Pseudo-Separation for Assessment of Structural Vulnerability of a Network

Based upon the idea that network functionality is impaired if two nodes in a network are sufficiently separated in terms of a given metric, we introduce two combinatorial \emph{pseudocut} problems generalizing the classical min-cut and multi-cut problems. We expect the pseudocut problems will find broad relevance to the study of network reliability. We comprehensively analyze the computational complexity of the pseudocut problems and provide three approximation algorithms for these problems. Motivated by applications in communication networks with strict Quality-of-Service (QoS) requirements, we demonstrate the utility of the pseudocut problems by proposing a targeted vulnerability assessment for the structure of communication networks using QoS metrics; we perform experimental evaluations of our proposed approximation algorithms in this context

Achieving Performance Balance for Dual-Criticality System Based on ARM TrustZone

Many mixed-criticality systems are composed of a RTOS (Real-Time Operating System) and a GPOS (General Purpose Operating System), and we define this as a mixed-timesensitive system. Complexity, isolation, real-time latency, and overhead are the main metrics to design such a mixed-timesensitive system. These metrics may conflict with each other, so it is difficult for them to be consistently optimized. Most existing implementations only optimize with part of the above metrics but not all. As the first contribution, this paper provides a detailed analysis of performance influencing factors which are exerted by various runtime mechanisms of existing mixed-time-sensitive systems. We figure out the difference in performance across system designs such as task switching, memory management, interrupt handling, and resource isolation. We propose the philosophy of utilizing TrustZone characteristics to optimize various mechanisms in mixed-time-sensitive systems. The second contribution of the paper is to propose a Trustzonebased solution - termed TZDKS - for mixed-time sensitive system. Appropriate utilization of TrustZone extensions helps TZDKS to implements (i) virtualization environment for GPOS and RTOS, (ii) high efficiency task switching, memory accessing, interrupt handling and device accessing which are verified by experiments. Therefore, TZDKS can achieve a full-scale balance amongst aforementioned metrics

Modeling Investments in County and Local Roads to Support Agricultural Logistics

Investments in local roads in North Dakota to support agricultural logistics are estimated with a detailed model that predicts flows from 1,406 crop-producing zones to 317 elevators and plants, and forecasts improvements and maintenance costs for paved and unpaved roads. The study finds that (1) the average farm-to-market trip distance has increased from 12 miles in 1980 to 26 miles in 2009, (2) the estimated resurfacing cost per mile for agricultural distribution routes is 40% greater than for non-agricultural routes, and (3) the estimated cost to maintain acceptable service levels on county and local roads is roughly double historical funding levels

Genome-Wide Gene Expression Effects of Sex Chromosome Imprinting in \u3ci\u3eDrosophila\u3c/i\u3e

Imprinting is well-documented in both plant and animal species. In Drosophila, the Y chromosome is differently modified when transmitted through the male and female germlines. Here, we report genome-wide gene expression effects resulting from reversed parent-of-origin of the X and Y chromosomes. We found that hundreds of genes are differentially expressed between adult male Drosophila melanogaster that differ in the maternal and paternal origin of the sex chromosomes. Many of the differentially regulated genes are expressed specifically in testis and midgut cells, suggesting that sex chromosome imprinting might globally impact gene expression in these tissues. In contrast, we observed much fewer Y-linked parent-of-origin effects on genome-wide gene expression in females carrying a Y chromosome, indicating that gene expression in females is less sensitive to sex chromosome parent-of-origin. Genes whose expression differs between females inheriting a maternal or paternal Y chromosome also show sex chromosome parent-of-origin effects in males, but the direction of the effects on gene expression (overexpression or underexpression) differ between the sexes. We suggest that passage of sex chromosome chromatin through male meiosis may be required for wild-type function in F1 progeny, whereas disruption of Y-chromosome function through passage in the female germline likely arises because the chromosome is not adapted to the female germline environment

