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Small period long period fiber grating is fabricated by femtosecond laser line by line technique. High order Bragg resonances, which are useful for dual-/multi- parameter sensing, are significantly enhanced (from ~0.6 dB to ~11 dB).

To accommodate distributed renewable energy and improve energy efficiency, it is necessary to develop the integrated energy system (IES). However, high construction costs and complex operation optimization are crucial obstacles to the development of IES on user side. The optimal operation of IES can excavate more flexibility for power system and reduce its operating costs through providing demand response (DR) services in the power market. Therefore, this paper proposes the operating models for equipment in IES considering DR and the optimization method to schedule the operation and DR capacity simultaneously in the power market. Then, the proposed nonconvex model is mathematically transformed into a solvable mixed integer linear programming (MILP) problem. Experimental results tested on a realistic IES indicate the effectiveness of the proposed model.

With the development of renewable energy sources (RES), the safe and stable operation of the power system is facing a new challenge. Because of the intermittency and fluctuation of RES, more regulation resources are needed to alleviate the threat to the power system. Compared with traditional generation units, large-scale flexible loads at demand side can provide huge regulation potential for accommodating RES by demand response (DR), such as air conditioners (ACs), electric vehicles (EVs), energy storage systems (ESSs). The models of large-scale flexible loads are developed firstly, based on their operating characteristics, including individual loads and aggregated loads. Meanwhile, a control strategy is proposed to allocate the flexible loads reasonably according to different regulation targets, e.g. peak shaving and valley filling and suppressing the tie-line fluctuation, considering renewable energy accommodation. Finally, several cases are studied to show the performance of the control strategy, based on the real photovoltaic data. The results prove the efficiency of DR by large-scale flexible loads. The irregular fluctuations are reduced by 90 percent, and the peakvalley difference decreases from 457kW to 276kW, which are beneficial to the stable and economic operation of the power system. Besides, large-scale flexible loads can also provide operating reserve, about 4.3% loads of the peak power will be cut down during the power shortage period.

The rapidly increasing renewable energy sources (RESs) in the power system bring a large number of disturbances due to the intermittent and random characteristics of power generation. At the same time, most of the RES units are composed of power electronic devices, which can reduce the system inertia and impact the stable operation of the power system. Therefore, more operating reserve resources are required to participate in the rapid regulation in the power system with a high proportion of RES. The rapid development of information and communication technologies make it easier and lower cost to control flexible loads. Based on the new network resources, for example, 5G, flexible loads can be regulated rapidly to participate in power system frequency control. In this paper, the models, categories, and functions of typical flexible loads are analyzed. Then, the research status of various flexible loads for participating in frequency regulation (FR) is combed in detail. On this basis, the advantages and disadvantages of various load control methods and their application scenarios are discussed. Finally, the development prospects of flexible loads for FR are proposed, so as to provide references for practical application.

With the development of the information and communication technologies, demand response (DR) can be realized more easily and considered as one of effective methods to provide regulation services for the power system. Among the flexible loads for DR, thermostatically controlled loads (TCLs) are regarded as one of the most important loads, because of the large share of power consumption and suitable regulation characteristics without impacting customers’ comfort. However, the dispatching potential of TCLs is difficult to be evaluated due to the limitation of measuring equipment. Faced with this issue, this paper proposes a method for evaluating the dispatching potential of TCLs based on the realistic customer electricity data in China. The relationship between the dispatching potential of TCLs and the ambient temperature is obtained. In this way, the system operator can calculate the dispatching potential of TCLs according to the weather forecast. The effectiveness of the proposed model and method is verified in the case studies.

This paper proposes state-of-charge (SOC) balancing control based on discrete consensus algorithm to improve the accuracy of power dispatch of the battery energy storage systems (BESS), reducing system cost and prolong the service life of the BESS in islanded microgrid. This has been achieved with hierarchical distributed secondary cooperative control based on discrete consensus algorithm, which modifies the BESS output power to reach a balanced SOC. The control structure has two layers. The cooperative control works as the secondary layer, obtaining equal SOC of the BESS of the grid through interchanges information of energy storage systems state of charge (SOC) with its neighbors. BESS control approach as the primary control layer, they are able to realize the output power sharing and the balancing discharge rate by regulating the virtual resistance. The simulation platform is built based on Matlab/Simulink software. The validity and feasibility of the proposed control strategy has been further verified by various simulation results.

