A Novel Packet Marking Function for Real-Time Interactive MPEG-4 Video Applications in a Differentiated Services Network

The future convergence of voice, video and data applications on the Internet requires that next generation technology provides bandwidth and delay guarantees. Current technology trends are moving towards scalable aggregate-based systems where applications are grouped together and guarantees are provided at the aggregate level only. This solution alone is not enough for interactive video applications with sub-second delay bounds. This paper introduces a novel packet marking scheme that controls the end-to-end delay of an individual flow as it traverses a network enabled to supply aggregate- granularity Quality of Service (QoS). IPv6 Hop-by-Hop extension header fields are used to track the packet delay encountered at each network node and autonomous decisions are made on the best queuing strategy to employ. The results of network simulations are presented and it is shown that when the proposed mechanism is employed the requested delay bound is met with a 20% reduction in resource reservation and no packet loss in the network.

Human Dignity and judicial Interpretation of Human Rights

The Universal Declaration on Human Rights was pivotal in popularizing the use of 'dignity' or 'human dignity' in human rights discourse. This article argues that the use of 'dignity', beyond a basic minimum core, does not provide a universalistic, principled basis for judicial decision-making in the human rights context, in the sense that there is little common understanding of what dignity requires substantively within or across jurisdictions. The meaning of dignity is therefore context-specific, varying significantly from jurisdiction to jurisdiction and (often) over time within particular jurisdictions. Indeed, instead of providing a basis for principled decision-making, dignity seems open to significant judicial manipulation. increasing rather than decreasing judicial discretion. That is one of its significant attractions to both judges and litigators alike. Dignity provides a convenient language for the adoption of substantive interpretations of human rights guarantees which appear to be intentionally, not just coincidentally. highly contingent on local circumstances. Despite that, however, I argue that the concept of 'human dignity' plays an important role in the development of human rights adjudication, not in providing an agreed content to human rights but in contributing to particular methods of human rights interpretation and adjudication.

The Diffusion of Risks in Public Private Partnership Contracts

Purpose The UK government argues that the benefits of public private partnership (PPP) in delivering public infrastructure stem from: transferring risks to the private sector within a structure in which financiers put their own capital at risk; and, the performance based payment mechanism, reinforced by the due diligence requirements imposed by the lenders financing the projects (HM Treasury, 2010). Prior studies of risk in PPPs have investigated ‘what’ risks are allocated and to ‘whom’, that is to the public or the private sector. The purpose of this study is to examine ‘how’ and ‘why’ PPP risks are diffused by their financiers. Design/methodology/approach This study focuses on the financial structure of PPPs and on their financiers. Empirical evidence comes from interviews conducted with equity and debt financiers. Findings The findings show that the financial structure of the deals generates risk aversion in both debt and equity financiers and that the need to attract affordable finance leads to risk diffusion through a network of companies using various means that include contractual mitigation through insurance, performance support guarantees, interest rate swaps and inflation hedges. Because of the complexity this process generates, both procurers and suppliers need expensive expert advice. The risk aversion and diffusion and the consequent need for advice add cost to the projects impacting on the government’s economic argument for risk transfer. Limitations and implications The empirical work covers the private finance initiative (PFI) type of PPP arrangements and therefore the risk diffusion mechanisms may not be generalisable to other forms of PPP, especially those that do not involve the use of high leverage or private finance. Moreover, the scope of this research is limited to exploring the diffusion of risk in the private sector. Further research is needed on how risk is diffused in other settings and on the value for money implication of risk diffusion in PPP contracts. Originality/value The expectation inherent in PPP is that the private sector will better manage those risks allocated to it and because private capital is at risk, financiers will perform due diligence with the ultimate outcome that only viable projects will proceed. This paper presents empirical evidence that raises questions about these expectations. Key words: public private partnership, risk management, diffusion, private finance initiative, financiers

Evaluating the impact of network density, hidden nodes and capture effect for throughput guarantee in multi-hop wireless networks

To optimize the performance of wireless networks, one needs to consider the impact of key factors such as interference from hidden nodes, the capture effect, the network density and network conditions (saturated versus non-saturated). In this research, our goal is to quantify the impact of these factors and to propose effective mechanisms and algorithms for throughput guarantees in multi-hop wireless networks. For this purpose, we have developed a model that takes into account all these key factors, based on which an admission control algorithm and an end-to-end available bandwidth estimation algorithm are proposed. Given the necessary network information and traffic demands as inputs, these algorithms are able to provide predictive control via an iterative approach. Evaluations using analytical comparison with simulations as well as existing research show that the proposed model and algorithms are accurate and effective.

