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EN
The attenuation variability of hearing protector devices plays a primary role in determining compliance, or lack of, with occupational noise exposure limits. This study presents an estimate of the ear muff attenuation variability, which includes several factors (biological diversity, positioning, sound field, ageing) for which specific information from laboratory studies is available. A mean value of the attenuation variability for ear muffs σFR = 4.8 dB is found. This value is about 65% larger than the typical value measured according to existing test standards. Being marginally smaller than the mean variability resulting from field measurements, and certainly within the wide range of fluctuations of the latter, it represents a robust and reliable quantity for application in any workplace environment.
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Content available Uwagi o zmienności suewitów
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Suevite is the impact breccia rock with glass particles that attracts the attention of researches because of its broad variability. Many characteristics of the environment and impact process determine this attention, and, in consequence, various descriptions and names of the rock are presented in the literature. The Rochechouart impact structure is a good example of suevite or suevite-like rock diversity in its several localities (Rochechouart, Chassenon, LaValette, Montoume). The relationships between suevite components and target rocks can be exemplified by Kara and Popigai and other astroblemes. To simplify the classification of the rock, its main and more stable components (matrix, glass, clasts) should be considered. More detailed analysis of the suevite components can be used for sub-classifications, similarly as it is done for other Earth rocks. In addition, a short description of suevites from various astroblemes is presented. The possibility of the monomict suevite breccia creation is discussed.
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The execution variability and outcomes found in throwing actions have received special attention in numerous studies in recent years. The aim of this study was to analyze the effect of an unstable condition on velocity, accuracy and kinematics of movement in the seven metres throw in handball. Twenty-five young handball players took part in an experiment, throwing towards a target on a stable and an unstable surface. Each participant performed 32 throws, 16 for each situation. Linear variability of the dominant hand was assessed by 3D Motion Tracking. A radar sports gun was used to record the velocity of the ball and the throws were video recorded to establish their accuracy. Results showed significant decreases in throwing velocity in unstable conditions, but these did not significantly affect the accuracy achieved in performance. Differences were also found in movement kinematics between the two throwing conditions and relationships were found between kinematics, velocity and accuracy.
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According to Complex Dynamic Systems Theory (CDST), language is a complex dynamic system consisting of subsystems which show a lot of variability, especially during intensive development. Second language development is generally connected with an increase in complexity, accuracy and fluency but there are trade-offs within and between these language subcomponents. What is more, intra-individual variability, defined as differences in the level of developmental variables within individuals and between repeated measurements, is said to be an important developmental phenomenon. The aim of this article is to analyze the relationships between different measures of syntactic complexity, lexical complexity, accuracy and fluency, and to examine intra-individual variability with respect to the rate of development in longitudinal oral data provided by a good, average and poor language learner at the level of secondary school. Generally, the results of the study show some statistically significant differences between the learners in the development of these language subsystems but no such differences in intra-individual variability. Nevertheless, the study indicates a strong, positive correlation between the learners’ level of intra-individual variability and the rate of development of the language subsystems in speech at this level.
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In connection with IPGR participation in various national and international projects during the recent years, investigations have been conducted, in order to create a database of available old plant materials of grain legumes of Bulgarian origin. Different areas throughout Bulgaria with diverse relief, soil and climatic conditions have been visited. From the literature review and collected from previous studies data we identified the specific areas these crops occupy traditionally in the home garden and are sentimentally linked to family traditions. Questionnaires were developed, which intended to complement and update the existing information about location, farmer’s name, number cultivated species, usage, cooking recipes and storage. In this respect, numerous interviews with local people were conducted and were visited community centers, museums, schools and other organizations and institutions.
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The dynamic changes in selected heavy metal concentrations were analyzed in two ombrotrophic peat bogs from southern Poland: Puścizna Mała (PK) and Puścizna Krauszowska (PM). The highest contents of Pb and Zn occur at the top of profiles examined: 115.36 mg/kg (PM1), 90.61 mg/kg (PM2), 182.40 mg/kg (PK1), 121.68 mg/kg (PK2) and 127.43 mg/kg (PM1), 89.73 mg/kg (PM2), 170 mg/kg (PK1), 130.4 mg/kg (PK2), respectively. Concentrations of copper are similar to those of local soils varying from 9.4 to 12.8 mg/kg. Cadmium strongly varies with depth, which indicates distinct mobility of this element. Two peaks of elevated Fe concentrations are observed at the top and bottom of the Puścizna Mała profile, while the maximum in Puścizna Krauszowska was at the top of the peat bog. The Ti content distinctly varies with depth and correlates with the ash content (R2 = 0.91-0.99). The strongest and positive correlation is observed between Zn-Pb and Ti-Pb contents. The significant differences of metal concentrations are noted between the profiles, which is probably connected with a rate of peat accumulation and plant composition of the profiles investigated, as well as with their disturbance by human activity.
