Wyniki wyszukiwania - Biblioteka Nauki

1

Imputation of missing values by using raw moments

100%

Sohail M. U. , Shabbir J. , Sohil F.

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tom 20

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nr 1

21-40

EN

The estimation of population parameters might be quite laborious and inefficient, when the sample data have missing values. In comparison follow-up visits, the method of imputation has been found to be a cheaper procedure from a cost point of view. In the present study, we can enhance the performance of imputation procedures by utilizing the raw moments of the auxiliary information rather than their ranks, especially, when the ranking of the auxiliary variable is expensive or difficult to do so. Equations for bias and mean squared error are obtained by large sample approximation. Through the numerical and simulation studies it can be easily understood that the proposed method of imputation can outperform their counterparts.

2

An alternative methodology for imputing missing data in trials with genotype-by-environment interaction: some new aspects

75%

Arciniegas-Alarcón S. , García-Peña M. , Krzanowski W. J. , Santos Dias C. T. d.

Biometrical Letters

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2014

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tom 51

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nr 2

75-88

EN

A common problem in multi-environment trials arises when some genotypeby- environment combinations are missing. In Arciniegas-Alarcón et al. (2010) we outlined a method of data imputation to estimate the missing values, the computational algorithm for which was a mixture of regression and lower-rank approximation of a matrix based on its singular value decomposition (SVD). In the present paper we provide two extensions to this methodology, by including weights chosen by cross-validation and allowing multiple as well as simple imputation. The three methods are assessed and compared in a simulation study, using a complete set of real data in which values are deleted randomly at different rates. The quality of the imputations is evaluated using three measures: the Procrustes statistic, the squared correlation between matrices and the normalised root mean squared error between these estimates and the true observed values. None of the methods makes any distributional or structural assumptions, and all of them can be used for any pattern or mechanism of the missing values.

3

Neuro-rough-fuzzy approach for regression modelling from missing data

75%

Simiński K.

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nr 2

461-476

EN

Real life data sets often suffer from missing data. The neuro-rough-fuzzy systems proposed hitherto often cannot handle such situations. The paper presents a neuro-fuzzy system for data sets with missing values. The proposed solution is a complete neuro-fuzzy system. The system creates a rough fuzzy model from presented data (both full and with missing values) and is able to elaborate the answer for full and missing data examples. The paper also describes the dedicated clustering algorithm. The paper is accompanied by results of numerical experiments.

4

Różne wymiary odpowiedzialności prawnej

63%

Zalewska M.

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tom 77

7-10

EN

The legal liability is the issue of vast complexity and hence worth to analyze both on theoretical and practical level. The main goal is to analyze of one of the understandings of legal responsibility, imputation, proposed by Hans Kelsen. Therefore, first the concept of imputation will be described. Secondly, the mechanism will be revealed, which transforms imputation into legal responsibility. The conclusion includes the notion of incompleteness of Pure Theory of Law in application of law field.

PL

Odpowiedzialność prawna jest złożonym zagadnieniem, wartym przeanalizowania zarówno na poziomie teoretycznym, jak i w odniesieniu do konkretnych przypadków praktycznych. Celem niniejszego artykułu jest analiza jednego z ujęć odpowiedzialności prawnej, które zaproponował Hans Kelsen. Zostanie zatem opisana konstrukcja zarachowania, a następnie pokazany mechanizm przełożenia zasady zarachowania na odpowiedzialność prawną. Wnioski bazują na stwierdzeniu niekompletności „czystej teorii prawa” w zakresie stosowania prawa.

5

Koncepcja zachowań strategicznych na lokalnym rynku surowcowym w modelu gry n-osobowej - zarys problemu

63%

Krzak M.

