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Correction of failure in antenna array using matrix pencil technique

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Chinese Physics B 2017年第6期26卷 491-498页

作者： S u khan M k A Rahim Advanced RF & Microwave Research Group Department of Communication Engineering Faculty of Electrical Engineering Universiti Teknologi Malaysia 81310 Skudai Johor Malaysia

In this paper a non-iterative technique is developed for the correction of faulty antenna array based on matrix pencil technique（MPT）. The failure of a sensor in antenna array can damage the radiation power pattern in terms of sidelobes level and nulls. In the developed technique, the radiation pattern of the array is sampled to form discrete power pattern information set. Then this information set can be arranged in the form of Hankel matrix（HM） and execute the singular value decomposition（SVD）. By removing nonprincipal values, we obtain an optimum lower rank estimation of HM. This lower rank matrix corresponds to the corrected pattern. Then the proposed technique is employed to recover the weight excitation and position allocations from the estimated matrix. Numerical simulations confirm the efficiency of the proposed technique, which is compared with the available techniques in terms of sidelobes level and nulls.

关键词： array correction low rank estimation matrix pencil technique singular value decomposition

Synthesis of Nano-sized Barium Titanate Powder by Solid-state Reaction between Barium Carbonate and Titania

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Journal of Materials Science & Technology 2007年第5期23卷 655-658页

作者： u.Manzoor D.k.kim Department of Physics COMSATS Institute of Information TechnologyIslamabadPakistan Department of Materials Science and Engineering Korea Advanced Institute of Science and Technology(KAIST)DaejeonKorea

Size control of BaTiO3 in solid-state reaction between BaCO3 and TiO2 was demonstrated by varying the size of TiO2 and milling conditions of BaCO3. The smaller TiO2 particles had higher surface area, resulting in faster initial reaction. The mechanically milled BaCO3 particles accelerated the diffusion process and decreased the calcinations temperature. It can be deduced from the results that the size control is possible and nano-sized BaTiO3 particles with about 60 nm can be synthesized by using the conventional solid-state reaction between BaCO3 and TiO2.

关键词： Barium tltanate Mechanical milling Solid-state reaction Nano particles

Two macrophages, osteoclasts and microglia: from development to pleiotropy

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Bone Research 2021年第2期9卷 143-152页

作者： Ji-Won Lee In-Hee Lee Tadahiro Iimura sek Won kong Department of Nephrology Transplant Research ProgramBoston Children’s HospitalBostonMA 02115USA Department of Pharmacology Graduate School of Dental MedicineHokkaido UniversitySapporo 060-8586Japan Computational Health Informatics Program Boston Children’s HospitalBostonMA 02115USA Department of Pediatrics Harvard Medical SchoolBostonMA 02115USA

Tissue-resident macrophages are highly specialized to their tissue-specific microenvironments,activated by various inflammatory signals and modulated by genetic and environmental *** and microglia are distinct tissue-resident cells of the macrophage lineage in bone and brain that are responsible for pathological changes in osteoporosis and Alzheimer’s disease(AD),*** is more frequently observed in individuals with AD compared to the prevalence in general *** of AD is often delayed until underlying pathophysiological changes progress and cause irreversible damages in structure and function of *** such earlier diagnosis and intervention of individuals at higher risk would be indispensable to modify clinical *** is the phenomenon that a genetic variant affects multiple traits and the genetic correlation between two traits could suggest a shared molecular *** this review,we discuss that the Pyk2-mediated actin polymerization pathway in osteoclasts and microglia in bone and brain,respectively,is the horizontal pleiotropic mediator of shared risk factors for osteoporosis and AD.

关键词： diagnosis osteoporosis osteoclast

Saddle Point Criteria in Nonsmooth Semi-Infinite Minimax Fractional Programming Problems

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Journal of Systems Science & Complexity 2018年第2期31卷 446-462页

作者： MISHRA S k SINGH Yadvendra VERMA R u Department of Mathematics Banaras Hindu University Varanasi-221005 India. Department of Mathematics Texas State University USA

This paper considers a nonsmooth semi-infinite minimax fractional programming problem（SIMFP） involving locally Lipschitz invex functions. The authors establish necessary optimality conditions for SIMFP. The authors establish the relationship between an optimal solution of SIMFP and saddle point of scalar Lagrange function for SIMFP. Further, the authors study saddle point criteria of a vector Lagrange function defined for SIMFP.

