• Journal of Advanced Marine Engineering and Technology
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• v.35 no.2
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• pp.216-223
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• 2011

TVC is a kind of ejector which entrains low pressure working fluid by using the high pressure working fluid. While most papers relating with ejectors treat the working fluid as an ideal gas for convenience, the fluid doesn't behave as the ideal gas when phase change occurs. In this study, numerical analysis is conducted by applying Redlich-Kwong equation of state instead of ideal gas equation of state. Two turbulent models are compared for the better prediction and SST k-${\omega}$ model is preferred rather than realizable k-${\epsilon}$ model by comparison. Energy loss at the diffuser inlet and throat using the real gas equation of state is relatively greater than that using ideal gas law. For the real gas case, pressure increase due to shock train at the diffuser outlet is relatively smaller than the ideal gas case, but both cases have the same pressure increase due to a pseudo shock.

• Food Science of Animal Resources
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• v.40 no.6
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• pp.896-907
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• 2020

Imaging technique or computer vision (CV) technology has received huge attention as a rapid and non-destructive technique throughout the world for measuring quality attributes of agricultural products including meat and meat products. This study was conducted to test the ability of CV technology to predict the quality attributes of beef. Images were captured from longissimus dorsi muscle in beef at 24 h post-mortem. Traits evaluated were color value (L*, a*, b*), pH, drip loss, cooking loss, dry matter, moisture, crude protein, fat, ash, thiobarbituric acid reactive substance (TBARS), peroxide value (POV), free fatty acid (FFA), total coliform count (TCC), total viable count (TVC) and total yeast-mould count (TYMC). Images were analyzed using the Matlab software (R2015a). Different reference values were determined by physicochemical, proximate, biochemical and microbiological test. All determination were done in triplicate and the mean value was reported. Data analysis was carried out using the programme Statgraphics Centurion XVI. Calibration and validation model were fitted using the software Unscrambler X version 9.7. A higher correlation found in a* (r=0.65) and moisture (r=0.56) with 'a*' value obtained from image analysis and the highest calibration and prediction accuracy was found in lightness (r²_c=0.73, r²_p=0.69) in beef. Results of this work show that CV technology may be a useful tool for predicting meat quality traits in the laboratory and meat processing industries.

• Journal of the Korean Society of Propulsion Engineers
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• v.5 no.1
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• pp.18-25
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• 2001

The results of systematic numerical experiments of secondary gas injection thrust vector control are presented. The effects of secondary injection system such as injection location and nozzle divergent cone angle onto the overall performance parameters such as thrust ratio, specific impulse ratio and axial thrust augmentation, are investigated. Complex nozzle exhaust flows induced by the secondary jet penetration is numerically analyzed by solving unsteady three-dimensional Reynolds-averaged Navier-Stokes equations with Baldwin-Lomax turbulence model for closure. Numerical simulations compared with the experiments of secondary air injection into the rocket nozzle of $9.6^{\cire}$ divergent half angle showed good agreement. The results obtained in terms of overall performance parameters showed that locating the secondary injection orifice further downstream of primary nozzle ensures the prevention of occurrence of reflected shock wave, therefore is suitable for efficient and stable thrust vectoring over a wide range of use.

• The Korean Journal of Food And Nutrition
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• v.16 no.4
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• pp.328-333
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• 2003

