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Publikacije (46466)

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K. Vranešić, S. Lakušić, M. Serdar

Rails are a part of track structure where corrosion process inevitably occurs, except if they are fully insulated and devoid of contact with any other part of the structure (sleepers, fastening accessories) or electrolyte like moist soil or water in track structure. Corrosion occurs much faster in the presence of stray currents, which very soon results in the loss of material at the rail foot. The paper presents an overview and description of parameters influencing stray current levels, such as electrical potential in rail and longitudinal rail conductivity, rail-to-earth electrical resistance, electrical conductivity of load-bearing concrete layers of truck structure, and electrical conductivity of soil.

Amel Karic, Andreas Kolbitsch

Die Standsicherheit historischer Mauerwerksbauten muss nicht nur bei gewöhnlichen Einwirkungen, sondern auch während Naturkatastrophen gewährleistet sein. Die seismische Bestandsbewertung der gründerzeitlichen Bausubstanz in Wien ist ein zentrales Thema in der qualitativen sowie konstruktiven Tragwerksbeurteilung. Obwohl der Mauerwerksbau seit vielen Jahrhunderten Anwendung findet, stellt die realistische Tragwerksbewertung eine hochkomplexe Herausforderung dar. Die nach aktuellen Regelwerken zur Nachbemessung herangezogenen Berechnungsmethoden vermögen nur unzureichend das reale Tragverhalten sowie die mögliche Aktivierung der globalen Versagensmechanismen wiederzugeben. Dies führt dazu, dass vereinfachte Nachweise rechnerisch oftmals nur schwer gelingen und zur Kompensation fragwürdige Verstärkungsmaßnahmen ergriffen werden, obwohl der Altbestand bereits einige Beben erlebt und überwiegend schadfrei überstanden hat. Der vorliegende Beitrag befasst sich mit den aktuell zur Erdbebennachbemessung verwendeten Ansätzen und verfolgt den Zweck, Problempunkte aufzuzeigen und sie einem leistungsfähigen, an Versuchsreihen gestützten Materialmodell zur räumlichen Tragwerksanalyse des historischen Altbestandes gegenüberzustellen. Es wird gezeigt, dass die herkömmlichen Berechnungsmethoden für den gemauerten Altbestand ohne Berücksichtigung der Interaktions‐ und Lastumlagerungseffekte sowie der charakteristischen Konstruktionsweise das reale Tragverhalten nur teilweise abbilden. Die Arbeit soll einen Beitrag zur technischen Fachdiskussion zur Erdbebensicherheit des Altbestandes darstellen sowie die Diskussion zur Formulierung realistischer Berechnungsmodelle beleben.

Adnan Brdjanin, Nadja Dardagan, Dzemil Dzigal, Amila Akagić

Object tracking is one of the fundamental tasks in computer vision. It is used almost everywhere: human-computer interaction, video surveillance, medical treatments, robotics, smart cars, etc. Many object tracking methods have been published in recent scientific publications. However, many questions still remain unanswered, such as, which object tracking method to choose for a particular application considering some specific characteristics of video content or which method will perform the best (quality-wise) and which one will have the best performance? In this paper, we provide some insights into how to choose an object tracking method from the widespread OpenCV library. We provide benchmarking results on the OTB-100 dataset by evaluating the eight trackers from the OpenCV library. We use two evaluation methods to evaluate the robustness of each algorithm: OPE and SRE combined with Precision and Success Plot.

I. Gupta, Balsam Rizeq, E. Elkord, S. Vranić, A. Al Moustafa

Human coronaviruses, especially SARS-CoV-2, are emerging pandemic infectious diseases with high morbidity and mortality in certain group of patients. In general, SARS-CoV-2 causes symptoms ranging from the common cold to severe conditions accompanied by lung injury, acute respiratory distress syndrome in addition to other organs’ destruction. The main impact upon SARS-CoV-2 infection is damage to alveolar and acute respiratory failure. Thus, lung cancer patients are identified as a particularly high-risk group for SARS-CoV-2 infection and its complications. On the other hand, it has been reported that SARS-CoV-2 spike (S) protein binds to angiotensin-converting enzyme 2 (ACE-2), that promotes cellular entry of this virus in concert with host proteases, principally transmembrane serine protease 2 (TMPRSS2). Today, there are no vaccines and/or effective drugs against the SARS-CoV-2 coronavirus. Thus, manipulation of key entry genes of this virus especially in lung cancer patients could be one of the best approaches to manage SARS-CoV-2 infection in this group of patients. We herein provide a comprehensive and up-to-date overview of the role of ACE-2 and TMPRSS2 genes, as key entry elements as well as therapeutic targets for SARS-CoV-2 infection, which can help to better understand the applications and capacities of various remedial approaches for infected individuals, especially those with lung cancer.

