• Korean Journal of Agricultural Science
• /
• v.42 no.1
• /
• pp.37-46
• /
• 2015

This study was carried out to determine the effect of storage condition, such as temperature and relative humidity (RH), on the change of sensory properties and free fatty acid composition of pre-packed Hanwoo loin (Musculus longissimus) until $21^{st}$ day of storage. The Hanwoo loin was sliced in $1.0{\pm}0.2cm$ thickness and each of the sliced pieces was packed in a foamed polystyrene tray with linear low-density polyethylene (LLD-PE) film to simulate the pre-packed Hanwoo loin sold in retail market, then stored in home-style refrigerator (Con; $5^{\circ}C$, 17%RH), and temperature and RH controled chambers (T1; $5^{\circ}C$, 55%RH, T2; $5^{\circ}C$, 85%RH, and T3; $-1^{\circ}C$, 99%RH), respectively. The sensory characteristics of pre-packed Hanwoo loin during storage in different conditions were measured on raw or after cooking. After 21 days of storage, the loin stored in T3 showed significantly high color and acceptability scores ($7.46{\pm}1.07$, $7.06{\pm}1.36$, respectively) on raw loin, and flavor and acceptability scores ($7.16{\pm}0.90$, $6.90{\pm}0.92$, respectively) on cooked loin than those of others (p<0.05). The concentration of 12 fatty acids of pre-packed Hanwoo loin during storage in different conditions were analysed. The concentration of oleic acid (C18:1, $39.92{\pm}3.22%$), palmitic acid (C16:0, $28.20{\pm}2.42%$), and stearic acid (C18:0, $12.59{\pm}2.79%$) was high in Hanwoo loin on $1^{st}$ day of storage. The concentration of palmitic acid of Hanwoo loin stored in T2 was increased significantly after $4^{th}$ day of storage (p<0.05), and the concentration of myristic acid(C14:0) of Hanwoo loin stored in treated chamber (T1 to T3) was significantly higher than Con after $14^{th}$ day of storage (p<0.05). The concentration of linolenic acid (C18:3) of Hanwoo loin was decreased significantly after $4^{th}$ day of storage in all tested storage conditions (p<0.05). However, there was no significant or consistent change in the concentration of oleic acid (C18:1) during storage period in every Hanwoo loin stored in tested conditions. Although, the concentration of total monounsaturated fatty acids (MUFA) was decreased in Con and T2 (p<0.05), there was no consistent change in the monounsaturated fatty acids to saturated fatty acids ratio (MUFA/SFA) during storage period (p>0.05). From those results, it was considered that storage condition affects on the sensory acceptability and fatty acid composition of pre-packed Hanwoo loin as storage period was increased.

• Progress in Medical Physics
• /
• v.19 no.1
• /
• pp.63-72
• /
• 2008

With recent advancement of the medical imaging systems and picture archiving and communication system (PACS), installation of digital radiography has been accelerated over past few years. Moreover, Computed Radiography (CR) which was well established for the foundation of digital x-ray imaging systems at low cost was widely used for clinical applications. This study analyzes imaging characteristics for two systems with different pixel sizes through the Modulation Transfer Function (MTF), Noise Power Spectrum (NPS) and Detective Quantum Efficiency (DQE). In addition, influence of radiation dose to the imaging characteristics was also measured by quantitative assessment. A standard beam quality RQA5 based on an international electro-technical commission (IEC) standard was used to perform the x-ray imaging studies. For the results, the spatial resolution based on MTF at 10% for Agfa CR system with I.P size of $8{\times}10$ inches and $14{\times}17$ inches was measured as 3.9 cycles/mm and 2.8 cycles/mm, respectively. The spatial resolution based on MTF at 10% for Fuji CR system with I.P size of $8{\times}10$ inches and $14{\times}17$ inches was measured as 3.4 cycles/mm and 3.2 cycles/mm, respectively. There was difference in the spatial resolution for $14{\times}17$ inches, although radiation dose does not effect to the MTF. The NPS of the Agfa CR system shows similar results for different pixel size between $100{\mu}m$ for $8{\times}10$ inch I.P and $150{\mu}m$ for $14{\times}17$ inch I.P. For both systems, the results show better NPS for increased radiation dose due to increasing number of photons. DQE of the Agfa CR system for $8{\times}10$ inch I.P and $14{\times}17$ inch I.P resulted in 11% and 8.8% at 1.5 cycles/mm, respectively. Both systems show that the higher level of radiation dose would lead to the worse DQE efficiency. Measuring DQE for multiple factors of imaging characteristics plays very important role in determining efficiency of equipment and reducing radiation dose for the patients. In conclusion, the results of this study could be used as a baseline to optimize imaging systems and their imaging characteristics by measuring MTF, NPS, and DQE for different level of radiation dose.

