Direct computing methods for turn flows in traffic assignment

Two methods based on a slight modification of the regular traffic assignmentalgorithms are proposed to directly compute turn flows instead of estimating them from link flows orobtaining them by expanding the networks. The first one is designed on the path-turn incidencerelationship, and it is similar to the computational procedure of link flows. It applies to thetraffic assignment algorithms that can provide detailed path structures. The second utilizes thelink-turn incidence relationship and the conservation of flow on links, a law deriving from thisrelationship. It is actually an improved version of Dial's logit assignment algorithm. The proposedapproaches can avoid the shortcomings both of the estimation methods, e. g. Furness's model andFrator's model, and of the network-expanding method in precision, stability and computation scale.Finally, they are validated by numerical examples.

Microstructural evolution and mechanical properties of Ti-5Al-5Mo-5V-3Cr alloy by heat treatment with continuous temperature gradient

A new high throughput heat-treatment method with a continuous temperature gradient between 600 and 700 ？C was utilized on the Ti-5553 alloy（Ti-5 Al-5 Mo-5 V-3 Cr, mass fraction, %）. The temperature gradient was induced by the variation of the axial section of sample, which was heated by the direct current. The variation of continuous cooling rates on the treated sample was realized by using the end quenching method. The microstructural evolution and mechanical properties under different heat treatment conditions were evaluated. The results show that the pseudo-spinodal decomposition of the alloy occurs at（617±1） ？C, and the size of the precipitated α phase is around 300 nm. Moreover, the highest microhardness is obtained after the heat treatment at the pseudo-spinodal decomposition temperature for 4 h. These indicate that the high throughput method is efficient and fast to determine the phase transformation temperature and corresponding microstructural evolution of alloys.

Robust Blind Separation for MIMO Systems against Channel Mismatch Using Second-Order Cone Programming

To improve the deteriorated capacity gain and source recovery performance due to channel mismatch problem,this paper reports a research about blind separation method against channel mismatch in multiple-input multiple-output(MIMO) systems.The channel mismatch problem can be described as a channel with bounded fluctuant errors due to channel distortion or channel estimation errors.The problem of blind signal separation/extraction with channel mismatch is formulated as a cost function of blind source separation(BSS) subject to the second-order cone constraint,which can be called as second-order cone programing optimization problem.Then the resulting cost function is solved by approximate negentropy maximization using quasi-Newton iterative methods for blind separation/extraction source signals.Theoretical analysis demonstrates that the proposed algorithm has low computational complexity and improved performance advantages.Simulation results verify that the capacity gain and bit error rate(BER) performance of the proposed blind separation method is superior to those of the existing methods in MIMO systems with channel mismatch problem.

ANALYSIS AND MEASUREMENT OF LARGE DYNAMIC RANGE RF SWITCH INTER-MODULATION

Radio Frequency (RF) switch circuit is the basic part of microwave devices and systems. The non-linearity distortion figure is necessary in the field of large dynamic range of signal. This letter analyzes the basic switch circuit and its inter-modulation, and studies in detail the measurement methods and systems of RF switch intercept point. It has provided cascaded simulation testing methods, which can accurately measure the PF switch, of which the second or third order intercept point value is above 75dB and 60dB, respectively. As the testing results are consistent with the theoretical analyses, it proves that the validity of the method satisfies the requirements of large scaled linearity measurement in engineering.

A Secure Session Key Distribution Scheme for Group Communications

In a secure group communication system, messages must be encrypted before being transmitted to group members to prevent unauthorized access. In many secure group communication schemes, whenever a member leaves or joins the group, group center (GC) immediately changes the common encryption key and sends the new key to all valid members for forward and backward secrecy. If valid members are not on-line, they will miss the re-keying messages and will not be able to decrypt any ciphertext. Therefore, group members must be able to store the state of the system. In some applications, like global positioning systems (GPS) or pay-per-view systems, it is not reasonable to ask group members to stay on-line all the time and save the changes to the system. A hierarchical binary tree-based key management scheme are proposed for a secure group communication. This scheme reduces the key storage requirement of GC to a constant size and the group members are not required to be on-line constantly (stateless).

An Ocular Artifacts Removal Method Based on Canonical Correlation Analysis and Two-Channel EEG Recordings

In order to more effectively apply an artifact removal melhod in an online brain-computer interface （BCI） system, a new method based on canonical correlation analysis （CCA） and two-channel eleetroeneephalography （EEG） recordings to quickly remove ocular artifacts （OA） is proposed in this paper. Considering both the formation of EEG signals contaminated by OA and the spread of OA, vertical electrooculo~＇aphy （VEOG） was appropriately introduced in CCA, and the blind source separation （BSS~ method based on CCA was used in a new way during the OA removal process. Both experimental and comparison with ICA and SOBI results show that the new method with simple calculation and fast processing speed can effectively separate and remove OA using only two-channel EEG recordings, with retaining useful EEG signals. Hence, this method used in an online BCI system will be more effective.

