Jacek Rak

Bio: Jacek Rak is an academic researcher from Gdańsk University of Technology. The author has contributed to research in topics: Resilience (network) & Survivability. The author has an hindex of 15, co-authored 98 publications receiving 854 citations.

A survey of strategies for communication networks to protect against large-scale natural disasters

Abstract: Recent natural disasters have revealed that emergency networks presently cannot disseminate the necessary disaster information, making it difficult to deploy and coordinate relief operations These disasters have reinforced the knowledge that telecommunication networks constitute a critical infrastructure of our society, and the urgency in establishing protection mechanisms against disaster-based disruptions

Resilient Routing in Communication Networks

Abstract: Introduction Principles of Communication Networks Resilience Resilience of Future Internet Communications Resilience of Wireless Mesh Networks Disruption-tolerant Routing in Vehicular Ad-hoc Networks

LLA: A New Anypath Routing Scheme Providing Long Path Lifetime in VANETs

Abstract: Vehicular ad-hoc networks (VANETs) are a promising solution to improve the road traffic safety, reduce the environmental pollution, or simply provide the on-board infotainment services. However, these actions are often not possible due to high mobility of vehicles causing frequent failures of VANET links. In this paper, we focus on anypath routing to improve the reliability of multihop VANET communications. In particular, the paper is the first one to address the link stability \hbox{issues and to propose} a method called Long Lifetime Anypaths (LLA) providing stable communication paths. Advantages of our \hbox{approach}, presented in comparison to the reference Shortest Anypath First (SAF) scheme, are confirmed throughout simulations.

RECODIS: Resilient Communication Services Protecting End-user Applications from Disaster-based Failures

Abstract: Disaster-based failures can seriously disrupt any communication network, making its services unavailable. Such disruptions may be caused by natural disasters, technology-related failures, or malicious attacks, and they are observably increasing in number, intensity and scale. When network services that are a part of critical infrastructure become unavailable, commercial and/or societal problems are inevitable. The issue of limiting the impact of disaster-based failures needs to be urgently addressed due to the lack of suitable mechanisms deployed in the current networks.

Protection in elastic optical networks

Abstract: In this article, we analyze gains resulting from the use of EON architectures with special focus on transportation of cloud-ready and content-oriented traffic in the context of network resilience. EONs are a promising approach for future optical transport networks and, apart from improving the network spectral efficiency, bring such new capabilities as squeezed protection, which reduces resource requirements in failure scenarios. In the introductory part, we present a background on new network services based on cloud computing and content orientation paradigms, EON architectures, and their survivability mechanisms. Next, we show the impact of disasters on EON performance. To support the discussion, in the evaluation part we provide simulation results to compare survivable EONs and wavelength-switching optical networks, estimate the efficiency of different survivable EON schemes supporting cloud- and content-oriented traffic, and assess the robustness of EONs to disasters.

의사 간호사 communication

Abstract: The Communication program emphasizes theory, research, and application to examine the ways humans communicate, verbally and non-verbally, across a variety of levels and contexts. This is particularly important as communication shapes our ideas and values, gives rise to our politics, consumption and socialization, and helps to define our identities and realities. Its power and potential is inestimable. From the briefest of text messages to the grandest of public declarations, we indeed live within communication and invite you to join us in appreciating its increasing importance in contemporary society. From Twitter and reality television to family relationships and workplace dynamics, communication is about understanding ourselves, our media, our relationships, our culture and how these things connect.

Health-CPS: Healthcare Cyber-Physical System Assisted by Cloud and Big Data

Abstract: The advances in information technology have witnessed great progress on healthcare technologies in various domains nowadays. However, these new technologies have also made healthcare data not only much bigger but also much more difficult to handle and process. Moreover, because the data are created from a variety of devices within a short time span, the characteristics of these data are that they are stored in different formats and created quickly, which can, to a large extent, be regarded as a big data problem. To provide a more convenient service and environment of healthcare, this paper proposes a cyber-physical system for patient-centric healthcare applications and services, called Health-CPS, built on cloud and big data analytics technologies. This system consists of a data collection layer with a unified standard, a data management layer for distributed storage and parallel computing, and a data-oriented service layer. The results of this study show that the technologies of cloud and big data can be used to enhance the performance of the healthcare system so that humans can then enjoy various smart healthcare applications and services.

A Theory of Graphs

Abstract: A graph is just a bunch of points with lines between some of them, like a map of cities linked by roads. A rather simple notion. Nevertheless, the theory of graphs has broad and important applications, because so many things can be modeled by graphs. For example, planar graphs — graphs in which none of the lines cross are— important in designing computer chips and other electronic circuits. Also, various puzzles and games are solved easily if a little graph theory is applied.