WoS İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12469/4465

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Citation - WoS: 2
Citation - Scopus: 1
3D self-assemble formation of molybdenum disulfide (MoS2)-doped polyacrylamide (PAAm) composite hydrogels
(Tubitak Scientific & Technological Research Council Turkey, 2022) Durmaz, Sumeyye; Yildiz, Ekrem; Uysal, Bengu Ozugur; Pekcan, Onder; Molecular Biology and Genetics; 05. Faculty of Engineering and Natural Sciences; 01. Kadir Has University
Polyacrylamide (PAAm), a renowned member of the hydrogel class, has many uses throughout a wide range of industrial processes, including water absorbed diapers, contact lenses, wastewater treatment, biomedical applications such as drug delivery vehicles and tissue engineering because of its physical stability, durability, flexibility easier shaping, and so on. PAAm also provides new functionalities after the incorporation of inorganic structures such as molybdenum disulfide (MoS2). During the copolymerization process, the transmittance of all samples reduced significantly after a particular time, referred to as the gel point. Microgels form a tree above the gel point as projected by Flory-Stockmayer classical theory. Because of microgels positioned at the junction points of the Cayley tree, the addition of MoS2 results in strong intramolecular crosslinking and looser composites. Moreover, fractal geometry provides a quantitative measure of randomness and thus permits characterization of random systems such as polymers. Fractal dimension of these polymer composites is calculated from power-law-dependent scattered intensity. It was also confirmed that a hydrogel rapidly formed within a few seconds, indicating a 3D network formation inside the gel. These materials may have a great potential for application in wearable and implantable electronics due to this highly desired 3D self-assemble feature.
Citation - WoS: 1
Citation - Scopus: 1
Accelerated Trends in Tourism Marketing and Tourist Behaviour
(Routledge, 2023) Kozak, Metin; Kozak, Metin; Advertising; 04. Faculty of Communication; 01. Kadir Has University
[No Abstract Available]
Citation - WoS: 7
Citation - Scopus: 6
The acquisition and use of relative clauses in Turkish-learning children's conversational interactions: a cross-linguistic approach
(Cambridge University Press, 2019) Uzundağ, Berna A.; Küntay, Aylin C.; Psychology; 03. Faculty of Economics, Administrative and Social Sciences; 01. Kadir Has University
Using a cross-linguistic approach, we investigated Turkish-speaking children's acquisition and use of relative clauses (RCs) by examining longitudinal child-caregiver interactions and cross-sectional peer conversations. Longitudinal data were collected from 8 children between the ages of 8 and 36 months. Peer conversational corpus came from 78 children aged between 43 and 64 months. Children produced RCs later than in English (Diessel, 2004) and Mandarin (Chen & Shirai, 2015), and demonstrated increasing semantic and structural complexity with age. Despite the morphosyntactic difficulty of object RCs, and prior experimental findings showing a subject RC advantage, preschool-aged children produced object RCs, which were highly frequent in child-directed speech, as frequently as subject RCs. Object RCs in spontaneous speech were semantically less demanding (with pronominal subjects and inanimate head nouns) than the stimuli used in prior experiments. Results suggest that multiple factors such as input frequency and morphosyntactic and semantic difficulty affect the acquisition patterns.
Citation - WoS: 3
Citation - Scopus: 2
Adaptive Sampling Noise Mitigation Technique for Feedback-Based Quantum Algorithms
(Springer international Publishing Ag, 2024) Rahman, Salahuddin Abdul; Clausen, Henrik Glavind; Karabacak, Ozkan; Wisniewski, Rafal; Mechatronics Engineering; 05. Faculty of Engineering and Natural Sciences; 01. Kadir Has University
Inspired by Lyapunov control techniques for quantum systems, feedback-based quantum algorithms have recently been proposed as alternatives to variational quantum algorithms for solving quadratic unconstrained binary optimization problems. These algorithms update the circuit parameters layer-wise through feedback from measuring the qubits in the previous layer to estimate expectations of certain observables. Therefore, the number of samples directly affects the algorithm's performance and may even cause divergence. In this work, we propose an adaptive technique to mitigate the sampling noise by adopting a switching control law in the design of the feedback-based algorithm. The proposed technique can lead to better performance and convergence properties. We show the robustness of our technique against sampling noise through an application for the maximum clique problem.
