Search results for "oftware"
showing 10 items of 7396 documents
Multiobjective optimization and decision making in engineering sciences
2021
AbstractReal-world decision making problems in various fields including engineering sciences are becoming ever more challenging to address. The consideration of various competing criteria related to, for example, business, technical, workforce, safety and environmental aspects increases the complexity of decision making and leads to problems that feature multiple competing criteria. A key challenge in such problems is the identification of the most preferred trade-off solution(s) with respect to the competing criteria. Therefore, the effective combination of data, skills, and advanced engineering and management technologies is becoming a key asset to a company urging the need to rethink how…
A dynamic life-cycle model for the provisioning of software testing services
2014
Information and communications technology (ICT)-enabled international sourcing of software-intensive systems and services (eSourcing) is a powerful strategy for managing businesses more effectively. China is becoming a superpower for eSourcing service provisioning, but most Chinese providers are small- or medium-sized and leverage the mediated eSourcing model, delivering services to foreign ICT clients who interface with end-clients onshore. This model restricts the providers to low-value projects. This paper probes eSourcing of software testing services within the Chinese market because testing is one of the best ICT services small- and medium-sized providers can provide to develop domain …
A Short-Term Data Based Water Consumption Prediction Approach
2019
A smart water network consists of a large number of devices that measure a wide range of parameters present in distribution networks in an automatic and continuous way. Among these data, you can find the flow, pressure, or totalizer measurements that, when processed with appropriate algorithms, allow for leakage detection at an early stage. These algorithms are mainly based on water demand forecasting. Different approaches for the prediction of water demand are available in the literature. Although they present successful results at different levels, they have two main drawbacks: the inclusion of several seasonalities is quite cumbersome, and the fitting horizons are not very large. With th…
A new control parameter to predict micro-warping-induced job failure in LPBF of TI6AL4V titanium alloy
2023
Abstract Laser powder bed fusion (LPBF) includes a few printing techniques widely used, in recent years, concerning the additive manufacturing of Ti6Al4V alloys. These produced parts, typically utilized in sectors such as aerospace and biomedical, are characterized by very high added value. It is therefore fundamental to identify the influence of process parameters typical of LPBF technology on the occurrence of warping leading to process failure. This study deals with the characterization of single-track and “micro-scale” level warping phenomena which may lead to protrusion of material over the powder bed and process failure before normal termination. This phenomenon was investigated as a …
A novel approach to enhance mechanical properties during recycling of aluminum alloy scrap through friction stir consolidation
2021
Solid state recycling (SSR) is a new approach for making metals recycling more efficient with respect to remelting-based approaches. Friction stir consolidation (FSC) is a new solid-state process that is employed to recycle metallic scraps. Until now, a single-step FSC process was applied to recycled metal chips. During the single-step approach, critical processes parameters, especially processing time and rotational speed, are considered vital to control the quality and mechanical properties of the billet. However, the effectiveness of process parameters is highly restricted by challenging masses of recycling chips and machine competency. The present study first highlights the issues of th…
RMS Based Health Indicators for Remaining Useful Lifetime Estimation of Bearings
2022
Estimating the remaining useful life (RUL) of bearings from healthy to faulty is important for predictive maintenance. The bearing fault severity can be estimated based on the energy or root mean square (RMS) of vibration signals, and a stopping criterion can be set based on a threshold given by an ISO standard. However, the vibration RMS is often not monotonically increasing with damage, which renders a challenge for predicting the RUL. This study proposes a novel method for splitting the vibration signal into multiple frequency bands before RMS calculations to generate multiple health indicators. Monotonic health indicators are identified using the Spearman coefficient, and the RUL is aft…
Control Flow Error Checking with ISIS
2005
The Interleaved Signature Instruction Stream (ISIS) is a signature embedding technique that allows signatures to co-exist with the main processor instruction stream with a minimal impact on processor performance, without sacrificing error detection coverage or latency. While ISIS incorporate some novel error detection mechanisms to assess the integrity of the program executed by the main processor, the limited number of bits available in the signature control word question if the detection mechanisms are effective detecting errors in the program execution flow. Increasing the signature size would negatively impact the memory requirements, so this option has been rejected. The effectiveness …
PLC security and critical infrastructure protection
2013
Programmable Logic Controllers (PLCs) are the most important components embedded in Industrial Control Systems (ICSs). ICSs have achieved highest standards in terms of efficiency and performance. As a result of that, higher portion of infrastructure in industries has been automated for the comfort of human beings. Therefore, protection of such systems is crucial. It is important to investigate the vulnerabilities of ICSs in order to solve the threats and attacks against critical infrastructure to protect human lives and assets. PLC is the basic building block of an ICS. If PLCs are exploited, overall system will be exposed to the threat. Many believed that PLCs are secured devices due to it…
Experimental System Identification and Black Box Modeling of Hydraulic Directional Control Valve
2015
Directional control valves play a large role in most hydraulic systems. When modeling the hydraulic systems, it is important that both the steady state and dynamic characteristics of the valves are modeled correctly to reproduce the dynamic characteristics of the entire system. In this paper, a proportional valve (Brevini HPV 41) is investigated to identify its dynamic and steady state characteristics. The steady state characteristics are identified by experimental flow curves. The dynamics are determined through frequency response analysis and identified using several transfer functions. The paper also presents a simulation model of the valve describing both steady state and dynamic charac…
Analysis of Offshore Knuckle Boom Crane - Part Two: Motion Control
2013
In this paper design of electro-hydraulic motion control systems for offshore knuckle boom cranes is discussed. The influence of the control valve bandwidth along with the ramp time for the control signal are investigated both analytically with simplified system models and numerically with an experimentally verified crane model. The results of both types of investigations are related to general design rules for selection of control valves and ramp times and the relevance of these design rules is discussed. Generally, they are useful but may be too conservative for offshore knuckle boom cranes. However, as demonstrated in the paper, the only proper way to determine this is to evaluate the mo…