The Anomaly Detection in SMTP Traffic Based on Leaky Integrate-and-Fire Model

This paper investigated an effective and robust mechanism for detecting simple mail transfer protocol (SMTP) traffic anomaly. The detection method cumulates the deviation of current delivering status from history behavior based on a weighted sum method called the leaky integrate-and-fire model to detect anomaly. The simplicity of the detection method is that the method need not store history profile and low computation overhead, which makes the detection method itself immunes to attacks. The performance is investigated in terms of detection probability, the false alarm ratio, and the detection delay. The results show that leaky integrate-and-fire method is quite effective at detecting constant intensity attacks and increasing intensity attacks. Compared with the non-parametric cumulative sum method, the evaluation results show that the proposed detection method has shorter detection latency and higher detection probability.

Stability of mine ventilation system based on multiple regression analysis

In order to overcome the disadvantages of diagonal connection structures that are complex and for which it is difficult to derive the discriminant of the airflow directions of airways, we have applied a multiple regression method to analyze the effect, of changing the rules of mine airflows, on the stability of a mine ventilation system. The amount of air （ Qj ） is determined for the major airway and an optimum regression equation was derived for Qi as a function of the independent variable （ Ri ）, i.e., the venti- lation resistance between different airways. Therefore, corresponding countermeasures are proposed according to the changes in airflows. The calculated results agree very well with our practical situation, indicating that multiple regression analysis is simple, quick and practical and is therefore an effective method to analyze the stability of mine ventilation systems.

A SVM Based Text Steganalysis Algorithm for Spacing Coding

Group distance coding is suitable for secret communication covered by printed documents. However there is no effective method against it. The study found that the hiding method will make group distances of text lines coverage on specified values, and make variances of group distances among N-Window text lines become small. Inspired by the discovery, the research brings out a Support Vector Machine （SVM） based steganalysis algorithm. To avoid the disturbance of large difference among words length from same line, the research only reserves samples whose occurrence-frequencies are ± 10dB of the maximum frequency. The results show that the correct rate of the SVM classifier is higher than 90%.

Heat transfer of copper/water nanofluid flow through converging-diverging channel

The main objective of this work is to investigate analytically the steady nanofluid flow and heat transfer characteristics between nonparallel plane walls. Using appropriate transformations for the velocity and temperature, the basic nonlinear partial differential equations are reduced to the ordinary differential equations. Then, these equations have been solved analytically and numerically for some values of the governing parameters, Reynolds number, Re, channel half angle, α, Prandtl number, Pr, and Eckert number, Ec, using Adomian decomposition method and the Runge-Kutta method with mathematic package. Analytical and numerical results are searched for the skin friction coefficient, Nusselt number and the velocity and temperature profiles. It is found on one hand that the Nusselt number increases as Eckert number or channel half-angle increases, but it decreases as Reynolds number increases. On the other hand, it is also found that the presence of Cu nanoparticles in a water base fluid enhances heat transfer between nonparallel plane walls and in consequence the Nusselt number increases with the increase of nanoparticles volume fraction. Finally, an excellent agreement between analytical results and those obtained by numerical Runge-Kutta method is highly noticed.

Boundary Value Problems of Quasi-linear Ordinary Differential Equations on the Semi-infinite Interval

Existence of positive solution is established for boundary value problems of nonsingular for a class quasi-linear ordinary differential equation on the semi-infinite interval. The results are obtained by using the nonlinear alternative of Leray-Schauder method.

A New Method for Ride Quality Analysis of Vehicle

Current spectral analysis for evaluating the rail ride quality effectively is based on the sampling data at a uniform time interval, but the train is of fluctuation velocity in motion, which results in a non-uniform interval between consecutive sampling data. Therefore the accuracy of routine spectral analysis is in doubt when applying it in evaluating the rail ride quality. This paper presents a new way, namely, re-sampling with variable frequency to eliminate the influence of the train's uneven velocity. Its feature is that there is no need for precision measurement of the train's moving speed. Experiment results from the test-bed of rolling stock vibration show that it is valid.

Study on the Evaluation of the New Line of Urban Rail Transit Based on Analytic Hierarchy Process

The basic conditions of Urban rail transit line test operation are mainly based on Basic condition for trial operation of urban rail transit （GB/T30013-2013） the basic conditions of the relevant provisions, but the status and standard of trial operation of the basic conditions for assessment of the operating departments are still inadequate, during the three mouth of trial running operations, the specific work of trial operation and exercise are not clear about what this study focuses. This study emphasizes on the methods of operation assessment, through the Analysis Hierarchy Process （AHP） to make the commissioning work carry out smoothly and effectively, making the running exercise Rally, and the emergency and safety follow-up operation process can be quickly handled properly, and it is also helpful to the sustainable development of urban raft transit.