A. Prapavesis, V. Tojaga, S. Östlund, Aart Willem van Vuure

Abstract In this study, the back calculated compressive properties of flax fibers utilizing the Impregnated Fiber Bundle Test (IFBT) were investigated. The back calculated stress-strain response can be described by the Ramberg-Osgood model. The compressive modulus of the fiber is similar to its tensile modulus. The compressive strength of the fiber is approximately 45 % of its tensile strength. Considering the presence of local fiber kinking within the elementary fibers as well as global fiber kinking due to fiber misalignments and plastic shear deformation in the matrix material, this is a remarkably high value for the compressive strength. Our results indicate that local fiber kinking precedes global fiber kinking. We show that IFBT is a promising method for determining the compressive properties of flax fibers and provides necessary input data for finite element analysis of the compressive failure mechanisms in unidirectional flax fiber reinforced composites.

M. Katica, Z. Obradović, Nasreldin Hassan Ahmed, E. Mehmedika-Suljić, Žana Stanić, Rowida Seifeldin Abdalaziz Mohamed, Emina Dervišević

The coexistence of humans and dogs, in addition to all positive effects, can result in negative effects on human health. A particular risk is posed by a population of stray dogs, that is, dogs without owners and veterinary supervision. A contact with dogs in addition to bites, carries the risk of viral, bacterial and parasitic zoonoses, and can also cause psychological trauma. Children, the elderly and pregnant women are the categories most susceptible to the negative effects of dogs. The aim of the paper was to make an interdisciplinary analysis of the negative effects of dogs on humans. Dog bites cause wounds and dysfunction of damaged tissue, and often lead to various infections. The risks of rabies and tetanus are particularly significant if proper and timely treatment is not performed. Ongoing training for dog owners can significantly reduce the number of bites inflicted by owned dogs, but stray dogs remain a serious social problem and pose potential health risks of some zoonosis. Timely and adequate management of bite wounds and the use of rabies-post-exposure prophylaxis as well as psycho-therapy, where indicated, significantly reduce possible adverse health effects for patients who have been bitten by dogs.

Aim To compare maternal, foetal and neonatal characteristics, and perinatal outcome of preterm and term deliveries in twins pregnancies in order to improve perinatal care in Bosnia and Herzegovina. Methods This retrospective cohort study included pregnant women with twin pregnancy who delivered during the period between 1 January 2012 and 31 December 2018 at the Clinic for Gynaecology and Obstetrics, University Clinical Centre Tuzla. Results During the seven-year period 26 734 deliveries were recorded, out of which 362 (1.35 %) were twin pregnancies, 226 (62.4%) preterm and 136 (37.5%) term ones. In the preterm group 38 (16.8%) pregnancies were assisted medical reproduction, and 16 (11.7%) of those were in the term group. The average birth weight was significantly higher for the first twin in both groups (p<0.00001). Incipient intrauterine foetal asphyxia was more frequent in the preterm group (p<0.05). The most common indication for Caesarean section was abnormalities of foetal presentation and lie, 176 (68.2%) for the overall sample. Conclusion Cornerstone of twin pregnancy antenatal care is to get correct data about amnionicity and chorionicity. Since majority of prenatal data did not have this information we call all obstetricians to declare about amnionicity and chorionicity in twin pregnancies during the first trimester ultrasound examination.

Aim To investigate clinical and obstetrical characteristics, an outcome and a prognosis for pregnant women with diagnosed and treated genital or extragenital cancer and their newborns. Methods This retrospective cohort study included pregnant and childbearing women with a history of cancer diagnosed before pregnancy during the period between 1 January 2014 and 31 December 2018. Data related to the course of pregnancy and childbirth were collected from medical records (mothers' disease history and partogram). The analysis covered clinical and histopathological characteristics of cancers, type of the treatment (surgery, chemotherapy, radiotherapy), demographic data, obstetric characteristics, comorbidities of women, and outcome of the newborns. Results The study recorded 18 414 deliveries, of which 30 (0.16%) were pregnancies in women who had been diagnosed and treated earlier for genital or extragenital cancer. The average age of the women at the time of delivery was 29.43±5.97 years. There were six (20%) women with genital and 24 (80%) with extragenital cancer. The most frequent extra genital cancer was Hodgkin lymphoma, in eight (26.6%) cases; ovarian cancer was the most frequent genital cancer, in four (13.3%) cases. The average time span from the cancer diagnosis and start of the treatment to the delivery was 59.2±44.4 months (5 years) (range 12 months - 15 years). Two (6.6%) women died. Conclusion Our data demonstrate a favourable obstetric and neonatal outcome for women who have survived cancer.

