• Journal of Korean Society of Transportation
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• v.28 no.5
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• pp.141-153
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• 2010

The study is about the development of operating speed prediction models aimed for an evaluation of design consistency of four lane rural roads. The main differences of this study relative to previous research are the method of data collection and classification of road alignments. The previous studies collected speed data at several points in the horizontal curve and approaching tangent. This method of collection is based on the assumption that acceleration and deceleration only occurs at horizontal tangents and the speed is kept constant at horizontal curves. However, this assumption leads to an unreliable speed estimation, so drivers' behavior is not well represented. Contrary to the previous approach, speed data were collected with one and data analysis using a speed profile is made for data selection before building final models. A total of six speed prediction models were made according to the combination of horizontal and vertical alignments. The study predicts that the speed data analysis and selection for model building employed in this study can improve the prediction accuracy of models and be useful to analyze drivers' speed behavior in a more detailed way. Furthermore, it is expected that the operating speed prediction models can help complement the current design-speed-based guidelines, so more benefits to drivers as real road users, rather than engineers or decision makers, can be achieved.

• Korean Journal of Food Science and Technology
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• v.40 no.2
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• pp.184-189
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• 2008

Effects of sucrose at different concentrations (0, 10, 20, and 30%, w/w) on steady and dynamic shear rheological properties of sweet potato starch (SPS) paste (5%, w/w) were investigated. The steady shear rheological properties of SPS-sucrose composites were determined from rheological parameters based on power law and Casson flow models. At 25$^{\circ}C$ all the samples showed pseudoplastic and thixoropic behavior with high yield stress. Consistence index (K), apparent viscosity (${\eta}_{a,100}$), and yield stress (${\sigma}_{oc}$) values of SPS-sucrose composites decreased with increasing sucrose concentration from 10% to 30%. The decrease of swelling power was observed at higher sucrose concentration (>20%) and the low swelling power yielded a lower K, ${\eta}_{a,100}$, and ${\sigma}_{oc}$ values. In temperature range of 25-70$^{\circ}C$, Arrhenius equation adequately assessed variation with temperature. Oscillatory test data showed weak gel-like behavior. Magnitudes of storage (G') and loss (G") moduli increased with an increase in sucrose concentration and frequency. The SPS-sucrose composite at 30% concentration closely followed the Cox-Merz superposition rule.

• Korean Journal of Head & Neck Oncology
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• v.12 no.2
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• pp.153-160
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• 1996

Regardless of the prognostic factors in papillary thyroid cancer, such as sex, age, size of tumor, extent of disease, and distant metastasis, the prognosis of papillary thyroid cancer is sometimes difficult to predict from clinical and microscopic analysis alone and additional prognostic indicators are needed. Recent studies of thyroid cancer have indicated that DNA aneuploidy may be correlated to the biological behavior of malignancy and inversely correlated to the prognosis, but it still remains contraversal. We performed this study to assess DNA ploidy patterns in relation with the previously known prognostic factors in AMES scoring system and lateral neck node metastasis in papillary thyroid cancer. A series of 132 patients with papillary thyroid cancer and 80 patients with benign thyroid tumor(27 follicular adenomas and 53 adenomatous goiters) as a control group from October 1993 to Feburary 1995 were analyzed and their nuclear DNA content was measured with flow cytometry using fresh tissue specimens. DNA aneuploidy was found in 8(6.1%) in papillary cancer and 8(10%) in benign tumor. S-phase traction(SFP) and proliferative index(PI) were higher in thyroid cancers, being 2.18$\pm$4.24%, 6.34$\pm$4.94% in the papillary thyroid cancers and 1.97$\pm$2.93%, 4.44$\pm$3.80% in the benign tumors, respectively. However there was no significant difference of values between two groups(p>0.05). Among variable prognostic factors studied(age, sex, size of tun or, extent of disease, distant metastasis in AMES scoring system and lateral neck node metastasis), DNA aneuploidy was found to be common in distant metastasis(p<0.001) and in lateral neck node metastasis(p>0.035), but there was no significant difference between the high risk and low risk group according to the AMES scoring system(p<0.08). In our study, DNA aneuploidy was not valuable in determining the presence of malignancy and did not correlate to the AMES scoring system. However, follow-up study of more cases will be needed for accurate information about the DNA ploidy as a independent prognostic factor.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.5
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• pp.722-726
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• 1996