关键词： Generalized convexity Lagrange function nonsmooth programming problems saddlepoint semi-infinite minimax fractional programming problems.

Hybrid Active Contour Mammographic Mass Segmentation and Classification

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Computer Systems Science & Engineering 2022年第3期40卷 823-834页

作者： k.Yuvaraj u.S.Ragupathy Department of Electronics and Instrumentation Engineering Kongu Engineering College PerunduraiErode638060India

This research implements a novel segmentation of mammographic *** methods are proposed,namely,segmentation of mass based on iterative active contour,automatic region growing,and fully automatic mask selectionbased active contour *** the first method,iterative threshold is performed for manual cropped preprocessed image,and active contour is applied *** overcome manual cropping in the second method,an automatic seed selection followed by region growing is *** that the result is only a few images owing to over segmentation,the third method uses a fully automatic active *** of the segmentation techniques are compared with the manual markup by experts,specifically by taking the difference in their mean ***,the difference in the mean value of the third method is 1.0853,which indicates the closeness of the ***,the proposed method is compared with the existing fuzzy C means and level set *** automatic mass segmentation based on active contour technique results in segmentation with high *** using adaptive neuro fuzzy inference system,classification is done and results in a sensitivity of 94.73%,accuracy of 93.93%,and Mathew’s correlation coefficient(MCC)of 0.876.

关键词： Feature optimization hybrid active contour segmentation mass classification mass feature extraction medical image analysis

Thermal Properties of Ni–Cr–Si–B–Fe Based Interlayer Material and Its Application in TLP Bonding of IN 718 Superalloy

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Acta Metallurgica Sinica(English Letters) 2020年第12期33卷 1666-1680页

作者： u.k.Tarai P.S.Robi Sukhomay Pal Department of Mechanical Engineering IIT GuwahatiGuwahati 781039India

A new Ni–Cr–Si–B–Fe fi ller material is prepared for transient liquid-phase(TLP)bonding of Inconel 718 superalloy by mechanical alloying *** melting temperature range of the fi ller material and its activation energy of melting are determined by diff erential scanning calorimetry *** activation energy and melting temperature of the alloy powder decrease with increasing milling *** 718 alloy was joined via TLP by using the newly developed fi ller *** eff ect of TLP bonding temperature and time on microstructural evolution and mechanical properties of the joint was *** distinct microstructural regions were observed in the bonding area:isothermal solidifi cation zone consisting of a single-phase solid solution,diff usion aff ected zone consisting of extensive diff usion-induced precipitates of metallic boride,and unaff ected base *** ultimate shear strength and microhardness of the TLP-bonded joint increase with bonding time and temperature.

关键词： Transient liquid-phase(TLP)bonding kissinger plot Mechanical alloying Inconel 718

Electrochemical determination of an anti-hyperlipidimic drug pitavastatin at electrochemical sensor based on electrochemically pre-treated polymer film modified GCE

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Journal of Pharmaceutical Analysis 2017年第4期7卷 258-264页

作者： umar J.Pandit Gowhar A.Naikoo Mehraj ud Din Sheikh Gulzar A.khan k.k.Raj S.N.Limaye Department of Chemistry Dr. Harisingh Gour UniversitySagarM.P.India Department of Mathematics and Sciences College of Arts and Applied SciencesDofar UniversitySalalahOman

An electrochemically pretreated silver macroporous(Ag MP) multiwalled carbon nanotube modified glassy carbon electrode(PAN-Ag MP-MWCNT-GCE) was fabricated for the selective determination of an antihyperlipidimic drug, pitavastatin(PST). The fabricated electrochemical sensor was characterized by cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS). The fabricated electrode was employed in quantifying and determining PST through differential pulse adsorptive stripping voltammetry(DPAdSV) and CV. The electrode fabrication proceeded with remarkable sensitivity to the determination of PST. The effect of various optimized parameters such as pH, scan rate(ν), accumulation time(t_(acc)), accumulation potential(u_(acc))and loading volumes of Ag MP-MWCNT suspension were investigated to evaluate the performance of synthesized electrochemical sensor and to propose a simple, accurate, rapid and economical procedure for the quantification of PST in pharmaceutical formulations and biological fluids. A linear response of PST concentration in the range 2.0×10^(-7)–1.6×10^(-6)M with low detection(LOD) and quantification(LOQ) limits of 9.66 ± 0.04 nM and 32.25 ± 0.07 nM, respectively, were obtained under these optimized conditions.

