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20 June 2008, Volume 27 Issue 3 Previous Issue    Next Issue

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Analysis on Static and Lateral Stability of Cable Bridge Construction LIU Qi, ZHOU Shui-xing, CHEN Zhan-rong 2008, 27(3): 335-337.  Abstract ( )   PDF (243KB) ( )   Cable bridge is a type of suspension bridge which depends on the wire rope to suffer the external force.The spatial computation model of a cable bridge was established by the finite element program MIDAS.The static results were in good agreement with that of the test.Reckoning in the geometric stiffness of the rope,the spatial lateral stability of the bridge was analyzed and diverse measures were put forward to improve its lateral stability.After comparing with these methods,the best measure was proposed.The analysis approach and the conclusion are useful for the design and construction of the cable bridge. Related Articles | Metrics

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Analysis on Hyper Static Axial Force in Long Multi-span prestressed Concrete Continuous Box Beam Bridge XIAO Xing-xing, WAN Chong-wen, LI Cheng-hua 2008, 27(3): 338-344.  Abstract ( )   PDF (543KB) ( )   As to long multi-span prestressed concrete continuous girder bridge in cantilever casting construction,when the closure strands is pulled,the pre-applied force in the closure strands compresses beam body to cause the lateral deformation,and one side bearing-friction resistance at closure-mouth will restrain beam body to avoid the lateral deformation,therefore the pre-applied force hyper static axial force is generated.Hyper static axial force,which is a kind of hyper static internal forces just like hyper static moment,is representd generally as tensile force in post tensioned members.From the aspect of bending or cracking resistance capacity,hyper static axial force would make a disadvantageous effect on the post tensioned concrete structures.Based on a 14 cross long multi-span prestressed concrete continuous girder bridge in cantilever casting construction,hyper static axial force resulting from each cross closure strand is calculated.Then the principle,distribution characteristic of the hyper static axial force,as well as the measure of reducing hyper static axial force are discussed.Finally on the base of rorms,pre-applied force hyper static axial force is considered to increase.The formula which is used to design the right section anti-moment and the anti-crack checking for multi-span continuous girder bridge is proposed. Related Articles | Metrics

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Welding Stress Dynamic Simulation Analysis on Extra-thick Plates in Steel Bridge WANG Lin, ZHANG Jiang-ping, WANG Yan-bo, LIU Xiu-wei 2008, 27(3): 345-348,428.  Abstract ( )   PDF (412KB) ( )   The theoretical analysis of welding stress in extra-thick plates has been concerned.Based on ANSYS,using Gauss heat source model heating and element of birth and death,dynamic simulating is used in analysing the butt welding process of 80 mm extra-thick plates.The multi-welding of heating temperature field is simulated,achieving the weld dynamic generation and tracking the changes of the stress field.Simulation results gear with Guanyinyan Yangtze River Bridge welding test results.It offers a useful reference for the design and production of the extra-thick plates. Related Articles | Metrics

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Semi-analytical Solution for Longitudinal Vibration of Elastic Supporting Pile YU Wen-jin 2008, 27(3): 349-352,378.  Abstract ( )   PDF (319KB) ( )   By using a soil modeling of three axes symmetry and considering three dimensions wave effect,the pile's longitudinal vibration characteristic is analyzed on condition of elastic supporting.The frequency domain response of the pile head,complex stiffness and mobility can be obtained as well.According to the convolution theorem and Fourier inversing transforms,a semi-analytical solution of time domain response of velocity admittance is obtained on condition of a stimulating force of a half sine pulsation. Related Articles | Metrics

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Calculating Method of Ultimate Capability of Steel Tube Filled in Concrete Column with Pressure and Moment ZHAO Yu, XIANG Zhong-fu, YANG Hu-gen 2008, 27(3): 353-355.  Abstract ( )   PDF (192KB) ( )   Basic mathematical knowledge is used to deduce the formulas of the column with pressure and moment.According to mechanical theory,ultimate capability of steel tube filled in concrete column with pressure and moment is calculated.Based on the above method,the engineering software Matlab is used to design the program.Some questions are expounded,such as how to divide section,how to modify the parameters,how to judge the limited load,and how to search the value of ultimate capability.Compared with the result of experimentation,the computed results through the program can satisfy the needs of practice. Related Articles | Metrics

