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收集所有交通大學研究人員與學生個人或團體所發表之各項學術著作,涵蓋期刊論文、教師專書、學位論文等項。;;Collections of Publications of NCTU Researchers and Students Like Journal Papers and Thesis.

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Now showing 1 - 10 of 42
  • Item type:Item,
    Hybrid Dandelion: Visual Aesthetics of Performance Through Bionic Mechanism with Data from Biometric Facial Recognition
    (2019-01-01)
    Huang, Scottie Chih-Chieh
    ;
    Hsiao, Chung-Yun
    ;
    資訊工程學系
    ;
    Department of Computer Science
    Hybrid Dandelion is an interactive real-time animation art installation, used bionic mechanisms of algorithmic design to study generative rules for mimic biological form. It provides an approach to combine the algorithmic data structures from distributed computing, fractal tree, and L-system for investigate growth dandelion-like morphology. This work creates an interaction scenario with using facial recognition to scan audience's biometrics as means decoding your genetic data, and then inserting (the trait) into the dandelion model for modifying its indeed generative rules as like metaphor hybrid genetically modified task. It allows the audience to experience their unique data-driven artificial life form - dandelion as embodied and possessed through their facial features, heartbeat signal, and emotion expression in artistic expression.
  • Item type:Item,
    Scan-Cell Reordering for Minimizing Scan-Shift Power Based on Nonspecified Test Cubes
    (2010-11-01)
    Wu, Yu-Ze
    ;
    Chao, Mango C. -T.
    ;
    電子工程學系及電子研究所
    ;
    Department of Electronics Engineering and Institute of Electronics
    This article presents several scan-cell reordering techniques to reduce the signal transitions during the test mode while preserving the don't-care bits in the test patterns for a later optimization. Combined with a pattern-filling technique, the proposed scan-cell reordering techniques can utilize both high response correlations and pattern correlations to simultaneously minimize scan-out and scan-in transitions. Those scan-shift transitions can be further reduced by selectively using the inverse connections between scan cells. In addition, the trade-off between routing overhead and power consumption can also be controlled by the proposed scan-cell reordering techniques. A series of experiments are conducted to demonstrate the effectiveness of each of the proposed techniques individually.
  • Item type:Item,
    Vector-Aware Register Allocation for GPU Shader Processors
    (2015)
    You, Yi-Ping
    ;
    Chen, Szu-Chieh
    ;
    資訊工程學系
    ;
    Department of Computer Science
    Graphics processing units (GPUs) are now widely used in embedded systems for manipulating computer graphics and even for general-purpose computation. However, many embedded systems have to manage highly restricted hardware resources in order to achieve high performance or energy efficiency. The number of registers is one of the common limiting factors in an embedded GPU design. Programs that run with a low number of registers may suffer from high register pressure if register allocation is not properly designed, especially on a GPU in which a register is divided into four elements and each element can be accessed separately, because allocating a register for a vector-type variable that does not contain values in all elements wastes register spaces. In this paper we present a vector-aware register allocation framework to improve register utilization on shader architectures. The framework involves two major components: (1) element-based register allocation that allocates registers based on the element requirement of variables and (2) register packing that rearranges elements of registers in order to increase the number of contiguous free elements, thereby keeping more live variables in registers. Experimental results on a cycle-approximate simulator showed that the proposed framework decreased 92% of register spills in total and made 91.7% of 14 common shader programs spill-free. These results indicate an opportunity for energy management of the space that is used for storing spilled variables, with the framework improving the performance by a geometric mean of 8.3%, 16.3%, and 29.2% for general shader processors in which variables are spilled to memory with 5-, 10-, and 20-cycle access latencies, respectively. Furthermore, the reduction in the register requirement of programs enabled another 11 programs with high register pressure to be runnable on a lightweight GPU.
