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Polarimetric Synthetic Aperture Radar Image Classification by a Hybrid Method

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Tsinghua Science and Technology 2007年第1期12卷 97-104页

作者： kamran ullah Khan 杨建 Department of Electronic Engineering Tsinghua University

Different methods proposed so far for accurate classification of land cover types in polarimetric synthetic aperture radar （SAR） image are data specific and no general method is available. A novel hybrid framework for this classification was developed in this work. A set of effective features derived from the coherence matrix of polarimetric SAR data was proposed. Constituents of the feature set are wavelet, texture, and nonlinear features. The proposed feature set has a strong discrimination power. A neural network was used as the classification engine in a unique way. By exploiting the speed of the conjugate gradient method and the convergence rate of the Levenberg-Marquardt method （near the optimal point）, an overall speed up of the classification procedure was achieved. Principal component analysis （PCA） was used to shrink the dimension of the feature vector without sacrificing much of the classification accuracy. The proposed approach is compared with the maximum likelihood estimator （MLE） based on the complex Wishart distribution and the results show the superiority of the proposed method, with the average classification accuracy by the proposed method （95.4%） higher than that of the MLE （93.77%）. Use of PCA to reduce the dimensionality of the feature vector helps reduce the memory requirements and computational cost, thereby enhancing the speed of the process.

关键词： undecimated discrete wavelet transform (UDWT) neural network principal component analysis (PCA)

糖尿病肺结核与非糖尿病肺结核患者在抗结核治疗前后CT征象演变的对照研究

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糖尿病肺结核与非糖尿病肺结核患者在抗结核治疗前后CT征象演变的...

作者： Asad ullah kamran 大连医科大学

学位级别：硕士

目的：本研究对合并及未合并糖尿病的肺结核患者胸部CT表现进行比较分析，同时对两组患者在抗结核治疗前后的CT表现进行比较和评价。材料与方法：对71例活动期的继发性肺结核患者的胸部CT影像进行观察分析，其中41例患者无糖尿病史... 详细信息

目的：本研究对合并及未合并糖尿病的肺结核患者胸部CT表现进行比较分析，同时对两组患者在抗结核治疗前后的CT表现进行比较和评价。材料与方法：对71例活动期的继发性肺结核患者的胸部CT影像进行观察分析，其中41例患者无糖尿病史，30例患者合并糖尿病。所有患者均在抗结核治疗前后进行胸部CT检查。对两组患者及其抗结核治疗前后的CT表现进行对比分析。结果：41例非糖尿病患者中，有28例可观察到肺部实变征象，其中特征性的CT表现包括：肺段受累（98%），空洞（32%），树芽征（61%），支气管扩张（41%）。治疗前后相比较发现，树芽征和胸腔积液的消失以及纤维化病变的出现提示治疗有效。本组患者在治疗前有10例可观察到磨玻璃密度影，治疗3个月后有6例仍可见，6个月后仅2例可见。治疗前后均可观察到网状影（小叶内间质和小叶间隔增厚），间质结节和纤维化等征象。30例合并糖尿病的肺结核患者中，有23例可观察到肺部实变征象。而且病变不具备肺段受累（27%）的特点，可见多发小空洞形成（30%），树芽征（43%），支气管扩张（30%）。治疗前有5例患者可观察到磨玻璃密度影，治疗3个月后仍有5例可见，6个月后有3例可见。治疗前后均可观察到小叶中心结节，边界模糊结节，网状影（小叶内间质和小叶间隔增厚）、间质结节和纤维化等征象。发生于下叶基底段，上叶前段或右肺中叶等非典型部位的结核灶在两组患者的出现率相同。结论：合并糖尿病与非糖尿病的肺结核患者的胸部CT表现有所不同。合并糖尿病的患者中，结核灶不具备按肺段分布的特点，并且可见多发空洞形成。在随访观察中，空洞缩小,肺实变与树芽征吸收以及纤维化病变的出现提示抗结核治疗有效，但糖尿病性肺结核患者疗效不佳，病灶的吸收消散也较非糖尿病患者更慢。对于肺结核患者而言，约半数患者的痰检呈阴性，因此，CT可为肺结核的诊断和治疗，尤其是糖尿病肺结核的早期干预，提供十分有价值的信息。

