The P-ART framework for placement of virtual network services in a multi-cloud environment

Carriers network services are distributed, dynamic, and investment intensive. Deploying them as virtual network services (VNS) brings the promise of low-cost agile deployments, which reduce time to market new services. If these virtual services are hosted dynamically over multiple clouds, greater flexibility in optimizing performance and cost can be achieved. On the flip side, when orchestrated over multiple clouds, the stringent performance norms for carrier services become difficult to meet, necessitating novel and innovative placement strategies. In selecting the appropriate combination of clouds for placement, it is important to look ahead and visualize the environment that will exist at the time a virtual network service is actually activated. This serves multiple purposes clouds can be selected to optimize the cost, the chosen performance parameters can be kept within the defined limits, and the speed of placement can be increased. In this paper, we propose the P-ART (Predictive-Adaptive Real Time) framework that relies on predictive-deductive features to achieve these objectives. With so much riding on predictions, we include in our framework a novel concept-drift compensation technique to make the predictions closer to reality by taking care of long-term traffic variations. At the same time, near real-time update of the prediction models takes care of sudden short-term variations. These predictions are then used by a new randomized placement heuristic that carries out a fast cloud selection using a least-cost latency-constrained policy. An empirical analysis carried out using datasets from a queuing-theoretic model and also through implementation on CloudLab, proves the effectiveness of the P-ART framework. The placement system works fast, placing thousands of functions in a sub-minute time frame with a high acceptance ratio, making it suitable for dynamic placement. We expect the framework to be an important step in making the deployment of carrier-grade VNS on multi-cloud systems, using network function virtualization (NFV), a reality.This publication was made possible by NPRP grant # 8-634-1-131 from the Qatar National Research Fund (a member of Qatar Foundation), National Science Foundation, USA � CNS-1718929 and National Science Foundation, USA � CNS-1547380 .Scopu

Radiological outcome of hamstring graft after anterior cruciate ligament reconstruction with augmentation of bone marrow aspirate concentrate

Background: Anterior cruciate ligament (ACL) tears are common injuries in the athletic population. Surgical intervention is required for ACL tears as it restores the knee function and it prevents early osteoarthritis. In the recent research there is increasing use of bone marrow aspirate concentrate in orthopaedics. Bone marrow aspirate concentrate (BMAC) provides mesenchymal stem cells progenitor cells and growth factors which has potential benefits in hamstring graft healing after ACL reconstruction.Methods: This was a prospective randomized case control study carried out between May 2017 and June 2020. 30 patients between age group of 18 to 40 years with complete ACL tear were divided into two groups which consisted of the control group in which only ACL reconstruction was done and second group in which ACL reconstruction was done augmenting it with bone marrow aspirate concentrate. For the BMAC group, 3 ml of BMAC was obtained in the operation theatre itself and was injected into femoral tunnel and the tibia tunnel just before portal suturing. MRI was obtained post operatively at 6 months and at 1 year. Graft healing was seen as the time taken for the graft to reach ligamentization phase when the graft became hyper intense or was visualized similar to PCL or the remnant which was preserved during reconstruction in all cases.Results: Most of the patients in which augmentation (86%) was done healed at 6 month as compared to those who were not augmented (13%).Conclusions: BMAC showed faster and better healing of the graft in ACL reconstruction

Determination of the Optimal Reduction Ratio for Least Springback during Cold Drawing of Seamless Tubes

Cold drawing process is one of the most used metals forming processes in industries for forming seamless tubes. This process of plastic deformation of metals occurs below the recrystallization temperature and is generally performed at room temperature. When metal is cold worked, upon the release of forming force, the springback occurs. In this paper, the springback effect of the seamless tube that has undergone cold drawing is studied for three different reduction ratios viz.10-15 %,15-20 %, and 20-25 % having the aim to reduce it. Experiments are conducted under different reduction ratios with working conditions of die semi angles of 10 and 15 degrees, die land width of 5 mm and 10 mm as well as drawing speed of 4, 6, and 8 m/min for C-45 tube material. Optimum reduction ratio is finalized using Statistical Package for Social Science (SPSS) software of data analysis using statistical tests like Kruskal-Wallis, ANOVA, Post-hoc, etc. Metallurgical analysis through microstructural investigation, XRD and mechanical testing via cold draw load, and hardness testing for different reduction ratios are also studied for validation purposes. The results of this research show that 10-15 % reduction ratio yields the minimum springback. This can be used to help designing tools in the metal forming industry to minimize springback and improve the quality of the product

Enhanced Distributed File Replication Protocol for Efficient File Sharing in Wireless Mobile Ad-Hoc Networks.

