In the classical lossy source coding problem, one encodes long blocks of source symbols that enables the distortion to approach the ultimate Shannon limit. Such a blockcoding approach introduces ...large delays, which is undesirable in many delay-sensitive applications. We consider the zero-delay case, where the goal is to encode and decode a finite-alphabet Markov source without any delay. It has been shown that this problem lends itself to stochastic control techniques, which lead to existence, structural, and general structural approximation results. However, these techniques so far have only resulted in computationally prohibitive algorithmic implementations for code design. To address this problem, we present a practically implementable reinforcement learning design algorithm and rigorously prove its asymptotic optimality. In particular, we show that a quantized Q-learning algorithm can be used to obtain a near-optimal coding policy for this problem. The proof builds on recent results on quantized Q-learning for weakly Feller controlled Markov chains whose application necessitates the development of supporting technical results on regularity and stability properties, and relating the optimal solutions for discounted and average cost infinite horizon criteria problems. These theoretical results are supported by simulations.
The purpose of this article is to prove the ineffectiveness of the financial supervision measures of the Democratic Republic of Congo in commercial transactions or exchanges in the eastern part of ...the ITURI Province. Indeed, the absence of one the symbols of sovereignty in the circulation of Congolese currency (Congolese Franc) in this part of the country, leads to the low percentage of use of its currency by its population. As a result, eighty-seven point five percent use Ugandan currency (shilling) as opposed to eleven percent of the currency of the Democratic Republic of Congo according to the results of the field's surveys. Consequently, it is imperative that the government of the Democratic Republic of Congo make its population aware of the merits of valuing their currency, which is one of the symbols of a country's sovereignty. The government will strive to implement control structures for the effective use of its currency. It will undertake to set up production units to better sell these quality products in its currency at affordable prices. Ultimately, the implementation of mechanisms to control and industrialize manufactured products at lower cost could benefit and advantage the Democratic Republic of Congo in the implementation of free trade area.
State symbols can be considered an important element of the existence of every independent state. State symbols perform important functions both internally and externally (in relation to other ...countries and international communities). State symbols developed and changed along with the development of the given state and society. The article deals with the development of state symbols in five Central European countries, namely the Czech Republic, Slovakia, Poland, Hungary and Slovenia. The authors analyze the individual state symbols of these states, their development and meaning, at the same time pointing out differences, but also similarities within these European states and their often common history.
The spreadsheet software Microsoft Excel, when used with default settings, is known to convert gene names to dates and floating-point numbers. A programmatic scan of leading genomics journals reveals ...that approximately one-fifth of papers with supplementary Excel gene lists contain erroneous gene name conversions.
Personalized mappings become popular among the public with the support of data diversity and device diversity. To develop personalized maps, constructing map symbols through automated ways is ...beneficial. The formal representation of map symbols (i.e., expressing map symbols by mathematical operators) is fundamental to the automated construction of map symbols. A previous study to evaluate the feasibility of structures of Chinese characters for representing map symbols shows that 77.5% of map symbols can be represented by them, although there are imperfections in some cases. It means that: (1) the other 22.5% of symbols should be formally represented by other mathematical solutions, and (2) those imperfect cases should be made perfect through some modification or refinements. In this study, we solve the representation problems of these two types of map symbols (i.e., the map symbol did not or imperfectly fit the structures of Chinese characters) by employing additional basic operators and proposing some metric and color modifications. To validate these proposed solutions, experiments have been carried out by using eight sets of symbols that are publicly available (e.g., Google Icons). The results indicated that almost all the map symbols can be formally represented with additional operators and metric and color modifications. The percentages of map symbols that did not fit structures of Chinese characters solved by these operators and modifications are 2.4% and 20.1%, respectively. The percentages of map symbols that imperfectly fit them solved by these operators and modifications are 8.7% and 8%, respectively. This work could not only enrich cartographic theory but also prompt the mathematization of map symbol construction.
This study explored performance on expressive and receptive graphic symbol tasks and spoken comprehension by individuals who use augmentative and alternative communication (AAC) as well as the ...relationship of performance with participants' skills and characteristics. Participants were 19 children and youth (aged 5- to 18-years-old) who used aided communication. Four experimental tasks were administered, with either speech or symbols as input (stimuli) and symbols or choice from an array of pictures as output (response). Symbols were not accompanied by written or spoken labels in the tasks. Measures of receptive vocabulary, receptive syntax, memory, and visual cognitive skills as well as information regarding participant characteristics were collected. There were strong relationships among all experimental tasks. Cluster analysis revealed different response patterns that may suggest a progression in expressive and receptive performance with graphic symbol sentences. Individual differences in receptive language, particularly receptive syntax, were related to task performance. The findings suggest that different ways of experiencing symbols, in addition to spoken comprehension of the sentences and receptive spoken language more generally, may contribute to expressive graphic symbol sentences. Performance on receptive symbol tasks may uncover a level of facility with the graphic-symbol modality not observed through expressive symbol use in communicative situations.
