bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi-Scale Modeling of Fracture Properties for Nano-Particle Reinforced Polymers Using Atomistic J-Integral
Authors: Roy Samit , Akepati Avinash
Published: June 2016

The nano-scale interaction between polymer molecules and nanoparticle is a key factor in determining the macro-scale strength of the composite. In recent years numerous efforts have been directed towards modeling nanocomposites in order to better understand the reasons behind the enhancement of mechanical properties, even by the slight addition (a few weight percent) of nano-materials. In order to better understand the local influence of nano-particle on the mechanical properties of the composite, it is required to perform nano-scale analysis. In this context, modeling of fracture and damage in nano-graphene reinforced EPON 862 has been discussed in the current paper. Regarding fracture in polymers, the critical value of the J-integral (JI), where the subscript I denotes the fracture mode (I=1, 2, 3), at crack initiation could be used as a suitable metric for estimating the crack driving force as well as fracture toughness of the material as the crack begins to initiate. However, for the conventional macroscale definition of the J-integral to be valid at the nanoscale, in terms of the continuum stress and displacement fields and their spatial derivatives — requires the construction of local continuum fields from discrete atomistic data, and using these data in the conventional contour integral expression for atomistic J-integral. One such methodology is proposed by Hardy that allows for the local averaging necessary to obtain the definition of free energy, deformation gradient, and Piola-Kirchoff stress as fields (and divergence of fields) and not just as total system averages. Further, the atomistic J-integral takes into account the effect of reduction in J from continuum estimates due to the fact that the free energy available for crack propagation is less than the internal energy at sufficiently high temperatures when entropic contributions become significant. In this paper, the proposed methodology is used to compute J-integral using atomistic data obtained from LAMMPS (Large-scale Atomic/Molecular Massively Parallel Simulator). As a case study, the feasibility of computing the dynamic atomistic J-integral over the MD domain is evaluated for a graphene nano-platelet with a central crack using OPLS (Optimized Potentials for Liquid Simulations) potential. For model verification, the values of atomistic J-integral are compared with results from linear elastic fracture mechanics (LEFM) for isothermal crack initiation at 0 K and 300 K. Computational results related to the path-independence of the atomistic J-Integral are also presented. Further, a novel approach that circumvents the complexities of direct computation of entropic contributions is also discussed. Preliminary results obtained from the bond-order based ReaxFF potential for 0.1 K and 300 K are presented, and show good agreement with the predictions.
The Application of a Fuzzy Approach to the Analysis of OSH Practitioners Level of Risk Acceptance
Authors: Rodrigues Matilde A. , Leão Celina P. , Nunes Eusébio , Sousa Sérgio , Arezes Pedro
Published: June 2016

Organizations need constantly to take decisions about risk. In this process, Occupational Safety & Health (OSH) practitioners’ judgments have a great importance. If on one hand they have the technical knowledge about risk, on the other hand the decisions can be dependent on their level of risk acceptance. In view of this, this paper analyzes the views of the OSH practitioners about the level of risk acceptance, using the Fuzzy logic approach. A questionnaire to the analysis of the reported level of risk acceptance was developed and applied. The questionnaire included 79 risk scenarios, each accounted for the frequency of an accident with more lost workdays than a given magnitude. Through the two-step cluster analysis three groups of OSH practitioners were identified: Unacceptable, Tolerable and Realistic groups. A further analysis of the realistic group judgments about risk was performed, using the Fuzzy logic approach. The fuzzy sets of inputs and output variables were determined and the relationship between the variables was mapped through fuzzy rules. After that, the Min–Max fuzzy inference method was used. The obtained results show that the risk level is acceptable when input variables are at the lowest value and unacceptable when the risk level is high. Furthermore, the results obtained allow to better understand the uncertainty related with the OSH practitioners judgments being an important step to better understand the modeling of judgments about risk acceptance level allowing to know the different risk acceptance levels for the different accident scenarios.
Detection of Sliding Wheels and Hot Bearings Using Wayside Thermal Cameras
Authors: Deilamsalehy Hanieh , Havens Timothy C. , Lautala Pasi
Published: June 2016

Train car wheels are subjected to different types of damages due to their interactions with the brake shoes and track. If not detected early, these defects can worsen, possibly causing damage to the bogie and rail. In the worst-case scenario, this rail damage can possibly lead to later derailments, a serious concern for the rail industry. Therefore, automatic inspection and detection of wheel defects are high priority research areas. An automatic detection system not only can prevent train and rail damage, but also can reduce operating costs as an alternative for tedious and expensive manned inspection. The main contribution of this paper is to develop a computer vision method for automatically detecting the defects of rail car wheels using a wayside thermal camera. We concentrate on identification of flat-spotted/sliding wheels, which is an important issue for both wheel and suspension hardware and also rail and track structure. Flat spots occur when a wheel locks up and slides while the vehicle is still moving. As a consequence, this process heats up local areas on the metal wheel, which can be observed and potentially detected in thermal imagery. Excessive heat buildup at the flat spot will eventually lead to additional wheel and possibly rail damage, reducing the life of other train wheels and suspension components, such as bearings. Furthermore, as a byproduct of our algorithm, we propose a method for detecting hot bearings. A major part of our proposed hot bearing detection algorithm is common with our sliding wheel detection algorithm. In this paper, we first propose an automatic detection and segmentation method that identifies the wheel and bearing portion of the image. We then develop a computer vision method, using Histogram of Oriented Gradients to extract features of these regions. These feature descriptors are input to a Support Vector Machine classifier, a fast classifier with a good detection rate, which can detect abnormalities in the wheel. We demonstrate our methods on several real data sets taken on a Union Pacific rail line, identifying sliding wheels and hot bearings in these images.
Optimized Rail Grinding Through Dynamic Positioning and Powering of Grinding Motors
Authors: Hartsough Christopher M. , Palese Joseph W. , Schmitzer Gabriel , Espindola Jean Carlos , Viana Thiago Gomes
Published: June 2016

