Scopus

Permanent URI for this collectionhttp://65.108.157.135:4000/handle/123456789/10

Browse

Now showing 1 - 20 of 299

Citation Count: 6
The 1st workshop on model-based verification & validation: Directed acyclic graph modeling of security policies for firewall testing
(2009) Tuglular, T.; Kaya, Ö.; Müftüoǧlu, C.A.; Belli, F.; Tuğlular, Tuğkan; Bilgisayar Mühendisliği Bölümü
Currently network security of institutions highly depend on firewalls, which are used to separate untrusted network from trusted one by enforcing security policies. Security policies used in firewalls are ordered set of rules where each rule is represented as a predicate and an action. This paper proposes modeling of firewall rules via directed acyclic graphs (DAG), from which test cases can be automatically generated for firewall testing. The approach proposed follows test case generation algorithm developed for event sequence graphs. Under a local area network setup with the aid of a specifically developed software for this purpose, generated test cases are converted to network test packets, test packets are sent to the firewall under test (FUT), and sent packets are compared with passed packets to determine test result. © 2009 IEEE.
Citation Count: 225
2019 EACTS Expert Consensus on long-term mechanical circulatory support
(European Association for Cardio-Thoracic Surgery, 2019) Potapov,E.V.; Antonides,C.; Crespo-Leiro,M.G.; Combes,A.; Färber,G.; Hannan,M.M.; Gustafsson,F.
Long-term mechanical circulatory support (LT-MCS) is an important treatment modality for patients with severe heart failure. Different devices are available, and many - sometimes contradictory - observations regarding patient selection, surgical techniques, perioperative management and follow-up have been published. With the growing expertise in this field, the European Association for Cardio-Thoracic Surgery (EACTS) recognized a need for a structured multidisciplinary consensus about the approach to patients with LT-MCS. However, the evidence published so far is insufficient to allow for generation of meaningful guidelines complying with EACTS requirements. Instead, the EACTS presents an expert opinion in the LT-MCS field. This expert opinion addresses patient evaluation and preoperative optimization as well as management of cardiac and non-cardiac comorbidities. Further, extensive operative implantation techniques are summarized and evaluated by leading experts, depending on both patient characteristics and device selection. The faculty recognized that postoperative management is multidisciplinary and includes aspects of intensive care unit stay, rehabilitation, ambulatory care, myocardial recovery and end-of-life care and mirrored this fact in this paper. Additionally, the opinions of experts on diagnosis and management of adverse events including bleeding, cerebrovascular accidents and device malfunction are presented. In this expert consensus, the evidence for the complete management from patient selection to end-of-life care is carefully reviewed with the aim of guiding clinicians in optimizing management of patients considered for or supported by an LT-MCS device. © 2019 The Author(s).
Citation Count: 9
Achieving query performance in the cloud via a cost-effective data replication strategy
(Springer, 2021) Tos, Uras; Mokadem, Riad; Hameurlain, Abdelkader; Ayav, Tolga; Ayav, Tolga; Bilgisayar Mühendisliği Bölümü
Meeting performance expectations of tenants without sacrificing economic benefit is a tough challenge for cloud providers. We propose a data replication strategy to simultaneously satisfy both the performance and provider profit. Response time of database queries is estimated with the consideration of parallel execution. If the estimated response time is not acceptable, bottlenecks are identified in the query plan. Data replication is realized to resolve the bottlenecks. Data placement is heuristically performed in a way to satisfy query response times at a minimal cost for the provider. We demonstrate the validity of our strategy in a performance evaluation study.
Citation Count: 9
Adaptive RTP rate control method
(2011) Tos, U.; Ayav, T.; Ayav, Tolga; Bilgisayar Mühendisliği Bölümü
In this paper, we present an adaptive method for maximizing network bandwidth utilization for the real-time applications. RTP protocol is chosen as the transport protocol and the network utilization is provided by increasing and decreasing the transmission rate of the RTP traffic. Our method employs a PID controller that keeps the RTP packet loss fraction at a predefined reference point. Packet loss fraction parameter is gathered from the RTCP receiver reports and fed into the PID controller that controls the transmission rate of the RTP traffic. Simulations are performed to demonstrate the effectiveness of the method under a bottleneck network configuration with background UDP traffic competing against the RTP traffic for the available bandwidth. © 2011 IEEE.
