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Energy-Efficient Secure Communication for Ios Aided Cfmmimo Network
No full textIn this article, we investigate the security energy efficiency (SEE) of intelligent omni-surface (IOS) aided cell-free massive MIMO (CFMMIMO) networks. Firstly, we provide a SEE maximization design for the IOS-assisted CFMMIMO network. To address the formulated non-convex, multivariate problem, in particular, we first decouple the problem into two sub-problems, and design corresponding low-complexity algorithms for each sub-problem, including the joint optimization algorithm of the access point (AP) transmission beamforming and artificial noise covariance matrix based on semi-smooth Newton method (SSNM) as well as the joint optimization algorithm of IOS reflection-transmission phase shift matrix based on Riemannian product manifolds-conjugate gradient method (RPM-CG). The two subproblems are then iterated iteratively using the Block Coordinate Descent (BCD) algorithm to obtain the maximum SEE of the IOS-assisted CFMMIMO network. Simulation results show that the proposed algorithm outperforms the five baseline schemes in terms of SEE.Fundamental Research Funds for the Central Universities [2042024kf1006]; National Key R&D Program of China [2023YFE0206600]This work was supported in part by the Fundamental Research Funds for the Central Universities with no. 2042024kf1006, and in part by the National Key R&D Program of China under Grant 2023YFE0206600. Y. Hu is the corresponding author.Conference Proceedings Citation Index - Scienc
Algorithm for Key Transparency With Transparent Logs
No full textBackground: Cryptography plays a crucial role in securing digital communications and data storage. This study evaluates the Transparent Key Management Algorithm utilizing Merkle trees, focusing on its performance and security effectiveness in cryptographic key handling. Methods: The research employs simulated experiments to systematically measure and analyze key operational metrics such as insertion and verification times. Synthetic datasets are used to mimic diverse operational conditions, ensuring rigorous evaluation under varying workloads and security threats. Implementation is carried out using R programming, integrating cryptographic functions and Merkle tree structures for integrity verification. Results: Performance analysis reveals efficient insertion and verification times under normal conditions, essential for operational workflows. Security evaluations demonstrate the algorithm's robustness against tampering, with approximately 95% of keys verified successfully and effective detection of unauthorized modifications. Simulated attack scenarios underscore its resilience in mitigating security threats. Conclusions: The Transparent Key Management Algorithm, enhanced by Merkle trees and cryptographic hashing techniques, proves effective in ensuring data integrity, security, and operational efficiency. Recommendations include continuous monitoring and adaptive algorithms to bolster resilience against evolving cybersecurity challenges, promoting trust and reliability in cryptographic operations. Copyright: © 2024 Mollakuqe E et al.European Union’s Framework Programme for Research & Innovation; European Cooperation in Science and Technology, COST, (CA 19130); European Cooperation in Science and Technology, COS
Repetitive Rolling of Triptycene-Based Molecules on Cu Surfaces
No full textDurukanoglu, Sondan/0000-0001-6008-8321; Uysal, Mehmet Tuna/0000-0002-9460-8804The metal surface-supported rotation of artificial molecular structures is technologically important for developing molecular-level devices. The key factors leading to the practical applications of these molecular machines on metal surfaces are the atomic-scale control of the rotation and the counterbalance of the temperature-driven instability of the molecules. In this work, we present a means by which triptycene-based molecular wheels can roll repetitively on a metal surface. Our results show that regularly stepped surfaces are the perfect candidate not only for stabilizing the molecule on the metal surface but also for providing the pivot points needed for repetitive vertical rotation of the molecule at higher temperatures. In addition to the geometrical compatibility of the substrate and the molecule, intermittent application of the external electric field is needed for rolling the molecule on a metal-stepped surface in a controllable manner.Scientific and Technological Research Council of Turkiye-TUBITAK [114F159]This work was supported by the Scientific and Technological Research Council of Turkiye-TUBITAK under Grant No. 114F159.Science Citation Index Expande
Data-Driven Methods for Optimal Setting of Legacy Control Devices in Distribution Grids
