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A Local Contrast Fusion Based 3D Otsu Algorithm for Multilevel Image Segmentation

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IEEE/CAA Journal of Automatica Sinica 2020年第1期7卷 200-213页

作者： Ashish Kumar Bhandari Arunangshu Ghosh Immadisetty Vinod Kumar department of Electronics and Communication engineering National Institute of Technology Patna

To overcome the shortcomings of 1 D and 2 D Otsu’s thresholding techniques, the 3 D Otsu method has been *** all Otsu’s methods, 3 D Otsu technique provides the best threshold values for the multi-level thresholding processes. In this paper, to improve the quality of segmented images, a simple and effective multilevel thresholding method is introduced. The proposed approach focuses on preserving edge detail by computing the 3 D Otsu along the fusion phenomena. The advantages of the presented scheme include higher quality outcomes, better preservation of tiny details and boundaries and reduced execution time with rising threshold levels. The fusion approach depends upon the differences between pixel intensity values within a small local space of an image;it aims to improve localized information after the thresholding process. The fusion of images based on local contrast can improve image segmentation performance by minimizing the loss of local contrast, loss of details and gray-level distributions. Results show that the proposed method yields more promising segmentation results when compared to conventional1 D Otsu, 2 D Otsu and 3 D Otsu methods, as evident from the objective and subjective evaluations.

关键词： 1D Otsu 2D Otsu 3D Otsu image fusion local contrast multi-level image segmentation

Learning a graph-based classifier for fault localization

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Science China(Information Sciences) 2020年第6期63卷 195-216页

作者： Hao ZHONG Hong MEI department of Computer Science and engineering Shanghai Jiao Tong University

Because software emerged, locating software faults has been intensively researched, culminating in various approaches and tools that have been applied in real development. Despite the success of these developments, improved tools are still demanded by programmers. Meanwhile, some programmers are reluctant to use any tools when locating faults in their development. The state-of-the-art situation can be naturally improved by learning how programmers locate faults. The rapid development of open-source software has accumulated many bug fixes. A bug fix is a specific type of comments containing a set of buggy files and their corresponding fixed files, which reveal how programmers repair bugs. Feasibly, an automatic model can learn fault locations from bug fixes, but prior attempts to achieve this vision have been prevented by various technical challenges. For example, most bug fixes are not compilable after checking out, which hinders analyzing bug fixes by most advanced static/dynamic tools. This paper proposes an approach called ClaFa that trains a graph-based fault classifier from bug fixes. ClaFa is built on a recent partial-code tool called Grapa, which enables the analysis of partial programs by the complete code tool called WALA. Once Grapa has built a program dependency graph from a bug fix, ClaFa compares the graph from the buggy code with the graph from the fixed code, locates the buggy nodes, and extracts the various graph features of the buggy and clean nodes. Based on the extraction result, ClaFa trains a classifier that combines Adaboost and decision tree learning. The trained ClaFa can predict whether a node of a program dependency graph is buggy or *** evaluate ClaFa on thousands of buggy files collected from four open-source projects: Aries, Mahout,Derby, and Cassandra. The f-scores of ClaFa achieves are approximately 80% on all projects.

关键词： fault classifier partial code analysis bug fix analysis

Microstructural evolution and mechanical properties of friction stir-welded C71000 copper–nickel alloy and 304 austenitic stainless steel

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International Journal of Minerals,Metallurgy and Materials 2018年第11期25卷 1294-1303页

作者： Hamed Jamshidi Aval department of Materials and Industrial engineering Babol Noshirvani University of Technology

Dissimilar joints comprised of copper–nickel and steel alloys are a challenge for manufacturers in modern industries, as these metals are not thermomechanically or chemically well matched. The present study investigated the effects of tool rotational speed and linear speed on the microstructure and mechanical properties of friction stir-welded C71000 copper–nickel and 340 stainless steel alloys using a tungsten carbide tool with a cylindrical pin. The results indicated that a rotational-to-linear speed ratio of 12.5 r/mm did not cause any macro defects, whereas some tunneling defects and longitudinal cracks were found at other ratios that were lower and higher. Furthermore, chromium carbide was formed on the grain boundaries of the 304 stainless steel near the shoulder zone and inside the joint zone, directing carbon and chromium penetration toward the grain boundaries. Tensile strength and elongation percentages were 84% and 65% of the corresponding values in the copper–nickel base metal, respectively.

