Title:Comment on Lee J-s et al.'s identity-based designated verifer proxy signature scheme and its improvement
Author affiliation:(1) College of Science, Huaihai Institue of Technology, Lianyungang 222005, China; (2) Sch of Math. Sci., Yangzhou Univ., Yangzhou 225002, China
Abbreviated source title:Adv. Mater. Res.
Conference name:International Conference on Smart Materials and Intelligent Systems 2010, SMIS 2010
Sponsor:Shanghai Jiao Tong University; Nanyang Normal University; Hebei Polytechnic University; Henan Institute of Science and Technology; Chongqing University of Arts and Sciences; Hunan Institute of Engineering
Publisher:Trans Tech Publications, P.O. Box 1254, Clausthal-Zellerfeld, D-38670, Germany
Abstract:In a designated verifier proxy signature scheme, one can delegate his or her signing capability to another user in such a way that the latter can sign messages on behalf of the former, but the validity of the resulting signatures can only be verified by the designated verifier. Recently, Lee J-s et al. proposed a new ID-Based designated verifier proxy signature scheme. They didn't analysis the security of their scheme. We found out that anyone can generate a valid signature on any message m and mw he choose. To overcome this flaw in Lee J-s et al.'s scheme, we formalized the notion of designated verifier proxy signature scheme, provide a new ID-Based designated verifier proxy signature scheme. We also analyzed the proposed scheme. © (2011) Trans Tech Publications.
Controlled terms:Authentication - Cryptography - Intelligent materials - Intelligent systems - Network security
Uncontrolled terms:Designated verifiers - Designated-verifier proxy signatures - ID-based - Identity-based - Proxy signature scheme - Proxy signatures - Sign messages - Strong designated verifer signatures
Classification code:415 Metals, Plastics, Wood and Other Structural Materials - 723 Computer Software, Data Handling and Applications
Compilation and indexing terms, Copyright 2011 Elsevier Inc.
Accession number:20111413898041
Title:Comparison of bulb tubular pump unit's support forms
Authors:Qiu, Baoyun (1); Pei, Bei (1); Shen, Jian (1); Feng, Xusong (2); Feng, Xiaoli (1)
Author affiliation:(1) School of Energy and Power Engineering, Yangzhou University, Yangzhou, Jiangsu 225127, China; (2) Jiangsu Water Source Co. Ltd. of S-to-N Water Transfer Project, Nanjing, Jiangsu 210029, China
Corresponding author:Qiu, B.(yzdxqby@sohu.com)
Source title:Paiguan Jixie Gongcheng Xuebao/Journal of Drainage and Irrigation Machinery Engineering
Abbreviated source title:Paiguan Jixie Xuebao.
Volume:29
Issue:1
Issue date:January 2011
Publication year:2011
Pages:61-66
Language:Chinese
ISSN:16748530
CODEN:PAJIE2
Document type:Journal article (JA)
Publisher:Editorial Department of Drainage and, 30 Mengxiyuan Lane, Zhenjiang, 212003, China
Abstract:In order to optimize supporting structures of bulb tubular pump units and improve the properties, the supports of bulb tubular pump units were divided into 3 hierarchies, i.e. the bearing block support, the bulb support and the pump body support. The support forms of 3 typical bulb tubular pump units were investigated. The shaft deformations and fatigue strength safety factors were calculated through force analysis. Several typical support forms were compared in pump unit reliability, installation, maintainability and overall structure, and the pump system hydraulic performances. The design principles and methods of bulb tubular pump unit supports were put forward in bearing number and their arrangement and installation, the bulb supports and the pump body supports. The results show that supporting forms of bulb tubular pump units affect reliability, stability, installation and maintainability of the pump units and the pump system hydraulic performances. The flexivities of motor rotor and pump impeller reach 0.19~0.39 mm and 0.22~0.62 mm, respectively. The oil film thicknesses of journal bearings and rolling bearings are 0.41~0.53 mm and 0.12~0.17 mm, respectively. When determining the installation height of the bearing saddle, the flexivities of the rotor and the impeller and oil film thicknesses of the bearings should be considered so that the motor's air gap and the clearance between pump blade and shell are evenly distributed. The reliability and hydraulic performances of bulb tubular pump units could be improved by reasonably arranging guide bearings, adopting radiating plate support of the bulb, combining the maintenance channel and the main support which is under the bulb, and using the metal pipe pump structure. The achievements could provide references to optimum design of bulb tubular pump units.
