Miracle-dz/UniFAR-FTUs huggingface dataset:
Transient perturbation growth in time-dependent mixing layers

Abstract We investigate numerically the transient linear growth of three-dimensional (3D) perturbations in a homogeneous time-evolving mixing layer in order to identify which perturbations are optimal in terms of their kinetic energy gain over a finite, predetermined time interval. We model the mixing layer with an initial parallel velocity distribution $\mathbi{U}(y)= {U}_{0} \tanh (y/ d)\mathbi{e}_{x}$ with Reynolds number $Re= {U}_{0} d/ \nu = 1000$ , where $\nu $ is the kinematic viscosity of the fluid. We consider a range of time intervals on both a constant ‘frozen’ base flow and a time-dependent two-dimensional (2D) flow associated with the growth and nonlinear saturation of two wavelengths of the most-unstable eigenmode of linear theory of the initial parallel velocity distribution, which rolls up into two classical Rayleigh instabilities commonly referred to as Kelvin–Helmholtz (KH) billows, which eventually pair to form a larger vortex. For short times, the most-amplified perturbations on the frozen $\tanh $ profile are inherently 3D, and are most appropriately described as oblique wave ‘OL’ perturbations which grow through a combination of the Orr and lift-up mechanisms, while for longer times, the optimal perturbations are 2D and similar to the KH normal mode, with a slight enhancement of gain. For the time-evolving KH base flow, OL perturbations continue to dominate over sufficiently short time intervals. However, for longer time intervals which involve substantial evolution of the primary KH billows, two broad classes of inherently 3D linear optimal perturbation arise, associated at low wavenumbers with the well-known core-centred elliptical translative instability, and at higher wavenumbers with the braid-centred hyperbolic instability. The hyperbolic perturbation is relatively inefficient in exploiting the gain of the OL perturbations, and so only dominates the smaller wavenumber (ultimately) core-centred perturbations when the time evolution of the base flow or the start time of the optimization interval does not allow the OL perturbations much opportunity to grow. When the OL perturbations can grow, they initially grow in the braid, and then trigger an elliptical core-centred perturbation by a strong coupling with the primary KH billow. If the optimization time interval includes pairing of the primary billows, the secondary elliptical perturbations are strongly suppressed during the pairing event, due to the significant disruption of the primary billow cores during pairing.
Knowledge work: gender-blind or gender-biased?

Knowledge-intensive firms (KIFs) have been the subject of growing interest from researchers. However, investigations into the comparative experiences of men and women in KIFs remain sparse, and little is known about women’s participation in the processes of innovation and knowledge exchange and combination that are core features of KIFs. The article reports on the findings of a study in the UK and Ireland involving 498 male and female knowledge workers in KIFs. Despite equal levels of qualification and experience, women are more likely to be in lower status and less secure jobs. They also predominantly occupy roles featuring less variety and autonomy than men and, despite comparable levels of knowledge exchange and combination, are less likely to be in a position to translate this into the innovative work behaviours necessary for career advancement. The findings suggest that women’s experiences of and participation in knowledge processes within KIFs differ fundamentally from men’s.
RECOGNITION OF VEHICLE NUMBER PLATES AND RETRIEVAL OF VEHICLE OWNER’S REGISTRATION DETAILS

Automatic vehicle number plate recognition system is a system plays an important role in traffic controlling, security checks, toll gates and road accidents. In this paper vehicle numbers are recognized and later used for retrieval of vehicle owner details for the above said purposes. Morphological operations and edge features are used for the segmentation of vehicle number using two level decisions. An efficient algorithm is proposed and tested on large set of images and demonstrated the efficacy of the proposed approach.
Future permafrost conditions along environmental gradients in Zackenberg, Greenland

