01. Araştırma Çıktıları | TR-Dizin | WoS | Scopus | PubMed

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Citation - WoS: 15
Citation - Scopus: 13
Almost Automorphic Solutions of Discrete Delayed Neutral System
(Academic Press Inc Elsevier Science, 2016) Adıvar, Murat; Koyuncuoglu, Halis Can
We study almost automorphic solutions of the discrete delayed neutral dynamic system x(t + 1) = A(t)x(r) + Delta Q(t, x(t - g(t)) + G(t, x(t), x(t - g(t)) by means of a fixed point theorem due to Krasnoselskii. Using discrete variant of exponential dichotomy and proving uniqueness of projector of discrete exponential dichotomy we invert the equation and obtain some limit results leading to sufficient conditions for the existence of almost automorphic solutions of the neutral system. Unlike the existing literature we prove our existence results without assuming boundedness of inverse matrix A (t)(-1). Hence, we significantly improve the results in the existing literature. We provide two examples to illustrate effectiveness of our results. Finally, we also provide an existence result for almost periodic solutions of the system. (C) 2015 Elsevier Inc. All rights reserved.
Citation - WoS: 64
Citation - Scopus: 76
Automated Patient-Specific Classification of Long-Term Electroencephalography
(Academic Press Inc Elsevier Science, 2014) Kiranyaz, Serkan; İnce, Türker; Zabihi, Morteza; Ince, Dilek
This paper presents a novel systematic approach for patient-specific classification of long-term Electroencephalography (EEG). The goal is to extract the seizure sections with a high accuracy to ease the Neurologist's burden of inspecting such long-term EEG data. We aim to achieve this using the minimum feedback from the Neurologist. To accomplish this, we use the majority of the state-of-the-art features proposed in this domain for evolving a collective network of binary classifiers (CNBC) using multi-dimensional particle swarm optimization (MD PSO). Multiple CNBCs are then used to form a CNBC ensemble (CNBC-E), which aggregates epileptic seizure frames from the classification map of each CNBC in order to maximize the sensitivity rate. Finally, a morphological filter forms the final epileptic segments while filtering out the outliers in the form of classification noise. The proposed system is fully generic, which does not require any a priori information about the patient such as the list of relevant EEG channels. The results of the classification experiments, which are performed over the benchmark CHB-MIT scalp long-term EEG database show that the proposed system can achieve all the aforementioned objectives and exhibits a significantly superior performance compared to several other state-of-the-art methods. Using a limited training dataset that is formed by less than 2 min of seizure and 24 min of non-seizure data on the average taken from the early 25% section of the EEG record of each patient, the proposed system establishes an average sensitivity rate above 89% along with an average specificity rate above 93% over the test set. (C) 2014 Elsevier Inc. All rights reserved.
Citation - WoS: 5
Citation - Scopus: 7
A Closer Insight Into the Causality Between Short Selling Trades and Volatility
(Academic Press Inc Elsevier Science, 2016) Baklacı, Hasan Fehmi; Suer, Omur; Yelkenci, Tezer
This study addresses the Granger causality between short selling activities and stock price volatility in the US stock market, utilizing daily data and advanced methodologies. The results denote a bilateral causality between the short selling trades and the volatility of price changes in the US stock market at individual stock as well as at market level. The bilateral causality relationship persists during different market conjunctures. The findings imply that measures to curb excess price volatility stemming from short selling trades were relatively ineffective and the policy-makers need to impose more stringent restrictions to prevent market destabilization. (C) 2016 Elsevier Inc. All rights reserved.
Citation - WoS: 52
Citation - Scopus: 55
Determinants of Felt Stigma in Epilepsy
(Academic Press Inc Elsevier Science, 2016) Aydemir, N.; Kaya, B.; Yildiz, G.; Oztura, I.; Baklan, B.
