The first International Symposium on Geotechnical Engineering for High-speed Transportation Infrastructure (IS-GeoTrans) will be hosted in Hangzhou between October 26 to 28, 2012, to provide a platform for international exchange of expertise. The theme of IS-GeoTrans 2012 is Safe and comfortable high-speed transportation infrastructure. It intends to provide a venture to discuss the challenges and critical issues in the development and maintenance of high speed transportation infrastructure. The goal is to catalyze the advancement in geotechnology and to prompt scholarly exchange.

A number of dry bridges have been built to substitute for the roadbed on the Qinghai-Tibet Railway, China. The aim of this study was to investigate the exothermic process of cast-in-place (CIP) pile foundation of a dry bridge and its harm to the stability of nearby frozen ground. We present 3D heat conduction functions of a concrete pile and of frozen ground with related boundaries. Our analysis is based on the theory of heat conduction and the exponent law describing the adiabatic temperature rise caused by hydration heat. Results under continuous and initial conditions were combined to establish a finite element model of a CIP pile-frozen ground system for a dry bridge under actual field conditions in cold regions. Numerical results indicated that the process could effectively simulate the exothermic process of CIP pile foundation. Thermal disturbance to frozen ground under a long dry bridge caused by the casting temperature and hydration heat of CIP piles was substantial and long-lasting. The simulated thermal analysis results agreed with field measurements and some significant rules relating to the problem were deduced and conclusions reached.

After describing Japanese slow but steady progress and Chinese very rapid progress of high-speed railways, comparison and analysis of ways of development and those of specific components are discussed. By adding descriptions of European developments which are much different to Japanese, comparisons are made between Japanese and Chinese strong and weak points in order to contribute to the improvement of worldwide rail passengers’ transport including inferior aspect of both countries systems.

This paper, based on a lecture given during tour undertaken in May 2014 of key railway establishments in China, consists of a brief introduction to the history and comparisons of railways in the UK and China, a description of rail speed-up in the last few decades in the UK, and notes of current high speed trains. Similar brief details are given of high speed in Europe. Brief mention is made of comparative railway safety. The development of high speed rail in China is discussed and the UK High Speed development plan is briefly introduced. The paper concluded that high speed train system has tremendous advantages in increasing the efficiency and convenience of transport without adding to carbon generation.

The constriction factor method (CFM) is a new variation of the basic particle swarm optimization (PSO), which has relatively better convergent nature. The effects of the major parameters on CFM were systematically investigated based on some benchmark functions. The constriction factor, velocity constraint, and population size all have significant impact on the performance of CFM for PSO. The constriction factor and velocity constraint have optimal values in practical application, and improper choice of these factors will lead to bad results. Increasing population size can improve the solution quality, although the computing time will be longer. The characteristics of CFM parameters are described and guidelines for determining parameter values are given in this paper.

We present a new algorithm for nesting problems. Many equally spaced points are set on a sheet, and a piece is moved to one of the points and rotated by an angle. Both the point and the rotation angle constitute the packing attitude of the piece. We propose a new algorithm named HAPE (Heuristic Algorithm based on the principle of minimum total Potential Energy) to find the optimal packing attitude at which the piece has the lowest center of gravity. In addition, a new technique for polygon overlap testing is proposed which avoids the time-consuming calculation of no-fit-polygon (NFP). The detailed implementation of HAPE is presented and two computational experiments are described. The first experiment is based on a real industrial problem and the second on 11 published benchmark problems. Using a hill-climbing (HC) search method, the proposed algorithm performs well in comparison with other published solutions.

This paper is focused on the structural behavior of the single shear bolted connections with thin-walled ferritic stainless steel. The purpose of this study is to investigate the ultimate behaviors, such as ultimate strength and fracture mode of the single shear bolted connections of thin-walled ferritic stainless steel (low cost steel) rather than austenitic stainless steel (high cost steel). Bolt arrangement and end distance parallel to the direction of applied load are considered as main variables of the test specimens for bolted connections. Specimens have a constant dimension of edge distance perpendicular to the loading direction, bolt diameter, pitch, and gauge. A monotonic tensile test for specimens has been carried out and some bolted connections with long end distance showed curling (out of plane deformation) occurrence which led to strength reduction. The ultimate behaviors such as fracture mode, ultimate strength are compared with those predicted by current design codes. Further, conditions of curling occurrence and the strength reduction due to curling are investigated and modified strength equations are suggested considering the curling effect.