An asymmetrical dual-core photonic crystal fiber (DC-PCF), which possesses all circular air holes, is proposed. By setting appropriate geometrical parameters, the wavelength-selective coupling property is realized, and a compact optical filter with a short length of 1.83 mm based on the DC-PCF is designed. The spectral transmission characteristics of the filter are investigated by the beam propagation method. The results demonstrate that the optical filter possesses a bandwidth of ∼ 58 nm and small sidelobes. The proposed optical filter could be used in the integrated optical systems.

One critical challenge of today's cloud services is how to provide an effective search service while preserving user privacy. In this paper, we propose a wildcard-based multi-keyword fuzzy search (WMFS) scheme over the encrypted data, which tolerates keyword misspellings by exploiting the indecomposable property of primes. Compared with existing secure fuzzy search schemes, our WMFS scheme has the following merits: 1) Efficiency. It eliminates the requirement of a predefined dictionary and thus supports updates efficiently. 2) High accuracy. It eliminates the false positive and false negative introduced by specific data structures and thus allows the user to retrieve files as accurate as possible. 3) Flexibility. It gives the user great flexibility to specify different search patterns including keyword and substring matching. Extensive experiments on a real data set demonstrate the effectiveness and efficiency of our scheme.

In cloud computing, a data owner outsources a huge dataset to cloud servers, and authorizes many clients to retrieve data of interest anytime and anywhere. Data outsourcing is helpful to lessen the burden on local data storage and also to improve quality of services. However, the cloud service provider (CSP) outside the data owner’s trusted domain may return wrong query results to the client deliberately or inadvertently.Therefore, query authentication and query correction are of crucial importance to achieve reliable cloud services. In this paper,we consider a flow-oriented cloud environment, where query results will be transmitted in the form of data flow to the clients via networks. Specifically, we propose a two-phase query (TPQ) protocol to support efficient authentication and correction of multi-dimensional range queries. By ingeniously integrating signature chain with Reed Solomon codes, our proposed protocol allows a client to efficiently verify the correctness of query results while performing error correction in an adaptive way. Extensive experiments on a real dataset demonstrate effectiveness of our proposed protocol.

In China stock market, more than 95% are non-professional investors. Due to the lack of professional skill and the complexity of financial indicators and the varying investment environment, non-professional investors are in great need of a data mining-based intelligent stock trading decision-support system. Considering the existence of concept drift phenomenon, this study proposes an adaptive learning process with the Lasso algorithm-based feature selection. Moreover, we use support vector machine as stock market predictor for stock selection and a risk-adjusted method for portfolio optimization. Finally, a web-based Adaptive Risk-adjusted Intelligent Stock Trading System (iTrade) is established. The seven-year (2005-2011) back-testing shows that our system can generate much higher cumulative return than the benchmark (Shanghai Composite Index) in China stock market. Meanwhile, concept drift analysis of adaptive relevant variable discovery process has revealed contrasting historical trends between two selected industries. In conclusion, the iTrade is suitable for non-professional investors in portfolio management, following the varying stock market environment and providing effective guidance.

In supply chain management, it is conventional for the customer to use quality contracts and punishment to control its supplier's opportunistic behavior and ensure quality. However, this mechanism is reactive and its effects are hardly satisfactory. In this study, we are interested in introducing a new mechanism into supply chain quality management — information transparency. A principal-agent model is formulated to investigate the impacts of sampling inspection and information transparency on supply chain quality management. It is shown that the combined use of the two mechanisms can significantly improve the supply chain performance compared to using either of the mechanisms alone.

