Editor in chief：朱立光
International standard number：ISSN 1008-1542
Unified domestic issue：CN 13-1225/TS
Domestic postal code：
- Most Read
- Most Cited
- Most Downloaded
2010, 31(3):187-191,200. DOI: 10.7535/hbkd.2010yx03001
Abstract:The problem of the guaranteed cost control for a delay-dependent nonlinear singular system is studied. The purpose is to design a memory state feedback controller, making the closed-loop system asymptotically stable and the corresponding performance index not beyond a certain bound. Based on Lyapunov function method and the linear matrix inequality technique, sufficient conditions for the stability of closed-loop system and explicit expressions of guaranteed cost control are obtained. Finally,the effectiveness of the proposed method is proved by a numerical example.
2010, 31(3):192-194,213. DOI: 10.7535/hbkd.2010yx03002
Abstract:Only with suitable methods and established strategies, the bidder may succeed in bidding for a construction project and make a higher profit. On the basis of literature and , we extend the normal distribution whose parameter is μ and σ, and points out the game situation of price-quoting while the information is not partial to participaters of the bidding. According to the model the paper brings forward optimal quoting prices.
2010, 31(3):195-200. DOI: 10.7535/hbkd.2010yx03003
Abstract:The copolymer of methacrylic acid(MAA) and sodium p-styrene sulfonate(SSS) was synthesized in aqueous solution using potassium persulfate and sodium bisulfite as initiator. The copolymer composition of poly(MAA-co-SSS) was measured by chemical analysis. Reactivity ratios of monomers were evaluated by KT and YBR methods. The distribution function of chain segment of the copolymer was calculated by probabilistic method. The results show that the reactivity ratios of the methacrylic acid and sodium p -styrene sulfornate are 0.06615and 2.412, respectively. With the increasing of MAA ratios in the feed, the number-average length of chain segment of SSS in the compolymer decrease distinctly while the distribution of chain segment of MAA changes little.
2010, 31(3):201-204. DOI: 10.7535/hbkd.2010yx03004
Abstract:According to the dimension and deformation of realistic workpiece, the math model of spinning sealing workpiece was set up, and ANSYS software was applied for 3D numerical simulation of forming process of sealing workpiece. The deformation mechanism was analyzed, and the defects and reasons of sealing workpiece in the numerical simulation deforming were analyzed. It shows that effective stress and strain is bigger with the increase of thickness, the maximum first appears in the circular section, and crack defects comes easily.
2010, 31(3):205-208,213. DOI: 10.7535/hbkd.2010yx03005
Abstract:Based on high-speed photography, experimental study on the stability of rotating transfer and welding process under the control of longitudinal magnetic field is discussed. And the results show that the process of rotating transfer can be controlled by the additional longitudinal magnetic field. Under the shielding gas of 80%Ar+20%CO2, a stable and better controlled rotating transfer is realized with the wire feed speed of 45m/min. Thus the melting efficiency of the welding materials increases obviously.
2010, 31(3):209-213. DOI: 10.7535/hbkd.2010yx03006
Abstract:Based on the minimum resistance law of framework, this paper researched the formation method of the planar changing degree of freedom mechanism (CDFM), put farward three formative methods, summerized four factual patterns, and analyzed the forms in detail with examples,which provide an approach for designing new pattern framewoke.
2010, 31(3):214-218. DOI: 10.7535/hbkd.2010yx03007
Abstract:The basic dynamic characters for the coupled dynamos system are analyzed by phase map, Poincaré section, power spectrum and time series. It involves chaotic attractor, symmetry, equilibrium states and stability. In the case where the knowledge of goal states is not known, an adaptive feedback control is used to stabilize unstable steady states for the coupled dynamos system, and the academic provenance is given. Numerical simulations verify the validity and feasibility of the method.
2010, 31(3):219-221,232. DOI: 10.7535/hbkd.2010yx03008
Abstract:With the development of IEC61850standards and computer technology and communication technology, it is possible to design a new IED of SAS. In this paper, a new protection, measurement and control device is designed for traction transformer. On the basis of logic nodes being assigned to IED, the device design adopts integral structure, with ARM & DSP as hardware platform according to IEC61850standards. Linux is used as software platform. The device has the function of protection, measurement, control and communication, with the characters of high dependability, intelligence and standard.
