Technologies of underground mobile positioning were proposed based on LiDAR data and coded sequence pattern landmarks for mine shafts and tunnels environment to meet the needs of fast and accurate positioning and navi...Technologies of underground mobile positioning were proposed based on LiDAR data and coded sequence pattern landmarks for mine shafts and tunnels environment to meet the needs of fast and accurate positioning and navigation of equipments in the mine underground without satellite navigation signals. A coded sequence pattern was employed for automatic matching of 3D scans. The methods of SIFT feature, Otsu segmentation and fast hough transformation were described for the identification, positioning and interpretation of the coded sequence patterns, respectively. The POSIT model was presented for speeding up computation of the translation and rotation parameters of LiDAR point data, so as to achieve automatic 3D mapping of mine shafts and tunnels. The moving positioning experiment was applied to evaluating the accuracy of proposed pose estimation method from LiDAR scans and coded sequence pattern landmarks acquired in an indoor environment. The performance was evaluated using ground truth data of the indoor setting so as to measure derivations with six degrees of freedom.展开更多
Design patterns are micro architectures that have proved to be reliable, robust and easy to implement. Detecting design pattern from source code of object-oriented system can help a designer, a developer or a maintain...Design patterns are micro architectures that have proved to be reliable, robust and easy to implement. Detecting design pattern from source code of object-oriented system can help a designer, a developer or a maintainer to understand the software system. In this paper, a new method is provided which can detect design patterns from source code combining both static and dynamic analysis. To acquire the run-time dynamic information of software systems, a code instrumentation method is adopted. At the same time, all static and dynamic information is presented in UML diagrams format. The pattern detection process and its detection results are visual and interactive. This method is tested on a call center and a traffic simulation system. Experimental results prove that the method is effective in design patterns detection.展开更多
Underwater acoustic communication based on Pattern Tune Delay Shift Coding （PDS） communication scheme is studied. The time delay shift values of the pattern are used to encode the digital information in the PDS sche...Underwater acoustic communication based on Pattern Tune Delay Shift Coding （PDS） communication scheme is studied. The time delay shift values of the pattern are used to encode the digital information in the PDS scheme, which belongs to the Pulse Position Modulation （PPM）. The duty cycle of the PDS scheme is small, so it can economize the power for communication. By use of different patterns for code division and different frequencies for channel division, the communication system is capable of mitigating the inter-symbol interference （ISI） caused by the muhipath channel. The data rate of communication is 1000 bits/s at 8 kHz bandwidth. The receiver separates the channels by means of bandpass filters, and performs decoding by 4 copy-correlators to estimate the time delay shift value. Based on the theoretical analysis and numerical simulations, the PDS scheme is shown to be a robust and effective approach for underwater acoustic communication.展开更多
Pattern Time Delay Shift Coding (PDS) scheme is robust for underwater acoustic communication. The digital information are encoded in the time delay shift values of the Pattern, so the PDS scheme belongs to the Pulse P...Pattern Time Delay Shift Coding (PDS) scheme is robust for underwater acoustic communication. The digital information are encoded in the time delay shift values of the Pattern, so the PDS scheme belongs to the Pulse Position Modulation (PPM). Several Patterns are selected for code division that the communication system could have a high ability to mitigate the inter-symbol interference (ISI) caused by multipath channel. Four communication channels work on the same time divided by different frequency, which lead to 1000bits/s of the data rate of communication. The simulation experiments show that the PDS system could adapt to many underwater acoustic channels for high data rate and high reliability.展开更多
This paper analyzed the problems in the existing framework, and achieved a reasonable framework based on reflection and aspect-oriented programming combined with annotations to map the request parameters, and inversio...This paper analyzed the problems in the existing framework, and achieved a reasonable framework based on reflection and aspect-oriented programming combined with annotations to map the request parameters, and inversion of the control of the various components. The proposed framework reduced the volume of the application context, and achieved the purpose that dependencies between the various components are controlled by the framework. Based on the problems existing in the known framework, the lightweight MVC framework was implemented and the proposed framework was tested by JMeter test tool. The test results showed that the framework proposed in this paper can respond to requests faster, improve access throughput and enhance application performance and user experience. The framework proposed in this paper combined the functions of MVC and IOC to minimize the volume of external dependencies in the development and greatly improved the efficiency of Web applications development.展开更多