关键词：肺结核糖尿病 X线断层摄影抗结核治疗

An alternative splicing variant of mineralocorticoid receptor discovered in preeclampsia tissues and its effect on endothelial dysfunction

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Science China(Life Sciences) 2020年第3期63卷 388-400页

作者： Mengxi Guo Chengliang Zhou Gufeng Xu Lin Tang Yechun Ruan Ying Yu Xianhua Lin Dandan Wu Hao Chen Priscilla Yu Luyang Jin Yinyu Wang Yimei Wu kamran ullah Tanzil Ur Rahman Xinmei Liu Jianzhong Sheng Hsiao-Chang Chan Hefeng Huang Women’s Hospital Zhejiang University School of MedicineHangzhou 310058China International Peace Maternal and Child Health Hospital Shanghai Jiao Tong University School of MedicineShanghai 200030China Epithelial Cell Biology Research Center Faculty of MedicineSchool of Biomedical SciencesThe Chinese University of Hong KongHong KongChina Key Laboratory of Reproductive Genetics Ministry of Education(Zhejiang University)Hangzhou 310058China Department of Pathology and Pathophysiology Zhejiang University School of MedicineHangzhou 310058China Shanghai Key Laboratory of Embryo Original Disease Shanghai 20030China

The pathophysiology of preeclampsia(PE)remains *** spiral artery remodeling dysfunction and PE offspring cardiovascular future development has been a worldwide *** collected placental and umbilical artery samples from normotensive and PE *** receptor(MR)and its alternative splicing variant(ASV)expression and their biological effects on PE were *** MR ASV was found to be highly expressed in all PE samples and slightly expressed in about half of the normotensive samples(umbilical artery,~57.58%;placenta,~36.84%).The MR ASV expression was positively associated with blood pressure in both *** MR ASV protein changed the aldosterone-induced expression pattern of MR target genes related to ion exchanges and cell signaling *** MR ASV can also impair the proliferation,migration,and tube formation ability of endothelial *** findings indicate that MR ASV in PE placenta plays a pathogenic role in PE pathophysiology,especially in endothelial dysfunction,and the existence of the MR ASV in PE umbilical artery provides a new direction in the study of PE offspring with increased risk of cardiovascular diseases.

关键词： preeclampsia mineralocorticoid receptor alternative splicing variant offspring endothelial dysfunction

Monte-Carlo simulation of a stochastic differential equation

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Plasma Science and Technology 2017年第12期19卷 6-14页

作者： Arif ullah Majid KHAN M kamran R KHAN 盛正卯 Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026People's Republic of China Department of Physics Quaid-i-Azam University Islamabad Pakistan Department of Physics Institute of Fusion Theory and SimulationsZhejiang UniversityHangzhou 310027People's Republic of China Department of Physics COMSATS Institute of Information TechnologyChack ShahzadIslamabadPakistan Department of Physics Abdul Wali Khan University23200 MardanKPKPakistan

For solving higher dimensional diffusion equations with an inhomogeneous diffusion coefficient,Monte Carlo（MC） techniques are considered to be more effective than other algorithms, such as finite element method or finite difference method. The inhomogeneity of diffusion coefficient strongly limits the use of different numerical techniques. For better convergence, methods with higher orders have been kept forward to allow MC codes with large step size. The main focus of this work is to look for operators that can produce converging results for large step sizes. As a first step, our comparative analysis has been applied to a general stochastic ***, our formulization is applied to the problem of pitch angle scattering resulting from Coulomb collisions of charge particles in the toroidal devices.

