3,532 research outputs found
H-ARQ-Aided Systematic Luby Transform Codes
Hybrid Automatic-Repeat-Request (H-ARQ) Aided Systematic Luby Transform (SLT) Coded Modulation is proposed, where SLT codes are used both for correcting erroneous bits and for detecting as well as retransmitting erroneous Internet Protocol (IP) based packets. Erroneous IP packet detection is implemented using syndrome checking with the aid of the SLT codes’ Parity Check Matrix (PCM). Optimizing the mapping of SLT-encoded bits to modulated symbols and then using iterative decoding for exchanging extrinsic information between the SLT decoder and the demapper substantially improves the achievable Bit Error Ratio (BER) performance of the scheme. Quantitatively, at Eb/N0 in excess of 3.8 dB, this scheme is capable of achieving a BER 10?5 and up to 1.5 times higher throughput in comparison to less sophisticated benchmarker schemes such as SLT codes, dispensing with ARQ-assistance or joint SLT coded modulation and H-ARQ-SLT codes, when communicating over AWGN channels, using 16-QAM and a half-rate SLT code
Knowledge structure, knowledge granulation and knowledge distance in a knowledge base
AbstractOne of the strengths of rough set theory is the fact that an unknown target concept can be approximately characterized by existing knowledge structures in a knowledge base. Knowledge structures in knowledge bases have two categories: complete and incomplete. In this paper, through uniformly expressing these two kinds of knowledge structures, we first address four operators on a knowledge base, which are adequate for generating new knowledge structures through using known knowledge structures. Then, an axiom definition of knowledge granulation in knowledge bases is presented, under which some existing knowledge granulations become its special forms. Finally, we introduce the concept of a knowledge distance for calculating the difference between two knowledge structures in the same knowledge base. Noting that the knowledge distance satisfies the three properties of a distance space on all knowledge structures induced by a given universe. These results will be very helpful for knowledge discovery from knowledge bases and significant for establishing a framework of granular computing in knowledge bases
A study of anticipatory coarticulation for French speakers and for Mandarin Chinese speakers
International audienceAnticipatory coarticulation is studied for two languages, French and Mandarin Chinese, within Vowel1 -Consonant -Vowel2 sequences (V1CV2 henceforth). EMMA data and acoustic signals were collected. The influences of V2 on V1 and of V2 on C are more specifically analyzed in this paper. The results showed that, for the French speakers, vowel V2 influenced the whole sequence V1CV2, while its influence was limited to the syllable CV2 for the Chinese speakers. This suggested that speech planning in French is managed beyond the size of a syllable, while the planning is limited within the syllabe for Chinese. The results demonstrated the impact of language based constraints on articulatory planning in speech
The influence of online Danmu on users\u27 reward behavior: Based on the data of Douyu live broadcast
In live streaming, the Danmu is a crucial technique of interaction, and the reward is the interaction\u27s feedback. The audience receives more input through the reward the more frequently they interact. The effect of the bullet screen in the live broadcast on the audience\u27s reward behavior was investigated by gathering data from the live broadcast room 5720533 on Douyu, a domestic Danmu live-streaming website, from February 14 to February 24, 2021. Based on empirical research, the following conclusions can be drawn: the number of user Danmu, the proportion of fan Danmu, the number of user entry Danmu, and the number of super Danmu will all significantly improve users\u27 reward, while personal experience attenuates the positive impact of the number of user access Danmu and the number of super Danmu on the impact of user reward. The study\u27s findings will offer theoretical justification for the creation of live broadcast platforms, the upkeep of anchors\u27 notoriety, and users\u27 rational consumption
OFDM Systems for Optical Communication with Intensity Modulation and Direct Detection
Intensity modulation and direct detection (IM/DD) is a cost-effective optical communication strategy which finds wide applications in fiber communication, free-space optical communication, and indoor visible light communication. In IM/DD, orthogonal frequency division multiplexing (OFDM), originally employed in radio frequency communication, is considered as a strong candidate solution to combat with channel distortions. In this research, we investigate various potential OFDM forms that are suitable for IM/DD channel. We will elaborate the design principles of different OFDM transmitters and investigate different types of receivers including the proposed iterative receiver. In addition, we will analyze the spectral efficiency and decoding complexities of different OFDM systems to give a whole picture of their performance. Finally, simulation results are given to assess the detection performance of different receivers
The Validation of the Multicultural Supervision Scale
The Multicultural Supervision Scale (MSS) is a self-reported instrument aimed at measuring supervisors’ multicultural supervision competencies. A total of 308 individuals completed the present study for the purpose of validating the MSS with the consideration of the influence of social desirability. Results from a confirmatory factor analysis confirmed the three-factor structure of the MSS including Supervisory Skills, Supervisors’ Attitudes and Beliefs, and Stereotypes Toward Diverse Populations. Statistical evidence suggested that the MSS, which consists of 21 self-reported items, demonstrated a moderate level of internal consistency and validity of its construct. Directions for future research and implications to clinical supervision and counselor preparation are discussed
Molecular Cloning, Characterization and Expression Analysis of Calreticulin Gene in the Ant Polyrhachis vicina Roger (Hymenoptera: Formicidae)
Calreticulin (CRT) as a ubiquitous and highly conserved calcium-binding protein exists in endoplasmic reticulum (ER), which possesses a variety of biological functions in the regulation of cell calcium homeostasis, molecular chaperoning and innate immunity. In our research, the calreticulin homologous gene (refered as PvCRT) was cloned from the ant Polyrhachis vicina Roger (Hymenoptera: Formicidae), the full-length cDNA of PvCRT is 1584bp base pairs(bp), contains a 5’-untranslated region of 87bp and a 3’-untranslated region of 246bp. The open reading frame (ORF) of 1251bp encodes 416 amino acids. Using real-time quantitative RT-PCR to study PvCRT mRNA expression levels indicate that this gene was expressed in different developmental stages of castes of P. vicina. The mRNA expression level in both embryos and adults show that PvCRT gene may play some essential roles in the ant’s development
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