• Journal of Korean Society of Transportation
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• v.25 no.4
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• pp.21-32
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• 2007

The households to be surveyed are usually huge number at the level of a city or metropolitan survey, not to mention a nationwide travel survey. Therefore, household travel surveys to figure out true origin-destination (O/D) trip patterns (population O/D) are conducted through a sampling method rather than by surveying all of the population in the system. Therefore, the population O/D pattern can only be estimated by expanding the sampled O/D patterns to the population. It is very difficult to avoid the errors involved in the process of sampling, surveying and expanding O/D data. In order to minimize such errors while estimating the true O/D patterns of the population, the validation and adjustment process should employed by doing a comparison between the expanded sample O/D data and observed link traffic volumes. This study suggests a method of validation and adjustment of the expanded sample O/D data by comparing observed link volumes at several screenlines. The study also suggests a practical technique to modify O/D pairs which are excluded in the screenline validation process by comparing observed traffic volume with the results of traffic assignment analysis. An empirical study was also conducted as an example applying the suggested methods of validation and adjustment with Korea's nationwide O/D data and highway network.

• Microbiology and Biotechnology Letters
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• v.26 no.6
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• pp.529-536
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• 1998

In a 20 L fermentor experiments the level of dissolved oxygen (D.O.) strongly affected growth and PHBV production of Azotobacter vinelandii UWD. A higher D.O. (5%) increased specific cell growth rate two folds but PHBV production was 17 folds higher (62.3 wt%) at a lower D.O.(1%) level. D.O. level was not a good criterion to evaluate the effect of aeration on fermentation characteristics of A. vinelandii UWD. This strain maintained an equal D.O. (5%) by decreasing its oxygen consumption rate when oxygen transfer rate (OTR) was decreased by changing agitation speed at a fixed aeration rate. OTR rather than D.O. was a criterion to explain the effect of aeration on the cell growth and PHBV production. At 5% D.O. with a lower 0TR cell growth rate decreased but PHBV production (57.3 wt%) approached to that (62.3 wt%) of the lower (1%) D.O.

• Journal of Korean Society of Transportation
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• v.23 no.1
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• pp.93-102
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• 2005

An Origin-Destination (O/D) is considered as one of the important information in route choices and trip assignments. A household interview survey is deemed to be the traditional and the most widely used method in making sample O/D and its conversion to the total O/D. Some researchers have studied to estimate dynamic O/D from the relationship between link volumes and trip assignment model. Nowadays, owing to the recent rapid spread of cellular phones. Location information of the cellular phone through the Base Station(BS) is considered as an alternative to O/D estimation. In this study, the methodology of generating BS-based O/D and the methodology of converting this O/D into an administrative district-based O/D are proposed. The information of GPS positions and cellular BS positions have acquired by establishing GPS equipment and cellular phone on taxies in Cheongju. Three weeks data are collected and used in estimating O/D by matching them on a digital map. Scatter diagram and sample correlation coefficients are used to investigate the similarity of the GPS-based O/D pattern among weeks, among days, and among times in day. The results show that there are few significant differences among weeks. But there is a difference in O/C pattern between weekday and weekend. Furthermore, there is a difference between morning peak and afternoon peak. Two methodologies are proposed to convert BS-based O/D into an administrative district-based O/D. The first one is to use the distribution pattern of GPS coordinates, the other is to use the coverage area of the BSs. To validate such converted O/D, GPS O/D is used as a true value. The statical analyses through scatter diagram, MAE and RMSE shows that there is few significant defference of pattern between the estimated BS-based O/D and GPS O/D. In the case of using only cellular information, the methodology using coverage area of the BSs is recommended for estimating O/D.

• Journal of Korean Society of Transportation
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• v.19 no.5
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• pp.61-70
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• 2001

The origin and destination(O-D) matrix is one of the most important elements in transportation planning process. Traditionally, transport planners survey the O-D movements in order to estimate the O-D matrix. Even though the cost of the O-D survey requires high amounts of resources, the accuracy is relatively low. Therefore, many researchers have studied the estimation of the O-D matrix for automobile from traffic counts. however, there is a little attention for the application on the transit O-D matrix estimation from traffic counts. The objective of this study is therefore the estimation of the transit O-D matrix from traffic counts using Gradient method. which is verified by the reliability analysis using a contrived small example network.