File sharing applications in mobile unintended networks (MANETs) have attracted additional and additional attention in recent years. The potency of file querying suffers from the distinctive properties of such networks as well as node quality and restricted communication vary and resource. associate degree intuitive methodology to alleviate this drawback is to form file replicas within the network. However, despite the efforts on file replication, no analysis has targeted on the worldwide optimum duplicate creation with minimum average querying delay. Specifically, current file replication protocols in mobile unintended networks have 2 shortcomings. First, they lack a rule to portion restricted resources to completely different files so as to reduce the typical querying delay. Second, they merely contemplate storage as offered resources for replicas, however neglect the actual fact that the file holders’ frequency of meeting different nodes additionally plays a crucial role in deciding file availableness. Actually, a node that contains a higher meeting frequency with others provides higher availableness to its files. This becomes even additional evident in sparsely distributed MANETs, during which nodes meet disruptively. during this paper, we have a tendency to introduce a replacement conception of resource for file replication, that considers each node storage and meeting frequency. we have a tendency to on paper study the influence of resource allocation on the typical querying delay and derive a resource allocation rule to reduce the typical querying delay. we have a tendency to additional propose a distributed file replication protocol to appreciate the projected rule. intensive trace-driven experiments with synthesized traces and real traces show that our protocol are able to do shorter average querying delay at a lower value than current replication protocols

Tree bark scrape fungus: a potential source of laccase for application in bioremediation of non-textile dyes

Although laccase has been recognized as a wonder molecule and green enzyme, the use of low yielding fungal strains, poor production, purification, and low enzyme kinetics have hampered its large-scale application. Thus,this study aims to select high yielding fungal strains and optimize the production, purification, and kinetics of laccase of Aspergillus sp. HB-RZ4. The results obtained indicated that Aspergillus sp. HB-RZ4 produced a significantly large amount of laccase under meso-acidophilic shaking conditions in a medium containing glucose and yeast extract. A 25 μM CuSO4 was observed to enhance the enzyme yield. The enzyme was best purified on a Sephadex G-100 column. The purified enzyme resembled laccase of A. flavus. The kinetics of the purified enzyme revealed high substrate specificity and good velocity of reaction,using ABTS as a substrate. The enzyme was observed to be stable over various pH values and temperatures. The peptide structure of the purified enzyme was found to resemble laccase of A. kawachii IFO 4308. The fungus was observed to decolorize various dyes independent of the requirement of a laccase mediator system. Aspergillus sp. HB-RZ4 was observed to be a potent natural producer of laccase, and it decolorized the dyes even in the absence of a laccase mediator system. Thus, it can be used for bioremediation of effluent that contains non-textile dyes. © 2020 Sayyed et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

The Sandia Fracture Challenge: blind round robin predictions of ductile tearing

Existing and emerging methods in computational mechanics are rarely validated against problems with an unknown outcome. For this reason, Sandia National Laboratories, in partnership with US National Science Foundation and Naval Surface Warfare Center Carderock Division, launched a computational challenge in mid-summer, 2012. Researchers and engineers were invited to predict crack initiation and propagation in a simple but novel geometry fabricated from a common off-the-shelf commercial engineering alloy. The goal of this international Sandia Fracture Challenge was to benchmark the capabilities for the prediction of deformation and damage evolution associated with ductile tearing in structural metals, including physics models, computational methods, and numerical implementations currently available in the computational fracture community. Thirteen teams participated, reporting blind predictions for the outcome of the Challenge. The simulations and experiments were performed independently and kept confidential. The methods for fracture prediction taken by the thirteen teams ranged from very simple engineering calculations to complicated multiscale simulations. The wide variation in modeling results showed a striking lack of consistency across research groups in addressing problems of ductile fracture. While some methods were more successful than others, it is clear that the problem of ductile fracture prediction continues to be challenging. Specific areas of deficiency have been identified through this effort. Also, the effort has underscored the need for additional blind prediction-based assessments

