TULTECH Journals
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On A* Graph Search Algorithm Heuristics Implementation Towards Efficient Path Planning in the Presence of Obstacles
No full textNowadays it has become more and more important to reach a destination in a short time, in the shortest path between all the options and possibilities. This need is addressed by different search engines like google maps for example and it is common sense that the user is expecting the result in the least amount of time. The scope of this publication, is to help the reader understand the mechanism behind pathfinding algorithms integrated with heuristics and on how to choose between them in a given case study. Moreover, this paper aims at illustrating, after pathfinding algorithm selection, how to tweak and improve it in order to better fit the given setup scenario. With this respect, it will be shown how the A* algorithm computationally performs in a graph theoretic grid setup, initially in a small one and then, in a graph grid with a 10- fold increase of the initial setup dimensions. This experimental study compares two different heuristics in A* implementation, the Euclidean distance heuristic and the Chebyshev heuristic. Computational time results are compared with respect to the time taken to produce a final result in each case. Moreover, the total number of nodes involved in the path as well as the total cost estimated are considered per each case. These results are further compared with the ones derived when obstacles are introduced in the graph grid setup and how the algorithm will handle such scenarios is illustrated. This paper aims at providing information to researchers so that to understand what analysis needs to be done when selecting heuristics associated with pathfinding algorithms heuristics, and at providing relevant performance metrics regarding shortest path planning estimation between two predefined nodes in a graph grid setup. Moreover, aims at providing information on how the heuristics define the decisionmaking process in the A* algorithm and on how to weight the time/cost factors importance based on specific use cases
Flame Resistance of Hand Made Wool Carpets
No full textHandmade wool carpet production in Albania constitutes an important outcome for local producers. In order to guarantee the continuity of production, the quality of the products should be assured. Apart from various physical and mechanical properties necessary for the production line and long-life usage, the fire resistance of the carpet, in particular concerning flammability, is an important property mentioned in EU regulations. Hence, this paper focuses on testing the flammability of handmade carpets used primarily for floor coverings. In this research project five different handmade carpets, randomly chosen and consisting of sheep and goat fibers, are considered. Samples were tested according to ISO 6941:2003. Based on the obtained results, the tested products demonstrate very good behavior in terms of fire resistance and appear to meet the EU standard regarding the flammability of floor coverings
Interaction Effect of Selected Variables and Perceived Barriers of Performance of Rural SMEs
No full textScientific surveys into performance of small and medium enterprises (SMEs) are gaining increasingly more popularity in emerging countries including South Africa. Rampant failures of these enterprises could be due to various perceived barriers including specific perceived barriers and owner-managers perceived barriers. The present study seeks to evaluate the interaction effect of specific perceived barriers and owner-managers’ perceived barriers on SMEs performance. Two hundred and eighty-two rural ownermanagers of small businesses participated in this empirical survey. Purposive sampling techniques was applied based on personal experiences of owner-managers of small businesses to select the participants for data. Being quantitative study, a self-designed questionnaire with open and closed-ended statements were distributed through a trained field worker to solicit primary data. The Statistical Package for Social Science version 23 was used to analyse data. Primary data analyses focused on descriptive and inferential statistics. In total four null and alternate hypotheses were formulated and assessed aided by a two-way ANOVA to determine the interactions between the selected variables and perceived barriers. Some key outstanding revelations emerged from this study. The performance of small businesses is affected by combinations of age and educational qualifications by owner-managers of small businesses. Besides, the study revealed combined effect of owner-managers perceived barriers and specific perceived barriers impact on business performance
Using Concurrency and File Integrity Verification to Transfer Files from Client to Server
No full textIn this research work it has been provided a method for ensuring the integrity of the data throughout their transfer from the client to the server by computing the checksum of the data on the server and comparing it with the checksum of the data after they have been transferred on the client side. Concurrency (multithreading) is also implemented to enable the data to be delivered in parallel. Various file sizes were used to test our methodology. This method can be used in different enterprises or governmental institutions to ensure their data are not being manipulated during the transmission process. Furthermore, will also serve as a reference for engineers who will be responsible for implementing integrity measures in their systems
Photovoltaic systems for road networks
No full textDecarbonization, energy supply security and sustainability has gained increased attentions globally. This has resulted in increasing integration of renewable energy sources. For instance, a significant penetration of renewable energy both in production and use can be observed in Europe, as its goal is to achieve carbon neutrality by 2050. This is also in line with other strategies proposed to reduce the use of virgin land to be taken and aims for a "no net land take" Europe 2050. The use of renewable energy sources such as solar energy requires significantly more land to generate electricity. This paper presents solutions where already utilised land area for road infrastructure can also be used for solar energy-based power production. Based on extensive review of literature on different concepts for solar cell systems linked to road transport infrastructure, an overall picture of the state-of-the-art and current challenges within this field has been created. Solar roads, PV integrated noise barriers along the motorway and solar roofs for roads are presented with their advantages and technical challenges. Solar PVs and road networks can be a perfect combination to contribute in mitigating the climate impact caused by road transport sector, increased lifespan of road networks and efficient use of land area
