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Now showing items 81 - 96 of 569

  • Building Semantic Peer-to-Peer Networks upon CAN

    Jiantao Song, Yong Zhang, Chaofeng Sha   Hong Zhu  

    Existing decentralized architectures for peer-to-peer (P2P) networks can be generally partitioned into two categories: unstructured (such as Gnutella) and structured (such as CAN, Chord, Pastry and Tapestry). Based on Content Addressable Networks (CAN), we propose a hybrid scheme for building Semantic Peer-to-peer Networks (SPNs) where semantically related nodes are connected to each other. The entire peer-to-peer overlay networks are overlapped by many SPNs and all these SPNs are logically organized into a hierarchy. Then we provide a searching algorithm to focus query propagation only in appropriate SPNs. As a result, the nodes visited for a lookup can be reduced by several orders of magnitude compared to Gnutella.
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  • Scenario Analysis in an Automated Tool for Requirements Engineering

    Hong Zhu   Lingzi Jin  

    A scenario is a set of situations of common characteristics that might reasonably occur in the use of a system. It is widely recognised that scenario analysis can play a significant role in requirements acquisition, modelling and analysis. However, for a complicated software system, there may be a great number of scenarios. Synthesising a requirements definition from a set of scenarios and managing the consistency and the completeness of a set of scenarios are difficult and demand automated tool support. This paper presents an automated tool for scenario-driven requirements engineering where scenario analysis plays the central role. It is shown that a scenario can be described by three views of data flow, entity relationship and state transition models by slight extensions of classic data flow, entity relationship and state transition diagrams. The notions of consistency and completeness of a set of scenarios are formally defined in graph theory terminology and automatically checked by the tool. The tool supports automatic validation of requirements definitions by analysing the consistency between a set of scenarios and requirements models. It also supports automatic synthesis of requirements models from a set of scenarios. Its utility and usefulness are demonstrated by a non-trivial example in the paper. Case studies of the tools an also presented
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  • Money Conservation via Atomicity in Fair Off-Line E-Cash

    Shouhuai Xu, Moti Yung, Gendu Zhang   Hong Zhu  

    Atomicity and fault tolerance issues are important and typically open questions for implementing a complete payment scheme. The notion of “fair off-line e-cash” (FOLC) was originally suggested as a tool for crime prevention. This paper shows that FOLC schemes not just enable better control of e-cash when things go wrong due to “criminal suspicion” and other “regulatory/legal” issues, but it can also assure atomicity which takes care of conservation of money in case of failures during transaction runtime. The added protocols are very efficient and quite simple to implement. This kind of piggybacking atomicity control over “anonymity revocation” makes good sense as both actions are done by off-line invocation of the same trustees (TTPs). The resulting solution is a comprehensive yet efficient solution to money conservation in electronic cash transactions based on FOLC schemes. The adopted recovery approach makes the involved participants (customer, bank, merchant) sure that they can “re-think” the transactions when things go wrong, implying the atomicity of the transactions. We also take an optimistic approach achieving fair exchange costing only 2-round of communicational complexity (trivially the lower bound) with no additional TTP involvement since FOLC already employs such a party.
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  • Greedy Construction of 2-Approximation Minimum Manhattan Network

    Zeyu Guo, He Sun   Hong Zhu  

    Given a set T of n points in , a Manhattan Network G is a network with all its edges horizontal or vertical segments, such that for all p,q ∈ T, in G there exists a path (named a Manhattan path) of the length exactly the Manhattan distance between p and q. The Minimum Manhattan Network problem is to find a Manhattan network of the minimum length, i.e., the total length of the segments of the network is to be minimized. In this paper we present a 2-approximation algorithm with time complexity O(nlogn), which improves the 2-approximation algorithm with time complexity O(n2). Moreover, compared with other 2-approximation algorithms employing linear programming or dynamic programming technique, it was first discovered that only greedy strategy suffices to get 2-approximation network.
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  • Acidic resin-catalysed conversion of fructose into furan derivatives in low boiling point solvents

    Hong Zhu   Quan Cao   Chunhu Li   Xindong Mu  

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  • A methodology of testing high-level Petri nets

    Hong Zhu   Xudong He  

    Petri nets have been extensively used in the modelling and analysis of concurrent and distributed systems. The verification and validation of Petri nets are of particular importance in the development of concurrent and distributed systems. As a complement to formal analysis techniques, testing has been proven to be effective in detecting system errors and is easy to apply. An open problem is how to test Petri nets systematically, effectively and efficiently. An approach to solve this problem is to develop test criteria so that test adequacy can be measured objectively and test cases can be generated efficiently, even automatically. We present a methodology of testing high-level Petri nets based on our general theory of testing concurrent software systems. Four types of testing strategies are investigated, which include state-oriented testing, transition-oriented testing, flow-oriented testing and specification-oriented testing. For each strategy, a set of schemes to observe and record testing results and a set of coverage criteria to measure test adequacy are defined. The subsumption relationships and extraction relationships among the proposed testing methods are systematically investigated and formally proved
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  • Liquid crystal display and manufacturing method thereof

