Search results for "Sampling"
showing 10 items of 788 documents
Unpredictability of fish recruitment: interannual variation in young-of-the-year abundance
2000
In 1989-1998, vendace larvae Coregonus albula were sampled in Finnish lakes following a stratified random sampling design. The abundance of young-of-the-year vendace after the first growing season was estimated using catch-per-unit-effort statistics. The number or total area of nursery places hardly limited the recruitment of vendace in the study lakes. The major proportion of prerecruit mortality of vendace occurred in the larval phase and larval sampling produced significant information on young-of-the-year survival. Although larval abundances and recruitment were clearly associated only in Lake Onkamo, generally high larval abundance was needed to produce high number of recruits.
Mate sampling behaviour of black grouse females (Tetrao tetrix)
1995
We studied female mate sampling behaviour in lekking black grouse (Tetrao tetrix). Females mainly visited males occupying territories in the centre of the lek with relatively large territories. They were also more likely to visit males that had high attendance. The same factors were also correlated with male mating success. A multiple regression model including these factors explained more of the variance in female visits per male (53%) than in mating success (33%). The pattern of female sampling conformed with a pool comparison (best-of-n) tactic. Such a tactic is expected if the costs of sampling are low. Females of high body mass visited more males than lighter females, however, which in…
Classification of Spanish Mosquitoes in Functional Groups
2011
Abstract We present a classification of Spanish mosquitoes according to their different life cycles. The bio-ecological parameters analyzed in our study were oviposition sites, overwintering stages, preferred hosts, and number of generations per year for each species. The results revealed 13 different functional groups. To assess the validity and robustness of the classification system, we analyzed the data from an intensive sampling carried out over a period of 4 years (2005–08) in eastern Spain. In this area, 9 of the 13 functional groups were found. The Jaccard cluster and the principal components analysis (between-group analysis method) revealed 3 different mosquito groups: the tree hol…
Robust estimation of mean electricity consumption curves by sampling for small areas in presence of missing values
2017
In this thesis, we address the problem of robust estimation of mean or total electricity consumption curves by sampling in a finite population for the entire population and for small areas. We are also interested in estimating mean curves by sampling in presence of partially missing trajectories.Indeed, many studies carried out in the French electricity company EDF, for marketing or power grid management purposes, are based on the analysis of mean or total electricity consumption curves at a fine time scale, for different groups of clients sharing some common characteristics.Because of privacy issues and financial costs, it is not possible to measure the electricity consumption curve of eac…
Slacking Off or Winding Down? An Experience Sampling Study on the Drivers and Consequences of Media Use for Recovery Versus Procrastination
2016
Today's constant availability of media content provides users with various recreational resources. It may also challenge self-control, however, once media exposure conflicts with other goals and obligations. How media users deal with these self-regulatory chances and risks in their daily lives is largely unknown. Our study addressed the predictors and consequences of recreational and procrastinatory media use using experience sampling methodology (N = 215; 1,094 media use episodes). Results suggest that trait (self-control, performance goal orientation) as well as state variables (exhaustion) are significant predictors of media use for recovery versus procrastination. Whereas recreational m…
Operam ludere: testimonios y equivalencias en latín
2018
espanolEl autor, partiendo de la base de que una misma idea puede representarse en numerosas expresiones y proverbios, realiza primeramente un estudio sobre los diversos testimonios transmitidos en latin de la expresion operam ludere , que viene a significar “ perd er el tiempo ”. Tras la descripcion de las citas que contienen esta expresion, se realiza una busqueda y explicacion de otras locuciones y proverbios latinos de significacion paralela. Finalmente se clasifican esas citas en una tabla por indice tematico y d e autores EnglishThis paper starts from the assumption that the same idea can be reflected in various expressions and proverbs in Latin. The paper offers as a first step an an…
Near IR stationary wave Fourier transform lambda meter in lithium niobate: multiplexing and improving optical sampling using spatially shifted nanogr…
2021
Several integrated optics solutions currently exist to develop monolithic, robust, and lightweight high-resolution spectrometers for spatial applications. An interesting option is generating a stationary wave inside a single-mode waveguide, and sampling the interference fringes using dielectric discontinuities on the surface of the waveguide. This allows the recording of the signal on a detector on top of the waveguide, and using dedicated Fourier transform methods to recover the spectrum of the source. All the difficulty is then linked to the length of the interferogram that is sampled. This determines the spectral resolution and the spacing between sampling centers, which are ultimately l…
Guide to Practical Work with the Monte Carlo Method
2002
The guide is structured such that we proceed from the “easy” simulation methods and algorithms to the more sophisticated. For each method the algorithms are presented by the technique of stepwise refinement. We first present the idea and the basic outline. From then on we proceed by breaking up the larger logical and algorithmic structures into smaller ones, until we have reached the level of single basic statements. Sometimes we may elect not to go to such a depth and the reader is asked to fill in the gaps.
Predicting the bioaccumulation of polyaromatic hydrocarbons and polychlorinated biphenyls in benthic animals in sediments
2016
There were two main objectives in this study. The first was to compare the accuracy of different prediction methods for the chemical concentrations of polyaromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in the organism, based on the measured chemical concentrations existing in sediment dry matter or pore water. The predicted tissue concentrations were compared to the measured ones after 28-day laboratory test using oligochaeta worms (Lumbriculus variegatus). The second objective was to compare the bioaccumulation of PAHs and PCBs in the laboratory test with the in situ bioaccumulation of these compounds. Using the traditional organic carbon-water partitioning model, tissue…
Sampled-Data Control of Spacecraft Rendezvous with Discontinuous Lyapunov Approach
2013
Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2013/814271 Open Access This paper investigates the sampled-data stabilization problem of spacecraft relative positional holding with improved Lyapunov function approach. The classical Clohessy-Wiltshire equation is adopted to describe the relative dynamic model. The relative position holding problem is converted into an output tracking control problem using sampling signals. A time-dependent discontinuous Lyapunov functionals approach is developed, which will lead to essentially less conservative results for the stability analysis and control…