检索结果-内蒙古大学图书馆

25th IEEE International Conference on Parallel and Distributed systems, ICPADS 2019

作者： Liu, Yuxiang Gao, Xiaofeng Zheng, Jiaqi Chen, Guihai Shanghai Key Laboratory of Scalable Computing and Systems Department of Computer Science and Engineering Shanghai Jiao Tong University Shanghai China State Key Laboratory for Novel Software Technology Nanjing University Nanjing China

ISBN: (纸本)9781728125831

Software-Defined Networks make it more principled and formal to operate and verify networks, which decouple the control plane and the data plane and introduce flexibility and programmability into the network. The SDN control plane needs to frequently update the data plane. However, the decoupled control and data planes face new challenges. The network is still an asynchronous distributed system in rule updates. If the update operations are not carefully scheduled, it may result in blackhole, congestions, and violate the consistency properties. Motivated by the tightly synchronized SDNs, we proposed TIDERS Algorithm for consistent network updates in 'timed SDNs'-where one node update can be scheduled at specific time. In TIDERS, we use synchronized time technique to achieve fast network updates while guaranteeing consistency properties. We focus on congestion-free in scheduling the update operations. To achieve this, we first set up a flow-based dependency graph and transform it into switch-operation level dependency graph. Based on operation dependency graph, we generate an update schedule and gradually optimize it to finally get a fast update schedule. After that, we conduct a series of simulations comparing our approach with several other methods to evaluate it. © 2019 IEEE.

关键词： Flow graphs

来源：评论

学校读者我要写书评

暂无评论

How faithfully can π be interpreted in SA?

引用

Science China(Information Sciences) 2013年第3期56卷 82-96页

作者： LONG Huan FU YuXi Basic Studies in Computing Science Department of Computer ScienceMOE-MS Key Laboratory for Intelligent Computing and Intelligent SystemsShanghai Jiao Tong University

The π calculus and the safe ambient calculus are two of the widely studied variants of process calculi in the field of concurrency *** former is the most classic model for mobile processes and the latter is well known for its nested ***,the relationship between these two models deserves further *** this paper,we reinvestigate this problem *** first give the strengthened encoding *** we propose the encoding of the synchronous π-calculus into the safe ambients *** encoding scheme is a generalization and improvement of Levi and Sangiorgi’s work when moving from the asynchronous π-calculus to the synchronous π-*** show the merits of the encoding by checking the mentioned criteria.

关键词： encoding expressiveness synchronous π-calculus safe ambients

来源：评论

学校读者我要写书评

暂无评论

Optimizing top-k retrieval:submodularity analysis and search strategies

引用

Frontiers of Computer Science 2016年第3期10卷 477-487页

作者： Chaofeng SHA Keqiang WANG Dell ZHANG Xiaoling WANG Aoying ZHOU School of Computer Science Shanghai Key Laboratory of Intelligent Information ProcessingFudan University Shanghai Key Laboratory of Trustworthy Computing East China Normal University Department of Computer Science and Information Systems BirkbeckUniversity of London

The key issue in top-fc retrieval,finding a set of fc documents(from a large document collection) that can best answer a user's query,is to strike the optimal balance between relevance and *** this paper,we study the top-fc retrieval problem in the framework of facility location analysis and prove the submodularity of that objective function which provides a theoretical approximation guarantee of factor 1--for the(best-first) greedy search ***,we propose a two-stage hybrid search strategy which first obtains a high-quality initial set of top-fc documents via greedy search,and then refines that result set iteratively via local *** on two large TREC benchmark datasets show that our two-stage hybrid search strategy approach can supersede the existing ones effectively and efficiently.

关键词： top-k retrieval diversification submodular function maximization

来源：评论

学校读者我要写书评

暂无评论

PATRON: A Unified Pioneer-Assisted Task RecommendatiON Framework in Realistic Crowdsourcing System 13th

PATRON: A Unified Pioneer-Assisted Task RecommendatiON Frame...

