Intelligent Data Storage and Retrieval for Design Optimisation – an Overview

This paper documents the findings of a literature review conducted by the Sir Lawrence Wackett Centre for Aerospace Design Technology at RMIT University. The review investigates aspects of a proposed system for intelligent design optimisation. Such a system would be capable of efficiently storing (and compressing if required) a range of types of design data into an intelligent database. This database would be accessed by the system during subsequent design processes, allowing for search of relevant design data for re-use in later designs, allowing it to become very efficient in reducing the time for later designs as the database grows in size. Extensive research has been performed, in both theoretical aspects of the project, and practical examples of current similar systems. This research covers the areas of database systems, database queries, representation and compression of design data, geometric representation and heuristic methods for design applications.

Concurrency Control in Advanced Database Applications

Concurrency control has been thoroughly studied in the context of traditional database applications such as banking and airline reservations systems. There are relatively few studies, however, that address the concurrency control issues of advanced database applications such as CAD/CAM and software development environments. The concurrency control requirements in such applications are different from those in conventional database applications; in particular, there is a need to support non-serializable cooperation among users whose transactions are long-lived and interactive, and to integrate concurrency control mechanisms with version and configuration control. This paper outlines the characteristics of data and operations in some advanced database applications, discusses their concurrency control requirements, and surveys the mechanisms proposed to address these requirements

Concurrency Control in Advanced Database Applications

Concurrency control has been thoroughly studied in the context of traditional database applications such as banking and airline reservations systems. There are relatively few studies, however, that address the concurrency control issues of advanced database applications such as CAD/CAM and software development environments. The concurrency control requirements in such applications are different from those in conventional database applications; in particular, there is a need to support non-serializable cooperation among users whose transactions are long-lived and interactive, and to integrate concurrency control mechanisms with version and configuration control. This paper outlines the characteristics of data and operations in some advanced database applications, discusses their concurrency control requirements, and surveys the mechanisms proposed to address these requirements

Alternate Means of Digital Design Communication

This thesis reconceptualises communication in digital design as an integrated social and technical process. The friction in the communicative processes pertaining to digital design can be traced to the fact that current research and practice emphasise technical concerns at the expense of social aspects of design communication. With the advent of BIM (Building Information Modelling), a code model of communication (machine-to-machine) is inadequately applied to design communication. This imbalance is addressed in this thesis by using inferential models of communication to capture and frame the psychological and social aspects behind the communicative contracts between people. Three critical aspects of the communicative act have been analysed, namely (1) data representation, (2) data classification and (3) data transaction, with the help of a new digital design communication platform, Speckle, which was developed during this research project for this purpose. By virtue of an applied living laboratory context, Speckle facilitated both qualitative and quantitative comparisons against existing methodologies with data from real-world settings. Regarding data representation (1), this research finds that the communicative performance of a low-level composable object model is better than that of a complete and universal one as it enables a more dynamic process of ontological revision. This implies that current practice and research operates at an inappropriate level of abstraction. On data classification (2), this thesis shows that a curatorial object-based data sharing methodology, as opposed to the current file-based approaches, leads to increased relevancy and a reduction in noise (information without intent, or meaning). Finally, on data transaction (3), the analysis shows that an object-based data sharing methodology is technically better suited to enable communicative contracts between stakeholders. It allows for faster and more meaningful change-dependent transactions, as well as allow for the emergence of traceable communicative networks outside of the predefined exchanges of current practices

Data-structure builder for VLSI/CAD software

Relational database systems have successfully solved many business data processing problems. The primary reason of this success is that the relational data model provides a simple, yet flexible view of data as tables. In studying VLSI/CAD data, we noticed that they are often represented in formats similar to relational tuples. Therefore, they can be stored easily in relational tables. However, it is generally agreed that conventional relational database systems are inefficient for VLSI/CAD applications, since such applications often access large amounts of data repetitively. In order to solve this problem, we designed and implemented a data mapping subsystem that converts VLSI/CAD data stored in relational tables into internal data structures so that they can be efficiently manipulated in C. By using our data mapping language, we could reduce the amount of code required by the data-structure construction parts of some real VLSI/ CAD tools to about 1/10 of that required by C implementation. Our data-structure builder consumes several times more CPU cycles

Concurrency Control in Rule-Based Software Development Environments

This dissertation investigates the concurrency control problem in software development environments (SDEs). The problem arises when multiple developers perform activities that concurrently access the project's components, stored as database objects. The interleaved execution of the developers' activities leads to interference if they access overlapping sets of objects concurrently. An SDE can ensure that activities never interfere by modeling their execution in terms of atomic transactions and allowing only serializable schedules. This prevents cooperation, which requires some degree of interference between the activities of multiple developers. To allow cooperation, an SDE must be provided with semantic information about development activities. In rule-based SDEs, the necessary information is readily available in the set of rules that defines the process model of a project. The rules are loaded into the SDE, which provides process-specific assistance through a rule chaining engine. A single user command might lead the chaining engine to initiate a rule chain. The concurrency control problem in rule-based SDEs manifests itself in terms of interference between concurrent rule chains. We present a mechanism that extracts semantic information from the process model to solve the concurrency control problem without obstructing cooperation. The mechanism is composed of two modules: (1) a conflict detection module, which models activities as nested transactions and uses two-phase locking to detect interference; and (2) a conflict resolution module, which employs two protocols to resolve interference. The first protocol, seep, uses the process model to implement a priority-based scheme that aborts the "least important" of the interfering transactions. The second protocol, peep, overrides SCCP by consulting process-specific control rules, written by the project administration. Each control rule describes a specific interference and the actions that resolve it. We have implemented SCCP and parts ofPCCP in MARVEL, a multi-user rule-based SDE developed at Columbia

