/pdf/a-break-in-the-clouds-towards-a-cloud-definition-svovsw1r5a.pdf

A Break in the Clouds: Towards a Cloud Definition

Many ``real-world'' networks are clearly defined while most ``social'' networks are to some extent subjective. Indeed, the accuracy of empirically-determined social networks is a question of some concern because individuals may have distinct perceptions of what constitutes a social link. One unambiguous type of connection is sexual contact. Here we analyze data on the sexual behavior of a random sample of individuals, and find that the cumulative distributions of the number of sexual partners during the twelve months prior to the survey decays as a power law with similar exponents $\alpha \approx 2.4$ for females and males. The scale-free nature of the web of human sexual contacts suggests that strategic interventions aimed at preventing the spread of sexually-transmitted diseases may be the most efficient approach.

The Web of Human Sexual Contacts

With the rapid development of wireless communication networks, it is expected that fourth-generation mobile systems will be launched within decades. 4G mobile systems focus on seamlessly integrating the existing wireless technologies including GSM, wireless LAN, and Bluetooth. This contrasts with 3G, which merely focuses on developing new standards and hardware. 4G systems supports comprehensive and personalized services, providing stable system performance and quality service. However, migrating current systems to 4G presents enormous challenges. In this article, these challenges are discussed under the headings of mobile station system, and service aspects. Proposed solutions to the research problems in each aspect are also examined.

Challenges in the migration to 4G mobile systems

Unmanned aerial vehicles (UAVs) can be used to serve as aerial base stations to enhance both the coverage and performance of communication networks in various scenarios, such as emergency communications and network access for remote areas. Mobile UAVs can establish communication links for ground users to deliver packets. However, UAVs have limited communication ranges and energy resources. Particularly, for a large region, they cannot cover the entire area all the time or keep flying for a long time. It is thus challenging to control a group of UAVs to achieve certain communication coverage in a long run, while preserving their connectivity and minimizing their energy consumption. Toward this end, we propose to leverage emerging deep reinforcement learning (DRL) for UAV control and present a novel and highly energy-efficient DRL-based method, which we call DRL-based energy-efficient control for coverage and connectivity (DRL-EC3). The proposed method 1) maximizes a novel energy efficiency function with joint consideration for communications coverage, fairness, energy consumption and connectivity; 2) learns the environment and its dynamics; and 3) makes decisions under the guidance of two powerful deep neural networks. We conduct extensive simulations for performance evaluation. Simulation results have shown that DRL-EC3 significantly and consistently outperform two commonly used baseline methods in terms of coverage, fairness, and energy consumption.

Energy-Efficient UAV Control for Effective and Fair Communication Coverage: A Deep Reinforcement Learning Approach

The logic of decision and action

Anomaly detection and predictive maintenance for photovoltaic systems

The paper discusses NetChaser, a mobile agent-based infrastructure for supporting personal mobility in accessing Internet information services. It exploits agents' ability to assist users by following them when they change working terminals.

NetChaser: agent support for personal mobility

A trust-aware, self-organizing system for large-scale federations of utility computing infrastructures

Finding the position of a mobile agent in a wide distributed system still represents an open research issue. The paper proposes a naming scheme and a location protocol of general validity for mobile agents able to effectively meet all the typical requirements of mobile agent environments and, thus, easy to integrate into different platforms. The paper identifies the main characteristics which an agent naming scheme and a location protocol of general validity should have, and suggests some properties and parameters to be taken into account to evaluate the effectiveness of naming schemes and location protocols. Then, we propose a "human readable" agent naming scheme based on the distributed environment outlined in MASIF, and a suitable location finding protocol called the Search-By-Path-Chase. Both of them are compared with some of the solutions already provided, using the properties and the parameters suggested. The performances are finally evaluated by means of a set of measurements.

Corrado Santoro

Papers

Anomaly detection and predictive maintenance for photovoltaic systems

NetChaser: agent support for personal mobility

A trust-aware, self-organizing system for large-scale federations of utility computing infrastructures

Locating mobile agents in a wide distributed environment

A Python framework for programming autonomous robots using a declarative approach