• Journal of radiological science and technology
• /
• v.32 no.2
• /
• pp.177-182
• /
• 2009

Purpose : This study presents the optimization of flip angle (FA) to obtain higher contrast to noise ratio (CNR) and lower specific absorption rate (SAR). Materials and Method : T1-weighted images of the cerebrum of brain were obtained from 50$^\circ$ to 130$^\circ$ FA with 10$^\circ$ interval. Signal to noise ratios (SNRs) were calculated for white matter (WM), gray matter (GM), and background noise. The proper FA was analyzed by T-test statistics and Kruskal-wallis analysis using R1 = 1- exp ($\frac{-TR}{T1}$) and Ernst angle cos $\theta$ = exp ($\frac{-TR}{T1}$). Results : The SNR of WM at 130$^\circ$ FA is approximately 1.6 times higher than the SNR of WM at 50$^\circ$. The SNR of GM at 130$^\circ$ FA is approximately 1.9 times higher than the SNR of GM at 50$^\circ$. Although the SNRs of WM and GM showed similar trends with the change of FA values, the slowdown point of decrease after linear fitting were different. While the SNR of WM started decreasing at 120$^\circ$ FA, the SNR of GM started decreasing at less than 110$^\circ$. The highest SNRs of WM and GM were obtained at 130$^\circ$ FA. The highest CNRs, however, were obtained at 80$^\circ$ FA. Conclusion : Although SNR increased with the change of FA values from 50$^\circ$ to 130$^\circ$ at 3T SE T1WI, CNR was higher at 80$^\circ$ FA than at the usually used 90$^\circ$ FA. In addition, the SAR was decreased by using smaller FA. The CNR can be increased by using this optimized FA at 3T MR SE T1WI.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.50 no.1
• /
• pp.39-49
• /
• 2014

Morphological and positional characteristics of anchovy aggregations, confirmed by trawling, were examined in two locations of the southern part of theWest Sea (T1) and the western side of South Sea (T11) of South Korea. Morphological characteristics (mean length, height and area) of the anchovy aggregations at T1 were smaller than those at T11, however the positional characteristics (distributional depth and bottom depth) of the aggregations at T1 were larger than those at T11. Diverse dataset such as the ship's cruise track, the cruse map, and interpolated three-dimensional-like water temperature were visualized in multiple dimensions. For a comprehensive understanding of the anchovy aggregations within their surrounding circumstances, the interpolated water temperature transferred to the location of anchovy aggregations at both stations were visualized based on geospatial information. Using quantitative investigation, the overall range of change in water temperature and salinity of anchovy aggregations at stations was considerably small. However, the water temperature and salinity of anchovy aggregations at T11 were somewhat higher than those at T1.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.25 no.1
• /
• pp.23-32
• /
• 2005

This experiment was carried out to determine on the growth characteristics, yield and palatability in mono-cropping(T1; sorghum $\times$ sudagrass hybrid, T2; soybean) and inter-cropping[T3; sorghum $\times$ sudagrass hybrid(1) + soybean(2)]. The results obtained are summarizes follows; In plant length. leaf length, leaf width and stem diameter of sorghum $\times$ sudagrass hybrid(SSH). T3(1) was lower than T1 at 1st cutting time. But in 2nd and 3rd cutting time. T3(1) was higher than T1 Stem diameter of T2 was higher than soybean of T3(2). but plant length, leaf length and leaf width of T2 were higher than T3(1). The leaf ratio of SSH in T3(1) was higher than T1 in the first cutting time, but T3(1) was higher than T1 at 2nd and 3rd cutting time. The number of tiller of T1 was higher than SSH of T3(1) at 1st cutting time, but T3(1) was higher than T1 at 2nd and 3rd cutting time. Dead stubble rate of SSH in T3(1) showed a little lower value than T1. Dry matter and fresh yield of T1 was higher than T2 and T3. But protein yield of T3 was higher than T1 The palatability of 1st cutting time was 100.0. 76.8 and $18.5\%$ on T2, T3 and T1, respectively.

