2,509 research outputs found
Distributed video coding for wireless video sensor networks: a review of the state-of-the-art architectures
Distributed video coding (DVC) is a relatively new video coding architecture originated from two fundamental theorems namely, Slepian–Wolf and Wyner–Ziv. Recent research developments have made DVC attractive for applications in the emerging domain of wireless video sensor networks (WVSNs). This paper reviews the state-of-the-art DVC architectures with a focus on understanding their opportunities and gaps in addressing the operational requirements and application needs of WVSNs
Design and simulation of reversible molecular mechanical logic gates and circuits
In this thesis, I outline a framework for constructing molecular mechanical circuits from logic gates and components that I have designed and optimised, and describe the results of simulations conducted to determine the thermodynamic properties of these circuits with a coarse-grained rigid body simulator. The molecular mechanical logic gates I have designed can be used to construct logically reversible circuits, which have the potential to be far more efficient than their irreversible counterparts due to the fact that they can easily be operated in a thermodynamically reversible manner.
Using the rigid body simulator, I first demonstrate Landauer's principle, a fundamental principle of information theory which relates the change in information entropy of a given process to the work required to complete it, thus showing that my rigid body simulator is thermodynamically self-consistent. I then simulate a novel molecular mechanical NAND gate design and use it to construct complex logically and thermodynamically reversible combinatorial circuits, including a half-adder. Subsequently, I investigate the use of pipelining to increase the throughput of a circuit at the cost of potential logical irreversibility, and show that it is possible to perform pipelining efficiently under certain conditions. Finally, I use a genetic algorithm to optimise various circuit components, demonstrating a novel technique to reduce the number of costly simulations that must be run in order to calculate the fitness function
Strategies To Enhance Teaching And Learning In A Rapidly Changing Economy
The Singapore economy is undergoing rapid structural changes with new industries emerging while old industries slow down. This means that workers have to constantly acquire new knowledge and skills to take on the new challenges in the economy. Teaching and learning in a changing economy takes on a new perspective in the light of a rising number of adult learners who work by day and become students in the evening. This paper examines the different strategies that lecturers could implement to enhance their teaching and facilitate students in their learning experiences
Behaviour of Corrugated Composite Tube Under Compressive Load Using Finite Element Method
This work focuses on studying the effect of composite corrugated tubes’ crushing behaviour and to identify the optimised energy-absorption orientation of composite material lamination subjected to the axially compressive load. Parametric study was conducted to investigate the effect of the corrugated angles and fibre orientations on the energy absorb using the E-Glass fibre/epoxy Corrugated Cylindrical Composite Tubes (CCCT) in woven roving form. Twenty different orientations ([0/0/0], [30/0/0], [0/45/0], [60/0/0], [30/0/30], [30/45/0], [60/0/30], [45/0/45], [60/45/0], [60/0/60], [30/30/30], [30/45/30], [60/30/30], [30/45/45], [60/45/30], [30/60/60], [45/45/45], [60/45/45], [60/45/60], [60/60/60]) of E-Glass fibre/epoxy in woven roving laminations were fabricated for this purpose. Nevertheless, only three randomly chosen corrugated angles (5 degrees, 20 degrees & 35 degrees) were used for finite element analysis. Typical failure histories of their failure mechanisms are presented and discussed. Results showed that the crushing behaviour and the energy-absorption level of composite corrugated tube are found to be different when changes are made to the orientation of lamination of the composite material. CCCTs with the lowest corrugation angles resulted with highest initial crushing load and the highest average crushing load, and vice-versa. Meanwhile, CCCTs with the low corrugated angle requires thorough study before being used as an energy absorption device because their initial crush load that is too much greater than the average crush load itself. However, the best energy absorbing CCCT for this work should have the highest possible energy absorbed per unit mass (Es) while compensating for least possible differences between initial crush load and average crush load. With this criterion, CCCT with a corrugated angle of 20 degrees and [60/0/60] lamination orientation fulfilled the requirement. At the same time, the result of this work also shows that the average Es for CCCT with a lower corrugated angle is higher than the CCCT with a higher corrugated angle. Subsequently, the usage of 5, 20 and 35 degrees corrugated angles has generally covered the range of corrugated angles from 0 degree to 45 degrees because as the corrugated angle of CCCTs increases, the average Es of CCCT will reduce and will no longer significant in this project. CCCT with a corrugated angle of beyond 45 degrees will cause the woven roving composite material of CCCT to perform beyond the intended strength of direction. In addition, corrugated angles between 45 degrees and 90 degrees are similar to corrugated angles from 0 degree to 45 degrees. Thus, no study on CCCTs with corrugated angle beyond 45 degrees is required
Rediscover Rosarito: a public diplomacy initiative for the local community in Rosarito Beach, Baja Mexico
Rediscover Rosarito is a cross-cultural public affairs graduate class initiative started in February 2008. That
year, 28 graduate Communication Management (CM) students from diverse backgrounds and nationalities,
taught by Dr. Gregory Payne of the Communication Studies Department, reached out to elected
governmental leaders, public officials, citizens and expatriates of Rosarito Beach in Baja Mexico. Together,
they launched a public affairs campaign that stressed the importance of grassroots public diplomacy as a
major strategy.