Number of references:10
Main heading:Pumps
Controlled terms:Bearings (structural) - Design - Hydraulics - Impellers - Journal bearings - Lubricating oils - Maintainability - Plate metal - Quality assurance - Reliability - Safety factor
Uncontrolled terms:Air-gaps - Assembly quality - Bearing block - Bulb tubular pump units - Design Principles - Fatigue strength - Force analysis - Guide bearing - Hydraulic performance - Metal pipes - Motor rotors - Oil films - Optimum designs - Pump impeller - Pump structure - Pump system - Rolling bearings - Shaft deformation - Structure design - Supporting structure
Classification code:913.3 Quality Assurance and Control - 632.1 Hydraulics - 618.2 Pumps - 913.5 Maintenance - 607.1 Lubricants - 535.1.2 Rolling Mill Practice - 408 Structural Design - 601.2 Machine Components
DOI:10.3969/j.issn.1674-8530.2011.01.013
Database:Compendex
Compilation and indexing terms, Copyright 2011 Elsevier Inc.
Accession number:20111213783947
Title:Longitudinal vibration of a metal core piezoelectric fiber
Authors:Bian, Yi-Xiang (1); Qiu, Jin-Hao (2); Wang, Xin-Wei (2)
Author affiliation:(1) College of Mechanical Engineering, Yangzhou University, Yangzhou 225127, China; (2) Key Lab of Smart Materials and Structures, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
Corresponding author:Bian, Y.-X.
Source title:Zhendong yu Chongji/Journal of Vibration and Shock
Abbreviated source title:J Vib Shock
Volume:30
Issue:1
Issue date:January 2011
Publication year:2011
Pages:111-115
Language:Chinese
ISSN:10003835
Document type:Journal article (JA)
Publisher:Chinese Vibration Engineering Society, 121 Nanjiang Lu, Shanghai, 200011, China
Abstract:A metal core piezoelectric fiber (MPF) is one of the new type piezoelectric devices for sensors and actuators. When an external harmonically varying voltage is applied on electrodes of a cantilevered MPF, it will cause longitudinal vibration. A force appears due to the strain caused by the electric field in the piezoelectric elements. Using the vibration theory of a cantilevered bar, the longitudinal vibration equations of the MPF were derived. The electric displacement was deduced by using the constitutive equations of the piezoelectric element. And the electric charges on the electrodes were given by integrating electric displacement. The total current flowing through the electrode surface and the admittance of the MPF was derived from the electric charges. Using the resonance frequency, the elastic coefficient at a constant electric field S11E was given from the admittance. And using the antiresonance frequency, the electromechanical coupling factor R31 was obtained. The dielectric permittivity under a constant stress Ε 33T was extracted with the lower capacitance. Using above parameters, the piezoelectric coefficients d31 was calculated. One experiment was performed. The theoretical simulations and experimental results showed that this method is effective to measure the properties of MPF.
Number of references:15
Main heading:Piezoelectric actuators
Controlled terms:Constitutive equations - Electric charge - Electric fields - Electrodes - Electromechanical coupling - Electromechanical devices - Fibers - Metal testing - Metals - Piezoelectricity - Resonance - Testing
Uncontrolled terms:Antiresonance frequencies - Cantilevered bar - Constant stress - Dielectric permittivities - Dynamic testing - Elastic coefficient - Electric displacement - Electro mechanical coupling factors - Electrode surfaces - Longitudinal vibrations - Metal core - Metal core piezoelectric fibers - Piezoelectric coefficient - Piezoelectric elements - Piezoelectric fiber - Resonance frequencies - Sensors and actuators - Theoretical simulation - Total current - Vibration - Vibration theory
Classification code:921 Mathematics - 817 Plastics and Other Polymers: Products and Applications - 812 Ceramics, Refractories and Glass - 732 Control Devices - 715 Electronic Equipment, General Purpose and Industrial - 708 Electric and Magnetic Materials - 704.1 Electric Components - 701.1 Electricity: Basic Concepts and Phenomena - 701 Electricity and Magnetism - 601 Mechanical Design - 531 Metallurgy and Metallography - 423.2 Non Mechanical Properties of Building Materials: Test Methods - 408 Structural Design
Database:Compendex
Compilation and indexing terms, Copyright 2011 Elsevier Inc.
Accession number:20111413898043
Title:Numerical simulation of optimal bulb of tubular pump
Authors:Zhou, Jiren (1); Cheng, Li (2); Liu, Chao (2); Tang, Fangping (2)
Author affiliation:(1) College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing, Jiangsu 210098, China; (2) College of Hydraulic Science and Engineering, Yangzhou University, Yangzhou, Jiangsu 225009, China
Corresponding author:Zhou, J.(zhoujr@yzu.edu.cn)
Source title:Paiguan Jixie Gongcheng Xuebao/Journal of Drainage and Irrigation Machinery Engineering
Abbreviated source title:Paiguan Jixie Xuebao.
