Security analysis and improvements to the psychopass methodBoštjan Brumen
, Marjan Heričko
, Ivan Rozman
, Marko Hölbl
, 2013, izvirni znanstveni članek
Opis: Background: In a recent paper, Pietro Cipresso et al proposed the PsychoPass method, a simple way to create strong passwords that are easy to remember. However, the method has some security issues that need to be addressed.
Objective: To perform a security analysis on the PsychoPass method and outline the limitations of and possible improvements to the method.
Methods: We used the brute force analysis and dictionary attack analysis of the PsychoPass method to outline its weaknesses.
Results: The first issue with the Psychopass method is that it requires the password reproduction on the same keyboard layout as was used to generate the password. The second issue is a security weakness: although the produced password is 24 characters long, the password is still weak. We elaborate on the weakness and propose a solution that produces strong passwords. The proposed version first requires the use of the SHIFT and ALT-GR keys in combination with other keys, and second, the keys need to be 1-2 distances apart.
Conclusions: The proposed improved PsychoPass method yields passwords that can be broken only in hundreds of years based on current computing powers. The proposed PsychoPass method requires 10 keys, as opposed to 20 keys in the original method, for comparable password strength.
Ključne besede: passwords, cryptanalysis, data security
Objavljeno: 02.08.2017; Ogledov: 58; Prenosov: 8
Celotno besedilo (542,01 KB)
Outsourcing medical data analysesBoštjan Brumen
, Marjan Heričko
, Andrej Sevčnikar
, Jernej Završnik
, Marko Hölbl
, 2013, izvirni znanstveni članek
Opis: Background: Medical data are gold mines for deriving the knowledge that could change the course of a single patient’s life or even the health of the entire population. A data analyst needs to have full access to relevant data, but full access may be denied by privacy and confidentiality of medical data legal regulations, especially when the data analyst is not affiliated with the data owner.
Objective: Our first objective was to analyze the privacy and confidentiality issues and the associated regulations pertaining to medical data, and to identify technologies to properly address these issues. Our second objective was to develop a procedure to protect medical data in such a way that the outsourced analyst would be capable of doing analyses on protected data and the results would be comparable, if not the same, as if they had been done on the original data. Specifically, our hypothesis was there would not be a difference between the outsourced decision trees built on encrypted data and the ones built on original data.
Methods: Using formal definitions, we developed an algorithm to protect medical data for outsourced analyses. The algorithm was applied to publicly available datasets (N=30) from the medical and life sciences fields. The analyses were performed on the original and the protected datasets and the results of the analyses were compared. Bootstrapped paired t tests for 2 dependent samples were used to test whether the mean differences in size, number of leaves, and the accuracy of the original and the encrypted decision trees were significantly different.
Results: The decision trees built on encrypted data were virtually the same as those built on original data. Out of 30 datasets, 100% of the trees had identical accuracy. The size of a tree and the number of leaves was different only once (1/30, 3%, P=.19).
Conclusions: The proposed algorithm encrypts a file with plain text medical data into an encrypted file with the data protected in such a way that external data analyses are still possible. The results show that the results of analyses on original and on protected data are identical or comparably similar. The approach addresses the privacy and confidentiality issues that arise with medical data and is adherent to strict legal rules in the United States and Europe regarding the processing of the medical data.
Ključne besede: medical data, disclosure control, medical confidentiality, data analysis, data security
Objavljeno: 02.08.2017; Ogledov: 64; Prenosov: 5
Celotno besedilo (3,34 MB)
Intra-minute cloud passing forecasting based on a low cost iot sensor - a solution for smoothing the output power of PV power plantsPrimož Sukič
, Gorazd Štumberger
, 2017, izvirni znanstveni članek
Opis: Clouds moving at a high speed in front of the Sun can cause step changes in the output power of photovoltaic (PV) power plants, which can lead to voltage fluctuations and stability problems in the connected electricity networks. These effects can be reduced effectively by proper short-term cloud passing forecasting and suitable PV power plant output power control. This paper proposes a low-cost Internet of Things (IoT)-based solution for intra-minute cloud passing forecasting. The hardware consists of a Raspberry PI Model B 3 with a WiFi connection and an OmniVision OV5647 sensor with a mounted wide-angle lens, a circular polarizing (CPL) filter and a natural density (ND) filter. The completely new algorithm for cloud passing forecasting uses the green and blue colors in the photo to determine the position of the Sun, to recognize the clouds, and to predict their movement. The image processing is performed in several stages, considering selectively only a small part of the photo relevant to the movement of the clouds in the vicinity of the Sun in the next minute. The proposed algorithm is compact, fast and suitable for implementation on low cost processors with low computation power. The speed of the cloud parts closest to the Sun is used to predict when the clouds will cover the Sun. WiFi communication is used to transmit this data to the PV power plant control system in order to decrease the output power slowly and smoothly.
Ključne besede: photovoltaic power plant, cloud passing forecasting, algorithm, sensor, Raspberry Pi, camera, wide-angle lens, optical filters, internet of things
Objavljeno: 20.07.2017; Ogledov: 120; Prenosov: 12
Celotno besedilo (8,15 MB)
Web based education tool for neural network robot controlJure Čas
, Darko Hercog
, Riko Šafarič
, izvirni znanstveni članek
Opis: This paper describes the application for teleoperations of the SCARA robot via the internet. The SCARA robot is used by students of mehatronics at the University of Maribor as a remote educational tool. The developed software consists of two parts i.e. the continuous neural network sliding mode controller (CNNSMC) and the graphical user interface (GUI). Application is based on two well-known commercially available software packages i.e. MATLAB/Simulink and LabVIEW. Matlab/Simulink and the DSP2 Library for Simulink are used for control algorithm development, simulation and executable code generation. While this code is executing on the DSP-2 Roby controller and through the analog and digital I/O lines drives the real process, LabVIEW virtual instrument (VI), running on the PC, is used as a user front end. LabVIEW VI provides the ability for on-line parameter tuning, signal monitoring, on-line analysis and via Remote Panels technology also teleoperation. The main advantage of a CNNSMC is the exploitation of its self-learning capability. When friction or an unexpected impediment occurs for example, the user of a remote application has no information about any changed robot dynamic and thus is unable to dispatch it manually. This is not a control problem anymore because, when a CNNSMC is used, any approximation of changed robot dynamic is estimated independently of the remote's user.