Study of Signal Processing Algorithm in the Receiving End of Through-the-Earth Communications of Elastic Wave

In the research of elastic wave signal detection algorithm, a method based on adaptive wavelet analysis and segmentation threshold processing of the channel noise removal methods is suggested to overcome the effect of noise, which is prcduced by absorption loss, scattering loss, reflection loss and multi-path effect during the elastic wave in the transmission undelgroound. The method helps to realize extraction and recovery of weak signal of elastic wave from the multi-path channel, and simulation study is carded out about wavelet de-noising effects of the elastic wave and obtained satisfactory results.

Calculation and Simulation Design of a Novel LED Light

Presented is a convenient and timesaving design method for illuminating light being used as a pint-sized searchlight usually,based on white light emitting diode(LED) source.The process of design is studied mostly in advanced system analysis program(ASAP).The analyses on this kind of design method reveal the factors that would affect the luminous flux distribution of light,including the number of LED chips,the focus of reflecor and refractor,the corresponding position of reflector and refractor with the source.The zone cofficient method and point-by point method are discussed respectively to determine the LED source and the illuminace distribution of light.The desired parallel light output is gained after being optimized in ASAP at last.

A design method and numerical study for a new type parabolic trough solar collector with uniform solar flux distribution

The non-uniform concentrated solar flux distribution on the outer surface of the absorber tube can lead to large circumferential temperature difference and high local temperature of the absorber tube wall,which is one of the primary causes of parabolic trough solar receiver(PTR)failures.In this paper,a secondary reflector used as a homogenizing reflector(HR)in a conventional parabolic trough solar collector(PTSC)was recommended to homogenize the solar flux distribution and thus increase the reliability of the PTR.The design method of this new type PTSC with a HR was also proposed.Meanwhile,the concentrated solar flux distribution was calculated by adopting the Monte Carlo ray-trace(MCRT)method.Then,the coupled heat transfer process within the PTR was simulated by treating the solar flux calculated by the MCRT method as the heat flux boundary condition for the finite volume method model.The solar flux distribution on the outer surface of the absorber tube,the temperature field of the absorber tube wall,and the collector efficiency were analyzed in detail.It was revealed that the absorber tube could almost be heated uniformly in the PTSC with a HR.As a result,the circumferential temperature difference and the maximum temperature could be reduced significantly,while the efficiency tended to decrease slightly due to the inevitably increased optical loss.Under the conditions studied in this paper,although the collector efficiency decreased by about 4%,the circumferential temperature difference was reduced from about 25 to 3 K and the maximum temperature was reduced from667 to 661 K.

Effects of Relativistic and Ponderomotive Nonlinearities on an Intense Laser Pulse Propagation in a Plasma Channel

The optical guiding of a moderately intense laser pulse in a parabolic preformed plasma channel is analyzed by means of the variational method.Relativistic,ponderomotive and their coupling nonlinearities are included.The conditions for periodic defocusing and focusing,as well as constant spot size propagation are given.It is found that the laser focusing is released by the coupling of relativistic and ponderomotive nonlinearities.

A POSTERIORI ERROR ANALYSIS FOR A FULLY DISCRETE DISCONTINUOUS GALERKIN APPROXIMATION TO A KIND OF REACTIVE TRANSPORT PROBLEMS

In order to obtain an expected numerical solution, a fully discrete discontinuous Galerkin method is applied to a kind of reactive transport problems in two dimension. That is to say, the space variable is discretized with the symmetric interior penalty Calerkin method （SIPG）, and the time variable is done with the backward Euler method. Making use of the duality technique, hp approximation properties and the interpolation theory, a residual-type a posteriori error estimation is achieved, which can be used for adaptivity. Compared with the analyses of semi-discretization, the current presentation is more challenging and more significant.

Building Communication Capacity for Good Governance： A Multi-leveled Analysis

This paper stresses the role of media and communication in promoting good governance by presenting a multi-leveled analytical approach to issues and cases both nationally and internationally. The study draws policy implications for the Chinese government as regards to integrating building communication capacity into governance agenda. Even though there is a growing attention on implementing communication programs into policies, the study on the role of the media and communication in governance has not been dearly conceptualized. This 15aper analyses the role of media and communication in promoting good governance from the levels of state governments, civil society and the general public, respectively. It argues that strong communication capacity at the governmental level increases governance effectiveness through helping to build consensus in policy-making and promote development policies; strong communication capacity of the civil society expands the development results when the NGOs work together with the mass media to promote their activities and prioritize development goals through media＇s agenda-setting and framing functions; and strong communication capacity strengthens the voice of the public and empower them to hold the government account through the media＇s watch-dog role. The paper concludes that improving communication capacity is essential to achieve good governance for the Chinese government.