No full textThis study presents machine learning-based dispatch strategies for legacy voltage regulation devices, i.e., onload tap changers (OLTCs), step-voltage regulators (SVRs), and switched-capacitors (SCs) in modern distribution networks. The proposed approach utilizes k-nearest neighbor (KNN), random forest (RF), and neural networks (NN) to map nodal net active and reactive injections to the optimal legacy controls and resulting voltage magnitudes. To implement these strategies, first, an efficient optimal power flow (OPF) is formulated as a mixed-integer linear program that obtains optimal decisions of tap positions for OLTCs, SVRs, and on/off status of SCs. Then, training and testing datasets are generated by solving the OPF model for daily horizons with 1-hr resolution for varying loading and photovoltaic (PV) generation profile. Case studies on the 33-node feeder demonstrate high-accuracy mapping between the input feature and the output vector, which is promising for integrated Volt/VAr control schemes. © 2024 IEEE
Dynamic Narratives of Migration: The Changing Urban Experiences of Georgian Migrant Women in Turkey
No full textBu çalışma, Türkiye'de yaşayan Gürcü göçmen kadınların göç deneyimi sonrası gündelik yaşam pratiklerinde ve kentsel deneyimlerindeki değişimi tespit etmeyi amaçlamaktadır. Ayrıca, mutlak bir arayış olarak göçün kadınların güçlenmesi ve özerkliği üzerindeki etkisini açığa çıkarmayı hedefler. Kent odaklı nitel bir araştırma olarak kurgulanan bu tez, etnografiden esinlenerek feminist bir perspektif ışığında Sovyetler Birliği'nin dağılmasıyla birlikte ülkesinden göç eden kadınların hikayesine odaklanmaktadır. Bu özgün deneyimleri açığa çıkarabilmek adına Türkiye'nin farklı bölgelerinde yaşayan 12 göçmen kadınla görüşmeler gerçekleştirilmiştir. Yaşları 22 ile 61 arasında değişen odak grubu, farklı eğitim düzeyindeki kadınlardan oluşmaktadır. Bu görüşmeler sayesinde, göç deneyiminin kırılma noktaları, kadınların yeniden kurdukları gündelik yaşamda karşılaştıkları zorluklar ve bunun için kullandıkları başa çıkma mekanizmaları, kentsel yaşama adaptasyon süreçleri ve ev kurma tecrübeleri gibi konular mercek altına alınmıştır. Aynı zamanda, bu araştırmayı akademik ve kişisel açıdan derinleştirmek için 2022 yılı temmuz ve aralık aylarında Gürcistan'da saha ziyaretleri gerçekleştirilmiştir. Katılımcı gözlem yöntemi esas alınarak kadınların göç öncesi olası gündelik yaşam dinamikleri yakından incelenmiştir. Çalışma sorularını cevaplandırmak elde edilen tüm nitel veriler analiz edilerek beş alt başlık oluşturulmuştur. Sonuç olarak bu tez, göçün kadınların günlük rutinlerini nasıl şekillendirdiğini araştırarak insanlar, mekanlar ve kişisel anlatılar arasındaki etkileşimin anlaşılmasına katkıda bulunmaktadır. Yapılan görüşmeler, yaş, meslek ve göç nedenleri gibi faktörlerin etkisi altında, deneyimler arasındaki nüansları göstererek, bu ilişkilerin bireysel doğasını vurgulamakta ve daha fazla etnografik keşif için bulgular önermektedir. Anahtar Sözcükler: Göç, Gürcistan, Kent, Göçün Feminizasyonu, Göçmen, Kadın, Gündelik Hayat, Mekân, Ev, SınırThis thesis delves into the ever-changing daily life practices and urban experiences of Georgian migrant women in Turkey following their migration. Additionally, it seeks to investigate the impact of migration on women's empowerment and autonomy. Employing urban-focused qualitative research inspired by ethnography with feminist perspectives, this empirical study examines the experiences of women who migrated from Georgia in the 1990s following the dissolution of the Soviet Union. Twelve women, aged 22 to 61 and living in various parts of Turkey, were interviewed in-depth to uncover their migration journey, the challenges in rebuilding their lives, their coping strategies, their adjustment to urban settings, and their efforts to create a sense of home. Moreover, field visits to Georgia in July and December 2022, particularly in Tbilisi and Batumi, provided local insights into the daily lives of women in their native land through participant observation. Five subheadings were created by combining qualitative data from field observations and interviews to analyze the variations in women's post-migration urban experiences. The final chapter adopts a poetic and spatial standpoint on home, exploring how women uniquely and innovatively forge their own sense of belonging and domestic space. In conclusion, this thesis explores how women's transitions between locations shape their daily routines, thereby contributing to our understanding of the interplay between people, places, and personal narratives. Through interviews with migrants from diverse backgrounds, it demonstrates the nuanced differences in experiences influenced by factors such as age, profession, and reasons for relocation, thus highlighting the individualized nature of these relationships and suggesting avenues for further ethnographic exploration. Keywords: Migration, Georgia, Urban, Feminization of Migration, Migrant, Woman, Daily Life, Space, Home, Borde