Rail grinding has become a widely accepted practice in the railroad industry to not only remove surface defects but to also shape the head of the rail to achieve a specific wheel/rail contact interface. Optimal wheel/rail contact is paramount for a variety of reasons including (but not limited to): reduced rail wear and fatigue defects with associated increased rail life, improved steering, and reduced wheel/rail noise. Historically, the process of profile grinding has been performed through the selection of a grinding pattern from a predefined library of preset motor angles and power settings, as well as grinder traveling speed. By applying calibrated metal removal equations created to estimate the metal removal of a single grinding stone on a specific grinding vehicle and a measured shape of the rail, it is possible to iteratively create a grinding pattern and estimate the post-grind rail shape in both real-time and offline. These dynamically created grinding patterns position and power grinding motors to remove metal only where it needs to be removed to achieve the desired rail shape (template). Over grinding and extraneous grinding is minimized using this grind optimization technique.

The concept of dynamic rail grinding pattern generation was applied to optimize grinding for the VLI railroad in Brazil. Based on a survey of both wheel profiles and rail profiles throughout the VLI network (in which digital coordinates of the transverse cross-sections were recorded using handheld profile measurement devices), new rail grinding templates (desired rail shape dependent upon rail curvature and elevation) were developed to control the wheel/rail interface. These new rail grinding templates were aligned to measured rail profiles categorized by curvature and high/low rail types to create representative average metal removal curves. The resulting metal removal curves were then used as inputs to the dynamic grinding pattern generation functions to create custom grinding patterns specifically calibrated to the grinder in operation on VLI.

Results showed that applying dynamic grinding pattern generation resulted in increased productivity of the grinder (faster speeds and less passes) with corresponding improvement of the post-grind rail shape, i.e., increased quality of the final rail shape.

This paper will discuss the background theory behind dynamic pattern generation and how it can be applied to normal grinding operations. Additionally, an application of this process will be presented which utilized dynamic pattern generation to create targeted corrective grinding patterns for the VLI railroad.
Modeling of Diffraction Coupling in Radio Propagation Inside Tunnel Environments
Authors: Aziminejad Arash , Lee Andrew W. , Epelbaum Gabriel
Published: June 2016

The overall performance of a Communication-Based Train Control (CBTC) system largely depends on the performance of its Data Communication Subsystem (DCS). The DCS network in almost all CBTC commercial system products marketed in the last decade utilizes radio communications in the open ISM bands (2.4 GHz or 5.8 GHz) to establish the bi-directional data link between the central/wayside and onboard segments. To ensure a stable and sound radio communication, a key question is the number of the wayside Access Points (APs) and locations of their antennas. Radio propagation modeling aims to provide an optimal and reasonably reliable solution to the cited question. The diffraction impact of sharp corners and edges in tunnels on the radio propagation process, however, has not been accounted for in majority of models. The purpose of the present research is to incorporate the effect of diffraction coupling due to sharp edges in tunnel sections which include geometrical discontinuities such as cross-junctions and L-bends through ray-mode conversion. The proposed modeling approach offers sufficient versatility to assimilate a variety of discontinuous geometries involving sharp edges in a tunnel environment. Numerical and empirical results suggest that the model provides an accurate tool for analyzing diffraction effects of tunnel discontinuities with sharp edges on the process of radio propagation.
Suitability and Variability of Non-Destructive Testing Methods for Concrete Railroad Tie Inspection
Authors: Shafiei Aref , Riding Kyle A. , Peterman Robert J. , Christensen Chris , Beck B. Terry , Robertson Aaron A. , Wu Chih-Hang John
Published: June 2016