It requires a comprehensive concept of modern information technology to further advance the course reform in the context of information culture, which mainly contains three ways. In essence, it requires to make a shift from the concept of information technology as a tool to the concept of information technology as the culture.

In this paper, a compact beam splitter is proposed for terahertz (THz) systems based on the self-collimation effect in two-dimensional photonic crystals (PCs). The splitter has a very compact size of 908×908μm2. The parameters of the splitter are optimized by using the plane wave expansion (PWE) method. The equal-frequency contours (EFCs) and gap map are given to analyze the properties of the splitter. By using the finite-difference time-domain (FDTD) method, the field distribution of the THz wave propagation in the structure is simulated and the normalized transmitted powers versus various radii of the air holes of the splitting region are calculated. The impact of incident angles on the transmitted power is also studied with the FDTD method.

We have analyzed (he transmission properties of guiding band in one-dimensional photonic crystal with periodic defect layers. Using transfer matrix method we concluded that the guiding band width would change with varying defect layer size or the distance between defect layers. The group velocities of different guiding bands were calculated and we found that the defect layer size could apparently affect the group velocity. We also discussed the properties of the defect modes resulted by another defect layer in the slow wave structure.

This paper demonstrates that light propagation in two dimensional square and hexagonal lattices photonic crystal (PhCs) behaves negative refraction effect in the vicinity of the photonic bandgaps. Plane wave expansion method was used to solve complex eigenvalue problems, as well as to plot dispersion curves and Equi-frequency surfaces (EFS). Theoretical simulating results have been presented, and all-angle negative refraction and superlensing effect have been versified.

At present, the application of Capsule endoscopy (CE) faces some extremely important issues, e.g., image quality and field of view, which causing difficulties for doctors to make an accurate diagnosis. It's a technical difficulty to acquire wide-angle internal intestinal image under the volume restrictions of CE. In this paper, a simple and practical design of CE lens aimed to clearer and wider-angle intestine image is proposed based on ZEMAX. The new lens improves the field curvature and distortion with the application of special transparent cover and aspheric technology. The optimal design has a FOV of 105 °, and the F number is 2.8. The modulation transfer function (MTF) is about 40% at 45lp/mm, and the distortion is under 15%. It can perfectly satisfy the requirements of the CE lens, and provide high-quality image for 1/4″ CMOS image sensor with effective pixels of 1600×1200 and pixel size of 2.2µm.

The CCD hardware circuit base on AD9923 of Analog Devices Company is presented. By comparing the internal main circuit module of AD9923A and AD9949, the advantages of using AD9923A is analyzed. Compare with the AD9949 scheme, it can be seen that using AD9923A to design the CCD driving circuit has simple hardware structure, low cost and high reliability. Through designing circuit, contrast test shows that using AD9923A has higher signal to noise ratio (SNR) than using AD9949.

This paper makes an analysis on the limitations existing in the practice of integration of information technology and academic courses and points out that the integration will necessarily change to a curriculum revolution of IT culture, that is, curriculum information. And it also puts forward the concept of curriculum information and defines its content, analyzes the association and its distinction from integration and points out the possibility to achieve curriculum information from the perspective of IT culture.

In the complex reality environment, License plate image may contain multiple plates. At this point, simply using grayscale or color image processing only is very difficult to achieve fast and accurate positioning. By full use of the multiple conditions such as color, edge features and veins, a new method of multi-objective, integrated color of license plate location has been put forward. Firstly, make the multi-color threshold quantization segmentation of color image, edge detection and morphology of its deal to get a candidate region, integration of the color code matrix diagram and quantify the length and width of the plate area fixed ratio to get the second candidate region, then in the second candidate region, judging the edge points on both sides of the diagonal with the color quantization value, verify the authenticity of the candidate regions. Through progressively filter the candidate region, and ultimately locate each license plate. The algorithm is full integration the advantages of the method based on color image processing, simple and effective, and have good positioning accuracy and engineering practicality.

