Sergio Scheer

An object model for collaborative CAD environments

This paper presents a distributed dynamic object model that is aligned with the concept of design history in the context of design problem solving activities. A distributed object model is proposed as an enabling feature for distributed CAD (computer-aided design) allowing teams to work cooperatively, accessing and exchanging information at run time in a distributed engineering environment. The architecture of the proposed CAD environment allows for the artefact properties to be associated with any relevant aspect of the design process, including those related with the artefact specification, but also with the organisation hierarchy, planning and process workflow.

Distributed object model for collaborative CAD environments based on design history

This paper presents new concepts for distributed dynamic design environments that deal with three aspects not effectively considered by the design literature in an integrated way: design history, CAD data model, and virtual prototyping. The present work details a design history model that gives support to views of higher levels than those usually found in design journals of CAD systems. The dynamic nature of the distributed environment is provided by an innovative mechanism that is not dependent on CORBAs DII or any other specialized middleware structure. Moreover, this paper presents an effective integration of a geometry bus on the top of a communication layer with strong support to mutant distributed objects at run time.

Distributed Agents Supporting Event-Driven Design Processes

In event-driven design processes, a digital mock-up is made of entities which are more than 3D, passive, virtual objects; they may be seen as part of a society of agents whose behavior emerges from their mutual interaction. This paper proposes the concept of Extended Constraint Graphs with bi-directional reactivity and one-way actions to represent reactivity and pro-activeness in a society of distributed design agents. Also, while the majority of CORBA applications in CAD systems uses static invocations, this paper presents an original approach to deal with the necessarily dynamic nature of event-driven design processes through the use of the interpreted language Lua with a CORBA binding called LuaOrb. Moreover, the use of ACIS as a Geometry Bus is presented in the context of the CORBA dynamic invocation interface.

Reactive Design Agents in Solid Modelling

This paper proposes a reactive agent architecture for the integration of solid modelling processes into more general design processes. The basic idea is to focus on reactivity rather than on symbolic representations of design knowledge. Also an Application Programming Interface is proposed to help developers writing intelligent CAD systems with links to any open architecture geometric modeller. In the proposed approach, solid modelling processes are formally immersed in the design process with the concept of modified CSG trees. Furthermore, solids are considered to be reactive design agents. A working system is also presented.

CAD and CAE integration through scientific visualization techniques for illumination design

Engineers tend to use different software to perform tasks such as geometry modeling, database management, numerical analysis, and visualization. This may cause decrease of productivity and loss of information during the conversion process between different data file formats. This paper presents a computer aided design (CAD) and computer aided engineering (CAE) system integration using scientific visualization tools and techniques. It deals with the development of a 3D CAD add-in for lighting analysis which uses the CAD model as 3D interface for creating a lighting scheme, processing, and visualizing 2D or 3D illuminance fields. Visualization features as color and contour mapping were developed using the visualization toolkit (VTK) toolkit. The application integrates all functionalities of the 3D CAD with tools for light sources database management, pre-processing, processing, and post-processing of illuminance fields in a single environment. This approach increases productivity and eliminates the need for different software.

Online algorithms supporting emergence in distributed CAD systems

Abstract The rule-based approach from traditional AI and the conventional constraint satisfaction algorithms are not adequate to cope with the unpredictable events and interactive computations in distributed CAD environments. This paper claims that the problems faced by distributed CAD systems require solutions based on the concepts of emergence, reactivity, and online algorithms. The present paper presents Extended Constraints Graphs (ECGs) as online algorithms supporting emergence in a network of reactive agents. ECGs represent an effective solution for the nonlinear constraint problem in cyclic graphs, which are distributed over a heterogeneous computer network. The relationships between agents in an ECG are generic, distributed, recursive and nonlinear — a problem not solved in the literature. Also this paper presents a CORBA model integrated with a Geometry Bus to support distributed virtual prototype whose variables can be defined in terms of ECGs.

On-Site BIM Model Use to Integrate 4D/5D Activities and Construction Works: A Case Study on a Brazilian Low Income Housing Enterprise

This paper presents a practical application of integrating an integrated model (BIM) with scheduling and cost planning. It also describes the steps undertaken to plan and re-plan a project, at each new decision taken by the multidisciplinary team. The study was conducted during the development of a low income housing enterprise nearby the city of Curitiba in Brazil. The undertaken application demonstrates how to extract information from the BIM model for uses to production planning and control on site construction. Throughout the work breakdown structure and the unit costs for bill of materials, the model can be integrated with planning and helps the execution phase as well. With 4D/5D simulation, the information and decision of design phase was taken to the construction site. The results show some decisions and uses of the integrated model on the design phase and production planning and control on construction site. Some difficulties experienced by the development team are also reported. The main conclusions of this study confirm the advantages and disadvantages of using 4D/5D BIM modeling found in the literature, such as supporting lean construction principles on production.

Controle de qualidade e visualização de dados de radares meteorológicos

Analises e estudos meteorologicos permitem realizar previsoes sobre o clima e antever eventos severos como enchentes, tempestades e tornados. Muitas dessas analises baseiam-se em dados gerados por modelos numericos ou obtido por sensores em satelites e radares meteorologicos, alem de pluviometros, distometros e outros. Radares meteorologicos tem a caracteristica de possibilitar a previsao de eventos severos a curto prazo, ou seja, por meio dos dados obtidos por esses equipamentos e possivel identificar e monitorar tempestades severas, ocorrencia de granizo. Nesse contexto, sistemas de processamento e visualizacao interativa sao de grande importancia pois auxiliam a analise e consequente tomada de decisao com base na observacao desses dados. No entanto, considerando o desenvolvimento da tecnologia de radares ocorrida nos ultimos anos, processar e visualizar grandes quantidades de dados tem se tornado um desafio. Radares de dupla polarizacao, por exemplo, geram cerca e dez vezes mais informacoes que radares de polarizacao simples, mas tambem geram mais ruidos e informacoes que precisam ser filtradas. Este trabalho relata o desenvolvimento de um sistema interativo para processamento e visualizacao de dados de radares meteorologico, bem como a implementacao de um algoritmo para o controle da qualidade dos dados. O algoritmo desenvolvido consiste em adaptacoes realizadas a partir de algoritmos encontrados na literatura, mas com uma preocupacao maior em relacao ao desempenho. A ideia tem sido buscar um equilibrio entre o tempo de processamento e a acuracia do resultado para que o filtro desenvolvido possa ser integrado a um sistema de visualizacao interativo. Os resultados obtidos sao apresentados e discutidos.

The Adaptation and Application of an ICT-Supported Collaboration Model: A Case Study in a Public Sector Construction Project Department

A construction project in the public sector has additional complexity due to the number of disciplines and stakeholders with individual interests and different ways of expressing and interpreting information. The approach of collaboration helps to define common goals and commitment between the parties, and the Information and Communication Technology (ICT) acts as the support structure for relationships due to its characteristics to support communication, graphical representations and project development. This paper aims to apply a collaboration model supported by ICT in a building and infrastructure design process related to the public sector, listing the reasons why the parties collaborate and cooperate, the necessary structure and the ICT aspects that can provide support. The research method is exploratory in a case study fashion which consisted of a theoretical research to define the initial collaboration model framework adaptation and the field study to validate it. The case study was developed in a City Hall in the South of Brazil. The results present opportunities for reflection about the collaborative management of public projects and confirm that organizational and behavioral aspects are relevant to better understand the improvements generated by ICT use by public building design teams.