• Culinary science and hospitality research
• /
• v.20 no.6
• /
• pp.235-244
• /
• 2014

The purpose of this study was to investigate the effect of freezing and thawing rate on the physical properties of soybean sprouts to improve the quality of processed soybean sprouts during distribution and storage. Cooked soybean sprouts were frozen by air-blast freezing (ABF) system at $-45^{\circ}C$ or natural air convection freezing (NCF) system at $-24^{\circ}C$, then thawed using microwave oven by varying output power (0, 400, 800 and 1,000 W) until $75^{\circ}C$. The quality of soybean sprouts was measured by the water content, hardness and springiness. In addition, the internal microstructure of soybean sprouts was observed by optical microscope. For results, water content of soybean sprouts thawed by 1,000 W in a microwave showed the lowest value after natural air convection freezing. Springiness of soybean sprouts thawed by all amounts of output power was decreased in comparison with control. Hardness was increased only in soybean sprouts thawed by 1,000 W after air-blast freezing. However the gaps between springiness and hardness were relatively small with control at 1,000 W thawing, after air-blast freezing. Internal microstructure of the soybean sprouts was more damaged as freezing and thawing time were increased. In conclusion, high freezing and thawing rate might improves the quality of soy bean sprout, and IQF freezing and 1,000 W of microwave thawing appears to be the optimum condition for frozen HMR production. From the results freezing and thawing process parameters might can be use as quality control parameters as various type of sprout products processing.

• The Journal of Korean Academy of Prosthodontics
• /
• v.52 no.2
• /
• pp.82-89
• /
• 2014

Purpose: The purpose of this study was to observe the change of viscoelastic properties of dental resin cements during polymerization. Materials and methods: Six commercially available resin cement materials (Clearfil SA luting, Panavia F 2.0, Zirconite, Variolink N, RelyX Unicem clicker, RelyX U200) were investigated in this study. A dynamic oscillation-time sweep test was performed with AR1500 stress controlled rheometer at $32^{\circ}C$. The changes in shear storage modulus (G'), shear loss modulus (G"), loss tangent (tan ${\delta}$) and displacement were measured for twenty minutes and repeated three times for each material. The data were analyzed using one-way ANOVA and Tukey's post hoc test (${\alpha}$=0.05). Results: After mixing, all materials demonstrated an increase in G' with time, reaching the plateau in the end. RelyX U200 demonstrated the highest G' value, while RelyX Unicem (clicker type) and Variolink N demonstrated the lowest G' value at the end of experimental time. Tan ${\delta}$was maintained at some level and reached the zero at the starting point where G' began to increase. The tan ${\delta}$and displacement of the tested materials showed similar pattern in the graph within change of time. The displacement of all 6 materials approached to zero within 6 minutes. Conclusion: Compared to other resin cements used in this study, RelyX U200 maintained plastic property for a longer period of time. When it completed the curing process, RelyX U200 had the highest stiffness. It is convenient for clinicians to cement multiple units of dental prostheses simultaneously.

• Research in Plant Disease
• /
• v.9 no.4
• /
• pp.229-236
• /
• 2003

The 1080 epiphytic bacteria obtained from 370 samples of pome and stone fruits including apple, pear, peach, grape, apricot and Chinese quince were screened for antagonistic activity against postharvest pathogens, Penicillium expansum, Alternaria alternata and Botrytis cinerea. Among tested antagonistic bacteria, eight bacterial isolates inhibited mycelial growth of the postharvest pathogens and were identified as Bacillus amyloliquefaciens (three strains), B. megaterium, B. subtilis var. gladioli, B. licheniformis, B. pumilus and Serratia marcescens based on biochemical characteristics and utility of carbon and nitrogen compounds (Biolog system). Eight carbohydrates were evaluated for their effect on mycelial growth and germination of the postharvest pathogen, P. expansum to select nutrients for enhancing bio-control efficacy. The growth of four selected antagonists, B. amyloliquefaciens P43-2, B. amyloliquefaciens A71-2, B. licheniformis P94-1, and S. marcescens P76-9 were also tested. As a result, 1% glucose (w/v) strongly stimulated growth of the antagonists, suppressed mycelial growth of the postharvest pathogen, and had a little comparatively stimulatory effect on germination of the the postharvest pathogen. It was confirmed that the addition of 1% glucose (w/v) greatly enhanced biocontrol effect of B. amyloliquefaciens P43-2, B. licheniformis P94-1, and S. marcescens P76-9. Application of B. amyloliquefaciens P43-2, B. licheniformis P94-1, and S. marcescens P76-9 with the addition of 1% glucose (w/v) increased the control efficacy up to 48%, 46%, 14% compared with those of the antagonists without glucose, respectively. When the antagonists were applied to control postharvest disease caused by P. expansum in apple wounds, the population of B. amyloliquefaciens P43-2 and B. licheniformis P94-1 increased until 4 days after inoculation (DAI) of the antagonists and then decreased from 10 DAI. Meanwhile the population of S. marcescens P76-9 decreased at early stage (4 DAI), but increased from 7 DAI, and finally maintained constantly until 10 DAI in apple wounds.