On the basis of the variational approach, this paper examines the dynamics of a pulse in fibers with periodic dispersion and nonlinearity. With this approach, a set of couple different equations for the evolution of the pulse width and chirp are obtained. We annalyse the propagation of dispersion and nonlinearity-managed solitons. The result demonstrates that compared with only dispersion management, a dispersion and nonlinearity-managed soliton can propagate with higher quality. Significantly, when the propagation distance increases, the pulse width almost remains unchangeable.

Left hand materials are composite medium which have simultaneously negative permittivity and permeability. The tradition methods to artificial fabricate left hand materials are static, so the experiment devices to verify them are relatively simple. A novel approach is presented to synthesize left hand materials with negative refractive index in microwave band by incorporating periodic metallic wire array into yttrium iron garnet applied by external magnetic field. The effective permeability of yttrium iron garnet and the effective permittivity of periodic metallic wire array are synchronously negative under certain external magnetic field. Theoretically investigation and simulations have been done to test its microwave transmission property and negative refractive character and prove that it is left hand material. In this paper, experiment devices to test the novel left hand material sample are depicted. Transmission experimental and prism experimental methods and results are revealed. To verify the magnetic tunable property of the sample, a set of magnetic field generator is designed, by which a tunable homogenous magnetic field can be obtained. The experiment steps using these designed devices are set forth in detail.

A left handed metamaterial (LHM) with e = − e 0 and μ = − μ 0 is proposed and its properties are theoretically and numerically analyzed. The LHM is composed of ferrites to provide a negative permeability and a wire array to provide a negative permittivity. The parameter conditions of satisfying aforementioned properties are investigated. The analyzed results show that the LHM has a nearly perfect negative pass band with very small reflections and losses in the microwave frequencies and the negative pass band can be tuned by changing the applied magnetic field. This LHM can be applied to various areas such as microwave engineering areas. In this paper, the applications of the LHM including the microwave filter and phase shifter are discussed respectively.

The tunneling effect in a left handed metamaterial (LHM) consisting of ferrites and wire array is presented. The ferrites based LHM exhibits a near perfect transmission with very low losses and reflections due to the e = − e 0 and μ = − μ 0 . Based on the theoretical results of effective permeability and permittivity of the LHM, the parameter conditions of perfect tunneling effect through a LHM slab is analyzed. Numerically simulated results indicated that the tunneling effect can be found in the microwave frequencies and demonstrated aforementioned theoretical results very well.

Management of data quality has become the bottleneck for enterprises to upgrade their application of information technology (IT). Based on the theory of total quality management, this paper presents five influencing factors of data quality from the perspective of organizational management, namely top management support, capability on regulation and process management, business-IT alignment, staff participation and integration of information systems (IS). At the same time, this paper establishes a process model of influencing factors, and conducts an empirical analysis through a field study of 185 enterprises. The results show that the influence of five factors presents transfer characteristics clearly. Top management support has an effect upon the capability on regulation and process management, and business-IT alignment directly, while indirectly on staff participation and integration of IS. Capability on regulation and process management, and business-IT alignment exert a direct impact on staff participation and integration of IS, while indirectly on data quality. Staff participation and integration of IS shows a direct impact on data quality. Finally, this paper presents some suggestions on improving data quality.

Enterprises invest in information system with the expectation that it will contribute to performance, and members of the organization must use information system for it to make a contribution. However, first-line and middle Managers' resistance to change and unwilling to use information systems have become the bottleneck in IT application. In this paper, the key effect factors of the first-line and middle manager IT usage intention are analyzed by conducting the structural equation model with the sample size of 321. The results show that user attitude has important effect on the first-line and middle manager IT usage intention. Attitude is the mediator between the perceived usefulness and the intention, and attitude is also the mediator between the perceived ease of use and the intention. Perceived usefulness is the mediator between the perceived ease of use and the attitude. The paper provides explanations to the results, discusses the practical implications of the findings and suggests directions for future research.