The goal of the program then and now is to develop and implement an ongoing campaign to help restore
the image of this heavily tourism dependent beach community, which had been devastated by a drastic drop
in visitor levels as a result of Mexican President Jose Caledron’s ‘war on drugs,’ a violent reaction from the
drug cartels against this action, as well as biased media coverage regarding the crisis from sources on both
sides of the border, which reflect the all too often proclivity of the media to sensationalize such stores in the
effort to secure readershi
Surviving the Survival Narrative Part 1: Internalised Racism and the Limits of Resistance
The concept of internalised racism (IR) has been criticised for its potential utilisation to perpetuate ‘victim blaming’. In describing the racialised subject’s indoctrination to racist beliefs about themselves and/or their group, the concept of IR has been a point of difficulty for scholarship which sustains a hyper-focus on racialised resistance towards structural racism and its effects. Some scholars have highlighted that this hyper-focus on resistance is connected to a political stance which essentialises racialised subjects as always resisting. In this article, I further this argument by demonstrating the limitations within resistance strategies employed by some racialised subjects. I utilise participants’ narratives from a wider study to highlight three forms of limitations (conscious renouncing, inadvertent complicity, and non-resistance) in resisting racist ideology. I then draw on these examples to problematise scholarship that sustain a hyper-focus on resistance, one that may inadvertently foreclose the deeper impact of racism upon the racialised
Mobile P2Ping: A Super-Peer based Structured P2P System Using a Fleet of City Buses
Recently, researchers have introduced the notion of super-peers to improve signaling efficiency as well as lookup performance of peer-to-peer (P2P) systems. In a separate development, recent works on applications of mobile ad hoc networks (MANET) have seen several proposals on utilizing mobile fleets such as city buses to deploy a mobile backbone infrastructure for communication and Internet access in a metropolitan environment. This paper further explores the possibility of deploying P2P applications such as content sharing and distributed computing, over this mobile backbone infrastructure. Specifically, we study how city buses may be deployed as a mobile system of super-peers. We discuss the main motivations behind our proposal, and outline in detail the design of a super-peer based structured P2P system using a fleet of city buses.Singapore-MIT Alliance (SMA
Estimating the Postmortem Interval in Freshwater Environments
Forensic investigators often deal with human remains recovered from water. Estimating the time since death for bodies that have been submerged in water can be quite difficult because there is a lack of data on the subject. This preliminary study was intended to provide additional data through the use of record research. Autopsy reports containing cases in which human remains were recovered from bodies of freshwater were used. Thirty-one variables were collected from each report in a present/absent context. Nine of the variables were then used in logistic regression analyses in order to measure their relationship to time in water. Results from this research indicate that only three of the variables were significant and the time since death estimate can only be made in large time intervals. The three variables: purge, hair slippage, and marbling can narrow the postmortem interval to either 48 hours or less or greater than 48 hours
Genome sequence of bacteriophage ΦAR29: a basis for integrative plasmid vectors
The initial aim of this project was to characterise the integrative recombination mechanism of bacteriophage ΦAR29 , to provide a better understanding for development of the shuttle plasmid pBA as a site-specific Bacteroides integration vector. RT-PCR showed that the previously identified ΦAR29 recombination genes, integrase (Int) and excisionase (Xis), were transcribed from pBA in E. coli SCS110, B. thetaiotaomicron AR29 and B. uniformis AR20. In silico derived amino acid sequences from both genes showed only very low levels of similarity to other known Int and Xis in GenBank. To improve understanding of the phage recombination system, the ΦAR29 genome was sequenced. This revealed a 35,558 bp double-stranded DNA genome with GC content of 39.11%. Bioinformatic analysis identified 53 open reading frames (>30 codons) and gene promoters and terminators that allowed the genome arrangement to be compared with other phages. Comparison of deduced gene products with proteins from other phages identified 6 reading frames, allowed tentative identification of 7 others, but left 40 ORFs unidentified. Those with strong homology to known genes were: large terminase subunit (44.66 kDa), dnaC (27.94 kDa), helix-turn-helix (HTH) transcription regulator (14.69 kDa), cI repressor (26.48 kDa), amidase (18.42kDa) and a novel integrase (54.22 kDa). The integrase gene is located 162 base-pairs downstream of the phage attachment (attP) core site, rather than the previously suggested location upstream of the integration site. The ΦAR29 attP was shown to include a 16-bp att core region, 117 bp upstream of the previously suggested location. Integration of ΦAR29 was found to occur at the 3'end of an arg-tRNA gene on the AR29 genome (attB). Imperfect direct repeats with a consensus sequence (ANGTTGTGCAA) were found surrounding the attP core. A review of pBA sequence showed that only the 5' end (435 bp) of the newly identified Int gene was cloned in pBA. Despite this, PCR analysis revealed integration of pBA into the AR29 genome. Serial subculturing of pBA transformed AR29 was able to cure AR29 of the ΦAR29 prophage, providing an improved host for integrative plasmids, and for detailed studies of AR29 physiology and ΦAR29 life cycles
- …