• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.384-387
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• 2000

Heteropolysaccharide-7 (PS-7) was produced by Beijerinckia indica HS-2001 under aerobic condition. Production of PS-7 was investigated under various ratios of glucose as carbon source to ammonium nitrate as nitrogen source. Maximal production of PS-7 was 7.13 g/l when concentrations of glucose and ammonium nitrate were 10 g/l and 0.3 g/l, respectively. But its conversion rate from glucose was as low as 7 %. The highest conversion rate of PS-7 was 46% when those of glucose and ammonium nitrate were 1.0 g/l and 0.3 g/l, respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.11C
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• pp.1030-1036
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• 2006

In this paper, we present two methods of correcting bit errors in constant amplitude multi-code (CAMC) CDMA, which uses the redundant bits only. The first method is a parity-based bit correction with hard-decision, where the received signals despread into n two-dimensional structure with both horizontal parity and vertical parity. Then, an erroneous bit is corrected for each $4{\times}4$ pattern. The second method is a turbo decoding, which is modified from the decoding of a single parity check product code (SPCPC). Experimental results show that, in the second method, the redundant bits in CAMC can be fully used for the error correction and so they are not really a loss of channel bandwidth. Hence, CAMC provides both a low peak-to-average power ratio and robustness to bit errors.

• Korean Journal of Organic Agriculture
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• v.25 no.4
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• pp.749-758
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• 2017

This Research was the standardization of nutrient sources by reviewing the possibility of cultivation and analysis of imported nutrient sources used in Pleurotus ostreatus culture. As a first result, the concentration of heavy metals was not detected or trace, and the total nitrogen content of cotton seed pomace was 6.22% in Australia, which was higher than that of Chinese or USA. As a second result of physical properties of nutrient sources, the water holding capacity of beet pulp from Egypt was higher with increasing pressure. The volume water content of US was highest at 400hpa and 500hpa in case of cottonseed meal. Third, the content of total nitrogen was the highest at pH 5.51 and the total nitrogen content was the highest at 2.45, and the C/N ratio was the highest at 28.18. Last result shows that first germination day, yield and biological effciency of all treatments were not significant differnet except T2. These results shows that australian cootton was inappropriate to Pleurotus ostreatus culture. Nevertheless, the safety and standardization of the Pleurotus ostreatus culture medium should be assured by reviewing the media low material importing season, mushroom yield and nutrient sources.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1649-1651
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• 2002

Ultra-wide bandwidth (UWB) detection method has been widely used as a front end detection scheme for the ultra-high frequency (UHF) partial discharge (PD) monitoring systems. A broad-band video detector module was developed and characterized for the UHF UWB PD detection systems. The useable bandwidth of the module is more than 2 GHz and it is optimized for 50-ohm systems. The detection sensitivity and dynamic range of the module were characterized by using a known ns-width RF pulses of GHz range. The dynamic range is more than 6-decades and the module can detect pulsed RF signals down to 1 nW. The detector module can eliminate expensive equipment such as high speed oscilloscopes and radio frequency (RF) spectrum analyzers. Therefore, it enables one to use slow speed data acquisition systems for the PD monitoring at the UHF range. The detector module was used to detect real PDs of about <3 pC. The module converts the UWB PD signals into a low-bandwidth video signal with a high signal-to-noise ratio.

• Journal of Communications and Networks
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• v.17 no.5
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• pp.491-498
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• 2015

Recognition of radar emitter signals is one of core elements in radar reconnaissance systems. A novel method based on singular value decomposition (SVD) and the main ridge slice of ambiguity function (AF) is presented for attaining a higher correct recognition rate of radar emitter signals in case of low signal-to-noise ratio. This method calculates the AF of the sorted signal and ascertains the main ridge slice envelope. To improve the recognition performance, SVD is employed to eliminate the influence of noise on the main ridge slice envelope. The rotation angle and symmetric Holder coefficients of the main ridge slice envelope are extracted as the elements of the feature vector. And kernel fuzzy c-means clustering is adopted to analyze the feature vector and classify different types of radar signals. Simulation results indicate that the feature vector extracted by the proposed method has satisfactory aggregation within class, separability between classes, and stability. Compared to existing methods, the proposed feature recognition method can achieve a higher correct recognition rate.

• Journal of the Korean Society of Safety
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• v.8 no.1
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• pp.29-34
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• 1993

Two major hazardous gases. SOx and NOx. are emissioned from fossile fuels. SOx has been removed when oil is refined but NOx hasn't. So NOx is very serious problem in air pollution now There are several technologies to remove NOx. e.g. cooling method. scrubbers method. combustion method, polymer membrane method and adsorbent methods. Polymer membrane and adsorbent methods have good economic merit in removal systems of low content hazard gases. Traditional absorbents are porous silicas, aluminas. active carbon and zeolites. But these absorbents act only physisorption which has less removal performance than chemisorption. In this study. polymeric absorbent which has chemisorption as well as physisorption was analyzed about chemical structure and experimented about optimum operation conditions. The results showed that the chemical structure of the polymeric absorbent was expected as polystyrene having -N-CH$_2$COOH absorbent was revealed about 310$m^2$/g. The molar ratio of absored NO to charged NO in absorption experiments was shown 60% of the polymeric absorbent and 45% of zeolite absorbent at 3$0^{\circ}C$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.10
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• pp.775-778
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• 2011

