2016 volumne 37卷 Issue 03
MU Xiaomin , SHI Guangqiang,LIU Ying , YANG Shouyi
Abstract: To solve the problem of contract-based cooperative spectrum sharing between multiple primary usersand multiple secondary users,we put forward a contract design method based on statistical theory to maximizethe total utility of primary users. Firstly,the primary users make full use of the accepting contract statisticalinformation of secondary users to design a reasonable contract. Then,the primary users according to the statis-tical expected utility to obtain the optimization problem of maximizing theirs total expected utilities. Further-more,we simplify the problem in theory and exploit the genetic algorithm to derive the sub-optimal solution.The simulation results and analysis show the contract design method can solve the problem of contract-basedcooperative spectrum sharing successfully.Compared with the DMA-UI,the approach we formulated can makeprimary users obtain a higher utility, and further improve the primary users’energy efficiency and spectrumefficiency.
CHEN Xiaopan1 ,QU Jiantao1,2,ZHAO Yameng2, WANG Peng1, 2 , CHEN Yulin1
Abstract: When dealing with massive terrain data ,the advantage of hardware performance can’t be fully uti-lized. This has become a bottleneck,which restricts the speed of massive terrain tiles rendering. This paperanalyzes the key factors that affect large-scale terrain rendering speed,and proposes a parallel algorithm formassive terrain data processing. The algorithm adopts double buffer queues and divides large scale terrain ren-dering into two parallel processing which includes data processing and rendering. The two buffer queues areresponsible for data reading and writing operations in turn. The loading priority of terrain tiles is consideredand tasks are allocated based on the priority. The experimental results show that this approach improves thespeed of rendering massive terrain tiles greatly.
Shuxin Chen, Lingyu Zhang,
Abstract: There are many semantic interoperability problems between different ontologies, such as: semantic conflicts and structural heterogeneity, which seriously affect the knowledge sharing and reuse between ontologies; and also bring great difficulties to the ontology query service, for this reason, a WordNet-based ontology query framework OQ-WordNet is proposed. The framework first uses WordNet, a semantic lexicon library, to accurately compute the similarity of concepts between different ontologies (source ontologies); then generates a target ontology for all source ontologies by ontology integration and ontology mapping methods, and establishes the semantic mapping relationship between them; finally, OQ-WordNet uses SPARQL, an ontology query language, to implement the query function between ontologies.
Zhang Hongmei, Wen Hueran, Zhang Xiangli, Li Pengfei
Li Huiping, Yu Xiuli, Gao Pengjie, Mao Zhendong
Abstract: In order to investigate the relationship between proton conduction rate and intermolecular hydrogen bond strength of tetrazole system, the geometric structure optimization and frequency analysis of tetrazole dimer N4 CH2-N4CH3 at the level of B3 LYP/6-311++ G(2d,2p) were carried out by using density flooding theory, focusing on the structure, energy, natural bond orbital (NBO) and The QST2 method was used to study the dynamic processes of proton transfer in the eight dimer interrogations at the B3LYP/6-31+ G(d) level, and six filtered states were found and their transfer energy barriers were calculated. The results showed that tetrazole and protonated tetrazole cations formed the dimer N4CH2-N4CH3 with strong intermolecular interactions through N...H-N hydrogen bonding, and the N...H-N hydrogen bonding exhibited obvious red-shift characteristics; N ...H-N hydrogen bonding interaction stabilization energy is mainly the interaction between the lone pair electron orbital of N atom and the anti-bonding orbital of N-H bond; N...H-N hydrogen bonding strength is the main factor affecting the size of proton transfer energy barrier, i.e. directly affects the proton conduction rate in the tetrazolium system.
LIU Zhenghua1, WANG Jing2,DU Haiying’1,2
Abstract: In order to solve the problem that electrospinning process is hard to control,FEA tool softwareCOMSOL Multiphysics was used to simulate the the electric field orientation within the electrospinning. Basedon the vector maps and contour lines, the electric fields distribution was analyzed. Which includes single-nee-dle electrospinning device,electrospinning device with circle and orparallel auxiliary electrodes. Experimentwith parallel auxiliary electrodes was conducted,and the deposition area with the ellipse shape matched thesimulation result.
Wang Ruoping, Huang Jie
Abstract: In the subjective evaluation of the NVH performance of a car model, it was found that after the suspension adjustment, the steering wheel vibration was still too large under the idle air conditioner condition, which affected the comfort of the whole car. Lab equipment was used to test the steering wheel vibration at idle speed, and the preliminary judgment was that the cooling fan fundamental frequency had a greater influence on the steering wheel shaking. Using the experimental modal analysis theory and method to analyze the excitation source, main transmission path and response point respectively, it was found that the cooling module (CRFM) and steering wheel modal parameters of the car were consistent with the cooling fan fundamental frequency. The test results show that the steering wheel shake can be significantly reduced by improving the structure of the damping pad and adjusting the cooling fan speed in combination with the actual situation of the vehicle.
Chunlan Zhang1, Lu Mai2, Xiaoqiang Chen1, Kongbing Wei3
Abstract: In order to further improve the stimulation focus of the circular coil, a circular coil with deformation along different positions was designed. The spatial magnetic field distribution of the deformed circular coil was analyzed by numerical simulation at the folding position and folding angle. Compared with the conventional circular coil, the magnetic field focus of the deformed circular coil folded unilaterally at 0.5, 1 and 1.5 cm from the center of the circle was significantly improved, and the optimal folding angles were 60°~90°, 60°~105° and 75°~105°, respectively. The spatial magnetic field focus was improved by folding the deformed circular coil at 2 cm from the center of the garden on one side and at 2 cm from the center of the garden on both sides.
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