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Application and Research of Internal and External Prestressing in the Large Span Continuous Ridge-Frame Bridge LIU Yong-ke, ZHANG Xue-song, XIANG Zhong-fu, SHI Peng-cheng 2008, 27(3): 356-359,391.  Abstract ( )   PDF (404KB) ( )   In view of cracks in the webs and deflections in the middle of span widespreadly existing in the current large span continuous ridge-frame bridge,the Xitan Qijiang bridge has been taken as an example,and a new prestressing system——the internal and external prestressing technique has also been introduced.The right bridge is designed with internal and external prestressing,whereas the other one is designed with internal prestressing.The results of two bridgos have been compared to gain the differences in suffering.From aspects of controling ramp cracks,repressing deflections in the middle of span and economy,the advantages of the internal and external prestressing technique have been discussed. Related Articles | Metrics

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Brief Introduction to the Core Concrete's Empty Influence on the Mechanical Performance of Concrete Filled Steel Tube Components YANG Shi-cong, WANG Fu-min, QU Ping 2008, 27(3): 360-365,486.  Abstract ( )   PDF (677KB) ( )   The research of the core concrete's empty which influences the mechanics performance of concrete filled steel tube components is a hot issue currently.Aiming at the core concrete's filled status of the concrete filled steel tube arch bridge which has been on operation for six years in southwest,through the similitude model trials and theoretic analysis,the core concrete's empty influence on the mechanics performance of concrete filled steel tube components is briefly introduced.It offers referces to the design,construction and examination of this kind of bridge. Related Articles | Metrics

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Analysis on Stability of Concrete Filled Steel Tube Arch Bridge in Construction QIU Lin, SUN Ji-biao 2008, 27(3): 366-369.  Abstract ( )   PDF (294KB) ( )   The linear and nonlinear buckling analysis on stability are introduced.Then according to an concrete filled steel tubular arch bridge,some aspects in construction about stability were discussed.Rational filling method for concrete filled steel tube and some temporary safety facilities in construction can increase the coefficients of stability.The nonlinear influence must be considered in the analysis of stability of concrete filled steel tubular arch bridge in construction. Related Articles | Metrics

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Random Dynamic Response Analysis on Construction Platform Based on Wave Force ZHOU Dan, XIAO Sheng-xie, DU Feng-bin 2008, 27(3): 370-373,412.  Abstract ( )   PDF (415KB) ( )   According to the construction platform of Qingdao Gulf Bridge,finite element programming was used in different frequencies.The calculated dynamic responses was considered to be the excitation from various directions in the action of irregular wave force.The influence of the excitation from various directions on the random dynamic response was analyzed.The results show that the main mode shape of twist is played when excited from 45° direction.Dynamic response experiences two peaks.The calculation results of static and dynamic were compared.The results show that the dynamic influence of the wave force should be considered during designing construction platform. Related Articles | Metrics

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Forecast Analysis of Bridge Life in Southwest China LIN Bin, ZHENG Dan, ZHOU Jian-ting, PENG Li-wei, XU Bin, DAI Yang, HU Zhi-quan 2008, 27(3): 374-378.  Abstract ( )   PDF (355KB) ( )   With bridge in service aging gradually,it is more and more important to evaluate its reliability and forecast its life for better strengthening and rebuilding bridge.According to the difference of information from structure service and management,the residual life of bridge in service in Southwest China is forecasted by regression method,grey theory and neural network model.Experimentd results are also calculated by these methods.Research results mentioned aboae can be used to provide more scientific warrant for strengthening and rebuilding bridge engineering. Related Articles | Metrics

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Progress and Developing Trend of Cable Stress Measuring Methods of Bridge JIANG Jian-shan, TANG De-dong, ZHOU Jian-ting 2008, 27(3): 379-382,466.  Abstract ( )   PDF (485KB) ( )   Four stress measurement methods of large bridge cable are discussed,including tension instrument showing,tension sensing measuring,vibrating frequency sensor and electro-magnetic strain sensor.The basic principles,merits and demerits of these four methods are discussed.In addition,both sensor structure of magnetic-elastic stress sensor and real application in bridges are dissertated.Finally,developing trend of cable stress measurement methods and key technologies are proposed. Related Articles | Metrics

