Tehnika最新文献

{"title":"Specifications of the modern information system for maintenance of medical equipment in healthcare","authors":"Marko Polak, B. Jakovljevic, Željko Marković, Z. Pendić, Sanja Ivošević","doi":"10.5937/tehnika2304485p","DOIUrl":"https://doi.org/10.5937/tehnika2304485p","url":null,"abstract":"Effective management of the maintenance of medical equipment (ME), especially high-tech one, is one of the main issues for the quality of health care, for the provision of cost-effective health services and for saving , even in developed countries, insufficient resources. Medical equipment maintenance (EM) includes all activities related to ensuring an adequate level of service and limiting the downtime of medical equipment in a healthcare organization. Traditionally, EM is categorized as preventive maintenance (PM) and corrective maintenance (CM). The principle of PM is prediction. PM can be planned and predictive, ie. Just-In-Time (JIT) maintenance. Predictive maintenance can only be applied to new high-tech medical devices that have built-in self-testing. Planned preventive maintenance is carried out in accordance with the maintenance plan for a certain period of time. As a rule, when creating the plan, we follow the manufacturer's recommendations for preventive maintenance of ME given in the technical documentation of the ME, especially in the instructions for the maintenance of the ME. Predictive or JIT maintenance makes it possible to detect and solve the problem before problems and contingencies actually occur, and this is done on the basis of intelligent monitoring and analysis of the state of ME at the right moment, which ensures the optimal time for intervention, so that maintenance performed only when necessary. The information system for the management of the maintenance of ME in healthcare institutions would interconnect healthcare institutions and enable the fast and safe exchange of data and information related to the maintenance of ME and enable the optimal maintenance of ME in healthcare institutions, increasing the availability of this equipment, especially high-tech equipment, with significant reduction of the total cost of maintaining ME (of the order of 30%). One of the main reasons for the unsustainability of the existing approach to the maintenance of ME in the healthcare institutions of Serbia is that each healthcare institution independently takes care of the maintenance of its own ME. This approach is expensive and significantly affects high maintenance costs. This approach needs to change.","PeriodicalId":22484,"journal":{"name":"Tehnika","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71134799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Programming and program verification for robots that perform machining tasks","authors":"S. Zivanovic, Nikola Slavković, S. Tabaković, Z. Dimić","doi":"10.5937/tehnika2302167z","DOIUrl":"https://doi.org/10.5937/tehnika2302167z","url":null,"abstract":"The paper presents the programming and program verification of industrial robots that perform machining tasks. The paper considers the different methods for robot programming and the possibilities for configuring virtual robots for machining simulation and program verification for such tasks.","PeriodicalId":22484,"journal":{"name":"Tehnika","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71133073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The application of modern methods of vibration diagnostics in detecting potential faults in rotating equipment","authors":"Borivoj Novaković, Mića Đurđev, Luka Đorđević, Tamara Šajnović","doi":"10.5937/tehnika2305559n","DOIUrl":"https://doi.org/10.5937/tehnika2305559n","url":null,"abstract":"Industrial systems require absolute productivity in order to achieve maximum profits and meet economic objectives. To accomplish this, systems need to be maintained and diagnosed in an adequate, precise, and reliable manner. Modern diagnostic techniques, such as vibration diagnostics, enable timely action to prevent potential major failures and unplanned downtime, which are the most undesirable costs within a production system. The implementation of vibration diagnostic controls provides a precise and clear picture of the condition of rotating equipment and machinery, such as pumps, compressors, and turbines. By analyzing signals collected from measurement points, the condition of the machines can be determined, and a maintenance plan can be established for the upcoming period.","PeriodicalId":22484,"journal":{"name":"Tehnika","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135612076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nanoplastics in aquatic environments: Origin, separation and characterization: Review","authors":"D. Milojkov, Angelina Mitrović, Danijela Smiljanić, G. Jovanović, M. Sokić","doi":"10.5937/tehnika2301103m","DOIUrl":"https://doi.org/10.5937/tehnika2301103m","url":null,"abstract":"Scientists discovered plastic in the early 1900s, but didn't realize the detrimental effects its fragmentation could have on the environment 100 years later. In particular, nanoplastics (NPs) particles ranging in size from 1 to 100 nm can cause major problems in the living world due to their high specific surface area for the adsorption other polluting substances from water, and their further bioaccumulation through the food chain. There is no distinctive method to identify, characterize, and quantify nanoplastics