关键词： dissimilar friction stir welding copper–nickel alloy austenitic stainless steel microstructure mechanical properties

MINIMIZING A LINEAR FRACTIONAL FUNCTION SUBJECT TO A SYSTEM OF SUP-T EQUATIONS WITH A CONTINUOUS ARCHIMEDEAN TRIANGULAR NORM

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Journal of Systems Science & Complexity 2009年第1期22卷 49-62页

作者： Pingke LI Edward P.Fitts department of Industrial and Systems engineering,North Carolina State University,Raleigh,NC 27695-7906,US Shu-Cherng FANG Edward P.Fitts department of Industrial and Systems engineering,North Carolina State University,Raleigh,NC 27695-7906,USA department of Mathematical Sciences,Tsinghua University,Beijing 100084,China College of Management,Dalian University of Technology,Dalian 116024,China. department of Industrial and Systems engineering North Carolina State University

This paper shows that the problem of minimizing a linear fractional function subject to asystem of sup-T equations with a continuous Archimedean triangular norm T can be reduced to a 0-1linear fractional optimization problem in polynomial ***,parametrization techniques,e.g.,Dinkelbach's algorithm,can be applied by solving a classical set covering problem in each *** reduction can also be performed on the sup-T equation constrained optimization problems withan objective function being monotone in each variable *** method could be extended aswell to the case in which the triangular norm is non-Archimedean.

关键词： Fractional optimization fuzzy relational equations triangular norms.

Enhancing manual P-phase arrival detection and automatic onset time picking in a noisy microseismic data in underground mines

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International Journal of Mining Science and Technology 2018年第4期28卷 683-691页

作者： Mborah Charles Ge Maochen department of Mining and Nuclear engineering Missouri University of Science and Technology

Accurate detection and picking of the P-phase onset time in noisy microseismic data from underground mines remains a big challenge. Reliable P-phase onset time picking is necessary for accurate source location needed for planning and rescue operations in the event of failures. In this paper, a new technique based on the discrete stationary wavelet transform （DSWT）and higher order statist!cs, is proposed for processing noisy data from underground mines. The objectives of this method are to （1） Improve manual detection and tPicking of P-phase onset; and （ii） provide an automatic means of detecting and picking P-phase onset me accurately. The DSWT is first used to filter the signal over several scales. The manual P-phase onset detection and picking are then obtained by computing the signal energy across selected scales with frequency bands that capture the signal of interest. The automatic P-phase onset, on the other hand, is achieved by using skewness- and kurtosis-based criterion applied to selected scales in a time-frequency domain. The method was tested using synthetic and field data from an underground limestone mine. Results were compared with results obtained by using the short-term to long-term average （STA/LTA） ratio and that by Reference Ge et al. （2009）. The results show that the me!hod provides a more reliable estimate of the P-phase onset arrival than the STA]LTA method when the signal to noise ratio is very low. Also, the results obtained from the field data matched accurately with the results from Reference Ge et al. （2009）.

关键词： Manual P-phase detection Automatic onset picking Noisy microseismic data Kurtosis Skewness

Investigation of Anode Striation in 34”VGA Shadow Mask PDP

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Plasma Science and Technology 2007年第4期9卷 474-479页

作者：屠彦姜有燕杨兰兰张雄王保平 department of Electronic engineering Southeast UniversityNanjing 210018China

A macro-cell was used to study the phenomenon of anode striation on a 34 VGA Shadow Mask Plasma Display Panel （SMPDP）. The breakdown process in the sustaining period of the macro-cell was taken by an Intensified Charge Coupled Device（ICCD） with narrow band filters. The mechanism of formation and evolution of the anode striation on SMPDP were investigated. The influence of the width of the electrode, the sustaining voltage, sustaining frequency and the voltage of the shadow mask on the anode striation was also studied. The results showed that the width of the electrodes, the sustaining voltage and frequency had a strong influence on the anode striation. The voltage of the shadow mask, however, hardly affected the anode striation, the firing voltage or the sustaining voltage.

