Search results for "Hard"
showing 10 items of 2294 documents
Situation Understanding for Operational Art in Cyber Operations
2016
This paper presents a theoretically motivated framework and methodology that has been designed for finding out the emergent phenomena and information needs for planning and decision-making. The approach is based on complexity thinking, system modeling, communication and cognition philosophy, social system theories and content analysis research technique. It provides results with the analysis of quite small sets of information. The paper demonstrates the approach with a case study. The study was performed in an international cyber experiment of the Multinational Capability Development Campaign (MCDC) 2013-2014. The case study shows that the proposed approach is plausible for increasing under…
DOUBLE EARTH FAULT EFFECTS IN PRESENCE OF INTERCONNECTED EARTH ELECTRODES
2009
The paper presents a study on the effects of double earth faults in Medium Voltage (MV) networks, in presence of electrical interconnection of the earthing systems of the secondary substations. In urban areas, indeed, the earth electrodes of the secondary substations are interconnected and, in many cases, they are also connected to the earth electrodes of the primary stations, in order to realize quasi-equipotential surfaces, intrinsically safe against electric shocks, named Global Earthing Systems (GES). The concept of GES has been introduced in the technical literature ten years ago in the Document HD 637 S1 by CENELEC, with the aim of providing a solution to the problems of designing and…
Latest advancements in manufacturing systems at NAMRC 45
2017
Latest manufacturing technologies are more prevalent thanbefore due to recent industrial revolution (or Industry 4.0), continu-ous business decentralization and needs for better overall resourceefficiency and effectiveness. Manufacturers are competing in aglobal, dynamic marketplace that demands excellence in qual-ity and service, throughput, innovativeness, agility in production,short response time to changing markets, and tight profitable mar-gins. In the 21 st century, manufacturing will be gradually pushedtowards a distributed environment with increasing dynamism oruncertainty. It is envisioned that Cyber-Physical Systems (CPS),Cloud Manufacturing, Internet of Things, and Big Data Analy…
Electrostatic synchronous generator model of an Inverter-Based Distributed Generators
2015
In this paper, the idea of modelling the Inverter-Based Distributed Generators by using the concept of Electrostatic synchronous machines is discussed. A mathematical model of the inverter has been established which depends on the dc bus voltage, modulation index and frequency of the system. Two mathematical models have been developed: a small signal model and a steady-state model. These mathematical models will be helpful in studying the stability of a microgrid; especially when studying the transient stability performance of on-grid operation of converter-based distributed generator with multi-machine microgrid. Simulation results using Matlab/Simulink are carried out.
Optimum design for work-hardening adaptation
1977
Abstract The finite element-linear programming approach and the work-hardening adaptation criterion are used to formulate a general theory of optimum design of rigid-work-hardening structures subjected to loads which vary statically within given limits. Self-weight, as well as some technological constraints, can be introduced into the framework of the optimization problem. The optimality conditions are discussed with the aid of geometrical descriptions as well, and a comparison is made with the standard limit design. Numerical applications are given for a plane truss and a plane frame with axial force-bending moment interaction.
A composite indicator for water meter replacement in an urban distribution network
2012
In water supply management, volumetric water meter are typically used to measure users' consumption. With water meters, utilities can collect useful data for billing, assess the water balance of the system, and identify failures in the network, water theft and anomalous user behaviour. Despite their importance, these instruments are characterised by intrinsic errors that cause so-called apparent losses. The complexity of the physical phenomena associated with metering errors in aging water meters does not allow meter replacement to be guided by single parameters, such as the meter age or the total volume passed through the meter. This paper presents a meter replacement strategy based on a c…
Cost benefits of flexible hybrid cloud storage : Mitigating volume variation with shorter acquisition cycle
2016
The hybrid cloud storage is investigated as a case of concurrent sourcing.The paper introduces an analytical model for hybrid cloud storage costs.We study the role of acquisition cycle and volume variation in hybrid cloud costs.Shortening the reassessment interval reduces the volume non-stationarity.Shortening the reassessment interval reduces the total hybrid costs. Hybrid cloud storage combines cost-effective but inflexible private storage along with flexible but premium-priced public cloud storage. As a form of concurrent sourcing, it offers flexibility and cost benefits to organizations by allowing them to operate at a cost-optimal scale and scope under demand volume uncertainty. Howeve…
Analysis of compressor architectures in MOS current-mode logic
2010
This paper is concerned with the design and the comparison of different compressor architectures for high performance multipliers in MOS current-mode logic (MCML). More specifically, three architectures have been designed for 3-2, 4-2 and 5-2 compressors and two architectures for 7-2 compressors. The various implementations for each type of compressor have been compared one another. This investigation indicates that the architectures based exclusively on three-level MCML gates are the most suitable for MCML implementation in terms of speed, power consumption and area. Design guidelines are provided to improve compressor performance. All the compressors were designed in a TSMC 180nm CMOS tec…
The "Livio Scarsi" X-Ray Facility at University of Palermo for Device Testing
2015
In this work, we report on the characteristics of the Livio Scarsi X-ray facility at University of Palermo. The facility is able to produce low energy X rays, within the energy range of 0.1-60 keV, with fluence rates ranging from 105-108 photons/mm2 s. The laboratory is equipped with an innovative digital detection system, based on semiconductor detectors (Si and CdTe detectors), able to provide accurate and precise estimation of the fluence rate, the energy and the exposure of X rays, even at high counting rate conditions. Instrumentation for electrical characterization (DC-AC) of semiconductor devices, for both off-line and on-line (i.e. during the irradiation) measurements, is also avail…
A mobile robot for vigilance tasks improved with a new robust and low cost communications system immune to attacks with EMI noise
2006
This work pretends to develop a robot for vigilance tasks that are able to tolerate diverse kinds of attacks and be able to operate in environments with elevated electromagnetic noise, being even immune to sabotage provoked by means of high electromagnetic fields. A new CAN based communications system that interconnects the different devices that compose the mobile robot has been developed to achieve this goal. The system is based on a shielded communications hub, that interconnects diverse nodes by means of CAN. On the other hand, the point to point communication between each node and the hub is carried out by means of economic optical fiber. With this approach all robot devices are connec…