Search results for "sampling"
showing 10 items of 788 documents
Crustacea Decapoda from Ustica (Southern Tyrrhenian Sea): species distribution and sampling approach.
2011
The decapod crustacean fauna of Ustica Island (Sicily, southern Tyrrhenian Sea) has been investigated in summer 2002 with the aid of many different sampling methods: suction device, pushnet, skid trawl, trammel net, traps, underwater observation, interviews. All the substrata occurring around the island from 0 to about -30 m were surveyed: midlittoral rock, infralittoral rock, pebbles, seagrass (Posidonia oceanica) bed, sand, detritic bottom, submerged cave. Fiftyseven species were collected in the investigated localities. Abundance and frequency of all species in the samples and in each surveyed biotope are given. The performance of each sampling method has been evaluated, in terms of numb…
Information and communication technologies and teacher education in the new paradigms of higher education
2018
Abstract Media use in the teaching process occurs in several forms. Information and communication technologies can be used as work equipment and teaching aids, as well as tools or curriculum units, particularly in higher education. Technological changes and new information technologies, in addition to substantive knowledge of the material, require from teachers creativity, knowledge, and the skills of the didactic design of teaching using modern multimedia tools. In Croatia, there is a lack of research aimed at assessing the initial state of computer literacy within the higher education institutions. The aim of this study was to determine the level of knowledge and digital competence of (no…
Ba/Ca ratios in shells of Arctica islandica —Potential environmental proxy and crossdating tool
2017
Abstract Ba/Ca shell time-series of marine bivalves typically show flat background levels which are interrupted by erratic sharp peaks. Evidence from the literature indicates that background Ba/Ca shell ratios broadly reflect salinity conditions. However, the causes for the Ba/Ca shell peaks are still controversial and widely debated although many researchers link these changes to primary productivity, freshwater input or spawning events. The most striking feature is that the Ba/Ca shell peaks are highly synchronous in contemporaneous specimens from the same population. For the first time, we studied Ba/Ca shell in mature and ontogenetically old (up to 251 year-old) specimens of the long-li…
The Critical Role of Morale in Ukraine’s Fight against the Russian Invasion
2020
The role of morale, also known as esprit de corps, in a high technology environment of the 21st century warfare, is poorly understood. The purpose of the study is to seek evidence for the proposition that the Ukraine’s population and military forces morale has neutralized the asymmetric difference in the military force of the two countries. The academic and practical implications have the potential to refocus military practice. An exploratory qualitative research method using theoretical sampling was used in this study. The study finds significant evidence for high morale as a balancing factor in the asymmetric differences of Russia and Ukraine, which explains Ukraine’s success against grea…
Conformational equilibrium of chorismate. A QM/MM theoretical study combining statistical simulations and geometry optimisations in gas phase and in …
2003
We report a theoretical study on the conformational equilibrium of chorismate that precedes its rearrangement to prephenate, an important enzyme-catalyzed reaction. In first place we show that the usual classification of chorismate conformers based on the relative position of the hydroxyl and ether bridge, pseudo-diaxial and pseudo-diequatorial, is not the only relevant factor from the point of view of the a posteriori rearrangement. Here we also analyse another complementary geometrical classification based on the interatomic distance between the carbon atoms to be bounded. Using the umbrella sampling approach and this distance as distinguished internal reaction coordinate, the gas phase A…
Bayesian Hierarchical Models for Random Routes in Finite Populations
1996
In many practical situations involving sampling from finite populations, it is not possible (or it is prohibitely expensive) to access, or to even produce, a listing of all of the units in the population. In these situations, inferences can not be based on random samples from the population. Random routes are widely used procedures to collect data in absence of well defined sampling frames, and they usually have either been improperly analyzed as random samples, or entirely ignored as useless. We present here a Bayesian analysis of random routes that incorporates the information provided but carefully takes into account the non- randomness in the selection of the units.
Calculate Pulse from Touch Error Free PPG Signal with 2ndOrder Butterworth Filter
2021
With the ongoing heart problems of the population worldwide, the medical requirements of the people are expected to increase. Electrocardiogram (ECG) is one of the proven to capture the heart response signal to assess the electrical and muscular functions of the heart. The ECG setup is expensive and needs proper training, and of course, it is not instant. For fast, accurate heart parameter monitoring, scientists pay attention to the photoplethysmogram signal (PPG), based on the light intensity of a particular wavelength. Android smartphone with a good quality camera has come to ordinary people's reach and has become one of the most necessary and rugged devices for today and future generatio…
Intra-urban residential differentiation in the post-Soviet city: the case of Riga, Latvia
2014
Cities in many Central and Eastern European (CEE) countries have transformed rapidly since the political and socio-economic restructuring started in the early 1990s. Economi reforms, growing income inequalities, changes in housing system and selective residential mobility are resulting in increasing socio-spatial differentiation among urban neighbourhoods also in Riga. In addition, litt le is known about the ethnic dimension of intra-urban residential differentiation, despite the existence of sizeable minority populations. The focus on ethnicity is important, since Riga is the only capital city in the Baltic States where the ethnic majority is outnumbered by the non-Latvian minority. This p…
An analysis of the bias of variation operators of estimation of distribution programming
2018
Estimation of distribution programming (EDP) replaces standard GP variation operators with sampling from a learned probability model. To ensure a minimum amount of variation in a population, EDP adds random noise to the probabilities of random variables. This paper studies the bias of EDP's variation operator by performing random walks. The results indicate that the complexity of the EDP model is high since the model is overfitting the parent solutions when no additional noise is being used. Adding only a low amount of noise leads to a strong bias towards small trees. The bias gets stronger with an increased amount of noise. Our findings do not support the hypothesis that sampling drift is …
The Tax Justice Network-Africa v Cabinet Secretary for National Treasury & 2 Others: A Big Win for Tax Justice Activism?
2019
This paper develops an optimization model for selecting a large subsample that improves the representativeness of a simple random sample previously obtained from a population larger than the population of interest. The problem formulation involves convex mixed-integer nonlinear programming (convex MINLP) and is therefore NP-hard. However, the solution is found by maximizing the “constant of proportionality” – in other words, maximizing the size of the subsample taken from a stratified random sample with proportional allocation – and restricting it to a p-value high enough to achieve a good fit to the population of interest using Pearson’s chi-square goodness-of-fit test. The beauty of the m…