• Biotechnology and Bioprocess Engineering:BBE
• /
• v.11 no.2
• /
• pp.121-126
• /
• 2006

Saikosaponin productivity was examined in a Bupleurum falcatum L. BFHR2 hairy root culture in response to changes in the sucrose content $(2{\sim}8%)$, nitrogen content $(0{\sim}250mM\;NH_4NO_3)$, phosphate content $(0{\sim}12mM\;NaH_2PO_4)$, and the potassium content $(0{\sim}87.2 mM\; KCl)$ of the culture media. We found that the conditions for maximal saikosaponin production differed from those for optimal root growth. Highest saikosaponin yield was achieved for 8% sucrose, 62mM $NH_4NO_3$ 1.2 mM $NaH_2PO_4$, and 0.5mM KCl.

• Proceedings of the Korean Information Science Society Conference
• /
• 1998.10c
• /
• pp.467-468
• /
• 1998

Impulsive noise appears as black and/or white spots in an image. It is usually caused by errors during the image acquisition or transmission through communication channels. This paper presents a study on the impulsive noise reduction filter of digital image. A much more effective method for removing impulse noise is weighted median filtering. But it loses some information by changing center value with no condition. We propose some new technique to change center value with some conditions. In this paper, the performance of conditional weighted median filter is compared to the commonly used median filter, mean filter, max/min filter, and weighted median filter. A quantitative comparison is performed on MSE (Mean Square Error), RMSE (Root Mean Square Error), and SNR (Signal to Noise Ratio). Proposed conditional weighted median filter can yield better performance than regular filters.

• Journal of Conservation Science
• /
• v.4 no.1 s.4
• /
• pp.53-58
• /
• 1995

In order to establish the procedures for investigating environmental influences to wooden cultural property, existing study data were surveyed and necessary steps for performing the investigation works were presented to be applied for the future works in this country. Environmental factors which influence to the conservation of wooden cultural property should first be studied for items concerned with their damage situations. On basis of these data, laboratory works to yield the standard value for each factor should be conducted by means of testing samples exposed under laboratory simulated environmental conditions. Outdoor measurements may be followed for samples exposed to the open air at the site of that property. These data may be compared with those of laboratory standard value and overall evaluation for the factor influencing mostly tn the damage status of that property may further be conducted. Referring data obtained in this investigation, necessary measures to be taken for conserving that property may be able to be established.

• Journal of Microbiology and Biotechnology
• /
• v.1 no.2
• /
• pp.111-115
• /
• 1991

The green alga, Dunaliella salina under fed-batch cultivation produced 51.12 mg of hydrocarbon per liter with maintaining 0.313 (g dry wt/l). About 20% of hydrocarbon production yield based on dry biomass was obtained from both batch and fed-batch processes. Optimum culture conditions of light intensity, pH and salt concentration were obtained as 0.0080 (kJ/$cm^2$/h), 8.0 and 1.4 (g of NaCl/l), respectively by response surface analysis. The production of hydrocarbons in D. salina was closely correlated to cell growth. Fed-batch cultivation produced more hydrocarbons and maintained better cell growth than a batch process.

• Journal of Microbiology and Biotechnology
• /
• v.17 no.9
• /
• pp.1550-1553
• /
• 2007

The functional characteristics of a ${\beta}$-cyclodextrin glucanotransferase (CGTase) excreted from alkalophilic Bacillus sp. BL-31 that is highly specific for the intermolecular transglycosylation of bioflavonoids were investigated. The new ${\beta}$-CGTase showed high specificities for glycosyl acceptor bioflavonoids, including naringin, rutin, and hesperidin, and especially naringin. The transglycosylation of naringin into glycosyl naringin was then carried out under the conditions of 80 units of CGTase per gram of maltodextrin, 5 g/l of naringin, 25 g/l of maltodextrin, and 1 mM $Mn^{2+}$ ion at $40^{\circ}C$ for 6 h, resulting in a high conversion yield of 92.1%.

