Search

Detecting and counting vehicles in transportation surveillance videos are essential for applications ranging from traffic queue detection to incident and vehicle identification. In this paper, we propose a vehicle counting method based on Single Shot MultiBox Detector (SSD). We perform vehicle detection, vehicle tracking and counting tasks via SSD. The SSD has the capacity to extract meaningful features of blob of vehicles, and predicting the location and classification of vehicles. Tracking moving vehicles can be achieved by comparing the blob of vehicles and measuring the minimal distance between two temporal pictures. Furthermore, given that the virtual coil method is easy to implement, we utilize this method to count the number of moving vehicles with fast speed. Finally, the experiment results are provided to illustrate that the effectiveness of the proposed method on counting vehicles with above 87% accuracy of real-time processing speed.

To analyze whether different hepatitis B virus (HBV) infection status influenced the prognosis of patients with lupus nephritis (LN) under immunosuppressive therapy.A retrospective study enrolled 177 adults with active LN (Classes III, IV, V or mixed), and divided them into three groups: (i) HBV-free group (n = 93), antibodies to hepatitis B surface antigen positive only or all items negative; (ii) occult HBV infection group (n = 68), hepatitis B surface antigen (HBsAg) negative and antibody to hepatitis B core antigen positive with undetectable HBV DNA; and (iii) HBV infection group (n = 16), HBsAg-positive. The composite renal outcome was defined as a composite of progression to end-stage renal disease, 50% estimated glomerular filtration rate decrease, or death.The HBV infection rate was 9.04% in active LN. In the HBV infection group, a greater proportion of patients delayed immunosuppressive therapy, reduced prednisone dose, used mycophenolate mofetil in the first induction phase, received immunoglobulin pulse therapy, as well as avoided methylprednisolone pulse treatment (P 0.05). The composite renal outcome was significantly different among the three groups: 4/93 (4.30%) of the HBV-free group, 7/68 (10.29%) of the occult HBV infection group, and 4/16 (25.00%) of HBV infection group (P = 0.018). Univariate and multivariate analyses identified three independent risk factors of composite renal outcome: active HBV carrier (odds ratio [OR] 10.342, 95% CI 2.151-66.053, P = 0.017), cycle of immunosuppression 1 (OR 3.345, 95% CI 1.201-9.983, P = 0.025), and delayed immunosuppressive therapy (OR 3.118, 95% CI 1.207-10.662, P = 0.031).All these results suggested that HBV infection status might confer a worse prognosis for patients with active LN.

This paper proposes a fusion algorithm based on explicit complementary filter (ECF) and Kalman filter using open source autopilot controller to realize flight of indoor quadrotor UAV in the environment of motion capture system (i.e. Optitrack). The fusion algorithm establishes the state equation model of the system based on the attitude angle differential equation. The attitude angle after ECF is used as the observation of the system, and then the extended Kalman filter (EKF) algorithm is used to fuse the measured data of gyroscope, Optitrack, accelerometer and magnetometer. To verify the effectiveness of the algorithm, static and dynamic flight experiments are conducted indoors with the Optitrack environment using a UAV equipped with an IMU. The experimental results show that the fusion algorithm can restrain the attitude angle drift and filter out the noise well when placed in static state, and can track the change of the attitude of the UAV quickly in flight, which improves the attitude angle accuracy of estimation.

A novel type of trivalent BNg five-membered cational species B5Ngn3+(Ng = He~Rn, n = 1~5) has been found and investigated theoretically using the B3LYP and MP2 methods with the def2-QZVPPD and def2-TZVPPD basis sets. The geometry, harmonic vibrational frequencies, bond energies, charge distribution, bond nature, aromaticity, and energy decomposition analysis of these structures were reported. The calculated B−Ng bond energy is quite large (the averaged bond energy is in the range of 209.2~585.76 kJ mol-1) for heavy rare gases and increases with the Ng atomic number. The analyses of the molecular wavefunction show that in the BNg compounds of heavy Ng atoms Ar~Rn, the B−Ng bonds are of typical covalent character. Nuclear independent chemical shifts display that both B53+ and B5Ngn3+(n=1~5) have obvious aromaticity. Energy decomposition analysis shows that these BNg compounds are mainly stabilized by the σ-donation from the Ng valence p orbital to the B53+ LUMO. These findings offer valuable clues toward the design and synthesis of new stable Ng-containing compounds.

