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Numerical estimation of choice of the regularization parameter for NMR T2 inversion

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Petroleum science 2016年第2期13卷 237-246页

作者： You-Long Zou Ran-Hong Xie Alon arad state Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum Beijing 102249China shell International Exploration and Production Inc. Houston 77079 TX USA

Nuclear Magnetic inversion is the basis of NMR Resonance （NMR） T2 logging interpretation. The regularization parameter selection of the penalty term directly influences the NMR T2 inversion result. We implemented both norm smoothing and curvature smoothing methods for NMR T2 inversion, and compared the inversion results with respect to the optimal regular- ization parameters （（Xopt） which were selected by the dis- crepancy principle （DP）, generalized cross-validation （GCV）, s-curve, L-curve, and the slope of L-curve methods, respectively. The numerical results indicate that the DP method can lead to an oscillating or oversmoothed solution which is caused by an inaccurately estimated noise level. The （Xopt selected by the L-curve method is occa- sionally small or large which causes an undersmoothed or oversmoothed T2 distribution. The inversion results from GCV, s-curve and the slope of L-curve methods show satisfying inversion results. The slope of the L-curve method with less computation is more suitable for NMR T2 inversion. The inverted T2 distribution from norm smoothing is better than that from curvature smoothing when the noise level is high.

关键词： NMR T2 inversion Tikhonov regularizationVariable substitution Levenberg-Marquardt method Regularization parameter selection

Hematocrit level correlates with lungs resistivity in elderly patients with cardiogenic pulmonary edema

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Journal of Biomedical science and Engineering 2011年第1期4卷 76-81页

作者： Marina arad Avraham Adunsky sharon Zlochiver Ofer Barnea shimon Abboud 不详

Regular monitoring of pulmonary congestion in car-diogenic pulmonary edema (CPE) patients is neces-sary for its adequate management via pharmaceuti-cal treatment. It is well known that the development of CPE is accompanied with an increase in hema-tocrit, plasma protein concentration and colloid os-motic pressure due to the decrease in the plasma volume. In the present study the mean left and right lung resistivity values taken pre- and post treatment with diuretics using a hybrid bio-impedance electri-cal impedance tomography system were correlate to the measured changes in hematocrit level. A marginal significant correlation was found between the abso-lute mean lung resistivity and hematocrit levels (Pearson’s correlation coefficient of R = 0.4, p-value = 0.057). When the change in the mean lung resistivity of a patient was plotted vs. the change in hematocrit readout, a significant linear correlation was found (R = 0.7, p-value = 0.02). These results support the validity of the resistivity measurements using bio-impedance system in monitoring changes of pulmonary edema in CPE patients.

关键词： Bio-impedance Parametric EIT Cardiogenic Pulmonary Edema Hematocrit

在同一经口喂养方式下以色列和美国早产儿满周岁时的吮吸行为比较

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维普期刊数据库

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世界核心医学期刊文摘（儿科学分册） 2005年第8期1卷 8-9页

作者： Bromiker R. arad I. Loughran B. 李开 Department of Neonatology Shaare Zedek Medical Center PO Box 3235 Jerusalem Israel

Background: It has been hypothesized t hat early initiation of oral feeding in premature infants may enhance the matura tion of sucking patterns. Aim: To compare preterm infant sucking characteristics in urban level III neonatal care units in the UsA and Israel. The two hospitals have different practices regarding the introduction of oral feeding. Methods: I nfants were assessed at 34- 35 wk postconceptional age (PCA) and at term. sucki ng parameters were assessed with the Kron’s Nutritive sucking Apparatus. Resul ts: 70 infants (38 Americans and 32 Israelis) participated in the study. Oral fe edings were initiated earlier (32.6 ± 4.3 vs 34.5 ± 1.8 wk PCA, p s were reached earlier (35.4 ± 2.8 vs 36.5 ± 2.5 wk PCA, p sA infants. American preterm infants produced significantly mo re sucks (p suck rate (p sucks per burst ( p shorter interburst width (p sraeli i nfants. At term, American infants produced significant more sucks (p suck rate (p shorter intersuck width (p shorter interburst width (p sraeli infants of the same PCA. Conclusion : Different practices in the care of preterm infants, such as postconceptional a ge at introduction of oral feed ing, may play a role in the development of feeding and feeding organization a t term.

