• 대한방사선기술학회지:방사선기술과학
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• 제32권2호
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• pp.177-182
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• 2009

목 적 : 영상진단영역에서 이용되고 있는 3T(T, tesla) MR의 스핀에코(SE, spin echo) T1강조영상(T1-Weighted image)기법에서 숙임각(FA, flip angle)의 변화에 따른 영상의 질을 나타내는 신호대 잡음비(SNR, signal to noise ratio), 대조도 잡음비(CNR, contrast to noise ratio)를 평가한 후 특이흡수율(SAR, specific absorption rate)을 줄이면서 CNR를 향상시킬 수 있는 적정의 숙임각을 알아보고자 하였다. 대상 및 방법 : 고식적 스핀에코에서 통상적으로 사용하는 90$^\circ$ RF pulse 대신 50$^\circ$ RF pulse에서 130$^\circ$까지 10$^\circ$씩 증가시키면서 대뇌 T1강조영상을 획득하였다. 이 영상들에서 백질(WM, white matter), 회백질(GM, gray matter)과 배경(background)에서 각각 신호강도를 측정하여 SNR를 구하였고, 기존의 T1 이완곡선 R1 = 1- exp ($\frac{-TR}{T1}$)으로, 즉 Ernst angle cos $\theta$ = exp ($\frac{-TR}{T1}$)과의 관계성으로 T1강조영상에서 WM과 GM의 SNR과 CNR의 정규성 검정과 비모수 검정인 Kruskal-wallis 분석으로 적정의 숙임각을 알아보고자 하였다. 결 과 : WM와 GM의 신호강도와 배경잡음 신호강도를 이용하여 SNR를 구한 결과 WM의 SNR는 숙임각 50$^\circ$보다 130$^\circ$에서 1.6배 정도 증가하였고, GM의 SNR는 약 1.9배 정도 높게 나타났다. 두 조직의 SNR은 T1 이완곡선과 동일한 양상을 보여주고 있다. R1 = 1- exp ($\frac{-TR}{T1}$)으로 분석한 SNR의 신호증가가 둔화되는 기점이 WM은 120$^\circ$의 숙임각에서, GM은 110$^\circ$ 이후로 나타나 두 조직에서 다르게 나타나는 것을 알 수 있었다. WM과 GM의 SNR는 130$^\circ$의 숙임각에서 높았지만 CNR에 있어서는 80$^\circ$에서 최고 높게 나타났으며, 80$^\circ$ 전후의 숙임각에서는 감소하였다. 결론 : 3.0T MR의 SE T1강조영상 기법에서 숙임각의 증가에 따라 SNR는 증가하였지만 CNR는 이전까지의 임상에서 사용하는 숙임각이 90$^\circ$ 보다 적은 80$^\circ$에서 CNR이 최고로 나타나 통상적으로 사용하는 숙임각보다 10$^\circ$ 낮은 RF pulse duration time 사용함으로써 3T에서 문제로 제기된 SAR도 줄일 수 있었다. 앞으로 3.0T MR의 SE T1강조영상 기법에서 적정 숙임각을 사용함으로서 CNR을 높일 수 있을 것으로 기대되어진다.

• 수산해양기술연구
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• 제50권1호
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• pp.39-49
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• 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.

• 한국초지조사료학회지
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• 제25권1호
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• pp.23-32
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• 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
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• 제21권1호
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• pp.115-124
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• 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
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• 제17권2호
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• pp.259-262
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• 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.

• 산업경영시스템학회지
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• 제38권1호
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• pp.21-29
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• 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.

• 지역사회간호학회지
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• 제12권1호
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• pp.125-141
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• 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
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• 제26권11호
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• pp.1569-1576
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• 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.

• 생물환경조절학회지
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• 제11권4호
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• pp.157-162
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• 2002

본 연구는 타이머 제어에 의한 관수 시간과 착과절위가 과실 품질에 미치는 영향을 알아보기 위해서 1999년 2월 18일부터 7월 5일까지 수행되었다. 타이머에 의한 시간별 급액 처리는 6：00부터 18：00까지 한 시간 간격으로 관수된 것(T-1)과 6：00, 8：00, 10：00, 11：00, 12：00, 12：30, 13：00, 13：30, 14：00, 14：30, 15：00, 16：00, 및 17：00에 관수된 것(T-2)로 설정하였다. 과실은 그루당 1개씩 착과 시켰으며, 착과절위처리는 10, 12혹은 13절위 중 한 절에 착과시켰다. 포트 무게는 일일 적산 일사량과 무관하게 T-2에서 안정적인 값을 유지하였다. 당도와 과중은 수확시기별로 관수 처리구간에 유의적인 차이를 보이지 않았다. 1차 수확에서 당도와 과중은 관수 처리별 착과 절위간에 유의적인 차이를 보이지 않았던 반면. 2차 수확에서 당도는 T-1 처리구보다 T-2처리구에서 전반적으로 높았다. 착과절위별 비교 실험에서, T-1 처리구에서는 10절에서 낮았던 반면 T-2처리구에서는 착과절위별 차이를 보이지 않았다. 과중은 T-1 처리구의 12, 13절 그리고 T-2 처리구에서는 13절에서 가장 높았다. 엽병을 제외한 잎의 생체중과 건물중은 수확시기와 무관하게 높은 절위에서 높게 나타났다. 착과절위가 높을수록 엽중은 낮았다. 결과적으로, 관수는 낮에 자주 행하는 것이 바람직하며, 또한 봄 재배시 멜론 과실을 낮은 절위에 착과시키면 수확 시기를 앞당길 수 있을 것으로 사료된다.

• 한국초지조사료학회지
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• 제28권1호
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• pp.41-48
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• 2008

본 실험은 농산부산물인 감껍질, 맥강, 발효미강 및 활성탄을 혼합하여 만든 첨가 사료가 거세 한우의 질병, 성장 및 도체특성에 미치는 영향을 규명하고자 시험한 결과, 송아지 설사는 무처리구(Control)가 가장 발병율이 높았던 반면 첨가량이 가장 높은 T3구(5% 첨가구)가 가장 낮은 발병율을 보였다. 호흡기 질병 발병율은 3% 첨가구(T2)에 가장 낮게 나타났으며, 호흡기와 설사 동시 발생율은 Control구가 가장 높게 나타났다. 일당 증체량은 T2(0.76kg)>T1(0.7kg), T3(0.70)>Control구(0.67kg) 순으로 높게 나타났다. 등지방 두께는 T2>T3>Control>T1구 순으로 등심단면적은 T3>T1>Control>T2 순으로 나타났다. 그리고 육량등급은 1% 첨가구(T1)가 2.3은 가장 높게 나타났다. 지방색, 조직감, 성숙도에서는 상호 처리간 차이가 나타나지 않았지만 근내지방 및 육질 등급은 T2구에서 각각 5.0 및 3.5로서 가장 높게 나타났다. 특히 육색은 농산부산물 사료 첨가량이 증가할수록 높게 나타났다. 위의 결과로 볼 때 농산부산물 혼합 사료는 질병발생 억제, 육량증가 및 육질개선에 다양한 용도로 사용 가능한 것으로 사료된다.