Informacja

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

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "real data" wg kryterium: Temat

  Lista filtrów
Wyrównaj
Wyświetlanie 1-15 z 53
Tytuł:
Analysis of real underkeel clearance for Świnoujście–Szczecin waterway in years 2009-2011
Autorzy:
Schoeneich, M.
Sokołowska, S.
Powiązania:
https://bibliotekanauki.pl/articles/360553.pdf
Data publikacji:
2012
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
real data
probabilistic model
underkeel clearance
Opis:
The paper presents the practical using of model for underkeel clearance evaluation. Real data from Maritime Office concerning ships which enter ports was used to analysis of results first probabilistic model of underkeel clearance and next integrated system. During analysis mean probability that underkeel clearance will be less than zero was determined for ports in Świnoujście, Szczecin and Police. Results of this analysis can be used for further research connected with integrated system for underkeel clearance calculation.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2012, 32 (104) z. 2; 162-166
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the ships’ UKC by probabilistic model based on chosen real data in period 2005 till 2009
Autorzy:
Schoeneich, M.
Powiązania:
https://bibliotekanauki.pl/articles/2069658.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
under-keel clearance
UKC
probabilistic model
real data
Opis:
The paper is concerned with the analysis of under-keel clearance of ships based on real data from Szczecin Maritime Office. Using probabilistic method for UKC assessment give it possibility to create the distribution of under-keel clearance in several ship’s passages and in further step to determine the probability of ship’s grounding accident during the port approach. The results of using this type of model could be used in risk assessment of ships entering to the ports, therefore it is possible to used probabilistic model in Maritime Office employees’ everyday decision making practice. Research results present verification of probabilistic model, based on data from Vessel Traffic Service database and probability of touching the bottom during ships’ passages on Swinoujscie - Szczecin waterway. Moreover there are presented examples of these situations when entering to the port for analysed ships is not allowed according to the model.
Źródło:
Journal of Polish Safety and Reliability Association; 2010, 1, 1; 215--220
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Workstation for training ASW helicopter navigators and analysing real flight data
Autorzy:
Raganowicz, A.
Kilian, L.
Marszal, J.
Schmidt, A.
Sidorko, T.
Rudnicki, M.
Powiązania:
https://bibliotekanauki.pl/articles/332784.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
helicopter navigators
real flight data
aviation
Opis:
The article presents a training and diagnostic workstation designed for Polish Navy ASW helicopter navigators. Installed at the helicopter base, the workstation is used for training and instruction in operating the device and analysing information gathered by navigators during the flight using the ASW onboard sonar, sonobuoy receiver and magnetometer. The workstation allows instructors to task two operators and monitor their performance under conditions resembling those onboard a plane. The tasks involve the operation of the consoles and collecting information during tactical situations, diagnosing damage and analysing flight data in office environment. The objective is to ensure proper helicopter navigator training and experience given the limited possibility of training flights.
Źródło:
Hydroacoustics; 2009, 12; 181-188
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Real world data supporting identification of the pharmacist’s role in obesity and overweight treatment in Poland – a preliminary report
Autorzy:
Drozd, Mariola
Bułaś, Lucyna
Szkultecka-Dębek, Monika
Skowron, Agnieszka
Powiązania:
https://bibliotekanauki.pl/articles/454892.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Rzeszowski. Wydawnictwo Uniwersytetu Rzeszowskiego
Tematy:
overweight
obesity
pharmaceutical care
treatment, real world data
Opis:
Introduction. Obesity is a significant health and economic problem, both for the patient and the health care system. An essential element in the prevention and treatment of each disease is the engagement of all groups of healthcare professionals. In our study, we performed an analysis of the real world data, obtained from a survey of the medical and socioeconomic problems associated with overweight and obesity. We aimed to identify the pharmacist’s role in the management of overweight and obese patients, including their individualized education in an outpatient setting. Material and methods. The study material consisted of responses obtained from a specially designed questionnaire. Our findings indicate that the study patients had easy access to a pharmacist’s professional knowledge, relevant to comprehensive treatment of obesity. In addition, our data indicates a lack of patient knowledge of a healthy lifestyle and an inability to implement such knowledge in practice. Results. The community pharmacist should actively provide support to patients with obesity (including the primary obesity and those who want to lose excessive body mass for health-related and also for aesthetic reasons) and the management of their weight. The results of our study should be considered as an introduction to further research to facilitate the understanding of problems and expectations of patients and to prepare pharmacists to perform pharmaceutical care (PC) in this regard. Conclusion. One of the potential options to protect society against the obesity epidemic is an education about the risks inherent to obesity and promotion of a healthy lifestyle.
