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Preparation and properties of novel poly(propylene oxide)-block-polylactide-based polyurethane foams

POLYMER ENGINEERING AND SCIENCE 2013年第2期53卷 343-352页

作者： Ma, Yan Yang, Dongmei Shi, Wenpeng Li, Suming Fan, Zhongyong Tu, Jianjun Wang, Wei Fudan Univ Dept Mat Sci Shanghai 200433 Peoples R China China Petr & Chem Corp Shanghai Res Inst Petrochem Technol Shanghai 201208 Peoples R China

A novel degradable flexible polyurethane (PU) foam was prepared by varying the ratio of poly(propylene oxide) (PPO) and triarm poly(propylene oxide)-block-polylactide copolymer (PPO-b-PLA), and was compared with conventional PU foams based on toluene diisocyanate (TDI) and PPO. Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) showed that introducing PLA segments were able to result in a transition from a microphase separated state to a microphase mixed state and improve the microphase mixing. The changes in structure and domain size distribution associated with this transition were found to have led to enhanced mechanical properties such as the tensile strength, the elongation at break, and the rebound resilience for the PU foams containing PLA segments. Furthermore, it was observed that the network structure was destroyed by hydrolytic degradation in alkali solution (10 wt%/vol%) at 80 degrees C for 50 h, and that as the PLA content increased, the degradation rate of PU foams enhanced. POLYM. ENG. SCI., 2013. (c) 2012 Society of Plastics Engineers

关键词： programmable logic arrays Polypropylenes Fourier transform infrared spectroscopy MICROPHASE Polyphenylene oxides polyurethane foam Differential scanning calorimetry rebound Plutonium Elongation at break

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ANALYSIS OF TESTABLE PLA DESIGNS

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IEEE DESIGN & TEST OF COMPUTERS 1988年第4期5卷 14-28页

作者： ZHU, XA BREUER, MA UNIV SO CALIF DEPT ELECT ENGNLOS ANGELESCA 90089 UNIV TEXAS DEPT ELECT & COMP ENGNAUSTINTX 78712

A framework is presented for evaluating methods of testing programmable logic arrays (PLAs), and the attributes of 25 test design methodologies are tabulated. PLA testing problems are first examined, and several test-generation algorithms are briefly described. Techniques for designing testable designs are examined, namely, special coding, parity checking, signature analysis, divide and conquer, and fully testable PLAs. The attributes that make a good testable design are then discussed. They fall into four categories: (1) testability characteristics; (2) effect on original design; (3) requirements of the application environment; and (4) design costs, i.e. how difficult it is to implement the technique.

关键词： programmable logic arrays logic testing Hardware logic design Design methodology logic arrays System testing Time division multiplexing Design optimization Area measurement

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A BEST-FIRST SEARCH ALGORITHM FOR OPTIMAL PLA FOLDING

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IEEE TRANSACTIONS ON COMPUTER-AIDED DESIGN OF INTEGRATED CIRCUITS AND SYSTEMS 1986年第3期5卷 433-442页

作者： HWANG, SY DUTTON, RW BLANK, T Department of Electrical Engineering University of Stanford Stanford CA USA

In this paper we propose a new algorithm for optimal PLA folding based on a graph theoretic formulation. An efficient best-first search (BFS) algorithm is presented which finds a near-optimal PLA folding. The proposed algorithm first constructs the longest paths on the associated disjoint graph generated from the PLA personality matrix, and then extracts the ordered folding sets from the constructed paths. The algorithm is shown to be effective for most test cases.

关键词： programmable logic arrays Testing logic arrays Sun Silicon Heuristic algorithms Computational complexity Terminology Drives Design automation

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MASTERIMAGE APPROACH TO VLSI DESIGN

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COMPUTER 1983年第12期16卷 18-25页

作者： DONZE, RL SPORZYNSKI, G IBM CORP POB AESSEX JUNCTIONVT 05452 IBM CORP ROCHESTERMN 55901

The rapid development of semiconductor technology and the increasing complexity of VLSI chips have prompted a wide range of design approaches. Among them is one called the masterimage method, which is somewhere between the unconstrained approach, in which the designer has essentially total freedom, and the constrained approach, typified by the gate array. The masterimage design methodology, which has been implemented on an extension of IBM's engineering design system, can design chips with up to ten thousand equivalent two-way NOR gates. A key feature of the EDS extension is its ability to design chips with macros, or blocks of circuitry such as RAMs and PLAs. The EDS provides for logic simulation, test-pattern generation, description of the chip image (layout) and circuits, and automated placement and interconnection of circuits and macros. A delay calculator/optimizer insulates logic design from performance considerations. The emphasis in this article is on the overall solution to the problem of designing complex VLSI chips. Details of the technology or algorithms are discussed only when needed to illustrate the system's capabilities.