Concrete railroad ties have been used in increasing numbers in the U.S., particularly in high-speed rail, heavy-haul freight lines, and new track construction because of their reduced deflections, durability, and competitive cost. In-track assessment of concrete railroad ties can be a challenge, however because many exterior tie surfaces are covered by tie pads and rail or ballast. This damage may include concrete section wear from abrasion, cracking, or crumbling, or other types of defects. Damage internal to the concrete can also not be seen visually. The time and cost needed to inspect these tie surfaces means that it is not routinely performed. Non-destructive testing offers promise as a way to assess concrete tie integrity without having to remove ballast, however more information is needed to know how well non-destructive techniques work in detecting damage. Two of the most promising techniques for investigating the integrity of concrete non-destructively are ultrasonic pulse velocity and impact-echo. Ultrasonic pulse velocity (UPV) and Impact-echo (IE) were applied to investigate the uniformity of concrete railroad tie and its cavities, cracks and defects for concrete ties taken from track after service. This paper evaluated the variability of the test results in UPV and IE testing condition in which two concrete railroad ties with same manufacture and load history condition were tested in both methods. Two additional concrete ties with the same manufacture and load history as each other with visible longitudinal cracks were also examined to see how the damage affected the variability measured. For this purpose, wave pulse for every full length tie from full top, half top, longitude and two sides were measured using ultrasonic pulse (ASTM C597). Also, thickness of concrete ties on both sides, including rail seat location and the middle were assessed by standard tests method for measuring the p-wave speed and the thickness of concrete using the impact-echo method (ASTM C1383). Advice is given on how to interpret ultrasonic pulse velocity and impact-echo measurements and given the variability of the test method how to flag ties for potential deterioration given that most ties in service will not have initial measurements taken before damage for comparison.
Effect of Temperature on Hardening and Residual Stress Development During Wheel/Rail Rolling Contact
Authors: Dedmon Steven , Kato Takanori , Pilch James
Published: June 2016

Brake heating of Railroad Wheels has been known to accelerate shelling, soften the wheel tread and contribute to stress reversal which is a requisite for generating thermal cracks. The effect brake heating has on shakedown has been investigated to a lesser extent, yet even here brake heating can be very important. This research combines field investigations and laboratory work in an attempt to quantify the thermal effects on wheel performance, especially as it relates to sub-surface shelling, microstructural changes and hardening mechanisms. Cyclic tensile tests were conducted at three temperatures to show the relationship between deformation at elevated temperatures and hardening response. Ductility measurements from both monotonic and cyclic tests were used to estimate residual stresses.
Dynamic Load Augment From Steam Locomotives
Authors: Fairbanks Gary , Weisinger Harold , Zuiderveen Steven , Prabhakaran Anand , Buel Tanner
Published: June 2016

Railroad bridges experience dynamic wheel load augment from rolling stock that cross the bridges, due to nominal bridge and suspension dynamics, as well as anomalies such as wheel flats. The level of dynamic augment is particularly high for steam locomotives due to the hammer blow effect associated with the driven wheels. Tests conducted in the early-mid 20th century had quantified some of these effects, and the resulting findings have been part of the impact formulae presented in the AREMA Railway Engineering Manual.

However, there was concern that the impact associated with some of the non-cross counter-balanced, lighter, older locomotives, could be higher than specified by AREMA formulae. This paper describes the methodology and results from a series of tests that evaluated the levels of dynamic augment experienced by railroad track and an exemplar bridge under a set of narrow gauge steam locomotives, and compares the measurements to the design values specified in the AREMA Manual. Vertical and lateral loads on railroad track, and strain levels on multiple critical bridge members were measured under three different classes of light, narrow gauge steam locomotives, over a range of operating speeds and conditions. The tests were conducted on a 120 ft span, through truss bridge, and adjacent track on a tourist railroad.

Dynamic augment values measured during the tests were generally lower than the values expected from AREMA formulae. Similarly, the peak lateral loads measured appear to be nominal and lower than the AREMA prescribed values. However, it should be kept in mind that these results are from tests conducted with three relatively light, narrow gauge locomotives, on specific bridge and track, whereas, the AREMA formulae are intended to cover a wider range of conditions. These tests tend to show that the legacy standards are conservative and are applicable to calculating regulatory required bridge loads where steam locomotives are concerned.
Technical Note: Gray tracking in medical color displays—A report of Task Group 196
Authors: Badano Aldo , Wang Joel , Boynton Paul , Le Callet Patrick , Cheng Wei‐Chung , Deroo Danny , Flynn Michael J. , Matsui Takashi , Penczek John , Revie Craig , Samei Ehsan , Steven Peter M. , Swiderski Stan , Van Hoey Gert , Yamaguchi Matsuhiro , Hasegawa Mikio , Nagy Balázs Vince
Published: June 2016

Purpose:

The authors discuss measurement methods and instrumentation useful for the characterization of the gray tracking performance of medical color monitors for diagnostic applications. The authors define gray tracking as the variability in the chromaticity of the gray levels in a color monitor.

Methods:

The authors present data regarding the capability of color measurement instruments with respect to their abilities to measure a target white point corresponding to the CIE Standard Illuminant D65 at different luminance values within the grayscale palette of a medical display. The authors then discuss evidence of significant differences in performance among color measurement instruments currently available for medical physicists to perform calibrations and image quality checks for the consistent representation of color in medical displays. In addition, the authors introduce two metrics for quantifying grayscale chromaticity consistency of gray tracking.

Results:

The authors’ findings show that there is an order of magnitude difference in the accuracy of field and reference instruments. The gray tracking metrics quantify how close the grayscale chromaticity is to the chromaticity of the full white point (equal amounts of red, green, and blue at maximum level) or to consecutive levels (equal values for red, green, and blue), with a lower value representing an improved grayscale tracking performance. An illustrative example of how to calculate and report the gray tracking performance according to the Task Group definitions is provided.