  • Item type:Item,
    An EDA Framework for Large Scale Hybrid Neuromorphic Computing Systems
    (2015)
    Wen, Wei
    ;
    Wu, Chi-Ruo
    ;
    Hu, Xiaofang
    ;
    Liu, Beiye
    ;
    Ho, Tsung-Yi
    In implementations of neuromorphic computing systems (NCS), memristor and its crossbar topology have been widely used to realize fully connected neural networks. However, many neural networks utilized in real applications often have a sparse connectivity, which is hard to be efficiently mapped to a crossbar structure. Moreover, the scale of the neural networks is normally much larger than that can be offered by the latest integration technology of memristor crossbars. In this work, we propose AutoNCS - an EDA framework that can automate the NCS designs that combine memristor crossbars and discrete synapse modules. The connections of the neural networks are clustered to improve the utilization of the memristor elements in crossbar structures by taking into account the physical design cost of the NCS. Our results show that AutoNCS can substantially enhance the utilization efficiency of memristor crossbars while reducing the wirelength, area and delay of the physical designs of the NCS.
  • Item type:Item,
    Scalable Global Power Management Policy Based on Combinatorial Optimization for Multiprocessors
    (2015-12-01)
    Pan, Gung-Yu
    ;
    Yang, Jed
    ;
    Jou, Jing-Yang
    ;
    Lai, Bo-Cheng Charles
    ;
    交大名義發表
    Multiprocessors have become the main architecture trend in modern systems due to the superior performance; nevertheless, the power consumption remains a critical challenge. Global power management (GPM) aims at dynamically finding the power state combination that satisfies the power budget constraint while maximizing the overall performance (or vice versa). Due to the increasing number of cores in a multiprocessor system, the scalability of GPM policies has become critical when searching satisfactory state combinations within acceptable time. This article proposes a highly scalable policy based on combinatorial optimization with theoretical proofs, whereas previous works take exhaustive search or heuristic methods. The proposed policy first applies an optimum algorithm to construct a state combination table in pseudo polynomial time using dynamic programming. Then, the state combination is assigned to cores with minimum transition cost in linear time by mapping to the network flow problem. Simulation results show that the proposed policy achieves better system performance for any given power budget when compared to the state-of-the-art heuristic. Furthermore, the proposed policy demonstrates its prominent scalability with 125 times faster policy runtime for 512 cores.
  • Item type:Item,
    Efficient Coverage-Driven Stimulus Generation Using Simultaneous SAT Solving, with Application to SystemVerilog
    (2014-11-01)
    Cheng, An-Che
    ;
    Yen, Chia-Chih (Jack)
    ;
    Val, Celina G.
    ;
    Bayless, Sam
    ;
    Hu, Alan J.
    SystemVerilog provides powerful language constructs for verification, and one of them is the covergroup functional coverage model. This model is designed as a complement to assertion verification, that is, it has the advantage of defining cross-coverage over multiple coverage points. In this article, a coverage-driven verification (CDV) approach is formulated as a simultaneous Boolean satisfiability (SAT) problem that is based on covergroups. The coverage bins defined by the functional model are converted into Conjunction Normal Form (CNF) and then solved together by our proposed simultaneous SAT algorithm PLNSAT to generate stimuli for improving coverage. The basic PLNSAT algorithm is then extended in our second proposed algorithm GPLNSAT, which exploits additional information gleaned from the structure of SystemVerilog covergroups. Compared to generating stimuli separately, the simultaneous SAT approaches can share learned knowledge across each coverage target, thus reducing the overall solving time drastically. Experimental results on a UART circuit and the largest ITC benchmark circuits show that the proposed algorithms can achieve 10.8x speedup on average and outperform state-of-the-art techniques in most of the benchmarks.
  • Item type:Item,
    Reducing Contention in Shared Last-Level Cache for Throughput Processors
    (2014-11-01)
    Kuo, Hsien-Kai
    ;
    Lai, Bo-Cheng Charles
    ;
    Jou, Jing-Yang
    ;
    交大名義發表
    ;
    National Chiao Tung University
    Deploying the Shared Last-Level Cache (SLLC) is an effective way to alleviate the memory bottleneck in modern throughput processors, such as GPGPUs. A commonly used scheduling policy of throughput processors is to render the maximum possible thread-level parallelism. However, this greedy policy usually causes serious cache contention on the SLLC and significantly degrades the system performance. It is therefore a critical performance factor that the thread scheduling of a throughput processor performs a careful trade-off between the thread-level parallelism and cache contention. This article characterizes and analyzes the performance impact of cache contention in the SLLC of throughput processors. Based on the analyses and findings of cache contention and its performance pitfalls, this article formally formulates the aggregate working-set-size-constrained thread scheduling problem that constrains the aggregate working-set size on concurrent threads. With a proof to be NP-hard, this article has integrated a series of algorithms to minimize the cache contention and enhance the overall system performance on GPGPUs. The simulation results on NVIDIA\'s Fermi architecture have shown that the proposed thread scheduling scheme achieves up to 61.6% execution time enhancement over a widely used thread clustering scheme. When compared to the state-of-the-art technique that exploits the data reuse of applications, the improvement on execution time can reach 47.4%. Notably, the execution time improvement of the proposed thread scheduling scheme is only 2.6% from an exhaustive searching scheme.
