Miracle-dz/UniFAR-FTUs huggingface dataset:
EFFECTIVE APPROXIMATION OF ZERO-VARIANCE SIMULATION IN A RELIABILITY SETTING

For every stochastic simulation model, there is in theory a way of changing the probability laws that drive the system so that the resulting IS estimator has zero variance. This optimal estimation scheme is generally impractical to implement, but it can be possible to approximate it in an effective way. When the model is described by a discretetime Markov chain that evolves up to some random stopping time, the zero-variance change of measure can be written exactly in terms of a value function that gives the expected cost-to-go from any state of the chain, so it can be approximated by approximating this value function. We detail this approach and show how it can be effectively used to estimate the reliability of a highly-reliable multicomponent system with Markovian behavior. In our implementation, we start with a very simple crude approximation, use it in a first-order IS scheme to obtain a better approximation at a few selected states, interpolate in between, and use this interpolation in our final (second-order) IS scheme. In numerical illustrations, our approach outperforms the popular IS heuristics previously proposed for this class of problems.
Magnetic resonance electrical impedance tomography (MREIT) for high-resolution conductivity imaging

Cross-sectional imaging of an electrical conductivity distribution inside the human body has been an active research goal in impedance imaging. By injecting current into an electrically conducting object through surface electrodes, we induce current density and voltage distributions. Based on the fact that these are determined by the conductivity distribution as well as the geometry of the object and the adopted electrode configuration, electrical impedance tomography (EIT) reconstructs cross-sectional conductivity images using measured current–voltage data on the surface. Unfortunately, there exist inherent technical difficulties in EIT. First, the relationship between the boundary current–voltage data and the internal conductivity distribution bears a nonlinearity and low sensitivity, and hence the inverse problem of recovering the conductivity distribution is ill posed. Second, it is difficult to obtain accurate information on the boundary geometry and electrode positions in practice, and the inverse problem is sensitive to these modeling errors as well as measurement artifacts and noise. These result in EIT images with a poor spatial resolution. In order to produce high-resolution conductivity images, magnetic resonance electrical impedance tomography (MREIT) has been lately developed. Noting that injection current produces a magnetic as well as electric field inside the imaging object, we can measure the induced internal magnetic flux density data using an MRI scanner. Utilization of the internal magnetic flux density is the key idea of MREIT to overcome the technical difficulties in EIT. Following original ideas on MREIT in early 1990s, there has been a rapid progress in its theory, algorithm and experimental techniques. The technique has now advanced to the stage of human experiments. Though it is still a few steps away from routine clinical use, its potential is high as a new impedance imaging modality providing conductivity images with a spatial resolution of a few millimeters or less. This paper reviews MREIT from the basics to the most recent research outcomes. Focusing on measurement techniques and experimental methods rather than mathematical issues, we summarize what has been done and what needs to be done. Suggestions for future research directions, possible applications in biomedicine, biology, chemistry and material science are discussed.
The Influence of Vertebral Fracture on the Functional Disability of Patients with Rheumatoid Arthritis

The aim of the present study was to identify the influence of vertebral fracture (VF) on the functional disability in patients with rheumatoid arthritis (RA). This study consecutively enrolled 100 female patients aged 50 yr or older with RA. All participants underwent lateral imaging of the thoracolumbar spine by simple radiography to identify any VFs. They also completed questionnaires via interview regarding demographics, medical history, and disease outcomes including functional disability. We used univariate analysis to evaluate associations between functional disability and VF, and made multivariate logistic regression models to test independent effect of the presence of VF, the number of VFs, and the severity of VF on functional disability. Among the 100 RA patients, 47 had at least one VF, but 34 of them were asymptomatic that they had experienced a fracture. The multiple VFs ≥ 3 (OR, 8.95; 95% CI, 1.77-44.15, P = 0.01) and moderate or severe VF (OR, 3.38; 95% CI, 1.26-9.04, P = 0.02) were related to disability in univariate analysis. The multiple VFs ≥ 3 (OR, 6.13; 95% CI, 1.02-36.94, P = 0.048) was associated with functional disability of RA patients after adjusting various confounders and it was mainly in walking and arising. The VF might be an important factor which affects functional disability in RA patients. Graphical Abstract
Meiosis-activating sterol protects oocytes from precocious chromosome segregation.

