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FAST STRUCTURED DESIGN OF VLSI CIRCUITS

IEEE TRANSACTIONS ON EDUCATION 1989年第3期32卷 246-258页

作者： SMITH, KF GU, J Department of Computer Science University of Utah Salt Lake UT USA

It is suggested that a structured, user-friendly, cost-effective tool for rapid implementation of VLSI circuits which encourages students to participate directly in research projects is the key component in digital integrated circuit (IC) education. The authors introduce their VLSI education activities, with emphasis on the presentation of path-programmable logic (PPL) design methodology as well as a short description of a representative student project. Students using PPL are able to implement MOS or GaAs VLSI circuits with several thousand to over 100000 transistors in a few weeks. They have designed and built numerous VLSI architectures and computer systems which play an influential role in various research areas.< >

关键词： Very large scale integration Digital integrated circuits Computer science education Hardware Computer architecture Circuit testing Computer vision Educational programs logic design programmable logic arrays

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High Molecular Weight Poly (L-lactic Acid) Clay Nanocomposites Via Solid-State Polymerization

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POLYMER COMPOSITES 2011年第3期32卷 497-509页

作者： Katiyar, Vimal Nanavati, Hemant Indian Inst Technol Dept Chem Engn Bombay 400076 Maharashtra India

We propose here, a novel technique to synthesize high molecular weight (MW) poly (L-lactic acid)-clay nanocomposite (PLACN), via solid state polymerization (SSP). We synthesize prepolymer of PLACN (pre-PLACN) from both, L-lactic acid and L-lactide, as starting materials. Synthesis of pre-PLACN from L-lactic acid is carried out via in situ melt polycondensation (MP) of L-lactic acid oligomer, followed by SSP, to achieve high MW PLACN (M-w similar to 138,000 Da). In case of L-lactide as the starting material, we prepare L-lactide-clay intercalated mixture which yields moderate MW pre-PLACN during subsequent ring opening polymerization (ROP). Interestingly, ROP is performed by using hydroxyl functionalized ternary catalyst system (L-lactide Sn(II) octoate oligo (L-lactic acid) complex), which provides the terminal hydroxyl end-groups, required for step-growth SSP. Pre-PLACN MW is now increased to M-w similar to 127,000 Da, by the subsequent SSP process. H-1 NMR analyses confirm that these end-groups, are indeed consumed during SSP. During SSP, the PLACN also achieves up to 90% crystallinity, which may be due to the synchronization of the slow step-growth SSP of poly(L-lactic acid) (PLA) with the crystallization kinetics. Optical purity of PLACNs is similar to that of neat PLA, whereas the thermal stability of PLACNs is significantly superior. As evidenced by wide-angle X-ray scattering/small-angle X-ray scattering analyses and in line with the literature, both, intercalated and exfoliated PLACN morphologies, have been synthesized, by suitable selection of clays. We also verify the correlation between the PLA semicrystalline morphology and the PLACN morphology, which is consistent with those of PLACN synthesized by other techniques. POLYM. COMPOS., 32:497-509,2011. (C) 2011 Society of Plastics Engineers

关键词： Retinopathy of Prematurity poly-L-lactic acid programmable logic arrays solid state clays High molecular weight L-Lactic Acid STEP GROWTH

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New Attacks on the GPRS Encryption Algorithms GEA-1 and GEA-2

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IEEE TRANSACTIONS ON INFORMATION FORENSICS AND SECURITY 2022年 17卷 2878-2889页

作者： Ding, Lin Wu, Zheng Wang, Xinhai Guan, Ziyu Li, Mingjin PLA SSF Informat Engn Univ Zhengzhou 450001 Peoples R China

GEA-1 and its successor GEA-2 are two stream ciphers, designed to protect against eavesdropping General Packet Radio Service (GPRS) between the phone and the base station. They were widely used for GPRS encryption in the late 1990s and during the 2000s, and are surprisingly still supported in a range of current mobile phones. In this paper, new key recovery attacks on GEA-1 and GEA-2 are proposed by combining with the time-memory trade-off technique. The new attacks significantly reduce the time and memory costs of the previous attacks on GEA-1, and show that GEA-1 only offers 32-bit (out of 64) security. Furthermore, the slide properties of GEA-1 and GEA-2 are first found and used to explore practical related key attacks. The results show that GEA-1 and GEA-2 can be broken on a common PC within about 0.81 and 6.2 seconds in the multiple related key setting, respectively. Finally, an improved variant of GEA-2 called GEA-2a is proposed. The reasons for making the changes from GEA-2 are explained in detail, which indicates that GEA-2a has significantly better resistance than GEA-2 against all known attacks and can offer 64-bit security.

