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Observer Evaluation of a Metal Artifact Reduction Algorithm Applied to Head and Neck Cone Beam Computed Tomographic Images

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INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS 2016年第4期96卷 897-904页

作者： Korpics, Mark Surucu, Murat Mescioglu, Ibrahim Alite, Fiori Block, Alec M. Choi, Mehee Emami, Bahman Harkenrider, Matthew M. Solanki, Abhishek A. Roeske, John C. Loyola Univ Med Ctr Dept Radiat Oncol 2160 S First Ave Maywood IL 60153 USA

Purpose and Objectives: To quantify, through an observer study, the reduction in metal artifacts on cone beam computed tomographic (CBCT) images using a projection-interpolation algorithm, on images containing metal artifacts from dental fillings and implants in patients treated for head and neck (H&N) cancer. Methods and Materials: An interpolation-substitution algorithm was applied to H&N CBCT images containing metal artifacts from dental fillings and implants. Image quality with respect to metal artifacts was evaluated subjectively and objectively. First, 6 independent radiation oncologists were asked to rank randomly sorted blinded images (before and after metal artifact reduction) using a 5-point rating scale (1 = severe artifacts;5 = no artifacts). Second, the standard deviation of different regions of interest (ROI) within each image was calculated and compared with the mean rating scores. Results: The interpolation-substitution technique successfully reduced metal artifacts in 70% of the cases. From a total of 60 images from 15 H&N cancer patients undergoing image guided radiation therapy, the mean rating score on the uncorrected images was 2.3 +/- 1.1, versus 3.3 +/- 1.0 for the corrected images. The mean difference in ranking score between uncorrected and corrected images was 1.0 (95% confidence interval: 0.9-1.2, P<.05). The standard deviation of each ROI significantly decreased after artifact reduction (P<.01). Moreover, a negative correlation between the mean rating score for each image and the standard deviation of the oral cavity and bilateral cheeks was observed. Conclusion: The interpolation-substitution algorithm is efficient and effective for reducing metal artifacts caused by dental fillings and implants on CBCT images, as demonstrated by the statistically significant increase in observer image quality ranking and by the decrease in ROI standard deviation between uncorrected and corrected images. (C) 2016 Elsevier Inc. All rights reserved.

关键词： HEAD & neck cancer diagnosis COMPUTED tomography computer algorithms THREE-dimensional imaging IMAGE quality analysis

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Robust controller design of SGCMG driven by hollow USM

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MICROSYSTEM TECHNOLOGIES-MICRO-AND NANOSYSTEMS-INFORMATION STORAGE AND PROCESSING SYSTEMS 2016年第4期22卷 741-746页

作者： Pan, Song Zhang, Jian-Hui Huang, Wei-Qing Nanjing Univ Aeronaut & Astronaut Coll Aerosp Engn Nanjing 210016 Jiangsu Peoples R China

This work proposes a design for robust control system of a single-gimbal control moment gyro (SGCMG) driven by a hollow ultrasonic motor. Considering the nonlinear characteristic of the whole system, the fuzzy Takage-Sugeno control theory was introduced to achieve a robust control over wide range stability. Based on the proposed control theory, the parameters of feedback control of close loop were determined, and a whole system model has been build for system simulation and robust controller research. The simulation results have shown the effectiveness of the proposed control algorithm. The proposed controller was implemented on an embedded microcontroller unit through C language. On the actual system of SGCMG driven by ultrasonic motor, a sinusoidal signal speed tracking has shown that the speed error less 0.5A degrees/s and the close loop system express a good stability over a referenced speed range of 0.2-72A degrees/s. Step response experiments shown that the system fast response time without overshot. The experiments have verified the proposed robust control algorithm in speed, robustness and stability.

关键词： velocity errors control systems C language systems simulation Robust controllers Control Theory ultrasonic motors computer algorithms non-linear characteristic controller design speed range robust controller design micro-controller unit Systems modelling Robust control

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Image Encryption Algorithm Based on Dynamic DNA Coding and Chen's Hyperchaotic System

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MATHEMATICAL PROBLEMS IN ENGINEERING 2016年第1期2016卷 1-11页

作者： Zhang, Jian Hou, Dezhi Ren, Honge Northeast Forestry Univ Coll Informat & Comp Engn Harbin 150040 Peoples R China

With the development of national information processes, specific image information from secret departments or individuals is often required to be confidentially transmitted. Numerous image encryption methods exist, especially since the initial value sensitivity and other characteristics of chaos theory and chaos theory-based encryption have become increasingly important in recent years. At present, DNA coding constitutes a new research direction of image encryption that uses the four base pairs of DNA code and image pixel values to establish a special correspondence, in order to achieve pixel diffusion. There are eight DNA encoding rules, and current methods of selecting the DNA encoding rules are largely fixed. Thus, the security of encoded data is not high. In this paper, we use the Lorenz chaotic system, Chen's hyperchaotic system, and the DNA encoding combination and present a new image encryption algorithm that can dynamically select eight types of DNA encoding rules and eight types of DNA addition and subtraction rules, with significant improvements in security. Through simulation experiments and histograms, correlations, and NPCR analyses, we have determined that the algorithm possesses numerous desirable features, including good encryption effects and antishear and antinoise performances.