TBP (tertiarybutylphosphine), a relatively new material for phosphorus, has been studied with EDMIn (ethyldimethylindium) as an indium source for the growth of InP by MOVPE (metalorganic vapor phase epitaxy). Mirror smooth and good crystalline InP layers were obtained at $500-600^{\circ}C$ with the TBP/EDMIn molar ratio as low as 21. The deposited InP layers are all n-type with the electron concentration in the range of (5-10)${\times}10^{16}\;cm^{-3}$, which is a lot higher than those from $PH_3$. This high concentration is due presumably to the high concentration of donor impurities in TBP. And it has been found that the formation of adduct occurs between EDMIn and TBP at room temperature when the partial pressure of EDMIn in the reactant mixture is above $1{\times}10^{-2}$ Torr. The high concentration of impurities in TBP and the adduct formation between EDMIn and TBP are major obstacles in replacing $PH_3$ and TMIn for the growth of device quality InP layers.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.3
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• pp.442-447
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• 2011

Co-incorporation of Leguminosae with Gramineae could reduce the risk of nitrogen starvation phenomena caused by appling green manure of Gramineae alone. The objective of the study was to examine the effect of mixed sowing of hairy vetch and rye seeds on soil quality in mountainous highland. Mixed sowing of hairy vetch and rye increased the yield of green manure and nutrients compared with those for sowing of hairy vetch or rye alone. The yield of green manure from row seeding was $5.3Mg\;ha^{-1}$ compared with $4.8Mg\;ha^{-1}$ for broadcast seeding. Incorporation of the two green manure crops increased yield of red-bean by 58~92% as compared with yield for incorporation of rye alone. The results obtained in the study imply that mixed sowing of hairy vetch and rye can solve the problem of low emergence of hairy vetch in spring and high C/N ratio and rough incorporation of rye, in addition to increase in yield of green manure.

• Journal of Positioning, Navigation, and Timing
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• v.13 no.3
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• pp.245-256
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• 2024

Following the introduction of civilian navigation, the commercial Global Navigation Satellite System (GNSS) receivers' market has been expanding in various fields such as autonomous driving and smart cities. With improved receiver performance and widespread use of GNSS, the configurations of base and rover receivers are becoming more complex. As a result, user must consider combinations of base stations with different qualities, costs, and performances. To address these issues, we conducted zero-baseline tests to analyze the double-differenced code-pseudorange noise of various receiver combinations, ranging from low- to high-cost. The results showed that the noise varied depending on the receiver combination. Notably, receivers from the same manufacturer exhibited similar noise and positioning errors despite significant price differences. We also found that the double-differenced noise of all receiver combinations was correlated with the Carrier-to-Noise Density Ratio (C/N0), the satellite elevation angle, and the Doppler shift, and it did not perfectly follow a normal distribution. Further analysis based on Modified Allan Deviation (MDEV) showed that different types of noise were observed for each receiver combination and the double-differenced noise and positioning errors have similar statistical characteristics. From this study, the importance of receiver combinations and their various characteristics can be better understood.

• Korean Journal of Agricultural Science
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• v.41 no.3
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• pp.213-220
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• 2014

This study was conducted to evaluate the effects of high n-3 or n-6 diet on free fatty acid profile and meat quality traits of pork loin. The 20 heads of commercial $Landrace{\times}Yorkshire{\times}Duroc(LYD)$ crossbreed pigs ($90.9{\pm}2.4BWkg$) were divided into four groups by added fat and oils, such as 5% tallow (Control), 5% linseed oil (T1), 5% safflower oil (T2), and mixture of linseed oil (2.5%) + safflower oil (2.5%) (T3), then reared 4 weeks. Pork loins were taken after slaughter, then sliced in 2 cm thickness and put in low-density polyethylene (LDPE) bag for analysis. T1 showed significantly high concentration of linolenic acid ($2.35{\pm}0.21%$) (p<0.05). The total amount of saturated fatty acids (SFA), mono-unsaturated fatty acids (MUFA) and poly-unsaturated fatty acid (PUFA) was significantly high in T1 ($36.05{\pm}1.18%$), C ($22.60{\pm}2.11%$) and T2 ($47.80{\pm}1.29%$), respectively (p<0.05). However, the ratio of n-6:n-3 was significantly low in T1 ($11.57{\pm}0.90$) than that of T2 ($37.56{\pm}12.51$) (p<0.05). There was no signigicant difference in lightness, redness, pH, water holding capacity and cooking loss between treatments (p>0.05). However, the yellowness of T2 was significantly higher than others (p<0.05). From those results, it was considered that feeding high n-3 and n-6 fatty acid diet to pig enables modify fatty acid profile of pork without any side effect on meat quality.