The 30CrMnSiNi2 A steel has been commonly used in the national defense industry and engineering *** fracture properties of the material are studied by dynamic tensile tests on a traditional Hopkinson system and three-...
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The 30CrMnSiNi2 A steel has been commonly used in the national defense industry and engineering *** fracture properties of the material are studied by dynamic tensile tests on a traditional Hopkinson system and three-point bend tests on a modified Hopkinson loading *** dynamic tensile experiments results show that 30CrMnSiNi2 A steel is sensitive of the strain *** dynamic fracture toughness of the material increases with the rise of loading rate,but its value is less than the static fracture toughness *** over,the fracture mechanism is investigated through macroscopic and microstructural analysis,which reveals that the fracture mechanism of30CrMnSiNi2 A belongs to quasi-cleavage fracture.
With the rapid increase of websites and internet users,the traditional search engine will face great challenge in the real-time search,response speed and mass storage *** cloud computing with two major advantages in m...
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With the rapid increase of websites and internet users,the traditional search engine will face great challenge in the real-time search,response speed and mass storage *** cloud computing with two major advantages in massive data processing and mass data storage,so the search engine deployed in the cloud can solve these *** analyzing the open-source cloud computing system Hadoop,cloud platform search engine model is constructed and search engine algorithm is optimized to improve the overall performance of search engines.
The Croatian Scientific Bibliography -CROSBI is a bibliography web site that stores information about scientific papers published in Croatia in the last 15 years. At the present, CROSBI consists of over 400,000 record...
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ISBN:
(纸本)9789532330816
The Croatian Scientific Bibliography -CROSBI is a bibliography web site that stores information about scientific papers published in Croatia in the last 15 years. At the present, CROSBI consists of over 400,000 records and is daily accessed and updated by a large number of researchers. As the appearance and purpose of database (and hence its structure) changed over the years, some inconsistencies emerged, and existing data could not be used to its fullest potential, e.g. linking papers from the same journal or conference, or analysis of scientific activity in relation to the place of article publication. This paper explores the possibilities of improving and enriching the CROSBI database, using different techniques, from data cleaning and sanity checking, to creating links between CROSBI and similar online bibliographic databases. In order to improve data quality, book records from CROSBI were linked to the corresponding Google Books records, and using Semantic Web technologies, a number of links between CROSBI and online bibliographic databases was created. The resulting data set can be used to further improve the quality of CROSBI by creating a recommender system, or to improve and open up new possibilities in the analysis of existing data.
It is often difficult for students and teachers to ask or answer questions to describe their situations clearly, especially for questions in science and engineering fields. This paper comes up with a mobile multimedia...
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It is often difficult for students and teachers to ask or answer questions to describe their situations clearly, especially for questions in science and engineering fields. This paper comes up with a mobile multimedia Q & A system based on Android client, which enables students to describe their questions more clearly and makes teachers' answers more intuitive. What's more, other students can also participate in the process of Q & A. And more importantly, questions including corresponding answers of high quality can be stored for students to reuse in the future.
There are lots of distributed sources in the process of fatigue crack propagation of the lattice boom,static evaluation of the reliability indicators cannot be satisfied to solve practical engineering *** load and fat...
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There are lots of distributed sources in the process of fatigue crack propagation of the lattice boom,static evaluation of the reliability indicators cannot be satisfied to solve practical engineering *** load and fatigue resistance regards as a random process,considers the fatigue failure of the randomness in a variety of factors,the concept of dynamic reliability of the weights index is proposed,models of dynamic reliability of the weights index are built based on the fatigue bearing capacity mode and limit damage degree *** stress experiments comparisons are doing during a crawler crane according to the actual operating conditions and a K-type welded joints *** results show that the dynamic reliability evaluation assessment model is more accurately in the fatigue life evaluation and the method can provide a new assessment method for engineering applications.
In order to realize high speed and real-time video monitoring,a hardware development platform based on FPGA was *** CMOS image sensor OV7620 to collect video information,the data was real-time processed and stored by ...
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In order to realize high speed and real-time video monitoring,a hardware development platform based on FPGA was *** CMOS image sensor OV7620 to collect video information,the data was real-time processed and stored by EP1C12Q24C8 of Cyclone series.A 400×240 resolution LCD display the *** paper settled the SCCB communication and implemented the software driver for OV7620 and *** FIFO "ping-pong operation" were used as data buffer for clock domain conversion to solve the inconsistencies rates problem when various components read and wrote *** size of video display area can be changed by control signal which greatly improves the performance of the system for accuracy,real-time and *** experiment results show that the system can clearly display the video surveillance information and is suitable for industrial video information surveillance areas that have rigorous demanding for real-time,power and volume.
Content-based antique coin image retrieval is a hot issue for modern digital museumIn the paper, we proposed an image retrieval method using histogram of centroid distance as a coarse feature descriptor and modified m...
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Content-based antique coin image retrieval is a hot issue for modern digital museumIn the paper, we proposed an image retrieval method using histogram of centroid distance as a coarse feature descriptor and modified moment invariants as a fine feature descriptorAccordingly, an antique coin image retrieval system is designed for Chinese antique coin image databaseThe approach is implemented by simulation and the retrieval results are obtained with promising performanceThe experimental results demonstrate that the method can improve the quality of retrieval and is valuable for the construction of digital museum.
In this paper an adaptive Contourlet-domain watermarking algorithm is proposed based on chaotic encryption. In order to enhance the security of watermarking, the watermark is processed using chaotic encryption. The wa...
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In this paper an adaptive Contourlet-domain watermarking algorithm is proposed based on chaotic encryption. In order to enhance the security of watermarking, the watermark is processed using chaotic encryption. The wavelet-based Contourlet transform is applied on the host image. When being embedded, the encrypted watermark is adaptively embedded into the Contourlet coefficients with larger magnitude that correspond to the edges. And then, the algorithm automatically adjusts the intensity of embedding. Furthermore a blind detection method is presented using Neyman-Pearson criterion. The experimental results prove the validity of this proposed algorithm and good robustness against several common watermarking attacks.
In Hard disk drive(HDD) industry,the demand for faster HDD with higher storage capacities had led to the use of a dual-stage servo system with a high precision PZT ***,the PZT actuator is made of piezoelectric materia...
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In Hard disk drive(HDD) industry,the demand for faster HDD with higher storage capacities had led to the use of a dual-stage servo system with a high precision PZT ***,the PZT actuator is made of piezoelectric material which exhibits *** causes inaccuracies and oscillations in the system *** this paper,the hysteresis behavior is examined for a new high resolution(a few nanometers) PZT actuator fabricated for dual stage *** new PZT actuator has the first resonance at a frequency twenty times higher than the first resonant mode of PZT actuator used at present in HDD.A generalized Prandtl-Ishlinskii(GPI)model is obtained by using curve-fitting with the examined hysteresis *** the inverse of the GPI model is extracted which can be used as the hysteresis *** a model-free hysteresis compensator using adaptive Neural Network algorithm is being proposed for future research.
Aiming at the problem of constructing huge amounts of projected databases in Prefix Span algorithm,this paper proposes an Improved Prefix Span algorithm for Mining Sequential Patterns,called BLSPM algorithm（based on ...
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Aiming at the problem of constructing huge amounts of projected databases in Prefix Span algorithm,this paper proposes an Improved Prefix Span algorithm for Mining Sequential Patterns,called BLSPM algorithm（based on bi-level Sequential Patterns Mining）.The algorithm use duplicated projection and certain specific sequential patterns pruning,reduce the scale of projected databases and the runtime of scanning projected databases,thus,the efficiency of algorithm could be raised up greatly,and all needed sequential patterns are *** results shows that BLSPM algorithm is more efficient than Prefix Span algorithm in large databases.
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