Search

Fifteen percent of couples of reproductive age suffer frominfertility globally and the burden of infertility disproportionately impacts residents of developing countries. Assisted reproductive technologies (ARTs), including in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), have been successful in overcoming various reasons for infertility including borderline and severe male factor infertility which consists of 20%-30% of all infertile cases. Approximately half of male infertility cases stem from suboptimal sperm parameters. Therefore, healthy/normal sperm enrichment and sorting remains crucial in advancing reproductive medicine. Microfluidic technologies have emerged as promising tools to develop in- home rapid fertility tests and point-of-care (POC) diagnostic tools. Here, we review advancements in fabrication methods for paper-based-microfluidic devices and their emerging fertility testing applications assessing sperm concentration, sperm motility, sperm DNA analysis, and other sperm functionalities, and provide a glimpse into future directions for paper-based fertility microfluidic systems., Scientific and Technological Research Council of Turkey (TÜBİTAK); 2232 International Fellowship for Outstanding Researchers Award; European Union (EU); Horizon 2020; Marie Sklodowska-Curie Individual Fellowship; Royal Academy Newton-Katip Çelebi Transforming Systems Through Partnership Award; Alexander von Humboldt Research Fellowship for Experienced Researchers; Science Academy Young Scientist Awards Program (BAGEP); Outstanding Young Scientists Awards (GEBİP); Bilim Kahramanlari Dernegi Young Scientist Award

This paper addresses a humanitarian logistics problem connected with the Syrian refugee crisis. The ongoing conflict in Syria has caused displacement of millions of people. Cash-based interventions play an important role in aiding people in the post-crisis period to enhance their well-being in the medium and longer term. The paper presents a study on how to design a network of administrative facilities to support the roll-out of cash-based interventions. The resulting multi-level network consists of a central registration facility, local temporary facilities, mobile facilities and vehicles for door-to-door visits. The goal is to reach the maximum number of eligible beneficiaries within a specified time period while minimizing logistics costs, subject to a limit on total security risk exposure. A mixed integer programming model is formulated to optimize the inter-related facility location and routing decisions under multiple objectives. The authors develop a hierarchical multi-objective metaheuristic algorithm to obtain efficient solutions. An application of the model and the solution algorithm to real data from a region in the southeast of Turkey is presented, with associated managerial insights., ESRC; Scientific and Technological Research Council of Turkey (TÜBİTAK)

Incorporating concerns of sustainability and circularity into design practice is undoubtedly important for both design research and education. There is a need to equip novice designers with the skills to facilitate a sustainability-focused future, whilst also collaborating with industry to implement these concerns into contemporary design practices. On the one hand, SMMEs and small teams in other sectors (i.e. public) lack the resources and time to improve their knowledge, to explore alternative ways of conducting business and to transform their design practices. Contrarily, novice designers (i.e. design students) can access state-of-the-art knowledge on sustainability and experiment with sustainable design practices throughout their education, yet they lack insights into market realities around implementation. Similarly, design researchers and educators are on the fore-front of developing sustainability-focused design methodology through research, but they often lack exposure to the industry. If the parties were all to work together, however, the sharing of resources, knowledge and experiences become valuable commodities in creating more sustainable design practices. This paper outlines an on-campus Design for Circular Economy and Sustainability training programme where industry worked with interns and academics to address real-world challenges. The project forms a part of a larger EU collaboration. The programme aimed to create a co-learning environment for novice designers, industry partners and design researcher/educators. Here all stakeholders could exchange their knowledge and insights and learn from each other to explore and experiment with practically implementing sustainability in real-world contexts. This paper briefly introduces the development of the programme and explores how and what co-learning occurred for the different stakeholders. Finally, the paper discusses how the outcomes of this programme subsequently affected the practices of industry partne, European Commission (EC); European Union (EU); Erasmus thorn Programme of the European Union; Circular Design: Learning for Innovative Design for Sustainability (L4IDS) Knowledge Alliance Project

This paper reports on the in-situ synthesis, optimization, characterization and cytotoxicity tests of multi-layer graphene (MLG) encapsulated Fe/Fe2O3 nanoparticles (Fe/Fe2O3@C core-shell nanostructures) by spray drying-assisted chemical vapor deposition (CVD) using iron-nitrate/silica-based precursors. The influences of CVD reaction temperature, holding time, CH4/H2 gas flows and pressure on the synthesis of MLG encapsulated Fe/Fe2O3 nanoparticles were investigated. CVD-synthesized powders were purified using acid leaching to remove residual silica and probable uncoated Fe/Fe-oxide phases. XRD analyses revealed the presence of FCC (Fe,C), BCC Fe, graphite/graphene and trace amount of Fe2O3 phases. Raman spectra confirmed the existence of MLG shells. TEM indicated that MLG (from at least 3 to maximum of 35 layers) wrapped around the metallic cores ranged be-tween 4 and 85 nm. Purification of nanoparticles did not degrade, dissolve or create discontinuity on the MLG structure. VSM measurements showed that nanoparticles obtained from the optimized conditions (900 ?, 100 ml/min CH4/H2, 50 mbar) had a soft ferromagnetic behavior with low saturation magnetization (-85 emu/g) and coercivity (-552 Oe) values. Optimized MLG encapsulated Fe/Fe2O3 nanoparticles were successfully suspended in water using a poly(acrylic acid) coating. Aqueous MLG encapsulated Fe/Fe2O3 nanoparticles were cytocompatible below 100 mg/ml at short incubation times, and showed the potential to be used in biomedical applications. (c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)., Scientific and Technological Research Council of Turkey (TÜBİTAK); Istanbul Technical University Scientific Research Projects (ITU-BAP)

The cyclotomic p-adic multi-zeta values are the p-adic periods of pi(uni)(1)(G(m) \ mu M,(.)), the unipotent fundamental group of the multiplicative group minus the M-th roots of unity. In this paper, we compute the cyclotomic p-adic multi-zeta values at all depths. This paper generalizes the results in [9] and [10]. Since the main result gives quite explicit formulas we expect it to be useful in proving non-vanishing and transcendence results for these p-adic periods and also, through the use of p-adic Hodge theory, in proving non-triviality results for the corresponding p-adic Galois representations., Alexander von Humboldt Foundation

