Institute of Informatics

Porto Alegre, Brazil

Institute of Informatics

Porto Alegre, Brazil
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Hedvig J.,Medical Faculty UPJS and DFN | Podracka L.,Medical Faculty UPJS and DFN | Potoekova D.,Institute of Informatics
Kidney and Blood Pressure Research | Year: 2010

Aim: It was to establish whether brain natriuretic peptide (BNP) might predict cardiac dysfunction in children with chronic kidney disease (CKD). Methods: The relation between BNP, echocardiography and risk factors (hypertension, anemia, lipids, CRP, hyperparathyroidism) was investigated in 46 children (10 pre-dialysis patients, 14 on dialysis, 11 children with kidney transplants, and 11 healthy controls). Data on BNP were transformed into common logarithms (log10 BNP, log BNP). Results: log BNP was significantly higher in dialysis patients when compared to controls (2.09 ± 0.78 vs. 1.43 ± 0.34 pg/ml, p = 0.012) and patients in the pre-dialysis stage (2.09 ± 0.78 vs. 1.52 ± 0.42 pg/ml, p = 0.039). log BNP in transplanted children was not significantly different from healthy children (2.09 ± 0.78 vs. 1.71 ± 0.46 pg/ml, p = 0.19). Abnormal heart geometry (concentric and eccentric hypertrophy, concentric remodeling) was found in 19 patients (54.28%). A significant correlation was observed between log BNP and ventricular hypertrophy (r = 0.515, p = 0.001). Compared to controls higher log BNP was seen in children with eccentric hypertrophy than in children with concentric hypertrophy (2.178 ± 0.956 vs. 1.496 ± 0.395 pg/ml, p = 0.05, or 1.982 ± 0.618 vs. 1.496 ± 0.395, p = 0.04). Conclusions: BNP might predict an abnormal geometry in children with CKD. © 2010 S. Karger AG.

News Article | December 5, 2016

ISTANBUL--(BUSINESS WIRE)--Turkcell (NYSE:TKC) (BIST:TCELL) has signed a memorandum of understanding (MoU) with Istanbul Technical University (ITU) to strategically cooperate on the development of 5G technologies. Within the frame of the contract signed, Turkcell and ITU will carry out mutual studies in Research & Development and education areas to make Turkey a producing country in 5G technology. Turkcell has signed an agreement to carry out work in partnership with Istanbul Technical University for developing 5G technologies in Turkey. Within the frame of the protocol signed by Istanbul Technical University Rector Prof. Dr. Mehmet Karaca, Turkcell CEO Kaan Terzioğlu and Istanbul Technical University Informatics Institute Director Prof. Dr. Ertugrul Karacuha, Turkcell and Istanbul Technical University are going to carry out mutual R&D studies on 5G. The ultimate aim of ITU and Turkcell in signing this contract is to make Turkey a producing country in 5G technology. "In line with Turkey’s targets for 2023, we will continue our mission of collaboration with industry. R&D activities to be carried out in both application and mobile communication systems will provide significant contribution to the future competitiveness of our country. I would like to emphasize that the project carried out with Turkcell is a start point in this regard." said Prof. Dr. Mehmet Karaca, Istanbul Technical University Rector. "Currently Turkey has one of the most prepared infrastructures in the world for 5G. We, as Turkcell, believe that 5G technologies can be a milestone for our country to become a producing country. And our top-priority target is to see Turkey as the leader of the countries that have developed 5G and to allow it to be an arbiter in this area with our collaboration with ITU. For this purpose, we are going to work together with the best engineers both at our company and at ITU to establish a 5G centre in the campus of the university," said Kaan Terzioğlu, Turkcell CEO. "With ITU and Turkcell collaboration, in regard with 5G we are going to found an open-area test, measurement and research centre and make it available for everyone who carry out R&D activities. We also aim to develop products locally in Turkey and contribute to local production within the frame of new technologies. This will ensure participation in standardization studies in the world for 5G," said Istanbul Technical University Informatics Institute Director Prof. Dr. Ertugrul Karacuha. Within the frame of this collaboration, the plan is to conduct studies for increasing the competitiveness of Turkey in regard with 5G by using The Department of Electronics and Communications Engineering, Computer Engineering Institute of Informatics, High Performance Computing Centre, laboratories and technical infrastructure opportunities at ITU. This collaboration will also provide an excellent opportunity for ITU students to take part in 5G studies and make contributions. ITU and Turkcell are going to act together at scientific events such as conferences, symposiums, seminars, workshops and panel discussions regarding national and international 5G projects, as well as R&D studies. Within the scope of the agreement that ensures cooperation also in the standardisation studies regarding the next generation telecommunications, Turkcell and ITU are going to create an infrastructure at the university for "ITU-Cell Research, Development and Test Environment" to make the Ayazağa Campus of ITU a 5G centre.