Citation - WoS: 1
Citation - Scopus: 1
Age Classification by WGAN Brain MR Image Augmentation
(IEEE, 2024) Yaman, Batuhan; Yilmaz, Ozge Zeynep; Darici, Muazzez Buket; Ozmen, Atilla; Electrical-Electronics Engineering; 05. Faculty of Engineering and Natural Sciences; 01. Kadir Has University
Medical image augmentation plays a crucial role in enhancing the performance of Artificial Intelligence (AI) applications in medical sciences. Augmenting medical images is important for solving data scarcity, increasing data diversity, enhancing robustness and reliability of model and improving training and test results that can be done in medical sciences. In this work we show that Wasserstein Generative Adversarial Network with Gradient Penalty (WGAN-GP) can be used for increasing the performance of data classification. To achieve that, we have augmented healthy brain MR images by using WGAN and updated the dataset. The results give that when dataset augmented by WGAN-GP is used as input for CNN-based model to solve age classification problem, accuracy of this model increases to 98,37% from 95,14%. It can be concluded that the purposed WGAN-based brain MR image augmentation method enhances the performance of image classification.
Citation - WoS: 5
Citation - Scopus: 7
Alternative Credit Scoring and Classification Employing Machine Learning Techniques on a Big Data Platform
(Institute of Electrical and Electronics Engineers Inc., 2019) Hindistan, Yavuz Selim; Kiyakoğlu, Burhan Yasin; Rezaeinazhad, Arash Mohammadian; Korkmaz, Halil Ergun; Dağ, Hasan; Management Information Systems; 03. Faculty of Economics, Administrative and Social Sciences; 01. Kadir Has University
With the bloom of financial technology and innovations aiming to deliver a high standard of financial services, banks and credit service companies, along with other financial institutions, use the most recent technologies available in a variety of ways from addressing the information asymmetry, matching the needs of borrowers and lenders, to facilitating transactions using payment services. In the long list of FinTechs, one of the most attractive platforms is the Peer-to-Peer (P2P) lending which aims to bring the investors and borrowers hand in hand, leaving out the traditional intermediaries like banks. The main purpose of a financial institution as an intermediary is of controlling risk and P2P lending platforms innovate and use new ways of risk assessment. In the era of Big Data, using a diverse source of information from spending behaviors of customers, social media behavior, and geographic information along with traditional methods for credit scoring prove to have new insights for the proper and more accurate credit scoring. In this study, we investigate the machine learning techniques on big data platforms, analyzing the credit scoring methods. It has been concluded that on a HDFS (Hadoop Distributed File System) environment, Logistic Regression performs better than Decision Tree and Random Forest for credit scoring and classification considering performance metrics such as accuracy, precision and recall, and the overall run time of algorithms. Logistic Regression also performs better in time in a single node HDFS configuration compared to a non-HDFS configuration.
Citation - Scopus: 1
Analysis and Optimization of the Network Throughput in IEEE 802.15.13 based Visible Light Communication Networks
(IEEE, 2021) Bulbul, Yusuf; Elamassie, Mohammed; Baykas, Tuncer; Uysal, Murat; Electrical-Electronics Engineering; 05. Faculty of Engineering and Natural Sciences; 01. Kadir Has University
In line with the growing interest on visible light communication (VLC), IEEE has initiated standardization efforts on this emerging technology. In this work, we consider IEEE 802.15.13 Optical Wireless Personal Area Networks (OWPAN) standard draft. The underlying MAC protocol uses contention free and contention access periods. For a standard-compliant VLC network, we analyze the network load and propose an algorithm to improve the network throughput by proper selection of period lengths. Our suggested algorithm improves the network performance by at least 5% in the case of variable network traffic up to 15 active users.