A novel type of trivalent BNg five-membered cational species B

Phasor measurement units (PMUs) are becoming an important component in the power grid. The PMUs provide time-synchronized measurements of multiple remote measurement points, enabling more accurate and real-time monitoring of the system state. Heuristically, it is difficult to tell how the placement of a PMU at a specific location in the power system would affect the state estimation error, not to say the effect of the PMU synchronization and measurement accuracy. In this paper, we derive the posterior Cramer-Rao bound (PCRB) on the state estimation error based on a measurement model which considers the phase-angle mismatch from PMU measurements. We then propose a PMU placement strategy using the derived PCRB. The greedy algorithm is used to solve the optimization problem. The results are then compared with other heuristics, with the optimal solution through an exhaustive search (for small systems), and with a lower bound on the optimal placement obtained through convex relaxation. For some design criteria, the objective functions are submodular, which guarantees a performance bound on the greedy solution. For other design criteria where the objective functions are not submodular, numerical examples demonstrate the effectiveness of the greedy algorithms.

For the dynamics of spins in an inhomogeneous classical continuum biquadratic Heisenberg ferromagnetic spin chain with the deformation of the inhomogeneous Heisenberg ferromagnetic spin system through a space curve formalism, we work on the behavior of solitons described by a generalized inhomogeneous higher-order nonlinear Schrodinger equation. Upon the introduction of an auxiliary function, bilinear forms, analytic one- and two-soliton solutions are derived via the Hirota method. We find that the inhomogeneous parameters can affect the amplitude of the soliton, and also see the existence of explode–decay soliton. Asymptotic analysis is carried out on the two-soliton solutions. Effects of the linear inhomogeneities on the one and two solitons are investigated graphically and analytically. Soliton amplitude and peak position are related to the inhomogeneous coefficients of the equation. Interaction between two solitons follows the attraction–repulsion process.

boron carbide–cerium boride porous composites are prepared by hot pressed sintering, and mechanical properties and microstructure of boron carbide–cerium boride porous composites were tested. The results show that Flexibility strength of B4C-CeB6 porous composites is greatly improved compared with that of monolithic porous boron carbide. B4C react with CeO2 to completely form CeB6 in porous composites. CeB6 particles in B4C grain boundary are produced by in-situ reaction. The presence of CeB6 reinforcing particles could also suppress growth of B4C grains which normally leads to improved strength.

B4C-CeB6 porous composites are prepared by hot pressed sintering between 1900°C and 2000°C, and mechanical properties and phase composition of B4C-CeB6 porous composites were tested. The results show that the porous rate of B4C-CeB6 porous composites ranges between 30%-48% at sintering temperate 1900°C-2000°C. Porous rate of B4C-CeB6 porous composites is decreased with temperature be increased. Flexibility strength of B4C-CeB6 porous composites is greatly improved compared with that of monolithic porous boron carbide. B4C react with CeO2 to completely form CeB6 in porous composites.

We consider the problem of direction of arrival (DOA) estimation using a newly proposed structure of non-uniform linear arrays, referred to as co-prime arrays, in this paper. By exploiting the second order statistical information of the received signals, co-prime arrays exhibit O(MN) degrees of freedom with only M + N sensors. A sparsity based recovery method is proposed to fully utilize these degrees of freedom. Unlike traditional sparse recovery methods, the proposed method is based on the developing theory of super resolution, which considers a continuous range of possible sources instead of discretizing this range into a discrete grid. With this approach, off-grid effects inherited in traditional sparse recovery can be neglected, thus improving the accuracy of DOA estimation. In this paper we show that in the noiseless case one can theoretically detect up to M N sources with only 2M + N sensors. The noise 2 statistics of co-prime arrays are also analyzed to demonstrate the robustness of the proposed optimization scheme. A source number detection method is presented based on the spectrum reconstructed from the sparse method. By extensive numerical examples, we show the superiority of the proposed method in terms of DOA estimation accuracy, degrees of freedom, and resolution ability compared with previous methods, such as MUSIC with spatial smoothing and the discrete sparse recovery method., Comment: Submitted on December 17th, 2013

