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Almost-Surely Terminating Asynchronous Byzantine Agreement Revisited
No full textThe problem of Byzantine Agreement (BA) is of interest to both distributed computing and cryptography community. Following well-known results from the distributed computing literature, BA problem in the asynchronous network setting encounters inevitable non-termination issues. The impasse is overcome via randomization that allows construction of BA protocols in two flavours of termination guarantee - with overwhelming probability and with probability one. The latter type termed as almost-surely terminating BAs are the focus of this paper. An eluding problem in the domain of almost-surely terminating BAs is achieving a constant expected running time. Our work makes progress in this direction. In a setting with n parties and an adversary with unbounded computing power controlling at most t parties in Byzantine fashion, we present two asynchronous almost-surely terminating BA protocols: With the optimal resilience of t < n/3, our first protocol runs for expected 0(n) time. The existing protocols in the same setting either runs for expected O(n(2)) time (Abraham et al, PODC 2008) or requires exponential computing power from the honest parties (Wang, CoRR 2015). In terms of communication complexity, our construction outperforms all the known constructions that offer almost-surely terminating feature. With the resilience of t < n/3+epsilon for any epsilon > 0, our second protocol runs for expected O(1/epsilon) time. The expected running time of our protocol turns constant when is a constant fraction. The known constructions with constant expected running time either require to be at least 1 (Feldman-Micali, STOC 1988), implying t < n/4, or calls for exponential computing power from the honest parties (Wang, CoRR 2015). We follow the traditional route of building BA via common coin protocol that in turn reduces to asynchronous verifiable secret sharing (AVSS). Our constructions are built on a variant of AVSS that is termed as shunning. A shunning AVSS fails to offer the properties of AVSS when the corrupt parties strike, but allows the honest parties to locally detect and shun a set of corrupt parties for any future communication. Our shunning AVSS with t < n/3 and t < n/3+epsilon guarantee Omega(n) and respectively Omega(ct(2)) conflicts to be revealed when failure occurs. Turning this shunning AVSS to a common coin protocol constitutes another contribution of our paper
Efficient Adaptively Secure Zero-Knowledge from Garbled Circuits
No full textZero-knowledge (ZK) protocols are undoubtedly among the central primitives in cryptography, lending their power to numerous applications such as secure computation, voting, auctions, and anonymous credentials to name a few. The study of efficient ZK protocols for non-algebraic statements has seen rapid progress in recent times, relying on secure computation techniques. The primary contribution of this work lies in constructing efficient UC-secure constant round ZK protocols from garbled circuits that are secure against adaptive corruptions, with communication linear in the size of the statement. We begin by showing that the practically efficient ZK protocol of Jawurek et al. (CCS 2013) is adaptively secure when the underlying oblivious transfer (OT) satisfies a mild adaptive security guarantee. We gain adaptive security with little to no overhead over the static case. A conditional verification technique is then used to obtain a three-round adaptively secure zero-knowledge argument in the non-programmable random oracle model (NPROM). Our three-round protocol yields a proof size that is shorter than the known UC-secure practically-efficient schemes in the short-CRS model with the right choice of security parameters. We draw motivation from state-of-the-art non-interactive secure computation protocols and leveraging specifics of ZK functionality show a two-round protocol that achieves static security. It is a proof, while most known efficient ZK protocols and our three round protocol are only arguments
Real Time Measurement of Deformability Index for Electro-Mechanodiagnostics
No full textWe report a novel microfluidic platform to measure the stiffness of a single cell by evaluating its deformability index through the time information embedded in the electrical impedance data of the cell transit. The deformability index and transit time are two parameters that quantify the stiffness of a single cell passing through a constriction. Conventionally, the deformability index has been measured optically using a high-speed camera, which is expensive, bulky, time-consuming, and thus limits the portability and ease of mechanodiagnostics. Furthermore, the transit time of cell passage is prone to inadvertent flow rate fluctuations. We use Electrical Impedance Spectroscopy combined with a microfluidic channel integrated with an array of coplanar electrodes to evaluate the deformability index of the biological cells. Additionally, measurements of cell impedance during cell transit provides a multi-modal electromechanical signature of individual cells that can be correlated to their health or disease states. The portable and non-invasive method of mechano-phenotyping cell population would make electro-mechanodiagnostics possible