The present study aimed to determine the level of felt stigma, overprotection, concealment, and concerns related to epilepsy in different life domains by using culturally-specific scales for Turkish individuals with epilepsy. Also, it aimed to detect relations among the study variables and to determine the variables which predict felt stigma. For this purpose, felt stigma scale, overprotection scale, concealment of epilepsy scale, and concerns of epilepsy scale were administered to two hundred adult persons with epilepsy (PWE). The results showed that almost half of the participants reported felt stigma, overprotection, concealment of epilepsy, concerns related to future occupation, and concerns related to social life. Almost all the study variables show correlations with each other. Concealment of epilepsy, concerns related to social life, and concerns related to future occupation were found as the predictors of felt stigma. (C) 2016 Elsevier Inc. All rights reserved.
Citation - WoS: 12
Citation - Scopus: 13
The Discrimination of Raw and Uht Milk Samples Contaminated With Penicillin G and Ampicillin Using Image Processing Neural Network and Biocrystallization Methods
(Academic Press Inc Elsevier Science, 2013) Unluturk, Sevcan; Pelvan, Merve; Unluturk, Mehmet S.
This paper utilized a neural network for texture image analysis to differentiate between milk, either raw or ultra high temperature (UHT) with antibiotic residues (e.g., penicillin G and ampicillin) and milk without antibiotic residues. The biocrystallization method was applied to obtain biocrystallogram images for milk samples spiked with penicillin G and ampicillin at different concentration levels. The biocrystallogram images were used as an input for a designed neural network called the image processing neural network (ImgProcNN). The visual differences in these images that were based on textural properties, including the distribution of crystals on the circular grass underlay, the thin or thick structure of the crystal needles, and the angles between the branches and the side needles, were used to discriminate the antibiotic-free milk samples from samples with antibiotic residues. The visual description and definition of these images have major disadvantages. In this study, the ImgProcNN was developed to overcome the shortcomings of these visual descriptions and definitions. Overall, the neural network achieved an average recognition performance between 86% and 100%. This high level of recognition suggests that the neural network used in this paper has potential as a method for discriminating raw and UHT milk samples contaminated with different antibiotics. (C) 2013 Elsevier Inc. All rights reserved.
Citation - WoS: 14
Citation - Scopus: 14
Effect of Adipocyte-Secreted Factors on Epcam+/Cd133+hepatic Stem Cell Population
(Academic Press Inc Elsevier Science, 2016) Karagonlar, Zeynep Firtina; Koc, Dogukan; Sahin, Eren; Avci, Sanem Tercan; Yilmaz, Mustafa; Atabey, Nese; Erdal, Esra
Recent epidemiological studies have associated obesity with a variety of cancer types including HCC. However, the tumor initiating role of obesity in hepatocarcinogenesis is still unknown. The objective of this paper is to investigate the effect of adipocyte-secreted factors on EpCAM+/CD133+ cancer stern cells and to identify which factors play a role in modulating hepatic cancer stem cell behavior. Our results demonstrated that adipocyte-secreted factors affect motility and drug resistance of EpCAM+/CD133+ cells. When incubated with adipocyte conditioned media, EpCAM-F/CD133+ cells exhibited augmented motility and reduced sorafenib-induced apoptosis. Using array-based system, we identified secretion of several cytokines such as IL6, IL8 and MCP1 by cultured adipocytes and activation of c-Met, STAT3 and ERK1/2 signaling pathways in EpCAM-F/CD133+ cells incubated with adipocyte conditioned media. Treating EpCAM+/CD133+ cancer stem cells with IL6 receptor blocking antibody or c-Met inhibitor SU11274 both reduced the increase in motility; however SU11274 had greater effect on relieving protection from sorafenib-induced apoptosis. These results indicate that adipocyte-secreted factors might regulate cancer stem cell behavior through several signaling molecules including c-Met, STAT3 and ERK1/2 and inhibition of these signaling pathways offer novel strategies in targeting the effect of adipose derived cytokines in cancer. (C) 2016 Elsevier Inc. All rights reserved.