Pedestrian detection plays a pivotal role in various domains but is still a challenging problem nowadays. In this study, we transform the multiple-pedestrian detection problem into a multimodal optimization problem and then utilize a multimodal estimation of distribution algorithm (MEDA) to optimize this problem based on Histograms of Oriented Gradients (HOG) feature and Support Vector Machines (SVM). Specifically, we adopt a three-dimensional vector to represent a rectangular region of an image and also use it to encode individuals. Then, a state-of-the-art multimodal optimization algorithm called MEDA is utilized to evolve the individuals, so that a series of optimal rectangular regions containing pedestrians can be obtained. Experiments conducted on a set of images from one pedestrian dataset called INRIA confirm that in comparison with the classical HOG-SVM method and one state-of-the-art method, the developed algorithm cannot only achieve higher detection accuracy on images containing different numbers of pedestrians, but also can remain high computational efficiency.

A series of new 1-(carbamoylmethyl)-2-aryl-3,1-benzoxazines were prepared in moderate to good yields by BF3·OEt2-catalyzed reactions of aromatic aldehydes with 2-(N-substituted carbamoylmethylamino)benzyl alcohols. The structures of the target compounds were confirmed by IR, 1H-NMR, 13C-NMR, and elemental analyses. The fungicidal activities of the target compounds against plant fungi were preliminarily evaluated, and some of them exhibited good activity.

Tracking-Learning-Detection (TLD) is an excellent long-term tracking method which has the advantages of high accuracy of tracking rate and self-detection mechanism. Noting that TLD algorithm is sensitive to illumination change and clutter results in drift even missing, and the corresponding tracker designed based on the pyramid Lucaks-Kanade optical flow method needs vast computation. To overcome these shortcomings, an improved target tracking scheme by integrating mean-shift and TLD algorithm is proposed. The designed scheme improves the ability of resistance to shade and increases the processing speed through setting the reasonable iterative starting point of mean-shift algorithm. Meanwhile, by combining self-detection with on-line learning mechanism, we can solve the problem of goals lost in tracking process. Finally, experimental results are provided to demonstrate that the proposed method can properly detect and accurately track a target in complex scenes.

Previous work on dialog act (DA) classification has investigated different methods, such as hidden Markov models, maximum entropy, conditional random fields, graphical models, and support vector machines. A few recent studies explored using deep learning neural networks for DA classification, however, it is not clear yet what is the best method for using dialog context or DA sequential information, and how much gain it brings. This paper proposes several ways of using context information for DA classification, all in the deep learning framework. The baseline system classifies each utterance using the convolutional neural networks (CNN). Our proposed methods include using hierarchical models (recurrent neural networks (RNN) or CNN) for DA sequence tagging where the bottom layer takes the sentence CNN representation as input, concatenating predictions from the previous utterances with the CNN vector for classification, and performing sequence decoding based on the predictions from the sentence CNN model. We conduct thorough experiments and comparisons on the Switchboard corpus, demonstrate that incorporating context information significantly improves DA classification, and show that we achieve new state-of-the-art performance for this task.

The effect of heat treatment on the microstructure and mechanical properties of High Strength steel plate Q960E for construction machinery was investigated. The result shows the quenching temperature have obvious effects on the mechanical properties, DQ can improve the toughness and the enchance tempering resistance, precipitations become more and bigger with the rise of the tempering temperature.

We design a double quantum-dot (QD) shuttle (DQDS) model including two rigidly connected QDs that are softly linked to two leads via deformable organic materials. Based on the full quantum mechanical approaches we explore the influences on the electron transport induced by the electrical and mechanical degrees of freedom. First of all the modified rate equations of the DQDS are derived theoretically and then a numerical investigation on the quantum transport through the DQDS is performed. For the classical DQDS, the time-dependent evolutions of the electron-occupation probabilities and the currents flowing through the DQDS show the periodic oscillations with their periods determined by the oscillation period of the DQDS. Both the mechanical oscillation amplitude and the interdot coupling can play crucial roles in adjusting the peak shapes of the currents and the probabilities. For the quantum DQDS, the current and electron-occupation probabilities of the DQDS evolve into a stationary state as time goes on, with no periodical oscillations observed. As a consequence, the sharp differences of the time-dependent properties between the classical and quantum DQDS systems are clearly demonstrated, which should be greatly helpful in designing new nanoelectromechanical devices. Also, this work is of great significance to understanding the kind of rigidly connected QD shuttle systems that have more than two QDs.

