15925751
SpMT WaveCache: Exploiting Thread-Level Parallelism in WaveScalar
Speculative Multithreading (SpMT) increases the performance by means of executing multiple threads speculatively to exploit thread-level parallelism. By combining software and hardware approaches, we have improved the capabilities of previous WaveScalar ISA on the basis of Transactional Memory system for the WaveCache Architecture. Threads are extracted at the course of static compiling, and speculatively executed as a thread-level transaction that is supported by extra hardware components, such as Thread-Context-Table (TCT) and Thread-Memory-History (TMH). We have evaluated the SpMT WaveCache with 6 real benchmarks from SPEC, Mediabench and Mibench. On the whole, the SpMT WaveCache outperforms superscalar architecture ranging from 2X to 3X, and great performance gains are achieved over original WaveCache and Transactional WaveCache as well.
16070632
Prototyping system of codec for novel 2-D continuous barcode
To address the limits of capacity and the disadvantages of motional scanning capability of traditional two-dimensional (2-D) barcodes, a novel 2- D continuous barcode (2-D CoBe) with improving the structure of traditional 2-D barcodes is proposed. The novel barcode not only enable to store a large mount of data with indefinitive capacity, but also support realtime decoding. Furthermore, a prototyping system of codec including encoding sub-system and decoding sub-system is examined and implemented. In this codec system, 2-D CoBe can be generated and printed on papers by encoding software sub-system. Besides, it can be recognized and decoded by a hand-held device with decoding sub-system in real-time. Based on the experimental results of encoding binary voice data into 2-D CoBe and decoding it with a hand-held device, it is verified that the codec system for 2-D CoBe is practical and effective.
7188468
GPGPU supported cooperative acceleration in molecular dynamics
Molecular dynamics simulations have become a significant computational approach to study complicated physical phenomena at the atomic level. Nevertheless, accurate simulations are limited in size and timescale by the available computing resources, which make the simulations very time-consuming. This consequentially leads to tremendous computational requirements. Therefore, the need for speeding up this process is crucial. In this paper, we present a novel implementation to accelerate molecular dynamics simulations with GPGPU (General Purpose Graphics Processing Unit). Our goal is to reduce the total computational time of MD simulations at a very high performance/cost ratio with the introduction of the GPGPU algorithm. This is motivated by their enhanced programmability, attractive cost/performance ratio and incredible growth in speed. To demonstrate that GPGPUs already provide an inexpensive alternative to scientific applications, we have used AMD's Brook+ streaming programming environment to implement a new parallel algorithm. Our experimental results show the novel approach achieves speedup by the factor of fifteen compared to the corresponding sequential implementation.
26669443
Bottom-up discovery of frequent rooted unordered subtrees
In the past decade, XML has emerged as the standard language for information exchanging over the Internet. Due to its tree-structure paradigm, XML is superior for its capability of storing, querying, and manipulating complex data. Therefore, discovering frequent tree patterns over tree-structured data has become an interesting topic for XML data management. In this paper, we propose a tree mining algorithm, named BUXMiner, for finding a special class of frequent trees, called rooted unordered trees, from a tree-structured database. BUXMiner employs an efficient bottom-up approach to enumerate all candidate trees over a compact global tree guide and computes the frequent trees based on the tree guide. In addition to BUXMiner, we also propose a mining approach called BUMXMiner to discover the maximal frequent rooted unordered trees. We compare BUXMiner with previous tree-structure mining algorithms, namely XQPMinerTID and FastXMiner, which were also proposed to discover rooted unordered trees. The experimental results show that our algorithm outperforms XQPMinerTID and FastXMiner in terms of efficiency. The performance results from real-world applications also indicate the usefulness of our proposed tree mining algorithms in a variety of web applications, such as analysis of web page access patterns and mining frequent XML query patterns for caching.
40279092
An Audio Feature Extraction Method Taking Class Information into Account
An inverter ballast for fluorescent lamps utilizing a resonant circuit coupled to the lamp and operated from a source of DC power through transistors. The transistors are controlled by a sensing means in the resonant loop which insures that the transistor switch at zero current. Furthermore, the coupling means for the load controls a source of heater voltage to the anodes of the fluorescent light which operate at very low current, an antisaturation circuit made up of separate windings are on the current transformer and connected to the switching transistor bases and through diodes to the power supply to prevent "shoot through" current in the transistors. An autotransformer is used as a high leakage reactance transformer; and a circuit is provided to prevent overload of the resonant circuit in case of lamp failure. Shoot through currents are prevented, and overload of the resonant circuit is prevented, and an autotransformer coupling of the resonant circuit to the load is used.
15894335
An adaptive load balancing framework for parallel database systems based on collaborative agents
Load balancing is a key technique in parallel computer supported collaborative work (CSCW) systems, parallel database system and P2P system for instance, to boost performance and improve scalability. In order to reduce total cost of ownership (TCO), adaptive/self-tuning administration techniques are gradually and extensively expected in the cyberspace. In parallel database systems, adaptive load balancing techniques are proposed to face the change in data storage patterns and access patterns in a dynamic real environment. The techniques utilized in both shared-nothing and shared-disk parallel database systems are discussed, and a general flexible framework based on collaborative agents is studied to support these techniques in both architectures. The framework supports two kinds of load balancing - one is passively executing query statements balancedly, and the other one is proactively adjusting data placement and task execution scheme, by means of data and task migration, whenever load unbalance is detected. Three categories of agents, scheduling agents, monitoring agents and task agents, are identified in the framework. The collaboration protocols and scheduling algorithms to support adaptive load balancing are described. The framework also applies to other parallel systems such as P2P systems and shared file processing systems due to their underlying commonness.
17839950
Reorganizing global schedules for register allocation
Instruction scheduling is an important compiler technique for exploiting more instruction-level parallelism (ILP) in high-performance microprocessors, and in this paper, we study how to perform global instruction scheduling before register allocation (prepass scheduling) for control-intensive non-numerical applications. As the number of parallel function units in modern microprocessors has increased, compiler writers have increased the size of prepass scheduling regions and the number of speculative operations scheduled. However, if prepass scheduling is not carefully managed, it is easy to create places in a prepass schedule that require more register resources than are architecturally available. We propose an approach that maintains the effectiveness of prepass scheduling in exploiting ILP even with the constraint of a limited number of architectural registers. In particular, we show that the pairing of a greedy prepass scheduler with a code reorganizer performs significantly better than the common approach of using a single register-pressure-sensitive scheduler. Our experimental results show that our non-backtracking, codereorganizing algorithm can eliminate most of the excessive register pressure created by greedy ILP scheduling, and thus improve the overall performance of the globally scheduled regions.
17947344
Enhancing Search Performance in Unstructured P2P Networks Based on Users' Common Interest
Peer-to-peer (P2P) networks establish loosely coupled application-level overlays on top of the Internet to facilitate efficient sharing of resources. They can be roughly classified as either structured or unstructured networks. Without stringent constraints over the network topology, unstructured P2P networks can be constructed very efficiently and are therefore considered suitable to the Internet environment. However, the random search strategies adopted by these networks usually perform poorly with a large network size. In this paper, we seek to enhance the search performance in unstructured P2P networks through exploiting users' common interest patterns captured within a probability-theoretic framework termed the user interest model (UIM). A search protocol and a routing table updating protocol are further proposed in order to expedite the search process through self organizing the P2P network into a small world. Both theoretical and experimental analyses are conducted and demonstrated the effectiveness and efficiency of our approach.