Abstract. The future development of ground temperatures in permafrost areas is determined by a number of factors varying on different spatial and temporal scales. For sound projections of impacts of permafrost thaw, scaling procedures are of paramount importance. We present numerical simulations of present and future ground temperatures at 10 m resolution for a 4 km long transect across the lower Zackenberg valley in northeast Greenland. The results are based on stepwise downscaling of future projections derived from general circulation model using observational data, snow redistribution modeling, remote sensing data and a ground thermal model. A comparison to in situ measurements of thaw depths at two CALM sites and near-surface ground temperatures at 17 sites suggests agreement within 0.10 m for the maximum thaw depth and 1 °C for annual average ground temperature. Until 2100, modeled ground temperatures at 10 m depth warm by about 5 °C and the active layer thickness increases by about 30%, in conjunction with a warming of average near-surface summer soil temperatures by 2 °C. While ground temperatures at 10 m depth remain below 0 °C until 2100 in all model grid cells, positive annual average temperatures are modeled at 1 m depth for a few years and grid cells at the end of this century. The ensemble of all 10 m model grid cells highlights the significant spatial variability of the ground thermal regime which is not accessible in traditional coarse-scale modeling approaches.
Linear Objects Detection on SAR Images

Allocation of linear structures on images is required to solve a large number of thematic problems of the Earth remote sensing. Roads and railways, power lines, pipelines, and borders of natural areas “landsea”, “forest-field”) are examples of such structures. It is known that traditional algorithms for linear targets and structures detection are not effective, because radar images have special distinctive features (i.e. speckle-noise), which complicate the target detection problems. In the paper neural network algorithm based on the Hough transform and application of Kohonen neural networks is suggested and researched. At the first stage, a radar image is transformed into a Hough plane, where linear targets give peak responses; then a Kohonen neural network is used to find these peaks. It is shown that the neural gas algorithm for the network weights adjustment is more suitable than the “Winner takes all” rule. Also, an exponential weight calibration function for better convergence is offered. Examples of real radar space images processing obtained by the RADARSAT-1 are given. Results of processing show that the suggested algorithm is suitable for linear targets detection on the radar images.
Electric properties of ice near solidification and melting temperature

The dielectric permittivity, conductivity and loss tangent of ice were measured for different thicknesses of the sample (0.1–4 mm). In this investigation, the measurement of thin samples can be treated as a laboratory test of surface properties and that of thick samples as a test of bulk properties. The measurements were carried out from 3.5 to –13.5°C with descending and growing temperature. Two domain Debye resonances were observed. The one at low frequency is interpreted as being associated with transversal mode, and the other, at higher frequency, is associated with longitudinal mode of proton domain. The resonance frequencies depend on sample size and temperature. Temperature hysteresis of resonance frequencies was observed. As the temperature grows starting from low temperature, the resonance frequencies move towards each other and finally the two modes join to form one mode. The dielectric constant associated with transversal mode is higher than 104. The dielectric constant associated with longitudinal mode is about 102. The dipole dielectric constant vanishes after solidification. As the temperature grows, the dipole dielectric constant grows too. Oscillation of dielectric permittivity and conductance for a small value of oscillator level was observed. The experimental data show that ice could be both a ferroelectric and a piezoelectric material.
UvA-DARE ( Digital Academic Repository ) Holography and wormholes in 2 + 1 dimensions

We provide a holographic interpretation of a class of three-dimensional wormhole spacetimes. These spacetimes have multiple asymptotic regions which are separated from each other by horizons. Each such region is isometric to the BTZ black hole and there is non-trivial spacetime topology hidden behind the horizons. We show that application of the real-time gauge/gravity duality results in a complete holographic description of these spacetimes with the dual state capturing the non-trivial topology behind the horizons. We also show that these spacetimes are in correspondence with trivalent graphs and provide an explicit metric description with all physical parameters appearing in the metric.
Sick of Your Job? – Negative Health Effects from Non-Optimal Employment

In an empirical study based on data from the German Socio-Economic Panel, the effect of job quality on individual health is analyzed. Extending previous studies methodologically to estimate unbiased effects of job satisfaction on individual health, it can be shown that low job satisfaction affects individual health negatively. In a second step, the underlying forces of this broad effect are disentangled. The analysis shows that the effects of job satisfaction on health run over the channels of job security and working hours above the individual limit. Job quality not only has a strong impact on mental health but physical health is affected as well. At the same time, health-damaging behavior including smoking and being overweight is not affected.
Coarsening of facetted two-dimensional islands by dynamic coalescence

We study the coarsening of two-dimensional 2D vacancy islands on a crystal surface by atomic-scale kinetic Monte Carlo simulations on an ensemble of meandering islands. The Brownian motion of islands is due to the motion of atoms within the islands, with the escape of atoms from islands prohibited by the presence of a step edge barrier. We find that the diffusion of individual islands and their size distribution qualitatively change for large bond energies or low temperatures, when the islands develop straight edges facets . The island diffusion coefficient becomes size independent and the size distribution becomes monotonously decreasing. The results of the kinetic Monte Carlo simulations are supported by numerical solutions of the Smoluchowski equations. We derive the kernel of the Smoluchowski equations for the 2D case taking into account the screening effects and find that the screening essentially alters the island size distribution.
Mean-square prefiltered generalized delayed decision feddback sequence detection

The Generalized Delayed Decision Feedback Sequence Detector (GDDFSD) is a scheme for detecting uncoded data corrupted by ISI and noise. The GDDFSD is a variant of the DDFSD, the variant being that in the GDDFSD multiple survivors are allowed for each state. In the paper, it is proposed to adopt as a front-end the mean-square whitened matched filter in place of the classical whitened matched filter. Simulation results show that our proposed design gives substantial benefits when a severe frequency selective channel is considered.
Product Reputation Analysis System Based on Partial Supervised Word Alignment Model

As increase in web network there is also increase in social, commercial product services and user interest their review for the product. When user wants to buy some products from the web they put their reviews and rating to the products. For another user who buy the products for which the rating and review system is very helpful for both user and organization. The review contains product feature and rating because of this product popularity decides. Reputation system has ratings for the product analysis. If large number of rating is present then there may be unsure review of product. Hence proposed system used good reputation system having precise sentiment and opinion word and opinion target.
Effect of the Classifier Training Set Size on Accuracy of Pattern Recognition

The paper determines the correlation between training set size and accuracy of neural handwritten recognition. The paper investigates and compares between four variant neural networks, it practices between two different sizes of training sets. The paper illustrates a novel technique contains two major algorithms; first one aims to locate Prospective Segmentation Points (PSP) within the word image, second aims to evaluate each PSP and determining the valid and invalid points. The technique implements four different classifiers and compares their results. To do so, the paper investigates the fusion equations to evaluate confidence values of each PSP, equations obtain a fused value of confidence values from three neural to report whether keep valid segment points (SP) or remove invalid one. The research tracks CPU times and accuracy of the algorithm, as well as, compares the performed experimental results of the classifiers with each other and with related works in the literature.
Estimating Seed Vigor by Sugar Exudates and Radicle Elongation

of germinability, were divided into 6 sublots for evaluation of sugar exudates. Empty seeds were removed from the lots before use. One-gram samples from each species-replication were placed in test tubes and surface-sterilized by adding 2 milliliters of 0.1 percent calcium hypochlorite. After soaking for 10 minutes, the seeds were rinsed and 15 milliliters of distilled water was added. The tubes were then capped and allowed to stand for 24 hours at room temperature ( 24 + 2 °C). After this imbibition period, duplicate analyses for sugars were run by the phenol-sulfuric acid method described by Dubois et al. (4). The percentage of transmittance of the resultant mixture was read on a spectrophotometer at 490 nanometers. Duplicate 100-seed samples from each species treatment replication were tested to determine percentage of germination. All tests were conducted in a seed testing laboratory according to test procedures of the Association of Official Seed Analysts (1). Seeds of longleaf and spruce pine that had germinated (radicles extended) in these tests were used to estimate vigor by measuring radicle growth. When sufficient numbers were available, about 10 seedlings from seeds that had germinated on the same date were used to measure radicle growth to the nearest millimeter. These meapeas (Pisum sativum L.) (8). Later research has supported this principle, and electrical conductivity of seed leachates is now included in the International Seed Testing Association's Handbook of Vigour Test Methods (6). Bonner and Vozzo (3) have reported that measurement of leachate conductivity provides valid estimates of seed quality of loblolly (Pinus taeda L.) and slash (P. elliottii Engelm.) pine. If exudates can be used to reliably estimate seed viability, they may also be of value in evaluating vigor. Such an indicator of seed vigor is needed, and none of consistent reliability has been developed for pine seeds. One that has been used with seeds of other genera is early seedling development. Although epicotyl growth is normally measured, root growth has also been related to seed vigor (7, 11). Root development would seem to be the better parameter to measure in pines because epicotyl growth is usually slow. This paper discusses an evaluation of sugar exudates and radicle growth as techniques for estimating the vigor of seeds of longleaf pine (P. palustris Mill.), spruce pine (P. glabra Walt.), and loblolly pines.
Conditions for optical parametric oscillation with a structured light pump