• Microbiology and Biotechnology Letters
• /
• v.22 no.6
• /
• pp.672-678
• /
• 1994

For production of vanillic acid from vanillin, optimum culture conditions for Pseudomo- nas sp. GD-088, having vanillin-oxidizing activity were investigated. The highest vanillin-oxidizing activity was obtained when this strain was cultured at 30$\circ$C for 24 hr in a medium consisting of 3.0 g/l xylose and 0.46 g/l NH$_{4}$CI (pH 7.0). When 18 g/l of whole Pseudomonas sp. GD-088 cells as the enzyme source was used in 50 mM phosphate buffer (pH 7.0) containing 3.0 g/l of vanillin, 2.463 g/l of vanillic acid was produced for 40 minutes. This amount of vanillic acid corresponds to a 90% yield, based on vanillin.

• Journal of Korean Society for Quality Management
• /
• v.7 no.2
• /
• pp.22-28
• /
• 1979

The problem considered in this paper is to select the vital factor effect to the product quality through the experimental design and analysis of response surface, so as to control the quality improvement of industrial product. In this time, even through the mathematical model is unknown it could be applicable to control the quality of industrial products and to determine optimum operating condition for many technical fields, particulary, for industrial manufacturing process. When a set of data is available from an experimental design, it is often of interest 1:0 fit polynominal repression model in independent variables (eg, time, temperature, pressure, etc) the optimize the response variable (eg. yield, strength etc). This paper proposes a method known to obtain the optimum operating condition, and how to find the condition by using table of orthogonal array experiments, and optimization methodology of statistical model. A criterion can be applied determining to optimum operating conditions in manufacturing industry and improving the fit of response surface which may be used for prediction of responses and quality control of industrial products.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2002.02a
• /
• pp.144-147
• /
• 2002

In this study, springback analysis of side rear member is carried out. Side rear member is one of the parts which shows severe springback problems. Forming, trimming, flanging and springback stages can be analyzed successively. From forming analysis, we identified the possible spots in which tearing may occur and can prevent failure. In springback analysis we used the boundary conditions same as applied to the blank on the checker so that the computational result can be compared with experimental one. Form .the comparison, springback analysis can yield relatively good results in a qualitative sense. However, in order to get good deformation result quantitatively, there still remains unsettled tasks in the forming analysis with very small die radius. It is found that we have to develop the element with better bending characteristics and precise contact treatment.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1996.11a
• /
• pp.1044-1047
• /
• 1996

This paper presents durability characteristics of electrorheological(ER) fluids which undergo a reversible phase change depending upon the imposition of electric fields. The field-dependent Bingham properties are subjected to be altered from long time use of the ER fluid. The level of the changed properties depends upon employed device and test conditions. A piston-rod system which has same mechanism as ER dampers is adopted in this study and tested by increasing operation cycle up to 1 million. Bingham properties of initial and us ER fluids are tested and compared. In addition, these ER fluids are applied to ER damper in order to evaluate damping force performance.

• Journal of the Korean Wood Science and Technology
• /
• v.18 no.4
• /
• pp.79-85
• /
• 1990

Many kinds of acetosolv lignin including ricestraw and spruce lignin were pyrolyzed. and liquefied in the autoclave reactor using 50% tetralin and m-cresol solution respectively as soluble solvent and Co-Mo as catalyst. In order to promote deoxyhydrogenolysis reaction $H_2$ gas was supplied into the reactor. The ratio between lignin and the soluble solvent are lg and 10cc. The reaction conditions are $200^{\circ}-700^{\circ}C$ of reaction temperature, 10-50 atms of reaction pressure and 100-500rpm of the reactor stirrer. By the deoxyhydrogenolysis liquefaction reaction, the main chemical structures of lignin which are aryl-alkyl-${\beta}$-0-4 ether, phenylcoumaran and biphenyl etc. are easily destroyed into liqufied aromatic compounds and aliphatic compunds linked with aromatic compounds. The percent yield of monomeric phenols on the weight bvase of lignin reacted reached to 12-14% by the chemical analytic GC-MS etc.