18 research outputs found
A study of Duan Yucai's (1735-1815) application of his phonological theories in Shuowen Jiezi Zhu
No full textpublished_or_final_versionChineseDoctoralDoctor of Philosoph
Grammatical diversity across the yue dialects
No full textThere is a general belief that Yue constitutes a highly uniform dialect group, with its members sharing a good number of structures and lexica with the regional prestige dialect, Cantonese. Based on our first hand data collected from the field, this paper∗ describes the lesser known grammatical diversity across the Yue dialects, which can be illustrated by the different uses of the following features: (a) ideophonic suffixes; (b) diminutive suffixes and tone sandhi; (c) perfective aspect markers and their position in the VP, and (d) neutral question forms. The survey includes nine dialects from different subgroups, most of which are spoken far away from the Pearl River Delta where Cantonese dominates. Our study reveals that while Cantonese has obvious influence over other members of Yue, the grammatical diversity neutral question forms. The survey includes nine dialects from different subgroups, most of which are spoken far away from the Pearl River Delta where Cantonese dominates. Our study reveals that while Cantonese has obvious influence over other members of Yue, the grammatical diversity across Yue cannot simply be overlooked.</p
Poly-functionality of the preverbal “acquire” in the Nanning Yue dialect of Chinese: an areal perspective
No full textAbstractThis paper aims to explore the origin and to reconstruct the path of the development of a preverbal element, glossed as ACQ here, in the Nanning Yue dialect (NY) spoken in the Guangxi Zhuang Autonomous Region in south-western China. Apart from being a full verb meaning “acquire”, this morpheme can also appear in preverbal and post-verbal positions, expressing different modalities. It is argued that the preverbal ACQ in Early Cantonese (i.e. the ancestral language of modern Cantonese spoken in the Pearl River Delta as well as NY) is relatively non-productive, and this leads us to consider that the emergence of this peculiar grammatical element in modern NY might involve external factors. One possible such factor is language contact. Specifically, we argue that the new readings derived from the preverbal ACQ in NY were transferred from Zhuang, the most common non-Sinitic language of the Tai-Kadai family in Guangxi, by contact-induced interference.</jats:p
BER and outage probability for cooperative relay networks
No full textIn every cooperative relay system, there is a protocol to define the cooperating strategy of the system. The protocols studied in this report consist of amplify-and-forward (AF), fixed decode-and-forward (FDF), selective decode-and-forward (SDF), and hybrid decode-amplify-forward (HDAF). A simple three-nodes model of cooperative relay system is used to simulate each protocol’s performance, with regards to its bit error rate (BER) and outage probability. This report analyses and highlights on the gain in performance achieved when employing cooperative communication over a direct point-to-point wireless transmission system. Apart from FDF, all other protocols have shown to achieve a significant gain of over 10 dB and 9 dB at a BER and an outage probability of 10-4, respectively. FDF instead shows no achievable gain in BER and has a poorer result in outage probability. With the increment of phase-shift keying (PSK) modulation size, AF shows the best BER performance when modulating with the BPSK scheme, while HDAF excels in both QPSK and 8PSK schemes. Using the outage probability metric, SDF and HDAF give the best comparable performance.Bachelor of Engineerin
A hybrid queueing model for fast broadband networking simulation
No full textPhDThis research focuses on the investigation of a fast simulation method for broadband
telecommunication networks, such as ATM networks and IP networks. As a result of
this research, a hybrid simulation model is proposed, which combines the analytical
modelling and event-driven simulation modelling to speeding up the overall
simulation.
The division between foreground and background traffic and the way of dealing with
these different types of traffic to achieve improvement in simulation time is the major
contribution reported in this thesis. Background traffic is present to ensure that proper
buffering behaviour is included during the course of the simulation experiments, but
only the foreground traffic of interest is simulated, unlike traditional simulation
techniques. Foreground and background traffic are dealt with in a different way.
To avoid the need for extra events on the event list, and the processing overhead,
associated with the background traffic, the novel technique investigated in this
research is to remove the background traffic completely, adjusting the service time of
the queues for the background traffic to compensate (in most cases, the service time
for the foreground traffic will increase). By removing the background traffic from the
event-driven simulator the number of cell processing events dealt with is reduced
drastically.
Validation of this approach shows that, overall, the method works well, but the
simulation using this method does have some differences compared with experimental
results on a testbed. The reason for this is mainly because of the assumptions behind
the analytical model that make the modelling tractable.
Hence, the analytical model needs to be adjusted. This is done by having a neural
network trained to learn the relationship between the input traffic parameters and the
output difference between the proposed model and the testbed. Following this
training, simulations can be run using the output of the neural network to adjust the
analytical model for those particular traffic conditions.
