Czech Technical University Research Articles

60 let statistiky na Vysoké škole ekonomické v Praze

For all 60 years of the existence of the University of Economics, Prague (UEP) was statistics one of the taught compulsory course, and here also took place the specialized studies of statistics, which predecessor was Statistical and Actuarial engineering at the University of Special Sciences (within the Czech Technical University). The article focuses on the 50's, when at the UEP existed the independent Faculty of Statistics and when the lessons of statistics were difficulty exempted from the Stalinist dogmatism. Between the personalities is mentioned prof. Benedikt Korda (1914-2010), who was the most famous person in the first period of Faculty, (there will be mentioned his remarkable CV), prof. Lubomír Cyhelský (*1929), who was the head of the department in 1962-1990, and prof. Jiří Likeš (1929-1994) as well, who was internationally acclaimed scientists in the theory of probability and mathematical statistics, whose name is used for one of the greatest lecture hall at the University. Since 1991 there exist at the Faculty of Informatics and Statistics the Department of Statistics and Probability (17 internal teachers and 13 internal PhD students), the Department of Economic Statistics (6 + 3) and the Department of Demography (6 + 4).

MAP OF NASCA GEOGLYPHS

Abstract. The Czech Technical University in Prague in the cooperation with the University of Applied Sciences in Dresden (Germany) work on the Nasca Project. The cooperation started in 2004 and much work has been done since then. All work is connected with Nasca lines in southern Peru. The Nasca project started in 1995 and its main target is documentation and conservation of the Nasca lines. Most of the project results are presented as WebGIS application via Internet. In the face of the impending destruction of the soil drawings, it is possible to preserve this world cultural heritage for the posterity at least in a digital form. Creating of Nasca lines map is very useful. The map is in a digital form and it is also available as a paper map. The map contains planimetric component of the map, map lettering and altimetry. Thematic folder in this map is a vector layer of the geoglyphs in Nasca/Peru. Basis for planimetry are georeferenced satellite images, altimetry is created from digital elevation model. This map was created in ArcGis software.

Methodology of transportation project management

All large projects, from their inception to their completion, follow certain procedures, when undergoing evaluations of different designs, while at the same time, assuring project functionality at realistic costs which are acceptable to the owner. To keep project costs within certain parameters, there is a need to begin the project with a realistic budget and to have some reliable pricing data. In addition, during the development phase, the project cost must be recalculated and, if necessary, readjusted. Another way to increase the project value or to decrease the cost is to perform Value Engineering, i.e. an analysis of project functionality, specifications, tender documents and other project aspects by a team of experts. This paper describes Value Engineering and how such experts' efforts would be applied and benefit transportation projects. The methodology of design of logistics terminal is presented, including related transport network as an example of a large transport project for the use of Value Engineering. Transport projects can be classified as financially demanding and also with regard to the project planning as demanding projects. Due to the necessary control of costs for preparation and implementation of these projects, value project management (Value Engineering) is included in the proposed methodology. Furthermore from the engineering phase of the project to the decision-making phase on implementation of the project, a heuristic expert model that is able to determine various cost items without detailed engineering documentation, is included in the proposed methodology. However, this model has to work with the normative of individual components of transport projects based on historical data of implemented projects, forecasts of construction materials and other documents. The result financially is a significantly cheaper version of the project, to the decision-making phase on implementation of the project. Listed methodology for the preparation of transport projects with the inclusion of a heuristic expert model for the preliminary determination of costs and with the inclusion of the value project management (Value Engineering) has not yet been implemented in the Czech Republic. In recent years, the expert team of the Faculty of Transportation Sciences at Czech Technical University in Prague has been working in collaboration with the Ministry of Transport and other entities The norms transportation projects 2008 (MOOS, P. et al. (2007)) Structure of sets of normative standardized of segments of road transport constructions - assessment of the situation in EU countries and other available countries in the form of benchmarking, which will be one of the inputs to the described methodology if doing updates. The implementation of this methodology to real design practice would not be an easy task, but with regard to the amount of investment funds to transportation projects, the impact could be unexpectedly significant.