关键词： Monte-Carlo simulation stochastic differential equations toroidal plasmas numerical methods

On the role of optimization algorithms in ownership-preserving data mining

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Frontiers of Information Technology & Electronic Engineering 2018年第2期19卷 151-164页

作者： Muhammad kamran Ehsan ullah MUNIR Department of Computer Science COMSATS Institute of Information Technology

Knowledge extraction from sensitive data often needs collaborative work. Statistical databases are generated from such data and shared among various stakeholders. In this context, the ownership protection of shared data becomes important. Watermarking is emerging to be a very effective tool for imposing ownership rights on various digital data formats. Watermarking of such datasets may bring distortions in the data. Consequently, the extracted knowledge may be inaccurate. These distortions are controlled by the usability constraints, which in turn limit the available bandwidth for watermarking. Large bandwidth ensures robustness; however, it may degrade the quality of the data. Such a situation can be resolved by optimizing the available bandwidth subject to the usability constraints. Optimization techniques, particularly bioinspired techniques, have become a preferred choice for solving such issues during the past few years. In this paper, we investigate the usability of various optimization schemes for identifying the maximum available bandwidth to achieve two objectives：（1） preserving the knowledge stored in the data;（2） maximizing the available bandwidth subject to the usability constraints to achieve maximum robustness. The first objective is achieved with a usability constraint model, which ensures that the knowledge is not compromised as a result of watermark embedding. The second objective is achieved by finding the maximum bandwidth subject to the usability constraints specified in the first objective. The performance of optimization schemes is evaluated using different metrics.

关键词： Information security Optimization Digital fights Watermarking

The role of graveyards in species conservation and beta diversity:a vegetation appraisal of sacred habitats from Bannu,Pakistan

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Journal of Forestry Research 2020年第4期31卷 1147-1158页

作者： Saqib kamran Shujaul Mulk Khan Zeeshan Ahmad Amjad Ur Rahman Majid Iqbal Fazal Manan Zahoor Ul Haq Saif ullah Department of Plant Sciences Quaid-i-Azam UniversityIslamabadPakistan

Graveyards or sacred groves are often places of natural vegetation protected by spiritual believers because of their sacred beliefs and indigenous culture.A study of graveyards was conducted to determine their role in species conservation,community formation,and associated indicators and species composition using multivariate statistical *** was hypothesized that variations in the age of graveyards would give rise to diverse plant communities under the impact of various edaphic and climatic *** ecological techniques were applied to determine various phytosociological *** the data were put in MS Excel for analysis in PCORD and CANOCO softwares for cluster analysis(CA),two-way cluster analysis(TWCA),indicator species analysis and canonical correspondence *** and TWCA through Sorenson distance measurements identified five major graveyard plant communities:(1)FicusBougainvillea-Chenopodium;(2)Acacia-Datura-Convolvulus;(3)Ziziphus-Vitex-Abutilon;(4)Acacia-Lantana-Salsola;and(5)*** such as Capparis decidua,Herniaria hirsuta,Salvadora oliedes and Populus euphratica were only present inside graveyards rather than outside and advocate the role of graveyards in species *** impact of different environmental and climatic variables plus the age of the graveyards were also assessed for comparison of plant communities and their respective indicator *** results indicate that higher chlorine concentration,age of graveyards,low soil electrical conductivity,lower anthropogenic activities,higher nitrogen,calcium and magnesium concentrations in the soil,and sandy soils were the strong environmental variables playing a significant role in the formation of graveyard plant communities,their associated indicators and species distribution *** results could further be utilized to evaluate the role of edaphic and climatic factors,indicator species and conservation management practices at a gr

关键词： Graveyards/Sacred groves Plant communities Multivariate statistical techniques Indicator species Edaphic factors Conservation PCORD software

Design and Optimization of 3D Radial Slot Grain Configuration

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Chinese Journal of Aeronautics 2010年第4期23卷 409-414页

作者： Ali kamran School of Astronautics Beijing University of Aeronautics and Astronautics