Citation - WoS: 3
Citation - Scopus: 4
Enhancement of Methane Production by Electrohydrolysis Pretreatment for Anaerobic Digestion of Ofmsw
(Academic Press Inc Elsevier Science, 2024) Kabakcı, Yağmur; Koşar, Şadiye; Doğan, Özgür; Üçtuğ, Fehmi Görkem; Arıkan, Osman Atilla
Hydrolysis is the most critical rate-limiting step in the anaerobic digestion (AD) process for most types of substrates. The organic fraction of municipal solid waste (OFMSW) is a rich source for the AD process because of its high degradability. In this study, electrohydrolysis pretreatment was investigated for the OFMSW to overcome the rate-limiting step of hydrolysis. Electrohydrolysis pretreatment was applied to the OFMSW for 30 and 60 min in a custom-made reactor. In the untreated, 30-min. treated, and 60-min. treated OFMSW average methane production was observed as 225 +/- 2 mL CH4/g VSadded, 231 +/- 4 mL CH4/g VSadded, and 248 +/- 7 mL CH4/g VSadded, respectively. By increasing the treatment time, the lag phase, during which hydrolysis occurs, was reduced by 40-43%. 3-10% more methane was produced by applying electrohydrolysis pretreatment. These results suggest that electrohydrolysis pretreatment is a promising method to improve the efficiency of AD for the OFMSW by reducing the time required for hydrolysis and increasing methane production. More investigation is required to better comprehend the effects of electrohydrolysis on the OFMSW.
Citation - WoS: 4
Citation - Scopus: 5
Exploring visual dictionaries: A model driven perspective
(Academic Press Inc Elsevier Science, 2017) Aslan, Sinem; Akgul, Ceyhun Burak; Sankur, Bulent; Tunali, E. Turhan
Good representative dictionaries is the most critical part of the BoVW: Bag of Visual Words scheme, used for such tasks as category identification. The paradigm of learning dictionaries from datasets is by far the most widely used approach and there exists a plethora of methods to this effect. Dictionary learning methods demand abundant data, and when the amount of training data is limited, the quality of dictionaries and consequently the performance of BoVW methods suffer. A much less explored path for creating visual dictionaries starts from the knowledge of primitives in appearance models and creates families of parametric shape models. In this work, we develop shape models starting from a small number of primitives and develop a visual dictionary using various nonlinear operations and nonlinear combinations. Compared with the existing model-driven schemes, our method is able to represent and characterize images in various image understanding applications with competitive, and often better performance.
Citation - WoS: 49
Citation - Scopus: 44
Familiarity With, Knowledge Of, and Attitudes Toward Epilepsy in Turkey
(Academic Press Inc Elsevier Science, 2011) Aydemir, Nuran
The aims of the study described here were to investigate familiarity with, knowledge of, and attitudes toward epilepsy and to assess indicators of positive attitudes toward epilepsy. Questionnaires previously developed for the Turkish population were used to assess knowledge and attitudes. Data were collected from 1354 randomly selected adults. Three-quarters of the sample had heard something about epilepsy, and almost half of the sample personally knew someone with epilepsy. The sample had a moderate level of knowledge of and favorable attitudes toward epilepsy in general. Variables that predicted positive attitudes were young age, male gender, and high level of knowledge of epilepsy. The results for both knowledge and attitudes indicate that the findings of the study are largely in line with previous studies, but where there is wide variability among previous findings, the findings for the Turkish population lie, just as Turkey does geographically, between those of the East and West. (C) 2010 Elsevier Inc. All rights reserved.