in aquatic environments. Although many of the methods developed to study microplastics are not directly applicable to nanoplastics, conventional methods of characterizing nanoplastics are usually tedious because they study individual nanoparticles in isolation. Since nanoplastics resulting from the decomposition of microplastics have different properties than engineering plastic nanoparticles, new techniques need to be developed to help us better understand the seriousness of the nanoplastic problem. Nanoplastic can be isolated from the water environment by a combination of filters and ultracentrifugation. A recent publications states that combining microscopy and spectroscopy, supported by chemometric techniques, will alow a better understand he behavior of nanoplastic particles in the environment and organisms. High hopes are placed on microscopies combined with neural networks for the quantification and characterization of nanoplastics in complex systems. This article describes the degradation pathways of plastics and the formation of nanoplastics in aquatic environments, and possible methods for separation and characterization of nanoplastics in relation to recent publications.","PeriodicalId":22484,"journal":{"name":"Tehnika","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71132700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quality control in the technological process of DTK25 production","authors":"Đorđe Đermanović, Dejan Đorđević, A. Pavlović, Dalibor Radosavljević, Jelena Savic","doi":"10.5937/tehnika2303277d","DOIUrl":"https://doi.org/10.5937/tehnika2303277d","url":null,"abstract":"The paper describes the quality management procedure, with an emphasis on the quality control of the technological process of the production of a digital topographic map on a scale of 1:25,000 (DTK25) at the Military Geographical Institute \"General Stevan Bošković\". At the very beginning of the work, the basic concepts from the field of quality management, which are defined within the ISO9000:2015 standard, were covered. The following text provides a brief overview of the entire technological process of DTK25 production in the environment of the central Geospatial database, which takes place through seven interconnected phases. After defining the technological production process, the quality management processes that were directly implemented in the technological process were analyzed. The main part of the work presents the analysis of quality control on a concrete example for each of the phases of the technological process.","PeriodicalId":22484,"journal":{"name":"Tehnika","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71133611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cavitation resistance of refractory samples based on talc and domestic zeolite from the Zlatokop deposit","authors":"A. Alil, Jelena Majstorović-Necković, Sanja Martinović, T. Volkov-Husović","doi":"10.5937/tehnika2303263a","DOIUrl":"https://doi.org/10.5937/tehnika2303263a","url":null,"abstract":"The paper presents the results of the research cavitation erosion behavior of samples based on talc with addition of domestic zeolite from the Zlatokop deposit. Samples based on talc with 15 % of zeolite, from Zlatokop (Vranjska Banja), sintered at 1200ºC were used in this investigation. Resistance to cavitation was monitored by the ultrasonic vibratory cavitation set up with a stationary specimen and measuring respectively determining the specimens' mass loss. Image analysis and Young's modulus of elasticity were used to determine the level of degradation of the sample surface and sample's volume. Obtained results showed good resistance of the refractory samples based on talc and zeolite to the cavitation erosion, which indicates the possibility of application ceramic samples based on talc and zeolite in various areas of industry where the presence of destruction due to the effect of cavitation is expected.","PeriodicalId":22484,"journal":{"name":"Tehnika","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71133942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Error level analysis (ELA)","authors":"D. Raković","doi":"10.5937/tehnika2304445r","DOIUrl":"https://doi.org/10.5937/tehnika2304445r","url":null,"abstract":"ELA (Error Level Analysis) is a digital image analysis technique that has gained popularity in recent years in the field of modern forensics. It is a powerful method that can help experts determine if an image has been altered or manipulated in any way. ELA works by analyzing the levels of compression within an image and identifying areas that have been edited or manipulated at a different level than the rest of the image. This information can be crucial in criminal investigations, where the authenticity of an image can be key to solving a case. In this article, we will explore the use of ELA in modern forensics, its benefits, and limitations, as well as its potential impact on the future of forensic investigation.","PeriodicalId":22484,"journal":{"name":"Tehnika","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71134282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Students' perceptions of air quality: An opportunity for more sustainable urban transport in the medium-sized university city in the Balkans","authors":"N. Jurišević, Miroslav Stojadinović, D. Končalović, M. Josijević, D. Gordić","doi":"10.5937/tehnika2304455j","DOIUrl":"https://doi.org/10.5937/tehnika2304455j","url":null,"abstract":"The