Fairness in Risky Environments: Theory and Evidence

The relationship between risk in the environment, risk aversion and inequality aversion is not well understood. Theories of fairness have typically assumed that pie sizes are known ex-ante. Pie sizes are, however, rarely known ex ante. Using two simple allocation problems—the Dictator and Ultimatum game—we explore whether, and how exactly, unknown pie sizes with varying degrees of risk (“endowment risk”) influence individual behavior. We derive theoretical predictions for these games using utility functions that capture additively separable constant relative risk aversion and inequity aversion. We experimentally test the theoretical predictions using two subject pools: students of Czech Technical University and employees of Prague City Hall. We find that: (1) Those who are more risk-averse are also more inequality-averse in the Dictator game (and also in the Ultimatum game but there not statistically significantly so) in that they give more; (2) Using the within-subject feature of our design, and in line with our theoretical prediction, varying risk does not influence behavior in the Dictator game, but does so in the Ultimatum game (contradicting our theoretical prediction for that game); (3) Using the within-subject feature of our design, subjects tend to make inconsistent decisions across games; this is true on the level of individuals as well as in the aggregate. This latter finding contradicts the evidence in Blanco et al. (2011); (4) There are no subject-pool differences once we control for the elicited risk attitude and demographic variables that we collect.

Experiments on membrane action of composite floors with steel fibre reinforced concrete slab exposed to fire

The resistance of composite floor structures traditionally composes of the elemental resistance of the concrete slab and that of the composite beams. The fire resistance of a properly designed floor structure increases due to its membrane behaviour. Its evaluation is based on advanced as well as simple design procedures approved by tests, for partially protected floors reaching 60min and more. Composite structures are increasingly reinforced by steel fibres instead of steel bars. Due to an equal distribution of reinforcement steel fibre reinforced concrete (SFRC) achieves better deformation capacity compared to the traditional reinforced concrete even at elevated temperatures. Therefore, questions have been raised about its fire resistance and utilisation of membrane action of the floor.In the last two years, composite SFRC floor slabs at ambient and at elevated temperature have been tested at the Czech Technical University in Prague. At elevated temperatures, the floor was only partially fire protected. Intermediate beams and SFRC slab in steel sheeting remained unprotected. Concrete slabs were reinforced by steel fibres only without added steel bars. The main aim of the tests was to demonstrate the sufficient properties of the SFRC slab in fire. For the fire resistance of the floor slabs, it is important for the material to have sufficient ductility and adequate tensile and shear strength. These material properties of the SFRC allow for the slab to create a different load bearing mechanism, which increases its fire resistance. Hence, the SFRC slabs have been tested at ambient and at elevated temperature with a focus on ductility and tensile strength of the material.

Electrospun Core/Shell Nanofibers: A Promising System for Cartilage and Tissue Engineering?

Author for correspondence: Department of Biophysics, 2nd Faculty of Medicine, Charles University in Prague, V Uvalu 84, 150 06 Prague 5, Czech Republic and Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, v.v.i, Videňska 1083, 142 20 Prague 4, Czech Republic and University Centre for Energy Efficient Buildings (UCEEB), Quality of Indoor Environment, Czech Technical University in Prague, Nam. Sitna 3105, 272 01, Kladno, Czech Republic Tel.: +420 296 442 387 andrea_mickova@labdemo.cz