• Journal of Korean Society of Transportation
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• v.19 no.1
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• pp.77-88
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• 2001

Until now, though most of the studies related to demand estimation method using traffic counts use methods based on singleclass, travel demands or flows are made by mixing various vehicles in real networks. In general, existing demand estimation methods based on traffic counts estimate O/D by converting a multiclass O/D matrix and traffic counts into a singleclass O/D matrix and traffic counts through PCE conversion, and analyze a O/D matrix by dividing into a multiclass O/D matrix and traffic counts after multiplying an estimated O/D matrix by the fixed ratio of a singleclass O/D matrix and traffic counts before PCE conversion. However, the merits of a demand estimation method based on multiclass calculate each route choice ratio about multiclass O/D, and maximize the estimation capability of multiclass by calculating each gradient, the reduction direction of objective function. Therefore, this study aims to establish a demand estimation method which considers congestion between vehicle and vehicle by using multiclass instead of singleclass.

• YAKHAK HOEJI
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• v.54 no.6
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• pp.441-448
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• 2010

In present study, classification and quality control of Genus Polygonatum were developed using the isolated from Polygonati Odorati Rhizoma and Polygonati Rhizoma. 3 components were isolated from Butanol fractions of Polygonati Rhizoma, and 2 components were isolated from Hexane and Butanol fractions of Polygonati Odorati Rhizoma. All the components were obtained using silica gel and ODS column chromatography. The compounds were identified as adenosine, 14-hydroxylfurost-5-ene-3-O-${\beta}$-D-glucopyranosyl-($1{\rightarrow}2$)-O-${\beta}$-D-glucopyranosyl-($1{\rightarrow}4$)-O-${\beta}$-D-galactopyranosyl-26-O-${\beta}$-D-glucopyranoside, 22-O-methyl-14-hydrocxyfurost-5-ene-3-O-${\beta}$-D-glucopyranosyl-($1{\rightarrow}2$)-O-${\beta}$-D-glucopyranosyl-($1{\rightarrow}4$)-O-${\beta}$-Dgalactopyranosyl-26-O-${\beta}$-D-glucopyranoside, ${\beta}$-Sitosteryl-3-O-${\beta}$-D-D-glucopyranoside, 14-hydoxylfurost-5-ene-3-O-${\beta}$-Dglucopyranosyl-($1{\rightarrow}2$)-O-[${\beta}$-D-xylopyranosyl-($1{\rightarrow}3$)]-O-${\beta}$-D-glucopyranosyl-($1{\rightarrow}4$)-O-${\beta}$-D-galactopyranoside through physicochemical data, spectroscopic methods ($^1H$-NMR, $^{13}C$-NMR, Mass) according references. The quality control of genus Polygonatum were conducted using HPLC quantitative analysis of 14-hydroxylfurost-5-ene-3-O-${\beta}$-D-glucopyranosyl-($1{\rightarrow}2$)-O-${\beta}$-D-glucopyranosyl-($1{\beta}4$)-O-${\beta}$-D-galactopyranosyl-26-O-${\beta}$-D-glucopyranoside, 14-hydoxylfurost-5-ene-3-O-${\beta}$-D-glucopyranosyl-($1{\rightarrow}2$)-O-[${\beta}$-D-xylopyranosyl-($1{\rightarrow}3$)]-O-${\beta}$-D-glucopyranosyl-($1{\rightarrow}4$)-O-${\beta}$-D-galactopyranoside in 30 samples collected throughout Korea and China. This method provided a tool for standardization of mix or misusing the commercial Odorati Rhizoma and Polygonati Rhizoma. As a result, contained quantity of 14-hydroxylfurost-5-ene-3-O-${\beta}$-D-glucopyranosyl-($1{\rightarrow}2$)-O-${\beta}$-D-glucopyranosyl-($1{\rightarrow}4$)-O-${\beta}$-D-galactopyranosyl-26-O-${\beta}$-D-glucopyranoside was measured $0.008{\pm}0.006%$ and 14-hydoxylfurost-5-ene-3-O-${\beta}$-D-glucopyranosyl-($1{\rightarrow}2$)-O-[${\beta}$-D-xylopyranosyl-(13)]-O-${\beta}$-D-glucopyranosyl-($1{\rightarrow}4$)-O-${\beta}$-Dgalactopyranoside was measured $0.026{\pm}0.012%$.

