1,240 research outputs found
On Max-SINR Receiver for Hexagonal Multicarrier Transmission Over Doubly Dispersive Channel
In this paper, a novel receiver for Hexagonal Multicarrier Transmission (HMT)
system based on the maximizing Signal-to-Interference-plus-Noise Ratio
(Max-SINR) criterion is proposed. Theoretical analysis shows that the prototype
pulse of the proposed Max-SINR receiver should adapt to the root mean square
(RMS) delay spread of the doubly dispersive (DD) channel with exponential power
delay profile and U-shape Doppler spectrum. Simulation results show that the
proposed Max-SINR receiver outperforms traditional projection scheme and
obtains an approximation to the theoretical upper bound SINR performance within
the full range of channel spread factor. Meanwhile, the SINR performance of the
proposed prototype pulse is robust to the estimation error between the
estimated value and the real value of time delay spread.Comment: 6 pages. The paper has been published in Proc. IEEE GLOBECOM 2012.
Copyright transferred to IEEE. arXiv admin note: text overlap with
arXiv:1212.579
Max-SINR Receiver for HMCT Systems over Non-Stationary Doubly Dispersive Channel
In this paper, a maximizing Signal-to-Interference plus-Noise Ratio
(Max-SINR) receiver for Hexagonal Multicarrier Transmission (HMCT) system over
non-stationary doubly dispersive (NSDD) channel is proposed. The closed-form
timing offset expression of the prototype pulse for the proposed Max-SINR HMCT
receiver over NSDD channel is derived. Simulation results show that the
proposed Max-SINR receiver outperforms traditional projection scheme and
obtains an approximation to the theoretical upper bound SINR performance within
all the local stationarity regions (LSRs). Meanwhile, the SINR performance of
the proposed Max-SINR HMCT receiver is robust to the estimation error between
the estimated value and the real value of root mean square (RMS) delay spread.Comment: This paper has been accepted by URSI GASS 2014 and will be presented
in the proceeding of URSI GASS 201
Natural transformation of Thermotoga sp. strain RQ7
Background
Thermotoga species are organisms of enormous interest from a biotechnological as well as evolutionary point of view. Genetic modifications of Thermotoga spp. are often desired in order to fully release their multifarious potentials. Effective transformation of recombinant DNA into these bacteria constitutes a critical step of such efforts. This study aims to establish natural competency in Thermotoga spp. and to provide a convenient method to transform these organisms.
Results
Foreign DNA was found to be relatively stable in the supernatant of a Thermotoga culture for up to 6 hours. Adding donor DNA to T. sp. strain RQ7 at its early exponential growth phase (OD600 0.18 ~ 0.20) resulted in direct acquisition of the DNA by the cells. Both T. neapolitana chromosomal DNA and Thermotoga-E. coli shuttle vectors effectively transformed T. sp. strain RQ7, rendering the cells resistance to kanamycin. The kan gene carried by the shuttle vector pDH10 was detected by PCR from the plasmid extract of the transformants, and the amplicons were verified by restriction digestions. A procedure for natural transformation of Thermotoga spp. was established and optimized. With the optimized method, T. sp. strain RQ7 sustained a transformation frequency in the order of 10−7 with both genomic and plasmid DNA
Analysis of Electrohysterographic Signal Propagation Direction during Uterine Contraction:the Application of Directed Information
Attention allocation, factor stock adjustment, and high-quality product development
The manufacturing industry is the foundation for building and
strengthening a country. Micro-manufacturing enterprises are the
basis for the development of manufacturing, and products are
the core and life of enterprises. Based on micro data from industrial
enterprises, this study conducts a statistical measurement on
the indicators of high-quality product development. Taking the
Baidu Index as the proxy variable for attention allocation, the
influence of attention allocation on high-quality development of
products is systematically examined both theoretically and empirically;
Additionally, it seeks to ascertain whether factor stock
adjustment has a mediating effect. The findings are as follows: 1.
Within the full sample, 63.63% of the attention allocation process
to promote high-quality development of products is achieved by
optimizing the factor stock adjustment channels. 2. Capital stock
and labor stock adjustment have a partial mediating effect on the
high-quality development of products in capital-intensive industries,
while labor stock adjustment has a partial mediating effect
on labor-intensive industries. 3. The regional results show that the
adjustment of capital and labor stock has a partial mediating
effect in the eastern region. This conclusion provides a theoretical
basis for realizing the high-quality development of China’s manufacturing
industry
Fault Tolerant Control Schemes for Wireless Networked Control Systems with an Integrated Scheduler
In recent years, the wireless networked control systems (W-NCSs) has gained increasing popularity in industrial processes. To guarantee the system control performance, fault tolerant control (FTC) strategies have been proposed especially to deal with the malfunction in sensors, actuators or other system components. For the real-time requirement in industrial systems, the FTC performances of W-NCSs not only depend on the developed control algorithms but also on the network protocols at the medium access control (MAC) layer. These protocols, in form of schedulers, determine the transmission orders of messages and play significant roles in the control performances of W-NCSs. Under these circumstances, it is challenging but promising to investigate FTC schemes for W-NCSs with an integrated scheduler.
This thesis is devoted to the development of FTC strategies for W-NCSs with an integrated scheduler. In the first part of this thesis, the procedures of integrating a scheduler into W-NCSs are introduced. Due to the requirement for deterministic transmission behaviors via the wireless network, the time division multiple access (TDMA) mechanism is adopted in W-NCSs. The TDMA-based scheduler is taken as a dynamic system and formulated into a periodic system. After that, with the integration of the scheduler, the W-NCSs are modeled as discrete linear time periodic (LTP) systems.