way citizens perceive air quality has a huge impact on the public's willingness to contribute agendas that promote a sustainable future. Consequently, the scientific community wonders do the sudden and short-term shifts in air quality (such as one caused by the COVID-19 pandemic) have the potential to induce long-term changes in community behavior. This study is based on the interpretation and analysis of a facultative survey administered to the student population of a medium-sized university city in the Balkans. The study's goal is to identify the types and strengths of factors that influence students' perceptions of air quality. In this regard, six classification algorithms were compared in order to select the one with the best fit between students' demographics, traveling habits, and air quality perception. Individual variable influence revealed that Weekly lectures attendance and Distances students travel determine the perception of air quality more than Gender and Permanent place of residence. According to the study, potential commuting reorganization should target those living 2-4 km from the faculty building. Students who regularly attend lectures are likely to be willing to rely on better-organized public transport. Those who do not, will generally contribute the initiative once the positive effects are evident.","PeriodicalId":22484,"journal":{"name":"Tehnika","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71134369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of contingent/contextual theory: A state-of-the-art review","authors":"V. Spasojević-Brkić, I. Mihajlović","doi":"10.5937/tehnika2301077s","DOIUrl":"https://doi.org/10.5937/tehnika2301077s","url":null,"abstract":"The contingent/contextual approach to the theory and practice of the organization arose in the 60s of the previous century, and its verification and empirical improvement are still ongoing, with increasing topicality and the presence of an increasingly strong trend of quantifying the influence of contingent/contextual factors and the increasing complexity of research with the same aim - it is expected that by mastering the effect of given factors, the overall efficiency of the company can be increased and that standardization in this field can bring great benefits. So far, the best researched and quantified is the impact of company size and technology on organizational structure factors. However, a large number of interdependencies are still not resolved among contingent factors, such as: a) the connection of decentralization with other contingent factors - company size, environment, etc., b) the influence of digitalization on the range of management, c) the direction of the influence of the degree of mass production on the number of hierarchical levels, d) the impact of innovation as a part of strategy on the organizational structure and many others. Various authors try to solve the above-mentioned questions, but the conclusions between them have not been confirmed so far; what's more, numerous results are released to the scientific public, which are mutually contradictory, as shown in the tabular presentation in the paper. In particular, the contribution of the latest version of the ISO 9001 standard from 2015, which for the first time recognizes the context in the given area, should be highlighted. Finally, it can be concluded that the empirical verification and theoretical enrichment of the contingent theory has been going on for decades, with the presence of an increasingly strong trend of quantifying the impact of contingent factors and the increasing complexity of research with the same goal - it is expected that mastering the effect of contingent factors can increase the overall efficiency of the company.","PeriodicalId":22484,"journal":{"name":"Tehnika","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71132920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On stochastic processes in the dynamics of planetary transmissions","authors":"R. Knežević, Branko Đedović, Marko Paić","doi":"10.5937/tehnika2302177k","DOIUrl":"https://doi.org/10.5937/tehnika2302177k","url":null,"abstract":"In addition to the theoretical analysis of the nonlinear dynamics of dissipative mechanical systems with the possibility of stochastic and chaotic processes, the paper also includes a numerical experimental example of a planetary transmission. The most common non-linear effects of operation and their influence on the behavior of the planetary gear as a system were analyzed. A simplified model of planetary gears as dissipative dynamic systems whose operation is a complex dynamic process with different effects was considered. These operating effects can appear in many different ways and can be the cause of stochasticity in the operation of the planetary gear. A numerical analysis of planetary gear lubrication was made, as one of the effects of stochasticity, where turbulent damping occurs. The turbulent damping force, due to oil splashing, is taken to be proportional to the second power of the angular velocity of the sun gear. Based on the experiment, it is concluded that the phase space in this system is not preserved and the system is dissipative because the trajectories spiral down into a certain singularity.","PeriodicalId":22484,"journal":{"name":"Tehnika","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71133250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}