This paper aims at understanding the adhesion mechanics of a pressure-controlled adhesive thin elastomeric membrane for soft robotic gripping on non-planar, curved surfaces. The adhesive elastic membrane is lined with gecko-inspired microfiber arrays and can be inflated or deflated by controlled internal air pressure. Previous studies with the soft robotic grippers using dry adhesives showed repeatable adhesion and transfer printing of various non-planar objects with high reliability. In this study, we perform experimental characterization and theoretical analysis to better understand the influence of size and shape of the adhering curved objects on the range of internal air pressures as well as the force profile. In addition, decrease in the internal air pressure results in an increased pull-off force associated with a change in the range of gripper retraction for pulling off the membrane on various curved surfaces. An approximate analytical model dealing with the complex boundary conditions presented in this paper can provide quantitative estimates of pull-off forces for a wide variety of surface curvatures and internal air pressures, as well as qualitative understanding of how force profiles change under moderate pressure differentials., Max Planck Society

Background: the Syrian crisis, which started in March 2011, has resulted in the displacement of 6.3 million refugees predominantly to neighboring countries in addition to the internal displacement of 6.2 million people. Turkey is the country hosting the largest number of refugees in the world with 3.6 million Syrian refugees 46 % of which are under 18 years old. Objective: the purpose of this article is to conduct a narrative review and analyze the vulnerabilities of refugee children in Turkey from the lens of the Sustainable Development Goals (SDG), more specifically SDG Goal 3: Good Health and Wellbeing, with a specific focus on Syrian refugee children. Moreover, this article explores the actions taken to prevent and mitigate issues that arise from these vulnerabilities. Method: This narrative review article collected data from various primary and secondary sources on the Turkish refugee framework including national and international legislation, governmental and non-governmental data and reports, and scientific papers. Results: Syrian refugee children in Turkey are facing a variety of risks in terms of their health and wellbeing including communicable and non-communicable diseases, post-traumatic stress disorder, depression, family violence, child labor, and child marriage. The measures taken for prevention and response by governmental and non-governmental entities are multilateral and aim to address issues from multiple perspectives including medical, psychosocial, child protection, and legal. Conclusions: the interventions and restructuring of the health system in Turkey contribute to the SDG number 3 for refugee children. The existence of a legal system which enables refugee access to health, protection, and other social services is key to achieve this goal. However, the existing system could be improved especially through solidifying the legal basis and centralizing the implementation for child and refugee protection. The engagement of all stakeholders to imp, NA

As a distributed hash table (DHT) routing overlay, Skip Graph is used in a variety of peer-to-peer (P2P) systems including cloud storage. The overlay connectivity of P2P systems is negatively affected by the arrivals and departures of nodes to and from the system that is known as churn. Preserving connectivity of the overlay network (i.e., the reachability of every pair of nodes) under churn without compromising the overlay latency is a performance challenge in every P2P system including the Skip Graph-based ones. The existing decentralized churn stabilization solutions that are applicable to Skip Graphs mainly optimize the connectivity of the system under churn and do not consider routing latency of overlay as an optimization goal. Additionally, those existing solutions change the message complexity of Skip Graphs, distort its topology, or apply constant message overhead to the system. In this paper, we propose Interlaced, a fully decentralized churn stabilization mechanism for Skip Graphs that provides drastically stronger overlay connectivity and faster search queries without changing the asymptotic complexity of the Skip Graph in terms of storage, computation, and communication. We also propose the Sliding Window De Bruijn Graph (SWDBG ) as a tool to predict the availability of nodes with high accuracy. Our simulation results show that in comparison to the best existing DHT-based solutions, Interlaced improves the overlay connectivity of the Skip Graph under churn with the gain of about 1.73 times. Likewise, compared to the existing availability prediction approaches for P2P systems, SWDBG is about 1.26 times more accurate. A Skip Graph that benefits from Interlaced and SWDBG is about 2.47 times faster on average in routing the queries under churn compared to the best existing solutions. We also present an adaptive extension of Interlaced to be applied to other DHTs, for example, Kademlia., NA

This paper describes the elimination of healthcare-associated Acinetobacter baumannii infections in a highly endemic region. A prospective, observational study was performed between October 2012 and October 2017. Acinetobacter baumannii were isolated from 59 patients, and >95% similarity was demonstrated among isolates of seven patients (DiversiLab™, BioMérieux). Carbapenemase activity was detected in 15 of 17 (88%) isolates, and all were OXA-23 type. The control of Acinetobacter baumannii outbreaks can be achieved by close follow-up supported by molecular techniques, strict application of infection control measures, and isolation of transferred patients., NA

Molecular Communications (MC) is a bio-inspired communication technique that uses molecules to transfer information among bio-nano devices. In this paper, we focus on the detection problem for biological MC receivers employing ligand receptors to infer the transmitted messages encoded into the concentration of molecules, i.e., ligands. In practice, receptors are not ideally selective against target ligands, and in physiological environments, they can interact with multiple types of ligands at different reaction rates depending on their binding affinity. This molecular cross-talk can cause a substantial interference on MC. Here we consider a particular scenario, where there is non-negligible concentration of interferer molecules in the channel, which have similar receptor-binding characteristics with the information molecules, and the receiver employs single type of receptors. We investigate the performance of four different detection methods, which make use of different statistics of the ligand-receptor binding reactions: instantaneous number of bound receptors, unbound time durations of receptors, bound time durations of receptors, and combination of unbound and bound time durations of receptors within a sampling time interval. The performances of the introduced detection methods are evaluated in terms of bit error probability for varying strength of molecular interference, similarity between information and interferer molecules, number of receptors, and received concentration difference between bit-0 and bit-1 transmissions. We propose synthetic receptor designs that can convert the required receptor statistics to the concentration of intracellular molecules, and chemical reaction networks that can chemically perform the computations required for detection., European Union (EU); Horizon 2020; European Research Council (ERC); Project MINERVA; ERC-2013-CoG; AXA Research Fund