引用

13th Annual International Conference on Combinatorial Optimization and Applications, COCOA 2019

作者： Xia, Yuchen Xu, Zhitian Gao, Xiaofeng Chi, Mo Chen, Guihai Shanghai Key Laboratory of Scalable Computing and Systems Department of Computer Science and Engineering Shanghai Jiao Tong University Shanghai China Tencent Inc. Shenzhen China

ISBN: (纸本)9783030364113

Plenty of previous researches focus on crowdsourcing task recommendation to protect data quality and raise task execution efficiency. However, in real life, most crowdsourcing platforms do not allow duplicate task executions due to the budget constraints, and the recommendations are usually made towards new tasks without prior knowledge due to short task lifespan. Therefore, most previous works are noy applicable due to improper assumptions. In this paper, we propose Pioneer-Assisted Task RecommendatiON (PATRON) framework to generate accurate recommendations without analyzing the tasks’ contents. We select a set of pioneer workers to collect initial knowledge of the new tasks, and adopt the k-medoids clustering algorithm to split the workers into subsets based on the worker similarity. Cluster selection and worker pruning provides accurate and efficient recommendations that satisfies the valid recommendation requirements from requesters. Evaluations conducted based on real datasets collected from Tencent SOHO show the efficiency of our proposed framework on recommendation acceptance rate and recommended worker quality. © 2019, Springer Nature Switzerland AG.

关键词： Crowdsourcing

来源：评论

学校读者我要写书评

暂无评论

An evaluation of vehicular networks with real vehicular GPS traces

引用

Eurasip Journal on Wireless Communications and Networking 2013年第1期2013卷 1-10页

作者： Zhu, Yanmin Chen, Chao Gao, Min Department of Computer Science and Engineering Shanghai Jiao Tong University Shanghai 200240 China Shanghai Key Lab of Scalable Computing and Systems Shanghai 200240 China HKUST Fok Ying Tung Graduate School Guangzhou 510730 China

Vehicular networks have attracted increasing attention from both the academy and industry. Applications of vehicular networks require efficient data communications between vehicles, whose performance is concerned with delivery ratio, delivery delay, and routing cost. The most previous work of routing in vehicular networks assumes oversimplified node mobility when evaluating the performance of vehicular networks, e.g., random mobility or artificial movement traces, which fails to reflect the inherent complexity of real vehicular networks. To understand the achievable performance of vehicular networks under real and complex environments, we first comprehensively analyze the affecting factors that may influence the performance of vehicular networks and then introduce four representative routing algorithms of vehicular networks, i.e., Epidemic, AODV, GPSR, and MaxProp. Next, we develop an NS-2 simulation framework incorporating a large dataset of real taxi GPS traces collected from around 2,600 taxis in shanghai, China. With this framework, we have implemented the four routing protocols. Extensive trace-driven simulations have been performed to explore the achievable performance of real vehicular networks. The impact of the controllable affecting factors is investigated, such as number of nodes, traffic load, packet TTL, transmission range, and propagation model. Simulation results show that a real vehicular network has surprisingly poor data delivery performance under a wide range of network configurations for all the routing protocols. This strongly suggests that the challenging characteristics of vehicular networks, such as unique node mobility, constraints of road topology, need further exploration. © 2013 Liao et al.;licensee Springer.

关键词： Routing protocols

来源：评论

学校读者我要写书评

暂无评论

Tinman: Eliminating confidential mobile data exposure with security oriented offloading 15

Tinman: Eliminating confidential mobile data exposure with s...

