Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "outlier" wg kryterium: Temat


Tytuł:
Anomaly pattern detection in streaming data based on the transformation to multiple binary-valued data streams
Autorzy:
Kim, Taegong
Park, Cheong Hee
Tematy:
anomaly pattern detection
multiple binary-valued streams
outlier detection
outlier score
Pokaż więcej
Wydawca:
Społeczna Akademia Nauk w Łodzi. Polskie Towarzystwo Sieci Neuronowych
Powiązania:
https://bibliotekanauki.pl/articles/2147118.pdf  Link otwiera się w nowym oknie
Opis:
Anomaly pattern detection in a data stream aims to detect a time point where outliers begin to occur abnormally. Recently, a method for anomaly pattern detection has been proposed based on binary classification for outliers and statistical tests in the data stream of binary labels of normal or an outlier. It showed that an anomaly pattern can be detected accurately even when outlier detection performance is relatively low. However, since the anomaly pattern detection method is based on the binary classification for outliers, most well-known outlier detection methods, with the output of real-valued outlier scores, can not be used directly. In this paper, we propose an anomaly pattern detection method in a data stream using the transformation to multiple binary-valued data streams from real-valued outlier scores. By using three outlier detection methods, Isolation Forest(IF), Autoencoder-based outlier detection, and Local outlier factor(LOF), the proposed anomaly pattern detection method is tested using artificial and real data sets. The experimental results show that anomaly pattern detection using Isolation Forest gives the best performance.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of outlier detection methods in biomedical data
Autorzy:
Chromiński, K.
Tkacz, M.
Tematy:
wykrywanie próbek odstających
diagnozy medyczne
test obserwacji odstających
outlier detection
medical diagnoses
outlier test
Pokaż więcej
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Powiązania:
https://bibliotekanauki.pl/articles/333124.pdf  Link otwiera się w nowym oknie
Opis:
In this paper the use of outlier detection methods is discussed. This analysis is an introduction to the use of various methods of outlier detection in medical diagnoses (screening). The authors investigated the usefulness of selected outlier detection methods in the context of detection sensitivity, speed performance analysis and the difficulty of automating the performance analysis by using the test methods for outlier detection.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Unit root test in the presence of a single additive outlier small sample case
Autorzy:
Fellag, Hocine
Tematy:
autoregressive
outlier
power
size
unit root
Pokaż więcej
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Powiązania:
https://bibliotekanauki.pl/articles/729894.pdf  Link otwiera się w nowym oknie
Opis:
The one sided unit root test of a first-order autoregressive model in the presence of an additive outlier is considered. In this paper, we present a formula to compute the size and the power of the test when an AO (additive outlier) occurs at a time k. A small sample case is considered only.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Robust regression in monthly business survey
Autorzy:
Dehnel, Grażyna
Tematy:
robust regression
outlier detection
business statistics
Pokaż więcej
Wydawca:
Główny Urząd Statystyczny
Powiązania:
https://bibliotekanauki.pl/articles/466100.pdf  Link otwiera się w nowym oknie
Opis:
There are many sample surveys of populations that contain outliers (extreme values). This is especially true in business, agricultural, household and medicine surveys. Outliers can have a large distorting influence on classical statistical methods that are optimal under the assumption of normality or linearity. As a result, the presence of extreme observations may adversely affect estimation, especially when it is carried out at a low level of aggregation. To deal with this problem, several alternative techniques of estimation, less sensitive to outliers, have been proposed in the statistical literature. In this paper we attempt to apply and assess some robust regression methods (LTS, M-estimation, S-estimation, MM-estimation) in the business survey conducted within the framework of official statistics.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Detection of outlier observations in piezometric measurements: a case study in the Southern Region of Poland
Autorzy:
Lach, Stanisław
Tematy:
dam
outlier observations
safety
seepage
piezometer
Pokaż więcej
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Powiązania:
https://bibliotekanauki.pl/articles/2055775.pdf  Link otwiera się w nowym oknie
Opis:
One of the main modes of monitoring the geotechnical conditions of earth dams is piezometric measurement, which measures water levels in an open piezometer or water pressure in a closed piezometer. During piezometric measurements, various types of factors can cause disturbances in these measurements that take the form of systematic, accidental, or obvious mistakes. Before measurements from open or closed piezometers are analyzed, outliers due to coarse errors should be detected and rejected. Such observations may significantly influence the result of the analysis and cause erroneous assessment and interpretation of the phenomenon studied. To do this, statistical tests must be applied so that the doubtful measurement can be accepted or rejected at the assumed significance level. This paper uses five statistical tests for identifying and rejecting outliers: the Q-Dixon test, the Grubbs test, as well as the Hampel test, the Iglewicz and Hoaglin test, and the Rosner test. The aim of this article is to try to identify the most suitable test for periodic piezometric measurements. The scope of the study includes the analysis of piezometric measurements for the Czaniec Dam for the multi-year period 2017–2020.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Extreme gradient boosting method in the prediction of company bankruptcy
