We present a demand-driven approach to memory leak detection algorithm based on flow- and context-sensitive pointer analysis. The detection algorithm firstly assumes the presence of a memory leak at some program point...
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We present a demand-driven approach to memory leak detection algorithm based on flow- and context-sensitive pointer analysis. The detection algorithm firstly assumes the presence of a memory leak at some program point and then runs a backward analysis to see if this assumption can be disproved. Our algorithm computes the memory abstraction of programs based on points-to graph resulting from flow- and context-sensitive pointer analysis. We have implemented the algorithm in the SUIF2 compiler infrastructure and used the implementation to analyze a set of C benchmark programs. The experimental results show that the approach has better precision with satisfied scalability as expected.
Network emulation environment is great importance to the research of network protocols, applications and security mechanism. Large-scale network topology generation b one of key technologies to construct network emula...
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Network emulation environment is great importance to the research of network protocols, applications and security mechanism. Large-scale network topology generation b one of key technologies to construct network emulation environment. In this paper, a new large-scale network topology generation framework called LSNTGF is proposed, which divides the network topology into three hierarchies: AS, router and terminal node. It contains the assignment mechanism to bandwidth of each link and IP address of each node. The framework is evaluate by implementation, and the result illustrate it is efficient to network emulation environment for network protocols and security research.
How to preserve causal and totally ordered event delivery is an important issue in real-time serverless DVE(distributed Virtual Environment). However, most of the related works are designed to maintain causal order me...
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How to preserve causal and totally ordered event delivery is an important issue in real-time serverless DVE(distributed Virtual Environment). However, most of the related works are designed to maintain causal order merely or time stamped order with intensive computation and bandwidth overhead. In this paper, we proposed a novel distributed algorithm to maintain the before-and-after relationship between events, both causal and concurrent, of DVE at each individual node. Several simulation experiments are carried out to evaluate the performance of our algorithm and the results demonstrate that the algorithm is effective in preserving causal and totally ordered event delivery and more efficient than the previous algorithms.
Reputation systems provide a promising way to build trust relationships between users in distributed cooperation systems, such as file sharing, streaming, distributed computing and social network, through which a user...
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Reputation systems provide a promising way to build trust relationships between users in distributed cooperation systems, such as file sharing, streaming, distributed computing and social network, through which a user can distinguish good services or users from malicious ones and cooperate with them. However, most reputation models mainly focus on evaluating the qualities of different services in one dimension, but care less about the preferences of different users. This paper proposes a personalized reputation model which provides each user a personalized trust view on others according to his preference. In our approach, we aggregate the users' preferences with collaborative filtering method and qualify it with user similarity which is integrated into the computing of reputation values. The experimental results suggest that our model can resist possible kinds of malicious behaviors efficiently.
This paper presents reuse-aware modulo scheduling to maximizing stream reuse and improving concurrency for stream-level loops running on stream processors. The novelty lies in the development of a new representation f...
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ISBN:
(纸本)9783981080162
This paper presents reuse-aware modulo scheduling to maximizing stream reuse and improving concurrency for stream-level loops running on stream processors. The novelty lies in the development of a new representation for an unrolled and software-pipelined stream-level loop using a set of reuse equations, resulting in simultaneous optimization of two performance objectives for the loop, reuse and concurrency, in a unified framework. We have implemented this work in the compiler developed for our 64-bit FT64 stream processor. Our experimental results obtained on FT64 and by simulation using nine representative stream applications demonstrate the effectiveness of the proposed approach.
Broadcast authentication is a critical security service in wireless sensor networks. A protocol named μTESLA[1] has been proposed to provide efficient authentication service for such networks. However, when applied t...
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Broadcast authentication is a critical security service in wireless sensor networks. A protocol named μTESLA[1] has been proposed to provide efficient authentication service for such networks. However, when applied to applications such as time synchronization and fire alarm in which broadcast messages are sent infrequently, μTESLA encounters problems of wasted key resources and slow message verification. This paper presents a new protocol named GBA (Generalized broadcast authentication), for efficient broadcast authentication in these applications. GBA utilises the one-way key chain mechanism of μTESLA, but modifies the keys and time intervals association, and changes the key disclosure mechanism according to the message transmission model in these applications. The proposed technique can take full use of key resources, and shorten the message verification time to an acceptable level. The analysis and experiments show that GBA is more efficient and practical than μESLA in appli ations with various message transmission models.
Collimated electron and proton beams from the interaction of an ultra-intense laser pulse with a rear hole target are studied by particle-in-cell (PIC) simulation. When an ultra-intense laser pulse irradiates on such ...
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ISBN:
(纸本)9789290833529
Collimated electron and proton beams from the interaction of an ultra-intense laser pulse with a rear hole target are studied by particle-in-cell (PIC) simulation. When an ultra-intense laser pulse irradiates on such a target, the hot electrons from the inner surfaces of the hole expand fast into the hole. However, the electrons at the corners expand slower and are compressed strongly. Then two intense electron jets as well as proton jets are sprayed out from the corners. The jets extend into the hole and focus along the laser propagation axis. The effects of the corner angle on the collimated proton beam are also investigated.
Reconfigurable computing tries to achieve the balance between high efficiency of custom computing and flexibility of general-purpose computing. This paper presents the implementation techniques in LEAP, a coarse-grain...
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Reconfigurable computing tries to achieve the balance between high efficiency of custom computing and flexibility of general-purpose computing. This paper presents the implementation techniques in LEAP, a coarse-grained reconfigurable array, and proposes a speculative execution mechanism for dynamic loop scheduling with the goal of one iteration per cycle and implementation techniques to support decoupling synchronization between the token generator and the collector. This paper also in- troduces the techniques of exploiting both data dependences of intra- and inter-iteration, with the help of two instructions for special data reuses in the loop-carried dependences. The experimental results show that the number of memory accesses reaches on average 3% of an RISC processor simulator with no memory optimization. In a practical image matching application, LEAP architecture achieves about 34 times of speedup in execution cycles, compared with general-purpose processors.
Many proposed P2P networks are based on traditional interconnection topologies. Given a static topology, the maintenance mechanism for node join/departure is critical to designing an efficient P2P network. Kautz graph...
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Many proposed P2P networks are based on traditional interconnection topologies. Given a static topology, the maintenance mechanism for node join/departure is critical to designing an efficient P2P network. Kautz graphs have many good properties such as constant degree, low congestion and optimal diameter. Due to the complexity in topology maintenance, however, to date there have been no effective P2P networks that are proposed based on Kautz graphs with base ~ 2. To address this problem, this paper presents the "distributed Kautz (D-Kautz) graphs", which adapt Kautz graphs to the characteristics of P2P networks. Using the D-Kautz graphs we further propose SKY, the first effective P2P network based on Kautz graphs with arbitrary base. The effectiveness of SKY is demonstrated through analysis and simulations.
The Internet-based Virtual Computing Environment (iVCE) provides on-demand aggregation and autonomic collaboration mechanisms to facilitate the utilization of autonomous and dynamic Internet resources. Load balancing ...
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