The Multicolored Graph Realization Problem
No full textSerna Iglesias, Maria Jose/0000-0001-9729-8648; Diner, Oznur Yasar/0000-0002-9271-2691; Serra, Oriol/0000-0001-8561-4631We introduce the multicolored graph realization problem (MGR). The input to this problem is a colored graph ( G , phi ), i.e., a graph G together with a coloring phi on its vertices. We associate each colored graph ( G , phi ) with a cluster graph ( G phi ) in which, after collapsing all vertices with the same color to a node, we remove multiple edges and self -loops. A set of vertices S is multicolored when S has exactly one vertex from each color class. The MGR problem is to decide whether there is a multicolored set S so that, after identifying each vertex in S with its color class, G [ S ] coincides with G phi . The MGR problem is related to the well-known class of generalized network problems, most of which are NP -hard, like the generalized Minimum Spanning Tree problem. The MGR is a generalization of the multicolored clique problem, which is known to be W [ 1 ] -hard when parameterized by the number of colors. Thus, MGR remains W [ 1 ] - hard, when parameterized by the size of the cluster graph. These results imply that the MGR problem is W [ 1 ] -hard when parameterized by any graph parameter on G phi , among which lies treewidth. Consequently, we look at the instances of the problem in which both the number of color classes and the treewidth of G phi are unbounded. We consider three natural such graph classes: chordal graphs, convex bipartite graphs and 2 -dimensional grid graphs. We show that MGR is NP -complete when G phi is either chordal, biconvex bipartite, complete bipartite or a 2 -dimensional grid. Our reductions show that the problem remains hard even when the maximum number of vertices in a color class is 3. In the case of the grid, the hardness holds even for graphs with bounded degree. We provide a complexity dichotomy with respect to cluster size. (c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Spanish Agencia Estatal de Investigacion [PID2020-113082GB-I00, PID2020-112581GB-C21]; AGAUR [2017-SGR-786]; Scientific and Technological Research Council [BIDEB 2219-1059B191802095]; Kadir Has University [2018-BAP-08]We thank the anonymous referees for their careful reading and helpful suggestions. J. Diaz and M. Serna are partially supported by funds from the Spanish Agencia Estatal de Investigacion under grant PID2020-112581GB-C21 (MOTION) , and from AGAUR under grant 2017-SGR-786 (ALBCOM) . OE. Y. Diner is partially supported by the Scientific and Technological Research Council Tuebitak under project BIDEB 2219-1059B191802095 and by Kadir Has University under project 2018-BAP-08. O. Serra is supported by the Spanish Agencia Estatal de Investigacion under grant PID2020-113082GB-I00.Science Citation Index Expande
Sustainability performance assessment of freight transportation modes using an integrated decision-making framework based on m-generalized q-neutrosophic sets
No full textTirkolaee, Erfan Babaee/0000-0003-1664-9210; Aytekin, Ahmet/0000-0002-1536-7097The freight transport industry is one of the primary sectors responsible for excessive energy consumption and greenhouse gas emissions. Restructuring international and domestic freight transport chains based on sustainability and green transportation is critical for practitioners and policymakers to reduce pressure on the logistics and transportation industries. This study aims to develop a mathematical model for selecting the most appropriate transportation type, and accordingly, the optimal route in transportation operations to improve the sustainability performance of the freight transportation industry. Therefore, the main goal is to choose the most suitable route and transportation type which contributes to create a more eco-friendly and sustainable transportation system. For this purpose, Neutrosophic Number-based Delphi (NN-Delphi), m-Generalized q-Neutrosophic Sets (mGqNSs)-based Stepwise Weight Assessment Ratio Analysis (MGqNS-SWARA) and mGqNSs-based Additive Ratio Assessment (mGqNS-ARAS) are developed and implemented to set the influential criteria, compute the weights of these criteria, and identify the sustainability performance of the freight mode variants, respectively. According to the final results, "Cargo security" and "Accident rates" are the most important criteria with a relative importance score of 0.0237, contributing to the sustainability of load transport modes. Moreover, "Maritime Transport Mode" is identified as the most sustainable transportation type with a relative importance score of 0.7895. Finally, it is revealed that there is a positive relationship between maritime transport and sustainability