关键词： Very large scale integration Shape measurement Semiconductor device measurement Design methodology logic testing Circuit testing Manufacturing processes Design engineering Systems engineering and theory programmable logic arrays

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2 NP-HARD INTERCHANGEABLE TERMINAL PROBLEMS

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IEEE TRANSACTIONS ON COMPUTER-AIDED DESIGN OF INTEGRATED CIRCUITS AND SYSTEMS 1988年第4期7卷 467-472页

作者： SAHNI, S WU, SY Computer Science Department University of Minnesota Minneapolis MN USA

Two subproblems that arise when routing channels with interchangeable terminals are shown to be NP-hard. These problems are: (1) determining whether there is a net-to-terminal assignment that results in an acyclic vertical and constraint graph and (2) for instances with acyclic vertical constraint graphs, obtaining net-to-terminal assignments for which the length of the longest path in the vertical constraint graph is minimum.< >

关键词： Routing programmable logic arrays programmable logic devices Computer science NP-complete problem Design automation

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A Survey of Physical-Layer Authentication in Wireless Communications

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IEEE COMMUNICATIONS SURVEYS AND TUTORIALS 2021年第1期23卷 282-310页

作者： Xie, Ning Li, Zhuoyuan Tan, Haijun Shenzhen Univ Coll Elect & Informat Engn Guangdong Key Lab Intelligent Informat Proc Shenzhen 518060 Peoples R China Shenzhen Univ Coll Elect & Informat Engn Shenzhen Key Lab Media Secur Shenzhen 518060 Peoples R China

Authentication is an important issue in wireless communications because the open nature of the wireless medium provides more security vulnerabilities. Recently, Physical-Layer Authentication (PLA) attracts many research interests because it provides information-theory security and low complexity. Although many researchers focus on the PLA and exploit its potential in enhancing wireless security, the literature is surprisingly sparse with no comprehensive overview of the state-of-the-art PLA and the key fundamentals involved. Thus, this article provides a detailed survey of features and techniques that can be used in the PLA. We categorize the existing PLA schemes into two categories: passive and active schemes. In the passive schemes, a receiver authenticates the transmitter based on the physical-layer features of the received signals. We further divide the passive schemes into two sub-categories: device-based features and channel-based features. In the active schemes, a transmitter generates a tag based on a secret key and embeds it into a source message. Then, a receiver authenticates the transmitter based on the tag whether it exists in the received signal. We further divide active schemes into two sub-categories: non-covert schemes and covert schemes. Moreover, we also provide some future research directions.

关键词： programmable logic arrays Authentication Receivers Wireless communication Cryptography Signal to noise ratio Interference Physical-layer authentication passive active robustness covertness security

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One-pot copolymerization of epoxides/carbon dioxide and lactide using a ternary catalyst system

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CATALYSIS SCIENCE & TECHNOLOGY 2018年第24期8卷 6452-6457页

作者： Li, Xiang Hu, Chenyang Pang, Xuan Duan, Ranlong Chen, Xuesi Chinese Acad Sci Changchun Inst Appl Chem Key Lab Polymer Ecomat 5625 Renmin St Changchun 130022 Jilin Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China

Poly(propylene carbonate) (PPC) and polylactide (PLA), two major types of biodegradable polymers, are produced by the cooperative ring-opening polymerization (coROP) of propylene oxide and CO2 and by the ring-opening polymerization (ROP) of lactide. Because of the incompatibility between coROP and ROP, only simple copolymers of PPC and PLA with up to three blocks have been synthesized. A hybrid of these two polymers would produce a new family of polymers. The new polymers would be regarded as promising biodegradable materials because they would combine the desirable properties of PPC and PLA. Here, we report the synthesis of a PLA/PPC multiblock copolymer using a novel ternary catalytic system that proceeds via an intermolecular chain transfer mechanism. The resultant polymer, which is 100% biodegradable, shows enhanced thermal properties stemming from the incorporation of the PPC units. The broad applicability was further confirmed by extension to other monomers and catalysts.