Citation - WoS: 2
Citation - Scopus: 5
Analysis of deep learning based path loss prediction from satellite images
(IEEE, 2021) Alam, Muhammad Z.; Ates, Hasan F.; Baykas, Tuncer; Gunturk, Bahadir K.; Electrical-Electronics Engineering; 05. Faculty of Engineering and Natural Sciences; 01. Kadir Has University
Determining the channel model parameters of a wireless communication system, either by measurements or by running electromagnetic propagation simulations, is a time-consuming process. Any rapid deployment of network demands faster determination of at least major channel parameters. In this paper, we investigate the idea of using deep convolutional neural networks and satellite images for channel parameters (i.e., path loss exponent n and shadowing factor sigma) prediction in a cellular network with aerial base stations. Specifically, we investigate the performance dependency of the method on three different factors: height of the transmitter antenna, quantization levels of the channel parameters and architectural design of CNN. The results presented in this paper show a high prediction accuracy of the channel parameters in real-time.
Citation - WoS: 1
An analysis of social media content shared by right-wing extremist groups in the United States, the Great Britain and Australia
(Istanbul Univ, Fac Communication, 2023) Masalha, Oday; Bas, Ozen; New Media; 04. Faculty of Communication; 01. Kadir Has University
The extreme right movements have increasingly appeared on social media, especially on Twitter and Facebook, coinciding with the 2019 New Zealand attack, the 2019 El Paso incident, and Britain's exit from the European Union in 2020. This study examines the content and the form of extreme right-wing activities on Facebook and Twitter to promote their ideologies. A qualitative content analysis was conducted on posts shared by extreme-right groups on public Facebook and Twitter accounts in Great Britain, the United States and Australia. The sample spans from March 15, 2019 to February 5, 2020. The posts were coded according to a coding instrument developed based on the existing literature spreading extremist ideologies on social media. The coding instrument consisted of categories and subcategories such as 'the protection of western values', 'anti-LGBT activism', 'anti-feminism', 'anti-Islam', 'anti-immigrant sentiments', 'fostering the white race', and 'anti-elitist populism'. Findings suggest that the most prevalent extremist ideologies on Facebook and Twitter posts were 'anti-elitist populism' and 'the protection of western values'. Also, extremist groups heavily shared posts that combined texts and images to spread their ideologies on social media.
An Ant-Lion Optimization Based Approach to Solve Phase Balancing Problem in Distribution Networks
(IEEE, 2024) Yesilyurt, Gunnur; Ceylan, Oguzhan; Management Information Systems; 03. Faculty of Economics, Administrative and Social Sciences; 01. Kadir Has University
Phase unbalance is a significant issue for power distribution networks. It can lead to increased energy losses and voltage instability, undermining the electrical grid's reliability and efficiency. We propose an approach to minimize voltage unbalance through reactive power management from PV installations and the optimization of charging/discharging of energy storage devices utilizing a control algorithm based on Ant-Lion Optimizer. We tested the approach on the IEEE 123-Bus Test System, incorporating PV generations by daily simulations. From the results, the combined operation of reactive power support from PVs and Storage Units with the help of the ALO algorithm offers a promising solution to the phase unbalance problem.