Information system offers the potential for substantially improving enterprise performance, but enterprise performance gains are often obstructed by users' unwillingness to accept and use available systems. In this paper, whether TAM can explain the first-line and middle managerspsila IT usage intention is firstly tested by using the regression analysis method with the sample size of 156. The results show that attitude is the key effect factor of IT usage intention, perceived usefulness has no direct effect on the IT usage intention, attitude is the mediator between the perceived usefulness and the IT usage intention, perceived ease of use has no direct effect on the attitude, perceived usefulness is the mediator between the perceived ease of use and attitude, which is not completely followed to the TAM. The core perception variables in TAM do not predict use in this study. The paper discusses the implications of these findings and suggests directions for future research.

The radial impedance expressions utilized to match all boundaries of the perfect lens are presented. Moreover, the voltage distribution formulas can be used for the design of an equivalent infinite slab lens system, which is simulated using two- dimensional loaded L, C transmission line network for negative- refractive-index metamaterial and voltage generators along with the boundaries in interface region. Simulations for equivalent infinite slab lens system are carried out. The results for the voltage phase and amplitude distributions in the perfect equivalent infinite slab lens system with the properties of negative refraction and focusing demonstrate excellent cylindrical waves.

Under the fully matched condition, we present microwave-circuit simulation results of subwavelength imaging by a slab composed of L, C loaded transmission-line media with a source in it., and we have found that, although the single-interface lens composed of an negative refractive index medium and a positive refractive index medium are not involved in the growth of evanescent wave to achieve perfect imaging, such a slab with a source in it leads to growing evanescent voltage wave away from the source in the slab, thus enhancing the resolution of the images.

The aim of this paper is to design an efficient and fast immune evolution algorithm for solving path planning program of soccer robot. The idea is to accurately read the inherent drawbacks of existing immune algorithms (IA) and propose new techniques to resolve them. The basic features of IA dealt in this paper are: hypermutation mechanism, clone expansion, immune memory and several other features related to initialization and selection of candidate solution present in a population set. Dealing with the above-mentioned features we have proposed an improved immune evolution algorithm (IEA). The algorithm is described in detail and the simulation experiment is carried out. The effectiveness of the approach is shown by the experiment result.

Software project development has high failure rate. Software project risk management may gain a high rate of return in investment. Establishing an intelligent risk evaluation model for project will be valuable in the analysis and control of project risks. In this paper, we employed neural network (NN) and support vector machine (SVM) approaches to establish a model for risk evaluation in project development. In the model, the input is a vector of software risk factors that were obtained through interview with 30 experts, and the output is the final outcome of the project. The data for modeling were collected from 120 real software projects through questionnaires. The experiment shows the model is valid. Interestingly, SVM is a powerful supervised learning method, and some believe that it is a more promising classification method that may someday supercede NN. In our study, the standard neural network model had lower prediction accuracy compared to SVM due to its tendency in finding local optima. However, after attempt in optimizing the neural network model with genetic algorithm, the experimental results showed that our enhanced model surpassed SVM in performance.

A new non?periodic structure of coaxial Bragg fiber has been optimum designed to improve the guided out-flux transmit characteristics. The number of cladding medium layers can be reduced by the reasonable simplify design for the non-periodic cladding structure coaxial Bragg fiber, it can achieve better field confinement than Bragg fiber in the same cladding layers structure. The structure simplification for the cladding layers is useful for the fabrication of the fiber.

A new aspheric surface pre-collimation lenses system for the optical antenna of space laser communication has been optimum designed by optical design software CODE-V. Meanwhile, a Cassegrain antenna with aspheric surface has been designed. By the use of Visual C++, an optical system design software has been set up to analyze optical antenna for the space laser communication system, and some simulation results have been obtained.

In this paper, semiconductor laser beam collimation lenses system which can be used in space laser communication has been optimum simulated and designed. Some new design methods based on the geometrical optical theory have been discussed in details, and an ideal aspheric surface design method has been given. The optical system has been further simulated by optical design software CODE-V. The collimation laser beam divergence angles have been obtained by experimental measure with laser beam analyzer. Experimental test results showed that it can be achieved a good collimation effect. This optimum design laser beam collimation system can be widely used in modern space laser communication.