Citation Count: 487
Advanced heart failure: a position statement of the Heart Failure Association of the European Society of Cardiology
(John Wiley and Sons Ltd, 2018) Crespo-Leiro,M.G.; Metra,M.; Lund,L.H.; Milicic,D.; Costanzo,M.R.; Filippatos,G.; Ruschitzka,F.
This article updates the Heart Failure Association of the European Society of Cardiology (ESC) 2007 classification of advanced heart failure and describes new diagnostic and treatment options for these patients. Recognizing the patient with advanced heart failure is critical to facilitate timely referral to advanced heart failure centres. Unplanned visits for heart failure decompensation, malignant arrhythmias, co-morbidities, and the 2016 ESC guidelines criteria for the diagnosis of heart failure with preserved ejection fraction are included in this updated definition. Standard treatment is, by definition, insufficient in these patients. Inotropic therapy may be used as a bridge strategy, but it is only a palliative measure when used on its own, because of the lack of outcomes data. Major progress has occurred with short-term mechanical circulatory support devices for immediate management of cardiogenic shock and long-term mechanical circulatory support for either a bridge to transplantation or as destination therapy. Heart transplantation remains the treatment of choice for patients without contraindications. Some patients will not be candidates for advanced heart failure therapies. For these patients, who are often elderly with multiple co-morbidities, management of advanced heart failure to reduce symptoms and improve quality of life should be emphasized. Robust evidence from prospective studies is lacking for most therapies for advanced heart failure. There is an urgent need to develop evidence-based treatment algorithms to prolong life when possible and in accordance with patient preferences, increase life quality, and reduce the burden of hospitalization in this vulnerable patient population. © 2018 The Authors. European Journal of Heart Failure © 2018 European Society of Cardiology
Citation Count: 15
Advanced Sensor and Detection Materials
(Wiley Blackwell, 2014) Tiwari A.; Demir, M.M.
Presents a comprehensive and interdisciplinary review of the major cutting-edge technology research areas-especially those on new materials and methods as well as advanced structures and properties-for various sensor and detection devices. The development of sensors and detectors at macroscopic or nanometric scale is the driving force stimulating research in sensing materials and technology for accurate detection in solid, liquid, or gas phases; contact or non-contact configurations; or multiple sensing. The emphasis on reduced-scale detection techniques requires the use of new materials and methods. These techniques offer appealing perspectives given by spin crossover organic, inorganic, and composite materials that could be unique for sensor fabrication. The influence of the length, composition, and conformation structure of materials on their properties, and the possibility of adjusting sensing properties by doping or adding the side-groups, are indicative of the starting point of multifarious sensing. The role of intermolecular interactions, polymer and ordered phase formation, as well as behavior under pressure and magnetic and electric fields are also important facts for processing ultra-sensing materials. The 15 chapters written by senior researchers in Advanced Sensor and Detection Materials cover all these subjects and key features under three foci: 1) principals and perspectives, 2) new materials and methods, and 3) advanced structures and properties for various sensor devices. © 2014 Scrivener Publishing LLC. All rights reserved.
Citation Count: 24
Advances in Electrospun Fiber-Based Flexible Nanogenerators for Wearable Applications
(Wiley-v C H verlag Gmbh, 2021) Arica, Tugce A.; Isik, Tugba; Guner, Tugrul; Horzum, Nesrin; Demir, Mustafa M.; Demir, Mustafa
In today's digital age, the need and interest in personal and portable electronics shows a dramatic growth trend in daily life parallel to the developments in sensors technologies and the internet. Wearable electronics that can be attached to clothing, accessories, and the human body are one of the most promising subfields. The energy requirement for the devices considering the reduction in device sizes and the necessity of being flexible and light, the existing batteries are insufficient and nanogenerators have been recognized a suitable energy source in the last decade. The mechanical energy created by the daily activities of the human body is an accessible and natural energy source for nanogenerators. Fiber-structured functional materials contribute to the increase in energy efficiency due to their effective surface to volume ratio while providing the necessary compatibility and comfort for the movements in daily life with its flexibility and lightness. Among the potential solutions, electrospinning stands out as a promising technique that can meet these requirements, allowing for simple, versatile, and continuous fabrication. Herein, wearable electronics and their future potential, electrospinning, and its place in energy applications are overviewed. Moreover, piezoelectric, triboelectric, and hybrid nanogenerators fabricated or associated with electrospun fibrous materials are presented.
