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Found 6319 publications

Are collision and crossing course surrogate safety indicators transferable? A probability based approach using extreme value theory

Haneen Farah Marjan Hagenzieker Aliaksei Laureshyn Attila Borsos

Publication Name: Accident Analysis and Prevention

Publication Date: 2020-08-01

Volume: 143

Issue: Unknown

Page Range: Unknown

Description:

In order to overcome the shortcomings of crash data a number of surrogate measures of safety have been developed and proposed by various researchers. One of the most widely used temporal indicators is time-to-collision (TTC) which requires the road users to be on a collision course. Road users that are strictly speaking not on a collision course actually might behave and take evasive actions as if they were, thus indicating that such near-miss situations might also be relevant for safety analysis. Taking that into account, a more flexible indicator T2, which does not require the two vehicles to be on a collision course, describes the expected time for the second road user to arrive at the conflict point. Recently extreme value theory (EVT) offering two approaches, block maxima (BM) and Peak over Threshold (POT), has been applied in combination with surrogate indicators to estimate crash probabilities. Most of this research has focused on testing BM and POT as well as validating various surrogate safety indicators by comparing model estimates to actual crash frequencies. The comparison of collision course indicators with indicators including crossing course interactions and their performance using EVT has not been investigated yet. In this study we are seeking answers to under what conditions these indicators perform better and whether they are transferable. Using data gathered at a signalized intersection focusing on left-turning and straight moving vehicle interactions our analysis concluded that the two indicators are transferable with stricter threshold values for T2 and that POT gives more reasonable results.

Open Access: Yes

DOI: 10.1016/j.aap.2020.105517

Design of lqr controller for gan based buck converter

Miklós Kuczmann Miklos CSIZMADIA

Publication Name: Pollack Periodica

Publication Date: 2020-08-01

Volume: 15

Issue: 2

Page Range: 37-48

Description:

This paper presents a design procedure of a switched-mode power converter, the well-known synchronous buck converter: The calculating method, and how to choose the parts of the converter are presented in detail, like the inductor, the capacitor and the semiconductors as well as the design of the state feedback. During the design process the efficiency and the high switching frequency are very important: The switching semiconductors are Gallium Nitride based. Then, a linear-quadratic regulator is designed and applied to the particular case of a buck converter.

Open Access: Yes

DOI: 10.1556/606.2020.15.2.4

Testing output variables for sensitivity study of nonlinear vibration systems

F. Hajdu G. Y. Molnarka

Publication Name: Pollack Periodica

Publication Date: 2020-08-01

Volume: 15

Issue: 2

Page Range: 70-81

Description:

In this study the detailed One-at-a-Time sensitivity analysis of nonlinear massspring- damper systems is carried out with numerical simulation. The degree of sensitivity was measured with a sensitivity index and based on its sensitivity Fuzzy-sets were established. The sensitivity of a parameter then can be expressed by the membership to the Fuzzy-sets. In this study the root mean square of acceleration, the maximum amplitude of acceleration and the peak frequency were chosen as output variables to measure sensitivity. With this research it was proven, that the root mean square of acceleration and the peak frequency can be used for sensitivity study of nonlinear vibration systems effectively.

Open Access: Yes

DOI: 10.1556/606.2020.15.2.7

Ultrasonic sensor fusion inverse algorithm for visually impaired aiding applications

György Kovács Szilvia Nagy

Publication Name: Sensors Switzerland

Publication Date: 2020-07-01

Volume: 20

Issue: 13

Page Range: 1-16

Description:

Depth mapping can be carried out by ultrasound measuring devices using the time of flight method. Ultrasound measurements are favorable in such environments, where the light or radio frequency measurements can not be applied due to the noise level, calculation complexity, reaction time, size and price of the device, accuracy or electromagnetic compatibility. It is also usual to apply and fusion ultrasound sensors with other types of sensors to increase the precision and reliability. In the case of visually impaired people, an echolocation based aid for determining the distance and the direction of obstacles in the surroundings can improve the life quality by giving the possibility to move alone and individually in unlearnt or rapidly changing environments. In the following considerations, a model system is presented which can provide rather reliable position and distance to multiple objects. The mathematical model based on the time of flight method with a correction: it uses the measured analog sensor signals, which represent the probability of the presence of an obstacle. The device consists of multiple receivers, but only one source. The sensor fusion algorithm for this setup and the results of indoor experiments are presented. The mathematical model allows the usage, processing, and fusion of the signals of up to an infinite number of sensors. In addition, the positions of the sensors can be arbitrary, and the mathematical model does not restrict them to be placed in regular formations.

Open Access: Yes

DOI: 10.3390/s20133682

Bacteriological quality of raw ovine milk from different sheep farms

Ferenc Peles Andualem Tonamo Levente Czeglédi István Komlósi László Varga

Publication Name: Animals

Publication Date: 2020-07-01

Volume: 10

Issue: 7

Page Range: 1-9

Description:

The primary purpose of this research was to examine the bacteriological properties of raw ovine milk produced by Merino, Tsigai, Dorper, Lacaune, and British Milk Sheep flocks on four sheep farms located in the eastern part of Hungary. In addition to individual raw milk (IRM) and bulk tank milk (BTM) samples, the udder surface (US) of ewes was also tested for bacteriological quality. A total of 77 US, 77 IRM, and 10 BTM samples were collected in the early morning during regular milking sessions. The samples, kept cooled at temperatures below 4◦C, were delivered to the microbiological laboratory and were examined immediately. The relatively low numbers of bacteria in both US and IRM samples reflected good housing conditions of ewes kept on the four farms studied. However, BTM samples had up to 3.5–4.0 log10 CFU/mL higher mean bacterial counts than their IRM counterparts, and the mean levels of bacteria in BTM on two farms even exceeded the regulatory limit of 6.18 log10 CFU/mL. Further studies need to be performed to clarify this issue.