• Journal of Magnetics
• /
• v.21 no.1
• /
• pp.115-124
• /
• 2016

The present study analyzes T1 TSE and T1 slice sel. IR (dark_fluid) signal strength according to the degree of gadolinium contrast agent dilution and analyzes the turbo factors with regard to changes in the maximum and overall signal strength to study correlations between changes and signal-to-noise ratios (SNRs) and compare peak-to-peak SNR (PSNR) enhancement in order to improve the quality of T1-weighted images. Enhancement TR (600 msec) evaluated to determine the T1 TSE turbo factor and obtain the maximum signal strength, T1WI were used sequentially to experiment with turbo factors_1-4. T1 slice sel. IR (dark-fluid) was used to sequentially test turbo factors_2-5 but not turbo factor_1 at a TR (1500 msec) and compare data at an increase in T1 of 900 msec. The T1 TSE was reduced according to the contrast agent concentration. Phantom signal strength increased, whereas turbo factors_1-4 exhibited maximum signal strength at a concentration of 3 mmol, followed by a gradual decrease. In the turbo factors_2-5, the signal strength increased sharply to maximum signal strength at 0.7 mmol, followed by a reduction. T1 TSE had a greater maximum signal strength than did T1 slice sel. IR (dark_fluid). A comparison of SNR found that T1 TSE imaging was superior (33.3 dB) in turbo factor_1 and T1 slice sel. IR (dark_fluid) was highest (33.9 dB) at turbo factor_5. A PSNR comparison analysis was not sufficient to distinguish between the images obtained with both techniques at 30 dB or higher under all experimental conditions.

• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.2
• /
• pp.259-262
• /
• 2004

The ability of Modified Glucomannan (MG) to bind T-2 toxin (T-2) in the gastrointestinal tract has been tested in vivo by feeding 120 five-wk-old broiler chicken with the following six treatment diets, 1) Control diet; 2) Control+MG (0.1%); 3) Control+T-2 (500 ppb); 4) Control+T-2 (500 ppb)+MG (0.1%); 5) Control+T-2 (1,000 ppb) and 6) Control+T-2 (1,000 ppb)+MG (0.1%). Twenty birds were assigned to each treatment group, which had five experimental groups. Four birds of each experimental group were sacrificed at an interval of 30 min i.e. at 0, 30, 60, 90 and 120 min after feeding experimental diets. The whole gut contents of each bird were collected, dried and toxin concentration was determined. Percent T-2 recovered from the gut was significantly lower (p<0.05) in the groups fed MG at all the time intervals. The percent T-2 adsorbed by the MG at different T-2 levels (500 and 1,000 ppb) was 15.97 and 14.77, 22.53 and 22.67, 26.88 and 28.03, and 31.50 and 31.83 at 30, 60, 90 and 120 min, respectively.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.38 no.1
• /
• pp.21-29
• /
• 2015

A steady-state controllable M/G/1 queueing model operating under the {T:Min(T,N)} policy is considered where the {T:Min(T,N)} policy is defined as the next busy period will be initiated either after T time units elapsed from the end of the previous busy period if at least one customer arrives at the system during that time period, or after T time units elapsed without a customer' arrival, the time instant when Nth customer arrives at the system or T time units elapsed with at least one customer arrives at the system whichever comes first. After deriving the necessary system characteristics including the expected number of customers in the system, the expected length of busy period and so on, the total expected cost function per unit time for the system operation is constructed to determine the optimal operating policy. To do so, the cost elements associated with such system characteristics including the customers' waiting cost in the system and the server's removal and activating cost are defined. Then, procedures to determine the optimal values of the decision variables included in the operating policy are provided based on minimizing the total expected cost function per unit time to operate the queueing system under considerations.