Citation Count: 4
Advances in Model-Based Testing of Graphical User Interfaces
(Elsevier Academic Press inc, 2017) Belli, Fevzi; Beyazit, Mutlu; Budnik, Christof J.; Tuglular, Tugkan; Tuğlular, Tuğkan; Bilgisayar Mühendisliği Bölümü
Graphical user interfaces (GUIs) enable comfortable interactions of the computer-based systems with their environment. Large systems usually require complex GUIs, which are commonly fault prone and thus are to be carefully designed, implemented, and tested. As a thorough testing is not feasible, techniques are favored to test relevant features of the system under test that will be specifically modeled. This chapter summarizes, reviews, and exemplifies conventional and novel techniques for model-based GUI testing.
Citation Count: 15
Aggregation of fillers blended into random elastomeric networks: Theory and comparison with experiments
(2006) Demir M.M.; Menceloglu Y.Z.; Erman, B.
A theoretical model describing aggregation of filler particles in amorphous elastomers is proposed. The model is based on a counting technique originally used in genome analysis to characterize the size and distribution of overlapping segments randomly placed on a DNA molecule. In the present model, the particles are first assumed to aggregate randomly upon mixing into the elastomer and then-sizes are calculated. The sizes and distributions of aggregates are also studied in the presence of attractive interparticle forces. Results of the proposed model are compared with experimental data on silica-filled end-linked poly(dimethyl-siloxane) networks. Comparison of the theory and experiment shows that the random aggregation assumption where no attractive forces exist between the particles is not valid and a significant attraction between the silica particles is needed in the theory to justify the experimental data obtained using atomic force microscopy. For filler content below 1.45 vol.-%, the model agrees, qualitatively, with experiment and shows the increase in cluster size with increasing amount of filler. It also explains the increase in the dispersion of aggregate sizes with increasing amount of filler. © 2006 WILEY-VCH Verlag GmbH & Co. KGaA.
Citation Count: 48
Amidoxime functionalized Polymers of Intrinsic Microporosity (PIM-1) electrospun ultrafine fibers for rapid removal of uranyl ions from water
(Elsevier Science Bv, 2019) Satilmis, Bekir; Isik, Tugba; Demir, Mustafa M.; Uyar, Tamer; Demir, Mustafa
The Polymers of Intrinsic Microporosity (PIM-1) is considered as one of the most promising polymer candidates for adsorption applications owing to its high surface area and the ability to tailor the functionality for the targeted species. This study reports a facile method for the preparation of amidoxime functionalized PIM-1 fibrous membrane (AF-PIM-FM) by electrospinning technique and its practical use for the extraction of U(VI) ions from aqueous systems via column sorption under continuous flow. Fibrous membrane form of amidoxime functionalized PIM-1 (AF-PIM-FM) was prepared by electrospinning method owing to its excellent processability in dimethylformamide. Bead-free and uniform fibers were obtained as confirmed by SEM imaging and average fiber diameter was 1.69 +/- 0.34 mu m for AF-PIM-FM. In addition, electrospun PIM-1 fibrous membrane (PIM-FM) was prepared as a control group. Structural and thermal characterization of powder and membrane forms of the materials were performed using FT-IR, H-1 NMR, XPS, Elemental analyses, TGA, and DSC. The porosity of the samples was measured by N-2 sorption isotherms confirming amidoxime PIM-1 still maintain their porosity after functionalization. Amidoxime functionality along with membrane structure makes AF-PIM-FM a promising material for uranyl adsorption. First, a comparison between powder and membrane form of amidoxime functionalized PIM-1 was investigated using batch adsorption process. Although membrane form has shown slightly lower adsorption performance in the batch adsorption process, the advantage of using the membrane in column adsorption processes makes membrane form more feasible for real applications. In addition, amidoxime modification enhanced the uranium adsorption ability of PIM-FM up to 20 times. The effect of initial concentration and pH were investigated along with regeneration of the adsorbents. AF-PIM-FM was successfully used for five adsorption-desorption cycles without having any damage on the fibrous structure.
Citation Count: 11
The amphibian and reptile species of Bozdaǧ (Ödemiş)
(2004) Kumlutaş,Y.; Özdemir,A.; Ilgaz,Ç.; Tosunoǧlu,M.
The herpetofauna of Bozdaǧ in western Anatolia was investigated. In the study area, 152 samples belonging to 22 species from 14 amphibian and reptile families were described. One of these species is an urodelan, 5 are anurans, 1 is a tortoise, 10 are lizards and 5 are snakes. A specimen of Eumeces schneideri was found at Bozdaǧ for the first time. © TÜBİTAK.