关键词： incompatibility Retinopathy of Prematurity copolymerization New families PPCS gene biodegradable polymer Ternary lactic acid Catalysts propylene oxide programmable logic arrays Thermal properties

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EPLA-DSTree: Extending Piecewise Linear Approximation on a Dynamic Segmentation Tree Index in Sensor-Cloud Systems

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IEEE ACCESS 2021年 9卷 123742-123753页

作者： Xie, Bin Li, Qiuhong Wang, Yang Wang, Peng Nanjing Univ Sci & Technol Sch Comp Sci & Engn Nanjing 210094 Peoples R China Shanghai Chang Jiang Intelligent Data Technol Co Shanghai 201600 Peoples R China Fudan Univ Comp Coll Shanghai 200433 Peoples R China

In sensor-cloud applications, a huge amount of time series are generated. Efficient similarity search approaches are necessary for processing these sensor time series data. Concerning of time series search, whole matching similarity search and subsequence similarity search are two main research focuses. In this paper, we study the whole matching similarity search problem. We propose EPLA-DSTree, which extends piecewise linear approximation on a dynamic segmentation tree index for whole matching on time series. Compared with DSTree, EPLA-DSTree improves data locality of nodes by a better time series representation. EPLA-DSTree has a tighter lower bound for nodes which leads to a better query performance. Experiments show that it has a less index building time and a better query performance. To meet the requirements of sensor-cloud applications, we present an parallel EPLA-DSTree on MapReduce, which is a popular cloud programming model.

关键词： Time series analysis programmable logic arrays Indexes Piecewise linear approximation Cloud computing Upper bound Search methods Time series search sensor cloud index

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Development of a FPGA Based Real-Time Power Analysis and Control for Distributed Generation Interface

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IEEE TRANSACTIONS ON POWER SYSTEMS 2012年第3期27卷 1343-1353页

作者： Cardenas, Alben Guzman, Cristina Agbossou, Kodjo Univ Quebec Trois Rivieres Hydrogen Res Inst Trois Rivieres PQ G9A 5H7 Canada Univ Quebec Trois Rivieres Dept Genie Elect & Genie Informat Trois Rivieres PQ G9A 5H7 Canada

Energy coming from renewable sources has become very important nowadays, mainly because of their negligible contribution to greenhouse gas generation. A problem that then arises is how to integrate these new sources into a traditional power grid, in such a manner as to maximize the efficiency and reliability of this new distributed generation (DG) system. The hardware to do that is generally a voltage source inverter (VSI) that supplies a common load, as in single-phase residential and commercial applications. The optimizing process requires, of course, the usual power analysis. This paper presents the development and the experimental evaluation of a power control system for a single-phase grid-connected VSI including the power analysis using as processor for the control implementation a field-programmable gate array (FPGA) circuit. New hardware structures of adaptive linear neural networks (ADALINE) allow the implementation of power control algorithms and have also permitted the real-time analysis of the high-order harmonics without increasing the implementation area of the FPGA circuit. These features are ideal for novel DG power electronics interfaces that could be used not only for active power dispatch but also for harmonics and reactive power compensation. Simulation and experimental results of the proposed fixed and variable frequency schemes are included to confirm their validity.

关键词： Artificial neural networks (ANNs) distributed power generation harmonic analysis programmable logic arrays power measurement total harmonic distortion

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Seeking solutions in configurable computing

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COMPUTER 1997年第12期30卷 38-+页

作者： MangioneSmith, WH Hutchings, B Andrews, D DeHon, A Ebeling, C Hartenstein, R Mencer, O Morris, J Palem, K Prasanna, VK Spaanenburg, HAE BRIGHAM YOUNG UNIV PROVO UT 84602 USA UNIV ARKANSAS FAYETTEVILLE AR 72701 USA UNIV CALIF BERKELEY BERKELEY CA 94720 USA UNIV WASHINGTON SEATTLE WA 98195 USA UNIV KAISERSLAUTERN D-67663 KAISERSLAUTERN GERMANY STANFORD UNIV STANFORD CA 94305 USA UNIV WESTERN AUSTRALIA NEDLANDS WA 6009 AUSTRALIA NYU COURANT INST MATH SCI NEW YORK NY USA UNIV SO CALIF LOS ANGELES CA 90089 USA SANDERS ADV TECHNOL DIV SIGNAL PROC CTR EXCELLENCE NASHUA NH USA

Configurable computing systems combine programmable hardware with programmable processors to capitalize on the strengths of hardware and software. They have the potential for achieving high performance for a range of applications, including image filtering, convolution, morphology, feature extraction, and object tracking. Researchers have developed prototype systems that achieve performance an order of magnitude higher than more conventional approaches. However, realizing this potential outside of the laboratory has proven difficult. No system to date has yet proven attractive or competitive enough to establish a commercial presence. Ample opportunity exists for work in a broad range of areas. Not surprisingly, many of the most pressing needs can be lumped into the category of FPGA-related technology, because so many configurable computing systems are based on FPGAs.

关键词： Hardware Application software Field programmable gate arrays Prototypes Circuits Switches programmable logic arrays logic arrays Bandwidth High performance computing

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