As a distributed hash table (DHT) routing overlay, Skip Graph is used in a variety of peer-to-peer (P2P) systems including cloud storage. The overlay connectivity of P2P systems is negatively affected by the arrivals and departures of nodes to and from the system that is known as churn. Preserving connectivity of the overlay network (i.e., the reachability of every pair of nodes) under churn without compromising the overlay latency is a performance challenge in every P2P system including the Skip Graph-based ones. The existing decentralized churn stabilization solutions that are applicable to Skip Graphs mainly optimize the connectivity of the system under churn and do not consider routing latency of overlay as an optimization goal. Additionally, those existing solutions change the message complexity of Skip Graphs, distort its topology, or apply constant message overhead to the system. In this paper, we propose Interlaced, a fully decentralized churn stabilization mechanism for Skip Graphs that provides drastically stronger overlay connectivity and faster search queries without changing the asymptotic complexity of the Skip Graph in terms of storage, computation, and communication. We also propose the Sliding Window De Bruijn Graph (SWDBG) as a tool to predict the availability of nodes with high accuracy. Our simulation results show that in comparison to the best existing DHT-based solutions, Interlaced improves the overlay connectivity of the Skip Graph under churn with the gain of about 1.73 times. Likewise, compared to the existing availability prediction approaches for P2P systems, SWDBG is about 1.26 times more accurate. A Skip Graph that benefits from Interlaced and SWDBG is about 2.47 times faster on average in routing the queries under churn compared to the best existing solutions. We also present an adaptive extension of Interlaced to be applied to other DHTs, for example, Kademlia., NA

In this paper we investigate a novel logistical problem. The goal is to determine daily tours for a traveling salesperson who collects rewards from activities in cities during a fixed campaign period. We refer to this problem as the Roaming Salesman Problem (RSP) motivated by real-world applications including election logistics, touristic trip planning and marketing campaigns. RSP can be characterized as a combination of the traditional Periodic TSP and the Prize-Collecting TSP with static arc costs and time-dependent node rewards. Commercial solvers are capable of solving small-size instances of the RSP to near optimality in a reasonable time. To tackle large-size instances we propose a two-phase matheuristic where the first phase deals with city selection while the second phase focuses on route generation. The latter capitalizes on an integer program to construct an optimal route among selected cities on a given day. The proposed matheuristic decomposes the RSP into as many subproblems as the number of campaign days. Computational results show that our approach provides near-optimal solutions in significantly shorter times compared to commercial solvers., NA

The aim of the paper is to define an infinitesimal analog of the Bloch regulator, which attaches to a pair of meromorphic functions on a Riemann surface, a line bundle with connection on the punctured surface. In the infinitesimal context, we consider a pair (X,X_) of schemes over a field of characteristic 0, such that the regular scheme X_ is defined in X by a square-zero sheaf of ideals which is locally free on X_. We propose a definition of the weight two motivic cohomology of X based on the Bloch group, which is defined in terms of the functional equation of the dilogarithm. The analog of the Bloch regulator is a map from a subspace of the infinitesimal part of HM 2(X,Q(2)) to the first cohomology group of the Zariski sheaf associated to an André-Quillen homology group. Using Goodwillie's theorem, we deduce that this map is an isomorphism, which is an infinitesimal analog of the injectivity conjecture for the Bloch regulator., NA

Edge computing moves the computation closer to the data and the data closer to the user to overcome the high latency communication of cloud computing. Storage at the edge allows data access with high speeds that enable latency-sensitive applications in areas such as autonomous driving and smart grid. However, several distributed services are typically designed for the cloud and building an efficient edge-enabled storage system is challenging because of the distributed and heterogeneous nature of the edge and its limited resources. In this paper, we propose EdgeKV, a decentralized storage system designed for the network edge. EdgeKV offers fast and reliable storage, utilizing data replication with strong consistency guarantees. With a location-transparent and interface-based design, EdgeKV can scale with a heterogeneous system of edge nodes. We implement a prototype of the EdgeKV modules in Golang and evaluate it in both the edge and cloud settings on the Grid’5000 testbed. We utilize the Yahoo! Cloud Serving Benchmark (YCSB) to analyze the system's performance under realistic workloads. Our evaluation results show that EdgeKV outperforms the cloud storage setting with both local and global data access with an average write response time and throughput improvements of 26% and 19% respectively under the same settings. Our evaluations also show that EdgeKV can scale with the number of clients, without sacrificing performance. Finally, we discuss the energy efficiency improvement when utilizing edge resources with EdgeKV instead of a centralized cloud., College of Engineering, Al Ain University

In this paper, we examine the cyclical dynamics of a Real Business Cycle model with ambiguity averse consumers and investment irreversibility using the smooth ambiguity model of Klibanoff et al. (2005, 2009). Ambiguity of belief about the productivity process arises as agents do not know the process driving variation in aggregate TFP, and they must make inferences regarding the true process at the same time as they infer the behavior of the unobserved temporary component using a Kalman filtering algorithm. Our findings may be summarized as follows. First, the standard business cycle facts hold in our framework, which are not altered significantly by changes in the degree of ambiguity aversion. Second, we demonstrate a role for information and learning effects, and show that lower initial ambiguity or greater confidence coupled with learning dynamics lowers the volatility and increases the persistence in all of the key macroeconomic variables. Third, comparing the performance of our model to the New Keynesian business cycle model of Ilut and Schneider (2014) with maxmin expected utility, we find that the version of their model without nominal and real frictions turns out to have limited success at matching the moments for the quantity variables. In the maxmin expected utility framework, the worst case scenario instills too much caution on the part of agents who, in the absence of a key set of nominal and real frictions, end up excessively reducing their responses to TFP shocks., British Academy; Newton Mobility Grant

The extraordinary steps taken by governments during the 2007-2009 financial crisis to prevent the failure of large financial institutions and support credit availability have invited heated debate. This paper comprehensively reviews empirical assessments of the benefits of those programs such as their effectiveness in reducing bank failures or supporting new lending introduces a combined dataset of five key programs that provided term debt or equity to banks in the U.S., and assesses the effects of such support on lending by U.S. banks. The results, using an instrumental variable approach, suggest that bank loans did not increase at institutions receiving government support., NA