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2012

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tom T. 28, z. 2

67-86

PL

Rynki surowcowe, pomimo wielu zazwyczaj wspólnych cech z innymi rynkami, są rynkami osobliwymi, a ich funkcjonowanie odbiega niekiedy od prawideł wolnego rynku. Wynika to ze specyfiki pozyskania dobra będącego przedmiotem obrotu handlowego. Zmiany podaży wielu strategicznych surowców mineralnych są na ogół znacznie wcześniej sygnalizowane (wieloletni cykl inwestycyjny od rozpoznania złoża do udostępnienia górniczego), rozwijają się wolno i nieelastycznie. Zapotrzebowanie na surowce pospolite ma często wyraźny, koniunkturalny charakter. Wspólną cechą dla rynków surowcowych, jak i rynków pozostałych dóbr jest jednakże fakt, iż są one miejscem nieustannej rozgrywki, a zachowanie poszczególnych podmiotów można na ogół sprowadzić do dwóch typów strategii: konkurencji lub kooperacji. W artykule przypomniano znany z literatury model gry związany z rynkiem ropy naftowej. Opierając się na trzypodmiotowym rynku producentów kruszyw podjęto próbę modelowania zachowań przedsiębiorców. W analizie wykorzystano założenia teorii gier n-osobowych, które umożliwiają ocenę i zasadność tworzenia różnorodnych koalicji. Pokazano możliwe strategie działania, wynikające zarówno ze współpracy zakładów jak i jej zaniechania. Dla ewentualnych aliansów oszacowano możliwe do osiągnięcia wypłaty i zaproponowano ich podział pomiędzy uczestników tworzących koalicję.

EN

Mineral markets, in spite of many common features with other goods markets, are distinctive. Their functioning sometimes deviates from the rules of the free market. This feature results from the specificity of acquiring the good being an object of trade. In general, changes in the supply of strategic raw materials are indicated earlier (characterized by a lengthy investment cycle from deposit reconnaissance to mining development), develop slowly, andare inelastic. Demand for common mineral raw materials often has a clear and economic character. However, mineral markets as well as markets of other goods have a common feature - the fact that both are a place where an incessant game is being played. In general, two types of strategic behaviours are distinguished: competition or cooperation. This paper recalls an existing model known as the oil market game. Based on a three-entity market of aggregate producers, an attempt has been made to model entrepreneurs' behaviour. The analysis applies n-person game theory. Game theory enables the evaluation of diverse potential coalitions forming. Possible strategies of activity coming from the prospect of cooperation (or its omission) are presented. Expected payoffs are estimated for possible alliances. Proposals for the division of the payoffs among the participants forming the coalition are also suggested.

6

Comparison of incomplete data handling techniques for neuro-fuzzy systems

63%

Sikora M. , Simiński K.

Computer Science

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2014

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tom Vol. 15 (4)

441--458

EN

Real-life data sets sometimes miss some values. The incomplete data needs specialized algorithms or preprocessing that allows the use of the algorithms for complete data. The paper presents a comparison of various techniques for handling incomplete data in the neuro-fuzzy system ANNBFIS. The crucial procedure in the creation of a fuzzy model for the neuro-fuzzy system is the partition of the input domain. The most popular approach (also used in the ANNBFIS) is clustering. The analyzed approaches for clustering incomplete data are: preprocessing (marginalization and imputation) and specialized clustering algorithms (PDS, IFCM, OCS, NPS). The objective of our research is the comparison of the preprocessing techniques and specialized clustering algorithms to find the the most-advantageous technique for handling incomplete data with a neuro-fuzzy system. This approach is also the indirect validation of clustering.

7

The problem of imputation of the missing data from the continuous counts of road traffic

63%

Spławińska M.

Archives of Civil Engineering

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2015

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tom Vol. 61, nr 1

131--145

EN

Missing traffic data is an important issue for road administration. Although numerous ways can be found to impute them in foreign literature (inter alia, the most effective method, that is Box-Jenkins models), in Poland, still only proven and simplified methods are applied. The article presents the analyses including an assessment of the completeness of the existing traffic data and works related to the construction of SARIMA model. The study was conducted on the basis of hourly traffic volumes, derived from the continuous traffic counts stations located in the national road network in Poland (Golden River stations) from the years 2005 – 2010. As a result, the proposed model was used to impute the missing data in the form of SARIMA (1.1,1)(0,1,1)168. The newly developed model can be used effectively to fill in the missing required days of measurement for estimating AADT by AASHTO method. In other cases, due to its accuracy and laboriousness of the process, it is not recommended.

8

Missing data estimation based on the chaining technique in survey sampling

63%

Singh Thakur N. , Shukla D.

