38129543
Enhanced Verification-Based Decoding for Packet-Based LDPC Codes over Wireless Channels
In this paper, we apply the enhanced verification-based decoding algorithm (EVA) for packet-based LDPC codes over wireless channels. Compared with the verification algorithm (VA) in the literature, the EVA algorithm enhances the verification condition thereby reducing the likelihood of false verification. The wireless channels in simulations are modeled by binary symmetric channel (BSC) and Gilbert-Elliott (GE) channel. The numerical results indicate the proposed algorithm gives a superior performance but with only moderate computation increase compared with VA. For example, when the bit error probability is less than 10-3 in bad state of GE channel, the EVA reduces the frame error rate (FER) by one order with less than 35% complexity increase compared with VA.
6431667
Performance Analysis of Verification-Based Decoding for Packet-Based LDPC Codes over Binary Symmetric Channel
In this paper, we propose a statistical model to analyze the performance of verification-based algorithm (VA) for packet-based low-density parity-check (LDPC) codes over binary symmetric channel (BSC). In contrast to the analysis of VA in the literature, we propose to take the false verification into consideration. For a given ensemble of LDPC codes and channel parameters, the proposed analysis model gives an efficient way to find the average performance of packet-based LDPC codes with verification-based decoding. Through numerical results, we find that the proposed method can provide a close estimation of frame error rate (FER) for packet-based LDPC codes with verification-based decoding over BSC for all crossover probabilities of practical interests.
45804784
A new one-and-half layer channel routing algorithm based on assigning resources for CMOS gate array
It is demonstrated that sufficient and reasonable utilization of the constrained horizontal and vertical routing resources is the key to achieving a high completion rate in this one-and-one-half layer routing approach. By using the minimum intersection graph to order the nets, the number of intersections among the nets is minimum, the number of intersection columns is as small as possible, and the total length of poly-bars used in wiring is as short as possible. From this the requirements for the horizontal and vertical routing resources are as few as possible. A reasonable assignment of the horizontal routing resources can be achieved by operating the active track matrices of the nets at the predicted columns, while the optimal assignment of the vertical routing resources is obtained by using the cluster assignment algorithm of the incidence intersection columns. Guided by the wiring tracks in the predicted columns and using the poly-bars assigned, the channel routing can be implemented with high performance by scanning the channel from left to right and column by column. >
9382607
User-interface Design of Web Application Using Object-Z
A notation is presented for formally describing Web application’s design of a user-interface. The function of a Web application is given using formal specification language Object-Z and then some generic classes, relationships and system actions are defined to specify user-interface design. In user-interface design, UAN annotations are added to Object-Z notation. The extended Object-Z notation expresses the presentation relationship between the design and the specification. This formal specification and design is useful in documenting a user-interface design and enables the analysis of the usability and safety of a Web application. In particular, it can be used to generate test cases automatically. An example of student information management system is used to illustrate the notation. Task efficiency is analyzed with the example.
5048240
Current state of the art, challenges and future directions for audio watermarking
Transparent data embedding algorithms embed binary streams in host multimedia signals. The embedded data is perceptually inaudible to maintain the quality of the source data. The embedded data can add features to the host multimedia signal or provide copyright protection. We review developments and requirements in transparent data embedding techniques for audio signals. We describe our latest audio embedding algorithm and include experimental results indicating robustness to low bit rate MPEG-Layer 3, AAC, and Dolby AC-3 coding. We conclude with a discussion of future research directions.
12614266
SVision: A Network Host-Centered Anomaly Visualization Technique
We proposed a technique merged from a combination of both anomaly and graphical methods, for intrusion detection. The network is pictured as a community of hosts that exchange messages among themselves. Our aim is to graphically highlight those hosts that represent a possible threat for the network, so that a network administrator will be able to further explore the anomaly and decide upon the responses that are appropriate. We choose to test our view against the DARPA 99 intrusion detection and evaluation dataset since it provides labels which we can use to monitor our system. Experiments show our visualization technique as a possible alternative for detection of network intrusions, in particular Denial of Service (DoS) and Distributed-DoS attacks such as Ping Of Death, UDP storm, SSH Process Table, and Smurf, to name a few.
32302991
Image coding by folding
We propose an image coding algorithm which employs data hiding techniques to "fold" an image into itself. Data hiding is a process of encoding extra information into a host image by making small modifications to its pixels. In our approach, an image is split into two parts of equal size: a host image and a residual image. The residual image is compressed into a bit stream and then embedded into the host image. The host image, which is 50% of the size of the original image, is coded using standard compression techniques. The embedded data does not increase the bit rate of the coded image. As a result, one may code only 50% pixels of the original image and still have perfect reconstruction. Experimental results indicate that the algorithm has a lot of potential in image coding.