• Korean Journal of Remote Sensing
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• v.23 no.3
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• pp.221-227
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• 2007

We present an analysis of urban development and growth with reconnaissance satellite photographs of Columbus metropolitan area acquired by the Corona program in 1965. A two-dimensional polynomial linear transformation was used to rectify the photos against United State Geological Survey (USGS) Large-scale Digital Line Graph (DLG) data georeferenced to Universal Transverse Mercator (UTM) coordinates. The boundaries of the Columbus metropolitan area were extracted from the rectified Corona image mosaic using a Bayesian approach to image segmentation. The inferred 1965 urban boundaries were compared with 1976 USGS Land Use and Land Cover (LULC) data and boundaries derived from 1988 and 1994 Landsat TM images. The urban area in and around Columbus approximately doubled from 1965 to 1994 (${\sim}110%$) along with population growth from 1960 to 1998 (${\sim}50%$). Most of the urban expansion results from development of residential units.

• Fisheries and Aquatic Sciences
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• v.27 no.3
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• pp.171-179
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• 2024

A study was conducted to evaluate dietary valine (Val) requirement for Pacific white shrimp (Penaeus vannamei). Five isonitrogenous (353 g/kg) and isocaloric (4.08 kcal/g) semi-purified diets containing graded levels of Val (2.7, 5.1, 8.7, 12.1 or 16.0 g/kg) were formulated. Quadruplicate groups of 12 shrimp (average body weight: 0.46 ± 0.00 g) were fed one of the experimental diets (2%-5% of total body weight) for 8 weeks. Maximum weight gain was observed in 8.7 g/kg Val group. However, the growth performance was reduced when Val concentration in diets were higher than 12.1 g/kg. Feed conversion ratio was significantly increased with 2.7 and 16.0 g/kg Val inclusion. Shrimp fed the diets containing 2.7 g/kg Val showed significantly lower protein efficiency ratio, whole-body crude protein and Val concentrations. Dietary inclusion of Val significantly improved the relative expression of insulin-like growth factor binding protein and immune-related genes (prophenoloxidase, lysozyme and crustin) in the hepatopancreas and 8.7 g/kg Val group showed highest expression among all the groups. The dietary requirement of Val for maximum growth of juvenile P. vannamei, estimated using polynomial regression analysis on growth, was 9.54 g/kg of Val (27.2 g/kg based on protein level) and maximum growth occurred at 9.27 g/kg of Val (26.2 g/kg based on protein level) based on broken-line regression analysis.

• Food Science and Biotechnology
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• v.15 no.5
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• pp.715-720
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• 2006

This study was performed to develop a predictive model for the growth kinetics of Listeria monocytogenes in tryptic soy broth (TSB) using a response surface model with a combination of potassium lactate (PL), temperature, and pH. The growth parameters, specific growth rate (SGR), and lag time (LT) were obtained by fitting the data into the Gompertz equation and showed high fitness with a correlation coefficient of $R^2{\geq}0.9192$. The polynomial model was identified as an appropriate secondary model for SGR and LT based on the coefficient of determination for the developed model ($R^2\;=\;0.97$ for SGR and $R^2\;=\;0.86$ for LT). The induced values that were calculated using the developed secondary model indicated that the growth kinetics of L. monocytogenes were dependent on storage temperature, pH, and PL. Finally, the predicted model was validated using statistical indicators, such as coefficient of determination, mean square error, bias factor, and accuracy factor. Validation of the model demonstrates that the overall prediction agreed well with the observed data. However, the model developed for SGR showed better predictive ability than the model developed for LT, which can be seen from its statistical validation indices, with the exception of the bias factor ($B_f$ was 0.6 for SGR and 0.97 for LT).

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.7
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• pp.1013-1018
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• 2014

In this study, we developed kinetic models to predict the growth of pathogenic Escherichia coli on cheeses during storage at constant and changing temperatures. A five-strain mixture of pathogenic E. coli was inoculated onto natural cheeses (Brie and Camembert) and processed cheeses (sliced Mozzarella and sliced Cheddar) at 3 to 4 log CFU/g. The inoculated cheeses were stored at 4, 10, 15, 25, and $30^{\circ}C$ for 1 to 320 h, with a different storage time being used for each temperature. Total bacteria and E. coli cells were enumerated on tryptic soy agar and MacConkey sorbitol agar, respectively. E. coli growth data were fitted to the Baranyi model to calculate the maximum specific growth rate (${\mu}_{max}$; log CFU/g/h), lag phase duration (LPD; h), lower asymptote (log CFU/g), and upper asymptote (log CFU/g). The kinetic parameters were then analyzed as a function of storage temperature, using the square root model, polynomial equation, and linear equation. A dynamic model was also developed for varying temperature. The model performance was evaluated against observed data, and the root mean square error (RMSE) was calculated. At $4^{\circ}C$, E. coli cell growth was not observed on any cheese. However, E. coli growth was observed at $10{\circ}C$ to $30^{\circ}C$C with a ${\mu}_{max}$ of 0.01 to 1.03 log CFU/g/h, depending on the cheese. The ${\mu}_{max}$ values increased as temperature increased, while LPD values decreased, and ${\mu}_{max}$ and LPD values were different among the four types of cheese. The developed models showed adequate performance (RMSE = 0.176-0.337), indicating that these models should be useful for describing the growth kinetics of E. coli on various cheeses.