This paper mainly discusses the problem of ground-borne vibrations due to the planned line 8 of Beijing metro which passes under the National Measurement Laboratory. A lot of vibration sensitive equipments are placed in the laboratory. It is therefore necessary to study the impact of vibrations induced by metro trains on sensitive equipments and important to propound a feasible vibration mitigation measure. Based on the coupled periodic finite element-boundary element (FE-BE) method, a 3D dynamic track-tunnel-soil interaction model for metro line 8 has been used to predict vibrations in the free field induced by trains running at variable speeds between 30 km/h and 80 km/h. Four types of track structures commonly used on the Beijing metro network have been considered: (1) high resilience direct fixation fasteners, (2) Vanguard fasteners, (3) a floating slab track and (4) a floating ladder track. For each of these track types, the vibration isolation efficiency has been compared. The results of the numerical study can be used to predict vibrations in nearby buildings and to decide upon effective vibration countermeasures.

The nesting problem involves arranging pieces on a plate to maximize use of material. A new scheme for 2D irregular-shaped nesting problem is proposed. The new scheme is based on the NFP (No Fit Polygon) algorithm and a new placement principle for pieces. The novel placement principle is to place a piece to the position with lowest gravity center based on NFP. In addition, genetic algorithm (GA) is adopted to find an efficient nesting sequence. The proposed scheme can deal with pieces with arbitrary rotation and containing region with holes, and achieves competitive results in experiment on benchmark datasets.

Geotechnical centrifuge modelling is an advanced physical modelling technique for simulating and studying geotechnical problems. It provides physical data for investigating mechanisms of deformation and failure and for validating analytical and numerical methods. Due to its reliability, time and cost effectiveness, centrifuge modelling has often been the preferred experimental method for addressing complex geotechnical problems. In this ZENG Guo-xi Lecture, the kinematics, fundamental principles and principal applications of geotechnical centrifuge modelling are introduced. The use of the state-of-the-art geotechnical centrifuge at the Hong Kong University of Science and Technology (HKUST), China to investigate four types of complex geotechnical problems is reported. The four geotechnical problems include correction of building tilt, effect of tunnel collapse on an existing tunnel, excavation effect on pile capacity and liquefied flow and non-liquefied slide of loose fill slopes. By reporting major findings and new insights from these four types of centrifuge tests, it is hoped to illustrate the role of state-of-the-art geotechnical centrifuge modelling in advancing the scientific knowledge of geotechnical problems.

Continuum mechanics, just as the name implies, deals with the mechanics problems of all continua, whose physical (or mechanical) properties are assumed to vary continuously in the spaces they occupy. Continuum mechanics may be seen as the symbol of modern mechanics, which differs greatly from current physics, the two often being mixed up by people and even scientists. In this short paper, I will first try to give an illustration on the differences between (modern) mechanics and physics, in my personal view, and then focus on some important current research activities in continuum mechanics, attempting to identify its path to the near future. We can see that continuum mechanics, while having a dominating impact on engineering design in the 20th century, also plays a pivotal role in modern science, and is much closer to physics, chemistry, biology, etc. than ever before.

A high noise level is one of the prominent shortcomings of an axial piston pump which is widely used in industrial and mobile applications. In this paper, a simulation model of an axial piston pump is developed based on a single piston chamber model, for capturing the dynamic characteristics of the discharge flow rate. The compressibility of fluid and main leakages across different friction pairs are considered. The simulation model is validated by a comparison of discharge flow ripple with the measured results using the secondary source method. The main cause of flow ripple is identified by a comparison of the frequency spectrums of actual and kinematic flow ripples. Flow rates with different index angles are analyzed in time and frequency domains. The findings show that an index angle of 20掳 is the most effective in reducing the flow ripple of a tandem axial piston pump, because the frequency contents at odd harmonics can be cancelled out. A sensitivity analysis is conducted at different pressure levels, speeds, and displacement angles, which reveals that with an index angle of 20掳, the sensitivity of flow ripple can be reduced by almost 50% over a wide variety of working conditions.

