Search results for "Estimation"
showing 10 items of 924 documents
Reconstruction of urban sites from photos
2019
Abstract. This paper reports the results of an experiment that aims at the virtual reconstruction of a urban site that has been partially reshaped during the 20th century; the reconstruction process is based on period photos. The chosen case study is the eldest harbour of Palermo, named ‘Cala’; the site was bombed during World War II and new buildings took the place of the ruined ones. Two period photos, taken from an aircraft, document the buildings that were destroyed by bombs. The 3D restitution process used the ‘inverse’ projection from period photos (2D) to the virtual space (3D) ; the first step was therefore addressed to the calculation of the inner parameters (focal length, principa…
Sequential and joint hydrogeophysical inversion using a field-scale groundwater model with ERT and TDEM data
2013
Abstract. Increasingly, ground-based and airborne geophysical datasets are used to inform groundwater models. Recent research focuses on establishing coupling relationships between geophysical and groundwater parameters. To fully exploit such information, this paper presents and compares a joint hydrogeophysical inversion (JHI) approach and sequential hydrogeophysical inversion (SHI) approach to inform a field-scale groundwater model with Time Domain Electromagnetic (TDEM) and Electrical Resistivity Tomography (ERT) data. The implemented SHI coupled inverted geophysical models with groundwater parameters, where the strength of the coupling was based on geophysical parameter resolution. To t…
Estimation of synthetic flood design hydrographs using a distributed rainfall–runoff model coupled with a copula-based single storm rainfall generator
2014
Abstract. In this paper a procedure to derive synthetic flood design hydrographs (SFDH) using a bivariate representation of rainfall forcing (rainfall duration and intensity) via copulas, which describes and models the correlation between two variables independently of the marginal laws involved, coupled with a distributed rainfall–runoff model, is presented. Rainfall–runoff modelling (R–R modelling) for estimating the hydrological response at the outlet of a catchment was performed by using a conceptual fully distributed procedure based on the Soil Conservation Service – Curve Number method as an excess rainfall model and on a distributed unit hydrograph with climatic dependencies for the …
Computation of vertically averaged velocities in irregular sections of straight channels
2015
Abstract. Two new methods for vertically averaged velocity computation are presented, validated and compared with other available formulas. The first method derives from the well-known Huthoff algorithm, which is first shown to be dependent on the way the river cross section is discretized into several subsections. The second method assumes the vertically averaged longitudinal velocity to be a function only of the friction factor and of the so-called "local hydraulic radius", computed as the ratio between the integral of the elementary areas around a given vertical and the integral of the elementary solid boundaries around the same vertical. Both integrals are weighted with a linear shape f…
Effect Declines Are Systematic, Strong, and Ubiquitous: A Meta-Meta-Analysis of the Decline Effect in Intelligence Research
2019
Empirical sciences in general and psychological science in particular are plagued by replicability problems and biased published effect sizes. Although dissemination bias-related phenomena such as publication bias, time-lag bias, or visibility bias are well-known and have been intensively studied, another variant of effect distorting mechanisms, so-called decline effects, have not. Conceptually, decline effects are rooted in low initial (exploratory) study power due to strategic researcher behavior and can be expected to yield overproportional effect declines. Although decline effects have been documented in individual meta-analytic investigations, systematic evidence for decline effects in…
Difficulty of getting accurate and precise estimates of population size: The case of the Siberian flying squirrel in Finland
2008
Accurate estimates of population size and distribution are a prerequisite for effective management of populations, but for most species a reliable estimation of the absolute population size is very difficult. In 1998, the Finnish Ministry of Environment set up a working group to plan a national-level survey for estimation and monitoring of the population size of Siberian flying squirrel (Pteromys volans). In 2006, the population size was reported to be 143 000 females. However, evaluation of the magnitude of possible biases was not attempted. Our aim was to test the population size estimate by conducting a resampling study with the methods of the national survey on an eartagged population o…
Projekty logistyki miasta – metoda szacunkowa oceny ryzyka
2017
W artykule przedstawiono zagadnienia projektów w obszarze logistyki miasta, które realizowane są nie tylko w warunkach niepewności, ale także ograniczeń budżetowych. Wskazano, że dążenie do równoważenia nakładów i efektów stwarza konieczność oceny zasadności projektu oraz ryzyka związanego z realizacją przyjętych celów w zakresie czasu, kosztu, zakresu i jakości inwestycji. Jednak brak obowiązku ustawowego oceny ryzyka skłania do poszukiwania takich metod, które nie będą generowały dodatkowych kosztów i dostarczą szybkich wyników, dlatego w artykule zaprezentowano metodę szacunkową oceny ryzyka projektów, bazującą na subiektywnych ocenach ekspertów. Wskazano jej główne zalety i pokazano pro…
Toolbox for Distance Estimation and Cluster Validation on Data With Missing Values
2022
Missing data are unavoidable in the real-world application of unsupervised machine learning, and their nonoptimal processing may decrease the quality of data-driven models. Imputation is a common remedy for missing values, but directly estimating expected distances have also emerged. Because treatment of missing values is rarely considered in clustering related tasks and distance metrics have a central role both in clustering and cluster validation, we developed a new toolbox that provides a wide range of algorithms for data preprocessing, distance estimation, clustering, and cluster validation in the presence of missing values. All these are core elements in any comprehensive cluster analy…
Double index recursive models
1994
The purpose of this document is to study the model belongs to the family of structural equation models with data varying both accross individuals (sectors) and in time. A complete theoretical analysis is developed in this work for the case of a recursive structure. Maximum likelihood estimation and Zellner's "seemingly unrelated equations" estimators (iterated or not) are presented and their asymptotic properties are carefully derived.The application of the estimation methods to the economy morocco produced statistically significant and economic meaningful results. Through a test of exogeneity, the recursivity of the system is confirmed. Policy recommendations are discussed and analyzed.
Analysis of Relationship between Net Wage and Consumer Price Index
2013
Abstract In the present paper is presented an econometric analysis of the relationship between net salary and consumer price index. After a brief historical overview will be review the calculating statistics for selected variables and coefficients and will be presented the obtained values. We will study the relationship between variables. It will be realized the cloud of points and will be applied Fisher test. The intensity of selected variables will be study too and some forms of relationship between the two chose variables will be done. Student test is applied. It will be performed the parameter estimation for regression functions and Akaike's criterion will be applied. The homoscedastici…