• Mycobiology
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• v.36 no.2
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• pp.81-87
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• 2008

The optimal conditions for mycelial growth of Phellinus linteus ATCC 26710 were determined to be a log length of 20 cm, temperature of $30^{\circ}C$ and pH of 6.0. Mycelial growth was excellent on the mushroom complete medium, and was optimal when sucrose, man nose and glucose were supplied as carbon sources. Potassium nitrate and sodium nitrate as nitrogen sources supported good mycelial growth. To evaluate P. linteus mycelial colonization on logs, sterilized short log inoculation, drilling inoculation and log-end sandwich inoculation techniques were used. Only sterilized short log inoculation produced good mycelial colonization. Initial mycelial growth and full mycelial colonization were best on 20 cm logs having 42% moisture content. The initial mycelial growth of P. linteus was accelerated over 12hr of sterilization. Basidiocarp formation was optimal using a burying method of logs after $5{\sim}6$ months, and fruiting body formation was superior in cultivation house conditions of $31{\sim}35^{\circ}C$ and in excess of 96% relative humidity.

• Korean Journal of Plant Resources
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• v.11 no.3
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• pp.296-300
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• 1998

When medicinal mushroom, Poria cocos, is cultured , inoculation method of spawn is cross slice inoculation of which the both sides of pine tree were peeled and spawn of P.cocos was inoculated. However, this method required lots of inoculation amount. This study was carried out to improve the culturing method of P. cocos. A good growth of P.cocos was observed in MCM(mushroom complete medium), showing proper mycelia growth and density. In inoculation amount, conventional method(cross slice inoculation) requires 20 bottles of spawn. In contrast, short log method required 8 bottles of spawn and drilling inoculation method 2~3 bottles, which could save by 60% and 85-90% respectively. In the selectrion of tree species, pine and larch had better condition for spawn culture and sclerotia formation condition.In terms of yield , pine was 33.7kg/3.3$m^2$. In the yield of pine, conventional method was 23.4kg/3.3$m^2$, drilling inoculation 29.4kg/3.3$m^2$, short log inoculation 31.7kg/3.3$m^2$, therefore drilling inoculation could increase by 25% and short log inoculation 35%, In addition, management cost was also saved.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.27 no.3
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• pp.180-193
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• 2023

Approximating the implied volatilities and estimating the model parameters are important topics in quantitative finance. This study proposes an approximation formula for short-maturity near-the-money implied volatilities in stochastic volatility models. A general second-order nonlinear PDE for implied volatility is derived in terms of time-to-maturity and log-moneyness from the Feyman-Kac formula. Using regularity conditions and the Taylor expansion, an approximation formula for implied volatility is obtained for short-maturity nearthe-money call options in two stochastic volatility models: Heston model and SABR model. In addition, we proposed a novel numerical method to estimate model parameters. This method reduces the number of model parameters that should be estimated. Generating sample data on log-moneyness, time-to-maturity, and implied volatility, we estimate the model parameters fitting the sample data in the above two models. Our method provides parameter estimates that are close to true values.

• Mycobiology
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• v.30 no.4
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• pp.208-212
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• 2002

For comparison of mycelial colonization of Phellinus linteus on logs, several techniques of inoculation were tested; sterilized short log inoculation, drilling inoculation and log-end sandwich inoculation. The mycelial colonization of P. linteus on logs was good in the treatment of sterilized short log inoculation, but poor in the traditional methods such as drilling inoculation and log-end sandwich inoculation. The initial mycelial growth and the full mycelial colonization of P. linteus in logs were the best in case of 20 cm logs under the condition of 42% moisture content. Also, the initial mycelial growth of P. linteus was accelerated over 12 hours of sterilization. Burying method of logs after $5{\sim}6$ months of incubation was the best for formation of basidiocarps of P. linteus. The formation of fruiting body of P. linteus was quite good in the cultivation house at $31{\sim}35^{\circ}C$ and over 96% of relative humidity.

• Journal of the Korean Data and Information Science Society
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• v.16 no.1
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• pp.157-163
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• 2005

In the Web, the data is generally gathered automatically by Web servers and collected in server or access logs. However, as users access larger and larger amounts of data, query response times to extract information inevitably get slower. A method to resolve this issue is the use of summary tables. In this short note, we design a prototype of summary tables that can efficiently extract information from Web log data. We also present the relative performance of the summary tables against a sampling technique and a method that uses raw data.

