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Modelling of modern automotive petrol engine performance using Support Vector Machines
VONG Chi-man, WONG Pak-kin, LI Yi-ping, HO Chon-meng
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2005, 6(1): 1-.   https://doi.org/10.1631/jzus.2005.A0001
Abstract( 2844 )     PDF(0KB)( 1608 )
Modern automotive petrol engine performance is significantly affected by effective tune-up. Current practice of engine tune-up relies on the experience of the automotive engineer, and tune-up is usually done by trial-and-error method and then the vehicle
The construction and combined operation for fuzzy consistent matrixes
YAO Min, SHEN Bin, LUO Jian-hua
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2005, 6(1): 4-.   https://doi.org/10.1631/jzus.2005.A0027
Abstract( 2605 )     PDF(0KB)( 998 )
Fuzziness is one of the general characteristics of human thinking and objective things. Introducing fuzzy techniques into decision-making yields very good results. Fuzzy consistent matrix has many excellent characteristics, especially center-division transitivity conforming to the reality of the human thinking process in decision-making. This paper presents a new approach for creating fuzzy consistent matrix from mutual supplementary matrix in fuzzy decision-making. At the same time, based on the distance between individual fuzzy consistent matrix and average fuzzy consistent matrix, a kind of combined operation for several fuzzy consistent matrixes is presented which reflects most opinions of experienced experts. Finally, a practical example shows its flexibility and practicability further.
LMI-based approach for global asymptotic stability analysis of continuous BAM neural networks
ZHANG Sen-lin, LIU Mei-qin
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2005, 6(1): 5-.   https://doi.org/10.1631/jzus.2005.A0032
Abstract( 2299 )     PDF(0KB)( 1047 )
Studies on the stability of the equilibrium points of continuous bidirectional associative memory (BAM) neural network have yielded many useful results. A novel neural network model called standard neural network model (SNNM) is advanced. By using state affine transformation, the BAM neural networks were converted to SNNMs. Some sufficient conditions for the global asymptotic stability of continuous BAM neural networks were derived from studies on the SNNMs?ˉ stability. These conditions were formulated as easily verifiable linear matrix inequalities (LMIs), whose conservativeness is relatively low. The approach proposed extends the known stability results, and can also be applied to other forms of recurrent neural networks (RNNs).
A novel constant modulus array for multiuser detection
ZHANG Ji-dong, ZHENG Bao-yu, FU Hong-liang
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2005, 6(1): 6-.   https://doi.org/10.1631/jzus.2005.A0038
Abstract( 2288 )     PDF(0KB)( 982 )
This paper proposes a new multitarget constant modulus array structure for code division multiple access (CDMA) systems. The new algorithm for the structure is called pre-despreading and wavelet denoising constant modulus algorithm (D-WD-CMA). In the new algorithm, the pre-despreading is applied to multitarget arrays to remove some multiple access interferences. After that the received signal is subjected to wavelet de-noising to reduce some noise, and used in CMA adaptive iteration for signal separation. Simulation results showed that the proposed algorithm performed better than the traditional CMA algorithm.
A high fidelity VQ coding algorithm with region adaptive subbanding
YANG Zhong-qi, BAI Zhi-can, LI Dong-mei, YANG Chang-sheng
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2005, 6(1): 7-.   https://doi.org/10.1631/jzus.2005.A0043
Abstract( 2208 )     PDF(0KB)( 1038 )
Image subbands can be obtained by using filterbank. Traditional compression method uses direct entropy coding for each subband. After studying the energy distribution in image subbands, we proposed a vector quantization (VQ) coding algorithm to image subband. In the algorithm, vector quantizers were adaptively designed for high-frequency bands in an image. In particular, the edges of the image were examined and fewer bits were assigned to high-energy regions. The experimental result showed that the algorithm had higher SNR and higher compression ratio than possible by traditional subband coding, JPEG and JPEG 2000.
An improved TF-IDF approach for text classification
ZHANG Yun-tao, GONG Ling, WANG Yong-cheng
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2005, 6(1): 8-.   https://doi.org/10.1631/jzus.2005.A0049
Abstract( 3945 )     PDF(0KB)( 2522 )
This paper presents a new improved term frequency/inverse document frequency (TF-IDF) approach which uses confidence, support and characteristic words to enhance the recall and precision of text classification. Synonyms defined by a lexicon are processed in the improved TF-IDF approach. We detailedly discuss and analyze the relationship among confidence, recall and precision. The experiments based on science and technology gave promising results that the new TF-IDF approach improves the precision and recall of text classification compared with the conventional TF-IDF approach.