We consider algorithms and recovery guarantees for the analysis sparse model in which the signal is sparse with respect to a highly coherent frame. We consider the use of a monotone version of the fast iterative shrinkage- thresholding algorithm (MFISTA) to solve the analysis sparse recovery problem. Since the proximal operator in MFISTA does not have a closed-form solution for the analysis model, it cannot be applied directly. Instead, we examine two alternatives based on smoothing and decomposition transformations that relax the original sparse recovery problem, and then implement MFISTA on the relaxed formulation. We refer to these two methods as smoothing-based and decomposition-based MFISTA. We analyze the convergence of both algorithms, and establish that smoothing- based MFISTA converges more rapidly when applied to general nonsmooth optimization problems. We then derive a performance bound on the reconstruction error using these techniques. The bound proves that our methods can recover a signal sparse in a redundant tight frame when the measurement matrix satisfies a properly adapted restricted isometry property. Numerical examples demonstrate the performance of our methods and show that smoothing-based MFISTA converges faster than the decomposition-based alternative in real applications, such as MRI image reconstruction., Submitted on Aug 22th, 2013; Updated on Dec 1st, 2013

In this paper, we propose a new model of demand response management for the future smart grid that integrates plug-in electric vehicles and renewable distributed generators. A price scheme considering fluctuation cost is developed. We consider a market where users have the flexibility to sell back the energy generated from their distributed generators or the energy stored in their plug-in electric vehicles. A distributed optimization algorithm based on the alternating direction method of multipliers is developed to solve the optimization problem, in which consumers need to report their aggregated loads only to the utility company, thus ensuring their privacy. Consumers can update their loads scheduling simultaneously and locally to speed up the optimization computing. Using numerical examples, we show that the demand curve is flattened after the optimization, even though there are uncertainties in the model, thus reducing the cost paid by the utility company. The distributed algorithms are also shown to reduce the users' daily bills.

Using the Hartree Fock (RHF) method, we study the most reactive carbon atoms in the polycyclic aromatic hydrocarbons (PAHs). In order to identify the most reactive carbon atoms, the Mulliken charges and the Mayers bond orders were calculated as the criterion. The results demonstrate that the most reactive carbon atoms appear at the locations of the outer C in the inner benzene rings for cata-condensed PAHs, while for peri-condensed PAHs they are the outer C in the outer benzene rings。

Phasor measurement units (PMUs) are time synchronized sensors primarily used for power system state estimation. Despite their increasing incorporation and the ongoing research on state estimation using measurements from these sensors, estimation with imperfect phase synchronization has not been sufficiently investigated. Inaccurate synchronization is an inevitable problem that large scale deployment of PMUs has to face. In this paper, we introduce a model for power system state estimation using PMUs with phase mismatch. We propose alternating minimization and parallel Kalman filtering for state estimation using static and dynamic models, respectively, under different assumptions. Numerical examples demonstrate the improved accuracy of our algorithms compared with traditional algorithms when imperfect synchronization is present. We conclude that when a sufficient number of PMUs with small delays are employed, the imperfect synchronization can be largely compensated in the estimation stage.

In the biased guest-host photorefractive polymer, the Manakov equations can be used to describe the optical soliton propagation and interaction. Hereby for such equations, via the Hirota method and symbolic computation, analytic soliton solutions in the bright-dark and dark-dark forms are obtained. Based on the choice of photorefractive polymer parameter and incident-optical-beam parameter, the bright-dark and dark-dark solitons as well as their interaction can occur in the polymer when the total intensity is much lower than the background illumination, and our analysis indicates that the incident light with different polarization directions influence little on the soliton propagation. γ, representing the soliton intensity far away from the soliton center, determines the appearance of bright or dark soliton under the background illumination. Through the graphic and asymptotic analysis on the two-soliton solutions along with the different γ, we find that there exist the elastic and inelastic interactions between the bright-dark solitons, while the interactions between the dark-dark solitons are always elastic.