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tom 23

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nr 4

91-111

EN

Sample surveys are often affected by missing observations and non-response caused by the respondents' refusal or unwillingness to provide the requested information or due to their memory failure. In order to substitute the missing data, a procedure called imputation is applied, which uses the available data as a tool for the replacement of the missing values. Two auxiliary variables create a chain which is used to substitute the missing part of the sample. The aim of the paper is to present the application of the Chain-type factor estimator as a means of source imputation for the non-response units in an incomplete sample. The proposed strategies were found to be more efficient and bias-controllable than similar estimation procedures described in the relevant literature. These techniques could also be made nearly unbiased in relation to other selected parametric values. The findings are supported by a numerical study involving the use of a dataset, proving that the proposed techniques outperform other similar ones.

9

Computer-Intensive Methods in Traffic Safety Research

51%

Harold S.

International Journal of Occupational Safety and Ergonomics

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2002

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tom Vol. 8, No. 3

353--363

EN

The analysis of traffic safety data archives has improved markedly with the development of procedures that are heavily dependent upon computers. Three such procedures are described here. The first procedure involves using computers to assist in the identification and correction of invalid data. The second procedure makes greater computational demands, and involves using computerized algorithms to fill in the ‘‘gaps’’ that typically occur in archival data when information regarding key variables is not available. The third and most computer-intensive procedure involves using data mining techniques to search archives for interesting and important relationships between variables. These procedures are illustrated using examples from data archives that describe the characteristics of traffic accidents in the USA and Australia.

10

Digital population and housing census - the experience of Serbia

38%

Kovačević M. , Nikić M. , Josipović B. , Lakčević S. , Pantelić V. , Mitrović N. , Kolaković A. , Korovićh P.

Wiadomości Statystyczne. The Polish Statistician

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2023

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tom 68

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nr 10

49-70

PL

Celem artykułu jest przedstawienie doświadczeń Republiki Serbii w zakresie organizacji Powszechnego Spisu Ludności, Gospodarstw Domowych i Mieszkań 2022, ze szczególnym uwzględnieniem zagadnień dotyczących zatrudnienia personelu, ram prawnych i finansowania tego badania oraz warunków jego udanej realizacji. Praca skupia się na strategicznych decyzjach w sprawie zbierania danych oraz zastosowania technik informatycznych, takich jak: wykorzystanie danych przestrzennych, cyfrowe metody uzyskiwania danych, uczenie maszynowe, łączenie rekordów czy system monitorujący, mających na celu sprostanie wyzwaniom związanym ze spisem. Autorzy poruszają także kwestie niedostatecznego pokrycia spisu oraz wykorzystania rejestrów administracyjnych do imputacji danych. Ponadto poświęcają uwagę opracowaniu i udoskonalaniu statystycznej ewidencji ludności, dokładności danych, obniżeniu kosztów i zwiększeniu efektywności badania. Główny Urząd Statystyczny Republiki Serbii przeprowadził spis powszechny w sposób cyfrowy, łącząc ten mechanizm z metodami tradycyjnymi (z wyłączeniem samospisu) i posiłkując się rejestrami administracyjnymi w celu imputacji danych. Metoda ta jest w artykule rekomendowana jako najefektywniejszy sposób uzyskania precyzyjnych i wyczerpujących informacji na temat populacji, w tym jej charakterystyki demograficznej, rozmieszczenia przestrzennego i liczebności.

EN

The aim of the paper is to present the experience of the Republic of Serbia in conducting the 2022 Census of Population, Households and Dwellings, focusing on the employment, legal framework and financing of the census as well as on its successful implementation. It discusses strategic decisions on data collection and the integration of information technology - including geospatial data, data collection techniques, machine learning, record linkage and monitoring system - to overcome the challenges posed by the census. The paper addresses the census undercoverage, explores the use of administrative data for item imputation, and examines the development of a statistical population register. The study demonstrates the benefits of adopting a digital-census approach: significant improvement of accuracy, cost reduction and acquired expeditiousness. The Statistical Office of the Republic of Serbia conducted a digital census combined with traditional methods, excluding self-enumeration, along with the use of administrative data for item imputation, and recommends this approach as the most effective way to obtain precise and comprehensive information about a population, including its demographic characteristics, geographic distribution and overall size.