BACKGROUND Follicular fluid meiosis-activating sterol (FF-MAS) overcomes hypoxanthine (HX)-mediated meiotic arrest in mammalian oocytes. METHODS In order to determine whether chromosome segregation was normal in oocytes matured in FF-MAS, the development, chromosomal constitution and chromosome alignment was analysed in spontaneously matured as well as HX-arrested mouse oocytes cultured in the absence or presence of FF-MAS. RESULTS FF-MAS-induced meiotic maturation was significantly less effective compared with spontaneous maturation in supporting cytokinesis ( approximately 40 and approximately 90% polar body formation respectively). The majority of oocytes stimulated by FF-MAS to overcome the HX block developed to metaphase II (MII), but 23.4% of meiosis II oocytes were diploid. Chromosomes were well aligned on the spindle, and hyperploidy was low in spontaneously matured oocytes and HX-arrested oocytes cultured with or without FF-MAS. Unexpectedly, almost 40% of spontaneously matured MII oocytes contained chromatids/monads. Precocious loss of chromatid cohesion was significantly reduced in spontaneously matured as well as HX-arrested oocytes cultured in the presence of FF-MAS but not lanosterol. CONCLUSIONS FF-MAS induces full nuclear maturation to MII, and chromosomes segregate with high fidelity. However, in delayed FF-MAS-stimulated meiotic maturation, anaphase I may occur in the absence of cytokinesis. FF-MAS appears to protect mammalian oocytes from precocious chromatid segregation.
Tax morale and institutional theory: a systematic review

Purpose The purpose of this paper is to conduct a systematic review of the factors that shape tax morale. A large range of random explanatory variables identified in the literature as determinants of tax morale are synthesised and structured by drawing inspiration from the institutional theory. Design/methodology/approach To do this, a systematic search has been conducted using a library catalogue which provides access to more than 400 databases. Findings The finding is that the institutional theory provides a suitable theoretical basis to explore tax morale. Indeed, all the factors until now identified as determinants of tax morale (except the control variables/socio-demographic characteristics) can be categorised either as belonging to formal institutions or to informal institutions. The most salient factor is trust, with both vertical and horizontal trust positively related to tax morale. Research limitations/implications The outcome is a call for a more nuanced understanding of not only the effect of formal and informal institutions on tax morale but also how formal and informal institutions interact and alter each other and, consequently, affect tax morale. Practical implications The paper seeks to encourage governments to start recognising that as low tax morale arises when a gap exists between formal and informal institutions, they need to design policy measures aimed to reduce this gap, rather than persisting with deterrence measures. Originality/value This is the first systematic review of the factors that influence tax morale using an institutionalist lens.
Image retrieve using visual attention weight model

In order to improve the precision of image retrieve, this paper proposes an image retrieve method base on visual attention weight model. This method is based on multiple visual attention mechanism of human's eye. By computing the visual attention weight of image regions, we can obtain the focus region of the image. Then we use SVM classification retrieve based on focus region. The experiment shows that the new model can recognize the focus region of the image precisely and improve precision of image retrieve.
Complete genome sequence and phenotype microarray analysis of Cronobacter sakazakii SP291: a persistent isolate cultured from a powdered infant formula production facility

Outbreaks of human infection linked to the powdered infant formula (PIF) food chain and associated with the bacterium Cronobacter, are of concern to public health. These bacteria are regarded as opportunistic pathogens linked to life-threatening infections predominantly in neonates, with an under developed immune system. Monitoring the microbiological ecology of PIF production sites is an important step in attempting to limit the risk of contamination in the finished food product. Cronobacter species, like other microorganisms can adapt to the production environment. These organisms are known for their desiccation tolerance, a phenotype that can aid their survival in the production site and PIF itself. In evaluating the genome data currently available for Cronobacter species, no sequence information has been published describing a Cronobacter sakazakii isolate found to persist in a PIF production facility. Here we report on the complete genome sequence of one such isolate, Cronobacter sakazakii SP291 along with its phenotypic characteristics. The genome of C. sakazakii SP291 consists of a 4.3-Mb chromosome (56.9% GC) and three plasmids, denoted as pSP291-1, [118.1-kb (57.2% GC)], pSP291-2, [52.1-kb (49.2% GC)], and pSP291-3, [4.4-kb (54.0% GC)]. When C. sakazakii SP291 was compared to the reference C. sakazakii ATCC BAA-894, which is also of PIF origin, the annotated genome data identified two interesting functional categories, comprising of genes related to the bacterial stress response and resistance to antimicrobial and toxic compounds. Using a phenotypic microarray (PM), we provided a full metabolic profile comparing C. sakazakii SP291 and the previously sequenced C. sakazakii ATCC BAA-894. These data extend our understanding of the genome of this important neonatal pathogen and provides further insights into the genotypes associated with features that can contribute to its persistence in the PIF environment.
Supplementary material from "Thermal decomposition characteristics of foundry sand for cast iron in nitrogen atmosphere"