Computer & Information Science
Hybrid heuristic and mathematical programming in oil pipelines networks: Use of immigrants
DE LA CRUZ J.M., HERRÁN-GONZÁLEZ A., RISCO-MARTÍN J.L., ANDRÉS-TORO B.
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2005, 6(1): 9-19.   https://doi.org/10.1631/jzus.2005.A0009
Abstract( 2530 )     PDF(0KB)( 977 )
We solve the problem of petroleum products distribution through oil pipelines networks. This problem is modelled and solved using two techniques: A heuristic method like a multiobjective evolutionary algorithm and Mathematical Programming. In the multiobjective evolutionary algorithm, several objective functions are defined to express the goals of the solutions as well as the preferences among them. Some constraints are included as hard objective functions and some are evaluated through a repairing function to avoid infeasible solutions. In the Mathematical Programming approach the multiobjective optimization is solved using the Constraint Method in Mixed Integer Linear Programming. Some constraints of the mathematical model are nonlinear, so they are linearized. The results obtained with both methods for one concrete network are presented. They are compared with a hybrid solution, where we use the results obtained by Mathematical Programming as the seed of the evolutionary algorithm.
Applying two channels to vector space secret sharing based multi-signature scheme
XIAO Qing-hua, PING Ling-di, CHEN Xiao-ping, PAN Xue-zeng
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2005, 6(1): 9-.   https://doi.org/10.1631/jzus.2005.A0056
Abstract( 2213 )     PDF(0KB)( 917 )
Secret sharing and digital signature is an important research area in information security and has wide applications in such fields as safeguarding and legal use of confidential information, secure multiparty computation and electronic commerce. But up to
A statistical information-based clustering approach in distance space
YUE Shi-hong, LI Ping, GUO Ji-dong, ZHOU Shui-geng
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2005, 6(1): 11-.   https://doi.org/10.1631/jzus.2005.A0071
Abstract( 2422 )     PDF(0KB)( 1196 )
Clustering, as a powerful data mining technique for discovering interesting data distributions and patterns in the underlying database, is used in many fields, such as statistical data analysis, pattern recognition, image processing, and other business ap
Deterministic and randomized scheduling problems under the lp norm on two identical machines
LIN Ling, TAN Zhi-yi, HE Yong
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2005, 6(1): 20-26.   https://doi.org/10.1631/jzus.2005.A0020
Abstract( 2149 )     PDF(0KB)( 984 )
Parallel machine scheduling problems, which are important discrete optimization problems, may occur in many applications. For example, load balancing in network communication channel assignment, parallel processing in large-size computing, task arrangement in flexible manufacturing systems, etc., are multiprocessor scheduling problem. In the traditional parallel machine scheduling problems, it is assumed that the problems are considered in offline or online environment. But in practice, problems are often not really offline or online but somehow in-between. This means that, with respect to the online problem, some further information about the tasks is available, which allows the improvement of the performance of the best possible algorithms. Problems of this class are called semi-online ones. In this paper, the semi-online problem P2|decr|lp (p>1) is considered where jobs come in non-increasing order of their processing times and the objective is to minimize the sum of the lp norm of every machine’s load. It is shown that LS algorithm is optimal for any lp norm, which extends the results known in the literature. Furthermore, randomized lower bounds for the problems P2|online|lp and P2|decr|lp are presented.
Tools to make C programs safe: a deeper study
WANG Ji-min, PING Ling-di, PAN Xue-zeng, SHEN Hai-bin, YAN Xiao-lang
Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2005, 6(1): 63-70.   https://doi.org/10.1631/jzus.2005.A0063
Abstract( 2183 )     PDF(0KB)( 1060 )
The C programming language is expressive and flexible, but not safe; as its expressive power and flexibility are obtained through unsafe language features, and improper use of these features can lead to program bugs whose causes are hard to identify. Since C is widely used, and it is impractical to rewrite all existing C programs in safe languages, so ways must be found to make C programs safe. This paper deals with the unsafe features of C and presents a survey on existing solutions to make C programs safe. We have studied binary-level instrumentation tools, source checkers, source-level instrumentation tools and safe dialects of C, and present a comparison of different solutions, summarized the strengths and weaknesses of different classes of solutions, and show measures that could possibly improve the accuracy or alleviate the overhead of existing solutions.
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