Engineering Commons^™

Process Modelling Support For The Conceptual Modelling Phase Of A Simulation Project, Cathal Heavey, John Ryan

Conference papers

While many developments have taken place around supporting the model coding task of simulation, there are few tools available to assist in the conceptual modelling phase. Several authors have reported the advantages of using process modelling tools in the early phases of a simulation project.

This paper provides an overview of process modelling tools in relation to their support for simulation, categorizing the tools into formal method and descriptive methods. A conclusion from this review is that none of the tools available adequately support the requirements gathering phase of simulation. This is not surprising as none of the process modelling …

Impact Resistance Of Reinforced Concrete Columns: Experimental Studies And Design Considerations, Alexander Remennikov, Sakdirat Kaewunruen

Faculty of Engineering - Papers (Archive)

There are instances where reinforced concrete structures designed for static loads are subjected to accidental or deliberate impact or blast loads because of industrial or transportation accidents, military or terrorist activities. Analysis and design of structures for such events require realistic assessment of the ulti-mate impact resistance and a mode of failure of the structure. In this paper, a series of falling weight impact tests on conventionally designed reinforced concrete columns are described. The behaviour of quarter-scale reinforced concrete columns under static and impact loads is presented. An impact load was applied at the mid-height of the columns by a …

Robust Control Techniques Enabling Duty Cycle Experiments Utilizing A 6-Dof Crewstation Motion Base, A Full Scale Combat Hybrid Electric Power System, And Long Distance Internet Communications, Marc Compere, Jarrett Goodell, Miguel Simon, Wilford Smith, Mark Brudnak

Publications

The RemoteLink effort supports the U.S. Army's objective for developing and fielding next generation hybrid-electric combat vehicles. It is a distributed soldierin- the-Ioop and hardware-in-the-Ioop environment with a 6-DOF motion base for operator realism, a full-scale combat hybrid electric power system, and an operational context provided by OneSAF. The driver/gunner crewstations rest on one of two 6-DOF motion bases at the U.S. Army TARDEC Simulation Laboratory (TSL). The hybrid power system is located 2,450 miles away at the TARDEC Power and Energy System Integration Laboratory (P&E SIL). The primary technical challenge in the RemoteLink is to operate both laboratories together …

Comparison Of Solar Hot Water Systems Simulated In Energygauge Usa And Trnsys 15, Florida Solar Energy Center, Michael Anello

FSEC Energy Research Center®

This document is meant to serve as a detailed summary of the comparison between the simulation methods of EnergyGauge USA and TRNSYS (version 15) relating to solar hot water systems. The initial motivation behind this comparison was to verify that the f-chart model created for EnergyGauge's solar hot water calculations was reporting the correct results. To this end, models of three systems were created in TRNSYS in order to serve as a baseline for the EnergyGauge results. The three systems modeled were: Liquid-active closed loop (LACL), Liquid-active open loop (LAOL), Integrated collector storage (ICS). This document will detail each of …

Energy Efficient Renovations Of Storm Damaged Residences - Florida Case Studies, Florida Solar Energy Center, Neil Moyer

FSEC Energy Research Center®

Storm-damaged homes offer the opportunity for repairs that reduce energy use, improve comfort and enhance resistance to future storms. Case studies of four Florida homes damaged in the summer of 2004 were documented to show the costs and benefits of various retrofit strategies. All four homes required roof replacement and each took advantage of roof cladding with higher reflectance than the original, a proven means of reducing cooling energy use. Two of the case studies included improvements to attic insulation, tightening of the envelope and/or duct system and improved efficiency equipment and lighting. Energy savings attributable to storm repairs were …

Modeling Liquid-Crystal Devices With The Three-Dimensional Full-Vector Beam Propagation Method, Qian Wang, Gerald Farrell, Yuliya Semenova

