Abstract:Based on a mechanism logical model, a study was made of the core mechanism of China’s large scale regional development. Results show that the centralized allocation of resources in combination with “the decentralized market oriented development” plays an important role, and the logical relationship model can be constructed by two linear functions and a negative correlation curve function. The evolution is an inevitable transition from a centralized unified system to a decentralized system of small groups’ competition. And the prospects should be a combination of the centralized and the decentralized system in a particular environment instead of a decentralized system towards the absolute one. A further discussion is held on the urban rural development model and the urbanization mechanism, which provides guidelines for future regional development practice.

Abstract:The seismic records of 25 stations at the sites of Class Ⅰ,Ⅱ and Ⅲ in Wenchuan were selected. Their tilt and torsional components were calculated and statistically analyzed according to the relationship between translation and rotational components. The results show that the correlation between translation and rotational components is robust; if the peaks of translation component are the same, the rocking component is larger in softer site; the torsional component is half of the translational component; the attenuation of rotational component is slow.

Abstract:Based on the tests of pre crack push off specimens, the aggregate interlock and shear transfer performance of recycled aggregate concrete (RAC) were investigated. The experimental results reveal that the shear transfer performance across cracks in RAC is similar to that in natural aggregate concrete. When the constraint stiffness is larger, the shear transfer strength of RAC is also higher. With the increase of the RAC strength, the shear transfer strength of the specimen is improved but not obviously. Under the same strength of concrete, the shear transfer strength of specimens decreases slightly with the increase of recycled coarse aggregate replacement ratio, but it decreases marginally. On the basis of Walraven’s investigation and a consideration of the meso structure of RAC as well as the geometry shape of recycled coarse aggregate, an aggregate interlock model for RAC is developed. The shear transfer strength values of each test specimen and the values calculated by the theory agree well with each other.

Abstract:Based on the approximate analytic formulas, an evaluation system for the static behavior of self anchored double tower cable stayed bridge was established. Mechanical evaluation indexes and corresponding parameters were summarized. The sensitivity of various factors was analyzed for the structural mechanics indexes. Then, the effects of mechanic properties of structure system were studied in detail for the mechanical parameters. The research achievement can provide a reference for the conceptual design of self anchored double tower cable stayed bridge.

Abstract:A case study was made of a three pylon cable stayed bridge to investigate the overall vehicle load response of multi span cable stayed bridge under stochastic traffic flow by resorting to the advanced vehicle load research technology, and the differences between the actual and design load responses were also compared. Results show that the current bridge criterion (JTG D60—2004) overvalues the vehicle load response for multi span cable stayed bridge; parameters such as traffic condition and traffic properties of average daily traffic volume and truck ratio affect the response indirectly; different load effects present different sensitiveness to stochastic traffic flow. The results indicate the current load model cannot reflect the actual vehicle load responses in load value as well as loading range, thus, multi parameter and multi level performance based design can be taken into consideration to establish load model reflecting actual traffic condition.

Abstract:The behavior of H section steel members bent about the minor axis was thoroughly investigated by taking the relationship of the plate element slendernesses with the flexural resistance into consideration. A finite element analysis was conducted to investigate the whole loading process behavior of H section steel members composed of different combinations of flange and web slendernesses bent about their minor axis, where the failure mechanism was derived from the stress development curves. It is found that the behavior of such members in pre ultimate stage is mainly affected by the flange width to thickness ratio; while the behavior of such members in the post ultimate stage is significantly affected by the flange web interaction. In addition, the proposed slenderness limit for H section members was put forward, which could attain their full plastic moment resistance when they being bent about the minor axis. Finally, the effective plastic width method for calculating ultimate strength was put forward.

Abstract:The basic theory and the calculation method of “Code for Design of Aluminum Structures” about the bolts joints against shear force were analyzed. 15 tests of shear bolt connections and numerical simulation studies were carried out. The research results show that the value of bearing strength at bolt holes given by “Code for Design of Aluminum Structures” is too conservative. According to the failure phenomena from the experiments and numerical simulation, the deformation failure criterion was proposed. And based on this criterion, numerical studies on the effect of bolt diameter, plate thickness and end distance on the bearing strength at bolt holes were undertaken, and the calculation formula of bolt bearing strength were derived and verified.

