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Modelling corporate bank accounts
Get PDFYesWe discuss the modelling of corporate bank accounts using a proprietary dataset. We thus
offer a principled treatment of a genuine industrial problem. The corporate bank accounts
in our study constitute spare, irregularly-spaced time series that may take both positive and
negative values. We thus builds on previous models where the underlying is real-valued. We
describe an intra-monthly effect identified by practitioners whereby account uncertainty is
typically lowest at the beginning and end of each month and highest in the middle. However,
our theory also allows for the opposite effect to occur. In-sample applications demonstrate
the statistical significance of the hypothesised monthly effect. Out-of-sample forecasting
applications offer a 9% improvement compared to a standard SARIMA approach
Denial of service detection using dynamic time warping
Get PDFYesWith the rapid growth of security threats in computer networks, the need for developing efficient security‐warning systems is substantially increasing. Distributed denial‐of‐service (DDoS) and DoS attacks are still among the most effective and dreadful attacks that require robust detection. In this work, we propose a new method to detect TCP DoS/DDoS attacks. Since analyzing network traffic is a promising approach, our proposed method utilizes network traffic by decomposing the TCP traffic into control and data planes and exploiting the dynamic time warping (DTW) algorithm for aligning these two planes with respect to the minimum Euclidean distance. By demonstrating that the distance between the control and data planes is considerably small for benign traffic, we exploit this characteristic for detecting attacks as outliers. An adaptive thresholding scheme is implemented by adjusting the value of the threshold in accordance with the local statistics of the median absolute deviation (MAD) of the distances between the two planes. We demonstrate the efficacy of the proposed method for detecting DoS/DDoS attacks by analyzing traffic data obtained from publicly available datasets.The Deanship of Scientific Research, King Saud University. The Gulf Science, Innovation, and Knowledge Economy Programme of the U.K. Governmen
Global Security in the Post-Cold War Era and the Relevance of Nuclear Weapons
Get PDFYesAre nuclear weapons still relevant to global
security? Compared with the nuclear confrontation
in the depths of the Cold War, nuclear weapons and
deterrence appear to have lost their salience.
Considering the conflicts in which the major powers
engaged, the focus in strategic studies changed to
counterinsurgency, counterterrorism, and subconventional conflict.2 Only recently, with the
conflict in Ukraine and the increasingly
confrontational relationship between the United
States and China has this narrative come into
question. The general perception on international
security exhibits a strange paradox. On the one
hand the US-led military interventions in
Afghanistan, Iraq and other parts, the conflicts in
the Middle East and Africa, the nuclearization of
North Korea and the conflict between India and
Pakistan among other regional security issues have
given rise to a view that the modern world is less
secure than ever, and we live in a world of chaos
riven by unpredictable patterns of violence. By
contrast, Steven Pinker has demonstrated the casualties from armed conflict are at their lowest
point in human history, and interstate warfare has
virtually ceased to exist as a phenomenon.3 The
imminence of a global nuclear war in which at a
minimum hundreds of millions of people would die
appears to have dissipated. In some respects, it
appears that war has become almost a
phenomenon of the past. Most of the recent
literature on nuclear weapons has focused on
regional crises areas, such as South Asia (India and
Pakistan) or the Korean peninsula.4 However, the
modernization of arsenals by the nuclear powers,
the integration of strategic conventional and
nuclear weapons in strategic doctrines and the
more confrontational dynamics in Great Power
politics is cited as evidence that the risk of nuclear
use is increasing. This paper contests the emerging
narratives on an increased threat of nuclear conflict
and considers the sources of insecurity in the
contemporary period and in particular the risks of
armed conflict between the United States, Russia,
and China in order to assess the role of nuclear
weapons in contemporary security
Drawn from life: Cocreating narrative and graphic vignettes of lived experience with people affected by dementia
Get PDFYesThe growing literature on Patient and Public Involvement and Engagement (PPIE) and dementia identifies specific problems related to the influence involvement has on research outcomes, over-reliance on family members as proxies, and lack of representation of seldom-heard groups. Adaptations to the PPIE process are therefore needed in order to make possible the involvement of a broader spectrum of people living with dementia.
To adapt the PPIE process in order to make participation in co-creation by people living with dementia accessible and meaningful across a spectrum of cognitive abilities.