An Overview Methodology for Writing Suitable Boolean Rules for Protein Signaling Pathways
No full textBoolean model elaborates discrete modelling of any biological system with the purpose to study its dynamical evolution. The representative network has been composed of nodes and edges that show the way of interactions between these nodes. The modelling consists of a set of logical functions, known as Boolean functions that represent the interactions between nodes, and are simulated to determine all attractors of the system, and consequently, its stable states are stated as fixed points. In this paper, we give a description of the methodology followed to write Boolean functions. We present two different Boolean models constructed by these two methods and the differences shown in the results they simulate. In a situation where experimental data are missing, the functions have been usually written under prediction and assumptions made for this occasion, because the path followed by the information to jump from one node to another was considered mandatory for the first Boolean model. Differently, in the second Boolean model activators and inhibitors are considered separately without any restriction, as in the first method. Here, the type of interactions was considered important, because we are interested to know only what flows in and out from any target node. The methodology has been applied firstly in a hypothetical representative system and then in four real signalling pathways. We have identified many differences in the simulated fixed points and concluded that the second model offers more results for further analysis. Consequently, there is a higher probability that we find, through second Boolean modelling, more suitable stable states that correspond to the biology
Analysis of the motor vehicle fleet as a way to reduce air pollution in the Republic of Kosovo
No full textTransport has been considered a basic activity in social and economic life. Motorized traffic is the most massive activity within any country. The Republic of Kosovo remains the place where cars have been used in almost every destination and purpose of travel. The environmental and health effects of car use are already known throughout the globe, so monitoring and analysis in order to minimize their impact is a necessary and scientific requirement. The composition of the road vehicle inventory will serve as the main input for building the model for fleet renewal as a targeted approach to reducing harmful substances emitted into the atmosphere. The most harmful substance from the combustion of hydrocarbon fuels is CO2, therefore the same serves as an instrument for the necessary reform with the rate of vehicle taxation in the Republic of Kosovo
A Textile RFID Meander Antenna for Military Applications
No full textThis study is focused on the construction of a dipole meander textile antenna that exhibits a stable communication system in military applications. The geometric shape of the antenna was calculated and determined based on the fact that dipole antennas geometry shows the highest performance at the Radio Frequency Identification (RFID) frequency band. The High Frequency Simulator Structure (HFSS) program was used for stimulation of the proposed antenna. The fabrication method chosen for the realization of this antenna is the automatic embroidery method, as this method offers high durability in use. The paper aimed to have a textile antenna to operate in the frequency band 868-970 MHz (frequency band defined by NATO), and this was achieved by the proposed textile antenna
Performance Evaluation Analyses of Recycled Concrete in Albania by using Ultrasonic Pulse Velocity
No full textThis paper is focused on investigation of the possibility of using recycled aggregate in concrete mixes instead of natural aggregate. Our research included the preparation of concrete mixtures with recycled aggregate of concrete and natural fine aggregate. It has been focused on evaluation of compressive strength of old and new concrete, granulometric distribution analysis of recycled concrete, density of new and old concrete, water permeability in concrete, and measuring of Ultrasonic Pulse Velocity (UPV) for our samples. According to experimental results, the use of recycled aggregate in concrete mixes as an alternative to natural aggregate is possible. The experimental results demonstrate that recycled aggregates of concrete can achieve higher durability
Analysing Contact and Non-Contact Methods of Anthropometric Data Collecting in Estonian Rescue Board
No full textThis study investigates different non-contact and contact methods to find a suitable measuring approach for taking body measurements from rescue workers. In the public sector, when ordering a uniform, every employee has to provide the body measurements themselves. This is a difficult task for ordinary consumer. Therefore, most employees give old uniform sizes. However, in the case of changes in industrial patterns of sewed items, it is necessary to know the actual body dimensions. In this article, three methods have been studied: measuring with a measuring tape from the human body, measuring with a body scanner Human Solution 3D and measuring with two different smartphone applications - apps. Forty seven employees of the Rescue Board were measured within a period of two weeks using different methods. After the analysis, the correct measurement instructions were prepared for the employees. The measurement instructions involved a combination of two approaches – tape measuring method and selected mobile app method. Collecting the right anthropometric data helps to produce work clothing of the right size and better fit, optimise the need for stocks and is the basis for creating an online order system for uniforms