• Honam Mathematical Journal
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• v.33 no.2
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• pp.247-259
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• 2011

In this paper, the $(\frac{G'}{G})$-expansion method is used to construct new exact travelling wave solutions of some nonlinear evolution equations. The travelling wave solutions in general form are expressed by the hyperbolic functions, the trigonometric functions and the rational functions, as a result many previously known solitary waves are recovered as special cases. The $(\frac{G'}{G})$-expansion method is direct, concise, and effective, and can be applied to man other nonlinear evolution equations arising in mathematical physics.

• Korean journal of food and cookery science
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• v.7 no.3
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• pp.69-76
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• 1991

Recent epidemiological observations suggested beneficial effects of dietary fiber on man's health. The obsective of this study was to obtain the dietary fiber reference data of mushrooms. The dietary fiber contents of six different mushrooms (Cornellus edodes, Auricularia auriculajudae, Gyrophora esculanta, Agaricus bisporus, Pleurotus ostreatus, Collybia velutipes) were analyzed by Southgate method, modified neutral detergent fiber (NDF) method and Food Research Institute (FRI) method. Duplicate sample were used for each determination. The mean values of total dietary fiber by Southgate method, modified NDF method and FRI method were respectively $20.08\pm1.45g$/100g dry weight, $20.24\pm1.85g$/100g dry weight and $21.5\pm2.70g$/100g dry weight. The mean values of all mushroom samples by FRI method were significantly different from the mean values of the samples by modified NDF method and Southgate method. However, there was no difference in the mean values of the samples between modified NDF method and Southgate method. By Southgate method, total dietary fiber of mushrooms composed of 1.7-3.1% soluble fiber, 47.0-66.6% hemicellulose, 28.4-57.7% cellulose and 0.9-3.3% lignin. By modified NDF method, total dietary fiber of mushrooms composed of 61.8-79.1% hemicellulose, 5.4-32.9% cellulose and 4.5- l5.5% lignin. Therefore, dietary fiber contents of mushrooms were mainly hemicellulose. Our values for total dietary fiber for six mushrooms were 2~4 times higher than crude fiber in textbook.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.8
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• pp.1075-1079
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• 2014

In this paper, we describe the analysis and the compensation method of the g-sensitivity error for MEMS vibratory gyroscopes. Usually, the g-sensitivity error has been ignored in the commercial MEMS gyroscope, but it deserves our attention to apply for the missile application as a tactical grade performance. Thus, it is necessary to compensate for the g-sensitivity error to reach a tactical grade performance. Generally, the g-sensitivity error seems intuitively to be a gyroscope bias error proportional to the linear acceleration. However, we assert that the g-sensitivity error mainly causes not a bias error but a scale-factor error. And we verify that the g-sensitivity scale-factor error occurs due to the non-linearity of parallel plate electrodes. Therefore, we propose the compensation method to remove the g-sensitivity scale-factor error. The experimental result showed that a proposed compensation method improved successfully the performance of the MEMS vibratory gyroscope.

• Journal of Food Hygiene and Safety
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• v.10 no.4
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• pp.225.2-262
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• 1995

Ochratoxin A was produced from Aspergillus ochraceus ATCC 18472 which was then orally administered into the experimental mice to study the toxic levels of ochratoxin A. AELISA (enzyme-linked immunosorbent assay) method which is more rapid and safe than conventional analytical method, was developed by using ochratoxin A antibody. This method was successfully used to measure the levels of ochratoxin Ain blood, liver and kidney of mice. In order to produce a large amount of ochratoxin A to study toxicity in the mice, Aspergillus ochraceus ATCC 18412 was incubated in the rice medium and as a result 0.5 g of ochratoxin A form rice medium (kg) was produced after extraction and purification Feed consumption and gain in body weight of mice with ochratoxin A at a level of $10 \mu\textrm{g}/g$ body weight was significantly (p<0.05) reduced as compared with control during period of 3 weeks. Ochratoxin A-BSA conjugate was made by putting 13 mole of ochratoxin A on I mole of BSA. This conjugate was used to develop ELISA method. The minmum detection level of ochratoxin A by established ELISA method was 0.5 ppb. After oral adminstraton of ochratoxin A dose of $10\;\mu\textrm{g}/g$ every two day for 3 weeks, concentration of ochratoxin A was measured in the blood, liver and kidney by ELISA method. The level of ochratoxin A was $11\;\mu\textrm{g}/dl,\;0.9 \mu\textrm{g}/g\;and\;3.7\;\mu\textrm{g}/g$ in the blood, liver and kidney, respectively.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1987.04a
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• pp.184-187
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• 1987

The method of Conjugate Gradient(C.G.M) is applied to the solution of current distribution from body of revolution (B.O.R).Using the C.G.M it is possible to analyze electrically large arbtrarily oriented B.O.R. The fundamental differences between C.G.M and moment method are outlined. This method converges for any initial guess and this techniqe gurantees a monotonic convergence. Numerical results are presented for electromagnetic case which show good agreement with moment solution.