To bring out the functional properties of Agar-agar extracted with 0.01N $H_2SO_4$ from Cellidium amansii produced in Che-ju Udo and its rheological properties were investigated. The flow behavior indexes in the range of $0.5\~5\%$ agar-agar solution were $0.62\~0.69\;at\;80^{\circ}C,\;0.46\~0.67\;at\;60^{\circ}C\;and\;0.34\~0.64\;at\;50^{\circ}C$. The consistency indexes were $0.12\~1.26\;Pa{\cdot}s^n\;at\;80^{\circ}C,\;0.12\~7.28\;Pa{\cdot}s^n\;at\;60^{\circ}C\;and\;3.9\~19952.6\;Pa{\cdot}s^n\;at\;50^{\circ}C$. Consistenry index's existence nature to concentration is two straight line relation which have different slopes on the border of $2\%$ concentration of agar-agar solution and existence nature of temperature followed Arrhenius equation. And the activation energy, in the range of $0.5\%\~5\%$ agar-agar solution, were $0.09\~13.51\;kcal/g{\cdot}mol$.

• Korean Journal of Food Science and Technology
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• v.36 no.2
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• pp.276-282
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• 2004

Barley flakes were developed by extrusion cooking using broken kernels, by-products of the barley pearling process. Broken kernels from both non-waxy and waxy barley broken kernels were sufficiently gelatinized at the barrel temperature of over $100^{\circ}C$ and the moisture content of broken kernels of over 35%. Cutting and flaking roll separating properties of pellets prepared from non-waxy barley broken kernels were better than those of waxy barley broken kernels. Characteristics of pellets prepared by extrusion cooking in different mixing ratios of non-waxy and waxy barley broken kernels were investigated. As the mixing ratio of waxy barley broken kernels increased, RVA peak viscosity, apparent viscosity, and yield stress of prepared pellets decreased, while flow behavior index increased. As the mixing ratio of waxy barley broken kernels increased, compressive strength and bulk density of deep-fat fried flakes drastically decreased, and the size of air cells on cross-section increased, and thickness of cell-constituting bodies decreased. Sensory evaluation results showed that acceptability for texture and taste of flakes inclosed as the mixing ratio of waxy barley broken kernels increased, and optimum mixing level of waxy barley broken kernels appeared to be 30-40%.

• The Journal of Engineering Geology
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• v.22 no.3
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• pp.343-351
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• 2012

This study proposes a modified equation to calculate the factor of safety for an infinite slope considering the saturation depth ratio as a new variable calculated from rainfall infiltration into unsaturated soil. For the proposed equation, this study introduces the concepts of the saturation depth ratio and subsurface flow depth. Analysis of the factor of safety for an infinite slope is conducted by the sequential calculation of the effective upslope contributing area, subsurface flow depth, and the saturation depth ratio based on quasi-dynamic wetness index theory. The calculation process makes it possible to understand changes in the factor of safety and the infiltration behavior of individual rainfall events. This study analyzes stability changes in an infinite slope, considering the saturation depth ratio of soil, based on the proposed equation and the results of soil column tests performed by Park et al. (2011 a). The analysis results show that changes in the factor of safety are dependent on the saturation depth ratio, which reflects the rainfall infiltration into unsaturated weathered gneiss soil. Under continuous rainfall with intensities of 20 and 50 mm/h, the time taken for the factor of safety to decrease to less than 1.3 was 2.86-5.38 hours and 1.34-2.92 hours, respectively; in the case of repeated rainfall events, the time taken was between 3.27 and 5.61 hours. The results demonstrate that it is possible to understand changes in the factor of safety for an infinite slope dependent on the saturation depth ratio.