Articles

Simulation of light propagation within nematic liquid-crystal (LC) devices is considered, of which the director is aligned normal to the z axis. A three-dimensional full-vector finite-difference beam propagation method for an anisotropic medium is presented and an alternating direction implicit scheme is adopted. Simulations of light propagation in a bulk polarization converter, a waveguide with a LC covering layer, and an integrated polarization splitter and optical switch are presented. Comparison with an existing simulation method is carried out for beam behavior within the bulk polarization converter. The effect of strong surface anchoring of a LC cell on the beam behaviors …

Simulation And Modeling Of Return Waveforms From A Ladar Beam Footprint In Usu Ladarsim, Scott E. Budge, B.C. Leishman, R.T. Pack

Electrical and Computer Engineering Faculty Publications

Ladar systems are an emerging technology with applications in many fields. Consequently, simulations for these systems have become a valuable tool in the improvement of existing systems and the development of new ones. This paper discusses the theory and issues involved in reliably modeling the return waveform of a ladar beam footprint in the Utah State University LadarSIM simulation software. Emphasis is placed on modeling system-level effects that allow an investigation of engineering tradeoffs in preliminary designs, and validation of behaviors in fabricated designs. Efforts have been made to decrease the necessary computation time while still maintaining a usable model. …

Steady State Simulations Of A Mars Entry Vehicle, Daniel Guy Schauerhamer

Undergraduate Honors Capstone Projects

Using computational fluid dynamics, steady state simulations of a capsule like Mars entry vehicle at certain trajectory points was performed. Trajectory points were chosen incrementally from 90 to 11.5 kilometers altitude. The Direct Simulation Monte Carlo method and the Overflow 2 Navier-Stokes solver were used depending on Knudsen number values greater than or less than 0.1, respectively. To compare flow effects of the maximum angle of attack error margin of three degrees, axially symmetric cases were computed and compared to three dimensional cases demonstrating an attack angle (α) of three degrees. Lift and drag coefficients are reported and compared. The …

Analysis Of Technical Energy Losses By Using Simulation, Betrianis Betrianis, Randite Herawan

Makara Journal of Technology

Model is a representation of a system. Through model, it can be easier to forecast and control the changing of each element system. Electricity distribution is also a system. Losses are general problem that exist in a distribution network system. But with the right methods, specifically technical energy losses can be reduced in order to increase the efficiency. By making model of the distribution network, the value of technical energy losses in the whole network as well as in every line can be observed. Simulation can also be used to see all losses reduction alternatives. By comparing results from each …

Parallel Simulated Annealing For Scheduling Agile Manufacturing Systems, Ahmed Osama Abdulrahman

Archived Theses and Dissertations

The problem addressed in this research is the scheduling of an agile manufacturing system comprised of machining and assembly operations with the objective of minimizing the makespan. This problem has been addressed in the literature using heuristics and metaheuristics. In addition, a lower bound has been developed. This research builds upon the findings of the recent literature and proposes two enhanced algorithms, parallel simulated annealing and parallel modified simulated annealing, to solve the addressed problem. The performance of the developed algorithms is compared to that of another simulated annealing algorithm that is available in the literature. Performance comparisons are based …

Patterns In Team Communication During A Simulation Game, David M. Baca, Ray Luechtefeld, Steve Eugene Watkins

Engineering Management and Systems Engineering Faculty Research & Creative Works

The development of communication skills is a necessary preparation for effective engineering teamwork. Argyris' "Theory of Action" provides a framework for understanding patterns in team dialogue. Students can benefit from an awareness of these patterns. The theory highlights the detection and correction of errors by sharing information during group collaboration and interactions. Quality decision-making can be enhanced when members of a team develop high degrees of openness and interdependence. Quality decision-making can be diminished when members of a team regulate the information shared within the team. This work analyzes team interactions from simulation games used in an interdisciplinary engineering course …

Anywhere, Anytime, Anysize, Any Signal: Scalable Remote Information Sensing And Communication Systems, George Markowsky