We investigate the transverse mode structure of the down-converted beams generated by a type-II optical parametric oscillator (OPO) driven by a structured pump. Our analysis focus on the selection rules imposed by the spatial overlap between the transverse modes of the three fields involved in the non-linear interaction. These rules imply a hierarchy of oscillation thresholds that determine the possible transverse modes generated by the OPO, as remarkably confirmed with experimental results.
Predicting English Test Anxiety: How Memorization and Critical Thinking Function?

Understanding how foreign language anxiety develops has become very important because of its influences on language learning and performance. The current study examines the levels of Omani students’ English language test anxiety and how these levels are influenced by the use of two learning strategies, memorization and critical thinking. The sample consisted of (250) students from different Omani school grades. The participants responded to three questionnaires relating to test anxiety, memorization, and critical thinking. The findings showed that these Omani school students use both learning strategies and experience slightly low levels of test anxiety. The regression model consisting of the two learning strategies explains 20% of variance in students’ test anxiety. As the students increased their use of these two learning strategies, their test anxiety decreased, and critical thinking was found more influential in decreasing students’ feeling of test anxiety. Implications of the findings to language teaching and learning are discussed.
Data access performance impact of a memory-centric radio network

of the master’s thesis Author Tero Lindfors Title Data access performance impact of a memory-centric radio network Degree programme Computer, Communication and Information Sciences Major Communications Engineering Code of major ELEC3029 Supervisor Prof. Tarik Taleb Advisor M.Sc. (Tech.) Jari Karppinen Date 18.09. 2018 Number of pages 67+2 Language English
GENDER AND ONLINE DISCOURSE IN THE PRINCIPLES OF ECONOMICS

Collaboration is the heart of online learning. Interaction among course participants brings excitement to the online environment and creates knowledge as a group activity. Impediments to active collaboration reduce group, as well as individual, potentialities. Past studies of online discussions have found differences in the style of female and male conversations that could impede the learning process. The conversational styles of female and male students in two online principles of economics classes were analyzed in the present study. The null hypothesis posited no difference in the styles of online discourse between female and male students. The null hypothesis was rejected, implying gender differences inconversational styles. The tone of male postings was more optimistic than the tone of female postings. Female conversations used words revealing social isolation and the rejection of social norms. The paper also discussed the issue of the male X-factor in the principles of economics from a sociolinguistic perspective.
Water Temperature Affects Athletes Drinking Behavior during Self-Paced Cycling in Hot Environment