N. Mlačo, Armin Šljivo, Ahmed Mulać, A. Kurtovic-Kozaric, A. Pašić, S. Bešlija, Šejla Cerić, Timur Cerić

Aim To investigate quality of life and exposure to lifestyle risk factors of cancer patients in Bosnia and Herzegovina and a correlation of cancer type with lifestyle risk factors. Methods This was a cross-sectional study conducted on 200 cancer patients from the Clinical Centre of the University of Sarajevo. The respondents completed an anonymous questionnaire consisting of seven sections: basic patient information, physical activity, dietary habits including alternative medicine, tobacco use, alcohol consumption, anxiety, and comorbidities. Results A total of 150 (75%) patients were overweight with 113 (56%) of them being less physically active after the confirmed diagnosis. After the diagnosis, 79 (40%) patients ate less food, and 154 (77%) healthier; 130 (65%) reported consumption of alternative medicine and food supplements, 39 (30%) spent >1/4 of average monthly salary on these products. Majority never consumed alcohol, 135 (68%) and 101 (51%) patients reported history of tobacco use. Being obese was an independent predictor for colorectal carcinoma; being less obese was linked to a decreased risk of breast cancer diagnosis. Physical activity was linked to a decreased risk of lung cancer diagnosis. Many patients (122; 61%) reported having chronic comorbidities, mostly hypertension, while 44 (22%) patients were proven to be clinically anxious. Conclusion Our data suggest lack of public awareness of the consequences of unhealthy lifestyles. Risk factors such as alcohol consumption and tobacco use differed from other European countries. Significance of lifestyle changes after the diagnosis for reducing mortality and cancer recurrence requires further research. Prevention programs and more data are needed.

Aim To examine whether preoperative tumour size may serve as a biomarker for the occurrence of lymphovascular invasion (LVI) in centrally and peripherally located lung adenocarcinoma. Method The study included 261 patients surgically treated for diagnosed lung adenocarcinoma. A ROC curve was used to determine the biomarker potential of tumour size relative to the occurrence of LVI. Binary logistic regression was used to show changes of tumour size impact on the status of LVI. Result Tumour prevalence according to localization had no statistical significance (p=0.464), while the presence of LVI in central, as well as peripheral positions, was statistically significantly different (p<0.001). The area under the curve of 0.978 highlights the fact that tumour size is an excellent marker of the presence of LVI in centrally located adenocarcinomas of the lung. A similar finding was confirmed in peripherally located lung adenocarcinomas with an area below the curve of 0.943. Binary logistical regression showed that in centrally localized adenocarcinomas of the lung, each additional centimetre of tumour growth represents an increase in the likelihood of LVI+ by 17.14 times. In peripherally located adenocarcinomas of the lung, this increase in likelihood of LVI for each centimetre of growth was 5.46 times. Conclusion With a high degree of sensitivity and specificity, preoperative tumour size may serve as an important biomarker and positive predictor of the presence of LVI in lung adenocarcinoma of any location.

Drazen Brdjanin, Aleksandar Vukotic, G. Banjac, D. Banjac, Slavko Maric

The paper presents an approach aimed at automatically deriving the conceptual database model from a set of business process models. The approach proposes the incremental synthesis of the target model by iteratively composing the partial conceptual database models that are derived from the models contained in the source set. The approach is implemented by the AMADEOS tool, which is the first online web-based tool enabling the automatic derivation of the conceptual database model from a set of business process models.

Faruk Pasic, B. Wohlers

Condition monitoring is a fundamental technology that enables predictive maintenance of automation systems. However, as automation systems increase in complexity, the development of condition monitoring software becomes a challenging task that requires extensive knowledge from multiple engineering disciplines. In this context, the identification and specification of condition monitoring software requirements play a key role. Neglecting these tasks often results in costly problems during later stages of systems development. Currently, means to support interdisciplinary requirements engineering within condition monitoring software development are missing. In particular, there is a need for a systematic process that supports modeling condition monitoring requirements. In this paper, we present our solution - a profile based on the extension of the SysML, which is commonly used to engineer requirements in automation systems. The profile allows specification of condition monitoring software requirements and thus enables a more domain-specific requirements engineering approach. We illustrate this approach on a heat exchanger condition monitoring system, explain the particular modeling steps, and present lessons learned.

Andrea Carenzo, M. Serafini, E. Roca, A. Paderno, D. Mattavelli, C. Romani, P. Saintigny, S. Koljenović et al.