INVESTIGATING SPRINGBACK OF SEAMLESS TUBES COLD DRAWING PROCESS USING DESIGN OF EXPERIMENTS (DOE) AND MICROSTRUCTURAL INVESTIGATIONS

Cold drawing is widely used manufacturing process for production of seamless tubes. Spring back is one the defect occurring in cold drawing process. A cold drawn tube will try to return to its original configurationupon removal of load. The phenomenon incurs due to an elastic recovery. This work is systematic investigations of optimized parameters to minimize springback viz., reduction ratio, die semi angle, land width and drawing speed through Design of Experimentsand microstructural investigations using X-Ray Diffraction, Scan Electron Microscopy and Metallurgical Microscope. The results of this study indicates that 10-15 % reduction ratio, 15 degree die semi angle,10 mm land width and 8 m/min drawing speed gives least springback for ST 52 tube material and AISI D3 die-plug material. This study has improved springback value significantly through series of experimentation and reduced the rejection by 3 % in precision tubes saving substantial amount of the cold drawing manufacturing industry

Efficient virtual network function placement strategies for Cloud Radio Access Networks

The new generation of 5G mobile services place stringent requirements for cellular network operators in terms of latency and costs. The latest trend in radio access networks (RANs) is to pool the baseband units (BBUs) of multiple radio base stations and to install them in a centralized infrastructure, such as a cloud, for statistical multiplexing gains. The technology is known as Cloud Radio Access Network (CRAN). Since cloud computing is gaining significant traction and virtualized data centers are becoming popular as a cost-effective infrastructure in the telecommunication industry, CRAN is being heralded as a candidate technology to meet the expectations of radio access networks for 5G. In CRANs, low energy base stations (BSs) are deployed over a small geographical location and are connected to a cloud via finite capacity backhaul links. Baseband processing unit (BBU) functions are implemented on the virtual machines (VMs) in the cloud over commodity hardware. Such functions, built in software, are termed as virtual functions (VFs). The optimized placement of VFs is necessary to reduce the total delays and minimize the overall costs to operate CRANs. Our study considers the problem of optimal VF placement over distributed virtual resources spread across multiple clouds, creating a centralized BBU cloud. We propose a combinatorial optimization model and the use of two heuristic approaches, which are, branch-and-bound (BnB) and simulated annealing (SA) for the proposed optimal placement. In addition, we propose enhancements to the standard BnB heuristic and compare the results with standard BnB and SA approaches. The proposed enhancements improve the quality of the solution in terms of latency and cost as well as reduce the execution complexity significantly. We also determine the optimal number of clouds, which need to be deployed so that the total links delays, as well as the service migration delays, are minimized, while the total cloud deployment cost is within the acceptable limits.This publication was made possible by the NPRP award [ NPRP 8-634-1-131 ] from the Qatar National Research Fund (a member of The Qatar Foundation) and NSF Grant CNS-1718929 . The statements made herein are solely the responsibility of the author[ s ]

Exploring microservices for enhancing internet QoS

With the enhancements in the field of software-defined networking and virtualization technologies, novel networking paradigms such as network function virtualization and the Internet of Things are rapidly gaining ground. The development of Internet of Things and 5G networks and explosion in online services has resulted in an exponential growth of devices connected to the network. As a result, application service providers and Internet service providers are being confronted with the unprecedented challenge of accommodating increasing service and traffic demands from the geographically distributed users. To tackle this problem, many and ISPs, such as Netflix, Facebook, and AT&T, are increasingly adopting microservices application architecture. Despite the success of microservices in the industry, there is no specific standard or research work for service providers as guidelines, especially from the perspective of basic microservice operations. In this work, we aim to bridge this gap between the industry and the academia and discuss different microservice deployment, discovery, and communication options for service providers as a means to forming complete service chains. In addition, we address the problem of scheduling microservices across multiple clouds, including microclouds. We consider different user-level service level agreements, such as latency and cost, while scheduling such services. We aim to reduce the overall turnaround time and costs for the deployment of complete end-to-end service. In this work, we present a novel affinity-based fair weighted scheduling heuristic to solve this problem. We also compare the results of the proposed solution with standard greedy scheduling algorithms presented in the literature and observe significant improvements.This publication was made possible by the National Priorities Research Program award [NPRP 8-634-1-131] from the Qatar National Research Fund (a member of The Qatar Foundation).Scopu