Information Centric Networks (ICNs) have emerged in recent years as a new networking paradigm for the next-generation Internet. The primary goal of these networks is to provide effective mechanisms for content distribution and retrieval based on in-network content caching. Several network architectures were proposed in recent years to realize this communication model. This include Named Data Networks (NDN) and Path-Identifier (PID) based ICN. This paper proposes LogDoS as a novel mechanism to address the problem of data flooding attacks in PID-based ICNs. The proposed LogDoS mechanism is a unique hybrid approach that combines the best of NDN networks and PID-based ICNs, and it is the first to employ Bloom-filter based logging approach in a novel way to filter attack traffic efficiently. In this context, we develop and model three versions of LogDoS with varying levels of storage overhead at LogDoS-enabled routers. Extensive simulation experiments show that LogDoS is very effective against DDoS attacks as it can filter more than 99.98% of attack traffic in different attack scenarios while incurring acceptable storage overhead., Deanship of Research at Jordan University of Science and Technology

In both the Vickrey and eBay auctions, bidding the reservation price is the optimal strategy within the conventional utility framework. However, in practice, buyers tend to bid less than their reservation prices, and bid multiple times, thus increase their bids, in the course of an auction. In this paper, we show that both underbidding and multiple bidding behaviors can be consistent with utility maximization, if buyer's utility incorporates a transaction utility (reference price dependent) component. Transaction utility is based on the difference between the buyer's reference price and actual price paid; it captures the perceived value of the deal. More specifically, we show that the optimal bid is lower than the reservation price, but higher than the reference price. Furthermore, buyer may re-bid (above the prior optimal level) if the reference price is revised upon observing a higher current price., NA

For some years, the role of urodynamics (UDS) in female stress urinary incontinence (SUI) has been a topic of intense debate. The findings of the VaLUE and VUSIS-11 randomised clinical trials (RCTs) published in 2012 appeared to suggest that UDS is not useful in women with uncomplicated SUI, with the result that several authoritative guidelines were amended and the routine use of UDS in this setting fell sharply. However, many experts have raised concerns about the design of these two RCTs and their subsequent interpretation - including the inappropriate generalisation of the findings beyond uncomplicated cases, which represent only a small minority of the overall patient population. In this paper, we consider a range of issues and confounding factors which raise doubts about how influential these RCTs should have been and reflect on the potential value of UDS both for objective diagnosis and patient counselling in female SUI., NA

Recently, huge attention is attracted to the concept of integrating communication and radar missions within the same platform. Joint Radar-Communications (JRC) system gives an important opportunity to reduce spectrum usage and product cost while doing concurrent operation, as target sensing via radar processing and establishing communication links. A JRC-capable coherent MIMO radar system have been proposed recently in the literature. Several methods are introduced to reach dual goal as a notable null level towards the direction of interest of the radar and MIMO radar waveform orthogonality. Due to the limitations originated form the JRC operation, communication channel may encounter unwanted amplitude variations. This unwanted modulation normally affects the communication performance by its nature, due to the fades on radiated signal amplitude towards the direction of communication. However, the effect of this unintentional modulation on communication channel is yet to be investigated. In this paper, the communication channel for JRC capable phase-coded coherent MIMO radars is analyzed and investigated under additive white Gaussian noise and Rayleigh/Rician fading conditions. Communication capacity is evaluated for each channel condition. The results reveal that, using the single-side limited null direction fixed waveform generation method displays the best capacity performance under all channel conditions., NA

This paper presents measurements and statistical characterization to compare three potential bands of the low-THz channel, namely, the 300 to 319 GHz, 340 to 359 GHz and 380 to 399 GHz bands. From the large set of measurements performed in line-of-sight (LoS) and non-LoS (NLoS) environments, parameters for path loss model with shadowing are evaluated. Our results show that the path loss exponents for the band around 310 GHz, 350 GHz, and 390 GHz is 2.07, 1.90 and 1.96, respectively. The impacts of different materials acting as surfaces in LoS channels and reflectors in NLoS environments are also examined. Additionally, the statistical analysis due to temporal, spatial and multipath propagation is performed to determine the best fit distributions. Finally, we look at some networking scenarios in THz Band communication to derive the expressions for the number of connections a user can make based on antenna characteristics, data rate requirements and antenna mobility as well as network density. Our results suggest fundamental parameters that can be used in future THz Band analysis with applications in both macro and micro scale Internet of Things (IoT)., Scientific and Technological Research Council of Turkey (TÜBİTAK)

In this paper, a model of community formation and organizational complexity is presented, focusing on the fundamental role of social interactions and information transmission for the development of complex social organisation. The model combines several approaches in complex systems thinking which has garnered increasing attention in archaeology. It is then outlined how this conceptual model can be applied in archaeology. In the absence of direct observations of constituent social interactions, archaeologists study the past through material remnants found in the archaeological record. People used their material surroundings to shape, structure and guide social interactions and practices in various ways. The presented framework shows how dynamics of social organisation and community formation can be inferred from these material remains. The model is applied on a case study of two communities, Sagalassos and Düzen Tepe, located in southwestern Anatolia during late Achaemenid to middle Hellenistic times (fifth to second centuries BCE). It is suggested that constituent interactions and practices can be linked to the markedly different forms of organizational structures and material surroundings attested in both communities. The case study illustrates how the presented model can help understand trajectories of socio-political structures and organizational complexity on a community level., Research Foundation Flanders; Belgian Programme on Interuniversity Poles of Attraction, the Research Fund of the University of Leuven; Academic Foundation Leuven

Aggregate production planning (APP) that is an important concept of supply chain management (SCM), is one of the tools to determine production rates, inventory levels, and workforce requirements for fulfilling customer demands in a multi-period setting. Traditional APP models employ a single objective function to optimize monetary issues only. In this paper, we present a multi-objective APP model to analyze economic, social, environmental, and cultural pillars inclusively; moreover, each pillar includes several sub-pillars in the model. The resulting model includes an accurate representation of the problem with binary and continuous variables under sustainability considerations. We illustrate the effectiveness of the model in an appliance manufacturer and solve the problem using an exact solution method for multi-objective mixed-integer linear programs (MOMILP). We find a large number of the non-dominated (ND) points in the objective function space and analyze their trade-offs systematically. We show how this framework supports multiple criteria decision making process in the APP problems in the presence of sustainability considerations. Our approach provides a comprehensive analysis of the ND points of sustainable APP (SAPP) problems, and hence, the trade-offs of objective functions are insightful to the decision makers., IBM SUR award