关键词： IMAGE encryption (computer science) computer algorithms CHAOS theory INFORMATION processing SUBTRACTION (Mathematics) INITIAL value problems

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Stochastic optimization model of locomotive assignment to freight trains

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AUTOMATION AND REMOTE CONTROL 2016年第11期77卷 1944-1956页

作者： Ivanov, S. V. Kibzun, A. I. Osokin, A. V. Natl Res Univ Moscow State Aviat Inst Moscow Russia

Consideration was given to the optimization model of assigning the locomotives to the freight trains. The model was formulated in terms of a dynamic problem of stochastic programming with probabilistic constraints. The state variables characterize positions of the locomotives and trains at each time instant. The variables defining the motion of locomotives and their assignment to trains at each time instant play the role of controls. The expectation of the total freight traffic is the criterial function of the problem. A two-stage hybrid algorithm to solve the problem was developed. It combines the coordinatewise search and a genetic algorithm. Results of the numerical experiment were given.

关键词： MATHEMATICAL optimization STOCHASTIC analysis LOCOMOTIVES CONSTRAINT satisfaction (Artificial intelligence) computer algorithms

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Ensemble based collaborative and distributed intrusion detection systems: A survey

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JOURNAL OF NETWORK AND computer APPLICATIONS 2016年 66卷 1-16页

作者： Folino, Gianluigi Sabatino, Pietro ICAR CNR Ist Calcolo & Reti Ad Alte Prestaz Via P Bucci I-87036 Arcavacata Di Rende CS Italy

Modern network intrusion detection systems must be able to handle large and fast changing data, often also taking into account real-time requirements. Ensemble-based data mining algorithms and their distributed implementations are a promising approach to these issues. Therefore, this work presents the current state of the art of the ensemble-based methods used in modern intrusion detection systems, with a particular attention to distributed approaches and implementations. This review also consider supervised and unsupervised data mining algorithms, more suitable to work in an environment that requires the analysis of data streams in real-time. Sharing knowledge across multiple nodes is another of the key points in designing appropriate NIDSs and for this reason, collaborative IDS were also included in this work. Finally, we discuss some open issues and lessons learned from this review, which can help researchers to design more efficient NIDSs. (C) 2016 Elsevier Ltd. All rights reserved.

关键词： Data mining computer algorithms Real-time computing Data analysis Intrusion detection systems (computer security) Ensembles (Mathematics)

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Modified backstepping algorithm for nonlinear systems

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AUTOMATION AND REMOTE CONTROL 2016年第9期77卷 1567-1578页

作者： Furtat, I. B. Tupichin, E. A. Russian Acad Sci Inst Problems Mech Engn St Petersburg Russia ITMO Univ St Petersburg Russia

Based on the backstepping method, this paper proposes a robust control algorithm for nonlinear plants under parametric uncertainty and external bounded disturbances. The algorithm ensures tracking of the plant output to a smooth reference signal with a required accuracy in the steady-state mode. In comparison with the existing analogs, control system implementation requires only one filter of dimension coinciding with the plant relative degree and observers used for calculation of the stabilizing and basic control laws. This feature considerably simplifies the control scheme and calculation of its parameters. And finally, simulation results illustrating the performance of this scheme are given.

关键词： Observers algorithms Stabilising computer algorithms Simulation results Backstepping Reference signals

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Support Vector Machine with Ensemble Tree Kernel for Relation Extraction

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COMPUTATIONAL INTELLIGENCE AND NEUROSCIENCE 2016年第1期2016卷 1-10页

作者： Liu, Xiaoyong Fu, Hui Du, Zhiguo Guangdong Polytech Normal Univ Dept Comp Sci Guangzhou 510665 Guangdong Peoples R China South China Agr Univ Coll Math & Informat Guangzhou 510642 Guangdong Peoples R China

Relation extraction is one of the important research topics in the field of information extraction research. To solve the problem of semantic variation in traditional semisupervised relation extraction algorithm, this paper proposes a novel semisupervised relation extraction algorithm based on ensemble learning (LXRE). The new algorithm mainly uses two kinds of support vector machine classifiers based on tree kernel for integration and integrates the strategy of constrained extension seed set. The new algorithm can weaken the inaccuracy of relation extraction, which is caused by the phenomenon of semantic variation. The numerical experimental research based on two benchmark data sets (PropBank and AIMed) shows that the LXRE algorithm proposed in the paper is superior to other two common relation extraction methods in four evaluation indexes (Precision, Recall, F-measure, and Accuracy). It indicates that the new algorithm has good relation extraction ability compared with others.

