Monte Carlo Simulation Models Evolving in Replicated Runs: A Methodology to Choose the Optimal Experimental Sample Size

The idea of a methodology capable of determining in a precise and practical way the optimal sample size came from studying Monte Carlo simulation models concerning financial problems, risk analysis, and supply chain forecasting. In these cases the number of extractions from the frequency distributions characterizing the model is inadequate or limited to just one, so it is necessary to replicate simulation runs many times in order to obtain a complete statistical description of the model variables. Generally, as shown in the literature, the sample size is fixed by the experimenter based on empirical assumptions without considering the impact on result accuracy in terms of tolerance interval. In this paper, the authors propose a methodology by means of which it is possible to graphically highlight the evolution of experimental error variance as a function of the sample size. Therefore, the experimenter can choose the best ratio between the experimental cost and the expected results

Modeling and Estimation of Thermal Flows Based on Transport and Balance Equations

Heat transfer in counterflow heat exchangers is modeled by using transport and balance equations with the temperatures of cold fluid, hot fluid, and metal pipe as state variables distributed along the entire pipe length. Using such models, boundary value problems can be solved to estimate the temperatures over all the length by means of measurements taken only at the boundaries. Conditions for the stability of the estimation error given by the difference between the temperatures and their estimates are established by using a Lyapunov approach. Toward this end, a method to construct nonlinear Lyapunov functionals is addressed by relying on a polynomial diagonal structure. This stability analysis is extended in case of the presence of bounded modeling uncertainty. The theoretical findings are illustrated with numerical results, which show the effectiveness of the proposed approach

Applications of Engineering 4.0 to Improve the Safety of Metalworking Operators: The Ansaldo Energia Case

The paper describes how, on behalf of Ansaldo Energia Spa, a multidisciplinary team developed a methodology based on Industry 4.0 technologies, an approach that allows rescue teams to quickly intervene in the event of a mandown in isolated areas of the plant, where the unfortunate person would risk being found with significant delay and onsequent problems for his physical well-being. Under the supervision of the team, a highly specialized supplier created a suitable hardware and software device to achieve this outcome. Such a device can immediately warn rescue crews in real time as soon as an incident occurs, as well as geo-locate the man on the ground with exceptional precision. Once developed, the approach was standardized in a set of sequential and generic procedures in order to make it adaptable to any sort of firm, construction site, or workshop where a man-down event may happen. The methodology is set up as a real toolkit to protect operators from severe damage that can result from long waits for rescue teams, whenever operators experience negative events for their safety being them exogenous (fainting illnesses, heart attacks, epileptic attacks, strokes, etc.) or endogenous (accidents in the workplace)

Using logistic redesigner (Lo.R.D.) software for designing and simulating a steel supply chain

This paper regards the analysis of the development of a logistics and transportation network concerning a steel plant. The main goal is to search for the best scenario that allows to supply the plant and to distribute all the finished products to final customers in the most efficient way. To this aim, a proper simulation model has been developed and implemented utilizing Logistics Re Designer (Lo. R. D.) software. More specifically, three different transportation networks have been created: two “single” modal choice scenarios - by road or by rail – and an “intermodal” one. Another system variable regards the production capacity of the steel plant: three different types of capacity have been considered; so in total nine scenarios have been taken into consideration. The results obtained indicate that the intermodal solution is the most suitable to be adopted both in terms of total time – and consequently costs - and resources required to perform all the necessary operations. Future research will focus on the improvement of the solution found and on the development of an economical analysis