The demand for wireless access continues to grow with the new applications which create a broad range of technical challenges. Although orthogonal frequency division multiplexing (OFDM) with multiple numerologies concept will likely address the current technical challenges of fifth generation (5G) wireless networks, the sufficiency of OFDM-based physical layer (PHY) is quite disputable due to massive growth trend on the number of wireless users and applications for future wireless networks. Therefore, enhanced radio access technologies (RATs) are needed to fulfill the technical requirements of beyond 5G networks. Generalized frequency division multiplexing (GFDM) has attracted tremendous attention over the past few years because of its advantages in terms of out-of-band (OOB) emission, spectral efficiency and latency. Index modulation (IM) techniques convey digital information by utilizing transmission entities in an innovative way and offer attractive advantages such as energy and spectral efficiency without increasing the computational complexity. On the other hand, multiple-input multiple-output (MIMO) transmission is an unquestionable technology to enable increased spectral efficiency. In this paper, a novel MIMO-GFDM scheme, which combines spatial multiplexing (SMX) MIMO transmission, GFDM and IM, is proposed in order to provide an efficient transmission scheme for beyond 5G wireless networks. A minimum mean squared error (MMSE)-QR decomposition-based near-optimum detector is proposed for the receiver side and bit error rate, OOB emission, spectral efficiency and computational complexity of the proposed scheme are compared with classical SMX-OFDM and SMX-GFDM schemes via computer simulations. It has been demonstrated that the proposed SMX-GFDM-IM scheme can be considered as a viable PHY scheme for beyond 5G wireless networks., NA

The increasing interest on spectrum resources causes various efforts on developing smart and compact solutions as joint radar-communication (JRC) systems. A JRC system can offer cost-effective solution with concurrent operation, as target sensing via radar processing and establishing communication links. JRC capability has been proposed over the years for different types of MIMO radars. However, a JRC capable monostatic coherent MIMO radar system is yet to be developed. These radars offer several advantages as fully coherent signal processing and coherent transmit beamforming which provides beampatterns to minimize probability of intercept. In this paper, two new waveform generation techniques suitable for JRC operation without disturbing transmit beamforming requirements and waveform orthogonality condition in space and time domain are proposed for monostatic coherent MIMO radars. Then, new communication methods are introduced for phase coded monostatic coherent MIMO radars. First method uses chirp-wise information encoding inside the radar pulse as intra-pulse communications. Second rotates the phase of a specific waveform on radiated symbols to a specific direction and the last method applies a small amount of progressive phase shift to the radar waveforms emitted from the antennas to create relative phase modulation between selected radar waveforms. Then, the performance of the proposed communication techniques are investigated in terms of bit error rate (BER) and generated waveforms are examined according to the orthogonality and transmit beamforming requirements., NA

Laminated composite plates are extensively used in various industries due to their high stiffness-to-weight ratio and directional properties that allow optimization of the stiffness characteristics for specific applications. In multi-objective optimization problems, optimal designs for individual performance metrics may be conflicting, necessitating knowledge on the design requirements for different metrics and potential trade-offs. In this paper, a multi-objective design methodology for laminated composite plates with dynamic and load-carrying requirements is presented. Lamination parameters are used to characterize laminate stiffness matrices in a compact form resulting in a convex design space. Single and multi-objective optimization studies are carried out to determine the optimal stiffness properties. For improving the dynamic performance, maximization of the fundamental frequency metric is aimed. For enhancing the load-carrying capability, buckling load and equivalent stiffness metrics are maximized. Conforming and conflicting behavior of multiple objective functions for different plate geometries, boundary conditions and load cases are presented by determining Pareto-optimal solutions. The results provide a valuable insight for multi-objective optimization of laminated composite plates and show that presented methodology can be used in the design of such structures for improving the dynamic and load-carrying performance., European Union (European Union); H2020; European Union Seventh Framework Programme; FP7-PEOPLE-2012-ITN; Marie Curie Initial Training Network; Aerospace Multidisciplinarity Enabling DEsign Optimization (AMEDEO)

This paper investigates the acoustic superradiance of the density and phase fluctuations from the single vortex state of a Bose-Einstein condensate, by employing full time-domain and asymptotic frequency domain numerical calculations. The draining bathtub model of an incompressible barotropic fluid is adopted to describe the vortex. The propagation of the axisymmetric density and phase fluctuations in the condensate are governed by the massless scalar Klein-Gordon wave equation, which establishes the rotating black-hole analogy. Hence, the amplified scattering of these fluctuations from the vortex comprise the superradiance effect. A particular coordinate transformation is applied to reveal the event horizon and the ergosphere termwise in the metric and the respective asymptotic spectral solutions. A comparative analysis of the time domain and asymptotic frequency domain results are given for a range of rotational speed of the vortex and the frequency of the impinging fluctuations. The agreement at low rotational speeds of the vortex is shown to be very good, which starts to deteriorate at higher rotational speeds due to increasing constraint violations of the time-domain calculations. We further demonstrate an asymptotic upper bound for the superradiance as a function of vortex rotational speed, provided that the vortex remains stable., Scientific and Technological Research Council of Turkey (TÜBİTAK) BIDEB 2211 National Scholarship Program

The information from outside world is encoded into spikes by the sensory neurons. These spikes are further propagated to different brain regions through various neural pathways. In the cortical region, each neuron receives inputs from multiple neurons that change its membrane potential. If the accumulated change in the membrane potential is more than a threshold value, a spike is generated. According to various studies in neuroscience, this spiking threshold adapts with time depending on the previous spike. This causes short-term changes in the neural responses giving rise to short-term plasticity. Therefore, in this paper, we analyze a multiple-input single-output (MISO) neuro-spike communication channel and study the effects of dynamic spiking threshold on mutual information and maximum achievable sum rate of the channel. Since spike generation consumes a generous portion of the metabolic energy provided to the brain, we further put metabolic constraint in calculating the mutual information and find a trade-off between maximum achievable sum rate and metabolic energy consumed. Moreover, we analyze three types of neurons present in the cortical region, i.e., Regular spiking, Intrinsic bursting and Fast spiking neurons. We aim to characterize these neurons in terms of encoding/transmission rates and energy expenditure. It will provide a guideline for the practical implementation of bio-inspired nanonetworks as well as for the development of ICT-based diagnosis and treatment techniques for neural diseases., European Union (European Union); European Research Council (ERC); MINERVA; MINRGRACE