Open Access: Yes

DOI: 10.3390/ani10071163

Process of inversion in fuzzy interpolation model using fuzzy geometry

Suman Das Ĺaszĺo T. Ḱoczy Debjani Chakraborty

Publication Name: IEEE International Conference on Fuzzy Systems

Publication Date: 2020-07-01

Volume: 2020-July

Issue: Unknown

Page Range: Unknown

Description:

Fuzzy rule interpolation (FRI) predicts an accountable outcome of a possible course of action in sparse fuzzy rule base system (FRBS). However, in real life, we encounter some situations where the antecedent has to be predicted to obtain a desired consequent of FRBS. In this situation, inverse fuzzy rule interpolation (IFRI) or backward fuzzy rule interpolation (BFRI) is used to get the desired outcome. Here a geometry based inverse fuzzy rule base interpolation (GIFRI) is suggested. The mathematical detail of the proposed method is elaborated and its geometrical interpretation is given with the help of fuzzy geometry. It is to be noted that the proposed method ensures that the inverse of the inverse is the original one.

Open Access: Yes

DOI: 10.1109/FUZZ48607.2020.9177698

Fuzzy rulebase parameter determination for stabilized KH interpolation based detection of colorectal polyps on colonoscopy images

Ferenc Lilik Brigita Sziová Raneem Ismail Ĺaszĺo T. Ḱoczy Szilvia Nagy

Publication Name: IEEE International Conference on Fuzzy Systems

Publication Date: 2020-07-01

Volume: 2020-July

Issue: Unknown

Page Range: Unknown

Description:

In the case of computer aided diagnosis it is advantageous to apply such computational intelligence methods, that can be related to direct measured data by means easily understandable to medical experts. Fuzzy reasoning, if the rulebase is generated from plausible statistical parameters of the image to be analysed, is easy to understand thus can be easily accepted by the society.In the case of colorectal polyps, which might develop into colorectal cancer, thus the population-wide screening would be advisable, more methods are available, but none of them is accepted as standard and effective method. A method based on simple statistical parameters and entropies of image segments is presented, and the effect of determining the rulebase parameters on the efficiency of finding the polyp segment is studied for stabilized Koczy-Hirota rule interpolation.

Open Access: Yes

DOI: 10.1109/FUZZ48607.2020.9177839

Evaluation of Questionnaires by Combining Fuzzy Signatures, Factor Analysis and Least Squares Method

Dalia Susniene Marta Konczosne Szombathelyi Szabolcs Ramhap Ojaras Purvinis Ĺaszĺo T. Ḱoczy

Publication Name: Ines 2020 IEEE 24th International Conference on Intelligent Engineering Systems Proceedings

Publication Date: 2020-07-01

Volume: Unknown

Issue: Unknown

Page Range: 215-218

Description:

A survey based on a standard questionnaire on employee satisfaction was carried out in Hungary. The questionnaire was developed by international university research consortium. The qualitative data were collected from 1159 respondents. The subjective and therefore inexact answers represented in the Likert scale were mapped into fuzzy membership degrees. The article presents a method that consists of the combination of factor analysis and the least square method, applied for developing the fuzzy signature characterizing the employees' behavioural engagement.

Open Access: Yes

DOI: 10.1109/INES49302.2020.9147125

Characterisation of Hungarian Cikta sheep based on the control region of mtDNA

Petra Zenke Ákos Maróti-Agóts Károly Tempfli Annus Kata Sáfár László Kovács Endre Harmat Levente András Gáspárdy

Publication Name: Magyar Allatorvosok Lapja

Publication Date: 2020-07-01

Volume: 142

Issue: 7

Page Range: 421-428

Description:

Background: The consideration of the high genetic diversity is indispensable on the course of preservation of endangered animal breeds. Objectives: The authors evaluate the genetic background in the Hungarian native Cikta breed by use of mitochondrial DNA (mtDNA) control region (CR) sequence firstly. Their investigation was carried out in order to serve data for the maintenance of maternal lineages. Materials and Methods: The DNA samples were taken from the descendants of the eldest families by use of founder sampling method based on pedigree (n = 69) in 2015. The primers described by Hiendleder et al. (7) were used to amplify the region of interest (AF010406). Results and Discussion: The control region of mtDNA showed polymorphisms at 32 sites. However, the herds shared 24 polymorphic sites, so the maternal background of the Cikta appears to be genetically uniform. The total number of haplotypes were 13, furthermore, most of the samples belonged to the haplog-roup B of sheep. This fact proves the decisively European maternal origin of the Hungarian Cikta. The average number of pairwise differences (k) and the average nucleotide diversity (ro) were 6.863 and 5.95 × 10-3, respectively. The values of the Cikta population were not significant (p < 0.10) neither by the Tajima D-test (0.107) and by Fu's Fs statistics (2.533), meaning that the greatly reduced population size of the breed known from the breed history did not cause genetic drift, it is in genetic equilibrium regarding its ancient families. The genetic information confirmed the origin of the families/flocks known from the breed history. A more intense focusing on the maternal side is motivated also by the fact that the females are present at greater number than the males, respectively they remain in breeding for a longer period of time, so they can at larger extent be the depositaries of realization and maintenance of genetic diversity.

Open Access: Yes

DOI: DOI not available