• Food Science and Biotechnology
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• v.17 no.6
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• pp.1316-1321
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• 2008

This study was conducted to develop a model to describe the effect of antimicrobials [potassium sorbate (PS), potassium lactate (PL), and combined PL and sodium diacetate (SDA, PLSDA)] on the growth parameters of Listeria monocytogenes such as specific growth rate (SGR) and lag phase periods (LT) in air-dried raw sausages as a function of storage temperature (4, 10, 16, and $25^{\circ}C$). Results showed that the SGR of L monocytogenes was dependent on the storage temperature and level of antimicrobials used. The most effective treatment was the 4% PLSDA, followed by the 2% PLSDA and 4% PL and 0.2% PS exhibited the least antimicrobial effect. Increased growth rates were observed with increasing storage temperatures from 4 to $25^{\circ}C$. The growth data were fitted with a Gompertz equation to determine the SGR and LT of the L. monocytogenes. Six polynomial models were developed for the SGR and LT to evaluate the effect of PS (0.1, 0.2%) and PL (2,4%) alone and PLSDA (2, 4%) on the growth kinetics of L. monocytogenes from 4 to $25^{\circ}C$.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.9
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• pp.1303-1310
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• 2014

A 12 week growth study was carried out to investigate the supplemental effects of dietary garlic powder (GP) on growth, feed utilization and whole body composition changes of fingerling sterlet sturgeon Acipenser ruthenus (averaging weight, 5.5 g). Following a 24-h fasting, 540 fish were randomly distributed to each of 18 tanks (30 fish/tank) under a semi-recirculation freshwater system. The GP of 0.5% (GP0.5), 1% (GP1), 1.5% (GP1.5), 2% (GP2) and 3% (GP3) was added to the control diet (GP0) containing 43% protein and 16% lipid. After the feeding trial, weight gain (WG) of fish fed GP1.5, GP2 and GP3 were significantly higher (p<0.05) than those of fish fed GP0, GP0.5 and GP1. Feed efficiency and specific growth rate (SGR) showed a similar trend to WG. Protein efficiency ratio of fish fed GP1.5, GP2, and GP3 were significantly higher (p<0.05) than those of fish groups fed the other diets. A significant difference (p<0.05) was found in whole body composition (moisture, crude protein, crude lipid, ash, and fiber) of fish at the end of the experiment. Significantly higher (p<0.05) protein and lipid retention efficiencies (PRE and LRE) were also found in GP1.5, GP2, and GP3 groups. Broken-line regression model analysis and second order polynomial regression model analysis relation on the basis of SGR and WG indicated that the dietary optimal GP level could be greater than 1.77% and 1.79%, but less than 2.95% and 3.18% in fingerling sterlet sturgeon. The present study suggested that dietary GP for fingerling sterlet sturgeon could positively affect growth performance and protein retention.

• Structural Engineering and Mechanics
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• v.85 no.4
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• pp.531-543
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• 2023

The existing concrete bridges are time-varying working systems, where the maintenance strategy should be planned according to the time-varying performance of the bridge. This work proposes a time-dependent residual capacity assessment procedure, which considers the non-stationary bridge load effects under growing traffic and non-stationary structural deterioration owing to material degradations. Lifetime bridge load effects under traffic growth are predicated by the non-stationary peaks-over-threshold (POT) method using time-dependent generalized Pareto distribution (GPD) models. The non-stationary structural resistance owing to material degradation is modeled by incorporating the Gamma deterioration process and field inspection data. A three-span continuous box-girder bridge is illustrated as an example to demonstrate the application of the proposed procedure, and the time-varying reliability indexes of the bridge girder are calculated. The accuracy of the proposed non-stationary POT method is verified through numerical examples, where the shape parameter of the time-varying GPD model is constant but the threshold and scale parameters are polynomial functions increasing with time. The case study illustrates that the residual flexural capacities show a degradation trend from a slow decrease to an accelerated decrease under traffic growth and material degradation. The reliability index for the mid-span cross-section reduces from 4.91 to 4.55 after being in service for 100 years, and the value is from 4.96 to 4.75 for the mid-support cross-section. The studied bridge shows no safety risk under traffic growth and structural deterioration owing to its high design safety reserve. However, applying the proposed numerical approach to analyze the degradation of residual bearing capacity for bridge structures with low safety reserves is of great significance for management and maintenance.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.4
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• pp.859-867
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• 2014