Flat Minimal Quantizations of Stackel Systems and Quantum Separability
(Academic Press Inc Elsevier Science, 2014) Blaszak, Maciej; Domanski, Ziemowit; Silindir, Burcu
In this paper, we consider the problem of quantization of classical Stackel systems and the problem of separability of related quantum Hamiltonians. First, using the concept of Stackel transform, natural Hamiltonian systems from a given Riemann space are expressed by some flat coordinates of related Euclidean configuration space. Then, the so-called flat minimal quantization procedure is applied in order to construct an appropriate Hermitian operator in the respective Hilbert space. Finally, we distinguish a class of Stackel systems which remains separable after any of admissible flat minimal quantizations. (C) 2014 Elsevier Inc. All rights reserved.
Citation - WoS: 3
Citation - Scopus: 6
Image declipping: Saturation correction in single images
(Academic Press Inc Elsevier Science, 2022) Karakaya, Diclehan; Ulucan, Oguzhan; Turkan, Mehmet
High dynamic range (HDR) images present fine details in a scene and are visually more appealing than low dynamic range (LDR) images, since they contain a greater dynamic range of color gamut. HDR compatible displays are currently high-cost, therefore tone-mapping algorithms have widely been used to obtain high quality images for LDR screens with a lower cost. However, tone-mapped images may contain clipped pixel regions, which should be corrected to retrieve the lost information, to acquire visually pleasing LDR images. In a single image, the recovery of color and texture information in clipped regions is challenging, yet an attractive research field in image processing. Although there are several algorithms present in literature, developing a general framework for different types of image content is hard to achieve. This study proposes a single image declipping method based on linear embeddings, difference of pixels and block-search. Experimental results carried out on a tone-mapped HDR image dataset and LDR images demonstrate that the proposed algorithm is able to successfully recover saturated pixels in various types of images. Detailed statistical and visual comparisons show that this approach produces superior results on average for both tone-mapped and LDR images when compared to existing techniques.(c) 2022 Elsevier Inc. All rights reserved.
Citation - WoS: 4
Citation - Scopus: 7
Influence of Vestibular Signals on Bodily Self-Consciousness: Different Sensory Weighting Strategies Based on Visual Dependency
(Academic Press Inc Elsevier Science, 2021) Tekgun, Ege; Erdeniz, Burak
Previous studies showed that the vestibular system is crucial for multisensory integration, however, its contribution to bodily self-consciousness more specifically on full-body illusions is not well understood. Thus, the current study examined the role of visuo-vestibular conflict on a fullbody illusion (FBI) experiment that was induced during a supine body position. In a mixed design experiment, 56 participants underwent through a full-body illusion protocol. During the experiment, half of the participants received synchronous visuo-tactile stimulation, and the other half received asynchronous visuo-tactile stimulation, while their physical body was lying in a supine position, but the virtual body was standing. Additionally, the contribution of individual sensory weighting strategies was investigated via the Rod and Frame task (RFT), which was applied both before (pre-FBI standing and pre-FBI supine) and after the full-body illusion (post-FBI supine) protocol. Subjective reports of the participants confirmed previous findings suggesting that there was a significant increase in ownership over a virtual body during synchronous visuo-tactile stimulation. Additionally, further categorization of participants based on their visual dependency (by RFT) showed that those participants who rely more on visual information (visual field dependents) perceived the full-body illusion more strongly than non-visual field dependents during the synchronous visuo-tactile stimulation condition. Further analysis provided not only a quantitative demonstration of full-body illusion but also revealed changes in perceived selforientation based on their field dependency. Altogether, findings of the current study make further contributions to our understanding of the vestibular system and brought new insight for individual sensory weighting strategies during a full-body illusion.
