Hu Mingzeng

A VLSI architecture design of CAVLC decoder

Variable length code is an integral component of many international standards on image and video compression. Recently, context-based adaptive variable length coding (CAVLC) is adopted by the emerging JVT (also called H.264 in ITU, and AVC in MPEG-4). In this paper, we describe a novel architecture for CAVLC decoder, including a coeff_token decoder, level decoder, total_zeros decoder and run_before decoder. Together with a barrel shifter and controller, the pipeline architecture can decode every syntax element in one clock cycle. Therefore, it is very suitable for video applications that require high throughput.Variable length code is an integral component of many international standards on image and video compression. Recently, context-based adaptive variable length coding (CAVLC) is adopted by the emerging JVT (also called H.264 in ITU, and AVC in MPEG-4). In this paper, we describe a novel architecture for CAVLC decoder, including a coeff_token decoder, level decoder, total_zeros decoder and run_before decoder. Together with a barrel shifter and controller, the pipeline architecture can decode every syntax element in one clock cycle. Therefore, it is very suitable for video applications that require high throughput.

A novel distributed intrusion detection model based on mobile agent

Distributed intrusion detection is one of the most promising information security techniques. It is used to detect various attacks from distributed network environment. But attack behaviors are becoming more complicated with the development of network techniques so that it is becoming more difficult to detect them. In order to overcome the shortcomings of current intrusion detection techniques, a novel hierarchical model of multi-level detection intrusion is proposed. The model utilizes the intelligent, mobile and self-adaptive characteristics of agent and its distributed collaborative calculation capability. So it can detect complicated attacks effectively. The adoption of the clone and migration mechanism of agent and the security communication protocol enhances the security and collaborative detection capability of the model. communication load is reduced effectively and intrusions can be detected and responded as quickly as possible. The model can evolve and adjust itself dynamically to adapt to the external environmental change. The model is robust and scalable.

Multisite co-allocation scheduling algorithms for parallel jobs in computing grid environments

Cooperation of multi-domain massively parallel processor systems in computing grid environment provides new opportunities for multisite job scheduling. At the same time, in the area of co-allocation, heterogeneity, network adaptability and scalability raise the challenge for the international design of multisite job scheduling models and algorithms. It presents multisite job scheduling schema through the introduction of multisite job scheduling model and the performance model under the grid environment. It introduces two job multisite and cooperative scheduling models and algorithms with the core of the optimal and greedy-heuristic resource selection strategies. Meanwhile, compared with single and multisite cooperative scheduling models and algorithms introduced by Sabin, Yahyapour and other persons, the validity and advance of the scheduling model and the performance model herein are proved.

A distributed architecture for Internet router level topology discovering systems

In the past five years, hosts on the Internet have multiplied more than five times, and along with the networks rapid expansion, more and more attention is paid to the challenging task of studying the topology characteristics of Internet infrastructure. Based on the features of Internet topology discovery and practical experience, we present a three-level distributed architecture for Internet router-level routing topology discovering system. We employ an integrated framework for the deployment of the system. We are examining, from a macroscopic point of view, what architecture is appropriate for this-like system, with an emphasis placed on the flexibility in practical work. The architecture enjoys the advantages of a clear train of thought and high modularization. Experiments show that this architecture has an instructive meaning for the development, deployment, and maintenance of Internet topology discovering system.

A supporting service differentiation multichannel MAC protocol for wireless ad hoc networks

Providing service differentiation by using distributed control at the MAC layer is an effective mechanism for supporting Quality of Service (QoS) in wireless ad hoc networks. However, existing QoS-capable MAC protocols have been designed in single channel environments. Multichannel technology has been demonstrated to significantly increase network capacity, reduce chances of contention and collision of data transmission. So, QoS guarantee is easier to achieve by using multichannel technology. In this paper, we devise a supporting service differentiation multichannel MAC protocol. Two interfaces are used, an interface staying at common control channel is responsible for assigning data channel and another can dynamically switch channel for data transmission. In the common control channel, different priority flows adopt different backoff parameters to access channel to acquire data channel assignment chance. Simulation results show the protocol outperforms Enhanced Distributed Coordination Function (EDCF) of IEEE 802.11e.

Simultaneous Multithreading Fault Tolerance Processor

Transient fault detection mechanism is added to simultaneous multithreading architecture. By exploiting both ILP (Instruction Level Parallelism) and TLP (Thread Level Parallelism), Simultaneous Multithreading (SMT) Fault Tolerance Processor can be expected to achieve better tradeoff between performance and hardware cost than traditional Fault Tolerance Processors. Detailed simulations of 3 of SPEC95 benchmarks show that executing two redundant programs on the fault-tolerant microarchitecture takes only 40%–61% longer than running a single version of the program. The new instruction fetch algorithm enhances the performance by 0.4% ∼1% to most of the benchmarks we choose randomly.

A Tree-structured Database Machine for large relational database systems

This paper proposes a Tree-structured Database Machine (TDM), which is designed for supporting large relational database systems. The TDM aims at totally improving three level performance bottlenecks in relational database systems, i.e. IO data transfer bottleneck, data processing bottleneck, and multiquery optimization bottleneck. For reducing these bottlenecks, the TDM provides the approaches of data partition and data distribution upon data storages for concurrent data accesses, the tree-structured multiprocessor architecture for parallel data processing, the technique of tightly-coupled-shared-memory for decreasing data movement, the mechanisms of indices and dictionaries for reducing data transfer from the data storages to the memory, and so on. These features show that the TDM not only improves the system performance, increases the parallelism and the data processing power, but also eliminates the performance bottlenecks in relational database systems.This paper proposes a Tree-structured Database Machine (TDM), which is designed for supporting large relational database systems. The TDM aims at totally improving three level performance bottlenecks in relational database systems, i.e. IO data transfer bottleneck, data processing bottleneck, and multiquery optimization bottleneck. For reducing these bottlenecks, the TDM provides the approaches of data partition and data distribution upon data storages for concurrent data accesses, the tree-structured multiprocessor architecture for parallel data processing, the technique of tightly-coupled-shared-memory for decreasing data movement, the mechanisms of indices and dictionaries for reducing data transfer from the data storages to the memory, and so on. These features show that the TDM not only improves the system performance, increases the parallelism and the data processing power, but also eliminates the performance bottlenecks in relational database systems.