This study was conducted to evaluate the optimum dietary lipid level in juvenile river puffer. Five semi-purified diets were formulated with corn oil to contain graded levels of lipid levels of 6, 9, 12, 15 and 18%. Fish averaging $8.32{\pm}0.02$ g randomly were fed the experimental diets in triplicate groups for 8 weeks. After the 8-weeks feeding trial, weight gain and specific growth rate of fish fed the 9% diet were significantly higher than those of fish fed the 15 and 18% diets (P<0.05) but there was not significantly different from that of fish fed the 6, 9 and 12% diets. Feed efficiency and protein efficiency ratio of fish fed the 6, 9 and 12% diets were significantly higher than those of fish fed the 18% diet (P<0.05). Visceralsomatic index of fish fed 18% diet was significantly higher than that of fish fed the 6% diet (P <0.05) but there was not significantly different from that of fish fed the 9, 12, 15 and 18% diets. No significant differences were observed in condition factor, hepatosomatic index and whole body composition among all the fish groups. Serum cholesterol and triglyceride fish fed of 18% diet were significantly higher than that of fish fed the other diets (P<0.05). Optimum dietary lipid levels by using broken-line model and by using second order polynomial were estimated at 7.01% and 8.98% for the maximum growth of fish respectively. Therefore, these results suggested that the optimum dietary lipid level could be greater than 7.01% but less than 8.98% for the maximum growth in juvenile river puffer.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.4
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• pp.915-922
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• 2014

This study was conducted to evaluate the optimum dietary protein level in juvenile river puffer. Five semi-purified diets were formulated by using casein to contain graded levels of protein levels of 35, 45, 50, 55 and 65%. Fish averaging $8.56{\pm}0.04g$ were randomly assigned to one of five experimental diets in triplicate groups for 8 weeks. After the 8-weeks of feeding trial, weight gain and feed efficiency of fish fed 45, 50 and 55% diets were significantly higher than those of fish fed 35 and 65% diets (P<0.05). Protein efficiency ratio of fish fed the 35% diet was significantly higher than those of fish fed 65% diet (P<0.05), but there were no significant difference among those of fish fed 45, 50 and 55% diets. Specific growth rate of fish fed 50% diet was significantly higher than those of fish fed 35 and 65% diets (P<0.05), but there was no significant difference among those of fish fed 45, 50 and 55% diets. No significant differences were observed in condition factor, hepatosomatic index, visceralsomatic index and survival among those of fish fed all the diets. Optimum dietary protein levels by using broken-line model and by using second order polynomial were estimated at 45.9% and 51.6% for the maximum growth of fish respectively. Therefore, these results suggested that the optimum dietary protein level could be greater than 45.9% but less than 51.6% for the maximum growth in juvenile river puffer.

• Journal of the Korean Dietetic Association
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• v.25 no.1
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• pp.30-43
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• 2019

This study compared the predictive models for the growth kinetics of Staphylococcus aureus in ham rice balls. In addition, a semi-quantitative risk assessment of S. aureus on ham rice balls was conducted using FDA-iRISK 4.0. The rice was rounded with chopped ham, which was mixed with mayonnaise (SHM), soy sauce (SHS), or gochujang (SHG), and was contaminated artificially with approximately $2.5{\log}\;CFU{\cdot}g^{-1}$ of S. aureus. The inoculated rice balls were then stored at $7^{\circ}C$, $15^{\circ}C$, and $25^{\circ}C$, and the number of viable S. aureus was counted. The lag phases duration (LPD) and maximum specific growth rate (SGR) were calculated using a Baranyi model as a primary model. The growth parameters were analyzed using the polynomial equation as a function of temperature. The LPD values of S. aureus decreased with increasing temperature in SHS and SHG. On the other hand, those in SHM did not show any trend with increasing temperature. The SGR positively correlated with temperature. Equations for LPD and SGR were developed and validated using $R^2$ values, which ranged from 0.9929 to 0.9999. In addition, the total DALYs (disability adjusted life years) per year in the ham rice balls with soy sauce and gochujang was greater than mayonnaise. These results could be used to calculate the expected number of illnesses, and set the hazard management method taking the DALY value for public health into account.