引用

10th European Conference on Computer systems, EuroSys 2015

作者： Xia, Yubin Liu, Yutao Tan, Cheng Ma, Mingyang Guan, Haibing Zang, Binyu Chen, Haibo Shanghai Key Laboratory of Scalable Computing and Systems China Institute of Parallel and Distributed Systems Shanghai Jiao Tong University China Department of Computer Science Shanghai Jiao Tong University China

ISBN: (纸本)9781450332385

The wide adoption of smart devices has stimulated a fast shift of security-critical data from desktop to mobile devices. However, recurrent device theft and loss expose mobile devices to various security threats and even physical attacks. This paper presents TinMan, a system that protects confidential data such as web site password and credit card number (we use the term cor to represent these data, which is short for Confidential Record) from being leaked or abused even under device theft. TinMan separates accesses of cor from the rest of the functionalities of an app, by introducing a trusted node to store cor and offloading any code from a mobile device to the trusted node to access cor. This completely eliminates the exposure of cor on the mobile devices. The key challenges to TinMan include deciding when and how to efficiently and transparently offload execution;Tin-Man addresses these challenges with security-oriented offloading with a low-overhead tainting scheme called asymmetric tainting to track accesses to cor to trigger offloading, as well as transparent SSL session injection and TCP payload replacement to offload accesses to cor. We have implemented a prototype of TinMan based on Android and demonstrated how TinMan protects the information of user's bank account and credit card number without modifying the apps. Evaluation results also show that TinMan incurs only a small amount of performance and power overhead. Copyright © 2015 ACM.

关键词： Crime

来源：评论

学校读者我要写书评

暂无评论

VButton: Practical attestation of user-driven operations in mobile apps 18

VButton: Practical attestation of user-driven operations in ...

引用

16th ACM International Conference on Mobile systems, Applications, and Services,MobiSys 2018

作者： Li, Wenhao Luo, Shiyu Sun, Zhichuang Xia, Yubin Lu, Long Chen, Haibo Zang, Binyu Guan, Haibing Institute of Parallel and Distributed Systems Shanghai Jiao Tong University China Shanghai Key Laboratory of Scalable Computing and Systems Shanghai Jiao Tong University China Northeastern University United States

ISBN: (纸本)9781450357203

More and more malicious apps and mobile rootkits are found to perform sensitive operations on behalf of legitimate users without their awareness. Malware does so by either forging user inputs or tricking users into making unintended requests to online service providers. Such malware is hard to detect and generates large revenues for cybercriminals, which is often used for committing ad/click frauds, faking reviews/ratings, promoting people or business on social networks, etc. We find that this class of malware is possible due to the lack of practical and robust means for service providers to verify the authenticity of user-driven operations (i.e., operations supposed to be performed, or explicitly confirmed, by a user). We design and build the VButton system to fill this void. Our system introduces a class of attestation-enabled app UI widgets (called VButton UI). Developers can easily integrate VButton UI in their apps to allow service providers to verify that a user-driven operation triggered by a VButton UI is indeed initiated and intended by a real user. Our system contains an on-device Manager, and a server-side Verifier. Leveraging ARM TrustZone, our system can attest operation authenticity even in the presence of a compromised OS. We have implemented the VButton system on an ARM development board as well as a commercial off-the-shelf smartphone. The evaluation results show that the system incurs negligible overhead. © 2018 Association for computing Machinery.

关键词： Malware

来源：评论

学校读者我要写书评

暂无评论

Correlating mobility with social encounters: distributed localization in sparse mobile networks

引用

Wireless Networks 2015年第1期21卷 201-215页

作者： Zhu, Yanmin Jiang, Ruobing Zhao, Junbo Ni, Lionel M. Department of Computer Science and Engineering Shanghai Jiao Tong University Shanghai China Shanghai Key Laboratory of Scalable Computing and Systems Shanghai China Department of Computer Science and Engineering Hong Kong University of Science and Technology Hong Kong Hong Kong