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Research on Discount Rule of External Water Pressure for Highway Tunnel CHEN Lin-jie, JIANG Shu-ping, DING Hao 2008, 27(3): 383-386,404.  Abstract ( )   PDF (353KB) ( )   In order to solve technical problems of external water pressure for highway tunnel,thirty six tests are made under different conditions including different water head height,permeability coefficient,discharge amount and drainage system with own designed apparatus by similar theory.According to test results,discount rule of external water pressure is analysed.Furthermore,some cognitions are also pointed out,which include that the similar relation of water head height is square relation on engineering analogy and composite backfill method is introduced to deal with abundant water cavities around tunnel. Related Articles | Metrics

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Calculating Principle of Tunnel in Debris Flow's Structure WANG Lin-feng, TANG Hong-mei, CHEN Hong-kai 2008, 27(3): 387-391.  Abstract ( )   PDF (334KB) ( )   The most effective way to go through the large-scale debris flow's sedimentary region is the tunnel in debris flow.The key point of the tunnel in debris flow's calculation is how to define the load case.The main differences of structure calculation is the tunnel in debris flow bears the pound of debris flow.When the debris flow breaks out,tunnel in debris flow has two cases.One is deposition,and the other is flush.We can calculate the tunnel in debris flow's internal force by structure mechanics.At the same time,we must consider the tunnel's longitudinal stability,because the tunnel is lay in the debris flow. Related Articles | Metrics

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Research on the Ventilation System of Extra-long Yangjiao Tunnel HU Bai-wan, WEI Qing-hua, LIU Li 2008, 27(3): 392-395,495.  Abstract ( )   PDF (341KB) ( )   Through the study on the ventilation system of Yangjiao extra-long tunnel,which locates in the west development province road passage from Chongqing to Changsha,connecting Wulong with Shuijiang,especially through the research and analysis on some basic parameter affecting ventilation calculation,the calculation standard of extra-long tunnel is given.Besides,design experience of ventilation system of extra-long tunnel is offered. Related Articles | Metrics

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Some Technologic Problems for Center Pillar in Double-Arched Tunnel of Highway GAO Pan-ke, XU Lin-sheng 2008, 27(3): 396-399.  Abstract ( )   PDF (315KB) ( )   During the design and construction process of double-arched tunnel,the role of center pillar is of great importance.Some illustrations of double-arched tunnel constructed recently in our country are listed.Several latest research of key-technology about structural type,appropriate parameter,construction technology and procedure as well as the watertight and drainage system of center pillar are analysed and generalized,which will guide the construction practice. Related Articles | Metrics

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Research on Mechanism of Crack Expanding of Blemish Cement Concrete Pavement WU Guo-xiong, WANG Chen, XIANG Yang-kai, SHE Han-cong 2008, 27(3): 400-404.  Abstract ( )   PDF (374KB) ( )   It is reported that cement concrete pavement occurs inchoate cracks at concrete slab bottom while shrinking,which is a defect.According to this,the basic principle of fracture mechanics is used and the relationship among crack depth at concrete slab bottom,loading,and stress strength factor is got by calculating.And then the expansion condition of pavement's crack is analyzed.Besides,fatigue equation is used to establish the relationship between load repetition and stable fracture tenacity descent,which explains that the basic cause of concrete pavement crack failure is that accumulation total damage resulting from fatigue loads leads to stable fracture tenacity descent. Related Articles | Metrics

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Research on Crack Mechanism of Portland Cement Concrete Pavements ZHAN Hong, DENG Lei-lei 2008, 27(3): 405-407.  Abstract ( )   PDF (258KB) ( )   The crack principle and destruction process are researched by applying the principium of breakage mechanics.The breakage cumulation of portland cement concrete pavement slabs is increased and the rupture temper is decreased under the vehicle load reiterative action of reiterative.With the gradual increase of crack depth,the gene of stress strength caused by the load on the top of the crack will become larger and larger.The pavements slab will rupture when the crack temper makes the portland cement concrete pavements unsteady. Related Articles | Metrics

