• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.2D
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• pp.299-309
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• 2006

Railway noise and vibration has been recognized as major problems with the speed-up of rolling stock. As a kind of solution to these problems, the decrease of stiffness of track pad have been tried. However, in this case, overturning of rail due to lateral force should be considered because it can have effect on the safety of running train. Therefore, above two things - decrease of stiffness of track pad and overturning of rail due to lateral force - should be considered simultaneously for the appropriate determination of spring coefficient of track pad. With this viewpoint, minimum spring coefficient of track pad is estimated through the comparison between the theoretical relationship about the overturning of rail and 3-dimensional FE analysis result. Two kinds of Lateral force and wheel load are used as input loads. Extracted values from the conventional estimation formula and the Shinkansen design loads are used. It is found that the overturning of rail changes corresponding to the change of the stiffness of track pad and the ratio of lateral force to wheel load. Moreover, it is found that the analysis model can have influence on the results. Through these procedure, minimum spring coefficient of track pad is estimated.

• Journal of the Korean Society of Radiology
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• v.12 no.5
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• pp.669-675
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• 2018

This study aimed to investigate the difference of X-ray exposure by comparing and analyzing entrance surface dose and absorbed dose according to the frame change in coronary angiography using an X-ray machine. Moreover, appropriate frame selection measures for examination, including the effect of frame change on the image quality, were sought by measuring and analyzing the SNR and CNR of the image through image J. The study was conducted on 30 patients (19 males and 11 females) who underwent CAG at this hospital from June 2017 to October 2017. In regard to the patients, their age range was 49-82 years (mean of $65{\pm}9$ years), body weight was 45-91 kg (mean of $67{\pm}8.9kg$), height was 150-179cm (mean of $165.1{\pm}8.9kg$), and BMI was 19.5-30.5(mean of $24.5{\pm}2.9$). For the entrance surface dose and absorbed dose, air kerma value and DAP were obtained and analyzed retrospectively. The SNR and CNR were measured and analyzed through imageJ, and the result values were derived by applying the values to the formula. As for the statistical analyses, the correlations between the entrance surface dose and absorbed dose, and between the SNR and CNR were analyzed by using the SPSS statistical program. The relationship between the entrance surface dose and absorbed dose was not statistically significant for both 10 f/s and 15 f/s (p>0.05). In terms of the relationship between the SNR and CNR, the SNR ($3.374{\pm}2.1297$) and CNR ($0.234{\pm}0.2249$) in 10 f/s were $1.43{\pm}0.4861$ and $0.132{\pm}0.0555$ lower, respectively, than the SNR ($4.929{\pm}2.8532$) and CNR ($0.391{\pm}0.3025$) in 15 f/s, which were not statistically significant (p>0.05). In the correlation analysis, statistically significant results were obtained among the BMI, air kerma, and DAP; between air kerma and DAP; and between SNR and CNR (p<0.001, p<0.001). In conclusion, there was no significant difference between the entrance surface dose and absorbed dose even when the images were taken by changing the frame from 10 f/s to 15 f/s at the time of the coronary angiography. SNR and CNR increased at 15 f/s than at 10 f/s, but they were not statistically significant. Therefore, this study suggests that the concern of the patient and practitioner regarding image quality degradation, as well as the problem of X-ray exposure caused by imaging at 10 f/s and 15 f/s, may be reduced.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.4 no.1
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• pp.40-49
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• 1999

A laboratory flume experiment, using turbulence-generating acryl tank and natural sediments, was conducted to investigate the effects of salinity, concentration of suspended sediment, turbulence and clay minerals on the flocculation and settling of fine-grained suspended sediments. While experiments were run, a sequence of water samples were taken near the bottom of the tank to analyze the variations of size distribution and relative contents of clay minerals. The results of the salinity experiment indicate that median settling velocity ($W_{50}$) increases linearly with salinity. Different settling processes of suspended sediments under variable concentrations appear to be predictable, depending upon the range of the suspension concentration. At concentrations less than 200 mg/l, $W_{50}$ is rarely varied with concentration probably because of the individual--grain settling mode. In the range of 200 to 13,000 mg/l show $W_{50}$ and concentration a good relationship following an empirical formula: $W_{50}=0.45C^{0.44}$. This relationship, however, no longer holds in concentrations exceeding 13,000 mg/l; instead, a more or less reverse one is shown. This result suggests an effect of hindered settling. The turbulence effect is somewhat different from that of concentration. Turbulence accelerates the flocculation and settling susepended sediments at low concentration (200 mg/l), whereas at high concentration turbulence breaks floes down and impedes the settling. Size distribution of suspended sediments sampled near the bottom of the tank tend to be more negatively skewed and leptokurtic in turbulent conditions compared to those in static conditions. The clay mineral analysis from the sequential water samples shows that over time the content of smectite decreases most rapidly with illite remaining concentrated in suspension. This means that smectite, among other clay minerals, plays the most effective role in the flocculation of fine-grained sediment in saline water.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.9 no.2
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• pp.233-241
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• 2006