• Archives of Pharmacal Research
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• v.22 no.4
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• pp.423-427
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• 1999

A study was carried out to evaluate flavonol glycosides in leaves of Symplocarpus renifolius (Araceae). From the water fraction of the MeOH extract, three new flavonol glycosides were isolated along with three known compounds, Kaempferol-3-O-$\beta$-glucopyranosyl-($1{\rightarrow}2$)-$\beta$-D-glucopyranosyl-7-O-$\beta$-D-glucopyranoside, quercetin-3-O-$\beta$-D-glucopyranosy-1-($1{\rightarrow}2$)-$\beta$-D-glucopyranoside, and caffeic acid. The structures of the new flavonol glycosides were elucidated by chemical and spectral analyses a quercetin-3-O-$\beta$-D-glucopyranosyl-($1{\rightarrow}2$)-$\beta$-D-glucopyranosyl-7-O-$\beta$-D-glucopyranoside, isorhamnetin-3-O-$\beta$-D-glucopyranosyl-(1 2)-$\beta$-D-glucopyranosyl-7-O-$\beta$-D-glucopyranosdie, and quercetin-3-O$\beta$-D-glucopyranosyl-($1{\rightarrow}2$)-$\beta$-D-glycopyranosyl-7-O-($6^{IIII}$-trans-caffeoyl)-$\beta$-D-glucopyranoside.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.2089-2094
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• 2003

The flow around a circular cylinder was controlled by attaching O-rings to reduce drag force acting on the cylinder. Four experimental models were tested in this study; one smooth cylinder of diameter D (D=60mm) and three cylinders fitted with O-rings of diameters d=0.0167D, 0.05D and 0.067D with pitches of PPD=1D, 0.5D and 0.25D. The drag force, mean velocity and turbulent intensity profiles in the near wake behind the cylinders were measured for Reynolds numbers based on the cylinder diameter in the range of $Re_D=7.8{\times}10^3{\sim}1.2{\times}10^5$. At $Re_D=1.2{\times}10^5$, the cylinder fitted with O-rings of d=0.0167D in a pitch interval of 0.25D shows the maximum drag reduction of about 5.4%, compared with the smooth cylinder. The drag reduction effect of O-rings of d=0.067D is not so high. For O-ring circulars, as the Reynolds number increases, the peak location of turbulence intensity shifts downstream and the peak magnitude is decreased. Flow field around the cylinders was visualized using a smoke-wire technique to see the flow structure qualitatively. The size of vortices and vortex formation region formed behind the O-ring cylinders are smaller, compared with the smooth cylinder.

• Bulletin of the Korean Chemical Society
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• v.14 no.2
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• pp.188-191
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• 1993

The reaction between methyl 2,3-di-O-benzyl-4,6-di-O-mesyl-${\alpha}$-D-glucopyranoside (1b) and potassium superoxide resulted in hydrolysis, and gave methyl 2,3-di-O-benzyl-${\alpha}$-D-glucopyranoside (1) as a sole product. When the reaction was performed with a vicinal dimesylate, methyl 4,6-O-benzylidene-2,3-di-O-mesyl-${\alpha}$-D-altropyranoside (4b), again the hydrolysis product, methyl 4,6-O-benzylidene-${\alpha}$-D-altropyranoside (4) was obtained. However, the reaction of potassium superoxide with another vicinal dimesylate, methyl 4,6-O-benzylidene-2,3-di-O-mesyl-${\alpha}$-D-glucopyranoside (3b), nucleophilic displacement took place to afford methyl 4,6-O-benzylidene-${\alpha}$-D-altropyranoside (4). Apparently different results from two trans vicinal dimesylates, 3b and 4b are explained by the transient formation of epoxides, methyl 2,3-anhydro-4,6-O-benzylidene-${\alpha}$-D-allopyranoside (8) and methyl 2,3-anhydro-4,6-O-benzylidene-${\alpha}$-D-mannopyranoside (9) by $KO_2$. The reaction between the allo epoxide 8 and $KO_2$ gave altro 4. The manno epoxide 9 also afforded altro 4 as the major product. Facile epoxide formation by the reaction of a vicinal dimesylate and superoxide was also observed with 3-O-benzyl-1,2-O-isopropylidene-5,6-di-O-mesyl-${\alpha}$-D-glucofuranose: 5,6-anhydro-3-O-benzyl-1,2-O-isopropylidene-${\beta}$-L-idofuranose was obtained.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2005.04a
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• pp.45-45
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• 2005