    A liquid crystal display (LCD) and a manufacturing method thereof. The LCD comprises a color filter substrate, an array substrate disposed opposite to the color filter substrate, and a liquid crystal layer sealed between the two substrates, wherein a conductive nano-particle is introduced between the two substrates.
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  • Preparation of chitosan-based flocculant for high density waste drilling mud solid–liquid separation

    Hong Zhu   Haiyun Sun   Fanghui Wang   Jing Zou   Jiantao Fan  

    High performance flocculant was prepared by chitosan (CS), ethacryloyloxyethyl trimethyl ammonium chloride (DMC), and acrylamide (AM). The optimum preparation conditions were determined by orthogonal test of four factors and three levels. The different factors affecting the flocculating ability of the prepared flocculants for waste drilling mud were studied, and optimal synthesis conditions were established: polymerization temperature was 60, reaction time was 4 h, DMC was 3 mL, w(AM) : w(CS) was 4, and the initiator was 0.4% of AM (wt %). The prepared CS-AM-DMC copolymer was characterized by Fourier Transform Infrared Spectroscopy (FTIR), scanning electron microscopy (SEM), and gel permeation chromatography (GPC). The results showed that AM, DMC were grafted to CS successfully. The solid-liquid separation properties were also investigated, and the prepared flocculant showed great advantages than commercial products for high density waste drilling mud use. copy 2012 Wiley Periodicals, Inc.
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  • Why are hippocampal CA1 neurons vulnerable but motor cortex neurons resistant to transient ischemia?

    Hong Zhu   Tanihiro Yoshimoto   Shinobu Imajo-Ohmi   Maryia Dazortsava   Arumugam Mathivanan and Tetsumori Yamashima  

    J. Neurochem. (2012) 120, 574–585.
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  • Why are hippocampal CA1 neurons vulnerable but motor cortex neurons resistant to transient ischemia?

    Hong Zhu   Tanihiro Yoshimoto   Shinobu Imajo-Ohmi   Maryia Dazortsava   Arumugam Mathivanan   Tetsumori Yamashima  

    It is well-known that heat-shock protein 70.1 (Hsp70.1), a major protein of the human Hsp70 family, plays cytoprotective roles by both its chaperone function and stabilization of lysosomal membranes. Recently, we found that calpain-mediated cleavage of carbonylated Hsp70.1 in the hippocampal cornu Ammonis1 (CA1) contributes to neuronal death after transient global ischemia. This study aims to elucidate the differential neuronal vulnerability between the motor cortex and CA1 sector against ischemia/reperfusion. Fluoro-Jade B staining and terminal deoxynucleotidyl transferase-mediated dUTP-nick-end-labeling analysis of the monkey brain undergoing 20 min whole brain ischemia followed by reperfusion, showed that the motor cortex is significantly resistant to the ischemic insult compared with CA1. Up-regulation of Hsp70.1 but absence of its cleavage by calpain facilitated its binding with NF-kappa B p65/I kappa B alpha complex to minimize NF-kappa B p65 activation, which contributed to a neuroprotection in the motor cortex. In contrast, because activated mu-calpain cleaved carbonylated Hsp70.1 in CA1, the resultant Hsp70.1 dysfunction not only destabilized lysosomal membrane but also induced a sustained activation of NF-kappa B p65, both of which resulted in delayed neuronal death. We propose that the cascades underlying lysosomal stabilization and regulating NF-kappa B activation by Hsp70.1 may influence neuronal survival/death after the ischemia/reperfusion.
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  • Preparation of chitosan-based flocculant for high density waste drilling mud solid-liquid separation

    Hong Zhu   Haiyun Sun   Fanghui Wang   Jing Zou and Jiantao Fan  

    High performance flocculant was prepared by chitosan (CS), ethacryloyloxyethyl trimethyl ammonium chloride (DMC), and acrylamide (AM). The optimum preparation conditions were determined by orthogonal test of four factors and three levels. The different factors affecting the flocculating ability of the prepared flocculants for waste drilling mud were studied, and optimal synthesis conditions were established: polymerization temperature was 60, reaction time was 4 h, DMC was 3 mL, w(AM) : w(CS) was 4, and the initiator was 0.4% of AM (wt %). The prepared CS–AM–DMC copolymer was characterized by Fourier Transform Infrared Spectroscopy (FTIR), scanning electron microscopy (SEM), and gel permeation chromatography (GPC). The results showed that AM, DMC were grafted to CS successfully. The solid–liquid separation properties were also investigated, and the prepared flocculant showed great advantages than commercial products for high density waste drilling mud use.
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  • Formal Specification of Agent Behaviour through Environment Scenarios