Lasers in Dentistry: Overview and Perspectives

Photomedicine and Laser SurgeryVol. 31, No. 4 Guest EditorialLasers in Dentistry: Overview and PerspectivesTatjana Dostalova and Helena JelinkovaTatjana DostalovaSecond Medical Faculty, Department of Stomatology, Charles University, Prague, Czech Republic.Search for more papers by this author and Helena JelinkovaFaculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, Prague, Czech Republic.Search for more papers by this authorPublished Online:8 Apr 2013https://doi.org/10.1089/pho.2013.3493AboutSectionsView articleView Full TextPDF/EPUB Permissions & CitationsPermissionsDownload CitationsTrack CitationsAdd to favorites Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail View articleFiguresReferencesRelatedDetailsCited byNon‐surgical mechanical therapy of peri‐implantitis with or without repeated adjunctive diode laser application. A 6‐month double‐blinded randomized clinical trial10 July 2022 | Clinical Oral Implants Research, Vol. 33, No. 9Effect of Er:YAG laser pulse duration on repair bond strength of resin-based and hybrid CAD/CAM restorative materials1 June 2021 | Journal of Adhesion Science and Technology, Vol. 36, No. 6Repair bond strength and surface topography of resin‐ceramic and ceramic restorative blocks treated by laser and conventional surface treatments8 December 2020 | Microscopy Research and Technique, Vol. 84, No. 6Decontamination of Dental Implant Surfaces by the Er:YAG Laser Beam: A Comparative in Vitro Study of Various Protocols1 December 2018 | Dentistry Journal, Vol. 6, No. 4Behavior of human periodontal ligament cells on dentin surfaces ablated with an ultra-short pulsed laser6 October 2017 | Scientific Reports, Vol. 7, No. 1Effect of Er:YAG laser pulse duration on the shear bond strength of bleached dentin24 October 2017 | Journal of Physics D: Applied Physics, Vol. 50, No. 46Microshear Bond Strength of OptiBond All-in-One Self-adhesive Agent to Er:YAG Laser Treated Enamel After Thermocycling and Water Storage18 July 2016 | Journal of Lasers in Medical Sciences, Vol. 7, No. 3Er:YAG laser metal and ceramic bracket debondingA Randomized Clinical Trial of an Adjunct Diode Laser Application for the Nonsurgical Treatment of Peri-Implantitis Volkan Arısan, Zihni Cüneyt Karabuda, Selahattin Volkan Arıcı, Nursen Topçuoğlu, and Güven Külekçi5 November 2015 | Photomedicine and Laser Surgery, Vol. 33, No. 11Short pulse mid-infrared radiation removal of tooth tissueEr:YAG laser radiation: contact versus non-contact enamel ablation and sonic-activated bulk composite placement: microleakage evaluation24 December 2014 | Laser Physics, Vol. 25, No. 2Laser surface engineering in dentistryEr: YAG Laser Contact and Non-Contact Delivery Systems Cavity Preparation and Sonic-Activated Bulk Composite RestorationČeská stomatologie/Praktické zubní lékařství, Vol. 114, No. 3Er:YAG laser delivery sytems and sonic-activated bulk composite restoration: sculpturing and microleakage evaluationThe Current Status of LLLT in the Field of Dental and Oral Surgery -In Anticipation of the Recent Trend and the Concept of LLLT-Nippon Laser Igakkaishi, Vol. 34, No. 4 Volume 31Issue 4Apr 2013 InformationCopyright 2013, Mary Ann Liebert, Inc.To cite this article:Tatjana Dostalova and Helena Jelinkova.Lasers in Dentistry: Overview and Perspectives.Photomedicine and Laser Surgery.Apr 2013.147-149.http://doi.org/10.1089/pho.2013.3493Published in Volume: 31 Issue 4: April 8, 2013Online Ahead of Print:March 14, 2013PDF download