• Research in Community and Public Health Nursing
• /
• v.12 no.1
• /
• pp.125-141
• /
• 2001

The purpose of this study was to investigate the factors affecting hearing loss in adolescent's use of PCPs, and to give the basic data for adolescent's hearing conservation program development and prevention education against their hearing loss. This study was a descriptive research about three factors affecting hearing loss; the knowledge and attitude about noise, the perception of hearing loss and the hearing threshold. The subjects of this study were 383 students in two general high schools and two vocational high schools in Teagu. They have been using PCPs but with no current or past ear disease. This study was carried out from Sep. 1. 2000 to Oct. 24, 2000. The instrument used for the knowledge and attitude about noise was a questionnaire developed by Rhee. Kyung Yong and Yi. Kwan Hyung(1996). The instrument used for the perception of hearing loss was a Smith Hearing Screening Questionnaire. A Belton Model 112 Audiometer. air-conduction hearing test instrument. was used for the hearing threshold. Data was analysed by a SPSS/Win 10.0 program with frequency. percentage, t-test. ANOVA and pearson correlation. The results of this study were as follows; 1. The average of concern about hearing scored the highest $3.66{\pm}0.70$. The average of perceived susceptibility scored $2.64{\pm}0.85$ and the average of knowledge about noise scored $2.13{\pm}0.56$. The average of total knowledge and attitude about noise scored $2.82{\pm}0.46$. The average of discomfort of hearing loss($2.51{\pm}0.81$) scored higher than that fear of hearing loss($1.35{\pm}0.53$). The average of total perception of hearing loss scored $1.93{\pm}0.59$. The hearing threshold of the subjects scored the highest at 500Hz(Lt. $23.21{\pm}6.62$, Rt. $23.39{\pm}7.02$) and scored higher in order of 1000Hz, 2000Hz, 4000Hz and 8000Hz. 2. The knowledge and attitude about noise and the perception of hearing loss were both affected only by one important characteristic, which was general and vocational high schools. The knowledge and attitude about noise raked (t=5.258, p=0.000), and perception of hearing loss raked(t=2.241. p=0.026). However. several other important characteristics also impacted significantly on the knowledge and attitudes about noise. They included grade (t = 1. 987. p=0.048), father's education(F=2.745. p=0.043), marks(F=3.157, p=0.044), drinking(t=2.307, p=0.022) and smoking(t=2.587, p=0.010). The left hearing threshold differed significantly by sex at 1000Hz(t=5.175, p<0.001) and 8000Hz (t=3.334, p<0.01). According to general and vocational high schools (p<0.001), at 500Hz (t=-5.056), 1000Hz (t=-5.253), 2000Hz (t=-4.905), 4000Hz (t=-4.704) and 8000Hz (t=-5.204) significant differences were also shown. Marks were significant at 1000Hz (F=3.824, p<0.05) and drinking was found to be significant at 500Hz(t=2.203, p<0.05). The right hearing threshold differed significantly by sex at l000Hz(t=5.557. p<0.001). 4000Hz(t=2.234. p<0.05) and 8000Hz (t=2.730. p<0.01). According to general and vocational high schools(p<0.001) at 500Hz (t=-4.730), 1000Hz(t=-6.271). 2000Hz (t=-4.573). 4000Hz(t=-3.554) and 8000Hz (t=-3.405) significant differences were also shown. Grades impacted at 500Hz(t=2.201. p<0.05) and 4000Hz(t=2.511. p<0.05), while marks were significant at l000Hz(F=4.1l5. p<0.05) and drinking was significant at 500Hz(t=2.333. p<0.05). 3. The left hearing threshold in accordance with use of PCPs differed significantly at 2000Hz(F=2.996. p=0.03l) according to volume level and at 8000Hz(F=2.197. p=0.022) according to duration${\times}$hours per day. The right hearing threshold differed significantly at l000Hz(F=3.075. p=0.028) according to volume level and at 8000Hz(F=2.925. p=0.034) according to duration. 4. The knowledge and attitudes about noise showed a light positive correlation with the perception of hearing loss. A positive correlation was shown. as stated previously in all Hz, between the left hearing threshold and the right hearing threshold, especially the highest correlation at 2000Hz(r=0.761. p=0.000). This study has shown that the factors related to adolescent's use of PCPs are important as they impact significantly an adolescent's hearing. These results then indicate that in future, when designing a hearing conservation program and prevention education this data should be considered.

