Том 51, № 3 (2017)
- Год: 2017
- Статей: 8
- URL: https://journals.rcsi.science/0146-4116/issue/view/10709
Article
Estimation of stability of oscillations of linear time-varying systems with one time-varying parameter with calculation of influence of higher frequency motions
Аннотация
The paper reveals a new method for estimation of stability of oscillations of linear time invariant systems with one time-varying parameter given by a harmonic function. The suggested approach includes building a matrix of transfer functions, which calculates interference of the highfrequency oscillations of the output of the linear time-invariant part of the system. Suggested approach makes possible to build equivalent of the Nyquist criterion for linear systems with a single time-varying parameter. The application of the suggested approach is shown by numerical examples. Results of the present article may be used for control systems of cranes and other lifting mechanisms.
141-148
Detection of abnormal traffic video images based on high-dimensional fuzzy geometry
Аннотация
Detection of abnormal video images of transportation is to find out video images that contain abnormities among all images of transportation using video and image processing and analyzing techniques. It is an important component of intelligent transportation system, which can not only reduce the workload of traffic managers, but also effectively improve the efficiency of traffic management. However, video images of transportation in practice usually have complex backgrounds, and current detecting algorithms of traffic abnormity sometimes become ineffective due to interference factors such as noises and affine transformation (illumination variation, target occlusion, scale changes and view changes, etc.). In order to overcome these interference factors and fuzzy uncertainties in image representation, as well as improve the accuracy of traffic images representation, this study explored the representation methods of traffic images using fuzzy geometry theory on the basis of fuzzy uncertainties occurring during the process of imaging, transmission and processing of images; moreover, this study also put forward two kinds of representation algorithms of traffic images, and analyzed and verified effectiveness of representation algorithms based on theories and experiments.
149-158
Efficient key insulated attribute based signature without bilinear pairings for mobile communications
Аннотация
Attribute based signature (ABS) is a significant cryptographic notion providing secure authentication during data sharing. A signer can sign a message using the private keys he processes. However, user’s private key exposure may happen from time to time and this will bring potential threat to the whole system. Thus, key evolving mechanism should be introduced into ABS schemes. Besides, the efficiency of existing ABS schemes can be further improved since the process of signing and verification require massive bilinear pairings, which occupies costly computing resources on mobile terminal devices. To better tackle the above problems and provides a more secure data authentication method in mobile communication systems, in this paper, we firstly propose a key insulated attribute based signature scheme without pairings (KI-ABS-WP). Then we give the formalized definition as well as the concreted constructions of our scheme. In our KI-ABS-WP, uses needn’t run any bilinear pairings, thus the total computation cost has been reduced to a large extent. If key exposure occurs, key insulation mechanism guarantees system’s both backward and forward security. Finally, by security proof and efficiency comparison, our KI-ABS-WP is shown to be more superior for data authentication in mobile communication systems.
159-166
Error correction of digital signal processing devices using non-positional modular codes
Аннотация
The paper discusses an algorithm for correcting code errors of the residue number system using a positional characteristic. Application of parallel-pipeline computations of this positional characteristic allows us to reduce hardware costs by 7.2% for processing 2-byte data represented in a residue number system code. The main properties of codes allow us to provide the required fault-tolerance for multi-rate DSP devices. The results provided in the paper can be applied to hydroacoustic monitoring tasks.
167-173
The detection of Udpstorm attacks based on model checking linear temporal logic
Аннотация
The intrusion detection based on model checking temporal logic is effective in detecting the complicated and variable network attacks. However, certain types of attacks remain undetected due to the lack of formal models. To solve this problem, a linear temporal logic is employed to model the variable patterns of Udpstorm attacks. First, an analysis of the principles of Udpstorm attacks is given and the details of these attacks are transformed into atomic actions. The atomic actions are then transformed into action sequence. Finally, this type of attacks is expressed in Linear Temporal Logic (LTL) formulas. With the formula thus obstained used as one input of the model checker and the automaton, which expresses the log, used as the other input of the model checker, the results of intrusion detection can be obtained by conducting the LTL model checking algorithm. The effectiveness and the comparative advantages of the new algorithm are verified by the simulation experiments.
174-179
Scene-specific pedestrian detection based on transfer learning and saliency detection for video surveillance
Аннотация
Pedestrian detection is a fundamental problem in video surveillance and has achieved great progress in recent years. However the performance of a generic pedestrian detector trained on some public datasets drops significantly when it is applied to some specific scenes due to the difference between source training samples and pedestrian samples in target scenes. We propose a novel transfer learning framework, which automatically transfers a generic detector to a scene-specific pedestrian detector without manually labeling training samples from target scenes. In our method, we get initial detected results and several cues are used to filter target templates whose labels we are sure about from the initial detected results. Gaussian mixture model (GMM) is used to get the motion areas in each video frame and some other target samples. The relevancy between target samples and target templates and the relevancy between source samples and target templates are estimated by sparse coding and later used to calculate the weights for source samples and target samples. Saliency detection is an essential work before the relevancy computing between source samples and target templates for eliminating interference of non-salient region. We demonstrate the effectiveness of our scene-specific detector on a public dataset, and compare with the generic detector. Detection rates improves significantly, and also it is comparable with the detector trained by a lot of manually labeled samples from the target scene.
180-192
Multi-cue based moving hand segmentation for gesture recognition
Аннотация
This paper proposes a novel moving hand segmentation approach using skin color, grayscale, depth, and motion cues for gesture recognition. The proposed approach does not depend on unreasonable restrictions, and it can solve the problem of hand-over-face occlusion. First, an online updated skin color histogram (OUSCH) model is built to robustly represent skin color; second, according to the variance information of grayscale and depth optical flow, a motion region of interest (MRoI) is adaptively extracted to locate the moving body part (MBP) and reduce the impact of noise; then, Harris-Affine corners that satisfy skin color and adaptive motion constraints are adopted as skin seed points in the MRoI; next, the skin seed points are grown to obtain a candidate hand region utilizing skin color, depth and motion criteria; finally, boundary depth gradient, skeleton extraction, and shortest path search are employed to segment the moving hand region from the candidate hand region. Experimental results demonstrate that the proposed approach can accurately segment moving hand regions under different situations, especially when the face is occluded by a hand. Furthermore, this approach achieves higher segmentation accuracy than other state-of-the-art approaches.
193-203
Development and realization of embedded car networking vehicle terminal software system
Аннотация
As China’s economy develops vigorously, people’s living quality has been greatly improved and its car ownership has been increasing day by day. Consequently, traffic jams and safety problems become more and more severe. To solve these problems, the idea of car networking system construction has been put forward based on the improvement of Internet of Things and computer technologies. However, the vehicle terminals produced by many automobile manufacturers has disadvantages, such as incomplete functions, incompatible interface and exorbitant costs, etc. Therefore, based on the concept of car networking as well as the new 4G network technique, this study designed a kind of embedded car networking vehicle terminal and analyzed its hardware structure and installation problems. Moreover, its function of boot load program was extended and a software development platform of the embedded vehicle terminal based on Linux core was constructed. On the basis of the software and hardware environment construction, the global position system (GPS) and ZigBee wireless transmission software of the vehicle terminal were designed. In addition, the realization of the function of serial port communication was elaborated, and the development and realization of the embedded car networking vehicle terminal software system were explored.
204-213