Design of latch-based C-element

The C-element logic gate is a key component for constructing asynchronous control in silicon integrated circuits. The purpose of this reported work is to introduce a new speed-independent C-element design, which is synthesised by the asynchronous Petrify design tool to ensure it is composed of sequential digital latches rather than complex gates. The benefits are that it guarantees correct speed-independent operation, together with easy integration in modern design flows and processes. It is compared to an equivalent speed-independent complex gate C-element design generated by Petrify in a 130 nm semiconductor process.

Design and analysis of dual-rail circuits for security applications

Dual-rail encoding, return-to-spacer protocol, and hazard-free logic can be used to resist power analysis attacks by making energy consumed per clock cycle independent of processed data. Standard dual-rail logic uses a protocol with a single spacer, e.g., all-zeros, which gives rise to energy balancing problems. We address these problems by incorporating two spacers; the spacers alternate between adjacent clock cycles. This guarantees that all gates switch in every clock cycle regardless of the transmitted data values. To generate these dual-rail circuits, an automated tool has been developed. It is capable of converting synchronous netlists into dual-rail circuits and it is interfaced to industry CAD tools. Dual-rail and single-rail benchmarks based upon the advanced encryption standard (AES) have been simulated and compared in order to evaluate the method and the tool.

DNA methyltransferase expression in the mouse germ line during periods of de novo methylation

DNA methyltransferase (DNMT) 3A and DNMT3B are both active de novo DNA methyltransferases required for development, whereas DNMT3L, which has no demonstrable methyltransferase activity, is required for methylation of imprinted genes in the oocyte. We show here that different mechanisms are used to restrict access by these proteins to their targets during germ cell development. Transcriptional control of the Dnmt3l promoter guarantees that message is low or absent except during periods of de novo activity. Use of an alternative promoter at the Dnmt3a locus produces the shorter Dnmt3a2 transcript in the germ line and postimplantation embryo only, whereas alternative splicing of the Dnmt3b transcript ensures that Dnmt3b1 is absent in the male prospermatogonia. Control of subcellular protein localization is a common theme for DNMT3A and DNMT3B, as proteins were seen in the nucleus only when methylation was occurring. These mechanisms converge to ensure that the only time that functional products from each locus are present in the germ cell nuclei is around embryonic day 17.5 in males and after birth in the growing oocytes in females.

Xheal: A localized self-healing algorithm using expanders

We consider the problem of self-healing in reconfigurable networks e.g., peer-to-peer and wireless mesh networks. For such networks under repeated attack by an omniscient adversary, we propose a fully distributed algorithm, Xheal, that maintains good expansion and spectral properties of the network, while keeping the network connected. Moreover, Xheal does this while allowing only low stretch and degree increase per node. The algorithm heals global properties like expansion and stretch while only doing local changes and using only local information. We also provide bounds on the second smallest eigenvalue of the Laplacian which captures key properties such as mixing time, conductance, congestion in routing etc. Xheal has low amortized latency and bandwidth requirements. Our work improves over the self-healing algorithms Forgiving tree [PODC 2008] andForgiving graph [PODC 2009] in that we are able to give guarantees on degree and stretch, while at the same time preserving the expansion and spectral properties of the network.

VEDA:Variation-aware energy-efficient discrete Wavelet Transform architecture

In this paper, we present a unified approach to an energy-efficient variation-tolerant design of Discrete Wavelet Transform (DWT) in the context of image processing applications. It is to be noted that it is not necessary to produce exactly correct numerical outputs in most image processing applications. We exploit this important feature and propose a design methodology for DWT which shows energy quality tradeoffs at each level of design hierarchy starting from the algorithm level down to the architecture and circuit levels by taking advantage of the limited perceptual ability of the Human Visual System. A unique feature of this design methodology is that it guarantees robustness under process variability and facilitates aggressive voltage over-scaling. Simulation results show significant energy savings (74% - 83%) with minor degradations in output image quality and avert catastrophic failures under process variations compared to a conventional design. © 2010 IEEE.

DEX: Self-Healing Expanders

We present a fully-distributed self-healing algorithm DEX, that maintains a constant degree expander network in a dynamic setting. To the best of our knowledge, our algorithm provides the first efficient distributed construction of expanders - whose expansion properties hold deterministically - that works even under an all-powerful adaptive adversary that controls the dynamic changes to the network (the adversary has unlimited computational power and knowledge of the entire network state, can decide which nodes join and leave and at what time, and knows the past random choices made by the algorithm). Previous distributed expander constructions typically provide only probabilistic guarantees on the network expansion which rapidly degrade in a dynamic setting, in particular, the expansion properties can degrade even more rapidly under adversarial insertions and deletions. Our algorithm provides efficient maintenance and incurs a low overhead per insertion/deletion by an adaptive adversary: only O(log n) rounds and O(log n) messages are needed with high probability (n is the number of nodes currently in the network). The algorithm requires only a constant number of topology changes. Moreover, our algorithm allows for an efficient implementation and maintenance of a distributed hash table (DHT) on top of DEX, with only a constant additional overhead. Our results are a step towards implementing efficient self-healing networks that have guaranteed properties (constant bounded degree and expansion) despite dynamic changes.