The approach is applied to cell scale and burst scale queueing to simulate an ATM
switch, and it is also used to simulate an IP router. In all the applications, the method
ensures a fast simulation as well as an accurate result
New pulse shapes for enhanced spectral efficiency in digital radio communications
No full textLinear modulation schemes such as phase shift keying (PSK) and quadrature amplitude modulation (QAM) are inherently spectrally efficient. This research seeks enhanced spectral efficiency by designing new spectrally efficient pulse shapes for such digital modulations. The pulses designed are of finite duration and exhibit zero intersymbol interference when received through an additive white Gaussian noise (AWGN) channel. It is shown that the resulting communications signals have optimal spectral roll-off while maintaining optimum bit error ratio performance when received via an AWGN channel. The bandwidths and power spectral densities of communications signals using these pulses are compared with traditional spectrally efficient communications signals.Approved for public release; distribution is unlimited.Singapore Defence Science and Technology Agency author (civilian).http://archive.org/details/newpulseshapesfo10945323
Receptor super-regenerativo de baixo consumo para redes corporais
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Elétrica, Florianópolis, 2014.O foco deste trabalho é a análise e o projeto de um receptor super-regenerativo voltado para aplicações biomédicas. Primeiramente, apresenta-se a fundamentação teórica da recepção super-regenerativa e, em seguida, mostra-se um circuito projetado segundo essa arquitetura, a qual incorpora um amplificador de baixo ruído, um oscilador e um detector de envoltória, além de um conversor balanceado-desbalanceado entre estes dois últimos. O projeto demonstra a vantagem dessa técnica para projetar receptores de baixa potência e elevada sensibilidade. Como o oscilador tende a ser o circuito com maior consumo elétrico em um receptor super-regenerativo, esta dissertação também apresenta uma técnica de projeto de osciladores para aplicações de baixa potência. O circuito é baseado no clássico oscilador Colpitts de porta comum com uma segunda fonte de realimentação positiva, a qual é fornecida por uma degeneração indutiva de porta. Esta técnica diminui a transcondutância requerida para originar as oscilações, o que faz com que seja possível reduzir a corrente de polarização e, consequentemente, o consumo de potência. Um protótipo foi produzido em uma tecnologia CMOS padrão de 0,18 µm para servir de prova de conceito. Simulações pós-leiaute demonstraram uma frequência de oscilação de 2,5 GHz com um ruído de fase de -112.9 dBc/Hz a uma frequência deslocada de 1 MHz da portadora, consumindo 124 µW a partir de uma tensão de alimentação de 0,575 V.Abstract : The goal of this work is the analysis and the design of a super-regenerative receiver aimed for biomedical applications. Firstly the theoretical foundation of the super-regenerative reception is presented and afterwards it is shown a circuit designed according such an architecture, which incorporates a lownoise amplifier, an oscillator, and an envelope detector, besides a balancedto- unbalanced converter between the last two. This project demonstrates the advantage of that technique to design low-power and high-sensitivity receivers. Since the oscillator tends to be the circuit with the highest power consumption in a super-regenerative receiver, this dissertation also presents an oscillator design technique for low-power applications. The circuit is based on the common-gate Colpitts oscillator with additional positive feedback provided by an inductive gate degeneration. This technique decreases the required transconductance to start-up oscillations, which makes possible to reduce the bias current and hence the power consumption. A prototype was designed in a standard 0.18 mm CMOS technology as a proof of concept. Post-layout simulations present an oscillating frequency of 2.5 GHz with a phase noise of -112.9 dBc/Hz at a 1 MHz offset frequency and consuming 124 mW from a 0.575-V supply voltage
String searching engine for virus scanning
No full textAbstract — A memory efficient hardware string searching engine for anti-virus applications is presented. The proposed QSV method is based on quick sampling of the input stream against fixed-length pattern prefixes, and on-demand verification of variable-length pattern suffixes. Patterns handled by the QSV method are required to have at least 16 bytes, and possess distinct 16-byte prefixes. The latter requirement can be fulfilled by a preprocessing procedure. The search engine uses the pipelined Aho-Corasick (P-AC) architecture developed by the first author to process 4- to 15-byte short patterns and a small number of exception cases. Our design was evaluated using the ClamAV virus database having 82888 strings with a total size that exceeds 8 Mbyte. In terms of byte count, 99.3 % of the pattern set is handled by the QSV method and 0.7 % of the pattern set is handled by P-AC. A pattern with distinct 16-byte prefix only occupies up to 3 lookup table entries in QSV. The overall memory cost of our system is about 1.4Mbyte, i.e. 1.4 bit per character of the ClamAV pattern set. The proposed method is memory-based, hence, updates to the pattern set can be accommodated by modifying the contents of the lookup tables without reconfiguring the hardware circuits. Index Terms—string searching, anti-virus system, system security, embedded system