Stanciulescu F.,Institute of Informatics
European Control Conference, ECC 1999 - Conference Proceedings | Year: 2015

The hybrid modelling technique of complex systems is a multimodel approach [1,3,8]. A hybrid model is defined as a complex model composed of several interconnected (sub)models of different kinds, i.e. a continuous simulation model and/or a discrete-time simulation model, a discrete event simulation model, a heuristic knowledge-based model and/or a fuzzy knowledge-based model. Such a model is useful in simulation and control of complex systems, i.e. the hybrid simulators of complex systems, and/or the fuzzy control systems of complex processes. © 1999 EUCA.

Erdonmez C.,Technical University of Istanbul | Erdonmez C.,Institute of Informatics | Imrak C.E.,Technical University of Istanbul
Strojniski Vestnik/Journal of Mechanical Engineering | Year: 2011

The aim of this paper is to introduce a new methodology of defining and modeling the nested helical structure (NHS) for wire ropes, and to present an accurate wire rope 3D solid modeling, which can be used for finite element analysis. Both single and nested helical wire parametric equations are presented. Derivation of the Frenet-Serret frame for the helical structures is explained, which enables one to define a normal plane along the centerline of a single helical or nested helical curve in 3D space. Both single helical and nested helical solid structures are generated by sweeping a circle or a quadrilateral by using the moving trihedron along the centerline of the helical geometry. When the length of the NHS is increased, surface quality of the NHS diminishes rapidly and it is not possible to generate a good mesh by using the commercial CAD tools. However, the proposed method introduces a solution of modeling helical structures without length limitation with generating an accurate and valid mesh. Illustrative examples are presented to show the benefits of the proposed modeling procedure by using finite element analysis. © 2011 Journal of Mechanical Engineering. All rights reserved.

Bakeva V.,Institute of Informatics | Dimitrova V.,Institute of Informatics
Communications in Computer and Information Science | Year: 2011

Quasigroup string transformations are already used for designing of several cryptographic primitives. The application of quasigroup transformations as encryption algorithm is based on the previously proved result: the distribution of m-tuples in arbitrary string processed by application of quasigroup E (n)-transformation is uniformly distributed for m ≤ n. In this paper, we give some probabilistic properties of quasigroup processed strings that can be used in cryptanalysis. Namely, we find the distribution of m-tuples in an arbitrary string processed by application of quasigroup E (n)-transformation (m > n). Since this distribution is not uniform, it can be used for statistical attack in order to discover the original message and we give an algorithm for this kind of attack. Suitable experimental results are presented as well. © 2011 Springer-Verlag.

Talu S.,Technical University of Cluj Napoca | Ghazai A.J.,Nassiriya Nanotechnology Research Laboratory NNRL | Stach S.,Institute of Informatics | Hassan A.,Universiti Sains Malaysia | And 2 more authors.
Journal of Materials Science: Materials in Electronics | Year: 2014

The purpose of this study was to analyze surface topography of Pt Schottky contacts on quaternary n-Al0.08In0.08Ga0.84N thin film. To understand how the effect of temperature changes the layers surface, the surface topography was characterized through atomic force microscopy (AFM) and fractal analysis. Pt Schottky contacts grown on nanostructure Al0.08In0.08Ga0.84N thin film grown by molecular beam epitaxy technique on sapphire substrate at annealing temperatures range of 300-500 °C were used. AFM analysis was performed in contact mode, on square areas of 10 × 10 μm2, by using a Nanosurf Easyscan 2 AFM system. Detailed surface characterization of the surface topography was obtained using statistical parameters of 3D surface roughness, according with ISO 25178-2: 2012, provided by the AFM software. The results revealed that the high quality Schottky contact with the Schottky barrier heights and ideality factor of 0.76 and 1.03 respectively can be obtained under 30 min annealing at 400 °C in N2 ambience. The surface roughness of Pt Schottky contacts on quaternary n-Al0.08In 0.08Ga0.84N thin film revealed a fractal structure at nanometer scale. Results obtained by fractal analysis confirm the relationship between the value of the fractal dimension and the statistical surface roughness parameters. AFM and fractal analysis are accurate tools that may assist manufacturers in developing Pt Schottky contacts on quaternary n-Al 0.08In0.08Ga0.84N thin film with optimal surface characteristics and provides different yet complementary information to that offered by traditional surface statistical parameters. © Springer Science+Business Media New York 2013.