The temperature distribution in the advanced thermoset composite during the laser curing process was predicted with the use of the two-dimensional thermo-chemical model presented in this paper which also gives the governing equations based on the thermal history of the curing process. The finite-difference method was used to get the temperature distribution. This paper also deals with the effect of some factors (such as the winding velocity, the tape thickness and the laser heat source) on the temperature distribution.

Dielectric elastomers (DEs) respond to applied electric voltage with a surprisingly large deformation, showing a promising capability to generate actuation in mimicking natural muscles. A theoretical foundation of the mechanics of DEs is of crucial importance in designing DE-based structures and devices. In this review, we survey some recent theoretical and numerical efforts in exploring several aspects of electroactive materials, with emphases on the governing equations of electromechanical coupling, constitutive laws, viscoelastic behaviors, electromechanical instability as well as actuation applications. An overview of analytical models is provided based on the representative approach of non-equilibrium thermodynamics, with computational analyses being required in more generalized situations such as irregular shape, complex configuration, and time-dependent deformation. Theoretical efforts have been devoted to enhancing the working limits of DE actuators by avoiding electromechanical instability as well as electric breakdown, and pre-strains are shown to effectively avoid the two failure modes. These studies lay a solid foundation to facilitate the use of DE materials, structures, and devices in a wide range of applications such as biomedical devices, adaptive systems, robotics, energy harvesting, etc.

This article reviews recent developments in fluid power engineering, particularly its market and research in China. The development and new techniques of the pump, valve, and actuator are presented in brief with a discussion of two typical modern fluid power systems, which are the switched inertance hydraulic system and the hydraulic quadruped robot. Challenges and recommendations are given in four aspects including efficiency, compactness and integration, cleanliness, and fluid power education.

Adsorption is one of the widely used processes in the chemical industry environmental application. As compared to mathematical models proposed to describe batch adsorption in terms of isotherm and kinetic behavior, insufficient models are available to describe and predict fixed-bed or column adsorption, though the latter one is the main option in practical application. The present review first provides a brief summary on basic concepts and mathematic models to describe the mass transfer and isotherm behavior of batch adsorption, which dominate the column adsorption behavior in nature. Afterwards, the widely used models developed to predict the breakthrough curve, i.e., the general rate models, linear driving force (LDF) model, wave propagation theory model, constant pattern model, Clark model, Thomas model, Bohart-Adams model, Yoon-Nelson model, Wang model, Wolborska model, and modified dose-response model, are briefly introduced from the mechanism and mathematical viewpoint. Their basic characteristics, including the advantages and inherit shortcomings, are also discussed. This review could help those interested in column adsorption to reasonably choose or develop an accurate and convenient model for their study and practical application.

This study aimed at investigating the characteristics of table and graph that people perceive and the data types which people consider the two displays are most appropriate for. Participants in this survey were 195 teachers and undergraduates from four universities in Beijing. The results showed people?ˉs different attitudes towards the two forms of display.

Recently machine learning-based intrusion detection approaches have been subjected to extensive researches because they can detect both misuse and anomaly. In this paper, rough set classification (RSC), a modern learning algorithm, is used to rank the fea

Randomness plays a major role in the interpretation of many interesting traffic flow phenomena, such as hysteresis, capacity drop and spontaneous breakdown. The analysis of the uncertainty and reliability of traffic systems is directly associated with their random characteristics. Therefore, it is beneficial to understand the distributional properties of traffic variables. This paper focuses on the dependence relation between traffic flow density and traffic speed, which constitute the fundamental diagram (FD). The traditional model of the FD is obtained essentially through curve fitting. We use the copula function as the basic toolkit and provide a novel approach for identifying the distributional patterns associated with the FD. In particular, we construct a rule-of-thumb nonparametric copula function, which in general avoids the mis-specification risk of parametric approaches and is more efficient in practice. By applying our construction to loop detector data on a freeway, we identify the dependence patterns existing in traffic data. We find that similar modes exist among traffic states of low, moderate or high traffic densities. Our findings also suggest that highway traffic speed and traffic flow density as a bivariate distribution is skewed and highly heterogeneous.