In this paper, we introduce RF energy harvesting paradigm into WNCS framework to study the optimal power control, energy harvesting and scheduling problem with the objective of providing maximum level of adaptivity under strict timing and reliability requirements employing the constant rate transmission model. We formulate the problem as a Mixed Integer Linear Programming Problem (MILP). We show the power allocation can be separated from the scheduling and harvesting at optimality. Then, we introduce a heuristic algorithm for the scheduling problem, periodic list scheduling (PLS), inspired from list scheduling of jobs with sequence dependent setup times on identical machines. We then demonstrate via extensive simulations the superiority of the proposed algorithm in terms of closeness to the optimal, adaptivity and runtime., Nazarbayev University; Research Centre of AUEB; National Analytical Center 'Analytica'

The cross-talk between different signal transduction pathways plays a key role in the regulation of cellular functions. This paper models the major feedback loops involved in the cross-talk between AKT and ERK signaling pathways. The developed models can be used to improve our understanding of the complex interactions between two important pathways at the systems level., Scientific and Technological Research Council of Turkey (TÜBİTAK)

This paper explores the implications of spatial production of academic knowledge on the Middle East, through the critiques of Orientalist discourses on the "Muslim woman." It begins with an examination of the success of postcolonial studies and scholarship on democratization in challenging racist perceptions and polities in the West. Then it reflects on the ways in which this knowledge production travels and is reconfigured in places where power inequalities are different. This requires a consideration of the regional consequences of either an over-emphasis on differences in agencies of "Muslim women" or a relative silence on issues of gender inequality. The paper's suggestion is to shift the focus from representation and discourse to the structural circumstances in which ordinary men and women's agencies play out; various political mechanisms which participate in the production of acceptable cultural practices; and patterns of resistance, which may defy arguments about culturally specific definitions of agency. This is a quest for making the "exotic" familiar, without exoticizing the familiar., NA

High throughput capability of the terahertz band (0.3-10 THz) wireless communications is expected to be utilized by the fifth generation of mobile telecommunication systems and enable a plethora of new applications. Supporting devices will transfer large amounts of data in both directions, causing high energy consumption by the electronic circuitries of the equipment in use. Therefore, physical layer for these systems must be designed carefully in order to reduce energy consumption per bit. In this paper, the best performing modulation scheme and hardware parameters that minimize the energy consumption without affecting the system throughput are determined. THz band device technologies are outlined and a complete survey of the state-of-the-art low-THz band circuit blocks which are suitable for mass market production is given. It is shown that for short-range communications, M-ary quadrature amplitude modulation is the most energy-efficient technique that can lead up to 90% reduction in consumed energy. Moreover, optimal transceiver parameters which can be used to further minimize the energy consumption of the THz band system are examined., Scientific and Technological Research Council of Turkey (TÜBİTAK)

In this paper, we analyze the role of hidden bias in representational efficiency of the Gaussian-Bipolar Restricted Boltzmann Machines (GBPRBMs), which are similar to the widely used Gaussian-Bernoulli RBMs. Our experiments show that hidden bias plays an important role in shaping of the probability density function of the visible units. We define hidden entropy and propose it as a measure of representational efficiency of the model. By using this measure, we investigate the effect of hidden bias on the hidden entropy and provide a full analysis of the hidden entropy as function of the hidden bias for small models with up to three hidden units. We also provide an insight into understanding of the representational efficiency of the larger scale models. Furthermore, we introduce Normalized Empirical Hidden Entropy (NEHE) as an alternative to hidden entropy that can be computed for large models. Experiments on the MNIST, CIFAR-10 and Faces data sets show that NEHE can serve as measure of representational efficiency and gives an insight on minimum number of hidden units required to represent the data., NA

Even though kidney exchange became an important source of kidney transplants over the last decade with the introduction of market design techniques to organ transplantation, the shortage of kidneys for transplantation is greater than ever. Due to biological disadvantages, patient populations of blood types B/O are disproportionately hurt by this increasing shortage. The disadvantaged blood types are overrepresented among minorities in the US. In order to mitigate the disproportionate harm to these biologically disadvantaged groups, the UNOS reformed in 2014 the US deceased-donor kidney-allocation system, utilizing a technological advance in blood typing. The improved technology allows a certain fraction of blood type A kidneys, referred to as subtype A2 kidneys, to be transplanted to medically qualified patients of blood types B/O. The recent reform prioritizes subtype A2 deceased-donor kidneys for blood type B patients only. When restricted to the deceased-donor allocation system, this is merely a distributional reform with no adverse impact on the overall welfare of the patient population. In this paper we show that the current implementation of the reform has an unintended consequence, and it de facto extends the preferential allocation to kidney exchange as well. Ironically this "spillover" not only reduces the number of living-donor transplants for the overall patient population, but also for the biologically disadvantaged groups who are the intended beneficiaries of the reform. We show that minor variations of the current policy do not suffer from this unintended consequence, and we make two easy-to-implement, welfare-increasing policy recommendations., Goldman Sachs Faculty Research Fund; NSF; Scientific and Technological Research Council of Turkey (TÜBİTAK)

In this paper we use counting arguments to prove that the expected percentage coverage of a d dimensional parameter space of size n when performing k trials with either Latin Hypercube sampling or Orthogonal Array-based Latin Hypercube sampling is the same. We then extend these results to an experimental design setting by projecting onto a t < d dimensional subspace. These results are confirmed by simulations. The theory presented has both theoretical and practical significance in modelling and simulation science when sampling over high dimensional spaces., University of Queensland Centre for Coal Seam Gas; APLNG; Arrow Energy; Santos; QGC (Shell); Scientific and Technological Research Council of Turkey (TÜBİTAK)