Discusses block truncation coding (BTC) a simple and fast image compression technique suitable for real time image transmission with high channel error resisting capability and good reconstructed image quality, and it...Discusses block truncation coding (BTC) a simple and fast image compression technique suitable for real time image transmission with high channel error resisting capability and good reconstructed image quality, and its main drawback of high bit rate of 2 bits/pixel for a 256 gray image for the purpose of reducing the bit rate, and introduces a simple look up table method for coding the higher mean and the lower mean of a block, and a set of 24 visual patterns used to encode 4×4 bit plane of the high detail block and proposes a new algorithm, when needs only 19 bits to encode 4×4 high detail block and 12 bits to encode the 4×4 low detail block.展开更多
Pattern时延差(PDS:Pattern time Delay Shift)编码通信体制具有很好的抗多途干扰能力,但传输过程中仍存在一定的误码。为提高该体制的抗噪声能力,将网格编码调制(TCM:Trellis-Coded Modulation)技术与PDS体制结合使用,对信息进行网格...Pattern时延差(PDS:Pattern time Delay Shift)编码通信体制具有很好的抗多途干扰能力,但传输过程中仍存在一定的误码。为提高该体制的抗噪声能力,将网格编码调制(TCM:Trellis-Coded Modulation)技术与PDS体制结合使用,对信息进行网格编码调制和维特比软判决译码。实验结果证明,该方案抗噪声效果显著,可使PDS体制的抗噪声性能提高3 dB左右。展开更多
研究了Pattern时延差编码(Pattern Time Delay Shift Coding,PTDS)水声通信的差分解码技术。在移动水声通信中,多普勒频偏会对信号产生时间上的压缩或展宽。差分解码通过测量相邻Pattern的时间差进行时延估计完成译码,克服了多普勒频偏...研究了Pattern时延差编码(Pattern Time Delay Shift Coding,PTDS)水声通信的差分解码技术。在移动水声通信中,多普勒频偏会对信号产生时间上的压缩或展宽。差分解码通过测量相邻Pattern的时间差进行时延估计完成译码,克服了多普勒频偏在时间上的累加效应,具有更强的抵抗多普勒能力,为移动水声通信技术的研究打下了基础。仿真实验证明所提出的解码方案简单易行、性能优良。展开更多
High-repetition-rate femtosecond lasers enable the precise production of nanofoam from a wide range of materials. Here, the laser-based fabrication of nanofoam from silicon, borosilicate glass, sodalime glass, gallium...High-repetition-rate femtosecond lasers enable the precise production of nanofoam from a wide range of materials. Here, the laser-based fabrication of nanofoam from silicon, borosilicate glass, sodalime glass, gallium lanthanum sulphide and lithium niobate is demonstrated, where the pore size of the nanofoam is shown to depend strongly on the material used, such that the pore width and nanofibre width appear to increase with density and thermal expansion coefficient of the material. In addition, the patterning of nanofoam on a glass slide, with fabricated pattern pixel resolution of ~35 μm, is demonstrated.展开更多
A novel coding based method named as local binary orientation code （LBOCode） for palmprint recognition is proposed. The palmprint image is firstly convolved with a bank of Gabor filters, and then the orientation inf...A novel coding based method named as local binary orientation code （LBOCode） for palmprint recognition is proposed. The palmprint image is firstly convolved with a bank of Gabor filters, and then the orientation information is attained with a winner-take-all rule. Subsequently, the resulting orientation mapping array is operated by uniform local binary pattern. Accordingly, LBOCode image is achieved which contains palmprint orientation information in pixel level. Further we divide the LBOCode image into several equal-size and nonoverlapping regions, and extract the statistical code histogram from each region independently, which builds a global description of palmprint in regional level. In matching stage, the matching score between two palmprints is achieved by calculating the two spatial enhanced histograms＇ dissimilarity, which brings the benefit of computational simplicity. Experimental results demonstrate that the proposed method achieves more promising recognition performance compared with that of several state-of-the-art methods.展开更多
基金Project(2011CB707102)supported by the National Basic Research Program of ChinaProjects(40901220,41001302)supported by the National Natural Science Foundation of China+1 种基金Project(122025)supported by Fok Ying Tong Education Foundation,ChinaProject(N100401009)supported by Fundamental Research Funds for Central Universities,China
文摘Technologies of underground mobile positioning were proposed based on LiDAR data and coded sequence pattern landmarks for mine shafts and tunnels environment to meet the needs of fast and accurate positioning and navigation of equipments in the mine underground without satellite navigation signals. A coded sequence pattern was employed for automatic matching of 3D scans. The methods of SIFT feature, Otsu segmentation and fast hough transformation were described for the identification, positioning and interpretation of the coded sequence patterns, respectively. The POSIT model was presented for speeding up computation of the translation and rotation parameters of LiDAR point data, so as to achieve automatic 3D mapping of mine shafts and tunnels. The moving positioning experiment was applied to evaluating the accuracy of proposed pose estimation method from LiDAR scans and coded sequence pattern landmarks acquired in an indoor environment. The performance was evaluated using ground truth data of the indoor setting so as to measure derivations with six degrees of freedom.
基金Project supported by the National Natural Science Foundation of China（Grant No.60473063）
文摘Design patterns are micro architectures that have proved to be reliable, robust and easy to implement. Detecting design pattern from source code of object-oriented system can help a designer, a developer or a maintainer to understand the software system. In this paper, a new method is provided which can detect design patterns from source code combining both static and dynamic analysis. To acquire the run-time dynamic information of software systems, a code instrumentation method is adopted. At the same time, all static and dynamic information is presented in UML diagrams format. The pattern detection process and its detection results are visual and interactive. This method is tested on a call center and a traffic simulation system. Experimental results prove that the method is effective in design patterns detection.