Background: Oral premalignant lesions (OPLs) represent the most common oral precancerous conditions. One of the major challenges in this field is the identification of OPLs at higher risk for oral squamous cell cancer (OSCC) development, by discovering molecular pathways deregulated in the early steps of malignant transformation. Analysis of deregulated levels of single genes and pathways has been successfully applied to head and neck squamous cell cancers (HNSCC) and OSCC with prognostic/predictive implications. Exploiting the availability of gene expression profile and clinical follow-up information of a well-characterized cohort of OPL patients, we aim to dissect tissue OPL gene expression to identify molecular clusters/signatures associated with oral cancer free survival (OCFS). Materials and methods: The gene expression data of 86 OPL patients were challenged with: an HNSCC specific 6 molecular subtypes model (Immune related: HPV related, Defense Response and Immunoreactive; Mesenchymal, Hypoxia and Classical); one OSCC-specific signature (13 genes); two metabolism-related signatures (3 genes and signatures raised from 6 metabolic pathways associated with prognosis in HNSCC and OSCC, respectively); a hypoxia gene signature. The molecular stratification and high versus low expression of the signatures were correlated with OCFS by Kaplan–Meier analyses. The association of gene expression profiles among the tested biological models and clinical covariates was tested through variance partition analysis. Results: Patients with Mesenchymal, Hypoxia and Classical clusters showed an higher risk of malignant transformation in comparison with immune-related ones (log-rank test, p = 0.0052) and they expressed four enriched hallmarks: “TGF beta signaling” “angiogenesis”, “unfolded protein response”, “apical junction”. Overall, 54 cases entered in the immune related clusters, while the remaining 32 cases belonged to the other clusters. No other signatures showed association with OCFS. Our variance partition analysis proved that clinical and molecular features are able to explain only 21% of gene expression data variability, while the remaining 79% refers to residuals independent of known parameters. Conclusions: Applying the existing signatures derived from HNSCC to OPL, we identified only a protective effect for immune-related signatures. Other gene expression profiles derived from overt cancers were not able to identify the risk of malignant transformation, possibly because they are linked to later stages of cancer progression. The availability of a new well-characterized set of OPL patients and further research is needed to improve the identification of adequate prognosticators in OPLs.

Nina Slamnik-Kriještorac, M. Peeters, S. Latré, Johann M. Márquez-Barja

The combination of 5G and Multi-access Edge Computing (MEC) technologies can bring significant benefits to vehicular networks, providing means for achieving enhanced Quality of Service (QoS), and Quality of Experience (QoE) of wide variety of vehicular applications. Although beneficial in terms of latency reduction, the edge of the architecture for communication networks produces enormous heterogeneity of network services and resources. This challenge becomes even more severe when different administration domains are taken into consideration. Thus, efficient network Management and Orchestration (MANO) of network resources and services are inevitable. As ETSI provided guidelines and standardization for NFV MANO components, the MEC platform can be used to host network services, while MANO systems are in charge of network service management and orchestration. In this paper, we focus on the specific impact that the Virtualized Infrastructure Manager (VIM) has on the performance of the whole MANO system, used for management and orchestration of MEC services and resources in vehicular networks by enabling the on-demand service instantiation, and service teardown. In our testbed-based evaluation, we measured the network service instantiation and termination delays when evaluating: a) OpenStack and Amazon Web Services (AWS) as VIMs for Open Source MANO (OSM), and b) OpenStack and Docker in case of Open Baton. Such performance analysis with a strong experimental component can serve as a baseline for researchers and industry towards exploiting the opportunities that existing MANO solutions provide.

Č. Zeljković, Predrag Mršić, Bojan Erceg, Đorđe Lekić, Nemanja Kitić, P. Matić, T. Șoimoșan

This paper discusses the problem of powering a remote rural mobile base station using a standalone hybrid renewable energy system. A wind turbine and photovoltaic system are employed as the complementary power generation technologies, while the diesel generator serves as a backup power supply. A battery is required to reduce the impact of intermittency of renewable sources. On the consumption side, along with telecommunication electronic equipment, the consumption of cooling devices as a result of the ambient temperature, is also taken into account. The behavior of the base station in electrical and thermal terms is tested using the sequential Monte Carlo simulation. Adequate models have been used to generate wind, irradiance, and temperature input series, using the monthly averages for calibration, as the statistic information that is widely available in meteorological atlases, even for remote rural locations. The developed software provides all the variables of interest either in the form of chronological diagrams or probability histograms. The simulation platform can also be incorporated as a module of an algorithm for selection of optimal capacity of the generating system elements and for the optimal control of the cooling devices.

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