关键词： Pitavastatin Electrochemical sensor Adsorptive stripping voltammetry Biological fluids Pharmaceutical formulations

Fecal microbes, short chain fatty acids, and colorectal cancer across racial/ethnic groups

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World Journal of Gastroenterology 2015年第9期21卷 2759-2769页

作者： Christina M Hester Venkatakrishna R Jala Morgan GI Langille Shahid umar k Allen Greiner Bodduluri Haribabu Department of Family Medicine Research Division University of Kansas Medical CenterKansas CityKS 66160United States university of kansas Cancer Center university of kansas Medical Center Kansas CityKS 66160United States James Graham Brown Cancer Center and Department of Microbiology and Immunology University of LouisvilleLouisvilleKY 40202United States Department of Pharmacology Dalhousie UniversityHalifaxNS B3H 4R2Canada Department of Molecular and Integrative Physiology University of Kansas Medical CenterKansas CityKS 66160United States

AIM:To investigate differences in microbes and short chain fatty acid(SCFA) levels in stool samples from Hispanic and non-Hispanic African American,American Indian,and White ***:Stool samples from twenty participants were subjected to analysis for relative levels of viable bacteria and for SCFA ***,the samples were subjected to 16 S r RNA gene pyrosequencing for identification of bacteria present in the *** used a metagenome functional prediction technique to analyze genome copy numbers and estimate the abundance of butyrate kinase in all ***:We found that African Americans had significantly lower levels of acetate,butyrate,and total SCFAs than all other racial/ethnic *** also found that participant microbial profiles differed by racial/ethnic *** Americans had significantly more Firmicutes than Whites,with enriched *** Firmicutes /Bacteroidetes ratio was also significantly higher for African Americans than for Whites(P =0.049).We found Clostridium levels to be significantly and inversely related to total SCFA levels(P =0.019) and we found Bacteroides to be positively associated(P =0.027) and Clostridium to be negatively associated(P =0.012) with levels of *** also identified a correlation between copy number for a butyrate kinase predicted from 16 S r RNA gene abundance and levels of butyrate in ***:The identified differences in gut flora and SCFA levels may relate to colorectal cancer mortality differentials and may be useful as targets for future clinical and behavioral interventions.

关键词： Colorectal cancer Short chain fatty acids Racial/e

The effect of powder size on the mechanical and corrosion properties and the ignition temperature of WE43 alloy prepared by spark plasma sintering

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Journal of Magnesium and Alloys 2021年第4期9卷 1356-1369页

作者： Drahomír Dvorský Jiríkubásek Michaela Roudnická Filip Pruša David Necas Peter Minárik Jitka Stráská Dalibor Vojtech university of Chemistry and Technology Faculty of Chemical TechnologyDepartment of Metals and Corrosion EngineeringTechnická516628 Praha 6–DejvicePragueCzech Republic Institute of Physics Czech Academy of ScienceNa Slovance 1999/218221 Praha 8PragueCzech Republic Department of Physics of Materials Charles UniversityKe Karlovu 5Prague 12116Czech Republic

Powder metallurgy is a powerful method for the preparation of materials with superior *** work aimed to investigate the effect of powder size on the microstructure,mechanical,and corrosion properties of advanced WE43(Mg-4Y-3REE-Zr)alloy prepared by spark plasma sintering(SPS).At the same time,the effect of HF pre-treatment of the powder on the properties of final compacted products is *** powder particles yielded microstructure with more interfaces formed by Y_(2)O_(3),or MgF_(2) and YF_(3).These interfaces work as barriers against corrosion,which greatly improves corrosion *** suggested pre-treatment of powder in HF further reduced the corrosion rate of the compacted *** the contrary,fragile interfaces of YF_(3) decreased mechanical properties as the crack primarily propagates through these *** original powder containing the mixture of all powder fractions exerted the best combination of mechanical *** size has also shown to affect ignition *** highest ignition temperature was measured for the finest powder fraction.

关键词： Powder metallurgy Mechanical properties Corrosion Interface SPS