Citation - WoS: 79
Citation - Scopus: 95
The association of the severity of obstructive sleep apnea with plasma leptin levels
(Amer Medical Assoc., 2003) Öztürk, Levent; Ünal, Murat; Tamer, Lülüfer; Çelikoğlu, Firuz; 01. Kadir Has University
Objective: To examine whether circulating leptin levels correlate with the severity of disease in patients with obstructive sleep apnea. Design: Prospective nonrandomized study. Setting: Referral sleep laboratory for patients with sleep-disordered breathing and biochemistry laboratory. Patients: Thirty-two subjects (mean+/-SD age 47+/-12 years) who were referred for suspected sleep apnea underwent an overnight sleep study and fasting morning venous blood sampling. Patients were divided into 3 groups with respect to apnea-hypopnea index: (1) severe sleep apnea (n=8) apnea-hypopnea index greater than 20
Citation - WoS: 2
Attentional Control Scale-Turkish Version: Psychometric Qualities, Factor Structure and Its Comparison with Behavioral Measures of Executive Attention
(ODTU-AYNA Klinik Psikoloji Destek Unitesi, 2024) Altan-Atalay, Ayse; Cinli, Dilem; Aksungur, Sebla Umay; Turkakin, Esin; Psychology; 03. Faculty of Economics, Administrative and Social Sciences; 01. Kadir Has University
Attentional control refers to the capacity to voluntarily control attentional resources in a flexible manner. Attentional control was reported to play a fundamental role in self-regulation, emotion regulation, delay of gratification, and psychological distress. The Attentional Control Scale (ACS) was developed to measure perceived attentional control based on shifting and focusing dimensions. The present studies aimed to adapt the Turkish version of ACS and asses its psychometric characteristics. Study 1 aimed to explore the psychometric qualities of the Turkish version with a group of Turkish individuals (N = 428, 306 women) between the ages of 18 and 68 and supported the two-factor model of ACS consisting of 17 items in total. The results supported that shifting, focusing, and total ACS showed adequate internal consistency, test-retest reliability, and convergent validity evidence based on its significant correlations with measures of anxiety, depression, and repetitive negative thinking, signifying its proper psychometric characteristics. In Study 2 (N = 97, 65 women), the association of ACS with behavioral attentional control measures was examined, and non-significant associations between self-report and behavioral measures of attentional control were denoted. These findings signified that rather than indicating the individual's actual attentional control capacity, ACS assessed how the individual perceives their own attention control capacities. Taken together, the results suggest that the Turkish form of ACS is a valid and reliable scale that can be used to assess perceived attentional control capacity based on shifting and focusing domains, particularly in the research setting.
Citation - WoS: 10
Citation - Scopus: 11
Automatic Adaptation of Hypermutation Rates for Multimodal Optimisation
(Assoc Computing Machinery, 2021) Corus, Dogan; Oliveto, Pietro S.; Yazdani, Donya; Computer Engineering; 05. Faculty of Engineering and Natural Sciences; 01. Kadir Has University
Previous work has shown that in Artificial Immune Systems (AIS) the best static mutation rates to escape local optima with the ageing operator are far from the optimal ones to do so via large hypermutations and vice-versa. In this paper we propose an AIS that automatically adapts the mutation rate during the run to make good use of both operators. We perform rigorous time complexity analyses for standard multimodal benchmark functions with significant characteristics and prove that our proposed algorithm can learn to adapt the mutation rate appropriately such that both ageing and hypermutation are effective when they are most useful for escaping local optima. In particular, the algorithm provably adapts the mutation rate such that it is efficient for the problems where either operator has been proven to be effective in the literature.