Autorzy:
Pawełek, Barbara
Tematy:
XGBoost
company bankruptcy
machine learning
outlier
Pokaż więcej
Wydawca:
Główny Urząd Statystyczny
Powiązania:
https://bibliotekanauki.pl/articles/1194455.pdf  Link otwiera się w nowym oknie
Opis:
Machine learning methods are increasingly being used to predict company bankruptcy. Comparative studies carried out on selected methods to determine their suitability for predicting company bankruptcy have demonstrated high levels of prediction accuracy for the extreme gradient boosting method in this area. This method is resistant to outliers and relieves the researcher from the burden of having to provide missing data. The aim of this study is to assess how the elimination of outliers from data sets affects the accuracy of the extreme gradient boosting method in predicting company bankruptcy. The added value of this study is demonstrated by the application of the extreme gradient boosting method in bankruptcy prediction based on data free from the outliers reported for companies which continue to operate as a going concern. The research was conducted using 64 financial ratios for the companies operating in the industrial processing sector in Poland. The research results indicate that it is possible to increase the detection rate for bankrupt companies by eliminating the outliers reported for companies which continue to operate as a going concern from data sets.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Unit root test in the presence of a single additive outlier small sample case
Autorzy:
Fellag, Hocine
Abdouche, Safia
Tematy:
autoregressive
outlier
power
size
unit root
Pokaż więcej
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Powiązania:
https://bibliotekanauki.pl/articles/729832.pdf  Link otwiera się w nowym oknie
Opis:
The one sided unit root test of a first-order autoregressive model in the presence of an additive outlier is considered. In this paper, we present a formula to compute the size and the power of the test when an AO (additive outlier) occurs at a time k. A small sample case is considered only.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Approximate bias for first-order autoregressive model with uniform innovations. Small sample case
Autorzy:
Nouali, Karima
Fellag, Hocine
Tematy:
autoregressive model
bias
outlier
uniform distribution
Pokaż więcej
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Powiązania:
https://bibliotekanauki.pl/articles/729836.pdf  Link otwiera się w nowym oknie
Opis:
The first-order autoregressive model with uniform innovations is considered. The approximate bias of the maximum likelihood estimator (MLE) of the parameter is obtained. Also, a formula for the approximate bias is given when a single outlier occurs at a specified time with a known amplitude. Simulation procedures confirm that our formulas are suitable. A small sample case is considered only.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Testing on the first-order autoregressive model with contaminated exponential white noise finite sample case
Autorzy:
Fellag, Hocine
Tematy:
autoregressive model
exponential distribution
outlier
test
Pokaż więcej
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Powiązania:
https://bibliotekanauki.pl/articles/729886.pdf  Link otwiera się w nowym oknie
Opis:
The testing problem on the first-order autoregressive parameter in finite sample case is considered. The innovations are distributed according to the exponential distribution. The aim of this paper is to study how much the size of this test changes when, at some time k, an innovation outlier contaminant occurs. We show that the test is rather sensitive to these changes.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some inferential questions in regard to analysing two-way Layouts and associated linear model theory and practice
Autorzy:
Clarke, Brenton
Monaco, Antony
Tematy:
outlier
two-way layout
adaptive estimation
heteroscedaticity
Pokaż więcej
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Powiązania:
https://bibliotekanauki.pl/articles/729772.pdf  Link otwiera się w nowym oknie
Opis:
In analysing a well known data set from the literature which can be thought of as a two-way layout it transpires that a robust adaptive regression approach for identifying outliers fails to be sensitive enough to detect the possible interchange of two observations. On the other hand if one takes the classical approach of diagnostic checking one may also stop too early and be satisfied with a model that falls short of a more detailed analysis that takes account of heteroscedasticity in the data. An exact F-test for heteroscedasticity in the two way layout is compared with various more general tests proposed by Shukla. In conclusion it is noted that when modelling the particular form of heteroscedasticity countenanced here, the estimated column effects are unchanged from those estimated from the model assuming homogeneous error variance structure. It is only the estimated variances of these column effects that changes.
Dostawca treści:
Biblioteka Nauki
Artykuł

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies