Wyniki wyszukiwania - Biblioteka Nauki

1

Statistical pathways - a method of visualization statistical rules

100%

Salapa K. , Stanisz A.

Bio-Algorithms and Med-Systems

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2009

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tom Vol. 5, no. 9

127--131

EN

The aim of this article is the application of flow charts in teaching statistics. It contains three exemplary diagrams concerning the most common tests such as independent one-sample, two-sample t-test and one-way analysis of variance. They present particular steps in process of selection the most relevant test. Hypothesis testing is a powerful tool in science because of the potential to explain causality. Unfortunately students have difficulties in recognition the correct test. Such diagrams could facilitate the understanding and studying statistical rules. All flowcharts presented in this paper have been prepared using the authoring tool called BIT Pathways.

2

Speaker identification based on artificial neural networks. Case study: the Polish vowel (pilot study)

80%

Salapa K. , Trawińska A. , Roterman I. , Tadeusiewicz R.

Bio-Algorithms and Med-Systems

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2014

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tom Vol. 10, no. 2

91--99

EN

Current statistical methods and technologies used for speaker identification via dynamic formant frequency often involve classic multivariate analyses that must meet a number of criteria in order to be considered trustworthy. The authors propose more advanced classification techniques, including artificial neural networks. Owing to iterative learning algorithms, neural networks can be trained to detect highly complex, nonlinear relations hidden in input data. This study specifically considers feed-forward multilayer perceptron and radial basic function network models. The investigation involves an analysis of the Polish vowel (stressed or unstressed) in selected contexts described by the four lowest formant frequencies. Results indicate high accuracy of neural networks as a speaker identification tool reaching up to 100%. In addition, the authors have determined that the accuracy of classification is similar when based on a single context to when input data are aggregated over several different contexts.

3

Stężenie hs-cTnT a ryzyko wystąpienia niepożądanych zdarzeń sercowo-naczyniowych u pacjentów izby przyjęć z wykluczonym ostrym zespołem wieńcowym

61%

Anders M. , Trabka-Zawicki A. , Guzik B. , Salapa K. , Durda K. , Zmudka K. , Sztefko K.

Diagnostyka Laboratoryjna

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2013

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tom 49

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nr 3

4

Sex determination based on the analysis of a contemporary Polish population’s palatine bones: a computed tomography study of 1,200 patients

51%

Tomaszewska I. M. , Fraczek P. , Gomulska M. , Pliczko M. , Sliwinska A. , Salapa K. , Chrzan R. , Kowalski P. , Nowakowski M. , Walocha J. A.

Folia Morphologica

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2014

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tom 73

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nr 4

EN

Background: The aims of the present study were to assess whether the hard palate reveals any measurable sex-related differences, and to create a mathematical model which would differentiate between males and females using hard palate measurements alone. Materials and methods: The present study was conducted on 1,200 archived sinus computed tomography (CT) scans. Each cranial measurement was taken twice by the same observer, and in cases of any discrepancies, the mean of the two values was recorded. Twenty per cent of randomly chosen samples were re-measured by an observer who did not partake in assessing the samples the first time. Logistic regression was used to derivate two mathematical formulas which would calculate the probability of a skull being male. Results: The studied group comprised 1,200 head CT’s (627 female; 52.3%). The mean age of the group was 43.5 ± 17.4 years — no age difference between sexes was noted (p = 0.37). All of the performed measurements were significantly (p < 0.0001) larger in males than in females. The mathematical formula based on the “orale-spina nasalis posterior” (O-SNP) distance alone had a reliability rate of 68.35%. The equation based on the depth of the right greater palatine canal (GPC), the O-SNP distance and the anterior width of the palatal arch (AWPA) had a reliability rate of 78.37%. Conclusions: The most prominent sexually dimorphic parameters were the O-SNP, the GPC depth and the AWPA. The mathematical models presented in the current study can be used to successfully distinguish between sexes during forensic examination. (Folia Morphol 2014; 73, 4: 462–468)

5

Ab initio protein structure prediction – the hydrophobicity distribution analysis

41%

Evangelista G. , Minervini G. , Polticelli F. , Malawski M. , Szepieniec T. , Flis Ł. , Prymula K. , Kochańczyk M. , Matczyńska E. , Wiśniowski Z. , Salapa K. , Banach M. , Roterman I.

Bio-Algorithms and Med-Systems

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2011

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tom Vol. 7, no. 2

5--12

EN

The three-dimensional structures generated for 20 “never born proteins” (NBP – random amino acid sequence with no significant homology to existing proteins) using two different techniques: ROSETTA (called R in the paper) and “fuzzy oil drop” model (called S in the paper) were compared to estimate the accordance with the assumed model estimating the influence of an external force field on the final structure of the protein. Selected structures are those corresponding to the highest (10 proteins) and lowest (10 proteins) RMS-D values obtained measuring the similarity between the R and S structures. The R structures generated according to an internal force field (the individual inter-molecular interaction) including solvation effects were analyzed using the “fuzzy oil drop” model as target model. The second applied model “fuzzy oil drop” generated structures characterized by an ordered hydrophobic core structure. 13 of the 20 selected S structures appeared to be accordant with the “fuzzy oil drop” model while 6 out of the 20 structures appeared to be accordant with external force field for R structures which suggests a general interpretation of the influence of an external force field on the folding simulation.