Abstract:The force deformation mechanism and failure process under the effects of stick slip dislocation of the normal fault with 45° obliquity was studied by a 1∶50 model experiment. And the strata pressure of the tunnel vault and bottom, axial strain and hoop strain were monitored. Results show that the strata pressure on the vault in the hanging wall and the shear zone increases significantly, followed by the pressure on the vault in the foot wall. The pressure on the tunnel bottom in the hanging wall and the shear zone decreases, while it greatly increases in the foot wall. The tunnel is separated from the wall rock so as to accommodate the shear displacement of the fault. The longitudinal bending moment in the hanging wall and the shear zone is positive and negative in the foot wall zone. By judging the lining failure from the cement prototype under compression, the maximum allowable fault displacement of the prototype is D=0.7 m. Theoretically, the value is overestimated. Tunnel lining fracture length is 1.7 and 2.8 times the width of the tunnel in the shear zone and foot wall respectively.

Abstract:Tunnel heating system using heat pump was introduced for the first time at Zhadun River tunnel in Inner Mongolia Autonomous Region of China to prevent freezing damage in cold region tunnels. Tunnel heating system consists of the heating section, absorbing section, heat pump, collector, and distributor line. This system can be used for heating lining and insulation ditch in tunnel portal. The heat exchange pipes are laid between first lining and second lining in series of longitudinal arrangement. By calculating the decreased ratio of area and moment of inertia of carrying cross section within heat exchange pipes, the results show that the influence of heat exchange pipes on the carrying capacity of tunnel lining is so small that it can be ignored. Tunnel structure includes anchors, waterproof boards and steel arches. The influences of each component on the heat transfer of heat exchange pipes were analyzed by establishing single factor comparison model. The results show that: ① The influence of anchors on the heat transfer of heat exchange pipes is not obvious, only 2.3% at most; ② The disadvantageous influence of waterproof boards on the heat transfer of heat exchange pipes should be considered at the prophase, but it can be ignored after long running; ③ The advantageous influence of steel arches on the heat transfer of heat exchange pipes is obvious at the prophase, but it tends to be not obvious after long running.

Abstract:The fast multipole method (FMM) and generalized minimal residual (GMRES) algorithm are applied to virtual boundary element least square method to solve three dimensional potential problems, so that the amount of the computational elapsed time and the memory volume of the storage problems with the calculation of demand are linearly proportional to the number of degrees of freedom of the problem to be solved. Then the numerical simulation large scale degrees of freedom question might be achieved by the method. Based on the numerical form of virtual boundary element least square method for potential problems, the fundamental solutions of three dimensional potential problems are derived as the numerical scheme to be more suitable for FMM, through the introduction of concepts of diagonalization and exponential expansion moments, in order to further improve the efficiency of the problem with almost the same high precison. The GMRES algorithm is adopted to find the solution of matrix equation. The numerical examples relating to simulation of large scale problems achieved by the method verify the feasibility, efficiency and calculation precision of the method.

Abstract:In this study, 718 traffic analysis zones were classified into 5 groups according to the features of the network. Then, 6 quantitative indexes of different road networks were calculated. It was concluded that Meshedness, proportion of cul de sacs and proportion of four leg intersection were the best measure to distinguish and describe various street patterns. At last, the multinomial logit model was developed based on the above mentioned indices to quantitatively distinguish street patterns, and the accuracy of the model was proved to be 88.4%, which was 3.2% higher than that of the visual inspection. This paper offers an approach to quantitatively distinguish street patterns, which can be used to study the relationship between street patterns and traffic performance.

Abstract:This study, with the city wide station level data limited to be used in prior studies, examines and identifies the transit oriented development(TOD) factors that significantly influence the weekday transit ridership in metropolis of Shanghai by using multivariate regressions. The results show that five variables including the number of daily bus services, average bus headway in station catchment area, walking time to the nearest bus stop, the number of exits of transit stations and parking lot around transit stations, are important in contributing to higher rail transit ridership for Shanghai. In particular, the seemingly contradictory factors of bus service and average headway demonstrate the importance of raising shuttle bus services to the increase of rail transit ridership. Furthermore, the detailed policy implications corresponding with the significant factors are proposed to guide the practice in the urban and transport development.

Abstract:The passenger flow analysis model is composed of three parts. First, based on the stochastic user equilibrium theory, a passenger path choice model was established to determine the passenger principle in path choice and the fundamental basis of traffic distribution in this corridor. Then, a passenger travel cost model was set up with the travel time, in vehicle crowding discomfort, waiting time as three major factors. Finally, an elastic demand model was built up to investigate the interaction between passenger travel intention and rail transit service level. A case study was made of the passenger flow analysis model, which verified the express/slow train operational efficiency in rail transportation corridor.

