Journal of Zhejiang University-Science C-Computers & Electronics最新文献_第5页

Quasi-angle-preserving mesh deformation using the least-squares approach 基于最小二乘法的准保角网格变形

Journal of Zhejiang University-Science C-Computers & Electronics Pub Date : 2014-09-01 DOI: 10.1631/jzus.C1400103

Gang Xu, Lishan Deng, Wenbing Ge, K. Hui, Guozhen Wang, Yi-gang Wang

引用次数: 0

Image anti-aliasing techniques for Internet visual media processing: a review 网络视觉媒体处理中的图像抗混叠技术综述

Journal of Zhejiang University-Science C-Computers & Electronics Pub Date : 2014-09-01 DOI: 10.1631/jzus.C1400100

Xu-dong Jiang, Bin Sheng, Weiyao Lin, Wei Lu, Lizhuang Ma

引用次数: 5

Exploring optimal combination of a file system and an I/O scheduler for underlying solid state disks 探索用于底层固态磁盘的文件系统和I/O调度器的最佳组合

Journal of Zhejiang University-Science C-Computers & Electronics Pub Date : 2014-08-01 DOI: 10.1631/jzus.C1300314

Hui Sun, Xiao-Lin Qin, Chang-sheng Xie

{"title":"Exploring optimal combination of a file system and an I/O scheduler for underlying solid state disks","authors":"Hui Sun, Xiao-Lin Qin, Chang-sheng Xie","doi":"10.1631/jzus.C1300314","DOIUrl":"https://doi.org/10.1631/jzus.C1300314","url":null,"abstract":"Performance and energy consumption of a solid state disk (SSD) highly depend on file systems and I/O schedulers in operating systems. To find an optimal combination of a file system and an I/O scheduler for SSDs, we use a metric called the aggregative indicator (AI), which is the ratio of SSD performance value (e.g., data transfer rate in MB/s or throughput in IOPS) to that of energy consumption for an SSD. This metric aims to evaluate SSD performance per energy consumption and to study the SSD which delivers high performance at low energy consumption in a combination of a file system and an I/O scheduler. We also propose a metric called Cemp to study the changes of energy consumption and mean performance for an Intel SSD (SSD-I) when it provides the largest AI, lowest power, and highest performance, respectively. Using Cemp, we attempt to find the combination of a file system and an I/O scheduler to make SSD-I deliver a smooth change in energy consumption. We employ Filebench as a workload generator to simulate a wide range of workloads (i.e., varmail, fileserver, and webserver), and explore optimal combinations of file systems and I/O schedulers (i.e., optimal values of AI) for tested SSDs under different workloads. Experimental results reveal that the proposed aggregative indicator is comprehensive for exploring the optimal combination of a file system and an I/O scheduler for SSDs, compared with an individual metric.","PeriodicalId":49947,"journal":{"name":"Journal of Zhejiang University-Science C-Computers & Electronics","volume":"15 1","pages":"607 - 621"},"PeriodicalIF":0.0,"publicationDate":"2014-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1631/jzus.C1300314","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67534682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Adaptive contourlet-wavelet iterative shrinkage/thresholding for remote sensing image restoration 自适应contourlet-小波迭代收缩/阈值复原遥感图像

Journal of Zhejiang University-Science C-Computers & Electronics Pub Date : 2014-08-01 DOI: 10.1631/jzus.C1300377

Nu Wen, Shi-Zhi Yang, C. Zhu, Sheng-cheng Cui

引用次数: 2

Designing a location update strategy for free-moving and network-constrained objects with varying velocity 变速度自由运动和网络约束物体的位置更新策略设计

Journal of Zhejiang University-Science C-Computers & Electronics Pub Date : 2014-08-01 DOI: 10.1631/jzus.C1300337

Yuan-Ko Huang, Lien-Fa Lin

{"title":"Designing a location update strategy for free-moving and network-constrained objects with varying velocity","authors":"Yuan-Ko Huang, Lien-Fa Lin","doi":"10.1631/jzus.C1300337","DOIUrl":"https://doi.org/10.1631/jzus.C1300337","url":null,"abstract":"Spatio-temporal databases aim at appropriately managing moving objects so as to support various types of queries. While much research has been conducted on developing query processing techniques, less effort has been made to address the issue of when and how to update location information of moving objects. Previous work shifts the workload of processing updates to each object which usually has limited CPU and battery capacities. This results in a tremendous processing overhead for each moving object. In this paper, we focus on designing efficient update strategies for two important types of moving objects, free-moving objects (FMOs) and network-constrained objects (NCOs), which are classified based on object movement models. For FMOs, we develop a novel update strategy, namely the FMO update strategy (FMOUS), to explicitly indicate a time point at which the object needs to update location information. As each object knows in advance when to update (meaning that it does not have to continuously check), the processing overhead can be greatly reduced. In addition, the FMO update procedure (FMOUP) is designed to efficiently process the updates issued from moving objects. Similarly, for NCOs, we propose the NCO update strategy (NCOUS) and the NCO update procedure (NCOUP) to inform each object when and how to update location information. Extensive experiments are conducted to demonstrate the effectiveness and efficiency of the proposed update strategies.","PeriodicalId":49947,"journal":{"name":"Journal of Zhejiang University-Science C-Computers & Electronics","volume":"15 1","pages":"675 - 686"},"PeriodicalIF":0.0,"publicationDate":"2014-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1631/jzus.C1300337","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67535028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Development of a monocular vision system for robotic drilling 机器人钻孔单目视觉系统的研制

Journal of Zhejiang University-Science C-Computers & Electronics Pub Date : 2014-08-01 DOI: 10.1631/jzus.C1300379