Źródło:
European Journal of Clinical and Experimental Medicine; 2017, 3; 192-199
2544-2406
2544-1361
Pojawia się w:
European Journal of Clinical and Experimental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Properties of the transmission-disequilibrium test for the detection of quantitative trait loci in livestock
Autorzy:
Szyda, J
Liu, Z.
Wild, V.
Powiązania:
https://bibliotekanauki.pl/articles/2044224.pdf
Data publikacji:
1998
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
transmission-disequilibrium test
German Holstein cattle
chromosome localization
milk production
power
simulated data
population
real data
detection
dairy cattle
simulation system
Opis:
The transmission-disequilibrium test (TDT) is a model-free method to detect linkage between a marker and a trait locus. Originally developed to map disease genes in human genetics, this statistic has been recently extended to deal with quantitative characters. The emphasis of current research is on investigating statistical properties of the test applied to data from livestock populations. For various constellations of sample parameters, it is shown via simulation that the empirically derived null hypothesis distribution of TDT remains in good agreement with its asymptotic distribution while its power is satisfactory only for very close linkage. TDT is then applied to a real data set from milk production data of a dairy cattle population.
Źródło:
Journal of Applied Genetics; 1998, 39, 4; 309-319
1234-1983
Pojawia się w:
Journal of Applied Genetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Znaczenie rewizji danych w procesie modelowania
Autorzy:
Ziembińska, Paulina
Powiązania:
https://bibliotekanauki.pl/articles/543640.pdf
Data publikacji:
2017
Wydawca:
Główny Urząd Statystyczny
Tematy:
data revisions
real-time data
national accounts
rewizje danych
dane w czasie rzeczywistym
rachunki
narodowe
Opis:
Artykuł ma na celu przedstawienie i wstępną analizę nowego — skonstruowanego na podstawie biuletynów statystycznych GUS — zbioru danych w czasie rzeczywistym (real-time data) dla polskiej gospodarki, obejmującego zmienne makroekonomiczne. Zbiór ten umożliwia odpowiedzi na pytania dotyczące procesu rewizji, który wpływa nie tylko na spójność danych, ale także na statystyczne własności modeli ekonometrycznych i oparte na nich wnioskowanie. W szczególności omówiono i wyodrębniono rewizje metodologiczne, co umożliwia ich analizę statystyczną oraz weryfikację przyczyn nieoczekiwanych rewizji niemetodologicznych. Badanie wskazuje, że dla istotnej grupy zmiennych rewizje są systematyczne. Wynikają one z redukcji błędu pomiaru, nie zaś napływu nowych informacji, co ma znaczące konsekwencje dla modelowania.
This study aims to present the new real-time set of macroeconomic data for the Polish economy constructed on the basis of the monthly Statistical Bulletins published by the Central Statistical Office. This dataset gives answers to many important questions on the revision processes which have an influence on the consistency of data as well as effects on attributes of econometric models and statistical inference. In particular, in this article methodological revisions were discussed and their types were specified. It is a base for the statistical analysis and verification of reasons of unexpected non-methodological revisions. The research indicates that in the significant group of variables revisions are systematic. This is a result of the error measurement reduction, not the accessibility of new information which has significant implications for modeling.
Źródło:
Wiadomości Statystyczne. The Polish Statistician; 2017, 2; 5-30
0043-518X
Pojawia się w:
Wiadomości Statystyczne. The Polish Statistician
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
End-of-sample vs. Real-time Data: Perspectives for Analysis of Expectations
Autorzy:
Tomczyk, Emilia
Powiązania:
https://bibliotekanauki.pl/articles/500478.pdf
Data publikacji:
2013-09-01
Wydawca:
Szkoła Główna Handlowa w Warszawie
Tematy:
end-of-sample (EOS) data
real-time (RTV) data
data revisions
economic databases
expectations
Opis:
Data revision is usually defined as an adjustment published after initial value had been announced; it may reflect rectification of errors, availability of new information, introduction of new measurement or aggregation techniques etc. This paper addresses the impact of data revisions on measures of expectations and offers an introduction to empirical analysis of data vintage in testing properties of expectations. It also defines and classifies data revisions and presents a review of literature and databases available for the purposes of real time analysis.