文摘Underwater acoustic communication based on Pattern Tune Delay Shift Coding （PDS） communication scheme is studied. The time delay shift values of the pattern are used to encode the digital information in the PDS scheme, which belongs to the Pulse Position Modulation （PPM）. The duty cycle of the PDS scheme is small, so it can economize the power for communication. By use of different patterns for code division and different frequencies for channel division, the communication system is capable of mitigating the inter-symbol interference （ISI） caused by the muhipath channel. The data rate of communication is 1000 bits/s at 8 kHz bandwidth. The receiver separates the channels by means of bandpass filters, and performs decoding by 4 copy-correlators to estimate the time delay shift value. Based on the theoretical analysis and numerical simulations, the PDS scheme is shown to be a robust and effective approach for underwater acoustic communication.
文摘Pattern Time Delay Shift Coding (PDS) scheme is robust for underwater acoustic communication. The digital information are encoded in the time delay shift values of the Pattern, so the PDS scheme belongs to the Pulse Position Modulation (PPM). Several Patterns are selected for code division that the communication system could have a high ability to mitigate the inter-symbol interference (ISI) caused by multipath channel. Four communication channels work on the same time divided by different frequency, which lead to 1000bits/s of the data rate of communication. The simulation experiments show that the PDS system could adapt to many underwater acoustic channels for high data rate and high reliability.
文摘This paper analyzed the problems in the existing framework, and achieved a reasonable framework based on reflection and aspect-oriented programming combined with annotations to map the request parameters, and inversion of the control of the various components. The proposed framework reduced the volume of the application context, and achieved the purpose that dependencies between the various components are controlled by the framework. Based on the problems existing in the known framework, the lightweight MVC framework was implemented and the proposed framework was tested by JMeter test tool. The test results showed that the framework proposed in this paper can respond to requests faster, improve access throughput and enhance application performance and user experience. The framework proposed in this paper combined the functions of MVC and IOC to minimize the volume of external dependencies in the development and greatly improved the efficiency of Web applications development.
文摘Discusses block truncation coding (BTC) a simple and fast image compression technique suitable for real time image transmission with high channel error resisting capability and good reconstructed image quality, and its main drawback of high bit rate of 2 bits/pixel for a 256 gray image for the purpose of reducing the bit rate, and introduces a simple look up table method for coding the higher mean and the lower mean of a block, and a set of 24 visual patterns used to encode 4×4 bit plane of the high detail block and proposes a new algorithm, when needs only 19 bits to encode 4×4 high detail block and 12 bits to encode the 4×4 low detail block.
文摘研究了Pattern时延差编码(Pattern Time Delay Shift Coding,PTDS)水声通信的差分解码技术。在移动水声通信中,多普勒频偏会对信号产生时间上的压缩或展宽。差分解码通过测量相邻Pattern的时间差进行时延估计完成译码,克服了多普勒频偏在时间上的累加效应,具有更强的抵抗多普勒能力,为移动水声通信技术的研究打下了基础。仿真实验证明所提出的解码方案简单易行、性能优良。
文摘High-repetition-rate femtosecond lasers enable the precise production of nanofoam from a wide range of materials. Here, the laser-based fabrication of nanofoam from silicon, borosilicate glass, sodalime glass, gallium lanthanum sulphide and lithium niobate is demonstrated, where the pore size of the nanofoam is shown to depend strongly on the material used, such that the pore width and nanofibre width appear to increase with density and thermal expansion coefficient of the material. In addition, the patterning of nanofoam on a glass slide, with fabricated pattern pixel resolution of ~35 μm, is demonstrated.
基金supported partly by the National Grand Fundamental Research 973 Program of China under Grant No. 2004CB318005the Doctoral Candidate Outstanding Innovation Foundation under Grant No.141092522the Fundamental Research Funds under Grant No.2009YJS025
文摘A novel coding based method named as local binary orientation code （LBOCode） for palmprint recognition is proposed. The palmprint image is firstly convolved with a bank of Gabor filters, and then the orientation information is attained with a winner-take-all rule. Subsequently, the resulting orientation mapping array is operated by uniform local binary pattern. Accordingly, LBOCode image is achieved which contains palmprint orientation information in pixel level. Further we divide the LBOCode image into several equal-size and nonoverlapping regions, and extract the statistical code histogram from each region independently, which builds a global description of palmprint in regional level. In matching stage, the matching score between two palmprints is achieved by calculating the two spatial enhanced histograms＇ dissimilarity, which brings the benefit of computational simplicity. Experimental results demonstrate that the proposed method achieves more promising recognition performance compared with that of several state-of-the-art methods.