Spatial skills are essential for everyday tasks, and technology blends seamlessly into children's everyday environment. Since spatiality as a term is ubiquitous in experience this paper bridges literature in two fields: theories on early spatial learning in cognitive development and potential benefits of tangible user interfaces (TUIs) for supporting very young children's spatial skills. Studies suggest that the period between 2 and 4 years of age is critical for training spatial skills (e.g., mental rotation), which relate to further success in STEAM (science, technology, engineering, arts, and math) disciplines. We first present a review of the empirical findings on spatial skills, early interventions, and tools (i.e., narrative and gesture input) recommended for training preschool children's spatial skills. By situating the work within the use and benefits of manipulatives (e.g., building blocks, puzzles, shapes) combined with digital affordances in interaction design, we address the relevance of TUIs as complementary tools for spatial learning. We concentrate on the supporting properties of TUIs that enable playful learning, make storytelling more concrete, and provide embodiment effects through physicality. Through various products found in the market and literature that address the physical–digital convergence, we invite designers and researchers to consider design practices and applicable technology that build on present efforts and paradigms in this area. To contribute to this area, we conclude with a discussion of the gaps in design methods to develop technologies for children younger than 4 years old, and propose directions for future work to leverage new tools that serve very young children's spatial learning and possible inquiries for dual payoff., NA

Wireless mesh networks (WMNs) provide cost-effective alternatives for extending wireless communication over larger geographical areas. In this paper, given a WMN with its nodes and possible wireless links, we consider the problem of gateway node selection for connecting the network to the Internet along with operational problems such as routing, wireless transmission capacity allocation, and transmission power control for efficient use of wired and wireless resources. Under the assumption that each node of the WMN has a fixed traffic rate, our goal is to allocate capacities to the nodes in proportion to their traffic rates so as to maximize the minimum capacity-to-demand ratio, referred to as the service level. We adopt a time division multiple access (TDMA) scheme, in which a time frame on the same frequency channel is divided into several time slots and each node can transmit in one or more time slots. We propose two mixed integer linear programming formulations. The first formulation, which is based on individual transmissions in each time slot, is a straightforward extension of a previous formulation developed by the authors for a related problem under a different set of assumptions. The alternative formulation, on the other hand, is based on sets of noninterfering wireless transmissions. In contrast with the first formulation, the size of the alternative formulation is independent of the number of time slots in a frame. We identify simple necessary and sufficient conditions for simultaneous transmissions on different links of the network in the same time slot without any significant interference. Our characterization, as a byproduct, prescribes a power level for each of the transmitting nodes. Motivated by this characterization, we propose a simple scheme to enumerate all sets of noninterfering transmissions, which is used as an input for the alternative formulation. We also introduce a set of valid inequalities for both formulations. For large instances, we pr, Scientific and Technological Research Council of Turkey (TÜBİTAK); Turkish Academy of Sciences Young Scientists Award Program (Turkish Academy of Sciences (TÜBA) - GEBIP)

The main constraints in high performance machining of the titanium alloys are mostly due to the friction induced thermal issues. In thermal analysis, the friction coefficient is the critical parameter for estimating the heat generation at the tool-chip interface. This paper provides a direct approach for determining the friction coefficient from slot milling of Ti6Al4V for uncoated solid carbide end-mills and AlTiN coated tools with magnetic, friction and sandblast finishing techniques. The effects of AlTiN coating and finishing techniques on friction coefficients are investigated., Scientific and Technological Research Council of Turkey (TÜBİTAK)

Communication requirements for cognitive radio sensor networks (CRSN) necessitate addressing the problems posed by dynamic spectrum access (DSA) in an inherently resource-constrained sensor networks regime. In this paper, arising challenges for reliability and congestion control due to incorporation of cognitive radio capability into sensor networks are investigated along with the open research issues. Impact of DSA, i.e., activity of licensed users, intermittent spectrum sensing and spectrum handoff functionalities based on spectrum availability, on the performance of the existing transport protocols are inspected. The objective of this paper is to point out the urgent need for a novel reliability and congestion control mechanism for CRSN. To this end. CRSN challenges for transport layer are revealed and simulation experiments are performed to demonstrate the performance of the existing transport protocols in CRSN., Scientific and Technological Research Council of Turkey (TÜBİTAK); Turkish National Academy of Sciences (Turkish Academy of Sciences (TÜBA)-GEBIP)

Performance evaluation of transport layer protocols in cognitive radio sensor networks (CRSNs) is useful to provide quality-of-service for real-time reliable applications. This paper develops an analytical framework to model the steady-state sending rate of collecting cognitive radio (CR) sensors in rate-based generic additive-increase multiplicative-decrease (AIMD) and additive-increase additive-decrease (AIAD) congestion control schemes. Evolution process of sending rate is modeled by a discrete time Markov chain (DTMC) in the terms of queue length. We model the queue length distribution of a CR node by a semi-Markov chain (SMC) with assuming general probability density functions (PDFs) of input rate and attainable sending rate of the node. These PDFs are derived based on the parameters of MAC and physical layers and CRSN configuration. The proposed models are verified through various simulations., Iran Telecommunication Research Center (ITRC), Iran Telecommunication Research Center (ITRC)

Reliability is one of the most important requirements in Smart Grid communications. Reliable detection of an emergency event enables timely response. Within the automated nature of Smart Grid, such detection and response are carried out by sensor and actuator nodes. Therefore, it is important to study the capabilities of wireless sensor actor networks. In this paper, we first present an analysis of reliability in sensor actor networks, and lay out the factors that affect reliability. We then propose a scheme, where actor nodes cooperate to reach a global estimate under interruptions due to licensed user interference, i.e., consensus. We show that consensus improves reliability compared to local estimation of event features. We further show that convergence rate depends on connectivity of actors. Our analyses are generic and can be applied to inhomogeneous licensed user activity and interference on channels. A simulation study is presented to support our analyses and demonstrate the performance of proposed scheme in achieving consensus and mitigating disagreement among actor nodes., NA

Performance guarantees for congestion control schemes in cognitive radio sensor networks (CRSNs) can be helpful in order to satisfy the quality of service (QoS) in different applications. Because of the high dynamicity of available bandwidth and network resources in CRSNs, it is more effective to use the stochastic guarantees. In this paper, the stochastic backlog and delay bounds of generic rate-based additive increase and multiplicative decrease (AIMD) congestion control scheme are modeled based on stochastic network calculus (SNC). Particularly, the probabilistic bounds are modeled through moment generating function (MGF)-based SNC with regard to the sending rate distribution of CR source sensors. The proposed stochastic bounds are verified through NS2-based simulations., Iran Telecommunication Research Center (ITRC), Iran Telecommunication Research Center (ITRC)