Beyond the Disaster: Vulnerability of Governance in the Turkey-Syria Earthquake
(Palgrave Macmillan, 2024) Yilmaz, Elif Ebru; Tomaka, Deniz Halman; 01. Kadir Has University; Core Program; 07. Core Program
Citation - WoS: 5
Citation - Scopus: 5
Block Elimination Distance
(Springer Japan Kk, 2022) Diner, Oznur Yasar; Giannopoulou, Archontia C.; Stamoulis, Giannos; Thilikos, Dimitrios M.; Computer Engineering; 05. Faculty of Engineering and Natural Sciences; 01. Kadir Has University
We introduce the parameter of block elimination distance as a measure of how close a graph is to some particular graph class. Formally, given a graph class g, the class B(G) contains all graphs whose blocks belong to G and the class A(G) contains all graphs where the removal of a vertex creates a graph in G. Given a hereditary graph class G, we recursively define G((k)) so that G((0)) = B(G) and, if k >= 1 G((k)) B(A(G((k-1))) ) N We show that, for every nontrivial hereditary class g, the problem of deciding whether G is an element of G((k)) is NP-complete. We focus on the case where G is minor-closed and we study the minor obstruction set of G((k)) i.e., the minor-minimal graphs not in G((k)). We prove that the size of the obstructions of G((k)) is upper bounded by some explicit function ofk and the maximum size of a minor obstruction of G. This implies that the problem of deciding whether G is an element of G((k)) is constructively fixed parameter tractable, when parameterized by k. Finally, we give two graph operations that generate members of G((k)) from members of G((k -1)) and we prove that this set of operations is complete for the class O of outerplanar graphs.Please check and confirm if the authors Given and Family names have been correctly identified for author znur YaYar Diner. All authors names have been identified conectly. Please confirm if the corresponding author is correctly identified. Amend if necessary.This is correct
Block Elimination Distance
(Springer international Publishing Ag, 2021) Diner, Oznur Yasar; Giannopoulou, Archontia C.; Stamoulis, Giannos; Thilikos, Dimitrios M.; Computer Engineering; 05. Faculty of Engineering and Natural Sciences; 01. Kadir Has University
We introduce the parameter of block elimination distance as a measure of how close a graph is to some particular graph class. Formally, given a graph class G, the class B(G) contains all graphs whose blocks belong to G and the class A(G) contains all graphs where the removal of a vertex creates a graph in G. Given a hereditary graph class G, we recursively define G((k)) so that G((0)) = B(G) and, if k >= 1, G((k)) = B(A(G((k-1)))). The block elimination distance of a graph G to a graph class G is the minimum k such that G is an element of G((k)) and can be seen as an analog of the elimination distance parameter, defined in [J. Bulian & A. Dawar. Algorithmica, 75(2):363-382, 2016], with the difference that connectivity is now replaced by biconnectivity. We show that, for every non-trivial hereditary class G, the problem of deciding whether G. G(k) is NPcomplete. We focus on the case where G is minor-closed and we study the minor obstruction set of G((k)) i.e., the minor-minimal graphs not in G((k)). We prove that the size of the obstructions of G((k)) is upper bounded by some explicit function of k and the maximum size of a minor obstruction of G. This implies that the problem of deciding whether G is an element of G((k)) is constructively fixed parameter tractable, when parameterized by k. Our results are based on a structural characterization of the obstructions of B(G), relatively to the obstructions of G. Finally, we give two graph operations that generate members of G((k)) from members of G((k-1)) and we prove that this set of operations is complete for the class O of outerplanar graphs. This yields the identification of all members O boolean AND G((k)), for every k is an element of N and every non-trivial minor-closed graph class G.
Çağının Mimarlık Ortamına Katkılarıyla Diyarbakır Artuklu Sultanı Nâsırüddin Melik Salih Mahmud (1200-1222)
(Istanbul Univ, Research Inst. Turkology, Dept Art History, 2025) Alper, Mehmet; Architecture; 06. Faculty of Art and Design; 01. Kadir Has University
Nasir al-Din Mahmud (1200-1222 AD) served as the sultan of the Hasankeyf and Diyarbakir branches of the Artuqid Principality, which governed three branches acrossthe Diyarbakir and Mardin Regions from 1102 to1409.The building inscriptions indicate that N & acirc;s & imath;r & uuml;ddin Melik Salih Mahmud, who prioritized construction projects during his reign, played a significant role as both the constructor and architect of significant structures of his time, transcending his political role. The Yedi Karde & scedil;Bastion (1208-1209 AD) and Devege & ccedil;idi Bridge are two architectural works stated with the words designer (tersim) in their inscriptions that they were built in line with the plans of Nasir al-Din Mahmud. Even though it is not mentioned in the construction inscriptions, it is accepted that the Ulu Beden Bastion and Artuqid Palace were built with his design, considering their architectural features and decorations with a double-headed eagle coat of arms, the symbol of Nasir al-Din Mahmud's period. This study, which examines the construction activities during the reign of Artuqid Sultan Nasir al-Din Mahmud, who reigned between 1200 and 1222, examines the structures built in Diyarbakir during this period. The information obtained through literature studies was evaluated together with the findings obtained during the restoration work carried out within the scope of the "Diyarbakir Walls Protection Project", and the period of Nasir al-Din Mahmud was examined from multiple perspectives, and the patron-architect relationship and the contribution of the ruler to the design process were attempted to be revealed. In addition, itwas aimed to date the courtyard section, which is an annex of the Artuqid Period of St. George Church, which is accepted as the oldest church in Diyarbakir and dates back to the 3rd century AD, and to clarify its function during the period it was built.