To drive the application of surface-enhanced Raman spectroscopy (SERS) mapping in ex vivo diagnostic imaging and non-biological material characterization, we have designed a robust and accurate multiplex spectral fitting method using an alternating minimization algorithm to extract individual constituent Raman spectra with very small overall fitting error (as low as 2%). For each mixed Raman signal, constituent spectra and mixture coefficients were estimated jointly based on reference spectra that were measured in the lab. Our method is based on a Poisson model to reflect the photon counting nature of Raman signals and includes the nonlinear noise in the measured data, making our method robust against data containing relatively large random noise. In our method, we minimized a cost function consisting of two terms: (1) the overall fitting error between the measured and modeled spectra and (2) the sum of the individual error between each reference spectrum and its corresponding constituent. This method inherently guarantees that the estimates will approach the global minimum with monotonic convergence. The accuracy of our method was validated by applying it to a SERS spectral fitting problem and comparing our results to those from existing methods. Copyright © 2013 John Wiley & Sons, Ltd.

Objective To explore the influence of obstructive sleep apnea syndrome (OSAS) on blood glucose control and chronic diabetic complications in type 2 diabetes patients. Methods The type 2 diabetes patients hospitalized in 307 Hospital of PLA from September 2011 to July 2012 were screened for OSAS with a portable sleep respiration monitor ApneaLinkTM device. According to screening results mentioned above, patients were divided into two groups as OSAS group and control group, whose fasting blood glucose level, 2-h postprandial blood glucose level, HbA1c level, HOMA-IR index and prevalence of diabetic retinopathy (DR), and incidences of diabetic nephropathy (DN), diabetic peripheral neuropathy (DPN), hypertension, and hyperlipidemia were recorded and analyzed for evaluating the relationship between OSAS severity and aforesaid factors. Results One hundred and forty-five patients completed the protocal with 114 cases (87 males and 27 females) stratified in OSAS group and 31 cases (22 males and 9 females) in control group. Compared with control group, the average fasting blood glucose level, 2-h postprandial blood glucose level, HbA1c level and HOMA-IR index were significantly higher in OSAS patients (P

The electronic properties of pristine and compressed bulk black phosphorus (BP) in the presence of a magnetic field perpendicular to a BP monolayer are investigated by using the tight-binding Hamiltonian model. Similar to that of graphite, the magnetic field can induce the flat, partially flat, and oscillatory Landau levels (LLs) in both kinds of BP, although there exist many distinct properties different from graphite, such as the oscillatory LL positions and the LL spacings. Also, the LLs exhibit richer dependences on the LL index, including a quadratic (linear) function of the LL index for the small (big) LL index. Furthermore, the topological node-line semimetal state in compressed BP caused by the strain is found to be sensitive to the magnetic field, indicating that even a very weak magnetic field is enough to break the node-line state. Meanwhile, it is shown that the strain can almost uniformly increase the LL spacing for the conductance band, while a different and complex LL spacing variation is observed for the valence band.

The aim of this study is to investigate the prevalence and risk factors for hepatitis B virus (HBV) reactivation in HBsAg-negative/HBcAb-positive patients receiving immunosuppressive therapy for glomerulonephritis. We performed a retrospective study of 745 HBsAg-negative/HBcAb-positive patients undergoing immunosuppressive therapy for glomerulonephritis from years 2003 to 2012 at the department of nephrology, China-Japan Friendship Hospital, Beijing, China. The patients were divided into HBV reactivation group (n = 27) and non-HBV reactivation group (n = 718). The prevalence of HBV reactivation in patients receiving immunosuppressive therapy for glomerulonephritis was up to 3.62% in serological status of HBsAg-negative/HBcAb-positive. HBV reactivation was associated with several findings: greater proportion of lupus nephritis (25.93 vs. 9.61%, p = 0.014), much higher percentage of HBsAb-negative (74.07 vs. 23.82%, p