When the extract of the medicinal plants, Kaempferia galanga L., Zanthoxylum bungeanum, Eugenia caryophyllata, Foeniculum vulgare, was added to Naengmyeon broth with the concentration of 0.1% and 0.3% each, its effect during the preservation time of broth was investigated. pH of the extract-added broth was lower than control at the initial, but higher after 72 hours of preservation, which showed that when it added 0.1% and 0.3% of extract to the broth, pH of Kaempferia galanga L. was 4.92 and 5.08 respectively, whereas control was 4.60. Titratable acidity was lowered after 48 hours and also Kaempferia galanga L. showed the lowest acidity with 0.66 for adding 0.1% of its extract and 0.55 for 0.3% of adding, but control was 0.89 at the time of 90 hours of preservation, and then it showed to be lowered in the order of Zanthoxylum bungeanum, Eugenia caryophyllata and Foeniculum vuigare. Turbidity of each broth added the extracts of four of the medicinal plants was 7.5∼7.9 and 7.9∼8.2, respectively for 0.1% and 0.3% of concentration at the initial, but it began to lower and 90 hours later it was 8.8∼9.5 and 8.7∼9.0 respectively, whereas control was 10.8. Total viable cells(TVC) and coliform bacteria(CB) were increased with great at the 72 hours of preservation time, and Kaempferia galanga L. was the most effective, which when control was 4.8${\times}$10 CFU/ml at 72 hours, TVC was 1.7${\times}$10 CFU/ml for the addition of 0.1% of extract and 0.9${\times}$10 CFU/ml for 0.3%. CB was 3.2${\times}$10 CFU/ml for 0.1% and 1.7${\times}$10 CFU/ml for 0.3% respectively and 6.0 ${\times}$ 10 CFU/ml for control at the time of 72 hours, and it was lowered in the order of Zanthoxylum bungeanum, Eugenia caryophyllata and Foeniculum vulgare. Volatile basic nitrogen content detected that control was 2.67mg% at first, and then increased to 3.96mg% at 90 hours of preservation, but the broth added with the extract of Kaempferia galanga L. was 2.58mg% for 0.1% and 2.47mg% for 0.3% at the initial, and at 90 hours it was 3.64mg% and 3.33mg% respectively. The results of adding the extracts of four medicinal plants for the improvement of the preservation time of Naengmyeon broth, were that the most effective medicinal plant was Kaempferia galanga L. and the antimicrobial activity of the medicinal plant extracts for Naengmyeon broth was highly effective after 3 days of preservation time.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.12
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• pp.1895-1904
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• 2015

Foodborne illness associated with food service establishments is an important food safety issue in Korea. In this study, foodborne pathogens (Bacillus cereus, Clostridium perfringens, Escherichia coli, pathogenic Escherichia coli, Listeria monocytogenes, Salmonella spp., Staphylococcus aureus, and Vibrio parahaemolyticus) and hygiene indicator organisms [total viable cell counts (TVC), coliforms] were analyzed for food and environmental samples from foodservice establishments at schools in Gyeonggi province. Virulence factors and antimicrobial resistance of detected foodborne pathogens were also characterized. A total of 179 samples, including food (n=66), utensil (n=68), and environmental samples (n=45), were collected from eight food service establishments at schools in Gyeonggi province. Average contamination levels of TVC for foods (including raw materials) and environmental samples were 4.7 and 4.0 log CFU/g, respectively. Average contamination levels of coliforms were 2.7 and 4.0 log CFU/g for foods and environmental swab samples, respectively. B. cereus contamination was detected in food samples with an average of 2.1 log CFU/g. E. coli was detected only in raw materials, and S. aureus was positive in raw materials as well as environmental swab samples. Other foodborne pathogens were not detected in all samples. The entire B. cereus isolates possessed at least one of the diarrheal toxin genes (hblACD, nheABC, entFM, and cytK enterotoxin gene). However, ces gene encoding emetic toxin was not detected in B. cereus isolates. S. aureus isolates (n=16) contained at least one or more of the tested enterotoxin genes, except for tst gene. For E. coli and S. aureus, 92.7% and 37.5% of the isolates were susceptible against 16 and 19 antimicrobials, respectively. The analyzed microbial hazards could provide useful information for quantitative microbial risk assessment and food safety management system to control foodborne illness outbreaks in food service establishments.