Citation Count: 0
AMWC 2013: Advanced Materials World Congress (izmir, Turkey, September 16-19, 2013)
(2013) Demir, M.M.
[No abstract available]
Citation Count: 12
Anomalous transmittance of polystyrene-ceria nanocomposites at high particle loadings
(Royal Soc Chemistry, 2013) Parlak, Onur; Demir, Mustafa M.; Demir, Mustafa
Optical nanocomposites based on transparent polymers and nanosized pigment particles have usually been produced at low particle concentrations due to the undesirable optical scattering of the pigment particles. However, the contribution of the particles to many physical properties is realized at high concentrations. In this study, nanocomposites were prepared with transparent polystyrene (PS) and organophilic CeO2 nanoparticles using various compositions in which the particle content was up to 95 wt%. The particles, capped by 3-methacryloxypropyltrimethoxysilane (MPS), were dispersed into PS and the transmittance of the spin-coated composite films was examined over the UV-visible region. When the particle concentration was <20 wt%, the transmittance of the films showed a first-order exponential decay as the Rayleigh scattering theory proposes. However, a positive deviation was observed from the decay function for higher particle contents. The improvement in transmittance may be a consequence of interference in the multiple scattering of light by the quasi-ordered internal microstructure that gradually develops as the particle concentration increases.
Citation Count: 20
Apoptotic effects of non-edible parts of Punica granatum on human multiple myeloma cells
(Springer Science and Business Media B.V., 2016) Baran, Yusuf; Neergheen-Bhujun,V.S.; Rummun,N.; Baran,Y.
Multiple myeloma is of great concern since existing therapies are unable to cure this clinical condition. Alternative therapeutic approaches are mandatory, and the use of plant extracts is considered interesting. Punica granatum and its derived products were suggested as potential anticancer agents due to the presence of bioactive compounds. Thus, polypenolic-rich extracts of the non-edible parts of P. granatum were investigated for their antiproliferative and apoptotic effects on U266 multiple myeloma cells. We demonstrated that there were dose-dependent decreases in the proliferation of U266 cells in response to P. granatum extracts. Also, exposure to the extracts triggered apoptosis with significant increases in loss of mitochondrial membrane potential in U266 cells exposed to the leaves and stem extracts, while the flower extract resulted in slight increases in loss of MMP. These results were confirmed by Annexin-V analysis. These results documented the cytotoxic and apoptotic effects of P. granatum extracts on human U266 multiple myeloma cells via disruption of mitochondrial membrane potential and increasing cell cycle arrest. The data suggest that the extracts can be envisaged in cancer chemoprevention and call for further exploration into the potential application of these plant parts. © 2015, International Society of Oncology and BioMarkers (ISOBM).
Citation Count: 1
Application of Human-Robot Interaction Features to Design and Purchase Processes of Home Robots
(Springer international Publishing Ag, 2021) Yapici, Nur Beril; Tuglular, Tugkan; Basoglu, Nuri; Tuğlular, Tuğkan; Bilgisayar Mühendisliği Bölümü
Production of home robots, such as robotic vacuum cleaners, currently focuses more on the technology and its engineering than the needs of people and their interaction with robots. An observation supporting this view is that the home robots are not customizable. In other words, buyers cannot select the features and built their home robots to order. Stemmed from this observation, the paper proposes an approach that starts with a classification of features of home robots. This classification concerns robot interaction with humans and the environment, a home in our case. Following the classification, the proposed approach utilizes a new hybrid model based on a built-to-order model and dynamic eco-strategy explorer model, enabling designers to develop a production line and buyers to customize their home robots with the classified features. Finally, we applied the proposed approach to robotic vacuum cleaners. We developed a feature model for robotic vacuum cleaners, from which we formed a common uses scenario model.