Conclusions:

The authors’ proposed methodology for characterizing the grayscale degradation in chromaticity for color monitors that can be used to establish standards and procedures aiding in the quality control testing of color displays and color measurement instrumentation.
Accuracy of a dose‐area product compared to an absorbed dose to water at a point in a 2 cm diameter field
Authors: Dufreneix S. , Ostrowsky A. , Rapp B. , Daures J. , Bordy J. M.
Published: June 2016

Purpose:

Graphite calorimeters with a core diameter larger than the beam can be used to establish dosimetric references in small fields. The dose‐area product (DAP) measured can theoretically be linked to an absorbed dose at a point by the determination of a profile correction. This study aims at comparing the DAP‐based protocol to the usual absorbed dose at a point protocol in a 2 cm diameter field for which both references exist.

Methods:

Two calorimeters were used, respectively, with a sensitive volume of 0.6 cm (for the absorbed dose at a point measurement) and 3 cm diameter (for the DAP measurement). Profile correction was calculated from a 2D dose mapping using three detectors: a PinPoint chamber, a synthetic diamond, and EBT3 films. A specific protocol to read EBT3 films was implemented and the dose‐rate and energy dependences were studied to assure a precise measurement, especially in the penumbra and out‐of‐field regions.

Results:

EBT3 films were found independent on dose rates over the range studied but showed a strong under‐response (18%) at low energies. Depending on the dosimeter used for calculating the profile correction, a deviation of 0.8% (PinPoint chamber), 0.9% (diamond), or 1.9% (EBT3 films) was observed between the calibration coefficient derived from DAP measurements and the one directly established in terms of absorbed dose to water at a point.

Conclusions:

The DAP method can currently be linked to the classical dosimetric reference system based in an absorbed dose at a point only with a confidence interval of 95% (k = 2). None of the detectors studied can be used to determine an absorbed dose to water at a point from a DAP measurement with an uncertainty smaller than 1.2%.
Measuring Physical Activity in Older Adults Using MotionWatch 8 Actigraphy: How Many Days are Needed?
Authors: Falck Ryan S. , Landry Glenn J. , Brazendale Keith , Liu-Ambrose Teresa
Published: June 2016

Evidence suggests sleep and physical activity (PA) are associated with each other and dementia risk. Thus, identifying reliable methods to quantify sleep and PA concurrently in older adults is important. The MotionWatch 8© (MW8) wrist-worn actigraph provides reliable estimates of sleep quality via 14 days of measurement; however, the number of days needed to monitor PA by MW8 for reliable estimates is unknown. Thus, we investigated the number of days of MW8 wear required to assess PA in older adults. Ninety-five adults aged > 55 years wore MW8 for ≥ 14 days. Spearman-Brown analyses indicated the number of monitoring days needed for an ICC = 0.95 was 6–7 days for sedentary activity, 9–10 days for light activity, and 7–8 days for moderate-to-vigorous PA. These results indicate 14 days of MW8 monitoring provides reliable estimates for both sleep and PA. Thus, MW8 is ideal for future investigations requiring concurrent measures of both sleep quality and PA.
The Cameo Effect of Host Country and the Transitory Mega-Event: Patterns of Effect on Sponsorship Evaluation for Sport Tourists and Residents
Authors: Nadeau John , O’Reilly Norm , Cakmak Erdinc , Heslop Louise , Verwey Sonja
Published: June 2016

In this paper, the authors address a literature gap with regard to sponsorship outcomes of mega-events and their host countries. This paper is about research that investigates the interrelatedness of three important images—host country, mega-event, and sponsor images—from the perspective of a cameo appearance building on the sponsorship and brand placement literature. It is based on the premise that the host city makes a cameo appearance during a mega-event for sport tourists while the event itself makes a cameo appearance for residents of the host country. The results indicate that mega-events can have a transitory influence, and that cameo effects exist, but that the patterns of relationships are different for sport tourists and residents.
Draft Genome Sequence of the Basidiomycetous Fungus
Flammulina velutipes
TR19
Authors: Kurata Atsushi , Fukuta Yasuhisa , Mori Miho , Kishimoto Noriaki , Shirasaka Norifumi
Published: June 2016

Here, we report the draft genome sequence of
Flammulina velutipes
TR19, which was newly isolated from commercial strains in Japan. The genes related to fruiting body formation in the basidiomycete were identified by whole-genome analysis.
Complete Genome Sequence of a Clinical Isolate of Enterobacter asburiae
Authors: Liu Feng , Yang Jian , Xiao Yan , Li Li , Yang Fan , Jin Qi
Published: June 2016

We report here the complete genome sequence of
Enterobacter asburiae
strain ENIPBJ-CG1, isolated from a bone marrow transplant patient. The size of the genome sequence is approximately 4.65 Mb, with a G+C content of 55.76%, and it is predicted to contain 4,790 protein-coding genes.
Draft Genome Sequence of Carbaryl-Degrading Soil Isolate
Pseudomonas
sp. Strain C5pp
Authors: Trivedi Vikas D. , Jangir Pramod Kumar , Sharma Rakesh , Phale Prashant S.
Published: June 2016