Źródło:
Prace i Materiały Instytutu Rozwoju Gospodarczego SGH; 2013, 93: Expectations and Forecasting; 45-69
0866-9503
Pojawia się w:
Prace i Materiały Instytutu Rozwoju Gospodarczego SGH
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Significance of real-time petro-physical data for an optimal remote geosteering operation in complex geological reservoirs
Autorzy:
Amer, Muhammad Attique
Ehsan, Muhsan
Akhtar, Muhammad Javid
Powiązania:
https://bibliotekanauki.pl/articles/2055849.pdf
Data publikacji:
2021
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
remote geosteering
integrated real-time data
logging while drilling
collaborative decision making
reservoir management
Opis:
In the last decade, the oil industry has transitioned from primarily drilling vertical wells to a majority of extended reach complex horizontal wells with help of geosteering techniques for better reservoir and production efficiencies. The overall objective of geosteering and well placement has helped to maximize reservoir contact by the keeping well trajectory in the pay zone with the help of quality real-time data, especially in these uncertain times of pandemic due to COVID-19. This paper illustrates the immense impact of real-time data feeds (special logging tools/images) at operation centers with the full remote expert support of multidisciplinary teams. The proper data communication mechanism is also helpful to share the information across asset teams in a timely manner to drill complex wells remotely. To achieve the desired geosteering objectives, experts monitor and evaluate the real-time data in a landing well accurately in the pay horizon by designing the well path which considers geological variables like (reservoir architecture, permeability and porosity distribution, and fluid contacts) which further helps update the reservoir models in real-time based on the latest subsurface information for better reservoir management and timely decision making.
Źródło:
Geology, Geophysics and Environment; 2021, 47, 3; 125--130
2299-8004
2353-0790
Pojawia się w:
Geology, Geophysics and Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Streaming Real-time Data in Distributed Dispatcher and Teleinformation Systems for Visualization of Multimedia Data of the Border Guard
Autorzy:
Blok, M.
Czaplewski, B.
Kaczmarek, S.
Litka, J.
Narloch, M.
Sac, M.
Powiązania:
https://bibliotekanauki.pl/articles/116615.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
border guard
transport telematics
events visualization post
distributed dispatcher
multimedia data
real-time data
teleinformation systems
visualization
Opis:
Surveillance of the sea borders is a very important task for the Border Guard. Monitoring of country maritime border is an important task of the Border Guard. This task can be facilitated with the use of the technology enabling gathering information from distributed sources and its supervision and visualization. This task can be accomplished using a technology that allows to collect information from distributed sensors of different types, unify the collected information, and present the synchronized data. The system presented in the paper is an extension and enhancement of the previously developed distributed map data exchange system. The added functionality allows to supplement the map data with multimedia (telephone and radio calls, video (cameras), photos, files, SMS/SDS) and presentation of current and archival situation on a multi-display screen in the Events Visualization Post. In the paper, the system architecture, functionality and main system elements are described and supported with preliminary analysis and test results.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2018, 12, 2; 217-229
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The lagged effect of air pollution on human eosinophils: a distributed lag non-linear model
Autorzy:
Ding, Zhaojun
Xie, Zhen
Su, Yang
Qi, Jiying
Cui, Bin
Powiązania:
https://bibliotekanauki.pl/articles/2116610.pdf
Data publikacji:
2020-04-30
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
air pollution
gender difference
eosinophils
real-world data
lagged effect
distributed lag non-linear model
Opis:
ObjectivesThe aim of this study was to determine the lag between exposure to air pollutants and changes in human eosinophil counts.Material and MethodsThis was a retrospective study employing 246 425 physical examination records dated December 2013 – December 2016 from Chengdu, China. The authors determined the prevalence of individuals with eosinophil counts above the normal reference range each day. A distributed lag non-linear model was used to evaluate the lagged effect of each air pollutant on eosinophil counts. The lagged effects of each air pollutant were counted and presented with smoothing splines.ResultsThe effects of air pollutants such as particulate matter (PM2.5, aerodynamic diameters <2.5 μm; PM10, aerodynamic diameters <10 μm), nitrogen dioxide (NO2) and ozone (O3) were evaluated. In women, the effects of PM2.5 (RR = 1.154, 95% CI: 1.061–1.255) and PM10 (RR = 1.309, 95% CI: 1.130–1.517) reached the maximum values on lag day 0. In men, there was no significant effect of PM2.5, but significant effects of PM10 were found for lag days 20–28. The effects of NO2 and O3 on eosinophils were not statistically significant for either gender.ConclusionsThe air pollutants of PM10 have a significant effect on human eosinophils for both women and men, but with different temporal patterns, with women showing a lag of 0–5 days and men showing a lag of 20–28 days. In addition, PM2.5 was significant for women with a lag of 0–3 days but it was not significant for men.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2020, 33, 3; 299-310