University of Maine Office of Research Administration: Grant Reports

Several recent meetings have highlighted the growing interest in the biological, ecological, environmental, and other research communities in the development and deployment of large distributed systems for information collection, aggregation, analysis, simulation, predictive modeling and realtime analysis within their respective disciplines. Likewise, recent events have caused concern and raised interest in the need for similar systems in the context of homeland security. It seems apparent that a structured discussion of the needs for these systems could create opportunities for synergistic efficiencies between the various user communities. To date, however, no such discussions have been held among these differing user communities, …

Dynamic Modeling Of Microclimate And Environmental Control Strategies In A Greenhouse Coupled With A Heat Pump System, Ilhami Yildiz, D. P. Stombaugh

BioResource and Agricultural Engineering

The purpose of this study was to develop and validate a dynamic simulation model to be employed in accurate prediction of microclimate in a greenhouse as a function of dynamic environmental factors. The model has options to evaluate the effects of location, time of the year, orientation, single and double polyethylene glazings, conventional and heat pump heating and cooling systems, open and confined greenhouse systems, CO₂ enrichment, variable shading, and the use of night curtains. Conventional gas furnace and evaporative cooling, respectively, provided heating and cooling in the conventional system. In the heat pump systems, gas-fired heat pump units …

Simulated Performances Of A Heat Pump System For Energy And Water Conservation In Open And Confined Greenhouse Systems, Ilhami Yildiz, D. P. Stombaugh

BioResource and Agricultural Engineering

The purpose of this study was to determine and compare the performances of conventional and heat pump systems for energy and water conservation in open and confined greenhouse systems. Conventional gas furnaces and evaporative cooling, respectively, provided heating and cooling in the conventional system. In the heat pump systems, gas-fired heat pump units provided both heating and cooling. The greenhouse with heat pump units also had an option to be operated as a completely confined system, using one of the heat pump units as a dehumidifier. Average energy consumption in winter was 56.9, 23.5, and 11.3 MJ/day.m² in the conventional, …

The Use Of Pc Based Simulation Systems In The Training Of Army Infantry Officers - An Evaluation Of The Rapid Decision Trainer, Thomas Lucario

Electronic Theses and Dissertations

This research considers two modes of training Army infantry officers in initial training to conduct a platoon live fire exercise. Leaders from groups that were training with the current classroom training methods were compared to leaders from groups whose training was augmented with a PC based training system known as the Rapid Decision Trainer (RDT). The RDT was developed by the US Army Research Development and Engineering Command for the purpose of aiding in the training of tactical decision making and troop leading procedures of officers in the initial levels of training to become rifle platoon leaders. The RDT allows …

A Holistic Usability Framework For Distributed Simulation Systems, Jeffrey Dawson

Electronic Theses and Dissertations

This dissertation develops a holistic usability framework for distributed simulation systems (DSSs). The framework is developed considering relevant research in human-computer interaction, computer science, technical writing, engineering, management, and psychology. The methodology used consists of three steps: (1) framework development, (2) surveys of users to validate and refine the framework, and to determine attribute weights, and (3) application of the framework to two real-world systems. The concept of a holistic usability framework for DSSs arose during a project to improve the usability of the Virtual Test Bed, a prototypical DSS, and the framework is partly a result of that project. …

Effect Of Operator Control Configuration On Unmanned Aerial System Trainability, John Neumann

Electronic Theses and Dissertations

Unmanned aerial systems (UAS) carry no pilot on board, yet they still require live operators to handle critical functions such as mission planning and execution. Humans also interpret the sensor information provided by these platforms. This applies to all classes of unmanned aerial vehicles (UAV's), including the smaller portable systems used for gathering real-time reconnaissance during military operations in urban terrain. The need to quickly and reliably train soldiers to control small UAS operations demands that the human-system interface be intuitive and easy to master. In this study, participants completed a series of tests of spatial ability and were then …

Digital Controller Implementation For Disturbance Rejection In The Optical Coupling Of A Mobile Experimental Laser Tracking Systems, Matthew Rhodes