• Asian-Australasian Journal of Animal Sciences
• /
• v.26 no.11
• /
• pp.1569-1576
• /
• 2013

The study was conducted to evaluate the effect of vitamin E and zinc supplementation on energy metabolites, lipid peroxidation, and milk production in peripartum Sahiwal cows. For this, thirty-two pregnant dry Sahiwal cows were selected at sixty days prepartum and divided into four groups viz control, $T_1$, $T_2$, and $T_3$ of eight each. Group $T_1$ were supplemented with zinc at 60 ppm/d/cow, group $T_2$ were supplemented with vitamin E at 1,000 IU/d/cow and group $T_3$ were supplemented with combination of vitamin E at 1,000 IU/d/cow and zinc at 60 ppm/d/cow during d 60 prepartum to d 90 postpartum. Blood samples were collected on d -60, -45, -30, -15, -7, -3, 0, 3, 7, 15, 30, 45, 60, 90, and 120 with respect to day of parturition and analysed for glucose, non esterified fatty acid, and thiobarbituric acid reactive substance. Body condition score was maintained significantly better (p<0.05) in $T_3$ than in the control, $T_1$ and $T_2$ groups. Overall glucose level was higher (p<0.05) in $T_3$ than control, $T_1$, and $T_2$ groups. Levels of nonesterified fatty acid, and thiobarbituric acid reactive substance were lower (p<0.05) in $T_3$ than control, $T_1$, and $T_2$ groups. Milk yield was higher (p<0.05) in $T_3$ than control, $T_1$, and $T_2$ groups. In conclusion, the present study indicated that the supplementation of vitamin E and zinc in peripartum Sahiwal cows enhanced milk production by reducing negative energy balance.

• Journal of Bio-Environment Control
• /
• v.11 no.4
• /
• pp.157-162
• /
• 2002

The efficient timer-controlled irrigation and the favorable fruiting position were investigated far highly quality melon fruits from Feb.18 to July Si 1999. The nutrient solution was supplied either at every hour from 6：00 to 18：00 (T-1) or at 6：00, 8：00, 10：00, 11：00, 12：00, 12：30, 13：00, 13：30, 14：00, 14：30, IS：00,16：00, and 17：00 (T-2). A fruit was set at the first node of the fruit bearing branch from the 10, 12, or 13th node of the main stem. Pot weight was maintained at almost n constant level, regardless of the daily integrated solar radiation in T-2. Soluble solids content (SSC) and fresh weight of fruit were not significantly different among the irrigation treatments at each harvesting time. At the first harvest, SSC and fresh weight of fruit were not significantly different between the fruiting positions within the irrigation treatment. At the second harvest, SSC was higher in T-2 than T-1. The SSC was low in the fruit of the loth node in T-1, while it was not significantly different between fruiting positions in T-2. Fruit fresh weight was the highest at the 12 and 13th nodes in T-1, and the 13th node in T-2. Fresh and dry weights of leaf except petiole, regardless of harvesting time, increased as the node position was higher, The higher the fruiting position was, the lower the leaf weight was. Therefore, it is recommended to irrigate more frequently during the mid-noon. Fruits can be harvested earlier at the lower nodes in the spring crop production.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.28 no.1
• /
• pp.41-48
• /
• 2008

This study was carried out investigate the effects of dietary supplementation of agricultural by-product feed(persimmon-pell+barley bran+fermented rice bran+activated carbon) on calves disease, growth and carcass characteristics of Korean native steer. A total of twenty Korean native steer were allocated into four feeding group and assigned to four dietary treatments: Control(normal concentrate as a basal diet), T1(1% addition of by-product feeds), T2(3% addition of by-product feeds) and T3(5% addition of by-product feeds). The calf diarrhea was the highest at Control, while T3 was the lowest. The breath disease was the lowest at T2, occurrence with diarrhea and breath disease was the highest at Control. The daily gain was orderly ranked as T2(0.76kg)>T1(0.7kg), T3(0.70kg)>Control(0.67kg). The back fat thickness was orderly ranked as T2>T3>Control>T1, eye muscle area was orderly ranked as T3>T1>Control>T2. Grade of meat quantity was the highest at T1(2.3), but fat color, firmness and maturity tends to have a similar result. The marbling score and quality grade of T2 were the highest at 5.0 and 3.5, respectively. Based on the study, agricultural by-product feeds are able to many used for various purposes at disease reduce, increment of meat quantity and improvement of quality grade.