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National Science Review 2020年第2期7卷 261-269页

作者： Hao Chi Zhang Tie Jun Cui Yu Luo Jingjing Zhang Jie Xu Pei Hang He Le Peng Zhang State Key Laboratory of Millimeter Waves Southeast University The Photonics Institute and Centre for Optoelectronics and Biophotonics School of Electrical and Electronic Engineering Nanyang Technological University

digital coding and digital modulation are the foundation of modern information science. The combination of digital technology with metamaterials provides a powerful scheme for spatial and temporal controls of electromagnetic waves. Such a technique, however, has thus far been limited to the control of free-space light. Its application to plasmonics to shape subwavelength fields still remains elusive. Here, we report the design and experimental realization of a tunable conformal plasmonic metasurface, which is capable of digitally coding and modulating designer surface plasmons at the deep-subwavelength scale. Based on dynamical switching between two discrete dispersion states in a controlled manner, we achieve digital modulations of both amplitude and phase of surface waves with nearly 100% modulation depth on a single device. Our study not only introduces a new approach for active dispersion engineering, but also constitutes an important step towards the realization of subwavelength integrated plasmonic circuits.

关键词： digital coding digital modulation plasmonics digital metamaterials

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Wireless Communication Based on Information Metasurfaces

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IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES 2021年第3期69卷 1493-1510页

作者： Dai, Jun Yan Tang, Wankai Chen, Ming Zheng Chan, Chi Hou Cheng, Qiang Jin, Shi Cui, Tie Jun Southeast Univ State Key Lab Millimeter Waves Nanjing 210096 Peoples R China City Univ Hong Kong State Key Lab Terahertz & Millimeter Waves Hong Kong 999077 Peoples R China Southeast Univ Natl Mobile Commun Res Lab Nanjing 210096 Peoples R China

Metasurface has great capabilities in tailoring the electromagnetic (EM) waves in a controllable way owing to the carefully designed and arranged subwavelength meta-atoms. In this review paper, the digital version of metasurface, information metasurface (IM), is systematically introduced with its application in wireless communications. IM extends the research scope of metasurface from physics to the information perspective, in which the meta-atoms are represented by using digital codes "0" and "1" to characterize the EM responses. It can achieve programmable controls of EM waves in real time by integrating with the field-programmable gate array (FPGA). On the other hand, the digital coding strategy bridges the physical world and digital world, and further make the metasurface realize direct information processing. With the outstanding advantages, IMs have shown great potentials to bring revolutionary applications in wireless communications. In this article, the basic concepts and principles of IMs and their programmable features are presented first. Then it focuses on the IM-based new architecture transmitters, as well as the IM-integrated wireless networks in more detail. Finally, the current progress and the future directions of IMs in the wireless communications are respectively summarized.

关键词： digital coding information metasurface (IM) metasurface new transmitter architecture smart wireless networks time coding wireless communications

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A Reconfigurable Multifunctional Metasurface for Full-Space Controls of Electromagnetic Waves

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ADVANCED FUNCTIONAL MATERIALS 2021年第25期31卷 2100275-2100275页

作者： Wang, Hai Lin Ma, Hui Feng Chen, Mao Sun, Shi Cui, Tie Jun Southeast Univ Sch Informat Sci & Engn State Key Lab Millimeter Waves Nanjing 210096 Peoples R China

Metasurfaces have attracted much attention in recent years due to their powerful abilities in manipulating electromagnetic (EM) waves. However, most of the previously reported metasurfaces are incapable of real-time control of full-space EM waves, including transmission, reflection, and absorption at the same time. In this paper, a reconfigurable multifunctional metasurface is proposed that demonstrates real-time control of transmission, absorption, and reflection of EM waves, which can be continuously controlled from total transmission to total reflection, and to perfect absorption. In the case of total reflection, the reflected waves can be further manipulated in a programmable way by changing the digital coding sequences via bias voltages. Meanwhile, the metasurface can independently control vertical and horizontal polarized waves in broadband. The reconfigurable functionalities of the metasurface are validated by experiments, which agree very well with numerical simulations. In addition, a potential application of the reconfigurable multifunctional metasurface in a stealth radome is proposed and demonstrated.