TOOLS FOR VISUALIZATION OF ENERGY FLOWS IN THE CONSTRUCTION OF MACHINE-TOOLS

The article deals with the development of tools supporting a higher degree of visualization in order to assess the workload of electrical appliances installed in machine-tools. A higher degree of visualization means to forward the interpretation of the results from commonly used tables, graphs, and also 2D visualization, to 3D visualization. This enables us a considerably easier orientation in the virtual phase of the design and the control of not only the energy consumption of the machine-tools, but also of their structural nodes. The first part of the article deals with the possibilities and application of 3D visualization including the work with the required input data. There is a detailed description of how to construct the necessary data to create a 3D model, if these data are not available. The second part is concerned with the application created for simulation of energy flows in the machine-tool in dependency on time. There are described some of the obstacles that must be solved and also the benefits of the proposed solutions for the user. Finally, the present article briefly describes possible future developments of the software concerned. The tool developed for visualization was applied to the machine FUEQ 125 Efektiv company TOS Kurim in cooperation with the Czech Technical University in Prague, Faculty of Mechanical Engineering, VCSVTT – Research Centre for Manufacturing Engineering and Technology.

SBToolCZ: Sustainability rating system in the Czech Republic

Several methods for complex assessment of building performance are available in Europe. The Czech Republic has followed the international group Green Building Challenge since 2005 and participated in the development of the international assessment framework SBTool. The Czech Technical University in Prague in cooperation with National Platform SBToolCZ and International Initiative for a Sustainable Built Environment (iiSBE) provides a localised national version of the tool called SBToolCZ for wide usage in building practice in the Czech Republic. This paper presents the Czech assessment methodology SBToolCZ, its structure, system of weights setting and form of final certificate. It also introduces one of the certified residential buildings – X-Loft in Prague – and describes the process of its certification and its main outcomes.

SyRoTek—Distance Teaching of Mobile Robotics

E-learning is a modern and effective approach for training in various areas and at different levels of education. This paper gives an overview of SyRoTek, an e-learning platform for mobile robotics, artificial intelligence, control engineering, and related domains. SyRoTek provides remote access to a set of fully autonomous mobile robots placed in a restricted area with dynamically reconfigurable obstacles, which enables solving a huge variety of problems. A user is able to control the robots in real time by their own developed algorithms as well as being able to analyze gathered data and observe activity of the robots by provided interfaces. The system is currently used for education at the Czech Technical University in Prague, Prague, Czech Republic, and at the University of Buenos Aires, Buenos, Aires, Argentina, and it is freely accessible to other institutions. In addition to the system overview, this paper presents the experience gained from the actual deployment of the system in teaching activities.

Steel Fibre Reinforced Concrete for Tunnel Lining – Verification by Extensive Laboratory Testing and Numerical Modelling

The use of precast steel fibre reinforced concrete (SFRC) for tunnel segments is a relatively new application of this material. It was first applied in Italy in the 1980s. However, it did not begin to be widely applied until after 2000. The Czech Technical University in Prague (CTU), together with Metrostav, carried out a study to evaluate the use of this new technology for tunnels in the Czech Republic. The first tests were carried out on small samples (beams and cubes) produced from SFRC to find an appropriate type and an appropriate dosage of fibres. The tests were also used to verify other factors affecting the final product (e.g. production technology). Afterwards, SFRC segments were produced and then tested at the Klokner Institute of CTU. Successful test results confirmed that it was possible to use SFRC segments for Czech transport tunnels. Consequently a 15 m-long section of segmental lining generated from SFRC without steel rebars was constructed as part of line A of the Prague metro.

Characterization of Human Gait using Fuzzy Logic

In medical practice, there is no appropriate widely-used application of a system based on fuzzy logic for identifying the lower limb movement type or type of walking. The object of our study was to determine characteristics of the cyclogram to identify the gait behavior by using a fuzzy logic system. The set of data for setting and testing the fuzzy logic system was measured on 10 volunteers recruited from healthy students of the Czech Technical University in Prague. The human walking speed was defined by the treadmill speed, and the inclination angle of the surface was defined by the treadmill and terrain slope. The input to the fuzzy expert system is based on the following variables: the area and the inclination angle of the cyclogram. The output variables from the fuzzy expert system are: the inclination angle of the surface, and the walking speed. We also tested the method with input based on the angle of inclination of the surface and the walking speed, and with the output based on the area and the inclination angle of the cyclogram. We found that identifying the type of terrain and walking speed on the basis of an evaluation of the cyclogram could be sufficiently accurate and suitable if we need to know the approximate type of walking and the approximate inclination angle of the surface. According to the method described here, the cyclograms could provide information about human walking, and we can infer the walking speed and the angle of inclination of the terrain.