Fabrication of Flexible Superhydrophobic Surface with Complex 3-D Structure by Mechanical Peeling
No full textIn this work, we have demonstrated a simple low-cost process for fabricating flexible PDMS based superhydrophobic surface with complex 3-D shapes by mechanical peeling which can be used in several household and healthcare applications
Critical Evaluation of Relative Importance of Stress and Stress Gradient in Whisker Growth in Sn Coatings
No full textThe role of stress state and stress gradient in whisker growth in Sn coatings electrodeposited on brass is examined. The bulk stress in Sn coatings was measured using a laser-optics-based curvature setup, whereas glancing angle x-ray diffraction was employed to quantify the stress near the surface; this also allowed studying the role of the out-of-plane stress gradient in whisker growth. Both bulk stress and near-surface stress in the Sn coating evolved with time, wherein both were compressive immediately after the deposition, and thereafter while the bulk stress monotonically became more compressive and subsequently saturated with aging at room temperature, the stress near the surface of the Sn coating continually became more tensile with aging. These opposing evolutionary behaviors of bulk and near-surface stresses readily reveals establishment of a negative out-of-plane stress gradient, which is required for the spontaneous growth of whiskers. The importance of the out-of-plane stress gradient was also validated by externally imposing widely different stress states and stress gradients in Sn coatings using a 3-point bending apparatus. Additional whisker growth occurred in the coatings subjected to external tensile stress; however, this was accompanied by a higher negative out-of-plane stress gradient. The results conclusively demonstrate the important role of the negative out-of-plane stress gradient on whisker growth, as compared to only sign and magnitude of stress
Parallelization of Multi-label classification for large data sets
No full textOver the last few years, multi-label learning has received a lot of attention in research and industries. Since a pattern can belong to more than one class at the same time, it is a very challenging task to classify a test pattern. Multi-label classification algorithms while inferring on large data sets take a long time to run. So, there is a growing demand of an effective and efficient method for multi-label classification problems, both in terms of accuracy and speed. We endeavour to improve the performance and accuracy of a multi-label classification algorithm which, given a pattern, can predict the set of labels it belongs to, for large data sets, using parallel computing in a distributed manner. We also reduced the dimensionality of large data sets with very large number of features by removing the redundant features using a feature selection method (Fscore) to improve the accuracy and reduce the time taken for training phase of the multi-label classification algorithm. The result shows the benefits of using parallel processing over the traditional single-node execution, tested over live benchmark multi-label data sets, in terms of both accuracy and speedup of the process
Measurements of properties of the Higgs boson decaying to a W boson pair in pp collisions at s=13TeV
No full textMeasurements of the production of the standard model Higgs boson decaying to a W boson pair are reported. The W + W � candidates are selected in events with an oppositely charged lepton pair, large missing transverse momentum, and various numbers of jets. To select Higgs bosons produced via vector boson fusion and associated production with a W or Z boson, events with two jets or three or four leptons are also selected. The event sample corresponds to an integrated luminosity of 35.9fb �1 , collected in pp collisions at s=13TeV by the CMS detector at the LHC during 2016. Combining all channels, the observed cross section times branching fraction is 1.28 �0.17 +0.18 times the standard model prediction for the Higgs boson with a mass of 125.09GeV. This is the first observation of the Higgs boson decay to W boson pairs by the CMS experiment. © 2019 The Author(s
Automatic Segmentation of Lumen Intima Layer in Transverse Mode Ultrasound Images