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Effect and Mechanism of Fiber and Polymer on the Early Shrinkage of Cement Mortar MEI Ying-jun, LI Zhi-yong, LIANG Nai-xing, WANG Pei-ming 2008, 27(3): 408-412.  Abstract ( )   PDF (450KB) ( )   The early (0~6 h) shrinking property of mortar is studied.The shrinkage strain,crack length and width are measured when the shrinking of mortar becomes stable.The following parameters such as nominal crack area,first crack time,shrinkage strain to appraise the effect of fiber (polypropylene and carbon fiber) and polymer on the early shrinking of mortar,the crack mechanism of fiber and polymer on the early shrinking of mortar are also studied.The result indicates that fiber plays reinforcement effect and space effect on mortar,while polymer plays forming film,micro-fiber effect and at the same time it lowers the hydration heat.The effect of fiber together with polymer greatly improves the early shrinking performance of mortar,which is related to the content and elastic module of fiber.With the same content of fiber,carbon fiber shows better effect than polypropylene in restricting early shrinking crack of mortar. Related Articles | Metrics

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Experimental Study on Mechanical Parameters of the Roadbed Filling with Permafrost HUANG Ming-kui, ZHANG Xue-fu, WANG Cheng 2008, 27(3): 413-415,490.  Abstract ( )   PDF (284KB) ( )   The mechanical parameters of rock and soil are the base of the design,construction,theoretical calculation of geotechnical engineering and other mechanical properties researches.It also has great significance for the study of the mechanism of geotechnical engineering.The mechanical parameters of the roadbed filling with permafrost are studied by experiments.It is concluded that the roadbed fill is the discrete,inhomogeneous and mesolow compressible soil.The relations between elastic modulus,shear strength and confining pressure,ground temperature are obtained through cryogenic tri-axial compression test,which provides the bases for other performance studies of the roadbed in cold regions and renders the references for relative performance studies of the similar engineering. Related Articles | Metrics

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Study on Dynamic Mechanism of High-Cutting Slope Deformation CAO Wei-wen, CHEN Hong-kai, YE Si-qiao 2008, 27(3): 416-419.  Abstract ( )   PDF (316KB) ( )   High-cutting slope formed in the excavation of the profect,as to uploading effects,will appear uploading fissure easily.Latent slide will get down and creep ander the action of gravity,which causes some of the firm segment pressed to store elastic strain energy.As the firm segment store shear stress reaching the shear strength of rock mass,slide will have deformation movement.Some correlation theory of the low of conversation and the dynamics are used to obtain the slide's motivating velocity,sliding velocity and sliding distance equation.The example that deformation of high-cutting slope took place in Wulong Chongqing on May 1st,2001 is tested by this method and does well.Evidence is offered to confirm the capability and scope of leading to disastrous of slide,which is in faver of better prevention or reduction against the disaster. Related Articles | Metrics

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Research on the Damage Mechanism due to Freezing and Thawing Force of Control Fissure in Perilous Rock ZHAO Peng, TANG Hong-mei 2008, 27(3): 420-423,445.  Abstract ( )   PDF (443KB) ( )   The formation and expanding of control fissure is the core of mechanism for perilous rock to develop.Based on the theory of damage mechanics,fracture mechanics and elastic mechanics,the formation and expanding of control fissure were researched under the condition of cycle of freezing and thawing.The precondition of control fissure to be damaged and expanded was put forward,and the calculation formulation of frost force on control fissure under freezing condition was established.The applicative method of the calculation formulation has been introduced through an engineering example,and several factors influencing the frost force on control fissure were analyzed.A theoretic foundation for deeper research on the mechanism of perilous rock to develop is established. Related Articles | Metrics

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Decision Making Process of Expressway Routing in Mountainous Area under the Harmony of Projects and the Environment YANG Lin, YAO Ling-kan, QI Ying 2008, 27(3): 424-428.  Abstract ( )   PDF (436KB) ( )   In mountainous area,most of the road engineering march along rivers,where projects conflict directly with the fragile zone of geomorphic environment.Analytical method of structural model is applied to make multilevel hierarchical structural figure on main factors of routing of highway along rivers in mountain areas.The focus of the whole work is to estimate the influence of project on the environment,then to do the best to reduce the disadvantage and to control the disaster from the just beginning of project design.Thus the decision making process of expressway routing in mountainous area with the harmony of projects and the environment is set up.Taking the north segment of narrow mountain pass along Xi-pan road as an example,the working process under direction of the pattern above is introduced. Related Articles | Metrics