2010, 31(3):222-226. DOI: 10.7535/hbkd.2010yx03009
Abstract:Aiming at cascading overload aroused by power flow transition and based on direct current flow algorithm, this paper analyzes the triggering factors of cascading failure in power network. Through analysis, this paper points out that the triggering factors of cascading failure mainly comprise initial flow, network structure, branch parameter and initial outage branch of power network when an initial outage event happpens in a system of fixed power source capacity and fixed load. Furthermore, a method of obtaining the limited flow condition under which cascading failure will occur is proposed, and an example with IEEE-14system is presented. The research shows that the limited flow condition is not exclusive, but some rational and credible limited flow condition which will provide guidance for practical operation can be obtained.
2010, 31(3):227-232. DOI: 10.7535/hbkd.2010yx03010
Abstract:An extend RBAC model based on object management is presented.The model applies the role idea to the object and the operation.The object role and the operation role are added on basis of the original model. The relations are added accordingly which are the operation-operation role, the object-object role and the operation-object role. The hierarchical inheriting relation is introduced into the new roles and the static constraint is introduced into the new relations. Formal description of the model is given.
2010, 31(3):233-235,286. DOI: 10.7535/hbkd.2010yx03011
Abstract:Data acquisition is designed to collect in real time the signals of vibration from the weather radar servo motor. In order to realize early warning of weather radar servo motor faults, wavelet packet feature extraction method is used in collection data, and the wavelet packet energy spectrum method is used to make the faults signals quantized and analyzed. The on-site installation verification test proved that the weather radar servo motor faults diagnosis method is a more convenient and accurate method.
2010, 31(3):236-239. DOI: 10.7535/hbkd.2010yx03012
Abstract:This paper presents an improved template matching method of license plate characters recognition. License plate characters recognition process is introduced in detail, which includes the establishment of the template, the character feature extraction based on an elastic mesh, template matching steps and improved methods. By using this method, the computational amount is greatly reduced, while real-time is improved.The experimental result shows that the proposed method has high efficiency, accuracy and good characteristics, and the recognition rate can reach 90%.
2010, 31(3):240-244. DOI: 10.7535/hbkd.2010yx03013
Abstract:The paper describes the image retrieval system of educational resources and basic module structure model firstly, then introduced image feature extraction techniques. In color feature extraction the authors mainly used sub-block histogram method, and the Gabor wavelet transform method was used in texture feature extraction, while the invariant moment method was used in shape feature extraction. Multi-feature was integrated in the first time image retrieval through weight distribution of three characteristics, and then SVM-based relevance feedback technique was used in multiple image retrieval. The experiments indicate that this method can improve the image retrieval precision rate of educational resources effectively.
2010, 31(3):245-251. DOI: 10.7535/hbkd.2010yx03014
Abstract:Synchronization is one of the problems in the auto-test network system. IEEE 1588precision time protocol can realize ns precision, but hardware may restrict it. So software implemenration is more promising. This paper outlines the design of a free IEEE 1588implementation using software only. The experiments prove the method is efficient to implement precise synchronization.
2010, 31(3):252-255. DOI: 10.7535/hbkd.2010yx03015
Abstract:A server cluster system is always adopted to solve the performance bottleneck problem of the network service node, and the load balancing technology is the key factor to decide the whole cluster''s efficiency and scalability. In this paper, the authors present a new kind of load balancing technology which is based on mobile task allocation tables and virtual router clusters.
2010, 31(3):256-259. DOI: 10.7535/hbkd.2010yx03016
Abstract:The cool-film experiments and hot-film experiments are carried out for tooth-type distributors, cone-type distributors and screw-type distributors with different structure parameters, in order to obtain an high-effect liquid distributor to be used in a vertical-tube falling-film evaporator. The experimental results show that the variations of structure parameters of screw-type distributors can make it highly flexible and adaptable to the various requirements, but its head loss is higher. The overall heat transfer coefficient of the screw-type distributor is obviously greater than those of the tooth-type distributor and the cone-type distributor when it is used in a smooth-tube falling-film evaporator. Above all,the synthetical capability of the screw-type distributor is optimal.