关键词： Ciphers Security Encryption Time complexity programmable logic arrays Complexity theory Resistance Cryptanalysis GEA-1 GEA-2 stream cipher general packet radio service

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A KNOWLEDGE-BASED SYSTEM FOR SELECTING TEST METHODOLOGIES

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IEEE DESIGN & TEST OF COMPUTERS 1988年第5期5卷 41-59页

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

A prototype knowledge-based system that helps select test methodologies for a particular type of logic structure is described. The system, called TDES, (testable design expert system), is a subsystem of Adam, an advanced design automation system. The system is being used to test programmable logic arrays, but its architecture is applicable to other types of structures such as RAMs, ROMs, and other combinational logic. It uses a divide-and-conquer (partitioning) strategy and works interactively with a user as an intelligent consultant and assistant.

关键词： Knowledge based systems System testing Circuit testing logic testing Time division multiplexing Kernel Automatic testing Design automation programmable logic arrays Very large scale integration

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Blind Physical-Layer Authentication Based on Composite Radio Sample Characteristics

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IEEE TRANSACTIONS ON COMMUNICATIONS 2022年第10期70卷 6790-6803页

作者： Li, Dongming Yang, Xuan Zhou, Fuhui Wang, Dawei Al-Dhahir, Naofal Southeast Univ Sch Cyber Sci & Engn Nanjing 211189 Peoples R China Nanjing Univ Aeronaut & Astronaut Coll Elect & Informat Engn Nanjing 210000 Peoples R China Northwestern Polytech Univ Sch Elect & Informat Xian 710072 Peoples R China Univ Texas Dallas Dept Elect & Comp Engn Richardson TX 75080 USA

The promising physical-layer authentication (PLA) scheme enjoys low computational complexity and provides a lightweight solution for the wireless transmission security problem. However, the ideal but impractical assumptions are made on the priori knowledge in the traditional PLA schemes, which fail because the priori knowledge can be interfered by the impersonation attacks. Hence, a blind PLA scheme featured by the composite radio sample characteristics, active monitoring slots, and blind hypotheses tests is proposed in this paper. In particular, the intrinsic location-specific channel response integrated with the transmitter-specific signal knowledge is sampled during the active monitoring slots and is used to conduct minimum error (ME) and Neyman-Pearson (NP) hypothesis tests. The authentication reliability is enhanced significantly by jointly using the ME and NP criteria. For both the stationary and the non-stationary signal cases, our theoretical analysis shows that the temporal channel variations, the spatial channel correlations and the spectral bandwidth contribute to improve the authentication reliability. Our simulation results not only demonstrate the effectiveness of the proposed PLA scheme, but also indicate the possible scenarios in which ME outperforms NP, and NP outperforms ME.

关键词： Authentication programmable logic arrays Security Wireless communication Training Monitoring Maximum likelihood estimation Physical-layer security hypothesis test blind authentication impersonation attack Neyman-Pearson

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Efficient Simulation of Large Irregular arrays on a Finite Ground Plane

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IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 2020年第4期68卷 2753-2764页

作者： Cavillot, Jean Tihon, Denis Mesa, Francisco Acedo, Eloy de Lera Craeye, Christophe Catholic Univ Louvain ICTEAM B-1348 Louvain La Neuve Belgium Univ Cambridge Cavendish Lab Cambridge CB3 0HE England Univ Seville Dept Fis Aplicada 1 E-41012 Seville Spain

An efficient method is presented to take into account the radiation pattern deformation due to the presence of a finite ground plane lying under an antenna array and above a layered dielectric medium. The interactions between the antennas and the ground plane are computed using two main algorithms: on one hand, the near-field interactions are carried out using inhomogeneous plane waves, and on the other hand, a new formulation based on an analytical Hankel transform is derived to handle the intermediate-field interactions. This formulation expresses the electric field as a finite series of Hankel functions and associated Anger-Weber functions. The method is validated here for the second version of the square kilometer array (SKA) log-periodic Antenna (SKALA2) and then applied to an SKA low-frequency station (SKA1-LOW).

关键词： Antenna arrays Antenna radiation patterns Nonhomogeneous media Method of moments Mathematical model programmable logic arrays Anger-Weber functions FEKO Green's function inhomogeneous plane waves method of moments (MoM) square kilometer array (SKA)

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Aliphatic polyester blends based upon poly(lactic acid) and oligomeric poly(hexamethylene succinate)

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JOURNAL OF MACROMOLECULAR SCIENCE-PURE AND APPLIED CHEMISTRY 1997年第11期A34卷 2165-2175页

作者： Lostocco, MR Huang, SJ [a] Polymers and Biosystems Group Institute of Materials Science University of Connecticut Storrs CT

In an attempt to gain a degree of control over the mechanical and degradation properties of poly(lactic acid) [PLA], large-scale efforts are underway to alter the phase morphology of PLA through chemical and physical modification Consistent with this theme, our work aims to adjust the molecular architecture of highly amorphous PLA with an increasing concentration of hydroxy-terminated oligomeric poly (hexamethylene succinate) [PHS]. Gel-permeation chromatography (GPC) verifies the enhanced presence of PHS in the blends with a concomitant reduction in number-average molecular weight as the weight fraction of PHS is raised from 0.10 to 0.40. Differential scanning calorimetry (DSC) indicates amorphous phase compatibility between PHS and PLA at weight compositions of 10/90 and 20/80. However, as the amount of PHS approaches 30 and 40 wt%, the PHS exhibits the ability to crystallize independently from the induced PLA crystalline phase. Dynamic mechanical thermal analysis (DMTA) illustrates variable behavior of the materials under tension as a consequence of structural alterations generated by the oligoester. Finally, preliminary results suggest that these alterations may suppress the hydrolytic degradation of PLA.

