Large Number Of Symbols Research Articles

Intertextual elements of the novel «Masky opadaiut povilno (Masks Fall Slowly)» by Stepan Protsiuk

The works of Stepan Protsiuk are vivid examples of a modernized presentation of the Ukrainian literature classics for a new generation. The article is devoted to the study of intertextual elements in the novel aboutVolodymyr Vynnychenko «Masky opadaiut povilno (Masks Fall Slowly)».Detailing and decoding of intertextual markers serves as an auxiliary factor in understanding the influence of external factors on the protagonist’s life position. The novel attracts attention in the context of contemporarypsychobiographical prose because it contains a large number of symbols and colours. The study reveals and analyses the specifics of Volodymyr Vynnychenko’s artistic portrayal, the complex corpus of his experiences,emotions, secrets of creativity, etc. The artist uses psychologism and deep tragedy of the narrative in a filigree manner, which adds even moresymbolism, metaphor and colour to his novels. «Masky opadaiut povilno(Masks Fall Slowly)» is a subjective perception of the Ukrainian classic, amodelling of his worldview. Stepan Protsiuk tries to show the protagonist not as a messiah of the world, but as a person who also experiences and has a lot of psychological traumas, which only get worse in the future. The chosen literary approach makes it possible to fully reveal the protagonist’s personality and understand the contradictions of the artist’s psychological world.

Interpretation of the Mikhail Lermontov’s Poem “Demon” in the Works of Sergei Parajanov

The article represents a comparative analysis of Mikhail Lermontov’s poem “Demon” and the unrealized script for the film “Demon” by Sergei Parajanov – a completely different view of the familiar text of the poem. Possessing a unique style and taste, Parajanov introduces many new elements and plots which modernize the perception of the poem. The main distinguishing feature of the script is the personality of Tamara. Moving away from the canonical principle of building the text, where the Demon appears in the foreground, Parajanov wants to show the process of soul transformation on behalf of Tamara, while using a large number of symbols.

Joint design of ordered QR precoding and SIC detection for MIMO VLC systems.

Ordered successive interference cancellation (OSIC) detection has been investigated to mitigate the high spatial correlation for multiple-input multiple-output (MIMO) visible light communication (VLC) systems. However, existing OSIC schemes have to perform reordering and matrix inversion for each detected symbol, which may lead to high complexity when a large number of symbols are transmitted. In this work, a joint design of ordered QR decomposition precoding and SIC detection (OQR-SIC) is proposed for MIMO VLC systems. This work jointly investigates OQR precoding and SIC detection to reduce the detection complexity while alleviating spatial correlation issue for MIMO VLC systems. In OQR-SIC, with the upper triangular matrix obtained by QR decomposition, the SIC detector can detect the symbol sequentially without reordering and matrix inversion calculations. To improve the system data rate, we further optimize the ordering of the columns of the channel matrix before QR decomposition and the power allocation of transmitted signals under the constraints of dimming control, total electrical power and reliable SIC detection. Simulation results demonstrate that the proposed OQR-SIC achieves 2 dB and 9.8 dB signal-to-noise ratio gains compared to conventional QR-SIC in 4 × 4 and 9 × 9 MIMO VLC systems, respectively, when the bit error rate is 10-3.

Optimal alphabet for single text compression

A text written using symbols from a given alphabet can be compressed using the Huffman code, which minimizes the length of the encoded text. It is necessary, however, to employ a text-specific codebook, i.e. the symbol-codeword dictionary, to decode the original text. Thus, the compression performance should be evaluated by the full code length, i.e. the length of the encoded text plus the length of the codebook. We studied several alphabets for compressing texts – letters, n-grams of letters, syllables, words, and phrases. If only sufficiently short texts are retained, an alphabet of letters or two-grams of letters is optimal. For the majority of Project Gutenberg texts, the best alphabet (the one that minimizes the full code length) is given by syllables or words, depending on the representation of the codebook. Letter 3 and 4-grams, having on average comparable length to syllables/words, perform noticeably worse than syllables or words. Word 2-grams also are never the best alphabet, on the account of having a very large codebook. We also show that the codebook representation is important – switching from a naive representation to a compact one significantly improves the matters for alphabets with large number of symbols, most notably the words.Thus, meaning-expressing elements of the language (syllables or words) provide the best compression alphabet.

