by observing dopachrome accumulation at 475 nm at PH 8.0 with a typical lag phase during 60 mm. of meausrement. A series of inhibition study has been performed for the enzyme with several divalent cation chelators such as phenyithiourea (Flu), 1, lO-phenanthroline, EDTA, and EGTA. Among them, only V'flj inhibited the enzyme with 1C0.5 of 65 MM, which indicated that copper was critical for the catalysis of EPO. The enzyme was maximally active at 35'C and pH 8.0 when L-dopa to dopachrome conversion was spectrophotometricaily monitored at 475 nm. The apparent Km values of P0 for L-opa were obtained as 1.86 mM and 13.8 mM at pH 6.5 and 8.0, respectively. The catalytic efficiencies at both pH were almost identical [(kat/Km)pH8.0/(kcat/Km)pH6.5 = O.92] while the Vmax at p11 8.0 was 6.6-fold higher than that at pH 6.5. This fact may indicate that pH affeds the catalysis at substrate and/or enzyme-substrate complex level rather than the enzyme itself. Taken together, the EPO was an oligomeric enzyme which did not require proteolysis for its activation. These results also indicated that the enzyme can exist, at least, in part as a latent form In vivo, which might be distinct from the prophenoloxidase activating system. Therefore, it is pertinent to consider that there must be certain regulatory molecules or phenomena in L. rubellus which make the 1,0 in a latent form in vivo before the foreign invasions.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.3
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• pp.309-316
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• 2012

This study was performed to investigate the effects of forage cropping system and cattle slurry on productivity of whole crop rice, whole crop barley and Sorghum-Sudangrass hybrid and environmental pollution in paddy land. Forage cropping system used in this study was consisted of double-cropping whole crop barley followed by whole crop rice applied with cattle slurry (DWBRC) and double-cropping whole crop barley followed by Sorghum-Sudangrass hybrid applied with cattle slurry (DSSBC). The field experiments were conducted on the clay loam at Backsanmyun, Kimje, Chunlabukdo province in Korea for three years (May 2006 to Apr. 2009). This study was arranged in completely randomized design with three replicates. The field had been sown with whole crop rice 'Nampyung', Sorghum-Sudangrass hybrid 'Sordan79' and whole crop barley 'Younyang'. The yields of whole crop barley in DWBRC and DSSBC were 7,515 kg/ha and 8,515 kg/ha, respectively. The yields of whole crop barley in DSSBC significantly increased as compared with that of DWBRC (p<0.05). The contents of crude protein, neutral detergent fiber (NDF), acid detergent fiber (ADF), total digestible nutrient (TDN) of whole crop barley in DWBRC were not difference as compared with those of DSSBC. The pH, and contents of total nitrogen and organic matter in soil samples collected at the end of the experiment increased as compared with those at the beginning of the experiment (p<0.05). However, The content of phosphate in DWBRC was no difference as compared with DSSBC. In addition, after the end of experiment, the concentrations of exchangeable cations (Ca, Na, Mg and K) in soil samples collected at the end of the experiment were remarkably higher than those at the beginning of the experiment (p<0.05). The concentrations of $NH_4$-N, $NO_3$-N, $PO_4$-P, Cl, Ca, K, Mg and Na in leaching water were hardly influenced by the cropping system and application of cattle slurry.