共查询到20条相似文献，搜索用时 15 毫秒
1.
In this paper we discuss a novel storage scheme for simultaneous memory access in parallel turbo decoder. The new scheme employs vertex coloring in graph theory. Compared to a similar method that also uses unnatural order in storage, our scheme requires 25 more memory blocks but allows a simpler configuration for variable sizes of code lengths that can be implemented on-chip. Experiment shows that for a moderate to high decoding throughput （40-100 Mbps）, the hardware cost is still affordable for 3GPP＇s （3rd generation partnership project） interleaver. 相似文献
2.
A novel asymmetrical pitch system for rotary wing is presented. The pitch control characteristics are studied and analyzed.
Because elastic linkage is a key part in whole asymmetrical pitch system, in order to obtain the variation of the elastic
linkage deformation, an experimental platform mainly based on the device of micro aerial vehicles (MAVs) and a new control
system mounted on TMS320LF2407 are designed. This control system has its compacted configuration and reliability. Finally,
using this system to control the MAV for simulating the flying forward, experimental results show the MAV’s flight attitude
can be controlled based on the variation of the elastic linkage.
Project supported by the National Natural Science Foundation of China (Grant No.60605028), the National High-Technology Research
and Development Program of China (Grant No.2007AA04Z225), the Shanghai Rising-Star Program (Grant Nos.07QA14024, 07QH14006),
the Shanghai Shuguang Program (Grant No.07SG47), and the Shanghai Leading Key Laboratory of Mechanical Automation and Robotics
Science Foundation (Grant No.ZZ0805) 相似文献
3.
Cluster parallel rendering based on encoded mesh 总被引：2，自引：0，他引：2
QIN Ai-hong XIONG Hua PENG Hao-yu LIU Zhen SHI Jiao-ying 《浙江大学学报(A卷英文版)》2006,7(7):1124-1133
INTRODUCTION Three dimensional (3D) meshes are widely used to represent 3D objects. With the rapid advances in digital acquisition technology, meshes with millions of vertices are becoming increasingly common. Be- cause of memory constraints and lack of graphics power, visualizations of this magnitude are difficult or impossible to perform even on the most powerful workstations. Therefore, the need for parallel im- plementation is clear. Most previous work in high performance rendering h… 相似文献
4.
File semantic has proven effective in optimizing large scale distributed file system. As a consequence of the elaborate and
rich I/O interfaces between upper layer applications and file systems, file system can provide useful and insightful information
about semantic. Hence, file semantic mining has become an increasingly important practice in both engineering and research
community. Unfortunately, it is a challenge to exploit file semantic knowledge because a variety of factors could affect this
information exploration process. Even worse, the challenges are exacerbated due to the intricate interdependency between these
factors, and make it difficult to fully exploit the potentially important correlation among various semantic knowledges. This
article proposes a file access correlation miming and evaluation reference (FARMER) model, where file is treated as a multivariate
vector space, and each item within the vector corresponds a separate factor of the given file. The selection of factor depends
on the application, examples of factors are file path, creator and executing program. If one particular factor occurs in both
files, its value is non-zero. It is clear that the extent of inter-file relationships can be measured based on the likeness
of their factor values in the semantic vectors. Benefit from this model, FARMER represents files as structured vectors of
identifiers, and basic vector operations can be leveraged to quantify file correlation between two file vectors. FARMER model
leverages linear regression model to estimate the strength of the relationship between file correlation and a set of influencing
factors so that the “bad knowledge” can be filtered out. To demonstrate the ability of new FARMER model, FARMER is incorporated
into a real large-scale object-based storage system as a case study to dynamically infer file correlations. In addition FARMER-enabled
optimize service for metadata prefetching algorithm and object data layout algorithm is implemented. Experimental results
show that is FARMER-enabled prefetching algorithm is shown to reduce the metadata operations latency by approximately 30%–40%
when compared to a state-of-the-art metadata prefetching algorithm and a commonly used replacement policy. 相似文献
5.
6.
Ensemble learning HMM for motion recognition and retrieval by Isomap dimension reduction 总被引：1，自引：0，他引：1
XIANG Jian WENG Jian-guang ZHUANG Yue-ting WU Fei 《浙江大学学报(A卷英文版)》2006,7(12):2063-2072
INTRODUCTION Now more and more motion capture systems are used to acquire realistic human motion data. Due to the success of the Mocap systems, realistic and highly detailed motion clips are commercially available and widely used for producing animations of human-like characters in a variety of applications, such as simu- lations, video games and animation files. Therefore an efficient motion data recognition and retrieval technique is needed to support motion data processing, such as mot… 相似文献
7.