Approximate Message Passing-Based Detection for Asynchronous NOMA

A novel low-complexity multiuser detection scheme is proposed for the asynchronous non-orthogonal multiple access (NOMA). Directly applying the conventional symbol-synchronous detection techniques for the asynchronous NOMA would result in high complexity. For low-complexity, we divide one frame with a large number of symbols into several small blocks. Furthermore, for real-time and low-delay processing under the scenario with a large number of users, each block is independently processed in a parallel way by an approximate message passing-based algorithm. Furthermore, a jointly detection technique is proposed to address the large detection error in the boundary of the blocks, which is induced by the non-interaction between neighbor blocks. Simulation results demonstrate that the proposed detection scheme can achieve near optimal performance with a much lower complexity.

Revised architecture for automatic modulation recognition

Cognition and adaptability is a prominent aspect of Communication Intelligence (COMINT). Automatic Modulation Recognition (AMR) is one such aspect. AMR focuses on identifying modulation technique used at a particular carrier frequency which is got by spectral analysis (SA). The article deals with modulation recognition using feature based approach. This article addresses recognition of modulations both analog and digital sets. Analog modulations considered are Amplitude Modulation (AM), Frequency Modulation (FM), Phase Modulation (PM), Single Side Band Modulation (SSB) and Double Side Band Suppressed Carrier (DSB-SC). Digital modulations considered include Shift Keyings namely Amplitude Shift Keying (ASK), Frequency Shift Keying (FSK), Phase Shift Keying (PSK) with two and four symbols addressed as ASK2, ASK4, FSK2 , FSK4, PSK2, PSK4, respectively. Apart from this Quadrature Amplitude Modulation (QAM) with 8 symbols (QAM8) and Vestigial Side Band Modulation (VSB) stand as contenders for recognition. Its presumed that knowledge of carrier frequency,data rate and bandwidth of information is available with the recognizer; which might be extracted from SA. Analytic signal is built out of the intercepted signal frames and then Instantaneous Amplitude and Phase (IAP) is extracted from the signal frames. Statistical features are extracted from IAP. Intercepted signal frames are constructed using large sampling time, in other way considering large number of symbols in a frame which are used for threshold fixation for decision making. Finally a decision tree is designed and accuracy of the same is tested across varying modulations and noise levels.

A fluctuation theory of communications

(1) In this paper, we investigate fluctuation properties of communication configurations by considering an ensemble of measurements in the space of probabilities. In the limit of a large number of symbols, in a message communicated in a noisy channel, we explore statistical properties of fluctuations by analyzing the critical behavior and geometric invariants at a given pair of true and false probabilities as the model parameters. (2) In the light of the system’s global stability, we examine the long-range statistical correlations, whereby discuss the nature of the underlying interacting/noninteracting domains and associated phase transitions under variations of the model probabilities. (3) Finally, we provide possible directions towards the instrumentation technology and engineering designing, their optimal developments and perspective implications of the intrinsic geometric towards the fluctuation theory understanding of joint configurations, entanglement entropy, generalized measurements, quantum channels in communication systems and simultaneous measurements.

Fast blind channel estimation for space–time block coded MIMO–OFDM systems

Fast blind subspace channel estimation using circular property of the channel matrix is investigated for space–time block coded (STBC) multiple-input multiple-output orthogonal frequency division multiplexing (MIMO–OFDM) systems in this paper. The noise subspace computed from the correlation matrix of received signals requires a large number of symbols to converge in the subspace channel estimation. Using the circular property of the channel matrix, we propose both the cyclic repetition method (CRM) and the forward–backward method (FBM) to generate N times of equivalent signals for each STBC–OFDM symbol, respectively, where N is the size of FFT operation. With these equivalent symbols, the proposed CRM, FBM and CRM–FBM (CFBM) channel estimations can perform very well within a few OFDM symbols. The CRM, FBM and CFBM schemes are applicable to the CP-OFDM, ZP-OFDM and VC-OFDM systems, respectively. The identifiability of the subspace channel estimation is investigated that the channel matrix is determined up to two ambiguity matrices. Computer simulations demonstrate that the CRM-based, FBM-based and CFBM-based channel estimations have better performances than the conventional ones.