Genome-Wide Gene Expression Effects of Sex Chromosome Imprinting in Drosophila

Imprinting is well-documented in both plant and animal species. In Drosophila, the Y chromosome is differently modified when transmitted through the male and female germlines. Here, we report genome-wide gene expression effects resulting from reversed parent-of-origin of the X and Y chromosomes. We found that hundreds of genes are differentially expressed between adult male Drosophila melanogaster that differ in the maternal and paternal origin of the sex chromosomes. Many of the differentially regulated genes are expressed specifically in testis and midgut cells, suggesting that sex chromosome imprinting might globally impact gene expression in these tissues. In contrast, we observed much fewer Y-linked parent-of-origin effects on genome-wide gene expression in females carrying a Y chromosome, indicating that gene expression in females is less sensitive to sex chromosome parent-of-origin. Genes whose expression differs between females inheriting a maternal or paternal Y chromosome also show sex chromosome parent-of-origin effects in males, but the direction of the effects on gene expression (overexpression or underexpression) differ between the sexes. We suggest that passage of sex chromosome chromatin through male meiosis may be required for wild-type function in F1 progeny, whereas disruption of Y-chromosome function through passage in the female germline likely arises because the chromosome is not adapted to the female germline environment

Work-In-Progress: : Real-Time RPC for Hybrid Dual-OS System

For the power and space sensitive systems such as automotive/avionic computers, an important trend is isolating and integrating multiple Operating Systems (OSs) in one physical platform, which is named as hybrid multi-OS system. Generally, in a commonly used hybrid dual-OS system, a RTOS (realtime operating system) and a GPOS (general-purpose operating system) are integrated. Cooperation (among the OSs) is a vital feature of a hybrid system to obtain the necessary capabilities, and inter-OS communication is the key. However, it is difficult to satisfy the real-time metrics of inter-OS communication required by the RTOS, due to the uncertainty in communication maintenance and the time-sharing policy of the GPOS. This paper aims to build a time predictable and secure RPC mechanism (i.e., the primary and critical communication unit in a hybrid multi-OS system). Afterwards, a real-time RPC scheme (termed RTRGRPC) is proposed, which is applied to a ready-built TrustZonebased hybrid dual-OS system (i.e., TZDKS). RTRG-RPC achieves accurate time control through three mechanisms: SGI message transforming, interrupt handler RPC servicing, and priorityswapping. Evaluations show that RTRG-RPC can achieve realtime predictability and can also reduce priority inversion

Novel Insights into Orbital Angular Momentum Beams: From Fundamentals, Devices to Applications

It is well-known by now that the angular momentum carried by elementary particles can be categorized as spin angular momentum (SAM) and orbital angular momentum (OAM). In the early 1900s, Poynting recognized that a particle, such as a photon, can carry SAM, which has only two possible states, i.e., clockwise and anticlockwise circular polarization states. However, only fairly recently, in 1992, Allen et al. discovered that photons with helical phase fronts can carry OAM, which has infinite orthogonal states. In the past two decades, the OAM-carrying beam, due to its unique features, has gained increasing interest from many different research communities, including physics, chemistry, and engineering. Its twisted phase front and intensity distribution have enabled a variety of applications, such as micromanipulation, laser beam machining, nonlinear matter interactions, imaging, sensing, quantum cryptography and classical communications. This book aims to explore novel insights of OAM beams. It focuses on state-of-the-art advances in fundamental theories, devices and applications, as well as future perspectives of OAM beams

Variation of Korotkoff stethoscope sounds during blood pressure measurement: Analysis using a convolutional neural network