Ključne besede: LabVIEW, Matlab/Simulink, neural network control, remote educational tool
Objavljeno: 19.07.2017; Ogledov: 149; Prenosov: 5
Celotno besedilo (792,88 KB)
Interface between macro and nano worldsGregor Škorc
, Riko Šafarič
, David Lukman
, Sirhiy Ivanovich Protsenko
, Simon Zapusek
, 2010, izvirni znanstveni članek
Opis: This paper describes the design of a nanorobotic application which includes: nanorobotic arm, Akiyama sensor system, a vacuum chamber, and an interface tools for the nanorobotic hardware developed using C++ and VRML languages in order to create a desktop virtual-reality environment which improves visualisation and prevents collision of the nanomanipulator hardware with the associated workspace. The presented experiment shows how the used man-machine interface could be used for communication between macro and micro/nano worlds.
Ključne besede: nanorobotics, virtual-reality, sensors system
Objavljeno: 19.07.2017; Ogledov: 104; Prenosov: 5
Celotno besedilo (1,70 MB)
Control and robotics remote laboratory for engineering educationRiko Šafarič
, Mitja Truntič
, Darko Hercog
, Gregor Pačnik
, 2005, izvirni znanstveni članek
Opis: The new tools for education of engineering emerged and one of the most promising is a remote rapid control prototyping (RRCP), which is very useful also for control and robotics development in industry and in education. Examples of introductory remote control and simple robotic. courses with integrated hand, on experiments are presented in the paper. The aim o/: integration of remote hand on experiments into control and/or robotics course is to minimize the gap between the theory and practice to teach students the use of RRCP and to decrease the education costs. Developed RRCP experiments are based on MATLAB/Simulink, xPC target, custom developed embedded target for DSP-2 controller and LabVIEW virtual instrument.
Ključne besede: education of control and robotics, rapid prototyping, remote engineering
Objavljeno: 19.07.2017; Ogledov: 115; Prenosov: 7
Celotno besedilo (1,80 MB)
Growth dynamics and reproductive activity of annual shoots in the walnut cultivar 'Elit'Anita Solar
, Mitja Solar
, Franci Štampar
, 2005, izvirni znanstveni članek
Opis: An architectural analysis of a fruiting branch in the Slovenian variety 'Elit' was conducted during three successive years. The fruit bearing branch was constructed of a three-year-old parent shoot plus all corresponding two-year-old shoots and annual shoots (1Y). The construction of the bearing branch during the time caused a statistically significant increase in the number of annual shoots. The basal diameter and the length of 1Y significantly depended on a year whereas their angles did not. In spite of decreasing length of 1Y, the number of vegetative buds per shoot increased from the first to the third year of observations. The number of nodes was closely correlated with the length of the shoots. Activity points on the 1Y were most often on the apical two or three nodes, what was expressed by a marked acrotony. The number of active points varied as the tree matured. The ratio fruit bearing 1Y ž total 1Y was 0.47 in year 1; 0.18 in year 2; 0.74 in year 3. It points to the slightly alternance. As the tree grew the number of flowering buds per 1Y as well as the number of female flowers per 1Y increased. The results of the three-year-long research show some growth and development rules in the walnut cultivar 'Elit', however, they do not allow a reliable prediction of the following activities. We assume that this will be possible after another three-year-long analysis, with the help of the Hidden Mark Model.
Ključne besede: Juglans regia L., tree architecture, fruiting branch, vegetative growth, bearing potentials, shoots, statistical modelling, Hidden Mark Model
Objavljeno: 13.07.2017; Ogledov: 103; Prenosov: 6
Celotno besedilo (284,30 KB)
Citation context and impact of 'sleeping beauties' in paediatric researchJernej Završnik
, Peter Kokol
, Stefano Del Torso
, Helena Blažun
, 2016, pregledni znanstveni članek
Opis: Objectives: ‘Sleeping beauties’, i.e. publications that are not cited for a long while, present interesting findings in science. This study analysed the citation trends of sleeping beauties in paediatric research.
Methods: The study used bibliometric software to analyse the papers citing sleeping beauties in paediatric research, to understand the context in which paediatric sleeping beauties were finally cited and the impact of these sleeping beauties on paediatric research.
Results: Two paediatric sleeping beauties, addressing medical homes and the transition from paediatric to adult health care, respectively, awakened in response to organizational needs. Both presented novel concepts of paediatric service organization that became important because of an increased need for optimization of services.
Conclusion: All sleeping beauties bring new knowledge that becomes important only after several years. Paediatric sleeping beauties exhibited unique characteristics; however, their presence in paediatric research shows that knowledge acquisition in paediatrics resembles that in other disciplines.
Ključne besede: sleeping beauties, bilbliometrics, citation analysis, pediatrics, paediatrics, publications, research
Objavljeno: 13.07.2017; Ogledov: 124; Prenosov: 6
Celotno besedilo (573,45 KB)