The second part of this thesis focuses on the developments of FTC schemes for the integrated LTP systems. Two types of faults, i.e., additive faults (AFs) and multiplicative faults (MFs), are considered in our work. Specifically, a group of fault tolerant controllers are constructed for the AFs case, and seek to ensure that the outputs of LTP systems satisfy a set of H_infty performance indices. On the other hand, a lifting technology and an adaptive observer are applied to handle the situation of MFs. Due to the distribution of W-NCSs and the limitation of communication bandwidth, theorems are presented to solve the structure-restriction problem in the gains of observers and controllers.
Finally, the derived FTC approaches are verified on an advanced experimental WiNC (wireless networked control) platform. Following the structure-restricted gains, the FTC strategies are realized with shared and unshared information (i.e., residual signals and state estimates), respectively. The results indicate that the system with shared information has achieved better FTC performances.
In den letzten Jahren, haben die drahtlos vernetzten Steuerungssystemen (W-NCSs) sich zunehmender Beliebtheit in industriellen Prozessen gewonnen. Um die Systemsteuerleistung zu gewährleisten, sind die fehlertoleranten Regelung (FTC) Strategien vorgeschlagen worden, um vor allem mit der Fehlfunktion in Sensoren, Aktoren oder andere Systemkomponenten umzugehen. Für die Echtzeitanforderung in industriellen Systemen, hängen die FTC-Leistungen der W-NCSs nicht nur von den entwickelten Regleralgorithmen sondern auch von den Netzwerkprotokollen auf dem Medium Access Control (MAC)-Layer ab. Diese Protokolle, in Form von Schedulers, bestimmen die Reihenfolge der Übertragung der Nachrichten und spielen eine bedeutende Rolle in den Steuerleistungen von W-NCSs. Unter diesen Umständen ist es herausfordernd aber vielversprechend um FTC Regelungen für W-NCSs mit einem integrierten Scheduler zu untersuchen.
Diese Arbeit widmet sich auf die Entwicklung von FTC Strategien für W-NCSs mit einem integrierten Scheduler. Im ersten Teil der Arbeit werden die Verfahren der Integration einen Scheduler in W-NCSs eingeführt. Aufgrund der Anforderung deterministisches Übertragungsverhalten über das drahtlose Netzwerk zu gewährleisten, wird der Time-Division-Multiple-Access (TDMA) Mechanismus gewählt. Der TDMA-basierte Scheduler ist als ein dynamisches System betrachtet und als ein Periodisches system formuliert. Danach, mit der Integration des Schedulers, werden die W-NCSs als diskrete Linear Time Periodic (LTP)-Systeme modelliert.
Der zweite Teil der Arbeit konzentriert sich auf die Entwicklung der FTC Regelungen für die integrierten LTP-Systeme. Zwei Arten von Fehlern, d.h., additive Fehlern (AFs) und multiplikativen Fehlern (MFs), sind in unserer Arbeit berücksichtigt. Für LTP-Systeme mit AFs wird ein Satz von fehlertoleranten Reglern entworfen, dass die Ausganggröße eine Reihe von H_infty-Leistungsindizes erfüllen werden. Auf der anderen Seite, werden ein Hebetechnik und eine adaptive Beobachter angewendet, um den Fall von MFs zu behandeln. Aufgrund der Verbreitung der W-NCSs und gleichzeitiger Begrenzung der Kommunikationsbandbreite werden Theoreme vorgestellt, um das Problem der Strukturbeschränkung in den Beobachter- bzw. Reglermatrizen zu lösen.
Abschließend werden die hergeleiteten FTC-Ansätze auf einem fortgeschrittenen WiNC (drahtlos vernetzten Regelung) Plattform überprüft. Nach den Beobachter- bzw. Reglermatrizen sind die FTC-strategien mit vollständig geteilter oder nicht geteilter Informationen (d.h., Residuum Signale und Schätzungen der Zustandsgrößen) realisiert worden. Die Ergebnisse zeigen, dass das System mit vollständig geteilten Informationen bessere FTC-Leistungen erzielt hat
Construction and Transformation of a Thermotoga-E. coli Shuttle Vector
Background: Thermotoga spp. are attractive candidates for producing biohydrogen, green chemicals, and thermostable enzymes. They may also serve as model systems for understanding life sustainability under hyperthermophilic conditions. A lack of genetic tools has hampered the investigation and application of these organisms. This study aims to develop a genetic transfer system for Thermotoga spp. Results: Methods for preparing and handling Thermotoga solid cultures under aerobic conditions were optimized. A plating efficiency of similar to 50% was achieved when the bacterial cells were embedded in 0.3% Gelrite. A Thermotoga-E. coli shuttle vector pDH10 was constructed using pRQ7, a cryptic mini-plasmid found in T. sp. RQ7. Plasmid pDH10 was introduced to T. maritima and T. sp. RQ7 by electroporation and liposome-mediated transformation. Transformants were isolated, and the transformed kanamycin resistance gene (kan) was detected from the plasmid DNA extracts of the recombinant strains by PCR and was confirmed by restriction digestions. The transformed DNA was stably maintained in both Thermotoga and E. coli even without the selective pressure. Conclusions: Thermotoga are transformable by multiple means. Recombinant Thermotoga strains have been isolated for the first time. A heterologous kan gene is functionally expressed and stably maintained in Thermotoga
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