Design: Narrative elicitation, informal conversation, and observation were used to co-create three vignettes based on PPIE group members’ personal experience of dementia services. Each vignette was produced in both narrative and graphic formats.
Participants: Nine people living with dementia and five family members.
Results: Using enhanced methods and outreach it was possible to adapt the PPIE process so that not only family members and people with milder cognitive difficulties could participate, but also those with more pronounced cognitive problems whose voices are less often heard.
Conclusions: Making creative adaptations is vital in PPIE involving people living with dementia if we wish to develop inclusive forms of PPIE practice. This may, however, raise new ethical issues, which are briefly discussed.National Institute for Health Research. Grant Number: PR-R10-0514-12000
An epidermal-specific role for arginase1 during cutaneous wound repair
Get PDFYesNon-healing wounds are a major area of unmet clinical need remaining problematic to treat. Improved understanding of pro-healing mechanisms is invaluable. The enzyme arginase1 is involved in pro-healing responses with its role in macrophages best characterized. Arginase1 is also expressed by keratinocytes; however, arginase1 function in these critical wound repair cells is not understood. We characterized arginase1 expression in keratinocytes during normal cutaneous repair and reveal de novo temporal and spatial expression at the epidermal wound edge. Interestingly, epidermal arginase1 expression was decreased in both human and murine delayed healing wounds. We therefore generated a keratinocyte specific arginase1-null mouse model (K14-cre;Arg1fl/fl) to explore arginase function. Wound repair, linked to changes in keratinocyte proliferation, migration and differentiation, was significantly delayed in K14-cre;Arg1fl/fl mice. Similarly, using the arginase inhibitor nor-NOHA, human in vitro and ex vivo models further confirmed this finding, revealing the importance of the downstream polyamine pathway in repair. Indeed, restoring the balance in arginase1 activity via addition of putrescine, proved beneficial in wound closure. In summary, we demonstrate that epidermal arginase1 plays a, to our knowledge, previously unreported intrinsic role in cutaneous healing, highlighting epidermal arginase1 and downstream mediators as potential targets for the therapeutic modulation of wound repair
High-isolation antenna array using SIW and realized with a graphene layer for sub-terahertz wireless applications
Get PDFYesThis paper presents the results of a study on developing an effective technique to increase the performance characteristics of antenna arrays for sub-THz integrated circuit applications. This is essential to compensate the limited power available from sub-THz sources. Although conventional array structures can provide a solution to enhance the radiation-gain performance however in the case of small-sized array structures the radiation properties can be adversely affected by mutual coupling that exists between the radiating elements. It is demonstrated here the effectiveness of using SIW technology to suppress surface wave propagations and near field mutual coupling effects. Prototype of 2 × 3 antenna arrays were designed and constructed on a polyimide dielectric substrate with thickness of 125 μm for operation across 0.19-0.20 THz. The dimensions of the array were 20 × 13.5 × 0.125 mm3. Metallization of the antenna was coated with 500 nm layer of Graphene. With the proposed technique the isolation between the radiating elements was improved on average by 22.5 dB compared to a reference array antenna with no SIW isolation. The performance of the array was enhanced by transforming the patch to exhibit metamaterial characteristics. This was achieved by embedding the patch antennas in the array with sub-wavelength slots. Compared to the reference array the metamaterial inspired structure exhibits improvement in isolation, radiation gain and efficiency on average by 28 dB, 6.3 dBi, and 34%, respectively. These results show the viability of proposed approach in developing antenna arrays for application in sub-THz integrated circuits.Ministerio de Ciencia, Innovación y Universidades, Gobierno de España (MCIU/AEI/FEDER, UE) under Grant RTI2018-095499-B-C31, in part by the Innovation Programme under Grant H2020-MSCA-ITN-2016 SECRET-722424, and in part by the U.K. Engineering and Physical Sciences Research Council (EPSRC) under Grant EP/E022936/1
CLEAR - Orthokeratology