We report the draft genome sequence of carbaryl-degrading
Pseudomonas
sp. strain C5pp. Genes encoding salicylate and gentisate metabolism, large amounts of oxygenase, nitrogen metabolism, and heavy metal tolerance were identified. The sequence will provide further insight into the biochemical and evolutionary aspects of carbaryl degradation.
Chromosome and Plasmids of the Tick-Borne Relapsing Fever Agent Borrelia hermsii
Authors: Barbour Alan G.
Published: June 2016

The zoonotic pathogen
Borrelia hermsii
bears its multiple paralogous genes for variable antigens on several linear plasmids. Application of combined long-read and short-read next-generation sequencing provided complete sequences for antigen-encoding plasmids as well as other linear and circular plasmids and the linear chromosome of the genome.
Trajectories of maternal gestational weight gain and child cognition assessed at 5 years of age in a prospective cohort study
Authors: Hinkle Stefanie N , Albert Paul S , Sjaarda Lindsey A , Grewal Jagteshwar , Grantz Katherine L
Published: June 2016

Background

There has been concern that low gestational weight gain may cause poor fetal neurodevelopment.

Methods

The association between maternal weight gain and child IQ was examined using serial antenatal weight measurements (median 12) from a prospective cohort of non-obese Scandinavian women (1986–1988). Linear mixed models with piecewise regression were used to estimate participants’ (n=552) trimester-specific average rate of weight gain. Linear regression was used to assess the association between weight gain and children's (n=344) full-scale, performance and verbal IQ measured at age 5 using the Wechsler Preschool and Primary Scales of Intelligence-Revised.

Results

Children born to mothers who gained below versus within the 2nd trimester 2009 recommendations tended to have lower IQ scores (Full-scale: 106.6 (SD 15.1) vs 110.2 (15.2), p=0.04; verbal: 102.5 (14.3) vs 105.0 (14.9), p=0.10; performance: 109.5 (15.4) vs 113.4 (14.5), p=0.03). After adjustment there were no differences in child IQ by weight gain adequacy (full-scale: βbelow=−1.1 (95% CI −5.1 to 2.9), βabove=1.5 (−3.8 to 6.8); verbal: βbelow=−0.2 (−3.1 to 2.6), βabove=1.8 (−3.6 to 7.3); performance βbelow=−1.2 (−4.6 to 2.2), βabove=1.0 (−4.6 to 6.7)). No differences were observed based on 3rd trimester adequacy. No differences were observed in IQ scores by quintile of weight gain for any trimester, particularly after adjustment for maternal IQ.

Conclusions

Our findings are reassuring that among normal weight women, pregnancy weight gain is not associated with child cognitive development. Further investigation should be conducted in contemporary cohorts that also include obese mothers, who are at the greatest risk for low weight gain.
On being an expert witness in sexual and reproductive health
Authors: Rowlands Sam
Published: June 2016

A new generation of expert witnesses in sexual and reproductive health is needed, including those in nursing as well as medical roles. Being an expert witness is a significant commitment alongside clinical work. Nevertheless, the work is stimulating and rewarding. Training is essential before starting medicolegal work. In particular expert witnesses need to be able to apply appropriate legal tests to the evidence, to deal with the range of expert opinion on a matter, and explain clearly what constitutes an appropriate standard of care for a clinician in their discipline and specialty. Expert witnesses must be aware of pitfalls such as being sued for substandard work and being reported to their professional regulator for straying outside their area of expertise. Expert witnesses must be truly independent and ideally their reports should be the same whoever they receive their instructions from. In addition to report writing, expert witnesses are required to comment on court documents, participate in conferences with a barrister and hold formal discussions with an opposing expert witness. Expert witnesses need to be administratively efficient and responsive. Although appearance in court is not that common, this is an essential part of the role. Apart from litigation in the civil courts, other types of case may present themselves including patent cases, work in the Court of Protection and health professionals' Fitness to Practise hearings.
Fungi associated with hibernating bats in New Brunswick caves: the genus Leuconeurospora
Authors: Malloch David , Sigler Lynne , Hambleton Sarah , Vanderwolf Karen J. , Gibas Connie Fe C. , McAlpine Donald F.
Published: June 2016