Sand casting, currently the most popular approach to the casting production, has wide adaptability and low cost. The thermal decomposition characteristics of foundry sand for cast iron were determined for the first time in this study. Thermogravimetry was monitored by simultaneous thermal analyser to find that no obvious oxidation or combustion reaction in the foundry sand; the thermal decomposition degree increased as the heating rate increased. There was an obvious endothermic peak at about 846 K due to the transition of quartz from β to α phase. A novel technique was established to calculate the starting temperature of volatile emission in determining the volatile release parameter of foundry sand for cast iron. Foundry sand does not readily evaporate because its volatile content is only about 2.68 wt% and its main components have high-temperature stability. The thermal decomposition kinetics parameters of foundry sand, namely activation energy and pre-exponential factor , were obtained under kinetics theory. The activation energy of foundry sand for cast iron was small, mainly due to the wide temperature range of thermal decomposition in the foundry sand.
Analyzing human fingertip usage in dexterous precision manipulation: Implications for robotic finger design

Designing robot hands for dexterous precision manipulation involves many complex tradeoffs in order to optimize hand performance. While many studies focus on overall hand kinematics, far fewer consider tradeoffs in the design of the robotic finger surfaces themselves. Our present work uses 3.8 total hours of precision manipulation from 19 participants to look at the fingertip surfaces used while moving a sphere through as much of the feasible position workspace as possible. Fingertip surface use is estimated by measuring the relative orientation changes between a high-resolution 6DOF sensor mounted on the fingernails of the fingers and in the object being manipulated, indicating to what extent the object has been “rolled” onto the sides of the fingers. The results show significant lateral use of the index and middle fingers, and also show that the side surface of the index finger is used much more in two-finger manipulation than three finger manipulation. The lateral fingertip usage suggests that robot finger designs could also benefit from enabling lateral surface use. The lateral middle finger use also suggests that fingers can be effectively used as passive supports to supply forces in directions that may not be actively controlled. We anticipate these results should be useful especially for robotic and prosthetic hand design, but also in other fields such as rehabilitation or haptic interface design.
Pairing SDN with network virtualization: The network hypervisor placement problem

A network virtualization hypervisor for Software Defined Networking (SDN) is the essential component for the realization of virtual SDN networks (vSDNs). Virtualizing software defined networks enables tenants to bring their own SDN controllers in order to individually program the network control of their virtual SDN networks. A hypervisor acts as an intermediate layer between the tenant SDN controllers and their respective virtual SDN networks. The hypervisor consists of the network functions that are necessary for virtualization, e.g., translation or isolation functions. For scalability, the hypervisor can be realized via multiple physically distributed instances each hosting the needed virtualization functions. In this way, the physical locations of the instances, which realize the hypervisor, may impact the overall performance of the virtual SDN networks. Network virtualization adds new dimensions to the general SDN controller placement problem. This paper initiates the study of the network hypervisor placement problem (HPP). The HPP targets the following questions: How many hypervisor instances are needed? Where should the hypervisor instances be placed in the network? For our study of the HPP, we provide a mathematical model that solves the HPP for a case where node and link capacity constraints are not considered. We propose four latency metrics for optimizing placement solutions based on our model for vSDNs. Covering a real network topology, our evaluation quantifies the trade-offs between the new metrics when used as objectives. Furthermore, we analyze the impact of the physical network topology on the optimization results and identify potentials for improvement, e.g., in terms of runtime.
A New Option Pricing Model for Stocks in Uncertainty Markets

This paper presents a type of stock models for uncertain markets by using uncertainty theory. Firstly, a brief history of stock models and some methodologies are reviewed. Next, some useful concepts and properties about uncertain process are recalled. Then, a stock model for uncertain markets is formulated by the tool of uncertain differential equation. Some option pricing formulas on the proposed uncertain stock model are investigated and some numerical calculations are illustrated. Finally, some remarks are made in the concluding section.
Wrapped fluxbranes

We consider the construction of ﬂuxbranes in certain curved geometries, generalizing the familiar construction of the Melvin ﬂuxtube as a quotient of ﬂat space. The resulting conﬁgurations correspond to ﬂuxbranes wrapped on cycles in curved spaces. The non-trivial transverse geometry leads in some instances to solutions with asymptotically constant dilaton proﬁles. We describe explicitly several supersymmetric solutions of this kind. The solutions inherit some properties from their ﬂat space cousins, like ﬂux periodicity. Interestingly type IIA/0A ﬂuxbrane duality holds near the core of these ﬂuxbranes, but does not persist in the asymptotic region, precisely where it would contradict perturbative inequivalence of IIA/0A theories.
The Angular Three-Point Correlation Function in the Quasi-linear Regime

