676909
Real-time multiple objects tracking with occlusion handling in dynamic scenes
This work presents a real-time system for multiple objects tracking in dynamic scenes. A unique characteristic of the system is its ability to cope with long-duration and complete occlusion without a prior knowledge about the shape or motion of objects. The system produces good segment and tracking results at a frame rate of 15-20 fps for image size of 320 /spl times/ 240, as demonstrated by extensive experiments performed using video sequences under different conditions indoor and outdoor with long-duration and complete occlusions in changing background.
218270
Cryptanalysis of a multistage encryption system
This paper analyzes the security of a new multistage encryption system (MES) recently proposed in ISCAS'2004. It is found that MES is insecure against a differential chosen-plaintext/ciphertext attack. Experiments are given to support the proposed attack. It is also pointed out that the security of MES against brute-force attacks is not sufficiently high.
5900866
Breaking network security based on synchronized chaos
Very recently, the use of chaos synchronization as a means of masking information data in a network has been proposed. Although it is claimed that the security breach is not possible and that the proposed encryption approach can be used to secure communications over Internet, we prove that these claims are unfounded, breaking the cryptosystem in different ways.
2501834
On the security of the Yen-Guo's domino signal encryption algorithm (DSEA)
Recently, a new domino signal encryption algorithm (DSEA) was proposed for digital signal transmission, especially for digital images and videos. This paper analyzes the security of DSEA, and points out the following weaknesses: (1) its security against the brute-force attack was overestimated; (2) it is not sufficiently secure against ciphertext-only attacks, and only one ciphertext is enough to get some information about the plaintext and to break the value of a sub-key; (3) it is insecure against known/chosen-plaintext attacks, in the sense that the secret key can be recovered from a number of continuous bytes of only one known/chosen plaintext and the corresponding ciphertext. Experimental results are given to show the performance of the proposed attacks, and some countermeasures are discussed to improve DSEA.
18473631
Cryptanalysis of a Chaotic Neural Network Based Multimedia Encryption Scheme
Recently, Yen and Guo proposed a chaotic neural network (CNN) for signal encryption, which was suggested as a solution for protection of digital images and videos. The present paper evaluates the security of this CNN-based encryption scheme, and points out that it is not secure from the cryptographical point of view: 1) it can be easily broken by known/chosen-plaintext attacks; 2) its security against the brute-force attack was much over-estimated. Some experiments are shown to support the results given in this paper. It is also discussed how to improve the encryption scheme.
3106412
On the Design of Perceptual MPEG-Video Encryption Algorithms
In this paper, some existing perceptual encryption algorithms of MPEG videos are reviewed and some problems, especially security defects of two recently proposed MPEG-video perceptual encryption schemes, are pointed out. Then, a simpler and more effective design is suggested, which selectively encrypts fixed-length codewords in MPEG-video bit streams under the control of three perceptibility factors. The proposed design is actually an encryption configuration that can work with any stream cipher or block cipher. Compared with the previously-proposed schemes, the new design provides more useful features, such as strict size-preservation, on-the-fly encryption and multiple perceptibility, which make it possible to support more applications with different requirements. In addition, four different measures are suggested to provide better security against known/chosen-plaintext attacks
15596549
AgentStra: an Internet-based multi-agent intelligent system for strategic decision-making
This article reports the development and experimental evaluation of an Internet-enabled multi-agent prototype system, called AgentStra, for developing marketing strategies, competitive strategies and associated IT/IS/e-commerce strategies. Firstly, the multi-agent architecture of the AgentStra system is presented with relevant strategy agents described. Secondly, the logical flow and screen examples of the system execution are illustrated with guidelines on coupling AgentStra with human judgement proposed. Thirdly, the pilot evaluation of the system's effectiveness and efficiency is documented with preliminary findings discussed. Finally, the conclusions are drawn with further research work envisaged.
2426410
Network information flow
We introduce a new class of problems called network information flow which is inspired by computer network applications. Consider a point-to-point communication network on which a number of information sources are to be multicast to certain sets of destinations. We assume that the information sources are mutually independent. The problem is to characterize the admissible coding rate region. This model subsumes all previously studied models along the same line. We study the problem with one information source, and we have obtained a simple characterization of the admissible coding rate region. Our result can be regarded as the max-flow min-cut theorem for network information flow. Contrary to one's intuition, our work reveals that it is in general not optimal to regard the information to be multicast as a "fluid" which can simply be routed or replicated. Rather, by employing coding at the nodes, which we refer to as network coding, bandwidth can in general be saved. This finding may have significant impact on future design of switching systems.
37409414
Algorithms for flow control and call set-up in multi-hop broadband ISDN
An algorithm for the decentralized control of traffic flow in multihop broadband ISDN and a concomitant algorithm for call setup are proposed. The approach in flow control is to strategically detain packets at points along their routes in anticipation of probable congestion ahead of them. The goal is to avoid buffer overflowing caused by concentrated packet accumulation at a single node on the network. A typical traffic control decision involves just two primitive operations: a READ and a logical AND. Hence, a submicrosecond execution time is expected. This quickness enables the traffic control to be implementable on the packet (or cell) level for broadband communications with a moderate packet size. This algorithm also strives for high utilization of broadband facilities and preserves the order among sequential packets. The concomitant algorithm for call setup is solely executed at the traffic originating node(s) and thus requires no internode communications. This leads to a simple process of calls setup that ensures the continuous flow of ongoing calls and, at the same time, avoids buffer overflowing.<<ETX>>
16413633
Feature analysis for service-oriented reengineering
Web services together with service-oriented architectures (SOA) are playing an important role in the future of distributed computing, significantly impacting software development and evolution. With the adoption to Web services technology, more and more existing non-service-oriented software systems turn to be legacy systems. They require a service-oriented reengineering process in order to survive in service-oriented computing environment. If the reengineering goal is to expose the services of a single object or any underlying function-oriented middleware, many problems will arise including semantic mismatches, service granularity issues and state management. Attempting to masquerade software assets from a lower level of abstraction can often cause significant mismatch and exposure problems. In this paper, by using feature analysis, an approach to supporting service-oriented reengineering is presented. Service identification and packaging process are performed and resulted into a service delegation.
5823379
"BIRON, let me show you something": evaluating the interaction with a robot companion
Current research on the interaction with a robot is driven by the desire to build intuitive and natural interaction schemes. In order for our robot BIRON to behave naturally we integrated an attention system that enables the robot to search for and eventually focus on human communication partners by detecting and tracking persons. Via a natural language interface the user can then interact with BIRON and teach him new objects or ask him to follow her. First valuation results from 21 users interacting with the robot indicate that users appreciate the natural language capabilities of BIRON. However, users are very sensitive to speech recognition failures even though all of our subjects had prior experience with speech recognition systems. The results also indicate that feedback on the internal status of the robot is extremely helpful for users.