• Journal of applied mathematics & informatics
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• v.35 no.3_4
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• pp.399-411
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• 2017

We first provide the linear operator equations corresponding to the Tikhonov regularization image denoising problems with different regularization terms, and then we propose how to choose Kronecker product preconditioners which are required for accelerating the $G{\ell}$-PCG method. Next, we provide how to apply the $G{\ell}$-PCG method with Kronecker product preconditioner to the linear operator equations. Lastly, we provide numerical experiments for image denoisng problems to evaluate the effectiveness of the $G{\ell}$-PCG with Kronecker product preconditioner.

• Analytical Science and Technology
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• v.14 no.2
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• pp.95-102
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• 2001

A comprehensive analytical method of endocrine disruptors[i.e., nonylphenol(NP), octylphenol(OP), bis(2-ethylhexyl) phthalate(BEHP)] in meat or pork samples was developed. The method employed closed culture tube extraction with dichloromethane and solvent exchange to iso-hexane and SPE(2g) aminopropyl column, followed by determination on gas chromatography linked to mass spectrometry(GC/MS) operated in the single ion monitering(SIM) mode. For the multipoint recovery of nonylphenol, octylphenol and bis(2-ethlhexyl) phthalate OP, NP were showen good recoveries in $0.125-1.25{\mu}g/g$ range of concentration, and BEHP more good recoveries in $0.0125-12.5{\mu}g/g$ wide range of concentration. The present method was applied to beef or pork samples of mart and butcher in Cheonju city and near Cheonju. The range of concentrations was respectively, $0.06-0.24{\mu}g/g$ in nonylphenol(NP) and $0.36-2.35{\mu}g/g$ in bis(2-ethylhexyl) phthalate(BEHP), but octylphenol(OP) was not dected in any samples. This method provides a powerful analytical tool to investigate a wide range of endocrine disruptors in biological samples of limited quantity.

• Journal of applied mathematics & informatics
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• v.29 no.1_2
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• pp.351-367
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• 2011

In this article, we construct exact traveling wave solutions for nonlinear PDEs in mathematical physics via the (1+1)- dimensional combined Korteweg- de Vries and modified Korteweg- de Vries (KdV-mKdV) equation, the (1+1)- dimensional compouned Korteweg- de Vries Burgers (KdVB) equation, the (2+1)- dimensional cubic Klien- Gordon (cKG) equation, the Generalized Zakharov- Kuznetsov- Bonjanmin- Bona Mahony (GZK-BBM) equation and the modified Korteweg- de Vries - Zakharov- Kuznetsov (mKdV-ZK) equation, by using the (($\frac{G'}{G}$) -expansion method combined with the Riccati equation, where G = $G({\xi})$ satisfies the Riccati equation $G'({\xi})=A+BG^2$ and A, B are arbitrary constants.

• Journal of Food Hygiene and Safety
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• v.6 no.3
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• pp.139-145
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• 1991

In order to observe the Na contents, Korean common foods, especially processed foods were analyzed by Atomic Absorption Spectrophotometer. 1. The Na contents of instant noodle (ramen) was 400-900 mg/100 g and Na contents of their soup powder was 10000-16000 mg/100 g. 2. The Na contents of corns and beans was very low but their processed foods, com Dake and soybean milk, had relatively high Na contents. 3. The Na contents of meats was 40-60 mg/100 g but the Na contents of meats products was 700-900 mg/100 g. 4. The Na contents of Davoring salt was 12000-38000 mg/100 g, those of soybean products was 3000-6OOO mg/100 g, and that of seasoning MSG was 8000-17000 mg/100 g. 5. There was no statistical difference between the results of wet ash method and dry ash method in the Na contents of all food groups.

• Journal of odor and indoor environment
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• v.17 no.4
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• pp.362-371
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• 2018

Indoor Volatile organic compounds (VOCs) are classified as known or possible toxicants and odorants. This study characterized VOC levels in 11 homes in an area in the capital of Seoul by using two different methods of VOCs sampling, which are the active sampling using a thermal sorption tube and the passive sampling using a diffusion sampler. When using the active sampling method, the total target VOC concentration ranged from 41.7 to $420.7{\mu}g/m^3$ (mean $230.4{\mu}g/m^3$ ; median $221.8{\mu}g/m^3$) during winter and 21.3 to $1,431.9{\mu}g/m^3$ (mean $340.1{\mu}g/m^3$; median $175.4{\mu}g/m^3$) during summer. When using the passive method, 29.6 to $257.5{\mu}g/m^3$ (mean $81.8{\mu}g/m^3$; median $49.4{\mu}g/m^3$) during winter and 1.2 to $5,131.1{\mu}g/m^3$ (mean $1,758.8{\mu}g/m^3$; median $1,375.1{\mu}g/m^3$) during summer. Forty-nine VOCs were quantified and toluene showed the highest concentration regardless of the season and the sampling method studied. The distribution of VOCs was relatively varied by using the active method. However, it showed a low correlation with indoor environmental factors such as room temperature, humidity and ventilation time. The correlation between indoor environmental factors and VOCs were relatively high in the passive method. In particular, these characteristics were confirmed by principal component analysis.