  • Item type:Item,
    Clock Tree Synthesis Considering Slew Effect on Supply Voltage Variation
    (2014-11-01)
    Wang, Chun-Kai
    ;
    Chang, Yeh-Chi
    ;
    Chen, Hung-Ming
    ;
    Chin, Ching-Yu
    ;
    電子工程學系及電子研究所
    This work tackles a problem of clock power minimization within a skew constraint under supply voltage variation. This problem is defined in the ISPD 2010 benchmark. Unlike mesh and cross link that reduce clock skew uncertainty by multiple driving paths, our focus is on controlling skew uncertainty in the structure of the tree. We observe that slow slew amplifies supply voltage variation, which induces larger path delay variation and skew uncertainty. To obtain the optimality, we formulate a symmetric clock tree synthesis as a mathematical programming problem in which the slew effect is considered by an NLDM-like cell delay variation model. A symmetry-to-asymmetry tree transformation is proposed to further reduce wire loading. Experimental results show that the proposed four methods save up to 20% of clock tree capacitance loading. Beyond controlling slew to suppress supply-voltage-variation-induced skew, we also discuss the strategies of clock tree synthesis under variant variation scenarios and the limitations of the ISPD 2010 benchmark.
  • Item type:Item,
    Extended Instruction Exploration for Multiple-Issue Architectures
    (2014-11-01)
    Wu, I-Wei
    ;
    Shann, Jean Jyh-Jiun
    ;
    Hsu, Wei-Chung
    ;
    Chung, Chung-Ping
    ;
    交大名義發表
    In order to satisfy the growing demand for high-performance computing in modern embedded devices, several architectural and microarchitectural enhancements have been implemented in processor architectures. Extended instruction (EI) is often used for architectural enhancement, while issuing multiple instructions is a common approach for microarchitectural enhancement. The impact of combining both of these approaches in the same design is not well understood. While previous studies have shown that EI can potentially improve performance in some applications on certain multiple-issue architectures, the algorithms used to identify EI for multiple-issue architectures yield only limited performance improvement. This is because not all arithmetic operations are suited for EI for multiple-issue architectures. To explore the full potential of EI for multiple-issue architectures, two important factors need to be considered: (1) the execution performance of an application is dominated by critical (located on the critical path) and highly resource-contentious (i.e., having a high probability of being delayed during execution due to hardware resource limitations) operations, and (2) an operation may become critical and/or highly resource contentious after some operations are added to the EI. This article presents an EI exploration algorithm for multiple-issue architectures that focuses on these two factors. Simulation results show that the proposed algorithm outperforms previously published algorithms.
  • Item type:Item,
    Significant Correlation Pattern Mining in Smart Homes
    (2015-05-01)
    Chen, Yi-Cheng
    ;
    Peng, Wen-Chih
    ;
    Huang, Jiun-Long
    ;
    Lee, Wang-Chien
    ;
    資訊工程學系
    Owing to the great advent of sensor technology, the usage data of appliances in a house can be logged and collected easily today. However, it is a challenge for the residents to visualize how these appliances are used. Thus, mining algorithms are much needed to discover appliance usage patterns. Most previous studies on usage pattern discovery are mainly focused on analyzing the patterns of single appliance rather than mining the usage correlation among appliances. In this article, a novel algorithm, namely Correlation Pattern Miner (CoPMiner), is developed to capture the usage patterns and correlations among appliances probabilistically. CoPMiner also employs four pruning techniques and a statistical model to reduce the search space and filter out insignificant patterns, respectively. Furthermore, the proposed algorithm is applied on a real-world dataset to show the practicability of correlation pattern mining.