Carvalho MV, Mendes TT, Andrade MT, Ramos GP, Maia-Lima A, Pereira ER, Amorim FT, Silami-Garcia E. Water Temperature Affects Drinking Behavior of Athletes during Self-Paced Cycling Exercise in the Heat. JEPonline 2016;19(6):137-144. The purpose of this study was to compare the athletes’ water behavior when receiving cool or warm water during a 40 km self-paced cycling in a hot environment. Ten male cyclists who exercised an average of 250 km·wk were subjected randomly to two experimental conditions during which they ingested water ad libitum at 10 or 37°C in a hot environment (35°C and 60% URA). Cold water influenced drinking behavior and increased total volume ingested and volume of water ingested per aliquot. However, the voluntary frequency of drinking was unchanged. During self-paced exercise in warm environment, the temperature of the water changes its palatability, stimulating higher fluid ingestion, but it does not affect the frequency of drinking.
Critical factors in vitrification-based cryopreservation of precision-cut liver slices

Precies-gesneden leverplakjes, PCLS genaamd, worden veel gebruikt als in vitro onderzoeksmethode met name in het onderzoek naar het metabolisme en toxische effecten van geneesmiddelen. Deze PCLS kunnen worden gemaakt van menselijk en dierlijk weefsel en moeten dan vers gebruikt worden. Succesvolle cryopreservatie van PCLS zou het mogelijk maken om een weefselbank op te zetten met PCLS van verschillende proefdieren en van de mens, wat een efficienter gebruik van het schaarse menselijke weefsel en tegelijk een vermindering van het proefdiergebruik zou bevorderen. Echter tot nu toe is de vitaliteit van PCLS na cryopreservatie niet goed genoeg, en zijn de factoren die bepalend zijn voor dit verlies aan vitaliteit niet goed onderzocht. Het doel van het onderzoek beschreven in dit proefschrift was om deze kritieke stappen in cryopreservatie door middel van vitrificatie van PCLS te identificeren en te begrijpen, met als uiteindelijk doel om een methode te ontwikkelen! waarmee PCLS kunnen worden gecryopreserveerd met behoud van functie en vitaliteit en om zo een weefsel bank te kunnen opzetten die voor onderzoek gebruikt kan worden. We gebruikten verschillende methoden om de vitaliteit en functionaliteit van ieder van de verschillende celtypen die in de leverplakjes aanwezig zijn, afzonderlijk te meten. Daarnaast onderzochten we het mechanisme van de schade die ontstaat door het afkoelen van het weefsel onder omstandigheden waarbij ijskristalvorming of schade door de vitrificatievloeistof minimaal was, door middel van analyse van het profiel van genexpressie. De resultaten van dit onderzoek hebben belangrijke informatie opgeleverd voor de ontwikkeling en verbetering van de methode voor cryopreservatie van menselijke en dierlijke weefsels.
Cortical entrainment: what we can learn from studying naturalistic speech perception

ABSTRACT The popular framework of cortical entrainment postulates that speech comprehension crucially depends on the continuous alignment of low-frequency cortical oscillatory activity with the amplitude envelope of perceived acoustic speech signals. The evidence for cortical entrainment mostly stems from tightly controlled experimental paradigms focusing on repeated perception of isolated sentences that feature a very constant speaking rate. However, these kinds of decontextualised and extremely regular stimuli do not reflect natural speech as we encounter it in real life. We thus advance the view that naturalistic experimental paradigms, utilising spontaneously produced speech as stimuli and suitable frequency-domain methodological tools, should be used to address an important question that remains open: whether cortical entrainment is observed during speech perception and comprehension in real-life communicative situations. In addition, we discuss how the phenomenon currently labelled as cortical entrainment might be confounded by a regular repetition of evoked responses.
Effect of Pretilachlor on the Mortality of Fish Gambusia

There is a growing concern over aquatic pollution because of its detrimental effects on biological life including human beings. The goal of the present study was to determine the acute toxicity of pretilachlor as potential dangerous organic pesticides to assess mortality effects of these chemicals to the gambusia in the form of LC . Fish samples (21 fish in each test group) were exposed to different concentrations of 50 pretilachlor (between 0-25ppm for pretilachlor) for 96 h. LC was determined with probite analysis. The 96h 50 toxicity tests showed 100% mortality in 25 ppm and no mortality in 5 ppm. Further researches are recommended to study the processes by which these chemicals affect physiology and histology of fish and their accumulation in fish tissues.