The Role of Hydrogen in the Energy Mix: a Scenario Analysis for Turkey Using Osemosys
No full textThe urgent need to tackle climate change drives the research on new technologies to help the transition of energy systems. Hydrogen is under significant consideration by many countries as a means to reach zero-carbon goals. Turkey has also started to develop hydrogen projects. In this study, the role of hydrogen in Turkey's energy system is assessed through energy modeling using the cost optimization analytical tool, Open Source Energy Modelling System (OSeMOSYS). The potential effects of hydrogen blending into the natural gas network in the Turkish energy system have been displayed by scenario development. The hydrogen is produced via electrolysis using renewable electricity. As a result, by using hydrogen, a significant reduction in carbon dioxide emissions was observed; however, the accumulated capital investment value increased. Furthermore, it was shown that hydrogen has the potential to reduce Turkey's energy import dependency by decreasing natural gas demand.Science Citation Index Expande
Cycle-Star Motifs: Network Response To Link Modifications
No full textEroglu, Deniz/0000-0001-6725-6949Understanding efficient modifications to improve network functionality is a fundamental problem of scientific and industrial interest. We study the response of network dynamics against link modifications on a weakly connected directed graph consisting of two strongly connected components: an undirected star and an undirected cycle. We assume that there are directed edges starting from the cycle and ending at the star (master-slave formalism). We modify the graph by adding directed edges of arbitrarily large weights starting from the star and ending at the cycle (opposite direction of the cutset). We provide criteria (based on the sizes of the star and cycle, the coupling structure, and the weights of cutset and modification edges) that determine how the modification affects the spectral gap of the Laplacian matrix. We apply our approach to understand the modifications that either enhance or hinder synchronization in networks of chaotic Lorenz systems as well as R & ouml;ssler. Our results show that the hindrance of collective dynamics due to link additions is not atypical as previously anticipated by modification analysis and thus allows for better control of collective properties.TUBITAK; BAGEP Award of the Science Academy, Turkey; Newton Advanced Fellowship of the Royal Society [NAF \ \, 180236, 1709-16124]; FAPESP [2023/04294-0]; Leverhulme Trust [RPG-2021-072]; [119F125]SB, NK, and DE were supported by TUBITAK Grant No. 119F125. DE was supported by the BAGEP Award of the Science Academy, Turkey. TP was supported by a Newton Advanced Fellowship of the Royal Society NAF \ \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}\end{document} R1 \ \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}\end{document} 180236, by Serrapilheira Institute (Grant No. Serra- 1709-16124), and FAPESP (grant 2013/07375-0). SB and TP acknowledge the support of FAPESP (grant no. 2023/04294-0). SB acknowledges the support of Leverhulme Trust grant RPG-2021-072
Background Tv and Infant-Family Interactions: Insights From Home Observations
No full textUzundag, Berna/0000-0003-1192-691X; Koskulu-Sancar, Sumeyye/0000-0001-9221-2294Background television has been found to negatively impact children's language development and self-regulatory skills, possibly due to decreased parent-child interactions. Most of the research on the relationship between background TV and caregiver-child interactions has been conducted in laboratory settings. In the current study, we conducted home observations and investigated whether infants engage in fewer interactions with family members in homes where background TV is more prevalent. We observed 32 infants at the ages of 8, 10, and 18 months in their home environments, coding for dyadic interactions (e.g., parent talking to and/or engaging with the child), triadic interactions (e.g., parent and infant play with a toy together), and infants' individual activities. Our findings revealed that background TV was negatively associated with the time infants spent in triadic interactions, positively associated with time spent engaging in individual activities, and not significantly related to the time spent in dyadic interactions. Apart from the relationship between background TV and individual activity time at 8 months, these associations remained significant even after accounting for families' socioeconomic status. These findings imply a correlation between background TV exposure and caregiver-infant-object interactions, warranting a longitudinal analysis with larger sample sizes.Turkiye Bilimselve Teknolojik Arascedil;timath;rma Kurumu [113K006]Turkiye Bilimselve Teknolojik Ara & scedil;t & imath;rma Kurumu, Grant/Award Number:113K006