• Investigative Magnetic Resonance Imaging
• /
• 제13권1호
• /
• pp.40-46
• /
• 2009

목적 : 기능적 뇌 자기공명영상 (fMRI)과 확산텐서영상(DTI) 합성기법을 이용하여 피질척수로의 여러 부위에서 정량적 특성을 연구하고자 하였다. 대상 및 방법 : 신경학적 이상이 없는 정상인 10명 (남: 8, 여: 2, 평균연령: 30세, 연령분포 : 22 -38세)을 대상으로 하였다. fMRI는 1.5T를 이용하였으며, 손의 쥐기 펴기를 수행하였다. fMRI와 확산텐서섬유로(DTT)의 합성이 가능한 DtiStudio 프로그램을 이용하여 피질척수로를 3차원 영상화하였다. 이때, 시작 관심영역은 2차원 분할 비등방성(fractional anisotropy, FA) 색지도(color map)에서 fMRI의 운동 수행 시 활성부위가 가장 많은 곳으로, 목표 관심영역은 하부 전방 뇌교의 피질척수 부위로 설정하였다. 정량적 분석을 위하여 관심영역을 부채살부터 연수까지 좌우 각각 5곳에 설정하여 분할 비등방성과 현성 확산계수(ADC)를 측정하였다. 결과 : 모든 대상자는 fMRI에서 일차 감각운동 영역이 주로 활성화되었다. 확산텐서 영상에서 피질척수로의 경로는 일차 감각운동 영역부터 연수까지 주행하였다. 피질척수로의 FA 값은 모든 대상자에서 중뇌와 내측 섬유띠의 후지가 타 부위보다 높았다. 결론 : fMRI와 DTT의 합성기법은 피질척수로 상태의 3차원 영상화 및 각 부위에서 FA와 ADC값을 이용한 정량적 분석이 가능하였다. 앞으로, fMRI와 DTT 합성기법은 뇌손상 환자에서 피질척수로의 명확한 상태를 연구하는 데 유용하게 이용될 것으로 사료된다.

• Journal of information and communication convergence engineering
• /
• 제8권6호
• /
• pp.702-708
• /
• 2010

This paper proposes a novel linearization method for Takagi.sugeno (TS) fuzzy model. A T-S fuzzy controller consists of linear controllers based on local linear models and the local linear controllers cannot be designed independently because of overall stability conditions which are usually conservative. To use linear control theories easily for T-S fuzzy system, the linearization of T-S fuzzy model is required. However, The linearization of T-S fuzzy model is difficult to be achieved by using existing linearization methods because fuzzy rules and membership functions are included in T-S fuzzy models. So, a new linearization method is proposed for the T-S fuzzy system based on the idea of T-S fuzzy state transformation. For the T-S fuzzy system linearized with uncertainties, a robust optimal controller with the robustness of sliding model control(SMC) is designed.

• 동아시아식생활학회지
• /
• 제20권4호
• /
• pp.536-542
• /
• 2010

본 연구는 서울 지역 중화 요리점들로부터 탕수육과 튀김유를 각각 수거하여 지방 함량과 지방산 조성, 트랜스 지방산 함량 및 산가를 비교 분석한 후 탕수육 및 튀김유의 품질을 측정하였다. 탕수육 20종 시료의 총 지방 함량은 평균 14.65%로 측정되었으며, 주요 지방산은 평균적으로 linoleic acid($C_{18:2}$)는 38.13%, oleic acid($C_{18:1}$)는 30.07%, palmitic acid ($C_{16:0}$)는 17.14%의 순으로 높은 함량을 차지하였다. 총 불포화지방산은 평균 70.79%, 포화지방산은 평균 23.47%로 측정되었다. 탕수육 시료 중 6번, 7번, 9번, 16번, 17번 시료를 제외하고 linoleic acid, oleic acid, stearic acid의 순으로 많았으며, 이 세 개의 지방산이 85.38~87.27%를 점유하였다. 반면에, 7번, 9번 시료의 지방산 조성을 살펴보면 oleic acid(평균 41.88%), palmitic acid(평균 23.46%), linoleic acid(평균 15.22%) 순으로 높은 함량을 나타냈으며, 16번, 17번 시료의 지방산 조성을 살펴보면 oleic acid(평균 34.83%), linoleic acid(평균 28.68%), palmitic acid(평균 20.21%)의 순으로 높은 함량을 나타냈다. 특히, 6번 시료는 palmitic acid가 40.70%로 높게 함유하고 있었으며, 총 포화지방산 함량은 49.26%, 총 불포화지방산 함량은 50.05%를 나타내었다. 15종의 튀김유의 주요 지방산 조성을 분석한 결과, palmitic acid는 11.65~20.28%, oleic acid는 23.54~26.32%, linoleic acid는 43.82~52.55%, stearic acid는 3.98~5.29%로 주로 구성되어 있었으며, 탕수육 시료와 튀김유 각 100 g당 함유되어 있는 트랜스 지방산의 함량은 0.24 g와 0.98 g 이하로 각각 적은 양을 함유하고 있었다. 또한, 모든 시료는 식품공전상 튀김유의 산가 규격을 초과하지 않는 것으로 나타났다.