Transatlantic Dual Masters Degree Program in Transportation and Logistics Systems

In August 2010, the University of Texas at El Paso, the Czech Technical University, and the University of Zilina jointly launched the Transatlantic Dual Master's Degree Program in Transportation and Logistics Systems. Under this program, a graduate student spends 1 year of study at the University of Texas at El Paso and a second year at Czech Technical University or University of Zilina, or vice versa. On successful completion of the 2-year program, a student earns two master's degrees. Two years of effort led to a successful proposal submitted to the funding agencies in the United States and the European Union, followed by 1 year of administrative preparation before the actual student mobility began in August 2011. The first cohort of eight students successfully completed the program in June 2012. This paper reports the sequence of events that led to the proposal submission and award, major issues that surfaced throughout the course of the project, and challenges that were overcome during the administrative preparation phase. The experiences of students and professors who have participated in this program are also documented. Key factors leading to the successful implementation in the initial years are discussed.

Conceptual design and performance simulations of super-compact electromagnetic calorimeter

Measurements of particle production at forward rapidities in high energy p-p, p-A and A-A collisions provide access to physics processes at very low Bjorken x. These measurements will allow to study the gluon saturation scale and improve our knowledge of parton distribution in nuclei. Specific requirements must be fulfilled for a calorimeter to successfully operate in high-multiplicity forward region within often stringent space limits. Here we present a study of a conceptual design of super-compact electromagnetic calorimeter being developed at Czech Technical University in Prague. The design of the sampling calorimeter is based on a sandwich structure of thin tungsten and scintillator layers oriented in parallel to the beam. Used optical readout of individual scintillator pads guaranties the required high radiation hardness of the detector. We present simulation of the expected performance of the optical pad readout together with overall detector performance. It is aimed for the detector to allow measuring of high energy photons (1<E<300 GeV) in forward rapidities (2.5 < η < 4).

Spalling of concrete subjected to blast loading

This paper presents outcomes of the blast field tests of FRC and reinforced concrete specimens, which were performed in cooperation with the Czech Army corps and Police of the Czech Republic in the military training area Boletice. The numerical evaluation of the experiments focused on the spalling of concrete subjected to blast loading started after the first set of the tests, took almost 3 years and required further small-scale experiments performed in the labs of the Czech Technical University. This paper presents outcomes of the blast field tests of FRC and reinforced concrete specimens which were performed in cooperation with the Czech Army corps and Police of the Czech Republic in the military training area Boletice. The test were performed using real scale reinforced concrete precast slabs with varying fiber content and concrete strength class and 25kg of TNT charges placed in distance from the slab for better simulation of real in-situ conditions. The paper presents conclusions from two sets of experiments focused on the spalling of concrete subjected to blast loading and results of their numerical evaluation. The tests were performed in November 2010 and August 2011 at the military training area Boletice. The specimens were cast in Prague and had to be transported almost 200km to the location of the tests. The numerical evaluation of the tests started after the first set of the tests, took almost 3 years and required further small-scale experiments performed in the labs of the Czech Technical University. The evaluation focuses on the extent of concrete spalling of specimens subjected to blast loading.