Purpose: This study was carried out to investigate the awareness of the weaning of food using questionnaires, and the relationship with the weight gain in young infants. Methods: From September 2005 to December 2005, we performed a survey on 141 guardians of young infants aged from 6 to 18 months, who visited the pediatric out-patient department at Dongguk University Medical Center. We calculated the total score for each responder from ten questions on the weaning of food and assessed the body weight percentile of each of the young infants. Results: The most commonly reported information source for weaning food was 'the friends around' by 62 respondents (44.0%); 54 (38.3%) responded that the definition of weaning food was the preparatory step before starting a solid diet. Most used a spoon (90.8%) to feed when weaning food with a thin gruel of rice (78.7%). The time for weaning of food was before breast or infant formula feeding (55.3%). Addition of cow's milk was around 12 months (77.3%). The mean score was 6.21; however this did not show a statistically significant correlation with weight gain in young infants. Conclusion: The overall awareness of weaning of food has improved; however, information from doctors has decreased. Although the relationship between the awareness of weaning of food and the growth of young infants was not statistically significant, further studies on weaning of food, with larger and controlled sample sizes may provide important information.

• Journal of agricultural medicine and community health
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• v.24 no.2
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• pp.269-289
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• 1999

This study was conducted to examine the relationship among health concern, health practice and ADL of elderly staying at home in a rural community and their affecting factors. Data were collected through direct interviews made with 480 old people aged more than sixty-five from November 15, 1998 to December 20, 1998. Out of 189 male and 291 female, the high-level group that showed high health concern accounted for 44.4%, the medium-level group for 13.1%, and the low-level group for 42.5%, in the health practice, the high-level group accounted for 3.8%, the medium-level group for 18.8%, and the low-level group for 77.5%. In the self-rated health status, the high-level group accounted for 29.0%, the medium-level group for 31.0%, and the low-level group for 40.0%, and in the ADL, the high ADL group accounted for 91.5%, and the low-level ADL group for 8.5%. The result of the chi-square test showed that for male, there was a significant relation between the health concern and the health practice index score. In the relation between the health practice index score and the self-rated health status, there was significant positive relationship between health practice index and self-rated health status, and in the relation between the health practice Index score and the ADL, old people with higher health practices showed good ADL(but not significant). Old people with good ADL also showed good self-rated health status. In the multiple regression analysis where the health practice was used as a dependent variable, the health concern was added to the sociodemographic variables as an independent variables, a formula was formed for male old people only and ones with high concern in health showed good health practice. In the multiple logistic regression analysis where the sociodemographic variables to which the health practices was added were used as an independent variable and the ADL as a dependent variable, the ADL appeared to be not good if for male old people the living costs were born by their sons and daughters and as for female old people their ages increased, but it was good if old people had sources of health information such as hospitals or health centers. The self-rated health status was worse, for male old people, if they had short living costs or diseases and for female old people, if they had spouses, living costs born by their sons and daughters or diseases, but it was better, for male old people, if they had periodical gatherings or carried out health practices a lot, and for female old people, if they had sources of health information such as hospitals or health centers or carried out health practices a lot. In view of the results stated above, the higher the old people had health concern, the more they carried out health practices, and the more they carried out health practices, the better they had ADL and self-rated health status that served as the level of health. Further, the better ADL, the better self-rated health status.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.6
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• pp.395-401
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• 2002

The combination of early heading time, maturing time and short grain-filling period is very important to develop early varieties in winter barley. The 4 parental half diallel crosses (parents, $F_1$s, $F_2$s) were cultivated at the field. The heading date was from April 3 to 26, maturing date from May 15 to 27 and grain-filling period from 31 days to 42 days, showing that the varietal differences about the 3 traits were remarkable. According to half diallel cross analyses, Dongbori 1 for heading time (late heading) was dominant, but Oweolbori (early heading) was recessive, showing partial dominance with high additive component of genetic variance. Dongbori 1 for maturing time was dominant, but Oweolbori was recessive, showing partial dominance with high additive variance. Reno for grain-filling period (short grain-filling period) was dominant, but Oweolbori (long grain-filling period) was recessive with additive, and partial dominance. There were highly significant mean squares for both GCA and SCA effects on the heading and maturing times, and GCA/SCA ratios for all traits were high, showing the additive gene effects more important. Sacheon 6 and Oweolbori had greater GCA effects for early heading and maturing times, and Dongbori 1 and Reno had greater GCA effects for late times. GCA effects were highly significant in $F_1$ and $F_2$ generations, showing high GCA/SCA ratios (7.02). The heading and maturing times in field were positively correlated with antifreeze proteins concentrations, accumulation, resistance to photoinhibition and winter survival, respectively) but the grain-filling period did negatively correlated with the trails.

