Applied Mechanics and Materials Vol. 392

Abstract: The total throughput of the communication system can be maximized by allocating the common radio resource to the user or the user group having the best channel quality at a given time and the multiuser diversity gain can be obtained when multiple users share the same channel at one time. The object to select the users is to select the users with the maximum sum capacity. As for a scheduling algorithm, exhaustive algorithm can get the largest capability of the system by multi-user scheduling. However, this algorithm is quite complex hence the cost of operation to a base station has substantial increased. We compare the multiuser performance of two fast user selection algorithms with low complexity in MIMO-MRC systems with co-channel interferences. From the simulation results, these two algorithms not only decrease the computational complexity of the scheduling algorithm but also retain large capability of the MIMO system.

Abstract: The media access control (MAC) protocol based on fixed slot allocation has low throughput and high delay in high load wireless mesh network. In order to improve the performance of wireless mesh network, we propose a scalable adaptive time division multiple access (TDMA) slot allocation algorithm based on the existing fixed TDMA. The algorithm uses the network structure of clustering and builds a more optimized frame structure, cluster head dynamically allocates time slot according to the packet number of the cluster member sent and the priority level, at the same time taking into account the situation of nodes joining and leaving to improve the scalability of the network The simulation results on OPNET network simulation platform show that the algorithm is superior to fixed TDMA algorithm in both throughput and delay.

Abstract: Brick-concrete structures and common buildings are destroyed in strong earthquakes. Based on physical mechanics, a pattern contrast illustrates three special designs of building structure---removal of basal markets and underground garages, use of corrugated beams, adoption of trapezoid bars---that may effectively avoid damages and casualties.

Abstract: This paper discusses on the extension of integrated protection, and aim at the contradiction of protection and development of the history protection area. Put forward the dynamic development protection concept as a solution. Take the conservation planning practice of Jinggang Mountain revolutionary site area as an example, analyze the dialectical relationship between protection and development, discusses the possible of dynamic integrate development view in the protection planning.

Abstract: The deformation mechanism of surrounding rock during excavation is difficult to stability evaluation for large-span shallow-buried double-arch tunnel. Take Fenghuang mountain tunnel in Suzhou city as an example, the main work and funding are as follow: The measured data in the middle of the tunnel, including settlement on the top of the tunnel and deformation between two lateral walls, were used to calculate mechanical parameters by back analysis method. The obtained parameters were used to calculate the deformation and stress of the main tunnel excavation in the different steps. The rules includes time-space effect during main tunnel excavation, force mechanism of the middle wall and settlement on the ground surface for the surrounding rock in the main tunnel. Finally, the calculated settlement and deformation were compared to the monitoring results. The safety coefficient of surrounding rock for double-arch tunnel was obtained by strength reduction theory.

Abstract: The airport cement concrete pavement seam is very important to the bearing capacity and Flatness. Considering the importance of seams, a detailed three-dimensional finite element model was used to investigate the state of seams. According the calculation method of load transfer coefficient, the coefficient was obtained. Comparing the different coefficient, the best position of dowel steels, the best diameter of dowel steels, the best buried depth of dowel steels and the best joint width of dowel steels all can be gained best joint width of dowel steels all can be gained.

Abstract: In order to meet wave accuracy and response time requirements, its necessary to have the installing truss finite element analyzed, which can bring a knowledge of the stress and deformation of the installing truss at the same time. The force acted on the installing truss should be learnt before the finite element analysis of it, including the gravity of the wave-makers, the gravity of the installing truss, the resistance of water (transmit from the wave-plate),the torque caused by the resistance and the gravity of the installing truss is one of the important factors that affect the deformation. With the method of statics analysis and harmonic analysis, this paper have a further study on the effect of gravity of installing truss on its deformation.

Abstract: The study of the mechanical properties of pile-soil interface is an important aspect to research the vertical bearing behavior of piles. Currently special direct shear tests and special simple shear tests are usually used to study the mechanical properties of soil-structure interface. But those tests have shortcomings of difficulty in simulating the force properties of complex interface. In this paper, the mechanical properties of different interface between soil and concrete surface were studied through the large-scale direct shear tests.

Abstract: Digital technology has played a crucial role in architectural development since being introduced in. Different application of digital design software has taken the place of traditional drawing. The innovated architecture design process has promoted a trend of space complexity. Advanced digital technology also produced a new design method; the computer can generate a unique building plan through the special program directly rather than the imagination of the human brain. Besides, digital technology has a wide range of applications in exploring the future architecture development, as well as virtual reality in the scheme deliberation and demonstration. The digital architecture has broken through the two-dimensional architectural design pattern and the aesthetic consciousness of the industrial era, and pushes the building industry development greatly.

Abstract: The model test is an effective means to verify the mechanical performance of the bridge structure and to ensure the structural safety. The accuracy of design and manufacture is the key of model test.For a arch ridge with curved beam and skewed arch, the model test based on the similarity theory is analysized in detail including selecting materials, designing the size of section and calculating the geometrical parameters and so on, and the simulation reults between model and prototype are evaluated.Meanwhile some key technologies and valuable matters for design of aerodynamic model are presented,which provides an important reference value for model design of bridge structures.