• Journal of Korean Neurosurgical Society
• /
• 제55권5호
• /
• pp.267-272
• /
• 2014

Objective : Differentiation of demyelination in white matter from axonal damage can be determined using diffusion tensor imaging (DTI). In this study using meningioma patients an attempt was made to evaluate the relationship between preoperative weakness and the changes of diffusion parameters in the corticospinal tract (CST) using DTI. Methods : Twenty-six patients with meningioma were enrolled in this study. Eleven of them suffered from objective motor weakness and were classified as Group 1. The remaining 15 patients did not present motor weakness and were classified as Group 2. Fiber tractography and CST diffusion parameters were obtained using DTIStudio. The ratios (lesion side mean value/contralateral side mean value) of CST diffusion parameters were compared with 1.0 as a test value using a one-sample t-test. Results : In Group 1, fractional anisotropy (FA), tensor trace (TT), and radial diffusivity (RD, ${\lambda}2$ and ${\lambda}3$) of the CST were significantly different between two hemispheres, but axial diffusivity (AD, ${\lambda}1$) of the CST was not significantly different between two hemispheres. In Group 2, FA and ${\lambda}3$ of CST did not differ significantly between the hemispheres. In Group 2, TT, ${\lambda}1$, and ${\lambda}2$ of CST in the ipsilateral hemisphere were significantly higher than those of the unaffected hemisphere. However, the differences were small. Conclusion : Motor weakness was related to a low FA and high TT resulting from increased RD of the CST fibers. CST diffusion changes in patients with weakness are similar to those for demyelination.

• 한국축산식품학회지
• /
• 제35권3호
• /
• pp.286-292
• /
• 2015

Fatty acid (FA) composition of longissimus dorsi intramuscular fat in Black Yak and Chinese Yellow Cattle were evaluated in 44 Black Yak and 41 Chinese Yellow Cattle of both genders. Interactions of species with gender were observed for total saturated fatty acid (SFA), unsaturated fatty acid (UFA), monounsaturated fatty acid (MUFA), polyunsaturated fatty acid (PUFA), palmitic acid, stearic acid, oleic acid, linolenic acid, arachidonic acid, EPA, and DHA concentrations, as well as PUFA/SFA ratio in the longissimus dorsi (p<0.05). The SFA percentage was greater in yellow cattle than yak in both genders but the species difference in heifers was greater than in steers (p<0.05). Yak had greater UFA, MUFA and PUFA percentages than yellow cattle in both steers and heifers (p<0.05) but the difference between yak and yellow cattle heifers was greater than yak and yellow cattle steers. The percentages of inolenic acid, arachidonic acid, eicosapentaenoic acid, and docosahexaenoic acid; and PUFA/SFA were greater in yak than yellow cattle in both steers and heifers (p<0.05). In addition, the ratio of n-6/n-3 PUFA in yak was lesser than in yellow cattle (p<0.05). These results indicated that FA composition generally differed between yak and yellow cattle but the differences were not the same in heifers as compared to steers. Results also suggested that species differences in FA composition tended to favor Black Yak over Chinese Yellow Cattle, indicating that the longissimus dorsi of Black Yak may have a higher nutritive value than that of Chinese Yellow Cattle and potential for development as a desirable natural product.