Efficient Structure Learning of Bayesian Networks using Constraints

This paper addresses the problem of learning Bayesian network structures from data based on score functions that are decomposable. It describes properties that strongly reduce the time and memory costs of many known methods without losing global optimality guarantees. These properties are derived for different score criteria such as Minimum Description Length (or Bayesian Information Criterion), Akaike Information Criterion and Bayesian Dirichlet Criterion. Then a branch-and-bound algorithm is presented that integrates structural constraints with data in a way to guarantee global optimality. As an example, structural constraints are used to map the problem of structure learning in Dynamic Bayesian networks into a corresponding augmented Bayesian network. Finally, we show empirically the benefits of using the properties with state-of-the-art methods and with the new algorithm, which is able to handle larger data sets than before.

Gaining ethical approvals to undertake sexual health research with young people in the UK: Applying a 'Children's Rights Based Approach'

This paper (co-written with Dr Maria Lohan, Dr Carmel Kelly & Professor Laura Lundy) will describe the ethical review process to undertake health research in the UK, and explain an approach that can help researchers deal with ethical and methodological dilemmas in their research. Ethical review is necessary to ensure researchers and participants are protected, yet the requirement to ‘pass’ numerous committees may be challenging particularly for health researchers who work with vulnerable groups and sensitive topics. The inclusion of these groups/topics is crucial if health researchers are to understand health disparities and implement appropriate interventions with health benefits for vulnerable populations. It is proposed that to overcome ethical and methodological challenges and pitfalls, researchers must implement strategies that advocate for, and increase the participation of, vulnerable populations in health research. A ‘children’s rights based approach’ using participatory methodology will be described that draws on the jurisprudence of international law, (United Nations Convention on the Rights of the Child, 1989) and provides a framework that may empower ethics committees to carry out their function confidently. The role of the researcher, framed within the context of doctoral level study, will be reviewed in terms of the investment required and benefits of utilising this approach. It will be argued that adopting this approach with vulnerable groups, not only guarantees their meaningful participation in the research process and permits their voices to be heard, but also offers ethics committees an internationally agreed upon legal framework, ratified by their governing States, from which to fulfil their obligations and resolve their ethical dilemmas. Increasing the representation and participation of vulnerable groups in health research can inform the development of health policy and practice based on ‘insider knowledge’ that better engages with and more adequately reflects their specific needs. This is likely to yield numerous health, social and economic benefits for all of society through the delivery of more equitable, effective and sustainable services.

Considerations in the sterile manufacture of polymeric microneedle arrays

We describe, for the first time, considerations in the sterile manufacture of polymeric microneedle arrays. Microneedles (MN) made from dissolving polymeric matrices and loaded with the model drugs ovalbumin (OVA) and ibuprofen sodium and hydrogel-forming MN composed of "super-swelling" polymers and their corresponding lyophilised wafer drug reservoirs loaded with OVA and ibuprofen sodium were prepared aseptically or sterilised using commonly employed sterilisation techniques. Moist and dry heat sterilisation, understandably, damaged all devices, leaving aseptic production and gamma sterilisation as the only viable options. No measureable bioburden was detected in any of the prepared devices, and endotoxin levels were always below the US Food & Drug Administration limits (20 endotoxin units/device). Hydrogel-forming MN were unaffected by gamma irradiation (25 kGy) in terms of their physical properties or capabilities in delivering OVA and ibuprofen sodium across excised neonatal porcine skin in vitro. However, OVA content in dissolving MN (down from approximately 101.1 % recovery to approximately 58.3 % recovery) and lyophilised wafer-type drug reservoirs (down from approximately 99.7 % recovery to approximately 60.1 % recovery) was significantly reduced by gamma irradiation, while the skin permeation profile of ibuprofen sodium from gamma-irradiated dissolving MN was markedly different from their non-irradiated counterparts. It is clear that MN poses a very low risk to human health when used appropriately, as evidenced here by low endotoxin levels and absence of microbial contamination. However, if guarantees of absolute sterility of MN products are ultimately required by regulatory authorities, it will be necessary to investigate the effect of lower gamma doses on dissolving MN loaded with active pharmaceutical ingredients and lyophilised wafers loaded with biomolecules in order to avoid the expense and inconvenience of aseptic processing.