关键词： absorption digital coding Metasurface multifunction reconfigurable reflection transmission

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Multiple Block-Size Transform Video coding Using a Subband Structure

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 1991年第1期1卷 59-+页

作者： Chen, Ting-Chung Fleischer, Paul E. Tzou, Kou-Hu BELLCORE Red Bank NJ 07701 USA

The source coding scheme chosen for the experimental research prototype that is currently being designed to demonstrate the digital coding of HDTV for transport within the proposed broadband ISDN (BISDN) fiber optic network is described. The network Interface will be based on a packet based asynchronous transfer mode (ATM) technology, To maximize coding efficiency, run-length coding and variable word length coding are also incorporated in the system. The scheme uses multiple block-size Hadamard transform coding that can be implemented using a set of two-tap filters in a simple subband structure. In spite of the low hardware complexity, which is considered of dominant importance In the overall system performance, high coding efficiency Is obtained. Major features and advantages of this scheme Include the following: 1) Use of a simple, readily integrable basic modular coding block to decompose as well as to reconstruct the signal. 2) Use of the two-tap filler for vertical decomposition results In a structure with minimal line memory requirements. 3) The use of short filters also minimizes response spread In the vicinity of edges which results In excellent rate/distortion coding performance. 4) The resulting image quality has been demonstrated to be quite robust with respect to available bit rate and the structure provides a very flexible means for adjusting the bit rate.

关键词： Network interfaces Video coding Fiber optic networks System performance subband digital coding coding run length encoding

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ADAPTIVE IIR FILTERING AND CHAOTIC DYNAMICS - APPLICATION TO AUDIOFREQUENCY coding

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS 1989年第4期36卷 591-599页

作者： MACCHI, O JAIDANESAIDANE, M ECOLE NATL INGN TUNIS DEPT ELECTROTECH & AUTOMAT CONTROLSYST & TELECOMMUNICAT LABTUNISTUNISIA

The authors study the chaotic dynamic associated with signal processing applications such as digital coding of audiofrequency signals, in which the real-time processing requirements are severe, due to the high speed input flow and low cost/complexity hardware. In the presence of narrowband signals the simple and robust least-mean-square adaptation of the autoregressive moving average predictor used in such systems creates local instabilities, but keeps global stability without external stability constraints, due to the self-stabilization phenomenon. The adaptation speed beta is a bifurcation parameter that changes the predictor's qualitative behavior. The route to chaos is illustrated by beta increasing with typical period doublings and triplings, and the advent of a strange attractor. It is noted that in a real system, the accumulation of computation errors yields pseudochaotic effects and transient chaotic periods. This emphasizes the difference between the mathematical and experimental ideas of chaos.

关键词： arithmetic errors Input Stream chaotic dynamics external stability digital coding Narrowband Infinite impulse response filters strange attractors Adaptive iir filter signal processing chaos

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Design of Acoustic/Elastic Phase Gradient Metasurfaces: Principles, Functional Elements, Tunability, and coding

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APPLIED MECHANICS REVIEWS 2022年第2期74卷 020801-020801页

作者： Chen, A-Li Wang, Yue-Sheng Wang, Yan-Feng Zhou, Hong-Tao Yuan, Si-Min Beijing Jiaotong Univ Dept Mech Beijing 100044 Peoples R China Tianjin Univ Dept Mech Tianjin 300350 Peoples R China

Acoustic/elastic metasurfaces as a kind of two-dimensional metamaterials are of subwavelength thickness and show remarkable ability of acoustic/elastic wave manipulation. They have potential applications in various fields such as acoustic imaging, communications, cloaking, camouflage, vibration/noise control, energy harvesting, and nondestructive testing. In this review, we mainly summarize recent developments in acoustic/elastic phase gradient metasurfaces, including design principles, design of functional elements, wave field manipulation with applications, design of tunable metasurfaces, as well as the emerging digital coding metasurfaces. At last, we outline the future research directions in this field.

关键词： elastic wave acoustic wave metamaterial acoustic metasurface elastic metasurface phase gradient tunability reconfigurability digital coding wavefront manipulation

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Genes and causation

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PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES 2008年第1878期366卷 3001-3015页

作者： Noble, Denis Univ Oxford Dept Physiol Anat & Genet Oxford OX1 3PT England

Relating genotypes to phenotypes is problematic not only owing to the extreme complexity of the interactions between genes, proteins and high-level physiological functions but also because the paradigms for genetic causality in biological systems are seriously confused. This paper examines some of the misconceptions, starting with the changing definitions of a gene, from the cause of phenotype characters to the stretches of DNA. I then assess whether the 'digital' nature of DNA sequences guarantees primacy in causation compared to non-DNA inheritance, whether it is meaningful or useful to refer to genetic programs, and the role of high-level (downward) causation. The metaphors that served us well during the molecular biological phase of recent decades have limited or even misleading impacts in the multilevel world of systems biology. New paradigms are needed if we are to succeed in unravelling multifactorial genetic causation at higher levels of physiological function and so to explain the phenomena that genetics was originally about. Because it can solve the ` genetic differential effect problem', modelling of biological function has an essential role to play in unravelling genetic causation.