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Research on Experiments of the Reasonable Longitudinal Gradient at Alignments of Mountain Highways——Based on Driver's Physiological Reactions TIAN Dong-jun, GAO Wen-bin, PENG Ji-bao 2008, 27(3): 429-432.  Abstract ( )   PDF (335KB) ( )   The structure of the highway alignment has a direct effect on the driving safety.With the longitudinal gradient at the long slope alignment of the mountain highways as the research target,a study of the relationships between the driver's heart-rate,the vehicle speed and the longitudinal gradient of the long slope alignment is made to analyze the reasonable gradient at the long slope,by measuring the driver's heart-rate and the vehicle speed through the auto-recording heart-rate instrument and the motive GPS.On the basis of aboue research,the suggestion that the profile grade at the long slope alignment should not be more than 5% in the mountain highways is proposed. Related Articles | Metrics

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Research on Maintenance Management of Rual Road in Chongqing CHEN Li, HE Zhao-yi, QIAO Dun 2008, 27(3): 433-436.  Abstract ( )   PDF (352KB) ( )   Aiming at Chongqing special rural social economy development level and the actual circumstance of rural road maintenance management,Chongqing rural road of maintenance management has been carried out a systematic research.Through a great deal of investigation work,according to current maintenance management of Chongqing rural road,existent key problems are analyzed systematically;aiming at different mode of maintenance management,project comparison and analysis has been carried out;the fit mode of maintenance management of rural road in Chongqing has been recommended,and a related suggestion has been put forward.These research fruits have certain practical value to insure rural road in Chongqing to keep sustainable development,and more obvious social economic results in the large village region will be produced. Related Articles | Metrics

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A Comparative Study of Road Traffic Safety between Eastern and Western China——Case Study of Jiangsu and Sichuan Province WANG Hong-ming, CHEN Xue-wu 2008, 27(3): 437-441.  Abstract ( )   PDF (461KB) ( )   The economy,culture,and other social aspects have obvious differences from eastern to western China,since the eastern area has taken the leading part in practicing reformation and open policy.Developing situation of road traffic and traffic accidents in recent years has been analyzed in order to research the traffic safety effect produced by economic level in eastern area and western area,taking Jiangsu province and Sichuan province as example.Then the relative magnitude of traffic accidents is compared from aspects of road length,motor vehicle amount,resident population,passenger-kilometers and local GDP.Finally,the result that the total traffic safety situation in Jiangsu is better than that in Sichuan,while the accidental rate per hundred kilometer road,the accidental rate per hundred thousand people and the damage extent of accident in Jiangsu are greater than that in Sichuan is obtained.It is possible that Jiangsu province is concerned with larger passenger-kilometer and frequent travels,and the vehicle's relative-higher-velocity on better quality road. Related Articles | Metrics

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Modeling of the Traffic Incident Dissipation Based on Cell Transmission Model JIYANG Beibei, ZHANG Xiao-ning, SUN Li-jun 2008, 27(3): 442-445.  Abstract ( )   PDF (474KB) ( )   The fundamental principle of the cell transmission model is proposed and the model of the traffic incident dissipation based on CTM is put forward.The creation and dissipation of jam wave at traffic allident area on some highway of Shanghai is analyzed,and simulative calculation on this problem iscamried out based on the CTM.The simulative results show that the jam area near of the incident moves upstream,and it will take a long time when the traffic return to the original situation.The jam will move downstream after the incident is removed.So the effective traffic management is very important to relieve the congest and decrease the traffic delay. Related Articles | Metrics