• Animal Bioscience
• /
• 제37권5호
• /
• pp.875-882
• /
• 2024

Objective: An experiment was conducted to study the effect of supplementing DL methionine (DL Met) at graded concentrations on performance, carcass variables, immune responses and antioxidant variables in broiler chicken fed folic acid (FA) fortified (4 mg/kg) low-methionine diet. Methods: A basal diet (BD) without supplemental DL Met, but with higher level (4 mg/kg) of FA and a control diet (CD) with the recommended concentration of methionine (Met) were prepared. The BD was supplemented with DL Met at graded concentrations (0%, 10%, 20%, 30%, 40%, and 50% supplemental DL Met of CD). Each diet was fed ad libitum to 10 replicates of 5 broiler male chicks in each from 1 to 42 d of age. Results: Body weight gain (BWG) reduced, and feed conversion ratio (FCR) increased in broilers fed low-Met BD. At 30% and 20% inclusion of DL met, the BWG and FCR, respectively were similar to those fed the CD. Similarly, supplementation of 10% DL Met to the BD significantly increased ready to cook meat yield and breast meat weight, which were similar to those of the CD fed broilers. Lipid peroxidation reduced, the activity of antioxidant enzymes (GSHPx and GSHRx) in serum increased and lymphocyte proliferation increased with increased supplemental DL Met level in the BD. The concentrations of total protein and albumin in serum increased with DL Met supplementation to the BD. Conclusion: Based on the data, it can be concluded that supplemental Met can be reduced to less than 50% in broiler chicken diets (4.40, 3.94, and 3.39 g/kg, respectively in pre-starter, starter and finisher phases) containing 4 mg/kg FA.

• Korean Journal of Radiology
• /
• 제22권7호
• /
• pp.1142-1151
• /
• 2021

Objective: To evaluate microstructural damage in high myopia (HM) patients using 3T diffusion kurtosis imaging (DKI). Materials and Methods: This prospective study included 30 HM patients and 33 age- and sex-matched healthy controls (HCs) with DKI. Kurtosis parameters including kurtosis fractional anisotropy (FA), mean kurtosis (MK), axial kurtosis (AK), and radial kurtosis (RK) as well as diffusion metrics including FA, mean diffusivity, axial diffusivity (AD), and radial diffusivity derived from DKI were obtained. Group differences in these metrics were compared using tract-based spatial statistics. Partial correlation analysis was used to evaluate correlations between microstructural changes and disease duration. Results: Compared to HCs, HM patients showed significantly reduced AK, RK, MK, and FA and significantly increased AD, predominately in the bilateral corticospinal tract, right inferior longitudinal fasciculus, superior longitudinal fasciculus, inferior fronto-occipital fasciculus, and left thalamus (all p < 0.05, threshold-free cluster enhancement corrected). In addition, DKI-derived kurtosis parameters (AK, RK, and MK) had negative correlations (r = -0.448 to -0.376, all p < 0.05) and diffusion parameter (AD) had positive correlations (r = 0.372 to 0.409, all p < 0.05) with disease duration. Conclusion: HM patients showed microstructural alterations in the brain regions responsible for motor conduction and vision-related functions. DKI is useful for detecting white matter abnormalities in HM patients, which might be helpful for exploring and monitoring the pathogenesis of the disease.

• 한국정밀공학회지
• /
• 제28권4호
• /
• pp.391-397
• /
• 2011

Control of interior permanent magnet (IPMSM) is difficult because its nonlinearity and parameter uncertainty. In this paper, a fuzzy c-regression models clustering algorithm which is based on T-S fuzzy is used to model IPMSM with a series linear model and weight them by memberships. Lagrangian of constrained function is built for calculating clustering centers where training output data are considered. Based on these clustering centers, least square method is applied for T-S fuzzy linear model parameters. As a result, IPMSM can be modeled as T-S fuzzy model for T-S fuzzy control of them.

• 충청수학회지
• /
• 제8권1호
• /
• pp.161-166
• /
• 1995

Let (${\Omega}$, ${\Sigma}$, ${\mu}$) be a finite perfect measure space, and let $f:{\Omega}{\rightarrow}X$ be strongly measurable. f is Pettis integrable if and only if there is a sequence ($f_n$) of Pettis integrable functions from ${\Omega}$ into X such that (a) there is a positive increasing function ${\phi}$ defined on [0, ${\infty}$) such that ${\lim}_{t{\rightarrow}{\infty}}\frac{{\phi}(t)}{t}={\infty}$ and sup $f_{\Omega}{\phi}({\mid}x^*f_n{\mid})d{\mu}$ < ${\infty}$ for each $x^*{\in}B_{X*}$,$n{\in}N$, and (b) for each $x^*{\in}X^*$, $lim_{n{\rightarrow}{\infty}}x^*f_n=x^*fa.e.$.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 춘계학술대회논문집D
• /
• pp.751-758
• /
• 2001

Exergy concept is applied to the analysis of part-load performance of gas turbine engine. Exergy is a useful tool to find the source of irreversibility in thermal system. In this study, details of the performance characteristics of a heavy-duty gas turbine, l50MW-class GE 7FA model, are described by theoretical investigations with exergy analysis. Result shows that exergy destruction rate of gas turbine increases with decreased load, which means increase of irreversibility. Also, it is found that variations of IGV angle and amount of cooling air for turbine blades are closely related to the inefficiencies of compressor and turbine, respectively.