Abstract:In order to dig the hidden trouble of subway train’s service air braking, the following performance of cylinder volume (CV) actual pressure and CV target pressure is chosen to be the fault feature. According to the change of CV actual pressure of the running train, service air braking process is divided into three typical braking phases: decelerating phase, hold off brake phase and release phase. For each of the three phases with own characteristic a corresponding method is put forward to extract fault feature, including correlation method, mean absolute error method and direct extraction, and there are totally six fault features extracted. At last, the three kinds of typical faults are tested on the brake system reliability test. By means of the criterion of response to the faults, amplitudes of the six fault features in hazard conditions and in normal working condition are compared. And recognition ability of the six fault features are discussed. The effectiveness of the six fault features for excavating the different hidden troubles is established via the comprehensive analysis of the running data and the fault simulation data.

Abstract:The effects of the measured and the designed wheel/rail profiles on Shanghai Metro’s curving behaviors, flange wear, rail wear, corrugation, rolling contact fatigue (RCF) were investigated by modeling a nonlinear vehicle model. The results show that curving behaviors in all four wheel/rail matches satisfy the vehicle dynamics requirements, but the curving behaviors in the designed wheel profile and worn rail profile are less satisfactory. Wheel climbing ratio and value of wheel guiding force in this kind of wheel/rail match are higher. The spinning power of LM/UIC60 on outer rail is very high, leading to side wear of outer rail. The high longitudinal creepages on LM/UIC60 which the outer locates on the negative section of creep force creepage curve and the inner is around saturated point cause stick slip fluctuation easily, then forming corrugation. Besides, by analyzing the RCF, the worn wheel profile damages the outer rail on sharp curve.

Abstract:A nonlinear quasi static analysis on a door seal was carried out to obtain its deformation and stress distribution under different compression ratios. Then the pre stress modal analysis was applied to the deformed seal. To analyze the impacts of pre stress and compression ratio to the transmission loss (TL), the model of which was built by reverberation chamber anechoic chamber method, so that the seal TL could be calculated based on the mode superposition method. The result shows that the pre stress has a great influence on the transmission loss of the low frequency stiffness control area, while the increase of compression ratio will improve the transmission loss of seal effectively within the compression rate of 50%.

Abstract:Air maldistribution has significant impact on the fin and tube heat exchanger performance. In heat pump applications, the influence of four typical air maldistributions on both evaporator and condenser performance was numerically investigated with the simulation software EVAP COND. For comparison, two refrigerants R22 and R410A, three different refrigerant circuitry designs, and four levels of air maldistributions were taken into account. The results show that air maldistribution has more significant impact on the evaporator performance than the condenser. The heavier the air maldistribution, the worse the heat exchanger performance. Heat exchanger performance can be much improved with well designed refrigerant circuitry. The proposed interlaced refrigerant circuitry design has more robust performance subject to variable air maldistributions.

Abstract:Based on characteristics of driver emergency braking behavior in real traffic scenarios, a new threat assessment algorithm was established for control strategy development of automotive collision avoidance system. Real driving scenarios of drivers in the target area were collected by video drive record (VDR). After manual selection and classification according to the scenario typology defined by National Highway Traffic Safety Administration (NHTSA), six typical types of risk scenarios were obtained. Emergency braking behavior of drivers under these typical risk scenarios were analyzed by using video image processing method and then the tTTC(time to collision) values at the starting point of emergency braking as well as the average values of emergency braking decelerations were obtained. These data were then used to establish the threat assessment algorithm based on 1/tiTTC (tiTTC·tTTC=1) and the required deceleration areq. This threat assessment algorithm can take both the fast closing condition and stable following condition into consideration and correspond with driver emergency braking behavior in real traffic scenarios.

Abstract:In order to find out the regular pattern of load variation in the working process of excavator, the field test was resorted to instead of the traditional bench test. Furthermore, the wavelet transform theory was also introduced into the main pump pressure load analysis of excavator in rotary condition and the time frequency processing of pressure data collected in the field test was made. The results show that compared to the traditional random theory analysis, wavelet analysis can not only separate signal trend term, but also further decompose the random terms in accordance with the high and low frequency compared to the traditional random theory analysis. Significantly, wavelet analysis can subtly reveal the structural characteristics of the pressure spectrum of the hydraulic excavator. Therefore, it can provide the fundamental basis for the design and reliability analysis of the hydraulic system of excavators.