关键词： SUPPORT vector machines DATA mining RESEARCH KERNEL (computer software) computer algorithms PROBLEM solving

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Fault tolerant control for plug-and-play interconnected nonlinear systems

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JOURNAL OF THE FRANKLIN INSTITUTE-ENGINEERING AND APPLIED MATHEMATICS 2016年第10期353卷 2199-2217页

作者： Yang, Hao Jiang, Bin Staroswiecki, Marcel Nanjing Univ Aeronaut & Astronaut Coll Automat Engn Nanjing 211106 Jiangsu Peoples R China CNRS USTL ENS Cachan SATIE UniverSud 61 Ave President Wilson F-94235 Cachan France

This paper considers interconnected nonlinear systems with on-line plugging/unplugging of subsystems that are modeled by state-varying and mode-varying switched systems. A modularized method is proposed to design each subsystem's decentralized control law, which together with a new condition on time intervals of plugging/unplugging lead to the stability of the interconnected system. Three plug-and-play based fault tolerant control algorithms are further provided in the presence of coupling faults. The new result allows for the plugging/unplugging without reconfiguring any subsystem's control law and without taking any action on the faulty subsystems. An example of coupled pendulums is taken to illustrate the theoretical results. (C) 2016 The Franklin Institute. Published by Elsevier Ltd. All rights reserved.

关键词： PLUG & play (computer architecture) FAULT-tolerant computing NONLINEAR systems STABILITY theory computer algorithms

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Exploiting Explicit and Implicit Feedback for Personalized Ranking

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MATHEMATICAL PROBLEMS IN ENGINEERING 2016年第1期2016卷 1-11页

作者： Li, Gai Chen, Qiang Shunde Polytech Sch Elect & Informat Engn Shunde 528333 Guangdong Peoples R China Guangdong Univ Educ Dept Comp Sci Guangzhou 510303 Guangdong Peoples R China

The problem of the previous researches on personalized ranking is that they focused on either explicit feedback data or implicit feedback data rather than making full use of the information in the dataset. Until now, nobody has studied personalized ranking algorithmby exploiting both explicit and implicit feedback. In order to overcome the defects of prior researches, a new personalized ranking algorithm (MERR_SVD++) based on the newest xCLiMF model and SVD++ algorithm was proposed, which exploited both explicit and implicit feedback simultaneously and optimized the well-known evaluation metric Expected Reciprocal Rank (ERR). Experimental results on practical datasets showed that our proposed algorithm outperformed existing personalized ranking algorithms over different evaluation metrics and that the running time of MERR SVD++ showed a linear correlation with the number of rating. Because of its high precision and the good expansibility, MERR SVD++ is suitable for processing big data and has wide application prospect in the field of internet information recommendation.

关键词： FEEDBACK control systems DATA analysis INFORMATION theory computer algorithms MATHEMATICAL models

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A graph-based approach for assessing storm-induced coastal changes

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INTERNATIONAL JOURNAL OF REMOTE SENSING 2016年第20期37卷 4854-4873页

作者： Wu, Qiusheng Su, Haibin Sherman, Douglas J. Liu, Hongxing Wozencraft, Jennifer M. Yu, Bailang Chen, Zuoqi SUNY Binghamton Dept Geog Binghamton NY 13902 USA Texas A&M Univ Kingsville Dept Phys & Geosci Kingsville TX USA Univ Alabama Dept Geog Tuscaloosa AL USA Univ Cincinnati Dept Geog Cincinnati OH USA US Army Corp Engineers Kiln MS USA East China Normal Univ Key Lab Geog Informat Sci Minist Educ Shanghai Peoples R China East China Normal Univ Sch Geog Sci Shanghai Peoples R China

Hurricanes and tropical storms are severe threats to coastal properties, settlements, and infrastructure. Airborne light detection and ranging (lidar) surveys conducted before and after storm events allow detailed analysis of coastal geomorphologic and sediment volumetric changes and have been proved very useful in the study of coastal changes. Traditionally, most studies use the pixel-based differencing method to quantify the spatial extent and magnitude of coastal changes based on sequential lidar surveys. This research presents a graph theory-based approach and associated software tools for representing and quantifying storm-induced damages to buildings, beaches and sand dunes, coastal vegetation canopy, and infrastructure. Generation of elevation difference grids, construction of local contour trees, and derivation of semantic properties are key components of the new algorithm for change object detection and extraction. An ontology and taxonomy are proposed to classify change objects into different types of coastal damages in terms of their semantic properties. This method has been successfully applied to assess damages of Hurricane Ike to the Bolivar Peninsula on the Texas Gulf Coast based on pre- and post-storm airborne lidar data and colour infrared aerial photographs.

关键词： STORMS & the environment HURRICANES TROPICAL storms OPTICAL radar LIDAR (Optics) computer algorithms AERIAL photographs

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