Citation - WoS: 3
Citation - Scopus: 3
Challenges of Teaching in a Different Culture: An Auto-Ethnographic Study
(Cognizant Communication Corp, 2021) Kozak, Metin; Advertising; 04. Faculty of Communication; 01. Kadir Has University
Teaching in a different culture and environment is always a challenging issue. This may last from a few months to a few years, depending on the consequences of personal characteristics and environmental situations. Based on a personal experience, this article investigates the possible cultural differences between the lecturer and students in a teaching environment and understanding how the student perceptions may gradually change and the student -lecturer interaction may evolve until the semester ends. In a methodological way, the conclusions were drawn out of a mixed-method approach that is composed of a personal observation of the lecturer (etic), and expressions, both verbal and written, and memories of other persons (students) within the same class (emit). In lights of Hofstede's cultural dimensions, the study addresses a list of practical implications as the lessons learned-presumably the best way to cope with the challenges of teaching in a different culture.
Citation - WoS: 1
Citation - Scopus: 1
Channel Estimation and Physical Layer Security in Optical MIMO-OFDM based LED Index Modulation
(IEEE, 2023) Okumus, F. Batuhan; Panayırcı, Erdal; Khalighi, Mohammad Ali; Electrical-Electronics Engineering; 05. Faculty of Engineering and Natural Sciences; 01. Kadir Has University
In this paper, we propose a new and low-complexity channel estimation algorithm for the generalized LED index modulation (GLIM), recently proposed for visible-light communication systems based on multi-input multi-output (MIMO) and orthogonal frequency-division multiplexing (OFDM). For this scheme, denoted by GLIM-OFDM, we investigate the bit-error rate (BER), the mean-square error (MSE) of channel estimation, as well as the Cramer-Rao bound on the latter. Furthermore, we present a novel physical layer security (PLS) technique for the GLIM-OFDM scheme using precoding at the transmitter assuming it has the channel state information (CSI) between the LEDs and a legitimate user, but no knowledge of the CSI corresponding to eavesdroppers. The efficiency of the proposed PLS technique is demonstrated through numerical results.
Citation - WoS: 2
Citation - Scopus: 3
Channel Estimation Using Optical MIMO OFDM Based LED Index Modulation
(IEEE, 2021) Okumus, Furkan Batuhan; Panayırcı, Erdal; Electrical-Electronics Engineering; 05. Faculty of Engineering and Natural Sciences; 01. Kadir Has University
In this paper, a new MIMO channel estimation technique is proposed for generalized LED index modulation (GLIM-OFDM) developed for multi-input multi-output (MIMO) orthogonal frequency division multiplexing (OFDM) based VLC systems. The mean square error (MSE) of the channel estimation algorithm, the bit error rate (BER) and the Cramer-Rao (CR) lower-bound of the system were obtained analytically and the performance of the algorithm according to the signal-to-noise ratio was investigated by computer simulations. From the obtained MSE, BER and CR curves it is concluded that the MSE performance of the proposed channel estimation algorithm is very high and the BER performance of the system obtained with the estimated channel information is very close to the BER performance in the case of perfect knowledge of the channel.

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