Citation - WoS: 8
Citation - Scopus: 12
Managing Cohort Movement of Mobile Sensors Via Gps-Free and Compass-Free Node Localization
(Academic Press Inc Elsevier Science, 2010) Akcan, Hüseyin; Kriakov, Vassil; Bronnimann, Herve; Delis, Alex
A critical problem in mobile ad hoc wireless sensor networks is each node's awareness of its position relative to the network. This problem is known as localization. In this paper, we introduce a variant of this problem, directional localization, where each node must be aware of both its position and orientation relative to its neighbors. Directional localization is relevant for applications that require uniform area coverage and coherent movement. Using global positioning systems for localization in large scale sensor networks may be impractical in enclosed spaces, and might not be cost effective. In addition, a set of preexisting anchors with globally known positions may not always be available. In this context, we propose two distributed algorithms based on directional localization that facilitate the collaborative movement of nodes in a sensor network without the need for global positioning systems, seed nodes or a preexisting infrastructure such as anchors with known positions. Our first algorithm, GPS-free Directed Localization (GDL) assumes the availability of a simple digital. compass on each sensor node. We relax this requirement in our second algorithm termed GPS- and Compass-free Directed Localization (GCDL). Through experimentation, we demonstrate that our algorithms scale well for large numbers of nodes and provide convergent localization over time, despite errors introduced by motion actuators and distance measurements. In addition, we introduce mechanisms to preserve swarm formation during directed sensor network mobility. Our simulations confirm that, in a number of realistic scenarios, our algorithms provide for a mobile sensor network that preserves its formation over time, irrespective of speed and distance traveled. We also present our method to organize the sensor nodes in a polygonal geometric shape of our choice even in noisy environments, and investigate the possible uses of this approach in search-and-rescue type of missions. (C) 2010 Elsevier Inc. All rights reserved.
Citation - WoS: 8
Citation - Scopus: 11
A Multigroup Multitrait-Multimethod Study in Two Countries Supports the Validity of a Two-Factor Higher Order Model of Personality
(Academic Press Inc Elsevier Science, 2012) Simsek, Omer Faruk; Koydemir, Selda; Schuetz, Astrid
This study examined the factor structure of the Big Five Inventory and tested the hypothesis that the five personality dimensions could be summarized by two higher order factors, namely, plasticity and stability, using multigroup multitrait-multimethod confirmatory factor analyses. We tested the higher order model in two young adult samples drawn from Germany and Turkey. Adequate inter-rater agreement between self- and informant reports was obtained. Among the models tested, a two-factor model was the most parsimonious model in which the first factor included Agreeableness. Conscientiousness, and low Neuroticism: and the second factor included Extraversion and Openness to Experience. Invariance of this model was supported by multiple-group analyses, suggesting a lack of variability across samples. (C) 2012 Elsevier Inc. All rights reserved.
Citation - WoS: 47
Citation - Scopus: 48
Multiple Impacts of Epilepsy and Contributing Factors: Findings From an Ethnographic Study in Vietnam
(Academic Press Inc Elsevier Science, 2009) Aydemir, Nuran; Dang Vu Trung; Snape, Dee; Baker, Gus A.; Jacoby, Ann
We investigated issues related to treatment, impact of epilepsy, attitudes toward epilepsy, and disclosure in Vietnam through in-depth interviews with people with epilepsy (PWE) and their family members. We found that although participants prefer Western to traditional treatment, they experience problems in accessing different kinds of antiepileptic drugs and higher-level treatment facilities and with respect to treatment expenses. The impact of epilepsy can be observed in a wide range of daily living activities which include working, education, marriage, and family formation. Although both families and society at large do not hold negative attitudes toward epilepsy, most PWE reported a sense of burden to others. Both PWE and family members generally prefer disclosing epilepsy rather than concealing it from others. Our findings strongly suggest a need in Vietnam for different types of antiepileptic drugs and epilepsy support information for PWE, family members, and the general public. (C) 2009 Elsevier Inc. All rights reserved.