5-axis sculptured surface milling is a difficult machining process to model due to the complex geometrical engagement between the workpiece and the cutter. Due to the complexity of the process, the engagement cannot be found analytically with conventional methods. Therefore, solid modeler based simulations are utilized to compute the engagement map. This paper presents a comprehensive and efficient strategy for engagement modeling of ball end milling using a solid modeler kernel, namely Parasolid. Accuracy of the model is validated by simulating the cutting forces based on the calculated engagements and compare it with experimentally measured cutting forces. (C) 2015 The Authors. Published by Elsevier B. V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)., NA

Mobile data traffic is constantly rising at huge growth rates. One evolving method to counter this expansion is operation frequency, and so bandwidth, increase, as formal standardization activities on 60 gigahertz industrial, scientific and medical radio band began in 2005. In line with this, this paper proposes the utilization of low terahertz (THz) band for the next-generation of mobile and wireless communications systems. Following the introduction and an overview of the low-THz band propagation properties, representative indoor simulations comparing the current fourth generation and proposed high frequency fifth generation networks are presented. The results show that, while it is possible to form and maintain stable communication links at low-THz band, techniques to reduce signal attenuation should be researched within all related subjects., Scientific and Technological Research Council of Turkey (TÜBİTAK)

Nanonetworks is an emerging field of study where nanomachines communicate to work beyond their individual limited processing capabilities and perform complicated tasks. The human body is an example of a very large nanoscale communication network, where individual constituents communicate by means of molecular nanonetworks. Amongst the various intra-body networks, the nervous system forms the largest and the most complex network. In this paper, we introduce a queueing theory based delay analysis model for neuro-spike communication between two neurons. Using standard queueing model blocks such as servers, queues and fork-join networks, impulse reception and processing through the nervous system is modeled as arrival and service processes in queues. Simulations show that the response time characteristics of the model are comparable to those of the biological neurons., European Research Council (ERC); Minerva; Scientific and Technological Research Council of Turkey (TÜBİTAK) (Scientific and Technological Research Council of Turkey (TÜBİTAK)); Turkish National Academy of Sciences Distinguished Young Scientist Award Program (Turkish Academy of Sciences (TÜBA)-GEBİP); IBM through IBM Faculty Award

One reason for heat losses in buildings is inadequate insulation. Vacuum Insulation Panels (vips) is emerging as a promising solution, being more energy efficient than conventional insulation materials, thinner and lighter. A VIP is made by placing a core insulation material inside a gas-barrier envelope and evacuating the air from inside the panel. The limitations to wide-scale VIP commercialization lie in lack of low-cost and high-volume processes to turn them into products suitable for use in buildings, and their short in-service lifetimes. These drawbacks were researched in a European funded project "nanoinsulate", and this paper gives an overview of results., European Union Commission Seventh Framework Programme Project “NanoInsulate”

Residual stress is a key factor that influences the reliability, precision, and life of final products. Earlier studies have alluded to the fact that the grinding process is usually the source of a tensile residual stress on the part surface, while there exists a temperature level commonly referred to as the onset tensile temperature beyond which the tensile profile of residual stresses starts to be generated. In this paper, a physics-based model is proposed to predict the onset temperature as a function of residual stress on an analytical and quantitative basis. The predictive model is based on the temperature distribution function using a moving heat source approach. Then, the thermal stresses are calculated analytically using Timoshenko thermal stress theory [1] followed by an elastic-plastic relaxation condition imposed on these stresses, thus leading to the resulting residual stresses. The model-predicted results have been experimentally validated using data of the grinding of AISI52100 hardened steel with subsequent X-ray and Neutron diffraction measurements. The model was shown to predict the residual stress profile under given process conditions and material properties, therefore providing an analytical tool for grinding process planning and optimization based on the understanding of onset tensile temperature for control of tensile residual stresses. (C) 2014 Elsevier B.V., NA

We show that a pair of orthogonal partial Latin squares of order n can be embedded in a pair of orthogonal Latin squares of order at most 16n(4) and all orders greater than or equal to 48n(4). This paper provides the first direct polynomial order embedding construction for pairs of orthogonal partial Latin squares., NA

In this paper we introduce a network coding-aided energy efficient Medium Access Control (MAC) protocol that coordinates the transmissions among a set of relay nodes which act as helpers in cooperative Automatic Repeat reQuest-based (ARQ-based) wireless networks. Applying network coding techniques, we achieve to increase the energy efficiency of the network without compromising the system performance in terms of Quality of Service. Our proposed solution is evaluated by both analytical and simulation results., Research Project CO2GREEN; Research Project Green-T; Research Project GREENET; Scientific and Technological Research Council of Turkey (TÜBİTAK); Türk Telekom

Users frequently reuse their passwords when authenticating to various online services. Combined with the use of weak passwords or honeypot/phishing attacks, this brings high risks to the security of the user’s account information. In this paper, we propose several protocols that can allow a user to use a single password to authenticate to multiple services securely. All our constructions provably protect the user from dictionary attacks on the password, and cross-site impersonation or honeypot attacks by the online service providers. Our solutions assume the user has access to either an untrusted online cloud storage service (as per Boyen [16]), or a mobile storage device that is trusted until stolen. In the cloud storage scenario, we consider schemes that optimize for either storage server or online service performance, as well as anonymity and unlinkability of the user’s actions. In the mobile storage scenario, we minimize the assumptions we make about the capabilities of the mobile device: we donotassume synchronization, tamper resistance, special or expensive hardware, or extensive cryptographic capabilities. Most importantly, the user’s password remains secure even after the mobile device is stolen. Our protocols provide another layer of security against malware and phishing. To the best of our knowledge, we are the first to propose such various and provably secure password-based authentication schemes. Lastly, we argue that our constructions are relatively easy to deploy, especially if a few single sign-on services (e.g., Microsoft, Google, and Facebook) adopt our proposal., NA