Unitary Differential Space-Time-Frequency Codes for MB-OFDM UWB Wireless Communications

In a multiple-input multiple-output (MIMO), multiband orthogonal frequency division multiplexing (MB-OFDM) ultra-wideband (UWB) system, coherent detection requires the transmission of a large number of symbols for channel estimation, thus reducing the bandwidth efficiency. For the first time, this paper proposes unitary differential space-time-frequency codes (DSTFCs) for MB-OFDM UWB communications, which increase the system bandwidth efficiency because no channel state information (CSI) is required. The proposed system would be useful when CSI is unavailable at the receiver, such as when the transmission of multiple channel estimation symbols is impractical or uneconomical. The coding and decoding algorithms for the proposed DSTFCs are then derived for both constant envelope modulation scheme, such as PSK (phase shift keying) and 4QAM (quadrature amplitude modulation), and multi-dimensional modulation scheme, such as DCM (dual carrier modulation). The paper also quantifies for the first time the diversity order of a DSTFC MB-OFDM system. Simulation results show that the application of DSTFCs can significantly improve the bit error performance of conventional differential MB-OFDM system (without MIMO), and even provide much better bit error performance than the conventional coherent MB-OFDM system (without MIMO) at high signal-to-noise ratios.

Low Cost EVM Testing of Wireless RF SoC Front-Ends Using Multitones

Error-vector-magnitude (EVM) is a system level specification that determines the overall modulation quality and exhibits strong correlation to the inherent nonidealities of a radio frequency (RF) system. In production testing, EVM tests incur significant cost due to the large number of symbols required to ensure test quality. In our approach, EVM is decomposed into its deterministic (due to static impairments: IQ mismatch, gain, AM-AM and AM-PM) and random (due to dynamic impairments: VCO phase noise, thermal noise) components. The static impairments are computed from the device under test (DUT) response to an optimized multitone test input. The dynamic impairments are computed using signal processing algorithms from the DUT test response to the same test input. The EVM of the RF system is then derived from the computed static and dynamic impairments, respectively. Experimental results show that significant reduction in test time is possible without compromising EVM test quality.

Probabilistic Model Building Genetic Programming based on Estimation of Bayesian Network

Genetic Programming (GP) is a powerful optimization algorithm, which employs the crossover for genetic operation. Because the crossover operator in GP randomly selects sub-trees, the building blocks may be destroyed by the crossover. Recently, algorithms called PMBGPs (Probabilistic Model Building GP) based on probabilistic techniques have been proposed in order to improve the problem mentioned above. We propose a new PMBGP employing Bayesian network for generating new individuals with a special chromosome called expanded parse tree, which much reduces a number of possible symbols at each node. Although the large number of symbols gives rise to the large conditional probability table and requires a lot of samples to estimate the interactions among nodes, a use of the expanded parse tree overcomes these problems. Computational experiments on two subjects demonstrate that our new PMBGP is much superior to prior probabilistic models.

Mixed-Q linear space-time codes

A new modulation method for linear space-time codes is proposed based on using constellations of different sizes for different symbols. It is shown that the proposed method significantly reduces the complexity of the sphere decoding algorithm. The complexity reduction is more pronounced in high-rate codes, where each code matrix carries a large number of symbols. We also show that the choice of constellation size provides a tradeoff between performance and complexity. Using this, some guidelines for choosing constellation size are presented. As one introduces more constellation disparity in the code, the complexity is further reduced, while the performance loss grows. Typically, a complexity reduction of one to two orders of magnitude can be achieved at the expense of about 3 dB coding gain. We suggest a simple modification in our design to reduce this loss to about 2 dB.

Stroop interference is the result of comparable, not of differential processing speeds of two stimulus dimensions.