No full textWe propose an elliptical active disc technique for the segmentation of common carotid artery lumen intima layer from transverse mode ultrasound images. The segmentation and subsequent outlining problem is posed as one of optimization of a local energy function with respect to the five degrees-of-freedom that characterize the elliptical active disc. Gradient descent technique is used to find the minimum of the energy function with respect to the five parameters that describe the disc. In addition, we use Green's theorem to optimize the computation of the partial derivatives. For automatic initialization of the active disc, we use the normalized crosscorrelation technique. We report results of experimental validation on SPLab, Brno university database, which contains 971 transverse mode ultrasound images of the carotid artery. We achieve accurate carotid artery lumen intima detection in 97.63 of cases. In addition, for lumen intima layer segmentation we achieve an average Dice index of 94.83. © 2018 IEEE
REPRESENTING COMPLEX ANALOGUES USING A FUNCTION MODEL TO SUPPORT CONCEPTUAL DESIGN
No full textAnalogical design has been a long-standing approach to solve engineering design problems. However, it is still unclear as to how analogues should be presented to engineering design in order to maximize the utility of these. The utility is minimal when analogues are complex and belong to other domain (e.g., biology). Prior work includes the use of a function model called SAPPhIRE to represent over 800 biological and engineered systems. SAPPhIRE stands for the entities: States, Actions, Parts, Phenomena, Inputs, oggans, and Effects that together represent the functionality of a system at various levels of abstraction. In this paper, we combine instances of SAPPhIRE model for representing complex systems (also from the biological domain). We use an electric buzzer to illustrate and compare the efficacy of this model in explaining complex systems with that of a well-known model from literature. The use of multiple-instance SAPPhIRE model instances seems to provide a more comprehensive explanation of a complex system, which includes elements of description that are not present in other models, providing an indication as to which elements might have been missing from a given description. The proposed model is implemented in a web-based tool called Idea-Inspire 4.0, a brief introduction of which is also provided
Molecular characterization and morphological description of cryptic haemoproteids in the laughingthrushes (Leiothrichidae) in the western and eastern Himalaya, India version 1; referees: 3 approved
No full textBackground: Laughingthrushes (family: Leiothrichidae) consists of diverse and widespread species found in the Indian subcontinent but there is a lack of information on their avian haemosporidians. Methods: We sampled 231 laughingthrushes of 8 species in the western and eastern Himalaya in India. Using parasite morphology and cytochrome b sequences we describe 2 new Haemoproteus species harbored in 3 species of laughingthrushes and report a case of cryptic speciation. Results: First Haemoproteus lineage TROERY01 (GenBank: KY623720) found in Trochalopteron erythrocephalum (27.47) and Trochalopteron variegatum (2.9) in mid to high altitude tropical forests in the western and eastern Himalaya, was described as Haemoproteus (Parahaemoproteus) leiothrichus n. sp. (Haemosporida: Haemoproteidae). Second Haemoproteus lineage TROERY02 (GenBank: KY623721) described as Haemoproteus (Parahaemoproteus) homoleiothrichus n. sp. (Haemosporida: Haemoproteidae) was found in T. erythrocephalum (2.19) and Trochalopteron lineatum (3.84), albeit in low intensity, only in the western Himalaya. Both H. homoleiothrichus n. sp. and H. leiothrichus n. sp. showed no significant difference in morphological features in blood stages. A genetic divergence of 4.4 along with distinct phylogenetic position indicates that these 2 lineages represent cryptic species. Previously, T. erythrocephalum has been described as an additional host for a morphologically described Haemoproteus timalus in the oriental region. Our described species have several morphological features that are absent in H. timalus. These are, the presence of dumbbell-like shaped mature gametocytes, �arm� like extensions of gametocytes and lateral displacement of nuclei of infected erythrocytes. Illustrations of blood stages of the new species are given, and phylogenetic analysis with morphologically described Haemoproteus species identifies parasites closely related to the 2 described parasites. Conclusions: The lineages described here have been recorded only in the laughingthrushes so far. These are the first parasites to be described with T. erythrocephalum as a type host from the western and eastern Himalaya in India. © 2018 Ishtiaq F et al