2010, 31(3):260-264. DOI: 10.7535/hbkd.2010yx03017
Abstract:Amphiphilic acrylic copolymers were prepared by emulsion copolymerization with potassium persulfate (K2S2O8) as the initiator and MS-1, OP-10as emulsifiers, respectively. The roles of functional monomer (MAA) in amphiphilic acrylic copolymers were studied. The effects of monomer ratio on the distribution of the carboxylic groups (serum, surface, buried) were discussed. It is found that when the amount of MAA is 3%, the free MAA in serum is 6.1% and carboxyl group on particle surface is 50.75%. The structure of polymer was measured by FT-IR. The viscosity average molecular weight of polymer was also studied, and Mη=2.6×105.
2010, 31(3):265-269. DOI: 10.7535/hbkd.2010yx03018
Abstract:In this paper, the relation between the abrasion performances of nylon6fiber and the impact angle is researched. Firstly, a new testing set is designed. When the nylon6fiber is impacted by a high speed air, the wear degree of nylon6fiber can be obtained by the mechanics performance changes before and after the test. The relation between the wear degree and the impact angle has been acquired by experimentation under different impacting angles(15°,30°,45°,60°,75° and 90°).The outward appearance of the fiber before and after the test is obtained and the abrasion performances of nylon6fiber are studied by use of the testing data and the microscope photo.
2010, 31(3):270-273. DOI: 10.7535/hbkd.2010yx03019
Abstract:The damage of microbial corrosion of aircraft fuel tank is serious and even lead to perforation of oil spills and seriously endanger the personal safety. In this paper, micro-organisms for aviation kerosene were isolated and purified to study the types of microbes and microbial fungi and the corrosion mechanism to aircraft fuel tank, then put forward effective control measures. Studies show that microbial contamination of aviation kerosene by the main types of fungi, bacteria and actinomycetes cause pipeline plugging and corrosion perforation.
2010, 31(3):274-277. DOI: 10.7535/hbkd.2010yx03020
Abstract:This paper introduced the A/O-MBBR process on tannery waste water for further processing, examined the effect of wastewater organic matter and ammonia nitrogen treatment effect.The results show that when the filler filling ratio is 60%, the treatment effect of organic matter improves with the HRT extension. When the HRT is up to 12h, COD removal rate reaches 92%; and when the HRT is 12h, with the increase of influent COD concentration, COD removal rate increases, 95% at the 400mg·L-1, later the removal rate decreases when COD concentration continues to increase. The effects of ammonia treatment are that ammonia nitrogen concentration decreases with the extension of HRT; when the HRT is 12h, the effluent ammonia concentration < 1.5mg·L-1；NH3-N removal rate rises with the influent COD getting larger; when COD concentration is 400mg·L-1 it can reach 98%.
2010, 31(3):278-281. DOI: 10.7535/hbkd.2010yx03021
Abstract:The bio-pharmaceutical wastewater contains high SO2-4inhibitory. In the anaerobic environment, sulfate-reducing bacteria produce hydrogen sulfide, and organic matter affects microbial treatment effect. The treatment by coagulation desulphurization and A/O combination technology was adopted. The results show that the technology could achieve a high CODCr removal efficiency of 99.35% and SO2-4removal efficiency of 84.9%. All the quality indexes of the treated water fit grade two requirement for industrial waste water discharge standard.
2010, 31(3):282-286. DOI: 10.7535/hbkd.2010yx03022
Abstract:Based on different goals of controlling shareholders before and after non-tradable share reform, this paper constructs tunneling models separately. Controlling shareholders maximize net assets before non-tradable share reform, but maximize market value of stocks after the reform. We find that the effect of share structure and governance structure on tunneling do not change in manner, but strengthen to some extent.