Preface for Vol 8 FOSS4G Prague

This special issue about the FOSS4G-CEE &amp;amp; Geoinformatics 2012, held for the first time in May 2012, is offering selected reviewed papers of the conference. Geoinformatics FCE CTU, started in 2006 at the Department of Mapping and Cartography, Faculty of Civil Engineering, Czech Technical University in Prague, covered the academic section of FOSS4G-CEE.&lt;br /&gt;The acronym FOSS4G was first introduced in 2004 as an acronym for Free and Open Source Software for Geoinformatics by a Japanese research group in a publication and then used for the GRASS GIS Users Conference held in 2004 in Bangkok, Thailand. Later on this acronym was transferred to Open Source Geospatial Foundation (OSGeo.org) for their annual conference. The FOSS4G-CEE 2012 was the first regional FOSS4G conference in Central and East Europe.&lt;br /&gt;There were more than sixty presentations, six workshops and five tutorials accepted for the conference. Number of registered participants was 120 from twenty countries, namely the Czech Republik (35), Romania (14), Germany (12), France (6), Austria (5), Slovakia (4) and Estonia, Hungary, Switzerland, Poland, Turkey, USA, Italy, United Kingdom, Croatia, Rwanda, New Zealand, Georgia, Ghana and Nigeria (ranging from 3 to 1 participants).

Project-Oriented Study at the Czech Technical University in Prague, Faculty of Transportation Sciences

The article discusses project-oriented study at the Czech Technical University in Prague, Faculty of Transportation Sciences. Study with project-oriented component prepares students of bachelor and master study programmes for their careers by exposing them to concrete problem-solving already during the course of their studies. Work on a project, i.e. on a real task commissioned by an external entity, requires students to apply acquired practical knowledge. Inseparable part of the practical problem-solving is team work with other students, academics and scientists. Project study reinforces preparation of students for solving expert problems in their future jobs and thus significantly increases their employment potential. The article further discusses advantages and disadvantages of project-oriented study and statistical data from the last three project recruitments.

Remote Access to 3D Models for Research, Engineering, and Art

Stereoscopic (3D) models and visualizations can add value to current videoconferencing systems by offering a higher level of immersion when accessing remote 3D models. The low-latency remote access to 3D models in high resolution over high-speed networks could enable more effective collaboration between physically distributed teams in research, engineering, and humanities. Many research fields, from engineering and science to the arts and humanities, could benefit from remote access to 3D models. This article surveys the state of the art in this field as well as the various system architectures available. The authors also describe several experiments conducted over long distances (more than 10,000 km) using prototype systems developed at the Czech Technical University. Their results show that when the low processing delay on the sender and receiver side is added to the inevitable network propagation delay the resulting response time is still acceptable and can provide an interactive feeling.

Design of the Composite Steel-Glass Beams with Semi-Rigid Polymer Adhesive Joint

New and high transparent structural element, steel-glass composite beam was developed in respect to fabrication, static-structural and architectural criteria and consists of steel flanges and glass web assembled together by semi-rigid polymer adhesive, which is the key element of whole composite system. These beams can be used mainly as members of high transparent roof or floor structure as well as stiffening fins for large area glass facades. This paper deals with experimental research performed at CTU (Czech Technical University) Prague, which started by adhesive selection and initial material tests by ISO527, continued via small-scale steel-glass connection tests and graduated by full-scale tests of hybrid beams with the span of 4 m. Generalized results of these experiments, analytical and numerical studies serve as device, how to accurately predict the behavior of the beam, describe the stress distribution along the cross section and safely and economically design such a kind of structure with semi-rigid shear connection, made by polymer adhesive.

BIOMECHANICS SIMULATION HELPS DISPROVE THE UNEQUIVOCAL MURDER

The Laboratory of Biomechanics, Czech Technical University in Prague was approached as the expert institution in forensic biomechanics field. Subject of interest was expert assessment of movement between two humans, because during this movement died one of the persons. Investigated movement was throw person over another person, and thrown person died after ground impact. Legal dispute was if person, who throw aggrieved person over, did it with any intention or not. Party of aggrieved person assert, that person who realized throw, had to use lower extremity for doing the throw, and it was the intention. Person who make the “throw”, assert, that he did not use lower extremity for throwing the aggrieved person over.