Abstract:The paper proposes a new version of local tangent space alignment (LTSA), named multi strategies upgraded local tangent space alignment (MSU LTSA), to solve the problem of computational complexity in dimensionality reduction of hyperspectral imagery (HSI) for classification. First, random projection is introduced into the new method to reduce the number of HSI bands. That decreases the computational complexity of k nearest neighbors (KNNs) construction and local tangent space construction of each pixel. Then, the recursive lanczos bisection algorithm is utilized to construct the fast approximate KNNs graph and it reduces the computational time of regular approach. Finally, when finishing constructing the global alignment matrix, the new method uses the fast approximate singular value decomposition to promote the computational speed of the regular eigenvalue decomposition of global alignment matrix. With two different HSI datasets, four groups of experiments are designed to completely analyze and testify the performance of computation and classification for MSU LTSA. The results show that MSU LTSA speeds up LTSA at least 3 times whereas only degrading about 1% in its overall classification accuracy (OCA).

Abstract:The paper proposes a new version of local tangent space alignment (LTSA), named multi strategies upgraded local tangent space alignment (MSU LTSA), to solve the problem of computational complexity in dimensionality reduction of hyperspectral imagery (HSI) for classification. First, random projection is introduced into the new method to reduce the number of HSI bands. That decreases the computational complexity of k nearest neighbors (KNNs) construction and local tangent space construction of each pixel. Then, the recursive lanczos bisection algorithm is utilized to construct the fast approximate KNNs graph and it reduces the computational time of regular approach. Finally, when finishing constructing the global alignment matrix, the new method uses the fast approximate singular value decomposition to promote the computational speed of the regular eigenvalue decomposition of global alignment matrix. With two different HSI datasets, four groups of experiments are designed to completely analyze and testify the performance of computation and classification for MSU LTSA. The results show that MSU LTSA speeds up LTSA at least 3 times whereas only degrading about 1% in its overall classification accuracy (OCA).

Abstract:A novel method for extracting navigation mark using high resolution remote sensing imagery is proposed in this paper. The one class support vector machine(OCSVM) is used to segment the land and the water to derive the shoreline. Then the small targets within the water regions are found out and regarded as the candidate ones. The statistics of pixel intensity and the geometric feature of the candidate targets are used to remove a portion of false targets. Then the rest of the candidate targets are categorized into several groups according to the relationship coefficient between them and others. The group having most targets is the one that consists of navigation marks. At last, an online learning algorithm is proposed to decrease the miss rate. The spatial distribution of the extracted navigation marks are used to estimate the positions where the missing targets are likely to exist. The intensity distribution of the extracted navigation marks then are used as the prior knowledge to detect the missing target in the estimated positions. The experiments using QuickBird imagery show that the proposed method is effective.

Abstract:A multi counterparties credit default swap（CDS）was investigated. Under the reduced model framework, single factor cox ingersoll ross（CIR）and inversed CIR models were used to characterize positive and negative correlation of the default rates among the counterparties and reference. The counterparty valuation adjustment（CVA）calculation model was obtained, which was expressed by a system of coupled non linear partial differential equations. With this model, CVA was calculated by an iterative numerical algorithm. The results were analyzed correspondingly, which indicated the dependence on the parameters of the CVA, and a comparative study was made with the results of the standard single name CDS.

Abstract:Based on literature review and theoretical analysis, this paper, focusing on the construction projects, describes organizational integration with organizational relationship, organizational ability, organizational structure, and shared value, and it also builds a project performance measurement framework for process performance, quality performance, innovation and learning performance, and stakeholder performance. A questionnaire survey and structural equation modeling are adopted to analyze the path of organizational integration impacting on project performance. The research findings show that: not all key parts of organizational integration have direct effect on different dimensions of project performance; organizational relationship influences all dimensions of project performance through sharing value; the path is more than one for organizational ability, organizational structure, and shared value impacting on different dimensions of project performance. This study enriches the theory of organizational integration and project performance, and also it provides practical guidance for the managers to improve performance in construction industry.

Abstract:Taken in full consideration of logistics service supply chain characteristics and emergent incidents, a set of logistics service supply chain emergency cooperation recovery capability evaluation index system composed by supporting ability, control ability, integrated ability was established. The index system consists of 3 primary indexes, 8 secondary indexes, 31 tertiary indexes. Through the establishment of logistics service supply chain emergency cooperation recovery capability analytic network process(ANP) model, a discussion was held on the inner dependence and external dependencies of various indicators. The Superdecisions software was adopted for evaluation. The results show that, with the method, not only the logistics service supply chain emergency cooperation remedy capability can be evaluated, but also the relationship among various indicators can be analyzed. The fault specification attribution and fault judgment accuracy are ranked first and third respectively, which proves the judgement ability of cooperation recovery to be critical. The model provides an effective theoretical tool for improving the cooperation recovery capability of logistics service supply chain(LSSC).