Two species of Leuconeurospora, Leuconeurospora capsici (J.F.H. Beyma) Malloch, Sigler & Hambleton and Leuconeurospora polypaeciloides Malloch, Sigler & Hambleton (Ascomycota: Pseudeurotiaceae), are reported from the fur and skin of hibernating bats and from other substrata in caves in New Brunswick, Canada. Separate analyses using ITS, RPB1, and RPB2 DNA sequence data are in agreement and show these two species and the type species, Leuconeurospora pulcherrima (G. Winter) Malloch & Cain, form discrete clades within a distinct Leuconeurospora clade. The three species are distinguishable morphologically by their anamorphs, having dark conidia in L. capsici, hyaline conidia in L. polypaeciloides, and no conidia in L. pulcherrima. Ascomata and ascospores are produced in L. pulcherrima and in mated isolates of L. polypaeciloides, but have not been observed in L. capsici. Leuconeurospora species are psychrotolerant, with faster growth and heavier conidial development at 7 °C than at 22 °C. Of 151 bats sampled from 10 caves, 51 yielded isolates of L. polypaeciloides and 15 yielded L. capsici. The results were not uniform: neither species was isolated from bats in three caves, while three caves yielded isolates of both species and two yielded L. polypaeciloides only. These species were also isolated from cave walls and arthropods in the cave.
A forecasting methodology for predicting frazil ice flooding along urban streams using hydro-meteorological data
Authors: Gholamreza-Kashi Soheil
Published: June 2016

Flooding due to ice jams in urban streams, resulting in damages to residential and commercial property, is a common problem in northern regions. Ice-related flooding events have occurred on several occasions along the lower reach of Spencer Creek within Hamilton, Ontario. This study is completed to develop a methodology using the available flow and temperature data to predict the potential for occurrence of flooding due to frazil ice accumulation. Meteorological and hydrometric data as well as historical information were collected and analyzed. Degree days of freezing and mass flow curves for previous events were investigated. Two indices for temperature and flow were defined. A methodology was developed to predict the potential of flooding using the defined curves and indices based on current temperature and flow data. This methodology is currently being used to predict potential occurrence of frazil ice flooding along Spencer Creek and may be adapted for use in other watercourses in Canada and elsewhere.
Maximum intrinsic rate of population increase in sharks, rays, and chimaeras: the importance of survival to maturity
Authors: Pardo Sebastián A. , Kindsvater Holly K. , Reynolds John D. , Dulvy Nicholas K.
Published: June 2016

The maximum intrinsic rate of population increase (rmax) is a commonly estimated demographic parameter used in assessments of extinction risk. In teleosts, rmax can be calculated using an estimate of spawners per spawner, but for chondrichthyans, most studies have used annual reproductive output (b) instead. This is problematic as it effectively assumes all juveniles survive to maturity. Here, we propose an updated rmax equation that uses a simple mortality estimator that also accounts for survival to maturity: the reciprocal of average life-span. For 94 chondrichthyans, we now estimate that rmax values are on average 10% lower than previously published. Our updated rmax estimates are lower than previously published for species that mature later relative to maximum age and those with high annual fecundity. The most extreme discrepancies in rmax values occur in species with low age at maturity and low annual reproductive output. Our results indicate that chondrichthyans that mature relatively later in life, and to a lesser extent those that are highly fecund, are less resilient to fishing than previously thought.
CO2 laser enhances the chilling tolerance of wheat seedlings by stimulating NO synthesis
Authors: Chen Yi-ping , Liu Qiang , Chen Dong
Published: June 2016

To investigate the mechanism by which laser irradiation enhances the chilling tolerance of wheat seedlings, seeds were exposed to different treatments, and biochemical parameters were measured. Compared with the control group, chilling stress (CS) led to an increase in the concentrations of malondialdehyde (MDA) and H2O2, and decreases in the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR), catalase (CAT), peroxidase (POD), and nitric oxide synthase (NOS), and the concentrations of nitric oxide (NO) and protein. Treatment with 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO), sodium tungstate (ST), and NG-nitro-L-arginine methyl ester (L-NAME) followed by CS resulted in further increases in the concentrations of MDA and H2O2 and further decreases in the other parameters. However, treatment with PTIO, ST, and L-NAME followed by laser irradiation had the opposite effects on these parameters. When the seeds were treated with PTIO, ST, and L-NAME followed by laser and CS, the concentrations of MDA and H2O2 were significantly lower and the other parameters were higher than in the PTIO, ST, and L-NAME plus CS groups. These results suggest that CO2 laser irradiation enhances the chilling tolerance of wheat seedlings by stimulating endogenous NO synthesis.
On Low Rank Approximation of Linear Operators in p-Norms and Some Algorithms
Authors: Liu Yang
Published: June 2016

In this paper, we study the optimal or best approximation of any linear operator by low rank linear operators, especially, any linear operator on the [Formula: see text]-space, [Formula: see text], under [Formula: see text] norm, or in Minkowski distance. Considering generalized singular values and using techniques from differential geometry, we extend the classical Schmidt–Mirsky theorem in the direction of the [Formula: see text]-norm of linear operators for some [Formula: see text] values. Also, we develop and provide algorithms for finding the solution to the low rank approximation problems in some nontrivial scenarios. The results can be applied to, in particular, matrix completion and sparse matrix recovery.
Vassiliev invariants from symmetric spaces
Authors: Biswas Indranil , Gammelgaard Niels Leth
Published: June 2016

We construct a natural framed weight system on chord diagrams from the curvature tensor of any pseudo-Riemannian symmetric space. These weight systems are of Lie algebra type and realized by the action of the holonomy Lie algebra on a tangent space. Among the Lie algebra weight systems, they are exactly characterized by having the symmetries of the Riemann curvature tensor.
Modal Analysis of a Vertically Tapered Frame
Authors: Chandravanshi M. L. , Mukhopadhyay A. K.
Published: June 2016