Electronic Theses and Dissertations

Laser tracking systems are an important aspect of the NASA space program, in particular for conducting research in relation to satellites and space port launch vehicles. Often, launches are conducted at remote sites which require all of the test equipment, including the laser tracking systems, to be portable. Portable systems are more susceptible to environmental disturbances which affect the overall tracking resolution, and consequently, the resolution of any other experimental data being collected at any given time. This research characterizes the optical coupling between two systems in a Mobile Experimental Laser Tracking system and evaluates several control solutions to minimize …

Developing Microscopic Toll Plaza Model Using Paramics, Nezamuddin Nezamuddin

Electronic Theses and Dissertations

Simulation modeling is the most cost-effective way of studying real life transportation problems, either existing or anticipated, without disturbing the balance of the transportation system. There is a vast suite of simulation models available in market, ready to choose from macroscopic, mesoscopic, or microscopic in nature, to study different transportation system elements like freeways, highways, signalized and un-signalized intersections. However, most of these network simulation models, like PARAMICS, VISSIM, CORSIM … etc, do not come readily available with built in toll plaza models. On the other hand, many researchers have independently developed toll plaza models, which can only model an isolated …

Statistical Computation For Extreme Bridge Traffic Load Effects, Colin C. Caprani, E. J. O'Brien

Conference papers

The maintenance of highway infrastructure constitutes a major expenditure in many countries. This cost can be reduced significantly by minimizing the repair or replacement of highway bridges. In the assessment of existing bridges, the strength estimate tends to be more accurate than that of traffic loading, due to the more variable nature of loading. Recent advances in the statistical analysis of highway bridge traffic loading have resulted in more accurate forecasts of the actual loading to which a bridge is subject. While these advances require extensive numerical computation, they can significantly improve the accuracy of the calculation. This paper outlines …

Estimating Risk Of Failure Of Engineering Structures Using Predictive Likelihood, Colin C. Caprani, A. Bordallo-Ruiz, E. J. O'Brien

Conference papers

It has been common engineering practice to define characteristic values for loading and capacity of structures in order to assess the structural capacity of existing structures. This approach, yet practical and intuitive, lead to the comparison of deterministic values (characteristic values) that had to represent all the variability of the problem and is considered to be conservative, as usually loading is overestimated and capacity underestimated, yielding to calculations with high safety margins for the extreme events. Probabilistics methods have tried to overcom e this limitation by computing the overall probability of failure (Pf) for the lifetime of the structure, taking …

Study Of Same-Lane And Inter-Lane Gvw Correlation, Bernard Enright, Eugene J. O'Brien, Colin C. Caprani

Conference papers

The methodology used is to generate a number of years of simulated traffic and to use extreme value statistics to predict more accurately the characteristic loading for a given bridge. The parameters and probability distributions used in the Monte Carlo simulation must be based on observed sample traffic data. Some previous studies have made unsubstantiated assumptions regarding correlation between the Gross Vehicle Weights (GVW) of trucks in the same lane, or between trucks in adjacent, same-direction lanes. For this paper, an extensive database of Dutch Weigh-in-Motion data is analysed. Data are collected from two same-direction lanes and are time-stamped to …

Network Measures And Simulation For Knowledge Intensive Work Performance, Kon Shing Kenneth Chung, Liaquat Hossain, Joseph Davis

Faculty of Engineering and Information Sciences - Papers: Part A

We describe the process of designing a reliable and valid instrument for collecting network and attribute data. Here, we explore the relationship between social networks structure, information and communication technologies (ICT) use and attitude towards performance in knowledge intensive work. We first develop a model for exploring the inherent relationship between the three concepts based on existing literature. We then develop appropriate item sets for measuring different independent (network structure, ICT use) and dependent variables (performance). We use the reliable item sets along with justifications to construct different phases of our instrument. In doing so, we introduce a simulation approach …

Geant4 Simulation For Lhc Radiation Monitoring, M Glaser, S Guatelli, B Mascialino, M Moll, M G. Pia, F Ravotti

Faculty of Engineering and Information Sciences - Papers: Part A

Monitoring radiation background is a crucial task for the operation of LHC experiments. A project is in progress at CERN for the optimisation of the radiation monitors for LHC experiments. A simulation system based on Geant4, designed to assist the engineering optimisation of LHC radiation monitor detectors, is presented. Various detector packaging configurations are studied through their Geant4-based simulation, and their behaviour is compared.