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Application of Gray Theory in Road Accident Forecast SU Liang, SHAO Dong, TANG Bo-ming, XU Song 2008, 27(3): 446-448.  Abstract ( )   PDF (239KB) ( )   GM(1,1) model is used to forecast the number of serious traffic accidents on Chongqing highway.Based on qualitative analysis and the original data,the appropriate sequence operator is defined.The GM(1,1) model with the appropriate sequence operator is established.The test of forecasting results can make out that the proper sequence operator which improves predicting accuracy.This method is simple and effective,and can be reference. Related Articles | Metrics

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Traffic Impact Evaluation System of City Building Projects Based on Workflow and Matter-element Model WANG Jia-wei, FENG Xiao 2008, 27(3): 449-453.  Abstract ( )   PDF (396KB) ( )   Installation-centered evaluation model is established on the basis of thorough study on the traffic impact analysis of city construction project.According to various traffic impact analysis models of city construction project and the characteristic of flexible evaluation process,the computer software system frame is put forwand based on the workflow and matter-element model,the core technologies that the system frame realizes are comparatively expatiated in detail.Finally,simulation calculation is performed by virtue of a residential area data.The calculation result shows that the model and computer software system frame are effective. Related Articles | Metrics

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Valid Control in Whole Process of Engineering Construction Audit HUANG Xian-gui 2008, 27(3): 454-456.  Abstract ( )   PDF (279KB) ( )   According to the division of the stage of engineering construction,the key contents that the valid control in whole process of engineering construction audits should be strengthened is discussed from the plan stage,the design stage,the implement stage,the evaluation stage etc.each link in construction respectively.Specific audit control measures are given,therefore valid control in whole process of the engineering construction audit is carried out. Related Articles | Metrics

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Fuzzy Judgement on Channelization Pivot Arrangement of Mountainous Area Rivers LI Jun-na, ZENG Xiang-ping, ZHANG Xu-jin, WEN Cen 2008, 27(3): 457-459.  Abstract ( )   PDF (238KB) ( )   The channelization pivot arrangement of mountainous area rivers is a complex subject,involving many factors and most of them are indefinite.Fuzzy judgment is introduced into the optimal selection of the mountainous area channel pivot arrangement,and each scheme is fuzzily judged before the final optimal selection.A new analysis approach is provided. Related Articles | Metrics

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The Spectrum Analysis about Velocity Pulsation of Turbulent Flow in Clear Water LIU Li, YANG Cheng-yu, HE Guang-chun, WEI Qing-hua 2008, 27(3): 460-462.  Abstract ( )   PDF (228KB) ( )   Throagh the data collected current velocity in a period of time,spectrum characteristics of velocity are transformed from current velocity pulse signal in time domain to signal in frequency domain with FFT.The conclusion of turbulent flow energy concentrates in the low frequency is drawn.It finds oat the relations betueen the width of frequency and Fr and that betaeen the width of frequency and Re. Related Articles | Metrics

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Modal Analysis on the Structure of Inland River Overhead-erection Container Terminal HUANG Jian-yong, WANG Duo-yin, SHI Xing-yong 2008, 27(3): 463-466.  Abstract ( )   PDF (446KB) ( )   Because of the complicated structure of inland river overhead-erection terminal,it can't be analyzed by convertional modal analysis but by that of structure special software.By finite element method,modal analysis on the structure of inland river overhead-erection container terminal with the space rigid-frame model has been estab lished and the power property of this structure has beer discussed preliminarily.Accordingly,the calculation result can offer the basis for the study on the structure. Related Articles | Metrics

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Study on Waterway Regulation at Upstream Reach of the Yangtze River BI Fang-quan, LI Jing 2008, 27(3): 467-469.  Abstract ( )   PDF (261KB) ( )   Waterway and shoals characteristics,waterway regulation and construction situations about the Luzhou-Chongqing reach of the Yangtze river are summarized.Regulation principle,hydrogly rule and design water level are proposed.Regu-laion projectdesign and effect forecast are given. Related Articles | Metrics

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Design and Research on the Test Bed of Hybrid Electric Vehicle Based on dSPACE WEI Zuo-gao, LIU Zhen-jun, YE Ming, DENG Tao 2008, 27(3): 470-473.  Abstract ( )   PDF (467KB) ( )   Bed test is very important for the research on hybrid electric vehicle.Comparing with vehicle test,dangerous coefficient of bed test is smaller and components is easier to lay out,so bed test may replace the vehicle test under the condition of testing objects and contents.The dSPACE system and its real-time application to hybrid electric vehicle is introduced,and the testing bed of hybrid electric vehicle is developed.Expatiation is given on the developing ways of control system based on dSPACE. Related Articles | Metrics

