Miracle-dz/UniFAR-FTUs huggingface dataset:
The effect of high voltage fields on epoxy laminates

This thesis describes the characterisation of epoxy/glass fibre composite material before and progressively through electrical and thermal ageing. Glass fibre reinforced epoxy (GFRE) material is used in pressboard transformers for optical telecommunication systems, typically at voltages between 1 and 2kV. The material was characterised by means of space charge measurements using the Pulsed Electroacoustic (PEA) technique, Dielectric response, Dynamic Mechanical Analysis (DMA), Differential Scanning Calorimetry (DSC), and Scanning Electronic Microscopy (SEM). An ageing programme was set up to follow the thermal and electrical ageing (at DC fields) of the GFRE by the same means. The results show a q-dc transport process with an activation energy of 1.1eV. The qdc process is associated with a charge transport process on the surface of the fibres. The results for the aged samples show delamination and debonding between the epoxy and the glass fibre at the glass epoxy interface. The delamination creates free volumes and voids which lead to partial discharge and hence failure. Electrical ageing can be characterised in term of dielectric, PEA, and DSC responses. Thermal ageing does not produce the same effect as electrical ageing. The samples that were only thermally aged behave in the same way as un-aged samples.
Building software agents to assist teaching in distance learning environments

This paper reports on the implementation and realization of software agents as teaching assistants in the distance learning environment. The software agent we built is able to extract run-time information about students' learning progress and their behavior when interacting with the course Web, to aggregate the information, and then to send emails to report its duties to the academic staff. Whenever necessary and appropriate, the software agent can also send emails to tutors and students for timely alerts and advice. With the software agent working as a teaching assistant, the academic staff can delegate many information processing jobs, increase the efficiency of course coordination, and keep close communication with students.
The Importance of Landscape Elements for Bat Activity and Species Richness in Agricultural Areas

Landscape heterogeneity is regarded as a key factor for maintaining biodiversity and ecosystem function in production landscapes. We investigated whether grassland sites at close vicinity to forested areas are more frequently used by bats. Considering that bats are important consumers of herbivorous insects, including agricultural pest, this is important for sustainable land management. Bat activity and species richness were assessed using repeated monitoring from May to September in 2010 with acoustic monitoring surveys on 50 grassland sites in the Biosphere Reserve Schorfheide-Chorin (North-East Germany). Using spatial analysis (GIS), we measured the closest distance of each grassland site to potentially connecting landscape elements (e.g., trees, linear vegetation, groves, running and standing water). In addition, we assessed the distance to and the percent land cover of forest remnants and urban areas in a 200 m buffer around the recording sites to address differences in the local landscape setting. Species richness and bat activity increased significantly with higher forest land cover in the 200 m buffer and at smaller distance to forested areas. Moreover, species richness increased in proximity to tree groves. Larger amount of forest land cover and smaller distance to forest also resulted in a higher activity of bats on grassland sites in the beginning of the year during May, June and July. Landscape elements near grassland sites also influenced species composition of bats and species richness of functional groups (open, edge and narrow space foragers). Our results highlight the importance of forested areas, and suggest that agricultural grasslands that are closer to forest remnants might be better buffered against outbreaks of agricultural pest insects due to higher species richness and higher bat activity. Furthermore, our data reveals that even for highly mobile species such as bats, a very dense network of connecting elements within the landscape is beneficial to promote activity in open areas and thus assure vital ecosystem function in agricultural landscapes.
Folic Acid Supplementation During Early Pregnancy and the Risk of Gestational Hypertension and Preeclampsia

Emerging evidence has suggested that folic acid–containing multivitamins may markedly reduce the risk of gestational hypertension or preeclampsia. We examined whether maternal supplementation with folic acid alone during early pregnancy can prevent the occurrence of gestational hypertension and preeclampsia. The data are from a large population-based cohort study established to evaluate the effectiveness of the campaign to prevent neural tube defects with folic acid supplementation in China. We selected participants who were registered in 2 southern provinces, had exact information on folic acid use, and were not affected by chronic hypertension or diabetes mellitus before 20 weeks gestation. A logistic regression model was used to adjust for the effects of the main potential confounders, including age, body mass index, education, occupation, parity, and multiple births. The study size had 99.9% power (&agr;=0.05) to detect a decrease of 10% over the unexposed rate of 9.4% for gestational hypertension. Among the 193 554 women (47.9% took folic acid, 52.1% did not), the overall incidence of gestational hypertension and preeclampsia was 9.5% and 2.5%, respectively. The incidence of gestational hypertension and preeclampsia was 9.7% and 2.5% for women who took folic acid, and 9.4% and 2.4% for women who did not use it. The adjusted risk ratio associated with folic acid use was 1.08 (95% confidence interval, 1.04–1.11) for gestational hypertension and 1.11 (95% confidence interval, 1.04–1.18) for preeclampsia. Our findings suggest that daily consumption of 400 &mgr;g folic acid alone during early pregnancy cannot prevent the occurrence of gestational hypertension and preeclampsia.
THE rdgB GENE OF DROSOPHILA: A LINK BETWEEN VISION AND OLFACTION