Korotkoff sounds are known to change their characteristics during blood pressure (BP) measurement, resulting in some uncertainties for systolic and diastolic pressure (SBP and DBP) determinations. The aim of this study was to assess the variation of Korotkoff sounds during BP measurement by examining all stethoscope sounds associated with each heartbeat from above systole to below diastole during linear cuff deflation. Three repeat BP measurements were taken from 140 healthy subjects (age 21 to 73 years; 62 female and 78 male) by a trained observer, giving 420 measurements. During the BP measurements, the cuff pressure and stethoscope signals were simultaneously recorded digitally to a computer for subsequent analysis. Heart beats were identified from the oscillometric cuff pressure pulses. The presence of each beat was used to create a time window (1s, 2000 samples) centered on the oscillometric pulse peak for extracting beat-by-beat stethoscope sounds. A time-frequency two-dimensional matrix was obtained for the stethoscope sounds associated with each beat, and all beats between the manually determined SBPs and DBPs were labeled as ‘Korotkoff’. A convolutional neural network was then used to analyze consistency in sound patterns that were associated with Korotkoff sounds. A 10-fold cross-validation strategy was applied to the stethoscope sounds from all 140 subjects, with the data from ten groups of 14 subjects being analysed separately, allowing consistency to be evaluated between groups. Next, within-subject variation of the Korotkoff sounds analysed from the three repeats was quantified, separately for each stethoscope sound beat. There was consistency between folds with no significant differences between groups of 14 subjects (P = 0.09 to P = 0.62). Our results showed that 80.7% beats at SBP and 69.5% at DBP were analysed as Korotkoff sounds, with significant differences between adjacent beats at systole (13.1%, P = 0.001) and diastole (17.4%, P < 0.001). Results reached stability for SBP (97.8%, at 6th beats below SBP) and DBP (98.1%, at 6th beat above DBP) with no significant differences between adjacent beats (SBP P = 0.74; DBP P = 0.88). There were no significant differences at high cuff pressures, but at low pressures close to diastole there was a small difference (3.3%, P = 0.02). In addition, greater within subject variability was observed at SBP (21.4%) and DBP (28.9%), with a significant difference between both (P < 0.02). In conclusion, this study has demonstrated that Korotkoff sounds can be consistently identified during the period below SBP and above DBP, but that at systole and diastole there can be substantial variations that are associated with high variation in the three repeat measurements in each subject

END-TO-END ENCRYPTION AND DECRYPTION WITHIN A HIERARCHICAL SD-WAN WITH AN IPV6 TRANSPORT

Techniques are presented herein that address a singular pain point in a hierarchical software-defined wide area network (SD-WAN) deployment comprising an Internet Protocol (IP) version 6 (IPv6) transport – end-to-end encryption and decryption. Aspects of the presented techniques leverage the IPv6 address schema to support a new concept that may be referred to herein as a micro-Transport Locator (TLOC) or uTLOC. Under the presented techniques, when an Overlay Management Protocol (OMP) virtual private network (VPN) route is published a next hop may be set to the combination of all of the uTLOCs along a path. Within such a context, each router (along the path) may program a customized action (such as, for example, the shifting of a destination, an insertion into a source, etc.) into a routing table for a uTLOC prefix and then forward a packet to a destination edge without the need for decryption and re-encryption operations in an intermediate border router

Challenges and Opportunities of Self-healing Polymers and Devices for Extreme and Hostile Environments

Engineering materials and devices can be damaged during their service life as a result of mechanical fatigue, punctures, electrical breakdown, and electrochemical corrosion. This damage can lead to unexpected failure during operation, which requires regular inspection, repair, and replacement of the products, resulting in additional energy consumption and cost. During operation in challenging, extreme, or harsh environments, such as those encountered in high or low temperature, nuclear, offshore, space, and deep mining environments, the robustness and stability of materials and devices are extremely important. Over recent decades, significant effort has been invested into improving the robustness and stability of materials through either structural design, the introduction of new chemistry, or improved manufacturing processes. Inspired by natural systems, the creation of self-healing materials has the potential to overcome these challenges and provide a route to achieve dynamic repair during service. Current research on self-healing polymers remains in its infancy, and self-healing behavior under harsh and extreme conditions is a particularly untapped area of research. Here, the self-healing mechanisms and performance of materials under a variety of harsh environments are discussed. An overview of polymer-based devices developed for a range of challenging environments is provided, along with areas for future research