Applied Mechanics and Materials Vols. 20-23

Abstract: Six distribution model tested by D、A2、W2 statistics of 249 bridge crane load spectrum sample in a week. The results show that distribution model hypothesis, distribution testing methods, significant level all impact the testing results. Three-parameter Weibull distribution fit the bridge crane load spectrum best compared with the other distribution model.

Abstract: In the paper, we analyzed optimization algorithms for proxy signature and presented an optimized proxy signature scheme based on discrete logarithm cryptosystem. In the scheme, the signature entrusting parameters are generated with private keys of original signer and the proxy signer; dishonest proxy signer and outer adversaries can not attack secret parameters or other proxy signature with feasible polynomial algorithm, thus the scheme provides effective protection for the secrecy of proxy signers and also renders reasonable supervision on the proxy right. By utilizing random algorithms in signature generating, the scheme avoids the relevance between different parameters and proxy signature from the same signer. Then we presented an improved proxy signature scheme based on ECC (Elliptic Curves Cryptosystem), the scheme well satisfies the requirement of proxy signature and also makes full use of the superiority of ECC, such as high efficiency and security. Therefore, the scheme proves to be applicable to integrated environment with limited system resources.

Abstract: For the realization of remaining fatigue life estimation, prevention of catastrophic accidents and safety of the cranes in service, it is necessary to obtain the actual load spectrum of overhead traveling crane. Due to the limitation of condition in field experiment, it is difficult to implement a large number of actual Load Spectrum experiments. So, the present paper will focus on overhead traveling cranes for general purpose and conduct data investigation. In a certain period，the numbers of work cycles corresponding to different lifting loads for different rated lifting capacity are collected. Based on Levenberg-Marquardt Back Propagation(LMBP) Artificial Neural Network(ANN), the equivalent load spectrum, which is equivalent to the actual load spectrum, is acquired. The example demonstrates: It is feasible to establish the equivalent load spectrum for some types of crane using ANN. Meanwhile, the equivalent load spectrums of the typical cranes in this type could be obtained and predicted through the trained network. It has provided the reliable data for the reliability analysis and fatigue life estimation of the crane. In the approach to establish the crane load spectrum, an exploring and initiating study work have been done.

Abstract: In the paper, we analyzed the system optimization algorithms in e-cash (electronic cash) by improving the efficiency of e-cash for software and hardware application. As for the fast asymmetric cryptography algorithms in e-cash scheme, we presented basic interactive protocols based on discrete logarithm cryptosystem. In the protocol, the interacting algorithms achieve authenticated encryption in secret transmission algorithms, the verification of signature and transmission of secret message can be fulfilled in a single algorithm, and therefore the complexity of authentication algorithms in e-cash scheme is greatly reduced. As a comparison with traditional e-cash schemes, we presented an optimized e-cash scheme based on ECC (Elliptic Curves Cryptosystem). The cryptography algorithms of the scheme make full use of the superiority of ECC fast algorithms, thus the optimized e-cash scheme effectively avoids illegal distribution of e-cash and generalized forgery attack on system parameters with less system overheads.

Abstract: System optimization for key management is an essential method to facilitate the wide application of key management in cryptography protocols. In the paper, we presented a threshold recovering algorithm for key distribution protocols. In the algorithm, the private keys from KGC (Key Generating Center) is encrypted and then shared among the applier members. The attack on the encrypted private keys and the threshold scheme proves computationally infeasible with exponent complexity. Besides, the threshold recovering algorithm is independent of the KGC without leakage of private information of the subgroup; therefore the threshold recovering of private keys renders effective protection for the secrecy of private parameters and applier identity. As to the efficiency of key management algorithms, we presented improved authenticated encryption scheme for key management. In the scheme, the secret transmission of essential parameters is reinforced with integrity and authenticity verification algorithms in an integrated mode; thus greatly improves the efficiency of key management.

Abstract: As a typical fast public key cryptosystem, HCC (Hyper-elliptic Curves Cryptosystem) provides efficient asymmetric algorithms for cryptography schemes. In the paper, we presented an improved authenticated encryption scheme based on HCC as a prototype of signcryption scheme. In the scheme, data encryption and signature generation can be achieved in a single formula and signature verifying protocol is also the decryption algorithm. Therefore, the scheme achieves secret message transmission and authentication simultaneously in one protocol. The scheme renders effective secrecy protection for message receiver; the attack on the authenticated signature and random parameters via the cipher-text is computationally infeasible. The designing strategy of message recovery signature reinforces the security and reliability of authenticated encryption and greatly improves its efficiency for software and hardware application. As a generalization of the authenticated encryption scheme, we presented a signcryption scheme based on HCC. The scheme makes full use of the superiority of fast asymmetric cryptosystem and effectively improves the application efficiency of signcryption for integrated environment.

Abstract: With the rapid increasing of web data, deep web is the fastest growing web data carrier. Therefore, the research of deep web, especially on extracting data records from Result pages, has already become an urgent task. We present a data records extraction based on Global Schema method, which automatically extracts the query result records from web pages. This method first analyzes the Query interface and result records instances to build a Global Schema by ontology. Then, the Global Schema is used in the process of extracting data records from result pages and storing these data in a table. Experimental results indicate that this method is accurate to extract data records, as well as to save in a table with a Global Schema.

Abstract: In this paper, we design and construct a multi-label image annotation and retrieval system. Various MPEG-7 low level visual features are employed for representing images. For image annotation, a bi-coded genetic algorithm is employed to select optimal feature subsets and corresponding optimal weights for every one vs. one SVM classifiers. After an unlabelled image is segmented into several regions, pre-trained SVMs are used to annotate each region, final label is obtained by merging all the region labels. Based on multi-label of image, image retrieval system provides keyword-based image retrieval service. Multi-labels can provide abundant descriptions for image content in semantic level, high precision annotation algorithm further improve annotation performance.

Abstract: In this paper, it analyses Chan and Taylor location algorithms. And a cooperative location method based on Chan and Taylor algorithms is proposed. The new location method is simulated and the results show that the location accuracy of the cooperative method is improved.

Abstract: The sensitive mechanism of the airflow tilt sensor was analyzed by finite element method. The streamfield caused by heat source, when the three-dimensional enclosure inclining, has been obtained by a series of procedure,such as model building, meshing, loads applying and equation solving. In the process, ANSYS-FLOTRAN CFD program is employed. In horizontal status, the velocity of gas flow is equal at the two thermistor wires; therefore the current of both wires are also equal and the output of the bridge circuit is zero. In tilting status, the velocity difference of gas flow at the two thermistor wires will change with the tilt angle; therefore lead to changing of the current difference of both wires, the bridge outputs avoltage signal corresponding to the tilt angle. This calculation method provides a new approach to optimization of airflow tilt sensors.