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An ensemble method for data stream classification in the presence of concept drift

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信息与电子工程前沿：英文版 2015年第12期16卷 1059-1068页

作者： omid ABBASZADEH Ali AMIRI Ali Reza KHANTEYMOORI Department of Computer Engineering University of Zanjan

One recent area of interest in computer science is data stream management and processing. By ‘data stream', we refer to continuous and rapidly generated packages of data. Specific features of data streams are immense volume, high production rate, limited data processing time, and data concept drift; these features differentiate the data stream from standard types of data. An issue for the data stream is classification of input data. A novel ensemble classifier is proposed in this paper. The classifier uses base classifiers of two weighting functions under different data input conditions. In addition, a new method is used to determine drift, which emphasizes the precision of the algorithm. Another characteristic of the proposed method is removal of different numbers of the base classifiers based on their quality. Implementation of a weighting mechanism to the base classifiers at the decision-making stage is another advantage of the algorithm. This facilitates adaptability when drifts take place, which leads to classifiers with higher efficiency. Furthermore, the proposed method is tested on a set of standard data and the results confirm higher accuracy compared to available ensemble classifiers and single classifiers. In addition, in some cases the proposed classifier is faster and needs less storage space.

关键词： Data stream Classificaion Ensemble classifiers Concept drift

p53 modifications:exquisite decorations ofthe powerful guardian

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Journal of Molecular Cell Biology 2019年第7期11卷 564-577页

作者： Yanqing Liu omid Tavana Wei Gu Institute for Cancer Genetics College of Physicians and SurgeonsColumbia UniversityNew YorkNY 10032USA Department of Pathology and Cell Biology College of Physicians and SurgeonsColumbia UniversityNew YorkNY 10032USA Herbert Irving Comprehensive Cancer Center College of Physicians and SurgeonsColumbia UniversityNew YorkNY 10032USA

The last 40 years have witnessed how p53 rose from a viral binding protein to a central factor in both stress responses and tumor *** exquisite regulation of p53 functions is of vital importance for cell fate *** the multiple layers of mechanisms controlling p53 function,posttranslational modifications (PTMs) represent an efficient and precise *** p53 PTMs include phosphorylation,ubiquitination,acetylation,and ***,other PTMs like sumoylation,neddylation,O-GlcNAcylation,adenosine diphosphate (ADP)-ribosylation,hydroxylation,and p-hydroxybutyrylation are also shown to play various roles in p53 *** independent action or interaction,PTMs affect p53 stability,conformation,localization,and binding *** of the PTM-related pathway is among the major causes of p53-associated developmental disorders or diseases,especially in *** review focuses on the roles of different p53 modification types and shows how these modifications are orchestrated to produce various outcomes by modulating p53 activities or targeted to treat different diseases caused by p53 dysregulation.

关键词： p53 acetylation deacetylation phosphorylation ubiquitination methylation transcriptional regulation

Effects of coarse riblets on air flow structures over a slender delta wing using particle image velocimetry

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Chinese Journal of Aeronautics 2019年第6期32卷 1367-1379页

作者： Mahdi NILI-AHMADABADI omid NEMATOLLAHI Kyung Chun KIM Department of Mechanical Engineering Isfahan University of TechnologyIsfahan 84156-83111Iran School of Mechanical Engineering Pusan National UniversityBusan 609-735Republic of Korea

This research investigates the aerodynamic performance and flow characteristics of a delta wing with 65° sweep angle and with coarse axial riblets,and then compares with that of a smooth-surface delta *** Image Velocimetry(PIV)were utilized to visualize the flow over the wing at 6 cross-sections upright to the wing surface and parallel to the wing span,as well as 3 longitudinal sections on the leading edge,symmetry plane,and a plane between them at Angles of Attack(AOA)=20°and 30°and Re=1.2×10~5,2.4×10~5,and 3.6×10~*** effects of the riblets were studied on the vortices diameter,vortex breakdown location,vortices distance from the wing surface,flow lines pattern nearby the wing,circulation distribution,and *** results show that the textured model has a positive effect on some of the parameters related to drag reduction and lift *** riblets increase the flow momentum near the wing’s upper surface except near the *** also increase the flow momentum behind the wing.