关键词：喂养方式经口新生儿监护病房间隔时间城市医院熟练度

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表现为肥厚型心肌病的糖原贮积病

世界核心医学期刊文摘（心脏病学分册） 2005年第6期1卷 27-28页

作者： arad M. Maron B.J. Gorham J.M. J.G.seidman 郭战宏 Dr.Department of Genetics NRB Harvard Medical School 77 Ave. Louis Pasteur Boston MA 02115 United States

BACKGROUND: Unexplained left ventricular hypertrophy often prompts the diagnosis of hypertrophic cardiomyopathy, a sarcomere-protein gene disorder. Because mutations in the gene for AMP-activated protein kinase γ2(PRKAG2) cause an accumulation of cardiac glycogen and left ventricular hypertrophy that mimics hypertrophic cardiomyopathy, we hypothesized that hypertrophic cardiomyopathy might also be clinically misdiagnosed in patients with other mutations in genes regulating glycogen metabolism. METHODs: Genetic analyses performed in 75 consecutive unrelated patients with hypertrophic cardiomyopathy detected 40 sarcomere-protein mutations. In the remaining 35 patients, PRKAG2, lysosome-associated membrane protein 2(LAMP2), α-galactosidase(GLA), and acid α-1,4-glucosidase(GAA) genes were studied. REsULTs: Gene defects causing Fabry’s disease(GLA) and Pompe’s disease(GAA) were not found, but two LAMP2 and one PRKAG2 mutations were identified in probands with prominent hypertrophy and electrophysiological abnormalities. These results prompted the study of two additional, independent series of patients. Genetic analyses of 20 subjects with massive hypertrophy(left ventricular wall thickness, >30 mm) but without electrophysiological abnormalities revealedmutations in neither LAMP2 nor PRKAG2. Genetic analyses of 24 subjects with increased left ventricular wall thickness and electrocardiograms suggesting ventricular preexcitation revealed four LAMP2 and seven PRKAG2 mutations. Clinical features associated with defects in LAMP2 included male sex, severe hypertrophy, early onset(at 8 to 17 years of age), ventricular preexcitation, and asymptomatic elevations of two serum proteins. CONCLUsIONs: LAMP2 mutations typically cause multisystem glycogen-storage disease(Danon’s disease) but can also present as a primary cardiomyopathy. The glycogen-storage cardiomyopathy produced by LAMP2 or PRKAG2 mutations resembles hypertrophic cardiomyopathy but is distinguished by electrophysiolo

关键词：肥厚型心肌病糖原贮积病肌小节蛋白基因原发性心肌病室壁厚度左室肥厚 α半乳糖苷酶生理异常基因分析基因缺陷

Design of a Proportional-Integral-Derivative Controller for an Automatic Generation Control of Multi-area Power Thermal systems Using Firefly Algorithm

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IEEE/CAA Journal of Automatica sinica 2019年第2期6卷 503-515页

作者： K.Jagatheesan B.Anand sourav samanta Nilanjan Dey Amira s.Ashour Valentina E.Balas the Department of Electrical & Electronics Eng. Mahendra Institute of Eng. & Tech. the Department of Electrical & Electronics Eng. Hindusthan College of Eng. & Tech. the Department of Computer science & Engineering University Institute of Technology The University of Burdwan the Department of Information Technology Techno India College of Technology the Department of Electronics and Electrical Communications Engineering Faculty of Engineering Tanta University the Faculty of Engineering Aurel Vlaicu University of Arad

Essentially, it is significant to supply the consumer with reliable and sufficient power. since, power quality is measured by the consistency in frequency and power flow between control areas. Thus, in a power system operation and control,automatic generation control(AGC) plays a crucial role. In this paper, multi-area(Five areas: area 1, area 2, area 3, area 4 and area 5) reheat thermal power systems are considered with proportional-integral-derivative(PID) controller as a supplementary controller. Each area in the investigated power system is equipped with appropriate governor unit, turbine with reheater unit, generator and speed regulator unit. The PID controller parameters are optimized by considering nature bio-inspired firefly algorithm(FFA). The experimental results demonstrated the comparison of the proposed system performance(FFA-PID)with optimized PID controller based genetic algorithm(GAPID) and particle swarm optimization(PsO) technique(PsOPID) for the same investigated power system. The results proved the efficiency of employing the integral time absolute error(ITAE) cost function with one percent step load perturbation(1 % sLP) in area 1. The proposed system based FFA achieved the least settling time compared to using the GA or the PsO algorithms, while, it attained good results with respect to the peak overshoot/undershoot. In addition, the FFA performance is improved with the increased number of iterations which outperformed the other optimization algorithms based controller.

关键词： Automatic generation control(AGC) firefly algorithm genetic algorithm(GA) particle swarm optimization(PsO) proportional-integral-derivative(PID) controller