The paper delineates the procedure to assess probable failure sections through the dynamic conditions of a vertically tapered frame using the experimental modal analysis (EMA), which is validated through the finite element analysis (FEA). The modal parameters are experimentally determined by the frequency response functions (FRFs) using the accelerometer, force transducer, electro-dynamic shaker, dynamic signal analyzer (DSA) and post processed by the ME’Scope software. The ANSYS Workbench 14 was used for finding the modal parameters through the FEA. The FEA model was also tested by convergence study. The boundary conditions of the vertically tapered frame in the FEA is kept similar to the EMA. The values obtained by the two methods have been compared for their proximity.
Harmonic measures in embedded foliated manifolds
Authors: Catuogno Pedro J. , Ledesma Diego S. , Ruffino Paulo R.
Published: June 2016

We study harmonic and totally invariant measures in a foliated compact Riemannian manifold. We construct explicitly a Stratonovich differential equation for the foliated Brownian motion. We present a characterization of totally invariant measures in terms of the flow of diffeomorphisms associated to this equation. We prove an ergodic formula for the sum of the Lyapunov exponents in terms of the geometry of the leaves.
Persistence property for some classes of monomial ideals of a polynomial ring
Authors: Nasernejad Mehrdad
Published: June 2016

Let [Formula: see text] be a field and [Formula: see text] be a polynomial ring in the variables [Formula: see text]. In this paper, we introduce two classes of monomial ideals of [Formula: see text], which have the following properties:

(i) The (strong) persistence property of associated prime ideals. (ii) There exists a strongly superficial element. (iii) Ratliff–Rush closed.

Next, we characterize these monomial ideals. In the sequel, we give some combinatorial aspects. We conclude this paper with constructing new monomial ideals, which have the persistence property.
Effect of alkaline earth metal at the single wall CNT mouth on the electronic structure and second hyperpolarizability
Authors: Hatua Kaushik , Nandi Prasanta K.
Published: June 2016

In the present work, electronic structure and second hyperpolarizability of a number of alkaline earth metals (M [Formula: see text] Be, Mg and Ca) complexes with carbon nanotube (CNT) has been studied by using different DFT functional. The complexes have sufficient thermal stability. Significant amount of charge transfer from metal to CNT results in stronger ground state polarization. The second hyperpolarizability obtained at different DFT functional (BHHLYP, CAM-B3LYP, B2PLYP, [Formula: see text]B97XD) showed a consistent trend. The magnitude of second hyperpolarizability of M@CNT[3,0] complexes enhances rather appreciably when a second metal atom is introduced into other mouth position. The longitudinal component of second hyperpolarizability of M@CNT[3,0]@M complexes increases with increasing size of metal atom. The magnitude of second hyperpolarizability of Ca@CNT[3,0]@Ca complex is comparable with Fe([Formula: see text]-C[Formula: see text]B[Formula: see text]. However, widening/lengthening of CNT markedly reduces the cubic responses. The two state model can qualitatively explain the variation of second hyperpolarizability.
A possible symplectic framework for Radon-type transforms
Authors: Cahen Michel , Grouy Thibaut , Gutt Simone
Published: June 2016

Our project is to define Radon-type transforms in symplectic geometry. The chosen framework consists of symplectic symmetric spaces whose canonical connection is of Ricci-type. They can be considered as symplectic analogues of the spaces of constant holomorphic curvature in Kählerian Geometry. They are characterized amongst a class of symplectic manifolds by the existence of many totally geodesic symplectic submanifolds. We present a particular class of Radon type transforms, associating to a smooth compactly supported function on a homogeneous manifold [Formula: see text], a function on a homogeneous space [Formula: see text] of totally geodesic submanifolds of [Formula: see text], and vice versa. We describe some spaces [Formula: see text] and [Formula: see text] in such Radon-type duality with [Formula: see text] a model of symplectic symmetric space with Ricci-type canonical connection and [Formula: see text] an orbit of totally geodesic symplectic submanifolds.
Evaluating the Effect of Buckling-Restrained Brace Model on Seismic Structural Responses
Authors: Feng Yulong , Wu Jing , Wang Chunlin , Meng Shaoping
Published: June 2016

Numerical simulation is an important measure to study the seismic performance of buckling-restrained braced frames (BRBFs). Practically, some simplified models, such as the elastic–plastic with kinematic hardening model and the elastic perfectly-plastic model, are used to simulate the behavior of buckling-restrained brace (BRBs). To provide structural engineers the reference of errors when simplified models are used, this paper comparatively evaluates the effect of the BRB model on seismic structural responses using the OpenSees software. A comparison is made on six-storey and 16-storey BRBFs with rigid beam-to-column connections; these are designed according to Chinese seismic design code. Moreover, the effects of the post-yielding stiffness ratio of frame [Formula: see text] and the stiffness ratio of BRB to frame [Formula: see text] on the errors are specifically investigated through a parametric study of both BRBFs. The results show that the seismic response average errors of the simplified models are mostly less than 5%, which satisfies the engineering requirements.
Certain chromatic sums of some cycle-related graph classes
Authors: Sudev N. K. , Chithra K. P. , Kok Johan
Published: June 2016

