8,713 research outputs found
A robust procedure for comparing multiple means under heteroscedasticity in unbalanced designs.
Investigating differences between means of more than two groups or experimental conditions is a routine research question addressed in biology. In order to assess differences statistically, multiple comparison procedures are applied. The most prominent procedures of this type, the Dunnett and Tukey-Kramer test, control the probability of reporting at least one false positive result when the data are normally distributed and when the sample sizes and variances do not differ between groups. All three assumptions are non-realistic in biological research and any violation leads to an increased number of reported false positive results. Based on a general statistical framework for simultaneous inference and robust covariance estimators we propose a new statistical multiple comparison procedure for assessing multiple means. In contrast to the Dunnett or Tukey-Kramer tests, no assumptions regarding the distribution, sample sizes or variance homogeneity are necessary. The performance of the new procedure is assessed by means of its familywise error rate and power under different distributions. The practical merits are demonstrated by a reanalysis of fatty acid phenotypes of the bacterium Bacillus simplex from the "Evolution Canyons" I and II in Israel. The simulation results show that even under severely varying variances, the procedure controls the number of false positive findings very well. Thus, the here presented procedure works well under biologically realistic scenarios of unbalanced group sizes, non-normality and heteroscedasticity
Carbon Trading with Blockchain
Blockchain has the potential to accelerate the deployment of emissions
trading systems (ETS) worldwide and improve upon the efficiency of existing
systems. In this paper, we present a model for a permissioned blockchain
implementation based on the successful European Union (EU) ETS and discuss its
potential advantages over existing technology. We propose an ETS model that is
both backwards compatible and future-proof, characterised by
interconnectedness, transparency, tamper-resistance and high liquidity.
Further, we identify key challenges to implementation of a blockchain ETS, as
well as areas of future work required to enable a fully-decentralised
blockchain ETS
9-Ethyl-10-methylacridinium trifluoromethanesulfonate
In the molecule of the title compound, C16H16N+·CF3SO3
−, the central ring adopts a flattened-boat conformation, and the two aromatic rings are oriented at a dihedral angle of 3.94 (2)°. In the crystal structure, weak intermolecular hydrogen bonds link the molecules. There are π–π contacts between the aromatic rings and the central ring and one of the aromatic rings [centroid–centroid distances = 3.874 (2), 3.945 (2) and 3.814 (2) Å]. There is also an S—O⋯π contact between the central ring and one of the O atoms of the anion
CLEARER: a new tool for the analysis of X-ray fibre diffraction patterns and diffraction simulation from atomic structural models
Fibre diffraction can provide structural information about polymers and biopolymers that is unobtainable using other methods. This method has been used to elucidate the structures of many polymers, biopolymers and protein assemblies. Extracting structural information from fibre diffraction patterns is a major challenge. A computer program called CLEARER has been developed that aids the detailed analysis of polycrystalline fibre diffraction patterns. It offers an easy-to-use interface that enables diffraction data processing, analysis and simulation of diffraction patterns. It is likely to be applicable to structural determination for a wide range of polymeric fibrous materials. CLEARER simplifies and speeds up the data analysis process and helps to utilize all of the structural information present in the analysed X-ray and electron diffraction patterns
Probleme von Änderungen während des Funktionierens-von Einrichtungen - aus der Sicht von Untersuchungen
Zadanie pt. „Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki” nr 885/P-DUN/2014 zostało dofinansowane ze środków MNiSW w ramach działalności upowszechniającej naukę
Nauczanie języka polskiego w landzie Szlezwik-Holsztyn (Niemcy)
Zadanie pt. „Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki” nr 885/P-DUN/2014 zostało dofinansowane ze środków MNiSW w ramach działalności upowszechniającej nauk
Założenia metodyczno-programowe kursu języka polskiego dla cudzoziemców- ekonomistów
Zadanie pt. Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki nr 885/P-DUN/2014 zostało dofinansowane ze środków MNiSW w ramach działalności upowszechniającej naukę
The market of one percent in small towns in Poland in 2016
The article presents the genesis, legal conditions and characteristics of functioning of the public benefit organization (OPP) in Poland, which are beneficiaries of the one per cent mechanism. In the main part, the focus was on the spatial relativity of funds from 1% to OPPs located in Poland, with particular focus on those organizations that were established in small towns in 2016. In addition, it was compared how the relocation of funds was from 1% depending on the size (type) of the town and the statutory objectives of OPP. This allowed us to define the characteristics of OPPs operating in small towns.Artykuł przedstawia genezę, uwarunkowania prawne i charakterystykę funkcjonowania organizacji pożytku publicznego (OPP) w Polsce, które są beneficjentami tzw. mechanizmu jednego procentu. W części zasadniczej skupiono się na analizie przestrzennej relokacji środków z 1% do OPP zlokalizowanych w Polsce, ze szczególnym uwzględnieniem tych organizacji, które swoją siedzibę miały w małych miastach w 2016 roku. Dodatkowo, porównano jak wyglądała relokacja środków z 1% w zależności od wielkości (typu) miejscowości i celów statutowych OPP. Pozwoliło to określić cechy charakterystyczne OPP funkcjonujących w małych miastach
On the Reverse Engineering of the Citadel Botnet
Citadel is an advanced information-stealing malware which targets financial
information. This malware poses a real threat against the confidentiality and
integrity of personal and business data. A joint operation was recently
conducted by the FBI and the Microsoft Digital Crimes Unit in order to take
down Citadel command-and-control servers. The operation caused some disruption
in the botnet but has not stopped it completely. Due to the complex structure
and advanced anti-reverse engineering techniques, the Citadel malware analysis
process is both challenging and time-consuming. This allows cyber criminals to
carry on with their attacks while the analysis is still in progress. In this
paper, we present the results of the Citadel reverse engineering and provide
additional insight into the functionality, inner workings, and open source
components of the malware. In order to accelerate the reverse engineering
process, we propose a clone-based analysis methodology. Citadel is an offspring
of a previously analyzed malware called Zeus; thus, using the former as a
reference, we can measure and quantify the similarities and differences of the
new variant. Two types of code analysis techniques are provided in the
methodology, namely assembly to source code matching and binary clone
detection. The methodology can help reduce the number of functions requiring
manual analysis. The analysis results prove that the approach is promising in
Citadel malware analysis. Furthermore, the same approach is applicable to
similar malware analysis scenarios.Comment: 10 pages, 17 figures. This is an updated / edited version of a paper
appeared in FPS 201
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