LENG Biao QIN Zheng LI Li-qun 《浙江大学学报(A卷英文版)》2007,8(12):1953-1961
In this paper, we present a novel Support Vector Machine active learning algorithm for effective 3D model retrieval using the concept of relevance feedback. The proposed method learns from the most informative objects which are marked by the user, and then creates a boundary separating the relevant models from irrelevant ones. What it needs is only a small number of 3D models labelled by the user. It can grasp the user's semantic knowledge rapidly and accurately. Experimental results showed that the proposed algorithm significantly improves the retrieval effectiveness. Compared with four state-of-the-art query refinement schemes for 3D model retrieval, it provides superior retrieval performance after no more than two rounds of relevance 相似文献
8.
LIU Bao-you FANG You-tong WEI Jin-xiang WANG Yong-liang 《浙江大学学报(A卷英文版)》2007,8(3):495-500
In general, every system is in one of the three states: normal, abnormal, or failure state. When the system is diagnosed as abnormal state, it needs predictive maintenance. If the system fails, an identical new one will replace it. The predictive main- tenance cannot make the system “as good as new”. Under these assumptions, the reliability index and the inspection-replacement policy of a system were studied. The explicit expression of the reliability index and the average income rate (i.e., the long-run average income per unit time) are derived by using probability analysis and vector Markov process method. The criterion of feasibility for the optimal inspection-replacement policy under the maximum average income rate is obtained. The numerical example shows the optimal inspection-replacement policy can raise the average income rate when the optimal inspec- tion-replacement policy is feasible. 相似文献
9.
GUO Hui WANG Yun-peng WANG Zhi-guang ZHOU Jing-li 《浙江大学学报(A卷英文版)》2006,7(6):1001-1007
INTRODUCTION Because of the critical role that computing sys-tems and networks play in today’s business envi-ronment, it is not surprising that business success often goes to the company with the best information and the most efficient process for delivering that in-formation. As the principal tool for business col-laboration, corporate LANs are a vital resource in enabling today’s enterprises to adopt competitive strategies. The number of users wanting to share and access data across… 相似文献
10.
Kinetic knowledge is of great importance in achieving good control of the pyrolysis and gasification process and optimising
system design. An overall kinetic pyrolysis scheme is therefore addressed here. The kinetic modelling incorporates the following
basic steps: the degradation of the virgin biomass materials into primary products (tar, gas and semi-char), the decomposition
of primary tar into secondary products and the continuous interaction between primary gas and char. The last step is disregarded
completely by models in the literature. Analysis and comparison of predicted results from different kinetic schemes and experimental
data on our fixed bed pyrolyser yielded very positive evidence to support our kinetic scheme.
Project (No. 2001CB409600) Supported by the National Key Basic Research Program (973) of China 相似文献
11.
海量存储系统中高扩展性元数据分布算法的研究 总被引：2，自引：2，他引：0
Distribution of metadata in a metadata server cluster is important in mass storage system. A good distribution algorithm has a significant influence on the system performance, availability and scalability. Subtree partition and hash are two traditional metadata distribution algorithms used in distributed file systems. They both have a defect in system scalability. This paper proposes a new directory hash （DH） algorithm. By treating directory as the key value of hash function, implementing concentrated storage of metadata, pipelining operations and prefetching technology, DH algorithm can enhance the system scalability on the premise without sacrificing system performance. 相似文献
12.
This paper studies the security of an image encryption scheme based on the Hill cipher （Ismail et al., 2006） and reports its following problems： （1） There is a simple necessary and sufficient condition that makes a number of secret keys invalid; （2） It is insensitive to the change of the secret key; （3） It is insensitive to the change of the plain-image; （4） It can be broken with only one known/chosen plaintext; （5） It has some other minor defects. The proposed cryptanalysis discourages any use of the scheme in practice. 相似文献
13.
Recently there has been an increasing interest in applying random walk based methods to recommender systems. We employ a Gaussian random field to model the top-N recommendation task as a semi-supervised learning problem, taking into account the degree of each node on the user-item bipartite graph, and induce an effective absorbing random walk （ARW） algorithm for the top-N recommendation task. Our random walk approach directly generates the top-N recommendations for individuals, rather than predicting the ratings of the recommendations. Experimental results on the two real data sets show that our random walk algorithm significantly outperforms the state-of-the-art random walk based personalized ranking algorithm as well as the popular item-based collaborative filtering method. 相似文献
14.