关键词： genes genetic causation genetic program digital coding analogue representation cell inheritance

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DSR-RECEIVER FOR THE digital SOUND BROADCASTING VIA THE EUROPEAN SATELLITES TV-SAT/TDF

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IEEE TRANSACTIONS ON CONSUMER ELECTRONICS 1989年第3期35卷 504-511页

作者： KLANK, O ROTTMANN, D Thomson Consumer Electronics Research and Development Laboratories Hanover Germany

The DSR (digital Satellite Radio) concept and its key IC are described. The DSR system delivers excellent audio quality, similar to that of the compact disk. The transmission standard and the equipment for the transmission have been proved in several lengthy field tests using the OTS, Intelsat V, and TDF 1 satellites. The system uses digital coding of the audio signals in conjunction with time-division multiplexing of all channels as well as 4-PSK (phase-shift keying) modulation. The receiving equipment is described in detail.

关键词： Radio broadcasting transfer standards digital coding digital satellite satellites time division multiplexing CONJUNCTION dynamic shear rheometer audio signals

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Engineering particles towards 3D supraballs-based passive cooling via grafting CDs onto colloidal photonic crystals

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Chinese Chemical Letters 2024年第4期35卷 457-463页

作者： Jie Wu Xiaoqing Yu Guoxing Li Su Chen State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringNanjing Tech UniversityNanjing 210009China

Particle engineering has opened the floodgates to material science in both fundamental and application field. However, covalent interactions have not yet been adequately designed in the particle engineering for functional colloidal photonic crystals(CPCs). Herein, we achieved covalent coupling between carboxylrich poly(styrene-acrylic acid)(P(St-AA)) monodispersed colloidal particles and amine-rich carbon dots(CDs) based on an feasible and universal particle engineering strategy. The designed CDs-grafted P(St-AA)monodispersed colloidal particles initiate a hydrogen bond-driven assembly mode and ensure the construction of large-scale crack-free CPCs. Moreover, the CDs equipped with selective broad-band absorption capacity could improve the saturation of structural colors for high-visibility CPCs. Furthermore, an injectable photonic hydrogel(IPH) is developed to design CPC supraball hydrogel via integrating the CDsgrafted P(St-AA) CPC supraballs with supramolecular hydrogel. Combining superior flexibility, sufficient self-healing capacity of supramolecular hydrogel with visual optical information of our CPC supraballs, a cyclically reversible coding and decoding system was developed. Meanwhile, we firstly demonstrated the novel strategy of 3D supraballs-based passive cooling. The designed 3D CPC supraball hydrogel presents nearly full observation angle reflections behavior and excellent water evaporation capacity and achieves3.6 ℃ temperature drops, showing the application advantages in 3D thermal management. This work not only provides a new insight for manipulating optical properties of CPCs, but also demonstrates an easyto-perform platform, as well as indicates the direction for the promising application of CPCs.

关键词： Particle engineering Carbon dots Colloidal photonic crystals Passive cooling digital coding

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MULTILEVEL TERNARY LINE CODES WITH TRELLIS STRUCTURE

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IEE PROCEEDINGS-COMMUNICATIONS 1994年第1期141卷 7-12页

作者： AYGOLU, U PANAYIRCI, E Fac. of Electr. & Electron. Eng. Istanbul Tech. Univ. Turkey

A combination of the two coding techniques given by Imai and Hirakawa (1977) and Pottie and Taylor (1989) is applied to the ternary (+, 0, -) line-code design problem. New ternary coding systems are obtained with reduced decoding complexity and improved error performance, compared with those obtained by the classical Ungerboeck's trellis-coding approach. The decoding complexity for high coding rates is reduced by the proper choice of the punctured convolutional component codes for each partitioning level. A spectral null at zero frequency is obtained by the use of a halfrate unit-memory convolutional encoder at the last partitioning level which selects line codewords with opposite disparities in an alternated fashion so that the running-digital-sum values vary in a finite interval. The effects of the path multiplicity are evaluated by upper bounding the bit error probabilities based on the union-bound approach.

关键词： BASEBAND digital TRANSMISSION digital coding TERNARY LINE CODES TRELLIS STRUCTURES

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