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
DATA VINTAGE IN TESTING PROPERTIES OF EXPECTATIONS
Autorzy:
Tomczyk, Emilia
Powiązania:
https://bibliotekanauki.pl/articles/453446.pdf
Data publikacji:
2015
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Katedra Ekonometrii i Statystyki
Tematy:
end-of-sample (EoS) data
real time (RTV) data
data revisions
quantification procedures
expectations
unbiasedness
orthogonality
Opis:
Results of quantification procedures and properties of expectations series obtained for two data vintages are described. Volume index of production sold in manufacturing is defined for end-of-sample and real time data, and evaluated against expectations expressed in business tendency surveys. Empirical analysis confirms that while there are only minor differences in quantification results with respect to data vintage, properties of expectations time series obtained on their basis do diverge.
Źródło:
Metody Ilościowe w Badaniach Ekonomicznych; 2015, 16, 2; 123-132
2082-792X
Pojawia się w:
Metody Ilościowe w Badaniach Ekonomicznych
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The importance of data revisions for statistical inference
Znaczenie rewizji danych dla wnioskowania statystycznego
Autorzy:
Ziembińska, Paulina
Powiązania:
https://bibliotekanauki.pl/articles/985676.pdf
Data publikacji:
2021
Wydawca:
Główny Urząd Statystyczny
Tematy:
data revisions
real-time data
time series analysis
forecasting
rewizje danych
dane w czasie rzeczywistym
analiza szeregów czasowych
prognozowanie
Opis:
The aim of the study is a quantitative analysis of revisions conducted by means of a new, real-time macroeconomic dataset for Poland, designed on the basis of the Statistical bulletin (Biuletyn statystyczny) published by Statistics Poland, covering the period from as early as 1995 until 2017. Polish data have positively verified a number of hypotheses concerning the impact of data revisions on the modelling process. Procedures assessing the properties of time series can yield widely discrepant results, depending on the extent to which the applied data have been revised. A comparison of the fitted ARIMA models for series of initial and final data demonstrates that the fitted models are similar for the majority of variables. In the cases where the form of the model is identical for both series, the coefficients retain their scale and sign. Most differences between coefficients result from a different structure of the fitted model, which causes differ-ences in the autoregressive structure and can have a considerable impact on the ex ante infer-ence. A prognostic experiment confirmed these observations. For a large number of variables, the total impact of revisions on the forecasting process exceeds 10%. Extreme cases, where the impact goes beyond 100%, or situations where data have a direct impact on the forecast sign, are also relatively frequent. Taking these results into account by forecasters could significantly improve the quality of their predictions. The forecast horizon has a minor impact on these conclusions. The article is a continuation of the author's work from 2017.
Celem pracy jest ilościowa analiza rewizji danych makroekonomicznych w czasie rzeczywistym dla Polski pochodzących z nowego zbioru utworzonego na podstawie „Biuletynu statystycznego” GUS i obejmującego okres od 1995 do 2017 r. Polskie dane pozytywnie weryfikują wiele hipotez dotyczących wpływu rewizji danych na proces modelowania. Procedury oceniające własności szeregów czasowych mogą dawać istotnie różne wyniki w zależności od tego, jak bardzo rewidowane dane zostaną użyte. Porównanie dopasowanych modeli ARIMA dla szeregów pierwszych i finalnych odczytów wskazuje, że w przypadku większości zmiennych dopasowane modele są podobne. Gdy postać modelu jest taka sama dla obu szeregów, współczynniki zachowują skalę i znak. Większość różnic we współczynnikach wynika z odmiennej struktury dopasowanego modelu, co wpływa na różnice w strukturze autoregresyjnej i może mieć niemały wpływ na wnioskowanie ex ante. Potwierdza to eksperyment prognostyczny. Dla dużej części zmiennych całkowity wpływ rewizji na proces prognozowania wynosi powyżej 10%. Nie są też wyjątkiem ekstremalne przypadki, w których ten wpływ przekracza 100%, czy sytuacje, w których dane bezpośrednio wpływają na znak prognozy. Uwzględnienie tych wyników przez prognostów mogłoby znacząco poprawić jakość predykcji. Horyzont prognozy ma niewielki wpływ na te konkluzje. Artykuł jest kontynuacją pracy autorki z 2017 r.
