Abstract:

Abstract:

Abstract: Interactive evolutionary algorithms with user preference implicitly extracted from interactions of user are more powerful in alleviating user fatigue and improving the exploration in personalized search or recommendation. However, the uncertainties existing in user interactions and preferences have not been considered in the previous research, which will greatly impact the reliability of the extracted preference model, as well as the effective exploration of the evolution with that model. Therefore, an interactive genetic algorithm with probabilistic conditional preference networks (PCP-nets)is proposed , in which, the uncertainties are further figured out according to the interactions, and a PCP-net is designed to depict user preference model with higher accuracy by involving those uncertainties. First, the interaction time is adopted to mathematically describe the relationship between the interactions and user preference, and the reliability of the interaction time is further defined to reflect the interactive uncertainty.The preference function with evaluation uncertainty is established with the reliability of interaction time. Second, the preference weights on each interacted object are assigned on the basis of preference function and reliability. With these weights, the PCP-nets are designed and updated by involving the uncertainties into the preference model to improve the approximation. Third, a more accurate fitness function is delivered to assign fitness for the individuals. Last, the proposed algorithm is applied to a personalized book search and its superiority in exploration and feasibility is experimentally demonstrated.

Abstract: The research of the transmission capacity in wireless Ad Hoc networks based on bidirectional channels grew slowly. The closed-form expression could not be obtained. As a result, the relationship between the transmission capacity and the network parameters could not be expressed exactly. To sllve the problem, the system model of bidirectional transmission in wireless Ad Hoc networks, was proposed to redefine the bidirectional transmission capacity based on the symmetrical bidirectional transmission channel, and to derive the probability of successful transmission and tranmission capacity for bidirectional transmission. Numerical results showed that, the probability of successful transmission for single transmission was affected by some network parameters, and was mainly determined by the density of transmission pair with which the probabilityof successful transmission would increase. The bidirectional transmission capacity was mainly determined by the maxinum outage probability. When the maximum outage probability was a small value, the bidirectional transmission capacity would increase with maximum outage probability, while the quality of communicationwould reduce, so how to choose a suitable maximum outage probability was very important in real networks.

Abstract: Current service carrying network mapping algorithms ignored the business category of the service request, which resulted in the disconnection between the business carrying phase. To address this problem, a novel end-to-end service provisioning model was proposed, in which service carrying networks were constructed considering aggregating service requests belonging to the same business category and customized end-to-end services were provied via establishing the corresponding service path over the service carrying network. To evaluate the feasibility and effectiveness of the proposed model, a service carrying network mapping algorithm with hop constraint ws and desighed Layered Graph algorithm was used to select service path. Simulation experiments on a large mix of service requests showed the impact the hop constraint had on network performance in trems of cost, revenue, acceptance ratio, length of service path, etc. under different working load, validated the effectiveness of the proposed model and algorithms, and eventually determined the optimal value of hops. When the value of hops equaled 3, compared with the situation in which the value of hops equals 4 or 5, the achieved performance was approximately same, and about 50 percent and 75 percent cost of constructing service carrying vetwork can be saved respectively.

Abstract: User randomization attribute privacy protection included attribute set updating leakage and attribute leakage of key in Single-CSP(Could Service Provider), which performed mainly throygh proxy authentication, zero-knowledge proof, the trusted third party and anonymous signature. Focusing on attribute protection heavily dependent on third-party key diatribution and attribute authority, this paper presented a ciphertext policy attribute-based group signcryption randomization attribute protection scheme. When a user calculated the key factor, the scheme controled CSP getting key associated attribute information by using certificateless group signcryption connectless cross-validation; it reduced the minimal number of attribute set for signcrytion need by using attribute revocation and attribute segmentation to mutual independent with sign key and encryption key, and resisted an attacker forged signatures of attribute set updating. In key service-centric, it designed the identity verifying mechanism of group signcrypyion, and controls masquerading as other user. The scheme implemented the protection of the randomization attribute security and message privacy.

Abstract: In order to improve the robusthness and watermark capacity of digital image watermarking system, this paper presented a digital image watermarking algorithm based on fountain code and CDMA spread spectrum techniques. LT code for the purpose of encoding the original watermark was adopted, and then CDMA spread spectrum techniques was used to generate the encode watermark information. The encoded watermark information was embedded in the DCT domain of the carrier image. Blind recovery of the embedded data was achieved by using the character of cross-correlation function the orthogonal spread spectrum code. The error watermark bits would be deleted by setting decision threshold and then using the correct watermark bits to decode, which could impove the robustness of digital watermarking system. The result showed the scheme proposed in this paper coula embed larger quantities of information and raise robustuness, especially it was robust against JPEC compression, noise and cropping attacks.

Abstract: Intrusion detection algorithm based on machine learning method is one of research hotspot in the field of network equiment testing. In the face of the real-worid application requirement, machine learning methods should be further optimized to achieve accurate and stable detection effect. The study optimize steadily several key parameters of least squares support vector machine (SVM) by designing a hybird differential evolution algorithm with disturbance vector and improved the intrusion detection accuracy and stability of least squares support vector machine (SVM) algorithm by means of adaptive parameter turning. The experimental results in KDD Cup 09 test set showed that, the proposed network intrusion detedtion algorithm based on hybird dieeerential evolution algorithm had better performance on average than many similar algorithm at present.

Abstract: Cuckoo search algorithm iteratively uses Lévy Flights random walk and Biased random walk to search for new individuals. In this paper, an enhanced cuckoo search was proposed, which employed elite opposition-based learning, simplex crossover and parameter control for the fraction probablity. The elite opposition-based learning strategy was used to avoid the new individuals being homogeneous in the  Lévy Flights random walk. The simplex crossover strategy was ulilized to reduce the inefficience of Biased random walk. The chaotic map was used to adaptivrly adjust the parameter pa to balance the exploration and the exploitation. The results of experiment showed the proposed strategies were overall effective, and make a great improvement on the performance of solution and convergence.

Abstract: A method of considering tolerance principle for three dimensional tolerance analysis was put forward. Based on small displacement torsor (SDT) theory and modal interval arithmetic, the tolerance models of size tolerance and geometrical tolerance of the feature of size apply independent principle, envelope requirement, maximum material requirement, least material requirement or reciprocity requirement, were established respectively. By using the space vector to represent 3D dimension chain, a mathematical model is built to calculate the closed loop tolerance based on space vector loop stack principle. The application of the proposed method is illustrated through presenting an example, the tolerance analysis steps are given, and the availability of the proposed method was proved successfully.

Abstract: The current TOU price optimization models failed to consider the significance of reducing line loss. Through the relationship between line loss and load fluctuation, the targets of the proposed new TOU price optimization model, which was based on price elasticity matrix of demand, were to minimize peak-valley difference and line loss. The optimization model, which was a non-linear multiple objects optimal model, was solved by ideal point methed. It was proved by example that the new TOU priceoptimization model avoid the peak load and reduce the line loss.

Abstract: In CNC machinery, the industrial products and machinery parts are often represented by circular arcs. A new method for representing circular arc based on Möbius transformation was presented in the paper. By consturcting the Möbius transformation between a straight line segment and a circular curve segment, the are curve was expressed as a form of complex rational function, and a complex rational are spline function was also constructed based on the smooth constraints and the  Möbius transformation. The reprsentation had no weight factors or control parameters, and it was geometric and affin invariant. Compared with the classical method for representing circular are, such as NURBS or C-curves, the presented method was much simpler.   

Abstract: In order to meet the real-time control requirement of servo system, a dc motor control system based on FPGA was designed. The position and speed controller were realized in the Nios II, and the current loop was executed in FPGA. In order to reduce the torque ripple, an anti-windup PI controller was designed. The lead-lag controller was adopted for the position controller. The simulation and experiment result showed that the servo control system has better steady and dynamic performance, which met the requirement of the servo control system.

Abstract: This paper aims to explore fresh agricultural product E-commerce routing problem under uncertain environment. Considering the characteristic of the bounded rational of customer decision, fresh agricultural E-commerce routing optimization model was established based on Cumulative Prospect Theory (CPT). According to the characteristics of fresh agricultural E-commerce supplier for fresh features, The model took the minimum cargo damage costs, transportation costs and the penalty costs as objective, the agents point demand, goods loading and times window of logistic services about customer requirements as constraints. An improved Particle Swarm Optimization algorithm was used to solve there parts of model respectively, reference examples. Simulation and test results showed that, the model based on CPT met customer requirements on time window more accurately and improved customer satisfaction.This studycould  provide theoretical support for the fresh E-commerce suppliers to optimize the distribution path.

Abstract: In order to solve the problem that the number of selected thresholds in multilevel thresholds cannot be usually predetermined,a novel multi-level thresholding method based on Mean Shift Clustering technique was proposed.Using Mean Shift technology to explore the potential mode center,the various thresholds of ad-jacent to the mode center was automatically determined by using of iterative threshold selection method, and then the method of multi-level threshold was used for image segmentation.The experimental results showed that,relative to the original image,contrast of the image split with Mean Shift clustering technique was greatly improved.This method could control the segmentation precision flexibly by simply modifying parameters of the program,and could be widely used in the technology of single threshold segmentation, multi-level threshold segmentation and detrimental compression and other technologies.

Abstract: Warning technology of drilling engineering was the key technolog of drilling safety protection. Through the monitoring of real-time well site drilling process parameters, huge amounts of drilling data mining and intelligent learning, abnormal state modeling and optimization, abnormal state modeling and optimization, abnormal characteristics of the early warning model online judging process, achieved the goal of oil drilling abnormal state arly warning, and prevention of drilling engineering accidents. This paper reviewed the development course of early warning technology, introduced the drilling engieering warning technology architecture, and also introduced the early warning teachnology in detail and compared their characteristics, finally depicted the development of future early warning system for drilling engineering.

Abstract: To solve the MMC-HVDC dc-fault, a new sub-module topology with DC faults blocking capability is proposed, which could be used to block the fault current by its structure characteristic. On this basis, in order to restrain the adverse effects of sub-module capacitor voltage rising during the fault time, a new self-break sub-module topology with a damping resistor is proposed. The topology not only can block fault current, but also has sub-module capacitor voltage suppression effect. An 9 level SBMMC-HVDC simulation model is built in PSCAD / EMTDC platform, and the simulation proves the proposed new topology is correct.

Abstract: A kind of compaction-free lean concrete (CFLC) base was put forward in this paper. The smoothness and stability of the base could be ensured by using compaction-free lean concrete base. Meanwhile, the construction machinery and construction cycle could be reduced. Also, construction environment could be improved. Factors influence workability of CFLC were analyzed, the method and index of evaluating workability of CFLC were advanced. Orthogonality test design was adopted in tests, regression formula of evaluating index-- Vebe consistency value was educed. The results showed that the workability of CFLC could be evaluated by Vebe consistency value .

Abstract: With APTES as a modifer, the modified ATP was successfully prepared. And the adsorption of Pb(II) from aqueous solution by modified ATP was studied. The physical structure and chemical composition of raw ATP, purified ATP and modified ATP were characterized by SEM、XRD、BET、FTIR and TGA, respectively. The effects of contact time、the dosage of adsorbent、temperature and initial concentration on the adsorption property for Pb(II) were investigated through single factor static experments. The results showed that the equilibrium adsorption capacity of Pb(II) was 241.4mg•g^-1 under the following conditions:contact time 80 min、the dosage of adsorbent 0.35g•L^-1、temperature 35ºc、 ph 6 and initial concentration 100mg•L^-1.

Abstract: The phase composition, microstructure and micro-area elements analysis of Kanthal and domestic MoSi2 heating element were studied by X-ray diffraction analysis（XRD），scanning electron microscope（SEM）and energy dispersive spectrometer（EDS）. The impacr of other substancesexcept for the MoSi2 phase on the performance of typical MoSi2 heating elements was investigated. The results showed that:(1)Elemental Mo was detrimental to improving the service temperature of the MoSi2 heating element. MoO3 gas was formed by the reaction of residual Mo and oxygen at high temperture, resulting in the emergence of bubble on the surface and damage to the glass film. (2)It was necessary to increase the amount of bentonite during the production process of domestic heating element, while the amount of K, Na and other active alkali metal oxide in the bentonite was strictly controlled.(3)The MoSi2 composite powders were synthesized via alloying method of adding W in replace of traditional MoSi2 powders, which could improve the service life and operating temperature of the heating element. 

Abstract: Most important monomer dimethyldichorosilane could be prepared by disproportionating methyltrichlorosilane and chlorotrimethysilane. Disproportionation catalyzed by LiAlCl4/γ-Al2O3 were calculated at  B3LYP/6-311++G(3df,2pd) level. Activation energies of the rate-determinning step of main reaction was 15.59 kJ·mol-1. The experiment indicated the producticity that LiAlCl4/γ-Al2O3 catalyst preparing dimethyldichorosilance is 81.3%. It was higher than γ-Al2O3catalyst, and it coincided with calculated results.