• Korean Journal of Food Science and Technology
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• v.52 no.2
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• pp.177-182
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• 2020

This study evaluated the effect of steam heating, gamma irradiation, and ultraviolet (UV) irradiation on microorganism reduction in order to determine an effective sterilization method for red pepper powder. The effect of each treatment on the reduction of thermoduric bacteria and total aerobic bacteria in red pepper powder were as follows: 10 kGy gamma irradiation, reduction of 4 log and 6 log CFU/g, respectively; 12 mW/㎠ UV irradiation (264 nm UV-C), reduction of less than 1 log CFU/g; steam heating at 120℃ for 40 s, reduction of approximately 2 log CFU/g. High-temperature short-time processing at 110℃ for 30 s reduced the total bacterial count in Gochujang solution from 5.70 log CFU/g to 2.26 log CFU/g; at 121℃, the solution was commercially sterile. Steam heating resulted in 1, 2, and 4 log microbial inactivation in garlic, onion, and pepper powder, respectively. Steam sterilization, which consumers prefer over other methods, may be an effective method for reducing microorganisms in spice powders, including those in red pepper powder.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.3
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• pp.329-339
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• 1999

LPXDA(Log-Periodic X Dipole Antenna), consisting of X dipole elements, was proposed as a Log-periodic antenna with short boom length and good Performance relative to LPDA(Log-Periodic Dipole Antenna) . LPXDA for operating frequency band of 500 MHz~l,000 MHz was designed and radiation characteristics of the designed antenna was analyzed by moment method, and compared with LPDA characteristics. The proposed LPXDA, in this paper, was found to have shorter boom length by 20% and better radiation characteristics with variations of frequency relative to the LPDA. The calculated results show good agreement with measurements.

• Agricultural and Biosystems Engineering
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• v.2 no.1
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• pp.15-23
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• 2001

On the assumption that the voices of the cows are produced by the linear prediction filter, we characterized the cows’voices. The order of this filter was determined by examining the voice characteristics both in time and frequency domains. The proposed order of the linear prediction filter is 15 for modeling voice production of the cow. The characteristics of the amplitude envelope of the voice signal was investigated by analyzing the sequence of the short time variance both in time and frequency domains, and the new parameters were defined. One of the coefficients o the linear prediction filter generating the voice signal, the fundamental frequency, the slope of the straight line regressed from the log-log spectra of the short time variance and the coefficients of the linear prediction filter generating the sequence of the short time variance of the voice signal can differentiate the two cows.

• Journal of Sericultural and Entomological Science
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• v.44 no.2
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• pp.74-81
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• 2002

The optimal conditions for mycelial growth of P. linteus ASI 26011 were 25-30$^{\circ}C$ and pH 6.0, respectively. The mycelial growth of P. linteus was excellent on MCM medium. In case of carbon sources, the mycelial growth of P. linteus was best on the culture media that were contained with sucrose, mannose and glucose. Potassium nitrate and sodium nitrate were good for the mycelial growth of P. linteus as a nitrogen source. For comparison of the mycelial colonization of P. linteus on logs, several techniques of inoculation were tested; the sterilized short log inoculation, drilling inoculation and log-end sandwich inoculation. The mycelial colonization of P. linteus on logs was good in the treatment of sterilized short log inoculation, but poor in the traditional methods such as drilling inoculation and log-end sandwich. The initial mycelial growth and the full mycelial colonization of P. linteus were the best on 20 cm logs under the condition of 42% of moisture content in log. Also the initial mycelial growth of P. linteus was accelerated over 12 hours of sterilization. Burying method of logs after 5-6 months of incubation was the best for formation of basidiocarp of P. linteus. The formation of fruiting body of P. linteus was quite good in the cultivation house at the 31-35$^{\circ}C$ and over 96% of relative humidity.

• Journal of Mushroom
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• v.8 no.1
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• pp.16-21
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• 2010

Sparassis crispa(Cauliflower mushroom) was an edible mushroom that shows remarkably high contents of 1.3-${\beta}$-Dglucan compared to other edible mushroom. The mushroom was known to give high antitumor and immunology activated, and then this mushroom was recently cultivated in Japan and Korea. However, cultivation methods ware becoming kept in secret or patents by some companies with complicated procedures. And it was not established cultivation methods of Sparassis crispa up to now. This study was conducted to solve the problem by short-log cultivation method of Sparassis crispa. Some factors effecting on the mycelial growth and primordial formation of Sparassis crispa were investigated. We could produce the mushroom using short-woods of Larix leptolepis, Pinus densiflora, Pinus rigida and Quercus acutissima. We get to high yield fruit-body on short-log cultivaiton of Pinus rigida. And soaking for 8hours in water solution containing 5% uncooked yeast with short-wood of Pinus rigida. The optimal moisture content and temperature were 90~95% and $23{\sim}25^{\circ}C$, respectively.