Źródło:
Wiadomości Statystyczne. The Polish Statistician; 2021, 66, 2; 7-24
0043-518X
Pojawia się w:
Wiadomości Statystyczne. The Polish Statistician
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quantification of expectations for general economic situation on the basis of industrial production index with data revisions
Autorzy:
Tomczyk, Emilia
Powiązania:
https://bibliotekanauki.pl/articles/500423.pdf
Data publikacji:
2015
Wydawca:
Szkoła Główna Handlowa w Warszawie
Tematy:
end-of-sample (EOS) data
real time (RTV) data
data revisions
survey data
general economic situation
expectations
quantification
regression method
Opis:
Use of appropriate data vintages and taking data revisions into account have only recently became a staple of applied econometric analysis. In this paper, the topic of data vintage in regression quantification procedures is readdressed for survey data on general economic situation. From empirical analysis it follows that quantification of survey data on general economic situation on the basis of industrial production index does not present a significant improvement over the use of response balance. Additionally, results obtained for real-time and end-of-sample data are very similar and do not suggest superiority of any of these two data vintages as far as quantification of survey data on general economic situation is concerned
Źródło:
Prace i Materiały Instytutu Rozwoju Gospodarczego SGH; 2015, 97: Economic cycles and uncertainty; 95-106
0866-9503
Pojawia się w:
Prace i Materiały Instytutu Rozwoju Gospodarczego SGH
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
My City Dashboard: Real-time Data Processing Platform for Smart Cities
Autorzy:
Usurelu, C.-C.
Pop, C.
Powiązania:
https://bibliotekanauki.pl/articles/307785.pdf
Data publikacji:
2017
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
big data
data analytics
real-time processing
smart cities
statistics
Opis:
In recent years, with the increasing popularity of IoT, the rapid growth of smartphone usage enabled by the increase adoption of Internet services and the continuously decreasing costs of these devices and services has led to a huge increase in the volume of data that governments can use in the context of smart city initiatives. The need for analytics is becoming a requirement for smart city projects such as city dashboards to provide citizens with an easy to understand overview of the city. As such, data should be analyzed, reduced and presented in such a way that citizens can easily understand various aspects of the city and use this information to increase quality of life. In this paper, we firstly present the context and the start of the design and implementation of proposed solution for real-time data processing in smart cities, mainly an analytics processing pipeline and a dashboard prototype for this solution, named My City Dashboard. We focus on high scalability and modularity of this platform.
Źródło:
Journal of Telecommunications and Information Technology; 2017, 1; 89-100
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
VERYFICATION OF LOCATION PROBLEM IN ECONOMIC RESEARCH
Autorzy:
Kozioł - Kaczorek, Dorota
Parlińska, Maria
Powiązania:
https://bibliotekanauki.pl/articles/655862.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
location problem
data analysis
real-estate market
Opis:
In economic research very often the location problem in the single sample or estimation  of the difference in two samples location is commonly tested by experimental economists. Usually the used tests are Wilcoxon test for single sample location or Wilcoxon – Mann – Whitney for two samples location problem. Unfortunately those tests have some disadvantages such as robustness against assumptions or week efficiency. In the paper, some less known procedures, which allow avoid those problems, will be presented. Considered methods will be illustrated on the example of the data  analysis from real-estate market.
Źródło:
Acta Universitatis Lodziensis. Folia Oeconomica; 2014, 3, 302
0208-6018
2353-7663
Pojawia się w:
Acta Universitatis Lodziensis. Folia Oeconomica
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 53

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