otal (ota = olfactory trap abnormal), an X–linked mutation of Drosophila isolated by virtue of abnormal olfactory behavior, is shown to be an allele of rdgB (retinal degeneration B), a gene required for normal visual system physiology. rdgB function is shown to be necessary for olfactory response of both adult files and larvae, which have distinct olfactory systems. Electrophysiological recordings from the adult antenna indicate that rdgB is required for normal response in the peripheral olfactory system: some rdgB mutants show a delayed return to the resting potential following stimulation with ethyl acetate vapor. These results indicate that rdgB is required for both visual and olfactory physiology, and they suggest that visual and olfactory transduction may share at least one common molecular step in Drosophila.
Extended static checking for haskell

Program errors are hard to detect and are costly both to programmers who spend significant efforts in debugging, and to systems that are guarded by runtime checks. Extended static checking can reduce these costs by helping to detect bugs at compile-time, where possible. Extended static checking has been applied to objectoriented languages, like Java and C#, but it has not been applied to a lazy functional language, like Haskell. In this paper, we describe an extended static checking tool for Haskell, named ESC/Haskell, that is based on symbolic computation and assisted by a few novel strategies. One novelty is our use of Haskell as the specification language itself for pre/post conditions. Any Haskell function (including recursive and higher order functions) can be used in our specification which allows sophisticated properties to be expressed. To perform automatic verification, we rely on a novel technique based on symbolic computation that is augmented by counter-example guided unrolling. This technique can automate our verification process and be efficiently implemented.
Borated polyethylene - fire properties and other issues

The scope and objective of this work was to evaluate and determine fire properties for a material that will be used for radiation shielding at the research centre. Traditionally two materials, borated paraffin and borated polyethylene, are used for radiation shielding at neutron-based research laboratories. Since base paraffin and base polyethylene are known as combustible materials with a high energy content it is of great interest to determine the actual fire properties of the borated versions.
Modeling parallel operating PWM DC/DC power supplies

The control objective of a single operating PWM (pulse-width-modulated) DC/DC (direct current-to-direct current) power supply is to maintain the output voltage close to the reference. In the case of parallel operating power supplies, the control objective is enriched with the demand of keeping the power distribution between the units close to a specified pattern. The paper suggests a model for parallel operating DC/DC converters. The physical meaning of the parameters of the model are discussed. Finally, the paper suggests a structured model uncertainty description based on measurements, simulations, and "experience". >
Discourse Cues for Broadcast News Segmentation

This paper describes the design and application of time-enhanced, finite state models of discourse cues to the automated segmentation of broadcast news, We describe our analysis of a broadcast news corpus, the design of a discourse cue based story segmentor that builds upon information extraction techniques, and finally its computational implementation and evaluation in the Broadcast News Navigator (BNN) to support video news browsing, retrieval, and summarization.
Contemporary Approaches to the Histogram Modification Based Data Hiding Techniques

The main objective of this chapter is to present the contemporary approaches to the steganography/data hiding applications, which are based on image histogram modifications. An image histogram is a type of histogram acting as a graphical representation of the tonal distribution in a digital image. The stego images that are produced by using such data hiding techniques are inherently robust against main geometrical attacks such as rotation, scattered tiles and warping, as well as other main attacks. An up-to-date method and its example application to the latest histogram modification based steganography methods and its results are presented in detail and compared to those of the classical ones in the following sections.
An unsupervised language model adaptation based on keyword clustering and query availability estimation

Language model adaptation using text data downloaded from the WWW is an efficient way to train a topic-specific LM. We are developing an unsupervised LM adaptation method using data in the Web. The one key point of unsupervised Web-based LM adaptation is how to select keywords to compose the search query. In this paper, we propose a new method of selecting keywords from keyword candidates, which uses a keyword clustering technique based on word similarities. The other key point is how to determine the number of downloaded pages for each query. In this paper we propose a method to estimate "a query availability," which is based on a small number of downloaded Web pages. The experimental result showed that the determination of downloaded pages using the query availability was effective than the conventional methods that determined the number of pages empirically.
Dichotomous or categorical response? Analysing self-rated health and lifetime social class.

BACKGROUND Self-rated health is a commonly used measure of health status, usually having three to five categories. The measure is often collapsed into a dichotomous variable of good versus less than good health. This categorization has not yet been justified. METHODS Using data from the 1958 British birth cohort, we examined the relationship between socioeconomic conditions, indicated by occupational class at four ages, and self-rated health. Results obtained for a dichotomous variable using logistic regression were compared with alternative methods for ordered categorical variables including polytomous regression, cumulative odds, continuation ratio and adjacent categories models. RESULTS AND CONCLUSIONS Findings concerning the relationship between socioeconomic position and self-rated health yielded by a logistic regression model were confirmed by alternative statistical methods which incorporate the ordered nature of self-rated health. Similarity of results was found regarding size and significance of main effects, type of association and interactive effects.
Multiuser Two-Way Relaying Schemes for UWB Communication

In this paper, we propose multiuser two-way relaying strategies for pairwise internode communication in a network consisting of ultrawideband transceivers with limited signal processing capability, via a central relay unit. We propose reducing the complexity associated with the design of filters at the relay by using pre/post-rake processing in conjunction with optimized filtering at the relay. Two relaying strategies relevant to multipath fading channels, namely, detect-and-forward and filter-and-forward with self-interference cancelation, are considered. For both methods, we start with a convex optimization problem formulation with closed-form solutions, then extend the design to the more general case, which is a nonconvex problem, and use an alternating optimization algorithm to solve the design problems. Furthermore, for both design schemes, widely linear design formulations are devised. The presented numerical results demonstrate the capability of the proposed design schemes in establishing a reliable communication link between nodes with limited signal processing power and in the absence of a direct link.
Synergetic regulation of translational reading-frame switch by ligand-responsive RNAs in mammalian cells

Distinct translational initiation mechanisms between prokaryotes and eukaryotes limit the exploitation of prokaryotic riboswitch repertoire for regulatory RNA circuit construction in mammalian application. Here, we explored programmed ribosomal frameshifting (PRF) as the regulatory gene expression platform for engineered ligand-responsive RNA devices in higher eukaryotes. Regulation was enabled by designed ligand-dependent conformational rearrangements of the two cis-acting RNA motifs of opposite activity in -1 PRF. Particularly, RNA elements responsive to trans-acting ligands can be tailored to modify co-translational RNA refolding dynamics of a hairpin upstream of frameshifting site to achieve reversible and adjustable -1 PRF attenuating activity. Combined with a ligand-responsive stimulator, synthetic RNA devices for synergetic translational-elongation control of gene expression can be constructed. Due to the similarity between co-transcriptional RNA hairpin folding and co-translational RNA hairpin refolding, the RNA-responsive ligand repertoire provided in prokaryotic systems thus becomes accessible to gene-regulatory circuit construction for synthetic biology application in mammalian cells.
An Application of First-Order Logic to The Study of Recognizable Languages

A variation of first-order logic with variables for exponents is developed to solve some problems in the setting of recognizable languages on the free monoid, accommodating operators such as product, bounded shuffle and reversion. Restricting the operators to powers and product, analogous results are obtained for recognizable languages of an arbitrary finitely generated monoid M, in particular for a free inverse monoid of finite rank. As a consequence, it is shown to be decidable whether or not a recognizable subset of M is pure or p-pure.
Impaired pulmonary diffusion during exercise in patients with chronic heart failure.

BACKGROUND Pulmonary diffusion is impaired at rest in patients with chronic heart failure (CHF) and has been implicated in the generation of symptoms and exercise intolerance. The aim of this study was to determine whether pulmonary diffusion is impaired during exercise in CHF, to examine its relationship to pulmonary blood flow, and to consider its functional significance in relation to metabolic gas exchange. METHODS AND RESULTS Carbon monoxide transfer factor (TLCO) and pulmonary blood flow (Q(C)) were measured by a rebreathe technique at rest and during steady-state cycling at 30 W in 24 CHF patients and 10 control subjects. Both patients and control subjects were able to raise TLCO and Q(C) during exercise. However, the patient group had a lower diffusion for a given blood flow (TLCO/Q(C)) both at rest (3.6+/-0.16 and 4.8+/-0.23 mL x L(-1) x mm Hg(-1); P<0.001) and during exercise (2.8+/-0.16 and 3.4+/-0.13 mL x L(-1) x mm Hg(-1) for CHF patients and control subjects, respectively; P<0.05). TLCO/Q(C) was related to the ventilatory equivalent for carbon dioxide (VEVCO(2)) production at 30 W (TLCO/Q(c) versus VEVCO(2), r = -0.58, P<0.01) and to peak exercise oxygen consumption measured during a progressive test (TLCO/Qc versus VO(2peak), r = 0.57, P<0.01) in these patients. CONCLUSIONS Patients with CHF are able to recruit reserves of TLCO and Q(C) during exercise. However, the TLCO/Q(C) ratio is consistently impaired in these patients and relates to both exercise hyperpnea and peak exercise oxygen consumption. Whether this impairment in alveolar gas exchange is reversible in CHF and therefore is a potential target for therapy has yet to be determined.
Maintenance schedule optimization based on failure probability distribution

Organizations related to infrastructure, such as utilities and railway companies, manage a large number of facilities, the failure of which can have a huge impact on society. The cost of maintaining these facilities is a combination of regular maintenance costs and urgent recovery costs. Generally, the urgent costs are much higher than regular costs. Regular maintenance work should result in fewer sudden failures, and thus reduce these urgent costs. However, if the regular maintenance is too frequent, its cost becomes too high. Therefore, it is important to balance the regular and urgent costs to minimize the overall maintenance cost. We propose a maintenance schedule optimization method based on the failure probability distribution of the facilities. The total cost is mathematically modeled, with the regular maintenance schedule included via decision variables and the occurrence of failures modeled as stochastic variables. The stochastic total maintenance costs are evaluated using a Monte Carlo method, and a genetic algorithm is employed to optimize the maintenance schedule. The proposed method is evaluated using data provided by a Japanese railway company, and our results confirm that the method produces an excellent maintenance schedule. A statistical test shows there is a significant difference between the proposed and conventional methods.
Wideband direction of arrival estimation based on fourth-order cumulants

Based on MUSIC (MUltiple SIgnal Classification) algorithm and CSM (Coherent Signal- subspace Method), a DOA estimation method of wideband signals has been proposed in this paper. At first, the output covariance matrix is formed based on the fourth-order cumulants using the relation between the fourth-order and the covariance. And then using the projector operator to form focusing matrix and estimate the DOA of wideband signals with focused covariance matrix and MUSIC algorithm. This algorithm can suppress Gaussian noise to improve the precision of DOA estimation. It does not need pre-estimation of DOA in focusing processing to improve the speed of the algorithm.
MinimaLT: minimal-latency networking through better security

MinimaLT is a new network protocol that provides ubiquitous encryption for maximal confidentiality, including protecting packet headers. MinimaLT provides server and user authentication, extensive Denial-of-Service protections, privacy-preserving IP mobility, and fast key erasure. We describe the protocol, demonstrate its performance relative to TLS and unencrypted TCP/IP, and analyze its protections, including its resilience against DoS attacks. By exploiting the properties of its cryptographic protections, MinimaLT is able to eliminate three way handshakes and thus create connections faster than unencrypted TCP/IP.
Error bounds from extra-precise iterative refinement

We present the design and testing of an algorithm for iterative refinement of the solution of linear equations where the residual is computed with extra precision. This algorithm was originally proposed in 1948 and analyzed in the 1960s as a means to compute very accurate solutions to all but the most ill-conditioned linear systems. However, two obstacles have until now prevented its adoption in standard subroutine libraries like LAPACK: (1) There was no standard way to access the higher precision arithmetic needed to compute residuals, and (2) it was unclear how to compute a reliable error bound for the computed solution. The completion of the new BLAS Technical Forum Standard has essentially removed the first obstacle. To overcome the second obstacle, we show how the application of iterative refinement can be used to compute an error bound in any norm at small cost and use this to compute both an error bound in the usual infinity norm, and a componentwise relative error bound.We report extensive test results on over 6.2 million matrices of dimensions 5, 10, 100, and 1000. As long as a normwise (componentwise) condition number computed by the algorithm is less than 1/max{10,&nsqrt;}ϵw, the computed normwise (componentwise) error bound is at most 2 max{10, &nsqrt;} · ϵw, and indeed bounds the true error. Here, n is the matrix dimension and ϵw = 2−24 is the working precision. Residuals were computed in double precision (53 bits of precision). In other words, the algorithm always computed a tiny error at negligible extra cost for most linear systems. For worse conditioned problems (which we can detect using condition estimation), we obtained small correct error bounds in over 90% of cases.
A Beam Finite Element for Shear-Critical RC Beams

The proposed beam finite element is capable of describing the response of reinforced concrete members under the interaction of axial force, shear, and bending moment. The element is based on a mixed formulation and does not exhibit the shear locking problems of displacement-based elements. The material model of the Modified Compression Field Theory by Vecchio and Collins (1986) was used to describe the biaxial response of the concrete at monitoring points across several monitoring sections along the element axis. With this model the proposed beam element is able to capture well the overall monotonic response of shear critical beams, while equally satisfactory agreement is obtained with local response measures, such as crack orientations. In spite of this promising agreement with experimental results the numerical performance of the material model was rather slow for the lack of a consistent tangent stiffness matrix. This fact coupled with the material model's inability to represent cyclic loading point out the need for a numerically consistent, robust and efficient constitutive model.