Citation - WoS: 2
Citation - Scopus: 6
Multirectangular Characteristic Invariants for Power L-Kothe Spaces of First Type
(Academic Press Inc Elsevier Science, 2007) Karapinar, Erdal
Let l be a Banach sequence space with a monotone norm \\ center dot \\(l), in which the canonical system (e(i)) is a normalized unconditional basis. We consider the problem of quasi-diagonal isomorphism of first type power l-Kothe spaces E-l (lambda, a) (see (1) below). From [P.A. Chalov, V.P. Zahariuta, On quasi-diagonal isomorphism of generalized power spaces, in: Linear Topological Spaces and Complex Analysis, vol. 2, METU - TUBITAK, Ankara, 1995, pp. 35-44; P.A. Chalov, T. Terzioglu, V.P. Zahariuta, First type power Kothe spaces and m-rectangular invariants, in: Linear Topological Spaces and Complex Analysis, vol. 3, METU - TUBITAK, Ankara, 1997, pp. 30-44; P.A. Chalov, T. Terzioglu, V.P. Zahariuta, Multirectangular invariants for power Kothe spaces, J. Math. Anal. Appl. 297 (2004) 673-695] it is known that the system of all m-rectangle characteristics mu(m) (see (9) below) is a complete quasi-diagonal invariant on the class of all first type power Kothe spaces [V.P. Zahariuta, On isomorphisms and quasi-equivalence of bases of power Kothe spaces, Soviet Math. Dokl. 16 (1975) 411-414; V.P. Zahariuta, Linear topologic invariants and their applications to isomorphic classification of generalized power spaces, Turkish J. Math. 20 (1996) 237-289], if the relation of equivalency of systems (mu(X)(m)) and (mu((X) over tilde)(m)) is defined by some natural estimates with constants independent of m. Deriving the characteristic (beta) over tilde from the characteristic beta (see [V.P. Zahariuta, Linear topological invariants and isomorphisms of spaces of analytic functions, in: Matem. Analiz i ego Pril., vol. 2, Rostov Univ., Rostov-on-Don, 1970, pp. 3-13 (in Russian), in: Matem. Analiz i ego Pril., vol. 3, Rostov Univ., Rostov-on-Don, 1971, pp. 176-180 (in Russian); V.P. Zahariuta, Generalized Mityagin invariants and a continuum of mutually nonisomorphic spaces of analytic functions, Funktsional. Anal. i Prilozhen. 11 (1977) 24-30 (in Russian); V.P. Zahariuta, Compact operators and isomorphisms of Kothe spaces, in: Aktualnye Voprosy Matem. Analiza, vol. 46, Rostov Univ., Rostov-on-Don, 1978, pp. 62-71 (in Russian); P.A. Chalov, P.B. Djakov, V.P. Zahariuta, Compound invariants and embeddings of Cartesian products, Studia Math. 137 (1) (1999) 33-47; P.B. Djakov, M. Yurdakul, V.P. Zahariuta, Isomorphic classification of Cartesian products, Michigan Math. J. 43 (1996) 221-229; V.P. Zahariuta, Linear topologic invariants and their applications to isomorphic classification of generalized power spaces, Turkish J. Math. 20 (1996) 237-289], and using the S. Krein's interpolation method of analytic scale, we are able to generalize some results of [P.A. Chalov, V.P. Zahariuta, On quasi-diagonal isomorphism of generalized power spaces, in: Linear Topological Spaces and Complex Analysis, vol. 2, METU - TUBITAK, Ankara, 1995, pp. 35-44; P.A. Chalov, T. Terzioglu, V.P. Zahariuta, First type power Kothe spaces and m-rectangular invariants, in: Linear Topological Spaces and Complex Analysis, vol. 3, METU - TUBITAK, Ankara, 1997, pp. 30-44; P.A. Chalov, T. Terzioglu, V.P. Zahariuta, Multirectangular invariants for power Kothe spaces, J. Math. Anal. Appl. 297 (2004) 673-695]. (C) 2007 Elsevier Inc. All rights reserved.