• Journal of Sericultural and Entomological Science
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• v.7
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• pp.1-26
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• 1967

In order to develop the standards for the measurement of drought resistance in mulberry trees (Morus genus) the varietal differences of drought resistance were measured for 30 mulberry varieties, and the relationships between the drought resistance and the histological and physiological characteristics of mulberry leaves were investigated. The results were summarized as follows; 1. It is reasonable to use the drought resistance ratio, expressed by D/D'＊100, for the standard of drought resistance measurement for mulberry tree as a perennial tree crop. Where: D stands for growth amount(shoot length) in the plot of dry treatment, at the end of treatment. D' stands for an expected value of D which is expressed by B＊C/A. Here, A is the growth amount of wet treatment plot at the beginning of treatment, B is the growth amount of dry treatment plot at the beginning of treatment, and C is the growth amount of wet treatment plot at the end of treatment. 2. The results obtained from the application of above formula showed that the varieties Cadaneo, Tahozosaeng, Yongchunchuwu, Kaeryang suban. and Kabsun were highly resistant to drought and the varieties Jukmok, Shipyung, Sobun, Kaeryangzosaeng shipmoonza and Chungagokyo were highly susceptible. 3. Among leaf tissues. the rate of inter-cellular space showed the highest relationship with drought resistance. The correlation coefficient calculated (r=0.4153) was highly significant. Other leaf tissues such as epidermis and palisade showed no significant correlations with drought resistance. 4. The size and density of stomata were correlated to drought resistance. That is: Correlation between drought resistance and size of stomata(length ${\times}$ width)......r= -0. 3253(signif. at 5%) density(No. of stomata/l$\textrm{mm}^2$......r= +0.5047(signif. at 1%)

• Proceedings of the Korean Journal of Food and Nutrition Conference
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• 2001.12a
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• pp.39-74
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• 2001

The endeavors enhancing the grain quality of high-yielding japonica rice were steadily continued during 1980s∼1990s along with the self-sufficiency of rice production and the increasing demands of high-quality rices. During this time, considerably great, progress and success was obtained in development of high-quality japonica cultivars and qualify evaluation techniques including the elucidation of interrelationship between the physicochemical properties of rice grain and the physical or palatability components of cooked rice. In 1990s, some high-quality japonica rice caltivars and special rices adaptable for food processing such as large kernel, chalky endosperm aromatic and colored rices were developed and its objective preference and utility was also examined by a palatability meter, rapid-visco analyzer and texture analyzer. The water uptake rate and the maximum water absorption ratio showed significantly negative correlations with the K/Mg ratio and alkali digestion value(ADV) of milled rice. The rice materials showing the higher amount of hot water absorption exhibited the larger volume expansion of cooked rice. The harder rices with lower moisture content revealed the higher rate of water uptake at twenty minutes after soaking and the higher ratio of maximum water uptake under the room temperature condition. These water uptake characteristics were not associated with the protein and amylose contents of milled rice and the palatability of cooked rice. The water/rice ratio (in w/w basis) for optimum cooking was averaged to 1.52 in dry milled rices (12% wet basis) with varietal range from 1.45 to 1.61 and the expansion ratio of milled rice after proper boiling was average to 2.63(in v/v basis). The major physicochemical components of rice grain associated with the palatability of cooked rice were examined using japonica rice materials showing narrow varietal variation in grain size and shape, alkali digestibility, gel consistency, amylose and protein contents, but considerable difference in appearance and torture of cooked rice. The glossiness or gross palatability score of cooked rice were closely associated with the peak. hot paste and consistency viscosities of viscogram with year difference. The high-quality rice variety “Ilpumbyeo” showed less portion of amylose on the outer layer of milled rice grain and less and slower change in iodine blue value of extracted paste during twenty minutes of boiling. This highly palatable rice also exhibited very fine net structure in outer layer and fine-spongy and well-swollen shape of gelatinized starch granules in inner layer and core of cooked rice kernel compared with the poor palatable rice through image of scanning electronic mcroscope. Gross sensory score of cooked rice could be estimated by multiple linear regression formula, deduced from relationship between rice quality components mentioned above and eating quality of cooked rice, with high Probability of determination. The ${\alpha}$ -amylose-iodine method was adopted for checking the varietal difference in retrogradation of cooked rice. The rice cultivars revealing the relatively slow retrogradation in aged cooked rice were Ilpumbyeo, Chucheongbyeo, Sasanishiki, Jinbubyeo and Koshihikari. A Tongil-type rice, Taebaegbyeo, and a japonica cultivar, Seomjinbyeo, shelved the relatively fast deterioration of cooked rice. Generally, the better rice cultivars in eating quality of cooked rice showed less retrogiadation and much sponginess in cooled cooked rice. Also, the rice varieties exhibiting less retrogradation in cooled cooked rice revealed higher hot viscosity and lower cool viscosity of rice flour in amylogram. The sponginess of cooled cooked rice was closely associated with magnesium content and volume expansion of cooked rice. The hardness-changed ratio of cooked rice by cooling was negatively correlated with solids amount extracted during boiling and volume expansion of cooked rice. The major physicochemical properties of rice grain closely related to the palatability of cooked rice may be directly or indirectly associated with the retrogradation characteristics of cooked rice. The softer gel consistency and lower amylose content in milled rice revealed the higher ratio of popped rice and larger bulk density of popping. The stronger hardness of rice grain showed relatively higher ratio of popping and the more chalky or less translucent rice exhibited the lower ratio of intact popped brown rice. The potassium and magnesium contents of milled rice were negatively associated with gross score of noodle making mixed with wheat flour in half and the better rice for noodle making revealed relatively less amount of solid extraction during boiling. The more volume expansion of batters for making brown rice bread resulted the better loaf formation and more springiness in rice bread. The higher protein rices produced relatively the more moist white rice bread. The springiness of rice bread was also significantly correlated with high amylose content and hard gel consistency. The completely chalky and large gram rices showed better suitability for fermentation and brewing. Our breeding efforts on rice quality improvement for the future should focus on enhancement of palatability of cooked rice and marketing qualify as well as the diversification in morphological and physicochemical characteristics of rice grain for various value-added rice food processings.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.5
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• pp.545-549
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• 2001