• Journal of the Korean Society of Food Culture
• /
• v.13 no.1
• /
• pp.19-26
• /
• 1998

This study was carreid out to investigate present comsuming behavior and consumer preference of SEAFOODS as a stuff in KIMCHI making, adopting a questionaire survey for 500 housewives living in Korea except Chejudo Province. Frequency distribution and percentage of preferences were measured. Out of total housewives responded, 65.5% consider, THEY SHOULD EAT KIMCHI DAILY. Which conforms, kimchi is still an important side dish at most of the households On the other hand, some others consider EATING KIMCHI EVERY DAY is not neccesary(6.0%) or dislike it(0.5%). This result might suggest that kimchi may or may not be an essential sidedish for every households in the future. 96.3% of Housewives used fermented salited fish and 45% used seafoods as a staffing in making kimchi. Major reasons for adding seafoods in kimchi were: it improves teste and flavor(79.5%) and nutritional value(54.2%). Reasons for rejecting seafoods as a stuffing in making kimchi were: it worsens taste and flavor(13.5%), hygenic treatments of seafoods are below the necessary level(13.5%) and shelf life become shorter(12.8%), respectively. Among the fermented salted sauces, 84.9% and 69.1% of house wives responded as anchovy and shrimp sause were most favorite(base) material in Kimchi making, respectively. Out of total seafoods utilized in making kimchi,76.4%, 54.7% and 31.4% of housewives responded as oyster, small shrimp and sea-staghorn as the favorite seafoods in Kimchi making(raw material). Majority of housewives responded to develop it's taste and flavor to meet that of international one(86.5%) and that hygienic level(treatments) should be upgraded(50.9%).

• Korean journal of food and cookery science
• /
• v.14 no.5
• /
• pp.589-596
• /
• 1998

This study was carried out to evaluate the quality attributes of soy yogurts prepared by different types of oligosaccharides (fructooligosaccharide, galactooligosaccharide , isomaltooligosaccharide) and Bifidobacteria (B. bifidum B. breve, B. infantis) containing enzyme treated soy protein isolate in terms of pH, titratable acidity, total number of viable cells of Bifidobacteria, ${\alpha}$-galactosidase activity, organic acids, volatile compounds. The pH values of soy yogurts fermented by B. bifidum showed the highest significantly but those fermented by B. infantis showed the lowest significantly, while the titratable acidity of soy yogurts were vice versa. The viable cells of Bifidobacteria of all soy yogurts showed more than 10$\^$9/ CFU/ml and soy yogurts fermented by B. infantis showing below pH 4.6 showed more than 10$\^$9/ CFU/ml after storage at 4$^{\circ}C$ for 7 days. The activity of ${\alpha}$-galactosidase showed the highest in the culture of B. infantis among the Bifidobacteria tested. Among the Bifidobacteria tested, the contents of lactic acid and acetic acid showed the highest in soy yogurts fermented by B. infantis but citric acid and propionic acid were the lowest. Among the Bifidobacteria tested, the contents of n-hexanal showed the highest in soy yogurts fermented by B. breve and a little amounts of acetaldehyde were present in all soy yogurts.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.2
• /
• pp.87-95
• /
• 2016