The transmission characterized by ultra reliable and low latency requirements presents a significant challenge in the future networks, leading to an increasing interest in powerful short channel ...codes. In this letter, we consider the concatenation of a tail-biting convolutional code (TBCC) with an index modulation (IM) mapper as a promising scheme. Bit-interleaved coded modulation with iterative decoding (BICM-ID) is employed in the TBCC-IM and a modified IM mapping arrangement is developed to improve the error-correction performance. Experimental results show that the implemented TBCC-IM scheme can nearly approach the random coding union (RCU) bound with reasonable complexity.
We theoretically and experimentally compare the optical and mechanical properties of reduced coating diameter Single-Mode Fibers (SMFs) with either dual-coating or single-coating systems and standard ...125μm cladding diameter. A G.657.A2 trench-assisted step-index SMF with a colored single coating of 170μm diameter and Young's modulus of 900MPa is fabricated. The micro-bend-losses are higher than those of a 165μm dual-coating diameter fiber but still at acceptable levels for most cable and connectivity applications, and the tensile strength, coating strip force, and proof-test break rate are improved. Such a single-coating approach can lead to 150μm coating diameter SMFs that meet the optical and mechanical requirements of the industry, when the dual-coating approach reaches its limits.
Massive multiple-input multiple-output (MIMO) is a promising technology that offers high quality of services (QoS) for current and future communication systems. However, deploying a large number of ...antennas in massive MIMO systems increases the detection complexity. To address this challenge, this paper introduces a novel symbol detection scheme called DeepEigen-Tabu, which combines the deep learning-based eigen network (DeepEigNet) with probabilistic Tabu search (P-TS). In the proposed scheme, DeepEigNet, a deep neural network, is constructed to utilize the eigenvalues and eigenvectors of the channel matrix to provide approximate symbol estimates. Subsequently, these estimates serve as the initialization and are prioritized according to their probabilities of correction to support the P-TS. Furthermore, the P-TS integrates an early stopping mechanism based on correction probabilities to eliminate unnecessary iterations during the Tabu search process. Finally, computer simulations and complexity analysis demonstrate that the proposed DeepEigen-Tabu scheme outperforms existing methods while maintaining lower complexity. For instance, in communication scenarios with both transmit and receive antennas set to 16, the proposed DeepEigen-Tabu method demonstrates savings of approximately signal-to-noise ratio (SNR) 0.8 dB at bit error rate (BER) <inline-formula><tex-math notation="LaTeX">10^{-3}</tex-math></inline-formula>, compared to existing approaches in 4-ary quadrature amplitude modulation (4-QAM) symbol modulation. When the number of antennas is increased to 24 and using 16-QAM, the proposed DeepEigen-Tabu provides an improvement of 0.5 dB in SNR performance. Specifically, the proposed DeepEigen-Tabu not only achieves superior performance, as mentioned earlier, but also incurs a lower computational cost. The performance enhancements can be attributed to the DeepEigNet's provision of effective initialization, along with the early stopping and efficient candidate movement mechanisms employed by the P-TS method.
MIMO orthogonal time frequency space (OTFS) modulation is considered a promising communication technology for future ultra-high-speed vehicular scenarios. However, the high complexity channel ...estimator and low accuracy symbol detection algorithm hinder the development of OTFS modulation. Unlike the conventional receiver, channel estimation and symbol detection are relatively isolated, we design a novel joint receiver combining channel estimation and symbol detection exploiting a partial iterative feedback mechanism. Firstly, we take into account the effect of fractional Doppler and make it approximate gridding. Therefore, the channel estimation problem is transformed into a block sparse signal recovery problem, and an efficient sparse adaptive block orthogonal matching pursuit (ABOMP) algorithm is proposed. Secondly, we propose a low-complexity approximate message passing (AMP) algorithm, which provides a reference for selecting high-confidence data symbols and reduces the redundant calculation of multiple detections. Finally, a partial iteration feedback joint detection and channel estimation (JDCE) algorithm is proposed to further reduce the system bit error ratio (BER) and computational complexity. Comprehensive simulation experiments are conducted and demonstrate the effectiveness and superiority of the proposed algorithm.
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