Let [Formula: see text] be a certain type of proper [Formula: see text]-coloring of a given graph [Formula: see text] and [Formula: see text] denote the number of times a particular color [Formula: see text] is assigned to the vertices of [Formula: see text]. Then, the coloring sum of a given graph [Formula: see text] with respect to the coloring [Formula: see text], denoted by [Formula: see text] is defined to be [Formula: see text]. The coloring sums such as [Formula: see text]-chromatic sum, [Formula: see text]-chromatic sum, [Formula: see text]-chromatic sum, [Formula: see text]-chromatic sum, etc. are some of these types of coloring sums that have been studied recently. Motivated by these studies on certain chromatic sums of graphs, in this paper, we study certain chromatic sums for some standard cycle-related graphs.
Trust-Based Decision Making in a Self-Adaptive Agent Organization
Authors: Ahmadi Kamilia , Allan Vicki H.
Published: June 2016

Interaction between agents is one of the key factors in multiagent societies. Using interaction, agents communicate with each other and cooperatively execute complex tasks that are beyond the capability of a single agent. Cooperatively executing tasks may endanger the success of an agent if it attempts to cooperate with peers that are not proficient or reliable. Therefore, agents need to have an evaluation mechanism to select peers for cooperation. Trust is one of the measures commonly used to evaluate the effectiveness of agents in cooperative societies. Since all interactions are subject to uncertainty, the risk behavior of agents as a contextual factor needs to be taken into account in decision making. In this research, we propose the concept of adaptive risk and agent strategy along with an algorithm that helps agents make decisions in an self-adaptive society utilizing an agent’s own experience and recommendation-based trust. Trust-based decision making increases the profit of the system along with lower task failure in comparison to a no-trust model in which agents do not utilize evaluation mechanisms for choosing their cooperation peers.
Probabilistic Models for Contextual Agreement in Preferences
Authors: Do Loc , Lauw Hady W.
Published: June 2016

The long-tail theory for consumer demand implies the need for more accurate personalization technologies to target items to the users who most desire them. A key tenet of personalization is the capacity to model user preferences. Most of the previous work on recommendation and personalization has focused primarily on individual preferences. While some focus on shared preferences between pairs of users, they assume that the same similarity value applies to all items. Here we investigate the notion of “context,” hypothesizing that while two users may agree on their preferences on some items, they may also disagree on other items. To model this, we design probabilistic models for the generation of rating differences between pairs of users across different items. Since this model also involves the estimation of rating differences on unseen items for the purpose of prediction, we further conduct a systematic analysis of matrix factorization and tensor factorization methods in this estimation, and propose a factorization model with a novel objective function of minimizing error in rating differences. Experiments on several real-life rating datasets show that our proposed model consistently yields context-specific similarity values that perform better on a prediction task than models relying on shared preferences.
Artificial Immunology for Collective Adaptive Systems Design and Implementation
Authors: Capodieci Nicola , Hart Emma , Cabri Giacomo
Published: June 2016

Distributed autonomous systems consisting of large numbers of components with no central control point need to be able to dynamically adapt their control mechanisms to deal with an unpredictable and changing environment. Existing frameworks for engineering self-adaptive systems fail to account for the need to incorporate self-expression—that is, the capability of a system to dynamically adapt its coordination pattern during runtime. Although the benefits of incorporating self-expression are well known, currently there is no principled means of enabling this during system design. We propose a conceptual framework for principled design of systems that exhibit self-expression, based on inspiration from the natural immune system. The framework is described as a set of design principles and customizable algorithms and then is instantiated in three case studies, including two from robotics and one from artificial chemistry. We show that it enables self-expression in each case, resulting in systems that are able to adapt their choice of coordination pattern during runtime to optimize functional and nonfunctional goals, as well as to discover novel patterns and architectures.
Multi-Step Learning and Adaptive Search for Learning Complex Model Transformations from Examples
Authors: Baki Islem , Sahraoui Houari
Published: June 2016

Model-driven engineering promotes models as main development artifacts. As several models may be manipulated during the software-development life cycle, model transformations ensure their consistency by automating model generation and update tasks. However, writing model transformations requires much knowledge and effort that detract from their benefits. To address this issue, Model Transformation by Example (MTBE) aims to learn transformation programs from source and target model pairs supplied as examples. In this article, we tackle the fundamental issues that prevent the existing MTBE approaches from efficiently solving the problem of learning model transformations. We show that, when considering complex transformations, the search space is too large to be explored by naive search techniques. We propose an MTBE process to learn complex model transformations by considering three common requirements: element context and state dependencies and complex value derivation. Our process relies on two strategies to reduce the size of the search space and to better explore it, namely, multi-step learning and adaptive search. We experimentally evaluate our approach on seven model transformation problems. The learned transformation programs are able to produce perfect target models in three transformation cases, whereas precision and recall values larger than 90% are recorded for the four remaining cases.