This study examined the characteristics of the hourly demand of city gas in Korea and proposed multiple regression models to obtain precise estimates of the hourly demand of city gas. Forecasting the hourly demand of city gas with accuracy is essential in terms of safety and cost. If underestimated, the pipeline pressure needs to be increased sharply to meet the demand, when safety matters. In the opposite case, unnecessary inventory and operation costs are incurred. Data analysis showed that the hourly demand of city gas has a very high autocorrelation and that the 24-hour demand pattern of a day follows the previous 24-hour demand pattern of the same day. That is, there is a weekly cycle pattern. In addition, some conditions that temperature affects the hourly demand level were found. That is, the absolute value of the correlation coefficient between the hourly demand and temperature is about 0.853 on average, while the absolute value of the correlation coefficient on a specific day improves to 0.861 at worst and 0.965 at best. Based on this analysis, this paper proposes a multiple regression model incorporating the hourly demand ahead of 24 hours and the hourly demand ahead of 168 hours, and another multiple regression model with temperature as an additional independent variable. To show the performance of the proposed models, computational experiments were carried out using real data of the domestic city gas demand from 2009 to 2013. The test results showed that the first regression model exhibits a forecasting accuracy of MAPE (Mean Absolute Percentage Error) around 4.5% over the past five years from 2009 to 2013, while the second regression model exhibits 5.13% of MAPE for the same period.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.35 no.2
• /
• pp.158-163
• /
• 2006

Young radishes (YR, yeolmu in Korean) were cultivated in the soil with and without sulfur. YR-Control (without sulfur) was grown in the normal soil. YR were grown in the soil with $1,818\;g/m^3$ sulfur (YR-A) and $1,818\;g/m^3$ sulfur added lime mortar (YR-B) on it, respectively. Also, we prepared YR kimchis using YR-Control, YR-A and YR-B. The kimchis were fermented at $5^{\circ}C$ for 8 weeks. The growth inhibitory effects of AGS human gastric adenocarcinoma cells of the YR samples and kimchis were investigated. YR kimchis after $4\~5$ weeks at $5^{\circ}C$ showed higher acidity of $0.88\~1.20\%$ with pH $4.3\~4.5$ and the YR kimchis kept approximately pH 4.0 until 8 weeks. The kimchi A and B using YR-A and YR-B showed faster fermentation time, higher level of Leuconostoc sp. and lower level of Lactobacillus sp. during the fermentation, comparing to the control kimchi using YR-Control. Juices from YR-A and YR-B showed higher growth inhibitory effects of AGS human gastric adenocarcinoma cells than the juice from YR-Control at the same concentration. The growth inhibitory effect of YR-A was similar to that of the YR-B. The kimchi A and B juices also exhibited higher inhibitory effects $(74\%)$ on the growth of AGS human gastric adenocarcinoma cells than that of the control kimchi $(57\%)$ at the higher concentration of $20{\mu}L/assay$. Methanol extracts from the YR-kimchis also led to the similar results to the results of the juices. These results suggested that preparing of kimchi using differently cultivated YR especially in the soil with sulfur, which can help to synthesize sulfur-containing compounds, could increase the growth inhibitory effects of AGS human gastric adenocarcinoma cells.

• Journal of radiological science and technology
• /
• v.29 no.4
• /
• pp.267-274
• /
• 2006

The evaluation of GB stones with ultrasound has proved to be useful procedure in patient with symptoms of cholelithiasis. GB is evaluated for size, wall thickness, presence of internal reflections within the lumen and posterior acoustic shadowing or enhancement in Ultrsonography. The patient position should be shifted during procedure to demonstrate further the presence of stone within the GB. Patient scanned at the Rt. subcostal region in supine, right lateral, Lt. down decubitus, and upright sitting position. So GB stone should shift to dependent area of GB. Often, GB is not markedly distended in the presence of cholethiasis, and so the diagnosis becomes more difficult. One of the more difficult areas for detection of a GB stones are embeded in the cystic duct region. And since the GB is adjacent to the duodenum and hepatic flexure, its may be difficult to visualizing a GB stone. When patient study position changes frome supine to other position, stones displaced the site. But if its are polyps, not changes the site whatever patient positions. It is very important to what make different GB stones or polyps. We have studied about mobility of GB stones according to the patients position(supine, Lt. down decubitus, $30^{\circ} LAO. sitting and hand-knee). So we have a result, stones wherever localized within the GB, changed 100% its position in the hand-knee position and the others appeared at least 90%. In this study, when a large stones are located through fundus-body and body-neck, does not changing the stones position in spite of varied patient's positions. But hand-knee positions can identified GB stones, because its make changed the position of stons from posterior wall to anterior wall within the GB. We recommend the hand-knee position for differentiation GB stones from polyps.