Network recovery after massive failures

This paper addresses the problem of efficiently restoring sufficient resources in a communications network to support the demand of mission critical services after a large scale disruption. We give a formulation of the problem as an MILP and show that it is NP-hard. We propose a polynomial time heuristic, called Iterative Split and Prune (ISP) that decomposes the original problem recursively into smaller problems, until it determines the set of network components to be restored. We performed extensive simulations by varying the topologies, the demand intensity, the number of critical services, and the disruption model. Compared to several greedy approaches ISP performs better in terms of number of repaired components, and does not result in any demand loss. It performs very close to the optimal when the demand is low with respect to the supply network capacities, thanks to the ability of the algorithm to maximize sharing of repaired resources

On critical service recovery after massive network failures

This paper addresses the problem of efficiently restoring sufficient resources in a communications network to support the demand of mission critical services after a large-scale disruption. We give a formulation of the problem as a mixed integer linear programming and show that it is NP-hard. We propose a polynomial time heuristic, called iterative split and prune (ISP) that decomposes the original problem recursively into smaller problems, until it determines the set of network components to be restored. ISP's decisions are guided by the use of a new notion of demand-based centrality of nodes. We performed extensive simulations by varying the topologies, the demand intensity, the number of critical services, and the disruption model. Compared with several greedy approaches, ISP performs better in terms of total cost of repaired components, and does not result in any demand loss. It performs very close to the optimal when the demand is low with respect to the supply network capacities, thanks to the ability of the algorithm to maximize sharing of repaired resources

DEM modeling of rockfall rebound on protective embankments

Design of Rockfall Protection Embankments and estimation of their capacity to control the trajectory of rock boulders are complex issues, which give considerable room for research and improvement. A lack of detailed models for the simulation of block rebound in the embankment vicinity is mainly due to the large number of parameters that influences the phenomenon. Therefore, the evaluation of the embankment efficiency in satisfactorily acting on the block trajectory, as a function of the site characteristics and boulder kinematics, is still precluded to design engineers. In the present paper, the open-source code YADE, based on a discrete element method (DEM), is used to model the bouncing of a rock block on the embankment face, while taking into account a certain number of parameters with influence on the impact. By contrast with previously developed models (DEM, FEM or coupled approaches), the aim is here to propose a model with limited computation cost. In this purpose, the embankment is modelled as a membrane interacting with the rock block. The embankment body is not represented because it would require a large number of particles, and, consequently, a high computational time. Various elements implemented in YADE are used to model the embankment surface, with the aim of mimicking the mechanisms involved during the rock boulder rebound. The validity of the approach is addressed comparing simulation results with the few experimental data available from the literature. The influence of characteristics of the impacting block (radius and weight) and kinematic parameters (impact angle and velocity) on the restitution coefficients is explored. In particular, the normal (Rn), tangential (Rt) and energetic (RTE) coefficients of restitution are monitored. The goal of defining an efficient model in a realistic range of these parameters is pursued

The Future is Now

No abstract available DOI: http://dx.doi.org/10.5564/mjia.v0i5.361 The Mongolian Journal of International Affairs; Number 5, 1998, Pages 3-1

DEM MODELING OF ROCKFALL REBOUND ON PROTECTIVE EMBANKMENTS

Design of Rockfall Protection Embankments and estimation of their capacity to control the trajectory of rock boulders are complex issues, which give considerable room for research and improvement. A lack of detailed models for the simulation of block rebound in the embankment vicinity is mainly due to the large number of parameters that influences the phenomenon. Therefore, the evaluation of the embankment efficiency in satisfactorily acting on the block trajectory, as a function of the site characteristics and boulder kinematics, is still precluded to design engineers.In the present paper, the open-source code YADE, based on a discrete element method (DEM), is used to model the bouncing of a rock block on the embankment face, while taking into account a certain number of parameters with influence on the impact.By contrast with previously developed models (DEM, FEM or coupled approaches), the aim is here to propose a model with limited computation cost. In this purpose, the embankment is modelled as a membrane interacting with the rock block. The embankment body is not represented because it would require a large number of particles, and, consequently, a high computational time. Various elements implemented in YADE are used to model the embankment surface, with the aim of mimicking the mechanisms involved during the rock boulder rebound. The validity of the approach is addressed comparing simulation results with the few experimental data available from the literature. The influence of characteristics of the impacting block (radius and weight) and kinematic parameters (impact angle and velocity) on the restitution coefficients is explored. In particular, the normal (R-n), tangential (R-t) and energetic (R-TE) coefficients of restitution are monitored. The goal of defining an efficient model in a realistic range of these parameters is pursued

THE RISKS AND ADVANTAGES OF ANTI-DIABETES THERAPY IN THE POSITIVE COVID-19 PATIENT

The new Sars-Cov-2 (COVID-19) is causing thousands of deaths worldwide and has caused a global pandemic, one of the biggest health challenges ever faced in history. in the most severe cases, Sars-Cov-2 infection can cause fatal lung injuries. In this context, it is essential to recognise effective therapeutic agents against the virus. There are currently no direct and effective vaccines and antivirals available. People with pre-existing conditions, such as diabetes, and with chronic drug therapies in place may represent complex patients difficult to manage clinically during COVID-19 infection and at high risk of major complications. The regulation of blood glucose and the adoption of appropriate measures are critical aspects to consider for the diabetic patient in this pandemic period, especially in the patient with ongoing infection. In this article we describe the current evidence in the literature on the possible risks of side effects caused by taking antidiabetic drugs in the COVID-19 patient and the data on extra homeostasis glycemic activity useful to fight viral infection.              Peer Review History: Received 25 May 2020; Revised 8 June; Accepted 3 July, Available online 15 July 2020 Academic Editor: Essam Mohamed Eissa, Beni-Suef University, Egypt, [email protected] UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file:                Reviewer's Comments: Average Peer review marks at initial stage: 5.5/10 Average Peer review marks at publication stage: 7.0/10 Reviewer(s) detail: Dr. Heba M. Abd El-Azim, Damanhour University, Egypt, [email protected] Dr. George Zhu, Tehran University of Medical Sciences, Tehran, Iran, [email protected] Similar Articles: THE RELATIONSHIP BETWEEN DIABETES MELLITUS AND TUBERCULOSIS IN REVIEW OF PREVALENCE, DIAGNOSTICS AND PREVENTIO

