Construction time-cost model in Croatia

The paper deals with the applicability of the time-cost model for calculating the sustainable construction time for building projects in Croatia. In this model the time is expressed as a function of money in the project, while the specific constants K and B need to be determined. These constants depend on economic characteristics of the country or a larger area, therefore had to be separately calculated for a region with similar economic characteristics. The modelling of the constants was performed for two groups of building projects - the roads and residential and office multi-storey buildings. The obtained results have been analyzed and compared to the corresponding results from abroad

A critical evaluation and comparison of four manufacturing simulators using analytic hierarchy process

In the period of continuous change in global business environment, organizations, large and small, are finding it increasingly difficult to deal with, and adjust to the demands for such change. Simulation is a powerful tool for allowing designers imagine new systems and for enabling them to both quantify and to observe behaviour. Currently the market offers a variety of simulation software packages. Some are less expensive than others. Some are generic and can be used in a wide variety of application areas while others are more specific. Some have powerful features for modelling while others provide only basic features. Modelling approaches and strategies are different for different packages. Companies are seeking advice about the desirable features of software to manufacture simulation, depending on the purpose of its use. Because of this, the importance of an adequate approach to simulation software evaluation and comparison is apparent. This paper presents a critical evaluation of four widely used manufacturing simulators: NX-IDEAS, Star-CD, Micro Saint Sharp and ProModel. Following a review of research into simulation software evaluation, an evaluation and comparison of the above simulators is performed. This paper illustrates and assesses the role the Analytic Hierarchy Process (AHP) played in simulation software evaluation and selection. The main purpose of this evaluation and comparison is to discover the suitability of certain types of simulators for particular purposes

Forecasting the impact of virtual environment technology on maintenance training

To assist NASA and the Air Force in determining how and when to invest in virtual environment (VE) technology for maintenance training, we identified possible roles for VE technology in such training, assessed its cost-effectiveness relative to existing technologies, and formulated recommendations for a research agenda that would address instructional and system development issues involved in fielding a VE training system. In the first phase of the study, we surveyed VE developers to forecast capabilities, maturity, and estimated costs for VE component technologies. We then identified maintenance tasks and their training costs through interviews with maintenance technicians, instructors, and training developers. Ten candidate tasks were selected from two classes of maintenance tasks (seven aircraft maintenance and three space maintenance) using five criteria developed to identify types of tasks most likely to benefit from VE training. Three tasks were used as specific cases for cost-benefit analysis. In formulating research recommendations, we considered three aspects of feasibility: technological considerations, cost-effectiveness, and anticipated R&D efforts. In this paper, we describe the major findings in each of these areas and suggest research efforts that we believe will help achieve the goal of a cost-effective VE maintenance training system by the next decade

SIMULATION & VALIDATION OF BODY FRAMING ASSEMBLY LINE USING WITNESS

Computational simulation model has been a very useful tools for most organization it‟s provide a cost effective, quantitative means for planning, designing, and analyzing system proposals. The problem is most manufacturing plant simulation model is unavailable. The objective of this project is to develop a simulation model of an assembly plant and validate the model. The simulation model is developed using Witness12 Simulation software and adopt project execution approach from numbers of previous technical paper. Result from this project, there is a big difference on the production output on the simulation model and the actual plant. This is due to less information sharing between institution and industry

Interactive Virtual Training: Implementation for Early Career Teachers to Practice Classroom Behavior Management

Teachers that are equipped with the skills to manage and prevent disruptive behaviors increase the potential for their students to achieve academically and socially. Student success increases when prevention strategies and effective classroom behavior management (CBM) are implemented in the classroom. However, teachers with less than 5 years of experience, early career teachers (ECTs), are ill equipped to handle disruptive students. ECTs describe disruptive behaviors as a major factor for stress given their limited training in CBM. As a result, disruptive behaviors are reported by ECTs as one of the main reasons for leaving the field. Virtual training environments (VTEs) combined with advances in virtual social agents can support the training of CBM. Although VTEs for teachers already exist, requirements to guide future research and development of similar training systems have not been defined. We propose a set of six requirements for VTEs for teachers. Our requirements were established from a survey of the literature and from iterative lifecycle activities to build our own VTE for teachers. We present different evaluations of our VTE using methodologies and metrics we developed to assess whether all requirements were met. Our VTE simulates interactions with virtual animated students based on real classroom situations to help ECTs practice their CBM. We enhanced our classroom simulator to further explore two aspects of our requirements: interaction devices and emotional virtual agents. Interactions devices were explored by comparing the effect of immersive technologies on users\u27 experience (UX) such as presence, co-presence, engagement and believability. We adapted our VTE originally built for desktop computer, to be compatible with two immersive VR platforms. Results show that our VTE generates high levels of UX across all VR platforms. Furthermore, we enhanced our virtual students to display emotions using facial expressions as current studies do not address whether emotional virtual agents provide the same level of UX across different VR platforms. We assessed the effects of VR platforms and display of emotions on UX. Our analysis shows that facial expressions have greater impact when using a desktop computer. We propose future work on immersive VTEs using emotional virtual agents