关键词： POLY(TETRAMETHYLENE SUCCINATE) POLYLACTIDE SCREWS DEGRADATION MORPHOLOGY POLYMERS BEHAVIOR programmable logic arrays aliphatic polyester Succinates GLI3 wt Allele Blends PHASE MORPHOLOGY poly(lactic acid)

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Pathways for Improving the Photovoltaic Efficiency of Porphyrin and Phosphorene Antidot Lattice Nanocomposites: An Insight from a Theoretical Study

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JOURNAL OF PHYSICAL CHEMISTRY C 2019年第9期123卷 5303-5311页

作者： Kar, Moumita Sarkar, Ritabrata Pal, Sougata Sarkar, Pranab Visva Bharati Univ Dept Chem Santini Ketan 731235 W Bengal India Univ Gour Banga Dept Chem Malda 732103 India

The porosity of a newly synthesized phosphorene antidot lattice (PAL) is promising for encapsulating the porphyrin molecule and thus shows a versatile route to fabricate porphyrin/PAL nanocomposites. We herein explored the photovoltaic performance of a tetraphenylporphyrin (TPP)/PAL composite system. Interestingly, TPP/PAL composites show type-II staggered band alignment where a conduction band resides on TPP and a valence band resides on PAL. However, the driving force for hole transfer to PAL from TPP is very small (similar to 0.02 eV), implying faster charge recombination inside the TPP itself. To overcome the unpleasant situation, we adopted a substitution strategy at TPP and PAL components. As porphyrins are effective photosensitizers due to the pi-conjugated electronic structure, we attached an electron-donating group (-NH2) to the TPP moiety and an electron-withdrawing group (-CN) at the edge of PAL. The composites show a high photovoltaic performance of up to 13.5%, making them competitive with other two-dimensional heterostructural solar cells. Interestingly, if the starting material is TiO-TPP instead of TPP, then one may achieve the intended type-II band alignment and open up a new route to improve the efficiency without functionalizing the TPP or PAL.

关键词： LRIT1 gene PHOTOVOLTAIC SHCBP1 gene programmable logic arrays Theoretical Study porphyrins Pathway Thiamine Pyrophosphate

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Synthesis and water sorption of standard and end-capped polylactides: the effect of morphology

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POLYMER CHEMISTRY 2012年第3期3卷 718-726页

作者： Koo, Donghun Du, An Palmese, Giuseppe R. Cairncross, Richard A. Drexel Univ Dept Chem & Biol Engn Philadelphia PA 19104 USA

This paper investigates the relationship between morphology and water sorption in polylactide (PLA) films. Standard PLAs and palmityl initiated end-capped PLAs were synthesized with various terminating end groups such as hydroxyl, acetoxy, and palmitoyl end groups. Results from wide angle X-ray scattering and atomic force microscopy were correlated with different sorption phenomena, suggesting that crystallization and microphase separation between amorphous PLA and hydrophobic end-group-rich domains reduced water sorption in PLA. The morphological changes were affected by end-group composition, molecular weight and stereoisomerism.

关键词： programmable logic arrays synthesis END-CAPPING WIDE ANGLE X-RAY SCATTERING Polylactides stereoisomerism Microphase separation Pellicular Water

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EFFICIENT STATE REDUCTION METHODS FOR PLA-BASED SEQUENTIAL-CIRCUITS

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IEE PROCEEDINGS-E COMPUTERS AND DIGITAL TECHNIQUES 1992年第6期139卷 491-500页

作者： AVEDILLO, MJ QUINTANA, JM HUERTAS, JL Departamento de Diseño Analógico Centro Nacional de Microelectrónica Sevilla Spain

Experiences with heuristics for the state reduction of finite-state machines are presented and two new heuristic algorithms described in detail. Results on machines from the literature and from the MCNC benchmark set are shown. The area of the PLA implemention of the combinational component and the design time are used as figures of merit. The comparison of such parameters, when the state reduction step is included in the design process and when it is not, suggests that fast state-reduction heuristics should be implemented within FSM automatic synthesis systems.

关键词： FINITE SEQUENTIAL MACHINES programmable logic arrays STATE MINIMIZATION

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