The main thrust of this paper is application of a novel data mining approach on the log of user's feedback to improve web
multimedia information retrieval performance. A user space model was constructed based on data mining, and then integrated
into the original information space model to improve the accuracy of the new information space model. It can remove clutter
and irrelevant text information and help to eliminate mismatch between the page author's expression and the user's understanding
and expectation. User space model was also utilized to discover the relationship between high-level and low-level features
for assigning weight. The authors proposed improved Bayesian algorithm for data mining. Experiment proved that the authors'
proposed algorithm was efficient.
Project (No. 20020335020) supported by Research Fund for Doctoral Program, Ministry of Education of China 相似文献
15.
INTRODUCTION High data rate and high quality multimedia ser- vices are required in beyond third generation (B3G) and fourth generation (4G) mobile communications. Space-time coding scheme has been proposed (Tarokh et al., 1998; 1999) to achieve higher capacity and data rate. So far, most research on space-time coding assumed that accurate channel estimations are available at the receivers. However, accurate channel estimation is difficult and too many training symbols are required in a r… 相似文献
16.
There are many cases when an organization needs to monitor the data and operations of its supervised departments, especially
those departments which are not owned by this organization and are managed by their own information systems. Distributed Heterogeneous
Inspecting System (DHIS) is the system an organization uses to monitor its supervised departments by inspecting their information
systems. In DHIS, the inspected systems are generally distributed, heterogeneous, and constructed by different companies.
DHIS has three key processes-abstracting core data sets and core operation sets, collecting these sets, and inspecting these
collected sets. In this paper, we present the concept and mathematical definition of DHIS, a metadata method for solving the
interoperability, a security strategy for data transferring, and a middleware-based solution of DHIS. We also describe an
example of the inspecting system at WENZHOU custom.
Project supported by the National Hi-Tech Development Program (863) of China (No. 2001AA111271-2) and virtual cooperation
research granted by Chinese Ministry of Education 相似文献
17.
Stabilization for a class of second-order switched systems with saturation constrains 总被引：1，自引：0，他引：1
This paper proposes a global stabilization method for a class of planar switched systems with input saturation constrains
by using a state feedback and switching strategy. This method is proved to be effective by analyzing the characteristics of
the trajectory of second-order linear systems with input saturation.
Project supported by the China Postdoctoral Science Foundation (Grant No.20070420643), the National Natural Science Foundation
of China (Grant No.60774059), and the Innovation Program of the Shanghai Municipal Science and Technology Commission (Grant
No.08DZ2272400) 相似文献
18.
Absorption of NO2 into Na2S solution in a stirred tank reactor 总被引：1，自引：1，他引：0
To understand the absorption mechanism of nitrogen dioxide into a sodium sulfide solution, a stirred tank reactor with a plane gas-liquid interface was used to measure the chemical absorption rate of diluted nitrogen dioxide into sodium sulfide solution. The absorption rates under various experimental conditions were measured and the effects of experimental conditions on nitrogen dioxide absorption rate were discussed. The results show that, in the range of this study, nitrogen dioxide absorption rate increases with increasing sodium sulfide concentration, nitrogen dioxide inlet concentration, and flue gas flow rate, but decreases with increasing reaction temperature and oxygen content in flue gas. 相似文献
19.
Texture classification based on EMD and FFT 总被引：2，自引：0，他引：2
XIONG Chang-zhen XU Jun-yi ZOU Jian-cheng QI Dong-xu 《浙江大学学报(A卷英文版)》2006,7(9):1516-1521
INTRODUCTION Multi-scale is one of the main features of natural images, a series of methods for representing the quality of images are presented, such as multi-scale technique based on diffusion equation (Perona and Malik, 1990), image pyramid (Burt and Adelson, 1983) and wavelet (Mallat, 1989). Bidimensional empirical mode decomposition (BEMD) (Nunes et al., 2005; Linderhed, 2004) is a new multi-scale analysis method proposed recently. The difference between BEMD and traditional mul… 相似文献
20.
By using some elementary inequalities, authors in this paper makes further improvement for estimating the heights of Bézier
curve and rational Bézier curve. And the termination criterion for subdivision of the rational Bézier curve is also improved.
The conclusion of the extreme value problem is thus further confirmed.
Project supported by the National Natural Science Foundation of China (No. 60173034) and the Foundation of State Key Basic
Research(973) Program (No. G1998030600), China 相似文献