Study of an emergency situation using 2D and 3D simulation models

Safety in motorway tunnels has become a critical issue in the last years, especially after the accident happened in 1999 inside the Mont Blanc tunnel, causing 39 deaths and several dozens of intoxications and wounded people. After this tragic event, the European Union imposed stricter regulations and procedures for emergency situations inside road tunnels longer than 1000 m. According to this situation, the authors propose the use of M&S (Modeling and Simulation) in order to manage a tunnel evacuation after a fire exploding in consequence to an accident, taking into account a series of significant factors like the road signs position (new criteria have been introduced with new regulation), but also human factors which significantly affect the procedure outcome. First a 2-D simulation model has been developed using Java™ Software, in which the user can analyze the behavior of the people escaping and the dynamics of the fire exploded and, consequently, assess the effectiveness of all the emergency procedures and infrastructures. In particular, regarding the state variables related to the human behavior, the model takes into account the main aspects of PECS (Physical Emotional Cognitive Social) reference models, in which physical, emotional, cognitive and social factors have to be studied. The model presented in this work is in fact quite similar to the one described by (Schmidt, 2000), called “Adam’s World” where Adam, a primitive man, lives in an environment having food sources where he can replenish his energy level, but also traps and danger points to be avoided in order not to consume his energy faster. The aim of the two models is the same: first of all preserve life and health, but the great difference between Schmidt’s model and the authors’ one is that in Adam’s World the social aspect is missing (Adam live alone in his world), while in the evacuation model social aspects can significantly affect the individual’s decisions. Upstream of the evacuation model, a weighted analysis needs to be considered, in fact the individual has to operate different choices considering several aspects, like health or goods preservation, familiar aspects, panic and so on. For this reason a suitable methodology has been detected: the Analytic Hierarchic Process (AHP), implemented by the American mathematician Thomas Saaty, which introduced this technique for Multi-Criteria Analysis. After the considerations on the individuals behavior based on the results of the analysis, the evacuation model and its results are described and analyzed in the following sections and, in the final part of the paper, a description of a 3-D tunnel model devoted to study in particular smoke dynamics is provided, thus it is possible to evaluate the impact of the smoke on the flow of the people escaping from the tunnel

A short review of the SDKs and wearable devices to be used for AR application for industrial working environment

During the last two decades, and especially the last few years, augmented reality helps workers manage safety risks on site and prevent injuries and increase the efficiency of safety. This review on the presently existing SDKs and their features is aimed at finding the most efficient AR SDK that would be suitable and would correspond to the purpose of the AR application for industrial working environment in terms of safety. The summarized information of the world\u2019s most widely used platforms for AR development, with support for leading phones, tablets and eyewear, SDKs presently available on the market is intended to help developers to create their AR application as well as to which parameters one should pay attention to, when building augmented reality applications for industrial use

Investigation about use of drone in a patrol purpose and applicability of this surveillance particularly to existing legislation

This article represents an effort to investigate the unmanned aerial vehicle (UAV) or \u2018drone\u2019 as patrolum service, bringing together its diverse forms, current and projected uses and legal challenges it raises, with a view to its large-scale capabilities for searching and identifying people. The relatively tight focus of contemporary recognition systems allows the use of this technology for searching of individuals. Now the degree of surveillance coverage in time and space that the UAV allows is having important effects, drones are increasingly being used in vast array of civilian and governmental situations. Application of drone\u2019s usage in public places increases the chance that individuals will come under scrutiny from faraway aircraft without knowing it; there is apprehension in the use of domestic drones due to several safety and privacy concerns. After the introduction, the paper describes the overall features of propagation of drone usage from military to civil purposes; then, in section 3 description of the airship solution is carried out. In the next section, legislative problems are determined for UAVs and the airship basing civilian airspace regulation. Finally, the conclusions of the study are drawn

Optimization Model of a Tandem Water Reservoir System Management

This paper presents a complex approach for modelling of a tandem reservoir systems for water drainage management. The model has been built over a segment of a river with a certain parameters of water inflow, water outflow, required power production and max possible flood occurrence. Then the segments may be replicated with specific parameters to simulate whole system of the river. The model has been optimized in order to obtain the water drainage operation policy with regards of current and expected water volumes in the reservoirs ratio, required power production revenue, and minimal flood occurrence. Model has been verified on a walkthrough basis. The obtained results demonstrate good reliability disregards broad possible variations of the managed parameters and provide the optimal water drainage for minimum flood occurrence and desired power production revenue

The Multi Crane Scheduling Problem: A Comparison Between Genetic Algorithm and Neural Network Approaches based on Simulation Modeling

The internal logistics for warehouses of many industrial applications, based on the movement of heavy goods, is commonly solved by the installment of a multi-crane system. The job scheduling of a multi-crane system is an interesting problem of optimization, solved in many ways in the past. This paper describes a comparison between the optimization by the use of Genetic Algorithms (GA) and introduce a framework for the solution of the problem using machine learning driven by Neural Networks (NN). Even though this last approach is not implemented in this paper, performances very close to GA ones are expected with NN. A case-study for steel coil production is proposed as a test frame for two different simulation software tools, one based on a heuristic solution and one on machine learning; performances and data achieved from reviews and simulations are compared