Simulation Of Travelling Wave Dielectrophoresis Using A Meshless Method, Dafeng Chen, Hejun Du, Weihua Li, Chang Shu

Faculty of Engineering - Papers (Archive)

Manipulation and separation of micron-sized particles, particularly biological particles, using the dielectrophoretic effect is an emerging application in BioMEMS technology. This paper presents a numerical simulation for the four-phase traveling dielectrophoresis (DEP) using a novel meshless method - weighted least square finite difference (LSFD) scheme. The exact boundary condition and nonuniform point distribution were used in the calculation. Numerical results including the electrical potential, electrical field, traveling wave DEP forces and particle behavior are presented. Although the LSFD scheme was originally proposed in solving incompressible viscous flow, it is further demonstrated in this paper that the method is also well …

Cellular Neural Network Based Deformation Simulation With Haptic Force Feedback, Yongmin Zhong, Bijan Shirinzadeh, Gursel Alici, Julian Smith

Faculty of Engineering - Papers (Archive)

This paper presents a new methodology for deformable object modelling by drawing an analogy between cellular neural network (CNN) and elastic deformation. The potential energy stored in an elastic body as a result of a deformation caused by an external force is propagated among mass points by the non-linear CNN activity. An improved CNN model is developed for propagating the energy generated by the external force on the object surface in the natural manner of Poisson equation. The proposed methodology models non-linear materials with nonlinear CNN rather than geometric non-linearity in the most existing deformation methods. It can not only …

Requirements Gathering For Simulation, John Ryan, Cathal Heavey

Conference papers

This paper discusses the current shortfalls in support for the pre-coding phases of a discrete event simulation project. The paper then presents a process modelling technique, Simulation Activity Diagrams (SADs), developed to specifically support the initial requirements gathering phases of a simulation project. The paper concludes with an outline of proposed future developments to the modelling technique.

Geant4 Simulation In A Distributed Computing Environment, Susanna Guatelli, Alfonso Mantero, Patricia Mendez Lorenzo, Jakub Moscicki, Maria Grazia Pia

Faculty of Engineering and Information Sciences - Papers: Part A

A general system to perform a Geant4-based simulation in a distributed computing environment is presented. The architecture developed makes the system transparent to sequential or parallel execution and to the environment where the simulation is run: a single machine, a local cluster or a geographically distributed grid.

A Dynamic Heuristic For The Stochastic Unrelated Parallel Machine Scheduling Problem, Jean-Paul Arnaout, Ghaith Rabadi, Ji Hyon Mun

Engineering Management & Systems Engineering Faculty Publications

This paper addresses the problem of batch scheduling in an unrelated parallel machine environment with sequence dependent setup times and an objective of minimizing the total weighted mean completion time. The jobs' processing times and setup times are stochastic for better depiction of the real world. This is a NP-hard problem and in this paper, new heuristics are developed and compared to existing ones using simulation. The results and analysis obtained from the computational experiments proved the superiority of the proposed algorithm PMWP over the other algorithms presented.

A Hybrid Simulation Methodology To Evaluate Network Centricdecision Making Under Extreme Events, Sergio Quijada

Electronic Theses and Dissertations

Currently the network centric operation and network centric warfare have generated a new area of research focused on determining how hierarchical organizations composed by human beings and machines make decisions over collaborative environments. One of the most stressful scenarios for these kinds of organizations is the so-called extreme events. This dissertation provides a hybrid simulation methodology based on classical simulation paradigms combined with social network analysis for evaluating and improving the organizational structures and procedures, mainly the incident command systems and plans for facing those extreme events. According to this, we provide a methodology for generating hypotheses and afterwards testing …