To develop a natural antibacterial agent for fish bacterial diseases, antibacterial activity, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and bactericidal effect of cinnamon bark extract were examined against fish pathogenic bacteria. The antimicrobial effect of the extract to the fish diet was also estimated, Cinnamon bark extract showed the broad spectrum of antibacterial activity against fish pathogenic bacteria, especially, it had strong activity against Streptococcus iniae, Edwardsiella tarda and Listonella anguillarum. Its MIC was $75.8\sim189.6{\mu}g/mL$ against Cram positive bacteria, and $75.8\sim113.8{\mu}g/mL$ against Gram negative bacteria in liquid medium, It was found to show stronger bactericidal action against Gram negative bacteria than Cram positive bacteria. According to increasing concentrations of the extract, it resulted in a proportional reduction of viable cell counts of both S. iniae and L. anguillarum. The former was not detected by addition of $189.6{\mu}g/mL$ after 12 hours incubation and the latter by addition of $151.6{\mu}g/mL$ after 24 hours incubation, respectively. It was reasonable that fish diet was soaked in cinnamon bark extract for ten minutes. The relationship formula between the weight of fish diet and the extract absorbed to fish diet was Y=7.2726X+4.5083 ($R^2=0.9998$). The fish diet soaked in the extract inhibited the growth of all strains used in this study. Its antibacterial activity was stable at the range from $10^{\circ}C\;to\;35^{\circ}C$ during the storage period of 28 days. When the diet soaked in the extract was incubated in liquid medium at $35^{\circ}C$, it inhibited the growth of microorganisms inhabited in the diet.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.301-308
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• 2018

This study explores an analytical mathematical model designed to estimate the optimal debt ratio of the Korean automobile industry, which has a more significant effect on the national economy than that of other industries, and attempts to estimate the optimal debt ratio based on objective data. The analytical model is based on ROA and ROE which uses the debt ratio as an independent variable and employs ROS, TAT, and NFCL as the related parameters. Regarding the NFCL, the optimal debt ratio is usually defined as the debt ratio that maximizes the ROA and ROE and is calculated using analytical procedures, such as by adding an equation that considers the debt ratio and the linearity relationship to the analytical model. This is because the optimal debt ratio can be calculated reliably by making use of an estimated value within a certain range, which is derived from more than two calculations rather than a single estimation starting from one calculation formula. In this study, for the estimation of the optimal debt ratio, the ROA and ROE are expressed as a quadratic equation with the debt ratio as the independent variable. Using this analysis procedure, the optimal debt ratio obtained using the data from the Korean automobile industry over a sixteen year period, which would optimize the profitability of the Korean automobile industry, was found to be 188% of the debt ratio in the ROA and 213% of the debt ratio in the ROE. This result was obtained by overcoming the problem of the reliability of the estimation value in spite of the limitations of the logical theory of this study, and can be interpreted as meaning that maintaining a debt ratio of 188% to 213% can enhance the profitability and reduce the risks in the Korean automobile industry. Furthermore, this indicates that the existing debt ratio of the Korean automobile industry is lower than the optimal value within the estimated range. Consequently, it is necessary for corporations to change their future debt ratio policies, given that the purpose of debt ratio management is to maintain safety and increase profitability, and to take into account the characteristics of the specific industry.