We calculate the normalized angular three-point correlation function (3PCF), q, as well as the normalized angular skewness, s3, assuming the small-angle approximation, for a biased mass distribution in flat and open cold dark matter (CDM) models with Gaussian initial conditions. The leading-order perturbative results incorporate the explicit dependence on the cosmological parameters, the shape of the CDM transfer function, the linear evolution of the power spectrum, the form of the assumed redshift distribution function, and linear and nonlinear biasing, which may be evolving. Results are presented for different redshift distributions, including that appropriate for the APM Galaxy Survey, as well as for a survey with a mean redshift of ≃ 1 (such as the VLA FIRST Survey). Qualitatively, many of the results found for s3 and q are similar to those obtained in a related treatment of the spatial skewness and 3PCF, such as a leading-order correction to the standard result for s3 in the case of nonlinear bias (as defined for unsmoothed density fields), and the sensitivity of the configuration dependence of q to both cosmological and biasing models. We show that since angular correlation functions (CFs) are sensitive to clustering over a range of redshifts, the various evolutionary dependences included in our predictions imply that measurements of q in a deep survey might better discriminate between models with different histories, such as evolving versus nonevolving bias, that can have similar spatial CFs at low redshift. Our calculations employ a derived equation, valid for open, closed, and flat models, to obtain the angular bispectrum from the spatial bispectrum in the small-angle approximation.
High-performance telepointers

Although telepointers are valuable for supporting real-time collaboration, they are rarely seen in commercial groupware applications that run on the Internet. One reason for their absence is that current telepointer implementations perform poorly on real-world networks with varying traffic, congestion, and loss. In this paper, we report on a new implementation of telepointers (HPT) that is designed to provide smooth, timely, and accurate telepointers in real-world groupware: on busy networks, on cable and dialup connections, and on wireless channels. HPT maintains performance at usable levels with a combination of techniques from multimedia and distributed systems research, including UDP transport, message compression, motion prediction, adaptive rate control, and adaptive forward error correction. Although these techniques have been seen before, they have never been combined and tailored to the specific requirements of telepointers. Tests of the new implementation show that HPT provides good performance in a number of network situations where other implementations do not work at all - we can provide usable telepointers even over a lossy 28K modem connection. HPT sets a new standard for telepointers, and allows designers to greatly improve the support that groupware provides for real-time interaction over distance.
A video-based traffic monitoring system based on the novel gradient-edge and detectionwindow techniques

This paper presents the novel algorithms for a video-based traffic monitoring system. In the video-based traffic monitoring system, the vehicle detection and traffic parameter extraction are the main processes of the traffic monitoring system. The vehicles will be extracted in the first process, and the result will be fed as an input to the next process in order to evaluate the traffic information. The proposed vehicle detection technique employs the gradient-based adaptive threshold estimation (GATE) to estimate the proposed threshold values, which are automatically adapted to the changes of various illumination conditions throughout the day. In addition, the horizontal moving edge detection (HMED) is proposed for traffic parameter extraction. The experimental results indicate that the proposed GATE algorithm yield the proper threshold value for each illuminated condition in the vehicle detection process while the proposed HMED algorithm can effectively resolve the uneven edge density of vehicles.
A robot-walk-based collaborative algorithm for target tracking in ad hoc sensor networks

Recent advances in processor, memory and radio technology have enabled cheap nodes capable of sensing, communication and processing. Networks of distributed micro sensors are rapidly emerging as a feasible solution to a wide range of data gathering applications. This work develops a framework for using a wireless ad hoc network of distributed sensors for detection and tracking of moving objects. Each sensor can monitor a wide variety of ambient conditions in other to detect the presence of target. We first propose algorithms which can lead a mobile sensor (or mobile sensors) to reach the exact position of the object which is not moving. We generalize this approach for target tracking using collaborative sensors.
A hierarchical approach of Speech Emotion Recognition based on entropy of enhanced wavelet coefficients

This paper presents a hierarchical Speech Emotion Recognition method, where the speaker-independent emotional features are derived from the Teager energy (TE) operated wavelet coefficients of speech signal. The detail as well as approximate Wavelet coefficients enhanced by TE operation is used to compute entropy. Entropy values of TE operated detail and approximate wavelet coefficients reduce feature dimension, forming an effective feature vector for distinguishing different emotions when fed to a Euclidean distance based classifier in a hierarchical process. Detail simulations are carried on EMO-DB German speech emotion database containing four class emotions, such as angry, happy, sad and neutral. Simulation results show that the proposed hierarchical emotion recognition method gives quite satisfactory four-class emotion recognition performance, yet demonstrates a significant increase in versatility through its propensity for speaker independence with lower computation.
A Basis for Repeated Motifs in Pattern Discovery and Text Mining

We present a new notion of basis that is able to generate the repeated motifs (possibly exponential in number) that appear at least twice with don't care symbols in a string of length n over an alphabet . Our basis has some interesting features such as being (a) a subset of the previously de ned bases, (b) truly linear as its motifs are less than n in number and appear in the string for a total of 2n times at most; (c) symmetric as the basis of the reversed string is the reverse of the basis; (d) computable in polynomial time, namely, in O(n log n log jj) time.