Frame-based Approach Research Articles

Scan conversion between 1050 2:1 60 Hz and 525 1:1 30 Hz U and V color components

In an MPEG (Motion Pictures Experts Group) video coding system, a color component downsampling from 1050 2:1 60 Hz to 525 1:1 30 Hz line scan formats must be carried out on the U and V color component source signals. One scheme presently used to accomplish the required U and V downsampling, called frame-based color subsampling, is thoroughly analyzed. In addition, field-based color downsampling is analyzed and compared with the frame-based color downsampling. The maximum vertical and temporal resolution of the original U, V signals is 1050 tvl and 30 Hz. An analysis in the vertical-temporal Fourier-transform domain shows that the best possible vertical and temporal resolution of the frame-based approach is 525 tvl and 15 Hz. For the field-based approach the maximum possible vertical and temporal resolution is 265.5 tvl and 30 Hz. The fact that the temporal resolution is reduced by one half in the frame-based approach leads to blurring of horizontal edges on moving objects, although in quasi-stationary picture sequences this approach performs well in the sense that vertical aliasing artifacts can be reduced by the use of a proper vertical filter.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Integrated knowledge-based machining system for rotational parts

The research work describes an attempt to model the knowledge of an experienced process planner and NC programmer by engaging expert system techniques. An experimental system has been developed in order to satisfy the need for an integrated automated system in a machining-based manufacturing environment. The system adopts a frame-based approach for the generation of machining tasks for turned parts.

Modelling the emergence of design descriptions across schemata

An exploration of how connectionist systems can be used to model Important aspects of design reasoning is presented: the way design appears to involve memory; and a ‘holistic’ kind of reasoning by which designs appear to emerge from that memory. A simple connectionist system is used to demonstrate how information about schemata (in this case, subfloor construction types) is stored implicitly after the system is exposed to a number of specific examples. New schemata can emerge from this information. The paper includes a discussion of design, a comparison between a connectionist and a frame-based approach to representing design knowledge, a technical explanation of a connectionist system, and the demonstration of an implemented example.

A frame-based approach for the making of holes in turned parts and its further development

The use of computer-aided process planning systems is aimed at securing the integration of production, at increasing productivity and at reducing manufacturing costs. Though there has been much effort in this field and the objectives are the same as those of many other related systems, the differences in the present work lie in the approach and concepts employed. The work focusses on operation planning, a sub-domain of process planning, for NC/CNC lathes, the role of which is to convert the design data into manufacturing instructions. The decision-making processes involve mainly the determination of the operations, the sequence of the operations, the selection of the tools, the selection of the cutting parameters and the auxiliary functions. The development of the planning system using a frame-based expert-system building tool is discussed.

Knowledge based system support for introductory power system network analysis on personal computers

The application of artificial intelligence for knowledge-based systems (KBSs) is reviewed and applied to the basic power system network analysis problem. A frame-based KBS has been developed to assist students in preparing data for power flow analysis. The prototype for a power flow knowledge-based system (PFKBS) is an example of a shallow knowledge system. The details of an implementation for a simple power system are used to highlight the difference between a frame-based approach and a conventional FORTRAN approach. The data structures used within the developed frame-based KBS are presented in sufficient detail for anyone to regenerate the database. The user interface is illustrated for a small power system. The method of preparing data for the power flow as a sequence of knowledge bases is discussed for the example system. >

An expert system approach to parameterized module synthesis

An expert system that converts a description of transistor connectivity into a parameterized CMOS modules is presented. PAMS (parameterized module synthesis) was designed to augmented a standard cell environment by automatically generating special-purpose modules parameterized in terms of area, speed, and power dissipation. A frame-based approach facilitates the representation of specific parameterization-domain knowledge. Allowing parameterization differentiates PAMS from previous expert systems in this field. >

Frame-Based Software Engineering

One of reusability's main problems is how to easily modify available components. This frame-based approach handles the problem.

Knowledge representation and planning control in an expert system for the creative design of mechanisms

An interactive system, referred to as MECXPERT {Mechanism Expert}, has been designed with the expressed purpose of assisting nonexpert design engineers in creating mechanisms for fulfilling specific motion-conversion and/or power-transmission requirements. The particular knowledge representation scheme chosen for this application comprises a hybrid formulation of a rule-based production system with a frame-based approach. The underlying control strategy is based on a series of special-purpose, domain-specific operators whose function is to move from one problem space to another through various stages or ‘states’ that comprise the mechanism design process.The primary focus of this paper centers on the representation of knowledge and its control within an expert system for creative mechanism design. An overview summarizing the reasons for developing such an expert system is provided, and the formulation of a problem is discussed through an example taken from the design of a variable-stroke internal-combustion engine mechanism.