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The article provides design and engineering analysis of groups of packages. The relationship between the functional units of packaging machines and related groups designs packages is traced. The method for calculation of the versatility rate of the packaging machine depending on its structure is offered.
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Content available remote Demography of Clethrionomys glareolus in Belgium
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Bank vole populations were followed for several years on two grids (on a fenced grid, preventing dispersal during 11 years and on an open grid for 7 years) using standard Capture-Mark-Recapture methods. The collected data allow us to obtain a good knowledge on several demographic processes within populations. Here we focus mainly on reproduction. On both grids we observed strong seasonal and inter-annual variations in the density of bank voles, characteristic for non-cyclic bank vole populations. The inter-annual variation in the dynamics of bank vole populations in Belgium were to a great extend mast-dependent. The influence of heavy seed crops on demographic parameters was different for the two sexes. Winter survival of males was much better in years with heavy mast crops whereas no such relation could be found for females. During the breeding period, several reproductive traits varied considerably between years and seasons and some of them can be directly related to density (f.i. maturation rate, pregnancy rate). In years with low densities demographic traits are most variable, especially in females, and other factors than density could have overriding effects.
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The main objective of this study was to analyze the motor variability in the performance of the tennis serve and its relationship to performance outcome. Seventeen male tennis players took part in the research, and they performed 20 serves. Linear and non-linear variability during the hand movement was measured by 3D Motion Tracking. Ball speed was recorded with a sports radar gun and the ball bounces were video recorded to calculate accuracy. The results showed a relationship between the amount of variability and its non-linear structure found in performance of movement and the outcome of the serve. The study also found that movement predictability correlates with performance. An increase in the amount of movement variability could affect the tennis serve performance in a negative way by reducing speed and accuracy of the ball.
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Not just diachronic change or synchronic variability in linguistic structure, but also the shape of speakers’ expressive strategies for navigating natural verbal interaction can be seen as reflections of the fundamental human capacity for adapting to novel communicative circumstances. The adjustments are observable at all layers of language — sounds, prosody, lexical changes, shifts in grammatical organization — and also pose questions concerning adaptation at both the individual and community levels. In this introductory framing of the present volume, the conceptual underpinnings of the quest for adequate explanations of adaptive processes are consistent with a set of assumptions that are associated with, broadly speaking, ‘socio-cognitive’ approaches to language: (i) socio-pragmatic and cultural grounding of verbal interaction, (ii) reference to domain-general cognitive capacities, and (iii) emergence of linguistic categories and their organization from recurring patterns of use. Linguistic analysis focused on the adaptive aspects of language and language use thus aims at capturing the speakers’ interactional competence; this includes both narrowly linguistic aspects and non-linguistic patterns of behavior, which, taken together, help us understand better all the factors involved in successful communication.
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The results showed the eggs of various species to differ both in terms of their dimensions and volume, the differences being 5– and more than 70–fold, respectively.
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Monthly, seasonal and annual values for outflow and outflow coefficient measured over ten years for a small agricultural catchment are presented. The catchment is situated at 723-822 m a.s.l and covers 40.57 ha. Mean annual precipitation total during the investigated period was 850 mm and mean annual air temperature was 5.9oC. Average annual overall outflow from the catchment was 446 mm, i.e. 52% of total precipitation. The outflow varied considerably in relation to rainfall/snowfall/snowmelt conditions. The highest monthly outflow was in March and the lowest in November (20.6% and 3.8% of the annual outflow, respectively). Considerable variability of the outflow from the catchment is caused mainly by frequent torrential rains in summer and infiltration of water into groundwater reserves during spring snowmelt.