Citation - WoS: 13
Citation - Scopus: 18
A New Cnn Training Approach With Application To Hyperspectral Image Classification
(Academic Press Inc Elsevier Science, 2021) Kutluk, Sezer; Kayabol, Koray; Akan, Aydin
Three main requirements of a successful application of deep learning are the network architecture, a large enough training dataset, and a good optimization algorithm. In this paper we mainly focus on the optimization part. We propose a training algorithm for convolutional neural networks which makes use of both first and second order derivatives for training different layers. We utilize an approximate second order algorithm for the classification layer while we train the rest of the network with the conventional approach which is backpropagation with first order derivatives. We show that this approach helps us achieve a higher classification accuracy with a much smaller number of training iterations compared to training the whole network with gradient descent based algorithms. Moreover, although second order optimization is generally costlier, we show that the proposed approach is trained faster not only in terms of the number of iterations but also training duration. We also present the integration of CNNs with a probabilistic spatial model and apply this to the land cover classification problem in hyperspectral images. The results show that the algorithm allows us to achieve superior results with a simple network even with limited training data compared to existing approaches. (C) 2021 Elsevier Inc. All rights reserved.
On Generators of the Hilbert Ideal for Cyclic Groups in Modular Invariant Theory
(Academic Press Inc Elsevier Science, 2015) Erkuş, DENİZ ERDEMİRCİ; Madran, Ugur
Let G be a cyclic group of order p(2) and V be a faithful indecomposable representation of G over a field F of characteristic p. We show that the Hilbert ideal of the invariant ring is generated by polynomials of degree at most |G| whenever dim V <= 4p or dim V >= p(2) - 2p, proving a conjecture of Derksen and Kemper in this particular case. (C) 2014 Elsevier Inc. All rights reserved.
Citation - WoS: 21
Citation - Scopus: 22
Quantitative Determination of H2o2 for Detection of Alanine Aminotransferase Using Thin Film Electrodes
(Academic Press Inc Elsevier Science, 2020) Saygili, Ecem; Orakci, Beyza; Koprulu, Melisa; Demirhan, Alper; Ilhan-Ayisigi, Esra; Kilic, Yalin; Yesil-Celiktas, Ozlem
The abnormal concentrations or absence of biomolecules (e.g., proteins) in blood can further be used in diagnosis of a particular pathology at an early stage. Current studies are intensely focusing on the analysis of interaction and detection of biomolecules via point-of-care systems (POCs), allowing miniaturized and parallelized reactions, simultaneously. Recent developments have shown that the collaboration of electrochemical sensing techniques and POCs to overcome challenging problems in health-care settings provides new approaches in diagnosis and treatment of diseases. The aim of this study was to adapt the alanine aminotransferase (ALT) enzyme to the platinum (Pt) thin film electrode system and quantitatively determine the enzyme levels via enzymatically generated H2O2 with differential pulse voltammetry (DPV). A simple potentiostat architecture with expanded sweep range utilizing dual LMP91000 devices was developed and adapted to the needs of the biosensor. In order to calibrate the system, known concentrations of H2O2 were also tested. Moreover, signals associated with the other electroactive species coming from the ALT reaction were eliminated. Resulted potential range has been achieved between +500 mV and + 900 mV and the linear range was found to be 0.05 M-0.5 M for H2O2, whereas 5 UL-1 to 120 UL-1 for ALT enzyme.
Citation - WoS: 17
Citation - Scopus: 20
Scalable Video Encryption of H.264 Svc Codec
(Academic Press Inc Elsevier Science, 2011) Algın, Gül Boztok; Tunalı, Turhan
A new algorithm for encrypting H.264 SVC (Scalable Video Codec) video data is developed. Security requirements of encoded video are examined together with constraints arising from structural properties of the SVC software. Performance analysis of the new algorithm is reported and its strength against cryptanalysis attacks is discussed. It has been demonstrated that the new algorithm has almost no overhead with low level encryption and acceptable overhead for high level encryption that leads to totally unperceivable video. (C) 2011 Elsevier Inc. All rights reserved.