Optimal Content Downloading in Vehicular Networks

We consider a system where users aboard communication-enabled vehicles are interested in downloading different contents from Internet-based servers. This scenario captures many of the infotainment services that vehicular communication is envisioned to enable, including news reporting, navigation maps and software updating, or multimedia file downloading. In this paper, we outline the performance limits of such a vehicular content downloading system by modelling the downloading process as an optimization problem, and maximizing the overall system throughput. Our approach allows us to investigate the impact of different factors, such as the roadside infrastructure deployment, the vehicle-to-vehicle relaying, and the penetration rate of the communication technology, even in presence of large instances of the problem. Results highlight the existence of two operational regimes at different penetration rates and the importance of an efficient, yet 2-hop constrained, vehicle-to-vehicle relaying

Risk mitigation decisions for it security

Enterprises must manage their information risk as part of their larger operational risk management program. Managers must choose how to control for such information risk. This article defines the flow risk reduction problem and presents a formal model using a workflow framework. Three different control placement methods are introduced to solve the problem, and a comparative analysis is presented using a robust test set of 162 simulations. One year of simulated attacks is used to validate the quality of the solutions. We find that the math programming control placement method yields substantial improvements in terms of risk reduction and risk reduction on investment when compared to heuristics that would typically be used by managers to solve the problem. The contribution of this research is to provide managers with methods to substantially reduce information and security risks, while obtaining significantly better returns on their security investments. By using a workflow approach to control placement, which guides the manager to examine the entire infrastructure in a holistic manner, this research is unique in that it enables information risk to be examined strategically. © 2014 ACM

Automated Network Service Scaling in NFV: Concepts, Mechanisms and Scaling Workflow

Next-generation systems are anticipated to be digital platforms supporting innovative services with rapidly changing traffic patterns. To cope with this dynamicity in a cost-efficient manner, operators need advanced service management capabilities such as those provided by NFV. NFV enables operators to scale network services with higher granularity and agility than today. For this end, automation is key. In search of this automation, the European Telecommunications Standards Institute (ETSI) has defined a reference NFV framework that make use of model-driven templates called Network Service Descriptors (NSDs) to operate network services through their lifecycle. For the scaling operation, an NSD defines a discrete set of instantiation levels among which a network service instance can be resized throughout its lifecycle. Thus, the design of these levels is key for ensuring an effective scaling. In this article, we provide an overview of the automation of the network service scaling operation in NFV, addressing the options and boundaries introduced by ETSI normative specifications. We start by providing a description of the NSD structure, focusing on how instantiation levels are constructed. For illustrative purposes, we propose an NSD for a representative NS. This NSD includes different instantiation levels that enable different ways to automatically scale this NS. Then, we show the different scaling procedures the NFV framework has available, and how it may automate their triggering. Finally, we propose an ETSI-compliant workflow to describe in detail a representative scaling procedure. This workflow clarifies the interactions and information exchanges between the functional blocks in the NFV framework when performing the scaling operation.Comment: This work has been accepted for publication in the IEEE Communications Magazin

Cost studies for commercial fuselage crown designs

Studies were conducted to evaluate the cost and weight potential of advanced composite design concepts in the crown region of a commercial transport. Two designs from each of three design families were developed using an integrated design-build team. A range of design concepts and manufacturing processes were included to allow isolation and comparison of cost centers. Detailed manufacturing/assembly plans were developed as the basis for cost estimates. Each of the six designs was found to have advantages over the 1995 aluminum benchmark in cost and weight trade studies. Large quadrant panels and cobonded frames were found to save significant assembly labor costs. Comparisons of high- and intermediate-performance fiber systems were made for skin and stringer applications. Advanced tow placement was found to be an efficient process for skin lay up. Further analysis revealed attractive processes for stringers and frames. Optimized designs were informally developed for each design family, combining the most attractive concepts and processes within that family. A single optimized design was selected as the most promising, and the potential for further optimization was estimated. Technical issues and barriers were identified

Devising a non-standard convertible zero-coupon bond to enhance corporate governance

This research paper brings forward a non-standard convertible zero-coupon bond endowed with a set of distinctive features attached to it so as to strengthen the corporate governance of the issuer, namely that conversion actually takes place at maturity date only; that conversion is mandatory; it offers investors a pay-off function tailored to match the conversion; there is no call provision whatsoever; it is suitable for private or public placements; credit-risk rating is of the essence and, lastly, it requires from the company a track record statement on behalf of investors. Although this sort of bond actually provides the company with a powerful financing vehicle, we argue that it could also play a constructive role if it were used in compensation packages for rewarding both senior managers and the Board of Directors.zero-coupon bond, convertible bond, corporate governance, covenants, compensation packages, track record statement

The role of presentation format on decision-makers' behaviour in accounting

The recent increase in researching presentation format area is resulting in an increase in awareness of the importance of presentation format on decision-makers' behaviour. This paper presents a synthesis of prior research on presentation format in the accounting literature which could be used as bases and references for future research. It reviews and evaluates existing accounting literature that examines the linkages of presentation format on decision-makers behaviour. Finally, future research opportunities in this area are made

Corporate finance in international perspective: legal and regulatory influences on financial system development

In the postwar period, systems of corporate finance and governance have emerged in the United States, Japan, and Germany that are dramatically different from one another. To date, there has been little focus on why. Stephen Prowse argues that differences in three aspects of the legal and regulatory environments in these countries are responsible. First, the severity of legal and regulatory restraints on financial institutions being "active" investors in firms. Second, the degree to which corporate securities markets are suppressed by regulation. Finally, the degree to which securities markets are "passively" suppressed by the absence of mandated disclosure requirements. ; Prowse compares the merits of each system and argues that the U.S. system may be more favorable to the growth of high-technology firms. He discusses the future evolution of each system. The German and Japanese regulatory environments are changing rapidly to increase the role of securities markets in corporate finance. The U.S. environment is also changing to give financial institutions more latitude to be active investors in firms. Over the long term, the regulatory environments of all three countries appear to be converging. The focal point of this convergence is an entirely new environment in which financial institutions are free to be active investors and corporate securities markets are unhindered by regulatory obstacles.Corporations - Finance ; International finance