USE OF COLCHICINE TO COUNTERACT THE STRONG HYPERINFLAMMATORY STATE INDUCED BY SARS-COV-2

Research in present time has been focusing on finding a specific SARS-CoV-2 vaccine or antiviral, which will probably be the therapeutic goal in the fight against the virus. In the meantime, scientific evidence shows that it is possible to have effective clinical improvements of infected patients in reducing the strong hyperinflammatory state. The SARS-CoV-2 infection is divided into three stages. The most serious phase is the third one where the immune system overdrives and launches an intense attack against itself. This is called "cytokine storm" and leads to tissue damage and often to death. Stopping the cytokine storm early is definitely an effective move; since March several studies have been evaluating how this can be an important pharmacological aspect. Blocking IL-6 or IL-1 inhibitors, for example, is already known to have wide efficacy, but they are not alone in being able to block the cascade of cytokines. This is a clinical pharmacology article and demonstrates how the use of colchicine, monotherapy or in combination in all three phases of SARS-CoV-2, controls inflammation and prevents patient death. Colchicine is safe and effective for treating SARS-CoV-2 patients in preventing inflammation and lung collapse and is certainly useful as an added remedy for other drugs. The advantage is certainly its safety profile much higher than that provided by other drugs, such as corticosteroids and immunosuppressive drugs. Note is the story of hydroxychloroquine: use has been banned due to its high toxicity.                               Peer Review History: Received 25 May 2020; Revised 10 June; Accepted 6 July, Available online 15 July 2020 Academic Editor: Dr. Muhammad Zahid Iqbal, AIMST University, Malaysia, [email protected] UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file:                Reviewer's Comments: Average Peer review marks at initial stage: 5.5/10 Average Peer review marks at publication stage: 7.0/10 Reviewer(s) detail: Dr. Jennifer Audu-Peter, University of Jos, Nigeria, [email protected] Dr. Robert Tungadi, State University of Gorontalo, Indonesia, [email protected]

Improved Methods of Task Assignment and Resource Allocation with Preemption in Edge Computing Systems

Edge computing has become a very popular service that enables mobile devices to run complex tasks with the help of network-based computing resources. However, edge clouds are often resource-constrained, which makes resource allocation a challenging issue. In addition, edge cloud servers must make allocation decisions with only limited information available, since the arrival of future client tasks might be impossible to predict, and the states and behavior of neighboring servers might be obscured. We focus on a distributed resource allocation method in which servers operate independently and do not communicate with each other, but interact with clients (tasks) to make allocation decisions. We follow a two-round bidding approach to assign tasks to edge cloud servers, and servers are allowed to preempt previous tasks to allocate more useful ones. We evaluate the performance of our system using realistic simulations and real-world trace data from a high-performance computing cluster. Results show that our heuristic improves system-wide performance by $20-25\%$ over previous work when accounting for the time taken by each approach. In this way, an ideal trade-off between performance and speed is achieved.Comment: 13 pages,added IEEE disclaime

A truthful online mechanism for resource allocation in fog computing

Fog computing is a promising Internet of Things (IoT) paradigm in which data is processed near its source. Here, efficient resource allocation mechanisms are needed to assign limited fog resources to competing IoT tasks. To this end, we consider two challenges: (1) near-optimal resource allocation in a fog computing system; (2) incentivising self-interested fog users to report their tasks truthfully. To address these challenges, we develop a truthful online resource allocation mechanism called flexible online greedy. The key idea is that the mechanism only commits a certain amount of computational resources to a task when it arrives. However, when and where to allocate resources stays flexible until the completion of the task. We compare our mechanism to four benchmarks and show that it outperforms all of them in terms of social welfare by up to 10% and achieves a social welfare of about 90% of the offline optimal upper bound

Rainfall-triggered debris flows: Triggering-propagation modelling and application to an event in Southern Italy

Debris flows are high-speed and unpredictable phenomena, considered among the main sources of hazard worldwide, since they can affect structures, the economy, and human lives. Rainfall typically triggers these events, causing the flowing of the unconsolidated soil downslope. This work focuses on debris-flow events characterized by multiple triggering areas, which are extremely complex since they involve a spatial sequence of numerous triggers in a relatively small portion of the slope. Numerical modelling of this type of phenomenon can contribute to hazard and risk assessment, which is key to designing effective mitigation structures. In this article, two different models are applied for triggering and propagation, respectively. The former computes the transient pore-pressure changes and the consequent factor of safety variation caused by rainfall infiltration, inducing the triggering of the event. The latter is a depth-averaged numerical model that simulates the event runout, and whose parameters are calibrated through back-analysis. The applicability of the two combined approaches is tested through modelling of an historical event in Southern Italy, which was characterized by large mass releases from multiple triggering zones. Residential areas were hit, suffering serious consequences. Two rheologies are compared to individuate the most suitable propagation model for the study case and obtained results are commented