Citation Count: 0
Application of the Law of Minimum and Dissimilarity Analysis to Regression Test Case Prioritization
(Ieee-inst Electrical Electronics Engineers inc, 2023) Ufuktepe, Ekincan; Tuglular, Tugkan; Tuğlular, Tuğkan; Bilgisayar Mühendisliği Bölümü
Regression testing is one of the most expensive processes in testing. Prioritizing test cases in regression testing is critical for the goal of detecting the faults sooner within a large set of test cases. We propose a test case prioritization (TCP) technique for regression testing called LoM-Score inspired by the Law of Minimum (LoM) from biology. This technique calculates the impact probabilities of methods calculated by change impact analysis with forward slicing and orders test cases according to LoM. However, this ordering doesn't consider the possibility that consecutive test cases may be covering the same methods repeatedly. Thereby, such ordering can delay the time of revealing faults that exist in other methods. To solve this problem, we enhance the LoM-Score TCP technique with an adaptive approach, namely with a dissimilarity-based coordinate analysis approach. The dissimilarity-based coordinate analysis uses Jaccard Similarity for calculating the similarity coefficients between test cases in terms of covered methods and the enhanced technique called Dissimilarity-LoM-Score (Dis-LoM-Score) applies a penalty with respective on the ordered test cases. We performed our case study on 10 open-source Java projects from Defects4J, which is a dataset of real bugs and an infrastructure for controlled experiments provided for software engineering researchers. Then, we hand-seeded multiple mutants generated by Major, which is a mutation testing tool. Then we compared our TCP techniques LoM-Score and Dis-LoM-Score with the four traditional TCP techniques based on their Average Percentage of Faults Detected (APFD) results.
Citation Count: 3
An architecture for verification of access control policies with multi agent system ontologies
(2009) Tekbacak, F.; Tuglular, T.; Dikenelli, O.; Tuğlular, Tuğkan; Bilgisayar Mühendisliği Bölümü
Multi-agent systems (MAS) which communicate with intra-domain and inter-domain agent platforms have access control requirements. Instead of a central mechanism, a fine-graned access control mechanism could have been applied to MAS platforms. This paper emphasizes MAS-based domain and security ontologies with XACML-based access control approach for MAS platforms. The domain dependent behaviour and access control parameters in agent ontologies could be combined within a common XACML policy document that is used through different MAS applications. Agent-based access control requirements and common XACML policy documents should be consistent to enforce policies for MAS. To obtain this condition, the translation of organizational policies and platform based policies have to be considered in detail and the verified policy features have to be enforced in MAS to provide access for resources. © 2009 IEEE.
Citation Count: 13
Are the helminth communities from unisexual and bisexual lizards different? Evidence from gastrointestinal parasites of Darevskia spp. in Turkey
(Hungarian Natural History Museum, 2015) Roca,V.; Jorge,F.; Ilgaz,C.; Kumlutaş,Y.; Durmuş,S.H.; Carretero,M.A.
Specimens of three species of parthenogenetic lizards (Darevskia uzzelli, D. bendimahiensis, and D. sapphirina) from northeastern Turkey were examined for gastrointestinal parasites. Only one species, the nematode Spauligodon saxicolae (Pharyngodonidae), was found. The extremely low infection and diversity parameters, falling among the lowest within the Palaearctic saurians, support depauperate helminth communities for these parthenogenetic lacertid lizards. Our results suggest that parthenogenetic Darevskia follow a pattern of parasitism similar to other unisexual lizards (i.e. Aspidocelis). The low rates of infection and diversity may be explained by the decreasing opportunities for interchanging helminths rather than factors of susceptibility of unisexual hosts.
Citation Count: 5
Asthma in the context of global alliance against respiratory diseases (GARD) in Turkey
(AME Publishing Company, 2018) Yorgancioğlu,A.; Gemicioglu,B.; Ekinci,B.; özkan,Z.; Bayram,H.; Ergan,B.; Köktürk,N.
[No abstract available]
Automatic Code Generation with Document Responsibility Collaboration Modelling Method
(Institute of Electrical and Electronics Engineers Inc., 2020) Tuglular, T.; Leblebici, O.; Tuğlular, Tuğkan; Bilgisayar Mühendisliği Bölümü
UML is highly preferred for design in current software development approaches. However, the conceptual gap between entities in business processes and classes in UML designs is not small. To reduce this gap, this paper proposes using documents that are vital to every business. The proposed new method called Document Responsibility Collaboration puts the concept of documents at the center. In the proposed method, documents are meta-models of classes in terms of programming, and at the same time, they are meta-models of relationships in terms of permanence. The proposed Document Responsibility Collaboration method uses the domain concept in which domains are made up of documents, and a document defined in a domain can work with another document in any domain to fulfill its responsibility. Document Responsibility Collaboration method defines a process, which starts at the transition from analysis to design phase and continues to the code generation phase. An example from the order management domain is provided to validate the recommended method. © 2020 IEEE.

Browse

Browsing Scopus by Title