Distributed Simulation in Manufacturing Using High Level Architecture

Manufacturing is a critical industry for all major economies. Every individual and industry depends on manufactured goods, which makes manufacturing crucial to the national economies. Competition is increasingly hard and globalization is leading to worldwide distribution of production, products and services, affecting all countries and economical regions. At the same time, markets are changing. Customers call for faster product changes and demand products, which are increasingly targeted to individual needs. Mass production is therefore replaced by customised and personalised production of individual products. Distributed simulation has the potential to become widely applicable for geographically-dispersed manufacturing environments, as is the case with desktop manufacturing or rapidly deployable micro-assembly stations. This thesis focuses on creating a generic framework that permits the distribution of manufacturing simulations, which was one of the goals of the MS2Value (Modeling and Simulation of Manufacturing Systems for Value Chains) project. Companies, nowadays, normally have their activities and resources geographically dispersed, which represents a challenge for the reusability and interconnection of their manufacturing simulation models. Different approaches have been taken by different communities like the research and military community, but no solution has been presented yet in the manufacturing field. The thesis work presented here proposes the use of the HLA (High Level Architecture) in combination with a simulation software as a solution to these problems. This proposal is demonstrated by an implementation of a distributed simulation using 3DCreate and an open source RTI (Runtime Infrastructure). /Kir1

Development of a standard framework for manufacturing simulators

Discrete event simulation is now a well established modelling and experimental technique for the analysis of manufacturing systems. Since it was first employed as a technique, much of the research and commercial developments in the field have been concerned with improving the considerable task of model specification in order to improve productivity and reduce the level of modelling and programming expertise required. The main areas of research have been the development of modelling structures to bring modularity in program development, incorporating such structures in simulation software systems which would alleviate some of the programming burden, and the use of automatic programming systems to develop interfaces that would raise the model specification to a higher level of abstraction. A more recent development in the field has been the advent of a new generation of software, often referred to as manufacturing simulators, which have incorporated extensive manufacturing system domain knowledge in the model specification interface. Many manufacturing simulators are now commercially available, but their development has not been based on any common standard. This is evident in the differences that exist between their interfaces, internal data representation methods and modelling capabilities. The lack of a standard makes it impossible to reuse any part of a model when a user finds it necessary to move from one simulator to another. In such cases, not only a new modelling language has to be learnt but also the complete model has to be developed again requiring considerable time and effort. The motivation for the research was the need for the development of a standard that is necessary to improve reusability of models and is the first step towards interchangability of such models. A standard framework for manufacturing simulators has been developed. It consists of a data model that is independent of any simulator, and a translation module for converting model specification data into the internal data representation of manufacturing simulators; the translators are application specific, but the methodology is common and illustrated for three popular simulators. The data model provides for a minimum common model data specification which is based on an extensive analysis of existing simulators. It uses dialogues for interface and the frame knowledge representation method for modular storage of data. The translation methodology uses production rules for data mapping

An Analysis of WPI\u27s Power Grid

This project developed an alterable interactive simulation of the present WPI campus power grid. The simulation accurately represents the voltage, switch gear, breaker ratings, transformer locations, connectivity, and impedance of the actual campus electrical network. This electrical information is overlaid on a three-dimensional Geographical Information System (GIS) model of the campus showing building locations. Simulation results were verified against actual system data. This model will facilitate system studies of campus grid upgrades

Simulator Networking Handbook: Distributed Interactive Simulation Testbed

Report is an attempt to collect and organize a large body of knowledge regarding the design and development of simulation networks, particularly distributed interactive simulation