Araujo J.E.M.,Federal University of Minas Gerais | Souza S.,Institute of Informatics | Valente M.T.,Federal University of Minas Gerais
IET Software | Year: 2011

Several bug-finding tools have been proposed to detect software defects by means of static analysis techniques. However, there is still no consensus on the effective role that such tools should play in software development. Particularly, there is still no concluding answer to the following question usually formulated by software developers and software quality managers: how relevant are the warnings reported by bug finding tools? The authors first report an in-depth study involving the application of two bug-finding tools (FindBugs and PMD) in five stable versions of the Eclipse platform. Next, in order to check whether the initial conclusions are supported by other systems, the authors describe an extended case study with 12 systems. In the end, it has been concluded that rates of relevance superior to 50 can be achieved when FindBugs is configured in a proper way. On the other hand, in the best scenario considered in the research, only 10 of the warnings reported by PMD have been classified as relevant. © 2011 The Institution of Engineering and Technology.

Couto M.V.,Institute of Informatics | Valente M.T.,Federal University of Minas Gerais | Figueiredo E.,Federal University of Minas Gerais
Proceedings of the European Conference on Software Maintenance and Reengineering, CSMR | Year: 2011

Software Product Line (SPL) is a development paradigm that targets the creation of variable software systems. Despite the increasing interest in product lines, research in the area usually relies on small systems implemented in the laboratories of the authors involved in the investigative work. This characteristic hampers broader conclusions about industry-strength product lines. Therefore, in order to address the unavailability of public and realistic product lines, this paper describes an experiment involving the extraction of a SPL for ArgoUML, an open source tool widely used for designing systems in UML. Using conditional compilation we have extracted eight complex and relevant features from ArgoUML, resulting in a product line called ArgoUML-SPL. By making the extracted SPL publicly available, we hope it can be used to evaluate the various flavors of techniques, tools, and languages that have been proposed to implement product lines. Moreover, we have characterized the implementation of the features considered in our experiment relying on a set of product-line specific metrics. Using the results of this characterization, it was possible to shed light on the major challenges involved in extracting features from real-world systems. © 2011 IEEE.

Budik J.,Institute of Informatics
Proceedings of the 24th International Business Information Management Association Conference - Crafting Global Competitive Economies: 2020 Vision Strategic Planning and Smart Implementation | Year: 2014

The paper works with analysis of this investment strategy in terms of robustness parameters to enter the speculative position, the output of speculative positions, volatility and time filter the proposed investment strategy is using the methods of robustness tests, which are based on testing on different data then were data used for optimization of strategies. Proposed strategy is tested and validated for time period from November 2011 to May 2012 the financial instrument for analysis and application of this strategy should be selected with regarding to sufficient liquidity. Liquidity ensures the participation of varying financial entities, which enter to the market for buying and selling. That is a main reason of fundamental relevance of this strategy the input data are represented by a price of financial instrument Standard and Poor's (S&P) E-mini S&P 500 traded on the Globex as futures contract quoted in U.S. dollars the price movements of financial instruments are quantified to price bars at time intervals of one minute, which can be taken as a sufficiently detailed data for analysis. Each of speculative position is held in time interval from minutes to hours and always before the end of the main trading session is all open positions closed. This type of short-term speculative strategy is defined as intraday trading investment strategy. Intraday trading requires low commissions for more efficiency of investment strategies.

Davceva N.,Institute of Forensic Medicine | Janevska V.,Institute of Pathology | Ilievski B.,Institute of Pathology | Spasevska L.,Institute of Pathology | Popeska Z.,Institute of Informatics
Journal of Forensic and Legal Medicine | Year: 2012

Dilemmas and discussions concerning the diffuse axonal injury (DAI) and still existing in forensic medical practice are as it follows: 1. Whether the occurrence of DAI can indicate the type of traumatic event that has caused the head trauma, 2. Whether the presence of axonal damage in cases of hypoxia, ischaemia and other pathological conditions casts a shadow on the post-mortem pathological diagnosis of DAI and totally negates it, or there are certain clues in the findings that can point to the aetiology of the axonal damage. This paper discusses our findings based on neuropathological examination of 60 forensic cases of closed head injury. The neuropathological examination included: a macroscopic examination of the coronal sections and a microscopic examination involving an immunohistochemical method with antibody against β-amyloid precursor protein. Our findings indicate that DAI, as a clinicopathological entity, is undoubtedly an acceleration-deceleration injury, predominant in road traffic accidents as it is classically outlined, and cases of falling from a considerable height. Our findings point to a certain difference between the features of traumatic and ischaemic axonal damage. In this paper we also investigate the correlation between pathological grades of DAI and the impairment of the brain function before death. © 2012 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

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