Volume:29
Issue:1
Issue date:January 2011
Publication year:2011
Pages:72-76
Language:Chinese
ISSN:16748530
CODEN:PAJIE2
Document type:Journal article (JA)
Publisher:Editorial Department of Drainage and, 30 Mengxiyuan Lane, Zhenjiang, 212003, China
Abstract:The flow patterns and hydraulic performances of two different bulbs of pump system, i.e. normal type and slin type, were studied. Based on the RNG k-Ε model, the SIMPLEC algorithm was applied to the solution of the discretization governing equation. Using multiple reference frames, the flow details of whole pumping systems whose length was of 10.72D, where D was of the impeller diameter, were obtained. The influences of the flow of pump system on difference bulbs were analyzed. The unsuitable design of bulbs caused flow separation and vortex. The calculation results illustrate that the static pressure contours of two pumping systems which were operated at design flowrate, large flowrate and small flowrate, were similar, and therefore the shape of bulb does not impact on the operation status of impellers. The results showed that the flowrate of minimum loss for slin taper bulb is of 112 percent of design flowrate, while that for normal bulb is of 106 percent of design flowrate. It is not quadratic function between flowrate and hydraulic loss, and the loss is somewhat related with the operating region. 3D numerical computation and model test showed that the performance of slin taper bulb was better than that of normal one, and consequently this type of pump system can be applied in the East Route Project of South-to-North Water Transfers.
Number of references:10
Main heading:Mathematical models
Controlled terms:Blowers - Design - Hydraulics - Impellers - Optimization - Pumping plants - Pumps - Three dimensional
Uncontrolled terms:Bulb - Discretizations - Governing equations - Hydraulic loss - Hydraulic performance - Model tests - Multiple-reference frames - Numerical computations - Numerical simulation - Operating regions - Operation status - Pump system - Pumping systems - Quadratic function - SIMPLEC algorithm - Small flow-rate - South-to-North Water Transfer - Static pressure - Tubular pump
Classification code:921.5 Optimization Techniques - 921 Mathematics - 902.1 Engineering Graphics - 632.1 Hydraulics - 618.3 Blowers and Fans - 618.2 Pumps - 601.2 Machine Components - 446 Waterworks - 408 Structural Design
DOI:10.3969/j.issn.1674-8530.2011.01.015
Database:Compendex
Compilation and indexing terms, Copyright 2011 Elsevier Inc.
Accession number:20113214220652
Title:Nano express open accepreparation of stable magnetic nanofluids containing fe3o4@ppy nanoparticles by a novel one-pot route
Authors:Baobao, Zhao (1); Nan, Zhaodong (1)
Author affiliation:(1) College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, 225002, China
Corresponding author:Baobao, Z.(zdnan@yzu.edu.cn)
Source title:Nanoscale Research Letters
Abbreviated source title:Nanoscale Res. Lett.
Volume:6
Issue:1
Issue date:January 2011
Publication year:2011
Pages:1-8
Language:English
ISSN:19317573
E-ISSN:1556276X
Document type:Journal article (JA)
Publisher:Springer New York, 233 Springer Street, New York, NY 10013-1578, United States
Abstract:Stable magnetic nanofluids containing Fe3O4@Polypyrrole (PPy) nanoparticles (NPs) were prepared by using a facile and novel method, in which one-pot route was used. FeCl3·6H2O was applied as the iron source, and the oxidizing agent to produce PPy. Trisodium citrate (Na3cit) was used as the reducing reagent to form Fe3O4 NPs. The as- prepared nanofluid can keep long-term stability. The Fe3O4@PPy NPs can still keep dispersing well after the nanofluid has been standing for 1 month and no sedimentation is found. The polymerization reaction of the pyrrole monomers took place with Fe3+ ions as the initiator, in which these Fe3+ ions remained in the solution adsorbed on the surface of the Fe3O4 NPs. Thus, the core-shell NPs of Fe3O4@PPy were obtained. The particle size of the as-prepared Fe3O4@PPy can be easily controlled from 7 to 30 nm by the polymerization reaction of the pyrrole monomers. The steric stabilization and weight of the NPs affect the stability of the nanofluids. The as- prepared Fe3O4@PPy NPs exhibit superparamagnetic behavior. © 2011 Zhao and Nan.