No full textNoOrthokeratology (ortho-k) is the process of deliberately reshaping the anterior cornea by utilising specialty contact lenses to temporarily and reversibly reduce refractive error after lens removal. Modern ortho-k utilises reverse geometry lens designs, made with highly oxygen permeable rigid materials, worn overnight to reshape the anterior cornea and provide temporary correction of refractive error. More recently, ortho-k has been extensively used to slow the progression of myopia in children. This report reviews the practice of ortho-k, including its history, mechanisms of refractive and ocular changes, current use in the correction of myopia, astigmatism, hyperopia, and presbyopia, and standard of care. Suitable candidates for ortho-k are described, along with the fitting process, factors impacting success, and the potential options for using newer lens designs. Ocular changes associated with ortho-k, such as alterations in corneal thickness, development of microcysts, pigmented arcs, and fibrillary lines are reviewed. The safety of ortho-k is extensively reviewed, along with an overview of non-compliant behaviours and appropriate disinfection regimens. Finally, the role of ortho-k in myopia management for children is discussed in terms of efficacy, safety, and potential mechanisms of myopia control, including the impact of factors such as initial fitting age, baseline refractive error, the role of peripheral defocus, higher order aberrations, pupil size, and treatment zone size.The CLEAR initiative was facilitated by the BCLA, with financial support by way of Educational Grants for collaboration, publication and dissemination provided by Alcon and CooperVision
A new fractional-order chaotic system with its analysis, synchronization, and circuit realization for secure communication applications
Get PDFYesThis article presents a novel four-dimensional autonomous fractional-order chaotic system (FOCS) with multi-nonlinearity terms. Several dynamics, such as the chaotic attractors, equilibrium points, fractal dimension, Lyapunov exponent, and bifurcation diagrams of this new FOCS, are studied analytically and numerically. Adaptive control laws are derived based on Lyapunov theory to achieve chaos synchronization between two identical new FOCSs with an uncertain parameter. For these two identical FOCSs, one represents the master and the other is the slave. The uncertain parameter in the slave side was estimated corresponding to the equivalent master parameter. Next, this FOCS and its synchronization were realized by a feasible electronic circuit and tested using Multisim software. In addition, a microcontroller (Arduino Due) was used to implement the sug-gested system and the developed synchronization technique to demonstrate its digital applicability in real-world applications. Furthermore, based on the developed synchronization mechanism, a secure communication scheme was constructed. Finally, the security analysis metric tests were investigated through histograms and spectrograms analysis to confirm the security strength of the employed communication system. Numerical simulations demonstrate the validity and possibility of using this new FOCS in high-level security communication systems. Furthermore, the secure communication system is highly resistant to pirate attacks. A good agreement between simulation and experimental results is obtained, showing that the new FOCS can be used in real-world applications
Directional and Isolated UWB-MIMO Antenna Based Uniplanar UWB-FSS Array and T-strip for Bi-static Microwave Imaging: Baggage-Scanner
Get PDFYesThis article presented a novel compact multi-input-multi-output (MIMO) hexagonal monopole antenna with a uniplanar compact frequency-selective-surface (FSS) array for microwave imaging (MWI). The ultra-wideband (UWB) dual-element linear MIMO antenna was designed on the FR4 substrate with 50 Ω coplanar waveguide feed, T-strip isolation, novel numerical calculation, and equivalent circuit analyses. The main issues of realising high-resolution images based on planer UWB antenna for MWI are the low gain, omnidirectional pattern, design size, and mutual coupling of MIMO design. A novel technique was proposed to solve a hybrid issue (mutual coupling) of the MIMO reflected-waves from the FSS array and direct-wave. The uniplanar UWB-FSS unit cell was compacted by combining a square-loop and cross-dipole with a size of 0.095λ×0.095λ. The novel isolated UWB-MIMO antenna and UWB-FSS array (IMAF) were integrated, after investigating the distance between the antenna and FSS. The fabricated IMAF with a stable gain improvement of 4.5 dBi higher than the antenna without FSS, directional radiation pattern, size of 30×73.8×21.6 mm3 observed that a low mutual coupling of -27 dB, and operation bandwidth of 3.0-11.7 GHz. Moreover, a handbag was scanned experimentally via the bi-static approach to detect a small concealed object. The MWI system based on the MIMO antenna with FSS was displayed image resolution of 55% higher than that of MIMO antenna without FSS. The new baggage-scanner approach confirmed that the proposed MIMO antenna with FSS array can lead the humanity for healthy MWI applications