Most existing connectivity-based localization algorithms require high node density which is unavailable in many large-scale sparse mobile networks. By analyzing large datasets of real user traces from Dartmouth and MIT, we observe that user mobility exhibits high spatiotemporal regularity and, more importantly, that user mobility is strongly correlated with the user’s social encounters (including so called Familiar Strangers). Motivated by these important observations, we propose a distributed localization scheme called SOMA that is particularly suitable for sparse mobile networks. To exploit the correlation between mobility and social encounters, we formulate the localization process as an optimization problem with the objective of maximizing the probability of visiting a sequence of locations when the user witnesses the given set of social encounters at different time. Employing the Hidden Markov Model, we design an efficient algorithm based on dynamic programming for solving the optimization problem. SOMA is fully distributed, in which each user only makes use of the connectivity information with other users. Since different users may have varying levels of mobility regularity, one critical challenge with SOMA is that a user with weak mobility regularity may result in poor localization accuracy. We introduce the concept of mobility irregularity to distinguish users. Then, one optimization is made to SOMA that allows a user with weak mobility regularity to leverage the locations from the users encounters. Experimental results based on large-scale real traces demonstrate that SOMA achieves much smaller localization error than many state-of-the-art localization schemes, but requires it minimal running time. © 2014, Springer Science+Business Media New York.

关键词： Wireless networks

来源：评论

学校读者我要写书评

暂无评论

Mining large-scale GPS streams for connectivity refinement of road maps

引用

Computer Journal 2014年第9期58卷 2109-2119页

作者： Zhu, Yanmin Wang, Yin Forman, George Wei, Hong Shanghai Key Lab of Scalable Computing and Systems Shanghai China Department of Computer Science and Engineering Shanghai Jiao Tong University Shanghai China Facebook Menlo Park United States HP Labs Palo Alto United States

As people increasingly rely on road maps in the digital age, manually maintained maps cannot keep up with the demand for accuracy and freshness, evidenced by the recent iOS map incident and the bidding war for Waze. There are many research works on automatic map inference using GPS data, and some have suggested that Google and Waze automate their map update processes to some degree with user data. However, existing published work focuses on refining road geometry. In reality, connectivity issues at intersections, including missing connections and unmarked turn restrictions, are much more prevalent and also more difficult to infer. In this paper, we report our study on the connectivity issues in the OSM shanghai map using 21 months of GPS data from over $10\,000$ taxis. We first adapt a robust map matching algorithm. Then, we propose simple algorithms for detecting missing intersections, turn restrictions and road closures. Empirical results show that our algorithms of connectivity refinement for road maps are effective. © 2015 The British Computer Society. All rights reserved.

关键词： Global positioning system

来源：评论

学校读者我要写书评

暂无评论

Crowdsourcing sensing to smartphones: A randomized auction approach 23

Crowdsourcing sensing to smartphones: A randomized auction a...

引用

23rd IEEE International Symposium on Quality of Service, IWQoS 2015

作者： Li, Juan Zhu, Yanmin Hua, Yiqun Yu, Jiadi Shanghai Key Lab of Scalable Computing and Systems Shanghai China Department of Computer Science and Engineering Shanghai Jiao Tong University Shanghai China

ISBN: (纸本)9781467371131

Mobile crowdsourcing to smartphones has emerged as a compelling paradigm for collecting sensing data over a vast area for various monitoring applications. It is of paramount importance for mobile crowdsourcing to provide incentive mechanisms. State-of-the-art auction mechanisms for mobile crowdsourcing are deterministic in the sense that given the real costs of the smartphone users, a fixed set of smartphone users are recruited for performing sensing tasks. This leads to serious issues including reduced diversity of sensing devices and starvation of some users. In this paper, we propose an approximate-truthful randomized combinatorial auction mechanism for the social cost minimization problem, which is NP-hard. We design an approximate task allocation algorithm that is near optimal with polynomial-time complexity and use it as a block to construct the whole randomized auction mechanism. We carry out numerical studies and show that our randomized auction mechanism achieves approximate truthfulness, individual rationality, and high computation efficiency. Moreover, the proposed mechanism increases diversity of devices and prevents starvation of some smartphones. © 2015 IEEE.

关键词： Smartphones

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：