• Journal of Energy Engineering
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• v.20 no.4
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• pp.318-329
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• 2011

This study focuses on enhancing the accuracy of consumption function of Korean natural gas for city gas. It is using time-series model with time-varying coefficients taking into account the recent abnormal temperature phenomenon and the changing gross domestic product (GDP) as important variables. This study estimates the cointegrating regression model for the long-run estimation and the error correction model for the short-run estimation. The consumption function of Korean natural gas is estimated to be influenced by the time-varying coefficients of GDP and temperature. Using the estimated time-series model with time-varying coefficients, this study forecasts the consumption of natural gas for city gas from July 2011 to December 2012. The consumption in 2011 would be 18,303 thousand tons, which is little different from the imported 18,681 thousand tons. The consumption of natural gas for city gas in 2012 is forecast to be 19,213 thousand tons. The consumption model of this study is needed to extend by considering the relative prices between natural gas and its substitutes, the scale of consumers and others.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.2
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• pp.37-50
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• 2023

This study aimed to examine the influence of a weight loss reality show watching on viewers' psychology and viewing effects by explicitly focusing on the Chinese TV show, Wow! Nice Figure (2019). Chinese women who had experience viewing Chinese TV show, Wow! Nice Figure and an experience of weight loss were the subject of the current study. The data collected from a total of 201 Chinese women were examined. Six variables; age, monthly income, occupation, education, BMI(Body Mass Index), and weight loss experience were included as control variables, and the data were analyzed with the use of SPSS 20.0. The results revealed that both simple and social viewing had been found to impact viewers' psychological attitudes positively. However, it was supported that simple and social viewing does not directly affect viewing satisfaction. Furthermore, the mediated effect of psychological variables within the relationship between simple viewing and viewing satisfaction and the relationship between social viewing and viewing satisfaction was investigated. From this study's results, the enhanced understanding of the impact of simple viewing, social viewing, and viewer's psychology on viewing satisfaction could be discussed.

• Journal of Food Hygiene and Safety
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• v.25 no.3
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• pp.251-257
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• 2010

The experiment was conducted to find out the nutritive value and microbial status of different wholesale cuts of goat carcass. The meat sample (4 cuts from each animal $\times$ 3 different age groups $\times$ 3 animals in each group = 36 samples) was obtained from 1-, 2-, and 3-year aged goats. The whole sale cuts were shoulder, rack, loin and leg of each goat carcass. To assess the quality of meat sample, the general appearance, color, smell, juiciness, proximate composition, pH, total bacteria, coliform bacteria, and yeast were studied. The mean pH value of different cuts ranges from 5.65-5.69 didn't differ significantly, but due to age differences the pH values (5.59-5.74) differed significantly (p < 0.01). The values of juiciness in different ages ranged from 32.24-42.10% which differed significantly (p < 0.01). The marbling of the cuts of rack portion was more pronounced than that of other cuts. The ranges of crude protein (CP) content of goat carcass (20.78-27.71%) differed significantly (p < 0.01) and leg portion contained higher CP than other portion. Fat contents of different cuts ranged from 2.66-11.47% differed significantly (P < 0.01). The moisture content of the carcass differed significantly which ranged from 69.20-73.31%. The ash content of the cuts of 1-year aged groups (0.99 $\pm$ 0.13%) was higher than that of other age groups and differed significantly (P < 0.01). The calcium (Ca) content did not differ significantly. The phosphorus (P) content was higher in one year old goat (0.15 $\pm$ 0.03%) than that of the goats of other ages. The total viable count (TVC) content of microorganisms ranging from 5.05-5.15 log cfu/g at different ages did not differ significantly. The coliform count (CC) of different cuts differed significantly (P < 0.01) which ranged from 2.56-3.05 log cfu/g; it also differed significantly (P < 0.05) in different ages (2.79-2.84 log cfu/g) and was higher in 1 year old goat carcass. The yeast count differed significantly in different cuts (P < 0.01) and ages (P < 0.05). From the study it is concluded that the age and different wholesale cuts have direct influence on quality of goat carcass.