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Analysis and Calculation of the Stir Influence to the Radial Airproof Patch of the Triangle Rotor Engine HE Ze-long, LIU Cheng-jun, ZHANG Mi, HE Yu-dong 2008, 27(3): 474-478.  Abstract ( )   PDF (356KB) ( )   The telescopic motion of the radial airproof patch in the airproof groove of the triangle rotor engine is named the stir.It accelerates the abrasion between the cylinder and itself and reduces the airproof performance.The analysis of the influence factors to the stir of the radial airproof patch is expounded and the stir quantity is calculated.It offers references to the design of the triangle rotor engine. Related Articles | Metrics

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Research on Integrated Logistics Networks Modeling and Genetic Algorithm PENG Yong 2008, 27(3): 479-483.  Abstract ( )   PDF (325KB) ( )   How to integrate forward and reverse logistics to decrease the total cost of third party logistics service providers is discussed.A mathematic model is provided without the assumption of straight-line distance.Demand for product and return amount of product are assumed to be distributed stochasticly in this model.Then a genetic algorithm is developed to solve this NP-hard problem and its convergence is discussed.At last a numerical example is available. Related Articles | Metrics

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Weaknesses of a Dynamic Threshold Group Signature Scheme YANG Jian-xi 2008, 27(3): 484-486.  Abstract ( )   PDF (207KB) ( )   All of the existing threshold group signature schemes have weaknesses.The design of an efficient scheme is remained open in cryptography.The weaknesses of a dynamic threshold group scheme are analyzed.The most serious weakness is that part of members can conspire to get system secret parameters and then forge a valid signature. Related Articles | Metrics

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Stability of Second Order Differential Equations with Both Impulse and Delay WEN Tao, SONG Qian-kun 2008, 27(3): 487-490.  Abstract ( )   PDF (250KB) ( )   The problem on stability of second order differential equations with both impulse and delay is investigated.By employing appropriate Lyapunov functional,stability theory and the method controled by impulses,it is proved that unstable second order differential equations can be stabilized by imposition of impulsive controls.The results extend and improve the recently known results.An example is given to show the effectiveness and less conservatism of the proposed criteria. Related Articles | Metrics

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The Integral Solutions of Congruence Equation of Prime Module 19 ZOU Zhao-nan 2008, 27(3): 491-492.  Abstract ( )   PDF (113KB) ( )   The sum of the powers of some continue integers is considered,where the powers have positive even exponent.Some properties of the sum module 19 have been presented.Especially,the solutions of the corresponding equation have been researched.If the equation has solutions,all the solutions are given here. Related Articles | Metrics

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The Holomorph of Zp×Zp and the Number of Isomorphic Groups of Order p2q DUAN Cheng-jun, XIA Xing-wu 2008, 27(3): 493-495.  Abstract ( )   PDF (207KB) ( )   The groups,in which the number of prime divisors in the order is small and the degrees of each prime divisor in the order are small too,have important significance in the research of groups.Many results of structure of groups,such as the structure of solvable groups,are narrated by using these groups.Using the method of linear group and the ideals of linear representation of group,a sufficient condition that two relative holomorphs of Zp×Zp are isomorphic is given.By using it,another proof of the number of groups of order p2q is given,which is non-isomorphic groups pair-wisely. Related Articles | Metrics

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New Characteristics and Application of Prequasi-invex Functions PENG Zai-yun, LIU Ya-wei 2008, 27(3): 496-498.  Abstract ( )   PDF (209KB) ( )   A new class of important generalized convex functions-prequasi-invex function is further discussed.To improve research on the generalized convex function,some new characteristics of the prequasi-invex function are figured out by means of the cographical set of function (E(f)={(x,α):x∈K,α∈R,f(x)≤α}) and η-invex set,and its two applications in the mathematical programming problem are proposed.So the study of this type generalized convex function becomes further now. Related Articles | Metrics