There has been intense foundational research in complex technical systems (CTSs) over the last half century. These systems are exemplified by advanced mechatronics systems, embedded control systems, real-time systems, agent-based smart systems, distributed software systems, internet of things systems, and cyber-physical systems. The objective of this paper is to offer an initial cataloguing of the various research domains and to identify the major research issues. The paper has an ontological flavour, because it concentrates on what research has been and is being done, rather than on why and how research is done. The underpinning study has been done in three stages: (i) intuition-driven exploration of a reference set of related academic publications, (ii) evidence-based specification of a categorization of the domains and subdomains of research, and (iii) refinement and validation of the proposed classification based on a control set of related academic publications. The proposed reasoning model identifies three categories of research domains. The ‘intellectualizations’ category includes research domains such as: (i) philosophy, (ii) ontology, and (iii) epistemology of CTSs. The research domains included in the ‘realizations’ category are: (iv) methodology, and (v) creation of CTSs. The domains considered in the ‘influences’ category are: (vi) manifestations, and (vii) axiology of CTSs. Based on the proposed reasoning model a landscape of foundational research in CTSs is proposed for public debate. Our follow-up study focuses on the extension of the proposed classification to other families of complex engineered systems such as sociotechnical systems and social ecosystems.

Fibrillar proteins form structural elements of cells and the extracellular matrix. Pathological lesions of fibrillar microanatomical struc tures, or secondary fibrillar changes in globular proteins are well known. A special group concerns histologically amorphous deposits, amyloid. The major characteristics of amyloid are: apple green birefringence after Congo red staining of histological sections, and non-branching 7-10 nm thick fibrils on electron microscopy revealing a high content of cross beta pleated sheets. About 25 different types of amyloid have been characterised. In animals, AA-amyloid is the most frequent type. Other types of amyloid in animals represent: AIAPP (in cats), AApoAI, AApoAII, localised AL-amyloid, amyloid in odontogenic or mammary tumors and amyloid in the brain. In old dogs Aβ and in sheep APrPsc-amyloid can be encountered. AA-amyloidosis is a systemic disorder with a precursor in blood, acute phase serum amyloid A (SAA). In chronic inflammatory processes AA-amyloid can be deposited. A rapid crystallization of SAA to amyloid fibrils on small beta-sheeted fragments, the ‘amyloid enhancing factor’ (AEF), is known and the AEF has been shown to penetrate the enteric barrier. Amyloid fibrils can aggregate from various precursor proteins in vitro in particular at acidic pH and when proteolytic fragments are formed. Molecular chaperones influence this process. Tissue data point to amyloid fibrillogenesis in lysosomes and near cell surfaces. A comparison can be made of the fibrillogenesis in prion diseases and in enhanced AA-amyloidosis. In the reactive form, acute phase SAA is the supply of the precursor protein, whereas in the prion diseases, cell membrane proteins form a structural source. Aβ-amyloid in brain tissue of aged dogs showing signs of dementia forms a canine counterpart of senile dementia of the Alzheimer type (ccSDAT) in man. Misfolded proteins remain potential food hazards. Developments concerning prevention of amyloidogenesis and therapy of amyloid deposits are shortly commented.

The author designed two algorithms for distributed cooperation among multiple video streams sharing common communication resources. The algorithms take advantage of an optimization framework that characterizes video packets such that joint resource allocation can be implemented not only over the packets of a single stream, but also across packets of different streams. The first algorithm enables collaboration among multiple video senders in an 802.11 CSMA/CA wireless network such that their joint performance is maximized. Via the algorithm, the users cooperatively establish transmission priorities based on the assigned characterizations of their video packets. The second technique allows for low-complexity joint bandwidth adaptation of multiple video streams at intermediate network nodes in the Internet in order to maximize the overall network performance. The author analyzes the advantages of the proposed algorithms over conventional solutions employed in such scenarios. It is shown that depending on system parameters such as available network data rate the proposed techniques can provide substantial gains in end-to-end performance.