关键词： Aerodynamic performance Coarse riblet Delta wing Flow structures Particle image velocimetry Vortex

Investigation of the effect of nozzle shape on supersonic/hypersonic impactors designed for size discrimination of nanoparticles

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Particuology 2014年第5期12卷 60-68页

作者： Saeideh Saadabadi omid Abouali Homayoon Emdad Goodarz Ahmadi School of Mechanical Engineering Shiraz UniversityShirazIran Department of Aeronautical and Mechanical Engineering Clarkson UniversityPotsdamNY 13699USA

In this study the flow field and the nanoparticle collection efficiency of supersonic/hypersonic impactors with different nozzle shapes were studied using a computational modeling approach. The aim of this study was to develop a nozzle design for supersonic]hypersonic impactors with the smallest possible cut-off size d5o and rather sharp collection efficiency curves. The simulation results show that the changes in the angle and width of a converging nozzle do not alter the cut-off size of the impactor; however, using a conical Laval nozzle with an L]Dn ratio less than or equal to 2 reduced d5o. The effect of using a cap as a focuser in the nozzle of a supersonic/hypersonic impactor was also investigated. The results show that adding a cap in front of the nozzle had a noticeable effect on decreasing the cut-off size of the impactor. Both fiat disks and conical caps were examined, and it was observed that the nozzle with the conical cap had a lower cut-off size.

关键词： Supersonic/hypersonic Impactor Nanoparticle Nozzle

Soil evolution along an alluvial-loess transect in the Herat Plain,western Afghanistan

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Journal of Arid Land 2022年第11期14卷 1317-1330页

作者： Farsila MAHMOUDIAN Alireza KARIMI omid BAYAT Department of Soil Science Faculty of AgricultureHerat UniversityHerat 3001-272806Afghanistan Department of Soil Science Faculty of AgricultureFerdowsi University of MashhadMashhad ***Iran

Afghanistan is located in the Eurasian loess belt,however,there is little information on the soils in the *** has covered the Herat Plain in western Herat City,*** the diversity of landform and parent material,there is no information on the soil and landform evolution in this *** objectives of this study were to identify the soils along a transect of different landforms in the Herat Plain and determine the role of geomorphic processes on the soil and landform *** pedons from an alluvial fan,the depression between alluvial fan and piedmont plain,saline and non-saline piedmont plains,and the flood plain of the Hariroud River,were ***,the physical-chemical properties,mineralogy,and micromorphology of the samples were *** showed that the soil parent material in the piedmont plain is loess,whereas,in the flood plain it is a combination of loess and river alluvial ***,lessivage,salinization,and gleization are the most important pedogenic *** calcification and lessivage appear to be the result of a wetter climate during the late Quaternary,whereas the present topography causes the gleization and *** coatings on carbonate nodules and iron nodules are abundant pedofeatures in the Btk(argillic-calcic)*** oxides nodules are common in the soils of the flood *** formation of palygorskite in both alluvial-and loess-derived soils implies the onset of aridity and the trend of increase in environmental aridity in the *** seems that after the formation of a well developed paleosol on the alluvial fan in a more humid climate in the past,the piedmont plain has been covered by loess deposits,and the calcification,gleization,and salinization cause the formation of weakly developed surficial *** study highlights the role of the late Quaternary climatic changes on the evolution of landforms and soils in western Afghanistan.

关键词： alluvial fan loess-derived soils paleosol gleization Hariroud River

The application of ResU-net and OBIA for landslide detection from multi-temporal Sentinel-2 images

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Big Earth Data 2023年第4期7卷 961-985页

作者： omid Ghorbanzadeh Khalil Gholamnia Pedram Ghamisi alnstitute of Advanced Research in Artificial Intelligence(IARAl) ViennaAustria Department of Remote Sensing and GIS University of TabrizTabrizIran Machine Learning Group Helmholtz-Zentrum Dresden-RossendorfHelmholtz Institute Freiberg for Resource TechnologyFreibergGermany

Landslide detection is a hot topic in the remote sensing community,particularly with the current rapid growth in volume(and variety)of Earth observation data and the substantial progress of computer *** learning algorithms,especially fully convolutional networks(FCNs),and variations like the ResU-Net have been used recently as rapid and automatic landslide detection *** FCNs have shown cutting-edge results in automatic landslide detection,accuracy can be improved by adding prior knowledge through possible *** study evaluates a rulebased object-based image analysis(OBIA)approach built on probabilities resulting from the ResU-Net model for landslide *** train the ResU-Net model using a landslide dataset comprising landslide inventories from various geographic regions,including our study area and test the testing area not used for *** the OBIA stage,we frst calculate land cover and image difference indices for pre-and post-landslide multi-temporal ***,we use the generated indices and the resulting ResU-Net probabilities for image segmentation;the extracted landslide object candidates are then optimized using rule-based *** the result validation section,the landslide detection of the proposed integration of the ResU-Net with a rule-based classification of OBIA is compared with that of the ResU-Net *** proposed approach improves the mean intersection-over-union of the resulting map from the ResU-Net by more than 22%.

