Proactive controller assignment schemes in SDN for fast recovery

​© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.A sizeable software defined network with a single controller responsible for all forwarding elements is potentially failure-prone and inadequate for dynamic network loads. To this end, having multiple controllers improves resilience and distributes network control overhead. However, when there is a disruption in the control plane, a rapid and performant controller-switch assignment is critical, which is a challenging technical question. In this work, we propose a proactive switch assignment approach in case of controller failures using a genetic algorithm based heuristic that considers controller load distribution, reassignment cost and probability of failure. Moreover, we compare the performance of our scheme with random and greedy algorithms. Experiment results show that our proposed PREFCP framework has better performance in terms of probability of failure and controller load distributio

The comparative effects of esmolol and amiodarone on isolated coronary artery bypass grafts

Background/aim: Esmolol and amiodarone are two most commonly used antiarrhythmic drugs in coronary artery bypass grafting (CABG) surgery. Nevertheless, blockade of beta-2 receptors by increasing doses raise concerns about possible vasospasms. We studied the vasoactive effects of amiodarone and esmolol on left internal mammary artery (LIMA), radial artery (RA), and saphenous vein (SV) grafts. Materials and methods: After determining the presence of functional smooth muscle and endothelial layers, the responses of submaximally preconstricted graft samples were recorded in a tissue bath system. A total of 96 graft samples from 40 patients were used: 16 LIMA, 16 RA, and 16 SV grafts for each drug. Esmolol and amiodarone were added to reservoirs separately, starting from a concentration of 10-8 M until a concentration of 10-4 M. Results: Although both drugs caused vasodilatation, amiodarone exhibited a more potent vasodilatory effect than esmolol (P < 0.0001 for LIMA, P = 0.0128 for RA, and P < 0.0001 for SV). The vasodilatation rates with esmolol were 48.99 +/- 1. 2.28% in LIMA, 49.77 +/- 3.03% in RA, and 41.90 +/- 4.05% in SV grafts and with amiodarone they were 71.65 +/- 5.18% in LIMA, 58.61 +/- 5.87% in RA, and 65.07 +/- 4.09% in SV grafts. Conclusion: This in vitro study revealed that even increasing doses of both drugs induce vasodilatation of CABG grafts, with amiodarone having a more potent vasodilatory effect than esmolol

Expansive networks : exploiting spectrum sharing for capacity boost and 6G vision

Adaptive capacity with cost-efficient resource provisioning is a crucial capability for future 6G networks. In this work, we conceptualize "expansive networks" which refers to a networking paradigm where networks should be able to extend their resource base by opportunistic but self-controlled expansive actions. To this end, we elaborate on a key aspect of an expansive network as a concrete example: Spectrum resource at the PHY layer. Evidently, future wireless networks need to provide efficient mechanisms to coexist in the licensed and unlicensed bands and operate in expansive mode. In this work, we first describe spectrum sharing issues and possibilities in 6G networks for expansive networks. We then present security implications of expansive networks, an important concern due to more open and coupled systems in expansive networks. We also discuss two key enablers, namely distributed ledger technology (DLT) and network intelligence via machine learning, which are promising to realize expansive networks for the spectrum sharing aspect

The Effect of Speciality Designated Core Exercises on Upper Exterimity Posture Structures of Male High School Students

The aim of this study is to research on the effect of core exercises on the upper extremity posture structure of young individuals. 30 male students between 16 to 18 years old studying in a high school in the province of Elazig and not doing regular sport volunteered for this study. The participants were randomly divided into two as the subject group and the control group; each group was formed with 15 people. Out of the groups formed, the subject group carried out specially designated core exercises for 8 weeks, and for 3 days each week. The control group didn't do any work; they continued their normal lives. Before and after the study, the height, weight, body mass index, bodily fat percentage, upper extremity posture(from the front, back, right and left)of the subject and control groups formed were measured and the Adams(stoop) test was applied. The data obtained were analyzed through SPSS 22.0 statistical program. For the in-group and intergroup comparisons, ındependent samples T test and paired samples T test were used. After the statistical analysis, during the initial and subsequent test comparisons of the control group, no difference was detected in measurements apart from the one for shoulders from the anterior side. Statistical differences were determined for a lot of values during the comparison of the initial and subsequent test results of the subject group and during the comparison of the differences between the initial and subsequent test results of the subject and control group. In conclusion, it was determined that core exercises made a positive impact on the upper extremity posture structures of male individuals between the ages of 16 and 18.