On a digit-counting Stroop task, processing of the slower, nonverbal, i.e., number, dimension was slowed further by a large-number set (6 to 9), as compared with a small-number set (1 to 4). In the task, neutral symbols or conflicting digits were arranged on a horizontal line (e.g.,@@, 444) and on two separate sheets. Each sheet contained 120 stimulus arrays. Subjects counted out loud the number of symbols or digits in each array, and their counting times for each sheet were recorded. 23 subjects received the small-number set while 21 received the large-number set. It was found that counting a large number of symbols took significantly longer time (by 162 sec. per 120 stimulus arrays) than counting a small number of symbols. Moreover, interference was nonexistent (2 msec. per stimulus array) when a large number of conflicting digits were counted but was of a typical magnitude (110 msec. per stimulus array) when a small number of conflicting digits were counted. This suggests that Stroop interference is better explained as the result of comparable, not of differential, processing speeds of the two stimulus dimensions. Implications for the cause and the locus of Stroop interference are discussed.

The aerodynamics of hovering insect flight. I. The quasi-steady analysis

The conventional aerodynamic analysis of flapping animal flight invokes the ‘quasisteady assumption’ to reduce a problem in dynamics to a succession of static conditions: it is assumed that the instantaneous forces on a flapping wing are equivalent to those for steady motion at the same instantaneous velocity and angle of attack. The validity of this assumption and the importance of unsteady aerodynamic effects have long been controversial topics. Weis-Fogh tested the assumption for hovering animal flight, where unsteady effects are most pronounced, and concluded that most insects indeed hover according to the principles of quasi-steady aerodynamics. The logical basis for his conclusion is reviewed in this paper, and it is shown that the available evidence remains ambiguous. The aerodynamics of hovering insect flight are re-examined in this series of six papers, and a conclusion opposite to Weis-Fogh’s is tentatively reached. New morphological and kinematic data for a variety of insects are presented in papers II and III, respectively. Paper IV offers an aerodynamic interpretation of the wing kinematics and a discussion on the possible roles of different aerodynamic mechanisms. A generalized vortex theory of hovering flight is derived in paper V, and provides a method of estimating the mean lift, induced power and induced velocity for unsteady as well as quasi-steady flight mechanisms. The new data, aerodynamic mechanisms and vortex theory are all combined in paper VI for an analysis of the lift and power requirements and other mechanical aspects of hovering flight. A large number of symbols are needed for the morphological, kinematic and aerodynamic analyses. Most of them appear in more than one paper of the series, and so a single comprehensive table defining the major symbols from all of the papers is presented at the end of this paper.

Visual Literacy and the Time-Varying Icon

The decreasing cost and increasing capability of computer graphics offers the opportunity to consider a new dynamic, or time-varying, iconic form of written language. Conventional ideographic writing forms, being static, require a very large number of symbols and are hard to learn. The new technology addresses both of these problem areas. Western culture Oriented iconic writing languages already exist, and one, based on American Signing, would really shine if adapted to a dynamic or time-varying presentation form using computer graphics. Some exciting, important, but distant benefits could result from the adoption of such a language form.

Statistical Studies of Printed Devnagari (Hindi) Text

Probability of occurrence of all symbols of Devnagari script in Hindi is computed and the entrony and redundancy of Hindi language is reported. It is found that Hindi is less redundant and more efficient than English The present Devnagari script because of its phonetic nature and a large number of symbols (57) is not very efficient from the view point of telegraphic transmission, hence a modified script having only 42 symbols is hereby proposed and it is hoped that this modified script will be suitable for use by all major Indian languages.

The Punch-marked Coins: A Survival of the Indus Civilization

“Punch-marked coins are the earliest Indian archæo-logical ‘document’ that exists,” wrote Mr. E. H. C. Walsh in 1923 in a thorough study of these interesting remains of Indian proto-historic times. At the time when he wrote his article, very little, if anything, was known of the freshly discovered prehistoric civilization in the Indus Valley, at Harappa and Mohenjo-daro. Even in a more recent publication, in Professor Chakrabortty's numismatic handbook,2 no attempt is made to explain the symbols punched upon these primitive coins, and it still holds good what Mr. Walsh said in 1923: “Until our present sources of information are added to, the significance of the marks on punch-marked coins must remain the subject of speculation and surmise.” The late Mr. W. Theobald's study is an excellent collection of materials, but his explanations might fitly be called “archaic”. Mr. D. R. Bhandarkar has given some very ingenious interpretations of a number of these rūpas. But these interpretations concern only a very few of the large number of symbols.