关键词： Deep learning(DL) Eastern Iburi Japan European Space Agency(ESA) Fully Convolutional Networks(FCNs) object-based image analysis(OBIA) rapid landslide mapping ResUnet Sentinel-2

Neural network based approach for time to crash prediction to cope with software aging

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Journal of Systems Engineering and Electronics 2015年第2期26卷 407-414页

作者： Moona Yakhchi Javier Alonso Mahdi Fazeli Amir akhavan Bitaraf Ahmad Patooghy School of Computer Science Institute for Research in Fundamental Sciences (IPM) Institute of Advanced Studies on Cybersecurity University of Leon Department of Computer Engineering Iran University of Technology

Recent studies have shown that software is one of the main reasons for computer systems unavailability. A growing ac- cumulation of software errors with time causes a phenomenon called software aging. This phenomenon can result in system per- formance degradation and eventually system hang/crash. To cope with software aging, software rejuvenation has been proposed. Software rejuvenation is a proactive technique which leads to re- moving the accumulated software errors by stopping the system, cleaning up its internal state, and resuming its normal operation. One of the main challenges of software rejuvenation is accurately predicting the time to crash due to aging factors such as me- mory leaks. In this paper, different machine learning techniques are compared to accurately predict the software time to crash un- der different aging scenarios. Finally, by comparing the accuracy of different techniques, it can be concluded that the multilayer per- ceptron neural network has the highest prediction accuracy among all techniques studied.

关键词： software reliability software rejuvenation machine learning

Electrochemical Behavior of Passive Films Formed on the Surface of Coarse-,Fine-and Ultra-fine-Grained AA1050 Based on a Modified PDM

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Acta Metallurgica Sinica(English Letters) 2016年第7期29卷 629-637页

作者： Seyed omid Gashti Arash Fattah-alhosseini Yousef Mazaheri Department of Materials Engineering Bu-Ali Sina University

Electrochemical impedance spectroscopy （EIS） and Mott-Schottky analysis were carried out to evaluate the electrochemical behavior of the passive films formed on the surface of coarse-grained （CG）, fine-grained （FG） and ultrafine-grained （UFG） 1050 A1 alloy （AA1050） samples in alkaline media （pH value of 8.0） based on a modification of point defect model （PDM）. The EIS results revealed that the polarization resistance increased from about 22.71-120.33 kΩ cm2 for UFG sample when compared to CG sample （annealed sample）. The semiconductor properties of the passive films formed on CG, FG and UFG AA1050 samples in the test solution were investigated by employing Mott-Schottky analysis in conjunction with PDM. The results indicated that donor densities were in the range of 2.19 × 1021-0.61 × 1021 cm-3 and decreased with grain refinement. Finally, all electrochemical tests showed that the electrochemical behavior of AA1050 alloy was improved by decreasing the grain size, mainly due to the formation of thicker and less defective oxide films.

关键词： AA1050 alloy Grain refinement Ultra-fine grain (UFG) Passive film Mott-Schottky

Mode-conversion-based silicon photonic modulator loaded by a combination of lateral and interleaved p-n junctions

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Photonics Research 2021年第4期9卷 471-476页

作者： omid Jafari Sasan Zhalehpour Wei Shi and Sophie LaRochelle Centre d’optique photonique et laser(COPL)UniversitéLavalQuébec CityQuébecCanada Canada Research Center Huawei Technologies CanadaOttawaOntarioCanada

We experimentally demonstrate a silicon photonic modulator that can be loaded with a combination of lateral and interleaved p-n junctions to enhance its phase *** use an asymmetric Bragg grating to introduce mode conversion in the active area,allowing the modulator to operate in reflection without introducing additional on-chip *** a compact footprint(phase shifter length of 290μm),the modulator demonstrates a modulation speed up to 45 Gb/s with a bit error rate below the 7% forward-error-correction(FEC)threshold(up to 55 Gb/s with 20% FEC),and a low power consumption of 226 fJ/bit.

关键词： Gb/s modulator junctions