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This article presents the results of studies conducted on the variability of thermal and precipitation conditions in Poland in the second half of the 20th century, especially taking into consideration periods which were unfavorable for agricultural production. Averaged spatial temperatures and precipitation totals from consecutive years 1951 to 2000 were used. A significant increase in spring temperatures was noted, while the winters also became warmer. This had a significant effect upon the change of the thermal vegetation period's duration. No changing trends were noted with regard to the amount of precipitation.The analysis of the seasonal structure during the anomalous years, with regard to temperature and the amount of precipitation, made it possible to pinpoint years particularly unfavorable for agricultural production. There was a certain repeatability of unfavorable conditions, tied to the existence of a relatively stable 8-year cycle of temperature change, which was especially noticeable during the wintertime. During the last two decades of the 20th century, high temperature values, occurring also in the summertime, in combination with insufficient precipitation, contributed to the occurrence of dry spells and even periods of drought. The occurrence of dry spells during the vegetation period and the extreme shortening of the vegetation period have a significant effect upon the amount of grain crop production.
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Fundamental to complex dynamic systems theory is the assumption that the recursive behavior of complex systems results in the generation of physical forms and dynamic processes that are self-similar and scale-invariant. Such fractal-like structures and the organismic benefit that they engender has been widely noted in physiology, biology, and medicine, yet discussions of the fractal-like nature of language have remained at the level of metaphor in applied linguistics. Motivated by the lack of empirical evidence supporting this assumption, the present study examines the extent to which the use and development of complex syntax in a learner of English as a second language demonstrate the characteristics of self-similarity and scale invariance at nested timescales. Findings suggest that the use and development of syntactic complexity are governed by fractal scaling as the dynamic relationship among the subconstructs of syntax maintain their complexity and variability across multiple temporal scales. Overall, fractal analysis appears to be a fruitful analytic tool when attempting to discern the dynamic relationships among the multiple component parts of complex systems as they interact over time.
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Content available Individual Fit Testing of Hearing Protection Devices
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While hearing protection devices (HPD) have been the last and often only line of defense against noiseinduced hearing loss in the workplace, their performance has been suspect. Laboratory evaluations have not proven to predict the actual performance of HPD in the field. Individual fit testing of HPD will allow the determination of HPD performance on individual workers, and this will improve the ability to select HPD appropriate for given noise exposures and intervene with workers to ensure sufficiency in HPD performance. A modified microphone-in-real-ear (F-MIRE) has been adapted to test a variety of HPD quickly and reliably in situ. A dual-element microphone and software combination permits reliable noise reduction measurements. Statistically developed compensation factors permit direct comparison of F-MIRE predicted personal attenuation ratings to traditional laboratory measures of HPD performance using real-ear-attenuation-at-threshold assessments.
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The paper studies variations in the water level and surface temperature of coastal lagoons along the southern and south-eastern shores of the Baltic Sea: the Curonian Lagoon, Vistula Lagoon, and Darss-Zingst Bodden Chain. Linear regressions for annual mean water level variations showed a positive trend in water level, but at different rates. The highest rate during the period between 1961-2008 was recorded for the Curonian and Vistula lagoons (~4 mm year-1), the lowest for the Darss-Zingst Bodden Chain (approximately ~ 1 mm year-1). The warming trend of the mean surface water temperature in the lagoons was 0.03°C year-1 in the period 1961-2008. Moreover, the variability in annual water temperature and sea level as well as their extreme values have increased most dramatically since the 1980s.
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Content available remote Movements that are both variable and optimal
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This brief review addresses two major aspects of the neural control of multi-element systems. First, the principle of abundance suggests that the central nervous system unites elements into synergies (co-variation of elemental variables across trials quantified within the framework of the uncontrolled manifold hypothesis) that stabilize important performance variables. Second, a novel method, analytical inverse optimization, has been introduced to compute cost functions that define averaged across trials involvement of individual elements over a range of values of task-specific performance variables. The two aspects reflect two features of motor coordination: (1) using variable solutions that allow performing secondary tasks and stabilizing performance variables; and (2) selecting combinations of elemental variables that follow an optimization principle. We suggest that the conflict between the two approaches (a single solution vs. families of solutions) is apparent, not real. Natural motor variability may be due to using the same cost function across slightly different initial states; on the other hand, there may be variability in the cost function itself leading to variable solutions that are all optimal with respect to slightly different cost functions. The analysis of motor synergies has revealed specific changes associated with atypical development, healthy aging, neurological disorders, and practice. These have allowed formulating hypotheses on the neurophysiological mechanisms involved in the synergic control of actions.
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