Wei-dong Zhu, Biao Mei, Guo-Rui Yan, Y. Ke

{"title":"Development of a monocular vision system for robotic drilling","authors":"Wei-dong Zhu, Biao Mei, Guo-Rui Yan, Y. Ke","doi":"10.1631/jzus.C1300379","DOIUrl":"https://doi.org/10.1631/jzus.C1300379","url":null,"abstract":"Robotic drilling for aerospace structures demands a high positioning accuracy of the robot, which is usually achieved through error measurement and compensation. In this paper, we report the development of a practical monocular vision system for measurement of the relative error between the drill tool center point (TCP) and the reference hole. First, the principle of relative error measurement with the vision system is explained, followed by a detailed discussion on the hardware components, software components, and system integration. The elliptical contour extraction algorithm is presented for accurate and robust reference hole detection. System calibration is of key importance to the measurement accuracy of a vision system. A new method is proposed for the simultaneous calibration of camera internal parameters and hand-eye relationship with a dedicated calibration board. Extensive measurement experiments have been performed on a robotic drilling system. Experimental results show that the measurement accuracy of the developed vision system is higher than 0.15 mm, which meets the requirement of robotic drilling for aircraft structures.","PeriodicalId":49947,"journal":{"name":"Journal of Zhejiang University-Science C-Computers & Electronics","volume":"15 1","pages":"593 - 606"},"PeriodicalIF":0.0,"publicationDate":"2014-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1631/jzus.C1300379","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67535240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Motion synchronization of dual-cylinder pneumatic servo systems with integration of adaptive robust control and cross-coupling approach 自适应鲁棒控制与交叉耦合相结合的双缸气动伺服系统运动同步

Journal of Zhejiang University-Science C-Computers & Electronics Pub Date : 2014-08-01 DOI: 10.1631/jzus.C1300360

De-yuan Meng, G. Tao, Aimin Li, Wei Li

引用次数: 7

Knowledge modeling based on interval-valued fuzzy rough set and similarity inference: prediction of welding distortion 基于区间模糊粗糙集和相似性推理的知识建模:焊接变形预测

Journal of Zhejiang University-Science C-Computers & Electronics Pub Date : 2014-08-01 DOI: 10.1631/jzus.C1300370

Zhi-qiang Feng, Cun-Gen Liu, Hu Huang

{"title":"Knowledge modeling based on interval-valued fuzzy rough set and similarity inference: prediction of welding distortion","authors":"Zhi-qiang Feng, Cun-Gen Liu, Hu Huang","doi":"10.1631/jzus.C1300370","DOIUrl":"https://doi.org/10.1631/jzus.C1300370","url":null,"abstract":"Knowledge-based modeling is a trend in complex system modeling technology. To extract the process knowledge from an information system, an approach of knowledge modeling based on interval-valued fuzzy rough set is presented in this paper, in which attribute reduction is a key to obtain the simplified knowledge model. Through defining dependency and inclusion functions, algorithms for attribute reduction and rule extraction are obtained. The approximation inference plays an important role in the development of the fuzzy system. To improve the inference mechanism, we provide a method of similarity-based inference in an interval-valued fuzzy environment. Combining the conventional compositional rule of inference with similarity based approximate reasoning, an inference result is deduced via rule translation, similarity matching, relation modification, and projection operation. This approach is applied to the problem of predicting welding distortion in marine structures, and the experimental results validate the effectiveness of the proposed methods of knowledge modeling and similarity-based inference.","PeriodicalId":49947,"journal":{"name":"Journal of Zhejiang University-Science C-Computers & Electronics","volume":"15 1","pages":"636 - 650"},"PeriodicalIF":0.0,"publicationDate":"2014-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1631/jzus.C1300370","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67534986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Volterra filter modeling of a nonlinear discrete-time system based on a ranked differential evolution algorithm 基于分级差分进化算法的非线性离散系统Volterra滤波建模

Journal of Zhejiang University-Science C-Computers & Electronics Pub Date : 2014-08-01 DOI: 10.1631/jzus.C1300350

De-Xuan Zou, Li-qun Gao, Steven Li

引用次数: 5

Automatic recovery from resource exhaustion exceptions by collecting leaked resources 通过收集泄漏的资源，从资源耗尽异常中自动恢复

Journal of Zhejiang University-Science C-Computers & Electronics Pub Date : 2014-08-01 DOI: 10.1631/jzus.C1300352

Ziying Dai, Xiaoguang Mao, Li-qian Chen, Yan Lei

{"title":"Automatic recovery from resource exhaustion exceptions by collecting leaked resources","authors":"Ziying Dai, Xiaoguang Mao, Li-qian Chen, Yan Lei","doi":"10.1631/jzus.C1300352","DOIUrl":"https://doi.org/10.1631/jzus.C1300352","url":null,"abstract":"Despite the availability of garbage collectors, programmers must manually manage non-memory finite system resources such as file descriptors. Resource leaks can gradually consume all available resources and cause programs to raise resource exhaustion exceptions. However, programmers commonly provide no effective recovery approach for resource exhaustion exceptions, which often causes programs to halt without completing their tasks. In this paper, we propose to automatically recover programs from resource exhaustion exceptions caused by resource leaks. We transform programs to catch resource exhaustion exceptions, collect leaked resources, and then retry the failure code. A resource collector is designed to identify leaked resources and safely release them. We implement our approach for Java programs. Experimental results show that our approach can successfully handle resource exhaustion exceptions caused by reported resource leaks and allow programs to complete their tasks with an average execution time increase of 2.52% and negligible bytecode size increase.","PeriodicalId":49947,"journal":{"name":"Journal of Zhejiang University-Science C-Computers & Electronics","volume":"15 1","pages":"622 - 635"},"PeriodicalIF":0.0,"publicationDate":"2014-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1631/jzus.C1300352","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67535350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0