关键词： shadow mask plasma display panel discharge characteristics anode striation

Probabilistic day-ahead simultaneous active/reactive power management in active distribution systems

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Journal of Modern Power Systems and Clean Energy 2019年第6期7卷 1596-1607页

作者： Abouzar SAMIMI department of Electrical engineering Arak University of TechnologyArakIran

Distributed generations(DGs)are main components for active distribution networks(ADNs).Owing to the large number of DGs integrated into distribution levels,it will be essential to schedule active and reactive power resources in ***,energy and reactive power scheduling problems are separately managed in ***,the separate scheduling cannot attain a global optimum scheme in the operation of *** this paper,a probabilistic simultaneous active/reactive scheduling framework is presented for *** order to handle the uncertainties of power generations of renewable-based DGs and upstream grid prices in an efficient framework,a stochastic programming technique is *** stochastic programming can help distribution system operators(DSOs)make operation decisions in front of existing *** proposed coordinated model considers the minimization of the energy and reactive power costs of all distributed resources along with the upstream ***,a new payment index as loss profit value for DG units is introduced and embedded in the *** results based on the 22-bus and IEEE33-bus ADNs validate the effectiveness of the proposed *** obtained results verify that through the proposed stochastic-based power management system,the DSO can effectively schedule all DGs along with its economic targets while considering severe uncertainties.

关键词： Simultaneous active/reactive power scheduling Stochastic programming Uncertainty Loss profit value Distributed generations

Modelling of pressure-strain correlation in compressible turbulent flow

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Acta Mechanica Sinica 2008年第1期24卷 37-43页

作者： Siyuan Huang Song Fu department of engineering Mechanics Tsinghua University100084 Beijing China

Previous studies carried out in the early 1990s conjectured that the main compressible effects could be associated with the dilatational effects of velocity fluctuation. Later, it was shown that the main compressibility effect came from the reduced pressure-strain term due to reduced pressure fluctuations. Although better understanding of the compressible turbulence is generally achieved with the increased DNS and experimental research effort, there are still some discrepancies among these recent findings. Analysis of the DNS and experimental data suggests that some of the discrepancies are apparent if the compressible effect is related to the turbulent Mach number, Mt. From the comparison of two classes of compressible flow, homogenous shear flow and inhomogeneous shear flow （mixing layer）, we found that the effect of compressibility on both classes of shear flow can be characterized in three categories corresponding to three regions of turbulent Mach numbers： the low-Mr, the moderate-Mr and high-Mr regions. In these three regions the effect of compressibility on the growth rate of the turbulent mixing layer thickness is rather different. A simple approach to the reduced pressure-strain effect may not necessarily reduce the mixing-layer growth rate, and may even cause an increase in the growth rate. The present work develops a new second-moment model for the compressible turbulence through the introduction of some blending functions of Mt to account for the compressibility effects on the flow. The model has been successfully applied to the compressible mixing layers.

关键词： Compressible turbulence Reynolds stresses Second-moment closure Turbulent Mach number Mixing layer

Distribution and contamination status of chromium in surface sediments of northern Kaohsiung Harbor, Taiwan

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Journal of Environmental Sciences 2013年第7期25卷 1450-1457页

作者： Cheng-Di Dong Chiu-Wen Chen Chih-Feng Chen department of Marine Environmental engineering "National" Kaohsiung Marine University

Thedistribution, enrichment, accumulation, and potential ecological risk of chromium （Cr） in the surface sediments of northern Kaohsiung Harbor, Taiwan, Chinawere investigated. Sediment samples from ten locations located between the river mouths and harbor entrance of northern Kaohsiung Harborwere collected quarterly in 2011 and characterized for Cr, aluminum,water content, organic matter, total nitrogen, total phosphorous, total grease, and grain size. Results showed that the Cr concentrations varied from 27.0 to361.9 mg/kgwith an average of （113.5 ± 87.0） mg/kg. High Cr concentrationwas observed near the Jen-Gen River mouth. The mean Cr concentrationwas high at 255.5 mg/kg,whichwas at least 2 to 7 times than that of other sites. This might imply significant Cr contribution from upstream receiving tannerieswastewater into the Jen-Gen River. The spatialdistribution of Cr reveals relatively high in the river mouth region, especially in Jen-Gen River, and graduallydiminishes toward the harbor entrance region. This indicates that the major sources of Cr pollution from upstream industrial and municipalwastewatersdischarged along the river bank; and Cr maydriftwith sea current and bedispersed into open sea. Moreover, Cr concentrations correlated closely to the physical-chemical properties of the sediments,which suggested the influence of industrial and municipalwastewatersdischarged from the neighboring industrial parks and river basins. Results from the enrichment factor andgeo-accumulation index analyses imply that the Jen-Gen River sediments can be characterized as moderate enrichment and none to medium accumulation of Cr, respectively. However, results of potential ecological risk index indicate that the sediment has low ecological potential risk. The results can provide valuable information todeveloping future strategies for the management of river mouth and harbor.

关键词： accumulation chromium ecological risk enrichment sediment