Upper stage solid rocket motors （SRMS） for launch vehicles require a highly efficient propulsion system. Grain design proves to be vital in terms of minimizing inert mass by adopting a high volumetric efficiency with minimum possible sliver. In this arti- cle, a methodology has been presented for designing three-dimensional （3D） grain configuration of radial slot for upper stage solid rocket motors. The design process involves parametric modeling of the geometry in computer aided design （CAD） software through dynamic variables that define the complex configuration. Grain bum back is achieved by making new surfaces at each web increment and calculating geometrical properties at each step. Geometrical calculations are based on volume and change-in-volume calculations. Equilibrium pressure method is used to calculate the internal ballistics. Genetic algorithm （GA） has been used as the optimizer because of its robustness and efficient capacity to explore the design space for global optimum solution and eliminate the requirement of an initial guess. Average thrust maximization under design constraints is the objective function.

关键词： solid rocket motors 3D grains radial slot configuration internal ballistics computer aided design heuristic optimization genetic algorithm

An improved porous media model for nuclear reactor analysis

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Nuclear Science and Techniques 2016年第1期27卷 117-140页

作者： Roozbeh Vadi kamran Sepanloo Schools of Nuclear Safety Research and Radiation Protection Nuclear Science and Technology Research InstituteEnd of North Karegar Ave.P.O.Box:14359-836TehranIran

In this study, two modifications are proposed to mitigate drawbacks of the conventional approach of using the ‘‘Porous Media Model''(PMM) for nuclear reactor analysis. In the conventional approach, whole reactor core simplifies to a single porous medium and also, the resistance coefficients that are essential to using this model are constant values. These conditions impose significant errors and restrict the applications of the model for many cases,including accident analysis. In this article, the procedures for calculating the coefficients are modified by introducing a practical algorithm. Using this algorithm will result in obtaining each coefficient as a function of mass flow ***, the method of applying these coefficients to the reactor core is modified by dividing the core into several porous media instead of one. In this method, each porous medium comprises a single fuel assembly. PMM with these two modifications is termed ‘‘multi-region PMM'' in this study. Then, the multi-region PMM is introduced to a new CFD-based thermo-hydraulic code that is specifically devised for combining with neutronic *** CITVAP code, which solves multi-group diffusion equations, is the selected as the neutronic part for this study. The resulting coupled code is used for simulation of natural circulation in a MTR. A new semi-analytic method,based on steady-state CFD analysis is developed to verify the results of this case. Results demonstrate considerable improvement, compared to the conventional approach.

关键词：多孔介质模型模型分析反应器传统方法应用程序流体力学分析稳态计算 PMM

Microstructural Evolution of NiTi47.7Cu6.3 Alloy during Hot Deformation

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Journal of Materials Science & Technology 2011年第10期27卷 951-960页

作者： Amir Etaati kamran Dehghani Mining and Metallurgical Eng.Dept. Amirkabir Univ.Tech.

In the present work, the hot workability and microstructural evolution of ***6.3 （at.%） shape memory alloy were investigated by using wedge-rolling test. The wedge specimens were subjected to hot rolling at the temperatures of 700-1000℃. The microstructural evolutions at the strains of 0.05, 0.15, 0.2, 0.25 and 0.3 were then characterized by optical microscopy and scanning electron microscopy （SEM） as well as energy dispersive spectrometry （EDS） technique. Depending on the deformation temperature and strain, the dynamic recrystallization （DRX） could occur, leading to the refining of the microstructure. At low temperatures of 700 and 800℃ there was no sign of DRX at all studied strains. At these temperatures, the formed fine needle-like precipitates pinned the grain boundaries and prevented them from bulging/migration. By contrast, at higher temperatures of 900 and 1000℃, the DRX took place at the critical strains lower than 0.25 and 0.15, respectively. However, at higher temperatures, strain-induced-boundary-migration （SIBM） mechanism resulted in the formation of DRX grains.

关键词： Deformation Wedge rolling test Dynamic recrystallization Ni-rich Nitinol NiTiCu