Virtual files: a Framework for Experimental Design

The increasing power and decreasing cost of computers has resulted in them being applied in an ever widening area. In the world of Computer Aided Design it is now practicable to involve the machine in the earlier stages where a design is still speculative, as well as in the later stages where the computer's calculating ability becomes paramount. Research on database systems has not followed this trend, concentrating instead on commercial applications, with the result that there are very few systems targeted at the early stages of the design process. In this thesis we consider the design and implementation of the file manager for such a system, first of all from the point of view of a single designer working on an entire design, and then from the point of view of a team of designers, each working on a separate aspect of a design. We consider the functionality required of the type of system we are proposing, defining the terminology of experiments to describe it. Having ascertained our requirements we survey current database technology in order to determine to what extent it meets our requirements. We consider traditional concurrency control methods and conclude that they are incompatible with our requirements. We consider current data models and conclude that, with the exception of the persistent programming model, they are not appropriate in the context required, while the implementation of the persistent programming model provides transactions on data structures but not experiments. The implementation of experiments is considered. We examine a number of potential methods, deciding on differential files as the one most likely both to meet our requirements and to have the lowest overheads. Measurements conducted on both a preliminary and a full-scale implementation confirm that this is the case. There are, nevertheless, further gains in convenience and performance to be obtained by exploiting the capabilities of the hardware to the full; we discuss these in relation to virtual memory systems, with particular reference to the VAX/VMS environment. Turning to the case where several designers are each working on a (nearly) distinct part of a design, we consider how to detect conflicts between experiments. Basing our approach on optimistic concurrency control methods, we show how read and write sets may be used to determine those areas of the database where conflicts might arise. As an aside, we show how the methods we propose can be used in an alternative approach to optimistic concurrency control, giving a reduction in system overheads for certain applications. We consider implementation techniques, concluding that a differential files approach has significant advantages in maintaining write sets, while a two-level bitmap may be used to maintain read sets efficiently

Ein Molekül-Atom-Datenmodell für Non-Standard-Anwendungen : Anwendungsanalyse, Datenmodellentwurf und Implementierungskonzepte

Ziel der vorliegenden Arbeit ist die Erarbeitung und Nutzbarmachung von Datenbankkonzepten für sog. Non-Standard-Anwendungen. Darunter versteht man im OB-Bereich Anwendungen aus den Gebieten CAD/CAM, VLSI-Entwurf, Software-Entwicklung, Büroautomatisierung, Expertensysteme etc. Die zentralen Fragestellungen, zu denen es Antworten zu finden gilt, sind: - Welche Anforderungen werden von den Non-Standard-Anwendungen an die Datenhaltung gestellt? - Wie sehen dazu passende Architekturen und Datenmodelle für NDBS (das sind DBS für Non-Standard-Anwendungen) aus? - Nach welchen Konzepten sind solche NDBS zu entwerten und zu implementieren? Dazu werden verschiedene OB-basierte Prototypen analysiert und vergleichend einander gegenübergestellt. Im einzelnen wurden basierend auf konventionellen Datenbanksystemen verschiedenen Typs (Netzwerk- und Relationenmodell) Anwendungssysteme aus unterschiedlichen ingenieurwissenschaftlichen Bereichen (3D-Modellierung, Verwaltung geographischer Daten und VLSI-Entwurfswerkzeug) sowie aus dem Expertensystembereich (Diagnosesystem) entwickelt; ihr Leistungsverhalten wurde unter einer praxisnahen Last aufgezeichnet und detailliert untersucht. Ausgehend von diesen Analyse- und Vergleichsergebnissen wird ein Anforderungskatalog erstellt, der konkrete Aussagen über die Datenstrukturen der Anwendungsobjekte und die zugehörigen Verarbeitungscharakteristika zusammenfaßt

EUBIM 2020. Congreso internacional BIM/ 9º encuentro de usuarios BIM

Building Information Modeling (BIM) es el proceso de generación y gestión de datos del edificio durante su ciclo de vida, utilizando software dinámico de modelado de edificios en 3D y en tiempo real,para disminuir la pérdida de tiempo y recursos en el diseño y la construcción.Este proceso produce el modelo de información del edificio (también llamado modelo BIM),que abarca la geometría del edificio,las relaciones espaciales, la información geográfica, así com las cantidades y las propiedades de los componentesOliver Faubel, I.; Fuentes Giner, MB. (2020). EUBIM 2020. Congreso internacional BIM/ 9º encuentro de usuarios BIM. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/146831EDITORIA