    Hong Zhu  

    Scenarios are typical situations that may occur in the operation of a software system. Scenario analysis plays an important role in software requirements analysis and design. This paper introduces a formal notation for the specification of scenarios in agent-based systems. The autonomous and collaborative behavior of an agent can be formally specified by a set of rules describing its activity in various scenarios. The power of the approach is illustrated by the formal specification of Maes’personal assistant agent Maxims. The paper also shows that agents’ social behavior, such as speech act, can also be formally specified as scenario-reaction rules.
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  • Magnetic head design having reduced susceptibility to electrostatic discharge from media surfaces

    Methods and structures for the fabrication of a thin film, longitudinal and perpendicular recording heads are disclosed. The heads comprise a plurality of embedded static dissipative layers that extend a few nanometers from the air bearing surface. These extended layers are first to contact the magnetic media surface and drain any electric charge buildup before a damaging discharge occurs with read or write head components. The embedded static dissipative layers are particularly useful for use in heads utilizing thermal fly height control systems, which tend to increase the probability of damaging electrical discharge through critical head components.
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  • Preparation of BST ferroelectric thin film by metal organic decomposition for infrared sensor

    Hong Zhu   Jianmin Miao   Minoru Noda   Masanori Okuyama  

    Barium strontium titanate (Ba 1-xSr xTiO 3 ) ferroelectric thin films have been prepared by metal organic decomposition (MOD) on Pt/Ti/SiO 2/Si and on micromachined wafer with an aim to fabricate dielectric bolometer type infrared (IR) sensor. The XRD pattern and D-V hysteresis curve of the film have been measured in order to investigate the effects of the final annealing temperature and annealing time on the property of the film. The results show that the films annealed at 700degC or 800degC all have good perovskite structure, while the film annealed at 800degC has better ferroelectric loops. Films annealed at 800degC with different annealing time from 5 to 60 min show a similar perovskite structure, among which films annealed at 30 and 60 min condition have the better ferroelectric loops. Temperature coefficient of dielectric constant (TCD) of the MOD made BST thin film on micromachined substrate is about 1%/K. The uniformity of the BST film on micromachined Si wafer also has been confirmed to be good enough for operation of sensor array. Chopperless operation has been attained and infrared response evaluation of the fabricated sensor also has been carried out with R v of 0.4 kV/W and D* of 1.0times10 8 cm Hz 1/2/W, respectively
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  • Non-metric Multicommodity and Multilevel Facility Location

    Rudolf Fleischer, Jian Li, Shijun Tian   Hong Zhu  

    We give logarithmic approximation algorithms for the non-metric uncapacitated multicommodity and multilevel facility location problems. The former algorithms are optimal up to a constant factor, the latter algorithm is far away from the lower bound, but it is the first algorithm to solve the general multilevel problem. To solve the multicommodity problem, we also define a new problem, the friendly tour operator problem, which we approximate by a greedy algorithm.
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  • Frequency Allocation Problems for Linear Cellular Networks

    Joseph Wun-Tat Chan, Francis Y. L. Chin, Deshi Ye, Yong Zhang   Hong Zhu  

    We study the online frequency allocation problem for wireless linear (highway) cellular networks, where the geographical coverage area is divided into cells aligned in a line. Calls arrive over time and are served by assigning frequencies to them, and no two calls emanating from the same cell or neighboring cells are assigned the same frequency. The objective is to minimize the span of frequencies used. In this paper we consider the problem with or without the assumption that calls have infinite duration. If there is the assumption, we propose an algorithm with absolute competitive ratio of 3/2 and asymptotic competitive ratio of 1.382. The lower bounds are also given: the absolute one is 3/2 and the asymptotic one is 4/3. Thus, our algorithm with absolute ratio of 3/2 is best possible. We also prove that the Greedy algorithm is 3/2-competitive in both the absolute and asymptotic cases. For the problem without the assumption, i.e. calls may terminate at arbitrary time, we give the lower bounds for the competitive ratios: the absolute one is 5/3 and the asymptotic one is 14/9. We propose an optimal online algorithm with both competitive ratio of 5/3, which is better than the Greedy algorithm, with both competitive ratios 2.
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