88,926 research outputs found
Towards Autonomic Service Provisioning Systems
This paper discusses our experience in building SPIRE, an autonomic system
for service provision. The architecture consists of a set of hosted Web
Services subject to QoS constraints, and a certain number of servers used to
run session-based traffic. Customers pay for having their jobs run, but require
in turn certain quality guarantees: there are different SLAs specifying charges
for running jobs and penalties for failing to meet promised performance
metrics. The system is driven by an utility function, aiming at optimizing the
average earned revenue per unit time. Demand and performance statistics are
collected, while traffic parameters are estimated in order to make dynamic
decisions concerning server allocation and admission control. Different utility
functions are introduced and a number of experiments aiming at testing their
performance are discussed. Results show that revenues can be dramatically
improved by imposing suitable conditions for accepting incoming traffic; the
proposed system performs well under different traffic settings, and it
successfully adapts to changes in the operating environment.Comment: 11 pages, 9 Figures,
http://www.wipo.int/pctdb/en/wo.jsp?WO=201002636
Correct and Control Complex IoT Systems: Evaluation of a Classification for System Anomalies
In practice there are deficiencies in precise interteam communications about
system anomalies to perform troubleshooting and postmortem analysis along
different teams operating complex IoT systems. We evaluate the quality in use
of an adaptation of IEEE Std. 1044-2009 with the objective to differentiate the
handling of fault detection and fault reaction from handling of defect and its
options for defect correction. We extended the scope of IEEE Std. 1044-2009
from anomalies related to software only to anomalies related to complex IoT
systems. To evaluate the quality in use of our classification a study was
conducted at Robert Bosch GmbH. We applied our adaptation to a postmortem
analysis of an IoT solution and evaluated the quality in use by conducting
interviews with three stakeholders. Our adaptation was effectively applied and
interteam communications as well as iterative and inductive learning for
product improvement were enhanced. Further training and practice are required.Comment: Submitted to QRS 2020 (IEEE Conference on Software Quality,
Reliability and Security
Connecting the World of Embedded Mobiles: The RIOT Approach to Ubiquitous Networking for the Internet of Things
The Internet of Things (IoT) is rapidly evolving based on low-power compliant
protocol standards that extend the Internet into the embedded world. Pioneering
implementations have proven it is feasible to inter-network very constrained
devices, but had to rely on peculiar cross-layered designs and offer a
minimalistic set of features. In the long run, however, professional use and
massive deployment of IoT devices require full-featured, cleanly composed, and
flexible network stacks.
This paper introduces the networking architecture that turns RIOT into a
powerful IoT system, to enable low-power wireless scenarios. RIOT networking
offers (i) a modular architecture with generic interfaces for plugging in
drivers, protocols, or entire stacks, (ii) support for multiple heterogeneous
interfaces and stacks that can concurrently operate, and (iii) GNRC, its
cleanly layered, recursively composed default network stack. We contribute an
in-depth analysis of the communication performance and resource efficiency of
RIOT, both on a micro-benchmarking level as well as by comparing IoT
communication across different platforms. Our findings show that, though it is
based on significantly different design trade-offs, the networking subsystem of
RIOT achieves a performance equivalent to that of Contiki and TinyOS, the two
operating systems which pioneered IoT software platforms
Network emulation focusing on QoS-Oriented satellite communication
This chapter proposes network emulation basics and a complete case study of QoS-oriented Satellite Communication
Market-Driven Management, Global Competition and Corporate Responsibility
The aim of the paper is to define the role of corporate responsibility in sustainable development of global firms. To be successful, global firms must be on the alert of emerging environmental trends and do their best to improve the corporate performance in line with key stakeholder expectations. In this respect, the management of corporate social responsibility highlights the criticality of the corporate intangible assets system and the need for overall assessment of corporate performance - not only financial performance but social too.Market-Driven Management; Corporate Responsibility; Corporate Social Responsibility; Intangible Assets; Global Markets
Teleoperation of passivity-based model reference robust control over the internet
This dissertation offers a survey of a known theoretical approach and novel experimental results in establishing a live communication medium through the internet to host a virtual communication environment for use in Passivity-Based Model Reference Robust Control systems with delays. The controller which is used as a carrier to support a robust communication between input-to-state stability is designed as a control strategy that passively compensates for position errors that arise during contact tasks and strives to achieve delay-independent stability for controlling of aircrafts or other mobile objects. Furthermore the controller is used for nonlinear systems, coordination of multiple agents, bilateral teleoperation, and collision avoidance thus maintaining a communication link with an upper bound of constant delay is crucial for robustness and stability of the overall system. For utilizing such framework an elucidation can be formulated by preparing site survey for analyzing not only the geographical distances separating the nodes in which the teleoperation will occur but also the communication parameters that define the virtual topography that the data will travel through. This survey will first define the feasibility of the overall operation since the teleoperation will be used to sustain a delay based controller over the internet thus obtaining a hypothetical upper bound for the delay via site survey is crucial not only for the communication system but also the delay is required for the design of the passivity-based model reference robust control. Following delay calculation and measurement via site survey, bandwidth tests for unidirectional and bidirectional communication is inspected to ensure that the speed is viable to maintain a real-time connection. Furthermore from obtaining the results it becomes crucial to measure the consistency of the delay throughout a sampled period to guarantee that the upper bound is not breached at any point within the communication to jeopardize the robustness of the controller. Following delay analysis a geographical and topological overview of the communication is also briefly examined via a trace-route to understand the underlying nodes and their contribution to the delay and round-trip consistency. To accommodate the communication channel for the controller the input and output data from both nodes need to be encapsulated within a transmission control protocol via a multithreaded design of a robust program within the C language. The program will construct a multithreaded client-server relationship in which the control data is transmitted. For added stability and higher level of security the channel is then encapsulated via an internet protocol security by utilizing a protocol suite for protecting the communication by authentication and encrypting each packet of the session using negotiation of cryptographic keys during each session
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