Caching and D2D sharing for content delivery in software-defined UAV networks

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.In cases of catastrophic events such as natural disasters or physical calamities, current network infrastructure can become inoperative. Furthermore, there are transient events leading to excessive demand surges where it is needed to deploy additional network capacity on-demand. In such cases, rapid network deployments become vital to establish communications and enable networked services. Unmanned Aerial Vehicle (UAV) networks are good candidates for this kind of operation. Software-defined networking and content-centric operation are promising technologies to enable agile control, network visibility and efficient content delivery via centralized optimization in these challenged systems. In this work, we consider an edge network which is composed of UAVs and serves in a content-centric mode with in-network caching and device-to-device (D2D) transmissions. We develop a cache placement and selection scheme for energy efficient operation. We also investigate how such a system performs under different operating conditions

Is using metaproterenol sulfate reliable in hypertension management during the coronary artery bypass graft surgery in terms of graft patency?

Introduction: Coronary artery bypass graft (CABG) surgery that is a basic revascularization method is used commonly and hypertension appears frequently during and after CABG operations. In the treatment of hypertension, metaproterenol sulfate (MS) is one of the main agents; however, the effects of this agent on grafts are not known at an adequate level. The aim of the present study was to determine whether MS could be used safely in CABG operations by examining its effects on coronary grafts. Material and Methods: This cross-sectional, prospective, experimental study was conducted at a university hospital. In this study, internal thoracic artery (ITA), radial artery (RA) and saphenous vein (SV) graft materials were studied in organ bath in patients who underwent CABG surgery between 2013 and 2016. In the organ bath, 10-6 phenylephrine was added to the grafts to ensure that the ITA, RA and SV grafts contracted submaximally. Then, by adding MS with the cumulative method, the resulting relaxation results were recorded and dose-response curves were created. The p < 0.05 was considered as significant. Results: A total of 30 patients were included in the study. The average age of the participants was 59.3 (45-81) years. Minimum 1 and maximum 6 grafts (2.96 in average) were taken from all patients. Relaxation response was formed in the ITA at a rate of 40.49% ± 13.52, in the RA at a rate of 28.41% ± 9.08 and in the SV at a rate of 23.87% ± 8.36 by adding MS with the cumulative method. In the statistical work that was done by comparing the relaxation values among the SV grafts, ITA and RA grafts, it was determined that the efficacy of MS in the SV grafts was significantly lower when compared with the ITA and RA grafts. Conclusions: In the present study, it was concluded that the risk of developing vasospasm was low in all three grafts when MS was used in intraoperative and postoperative periods. However, in the long-term, this made us consider that better graft patency rates might be obtained. Multicenter in-vivo studies with larger patient groups are needed to support our findings. © 2021 Via Medica

Symptomatic huge pericardial cyst: a case report

Mediastinal kistler nadir gözlenen, konjenital, neoplastik ve inflamatuar kaynaklı patolojilerdir. Basit perikardiyal kistler tüm yaş gruplarında görülmekle beraber sıklıkla yetişkin yaş grubunda gözlenmektedir. Perikardiyal kistler tüm mediastinal kistler arasında %7 gibi bir oranda gözlenmektedir. Hastaların kliniği sıklıkla asemptomatik seyretmektedir. Semptomlar nadir gözlenmekle beraber %20-30 olguda semptomatik olup ağrı, nefes darlığı, taşipne ve öksürük en sık gözlenen semptomlardır. Kistin kardiyak basısına bağlı olarak hipotansiyon, aritmi, atrial fibrilasyon ya da ani kardiyak ölüm semptomlarda gözlenebilmektedir. X-ray, bilgisayarlı tomografi, ekokardiografi gibi tetkikler ile saptanmaktadır. Yazımızda 35 yaşında, medikal tedaviye dirençli hipotansiyon, aritmi ve nefes darlığı olan, sağ atriuma bası yapan perikardiyal kist olgusunu sunduk.Mediastinal cysts are uncommon and results from congenital, neoblastic or inflamatuar abnormalities. Pericardial cyst may occur in patients of all ages, but commonly present in adults. The overall incidence of pericardial cyst is 7% in mediastinal cysts. The clinical presentation is commonly asymtomatic. Pain, tachpnea, dsypne and cough is the most common symptoms. Tachycardie, hypotansion, arytmi and sudden death are usually because of cardiac compression by the cystic mass.They are commonly found incidentally upon chest radiography, computed tomography or echocardiograph. We present, herein, the case of a 35-year-old female with a symptoms of dsypne, hypotansion and atrial arrhythmia resistant to medical therapies with finding of a pericardial cyst compression to the lateral wall of the right atrium