Urban growth represents specific response to economic, demographic and environmental conditions. Rapid urbanization and industrializations have resulted in sharp land cover changes. The present investigation was carried out from Shaoxing City to quantify satellite-derived estimates of urban growth using a three-epoch time series Landsat TM data for the years 1984, 1997 and ETM 2000. The methodology used was based on post classification comparison. The use of GIS allowed spatial analysis of the data derived from remotely sensed images. Results showed that the built-up area surrounding Shaoxing City has expanded at an annual average of 7 km2. Analysis of the classified map showed that the physical growth of urban area is upsetting the other land cover classes such as farming, water resources, etc. The study conclusion mainly emphasized the need for sustainable urban capacity.

The construction of the cables is a key step for erecting suspen-dome structures. In practical engineering, it is difficult to ensure that the designed pre-stresses of cables have been exactly introduced into the structures in the site; so it is necessary

This paper presents the construction of a pneumatic active suspension system for a one-wheel car model using fuzzy reasoning and a disturbance observer. The one-wheel car model can be approximately described as a nonlinear two degrees of freedom system subject to excitation from a road profile. The active control is composed of fuzzy and disturbance controls, and functions by actuating a pneumatic actuator. A phase lead-lag compensator is inserted to counter the performance degradation due to the delay of the pneumatic actuator. The experimental result indicates that the proposed active suspension improves much the vibration suppression of the car model.

Nonlinear solution of reinforced concrete structures, particularly complete load-deflection response, requires tracing of the equilibrium path and proper treatment of the limit and bifurcation points. In this regard, ordinary solution techniques lead to instability near the limit points and also have problems in case of snap-through and snap-back. Thus they fail to predict the complete load displacement response. The arc-length method serves the purpose well in principle, received wide acceptance in finite element analysis, and has been used extensively. However modifications to the basic idea are vital to meet the particular needs of the analysis. This paper reviews some of the recent developments of the method in the last two decades, with particular emphasis on nonlinear finite element analysis of reinforced concrete structures.

The chaotic characteristics and maximum predictable time scale of the observation series of hourly water consumption in Hangzhou were investigated using the advanced algorithm presented here is based on the conventional Wolf?ˉs algorithm for the largest Lyapunov exponent. For comparison, the largest Lyapunov exponents of water consumption series with one-hour and 24-hour intervals were calculated respectively. The results indicated that chaotic characteristics obviously exist in the hourly water consumption system; and that observation series with 24-hour interval have longer maximum predictable scale than hourly series. These findings could have significant practical application for better prediction of urban hourly water consumption.

Acoustic signals from diesel engines contain useful information but also include considerable noise components. To extract information for condition monitoring purposes, continuous wavelet transform (CWT) is used for the characterization of engine acoustics. This paper first reviews CWT characteristics represented by short duration transient signals. Wavelet selection and CWT are then implemented and wavelet transform is used to analyze the major sources of the engine front?ˉs exterior radiation sound. The research provides a reliable basis for engineering practice to reduce vehicle sound level. Comparison of the identification results of the measured acoustic signals with the identification results of the measured surface vibration showed good agreement.

This paper describes an in-house developed language tool called VPerl used in developing a 250 MHz 32-bit high-performance low power embedded CPU core. The authors showed that use of this tool can compress the Verilog code by more than a factor of 5, increase the efficiency of the front-end design, reduce the bug rate significantly. This tool can be used to enhance the reusability of an intellectual property model, and facilitate porting design for different platforms.

SAW (Surface Acoustic Wave) filter bank is a single input, single or multi-output device consisting of multi-SAW-filters with input interconnection network or switch circuits, and can be divided into two categories: channelizer (multi-output) and switchable (programmable, single output). The former is mainly used in military channelized receiver for spectrum analysis; the latter has wide application in frequency synthesizer and frequency-hopping radar and communication system receiver as anti-jamming filter, and has been widely used in various military electronic equipments ever since the 1970s. Research abroad was done mainly by Americans, few documents on related work done by Japan and Russia are available. Domestic research started in the 1980s, mainly by No. 26 Research Institute, China Electronics Technology Group Co., Institute of Acoustics, Chinese Academy of Sciences, No. 23 and No. 25 Research Institute, China Spaceflight Tech. Group Co. This paper first briefly introduces Chinese and foreign research on SAW filter banks; then discusses research progress in device design, the input interconnection network or switch circuit and miniaturization; and ends in a brief perspective of developing trends in future.