Much empirical evidence shows that individuals usually exhibit significant homophily in social networks. We demonstrate, however, skill complementarity enhances heterophily in the formation of collaboration networks, where people prefer to forge social ties with people who have professions different from their own. We construct a model to quantify the heterophily by assuming that individuals choose collaborators to maximize utility. Using a huge database of online societies, we find evidence of heterophily in collaboration networks. The results of model calibration confirm the presence of heterophily. Both empirical analysis and model calibration show that the heterophilous feature is persistent along the evolution of online societies. Furthermore, the degree of skill complementarity is positively correlated with their production output. Our work sheds new light on the scientific research utility of virtual worlds for studying human behaviors in complex socioeconomic systems.

Thermo-mechanical simulation tests were performed on V–Ti–N microalloyed steel under three hot working conditions by using Gleeble-3800 thermo-mechanical simulator to study the effects of hot deformation and post-deformation holding process on the continuous cooling transformation behaviors of overcooled austenite. The continuous cooling transformation diagrams (CCT diagrams) were determined by thermal dilation method and metallographic method. The effects of the hot deformation, post-deformation holding, and cooling rate on the microstructure evolution were analyzed. The results show that deformation promotes ferrite and pearlite transformation. In addition, deformation leads to an increase in bainite start temperature, which becomes more markedly with the increase in cooling rate. The post-deformation holding process is much favorable to promote carbonitride precipitation of the microalloying elements, which contributes to ferrite nucleation and smaller austenite grains. As a result, an increase in ferrite quantity and a decrease in ferrite grain size can be observed. And further more, the post-deformation holding process reduces the effect of hot deformation on the bainite start temperature.

Kondo transport properties through a Kondo-type quantum dot (QD) with a side-coupled triple-QD structure are systematically investigated by using the non-equilibrium Green's function method. We firstly derive the formulae of the current, the linear conductance, the transmission coefficient, and the local density of states. Then we carry out the analytical and numerical studies and some universal conductance properties are obtained. It is shown that the number of the conductance valleys is intrinsically determined by the side-coupled QDs and at most equal to the number of the QDs included in the side-coupled structure in the asymmetric limit. In the process of forming the conductance valleys, the side-coupled QD system plays the dominant role while the couplings between the Kondo-type QD and the side-coupled structure play the subsidiary and indispensable roles. To testify the validity of the universal conductance properties, another different kinds of side-coupled triple-QD structures are considered. It should be emphasized that these universal properties are applicable in understanding this kind of systems with arbitrary many-QD side structures.

Using the tight-binding Hamiltonian approach, we theoretically study the electronic and optical properties of a triangular phosphorene quantum dot (PQD) including one normal zigzag edge and two skewed armchair edges (ZAA-PQD). It is shown that the energy spectrum can be classified into the filled band (FB), the zero-energy band (ZB), and the unfilled band (UB). Numerical calculations of the FB, ZB, and UB probability distributions show that the FB and the UB correspond to the bulk states, while the ZB corresponds to the edge states, which appear on all of the three edges of the ZAA-PQD sharply different from the other PQDs. We also find that the strains and the electric fields can affect the energy levels inhomogeneously. Then the optical properties of the ZAA-PQD are investigated. There appear some strong low-energy optical absorption peaks indicating its sensitive low-energy optical response that is absent in other PQDs. Moreover, the strains and the electric fields can make inhomogeneous influences on the optical spectrum of the ZAA-PQD. This work may provide a useful reference for designing the electrical, mechanical, and optical PQD devices.

Massive multiplayer online role-playing games (MMORPGs) are very popular in past few years. The profit of an MMORPG company is proportional to how many users registered, and the instant number of online avatars is a key factor to assess how popular an MMORPG is. We use the on-off-line logs on an MMORPG server to reconstruct the instant number of online avatars per second and investigate its statistical properties. We find that the online avatar number exhibits one-day periodic behavior and clear intraday pattern, the fluctuation distribution of the online avatar numbers has a leptokurtic non-Gaussian shape with power-law tails, and the increments of online avatar numbers after removing the intraday pattern are uncorrelated and the associated absolute values have long-term correlation. In addition, both time series exhibit multifractal nature., Comment: 9 Elsart pages including 7 figures