Hierarchical Topological Reasoning with Vague Regions

Abstract In graph-based function models, the function verbs and flow nouns are usually chosen from predefined vocabularies. The vocabulary class definitions, combined with function modeling grammars defined at various levels of formalism, enable function-based reasoning. However, the text written in plain English for the names of the functions and flows is presently not exploited for formal reasoning. This paper presents a formalism (representation and reasoning) to support semantic and physics-based reasoning on the information hidden in the plain-English flow terms, especially for automatically decomposing black box function models, and to generate multiple design alternatives. First, semantic reasoning infers the changes of flow types, flow attributes, and the direction of those changes between the input and output flows attached to the black box. Then, a representation of qualitative physics is used to determine the material and energy exchanges between the flows and the function features needed to achieve them. Finally, a topological reasoning is used to infer multiple options of composing those function features into topologies and to thus generate multiple alternative decompositions of the functional black box. The data representation formalizes flow phases, flow attributes, qualitative value scales for the attributes, and qualitative physics laws. An eight-step algorithm manipulates these data for reasoning. This paper shows four validation case studies to demonstrate the workings of this formalism.

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Separated Flow Topology in Compressors

Journal of Turbomachinery ◽

10.1115/1.4044132 ◽

2019 ◽

Vol 141 (9) ◽

Author(s):

James V. Taylor

Keyword(s):

High Speed ◽

Three Dimensional ◽

Separated Flow ◽

Cell Behavior ◽

Blade Design ◽

Flow Topology ◽

Design Point ◽

Topological Reasoning ◽

Blade Row ◽

Different Response

Abstract When a multistage high-speed compressor is operated away from its design point, extreme incidence is caused in some blade rows. This results in large, localized separations that are three dimensional in nature. In this paper, topological reasoning is used to describe the behavior of these three-dimensional separations. It is shown that two classes of separation exist: one in which the flow progresses from attached to separate in a smooth way and another where there is a discontinuity in the response of the flow topology. It is shown that the global structure of the flow depends on the type of topological response that occurs. When the response is discontinuous, nonaxisymmetric cells of separated blades are formed. When the response is smooth, the resultant separated flow is axisymmetric. The paper is split into two broad sections: The first section presents examples of the two different classes of topological response that can occur in a single blade row, and it also shows how an engineer can achieve a different response by altering the blade design. The second section covers the analysis of a multistage high-speed compressor. The compressor initially presents the discontinuous behavior with rotating cells of separations. It is then redesigned to reduce the severity of the cell behavior or remove it entirely.

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Geometria “imperfetta”: Luigi Vietti, villa La Roccia a Cannobio

ARCHALP ◽

10.30682/aa1903e ◽

2020 ◽

Author(s):

Veronica Dell’Aira

Keyword(s):

Previous Model ◽

Emotional Factors ◽

Domestic Activities ◽

Topological Reasoning ◽

The Alps ◽

Critical Interpretation ◽

Definition Of

"The article reviews the thought and work of Luigi Vietti (leading exponent of Italian Rationalism, then author of numerous domestic architectures, especially in Sardinia and on the Alps), through the presentation of one of his most important projects: the Villa La Roccia in Cannobio on the Lago Maggiore, completed in 1936. This project is based on a previous model, the “Villa su Roccia a Sperone”, designed with a promotional target in mind. The latter was published in 1932 on «Domus Magazine » and was exposed in several Rational Architecture events. Between 1930 and 1936 he develops a new concept of architecture in relation to the site by means of topological reasoning. This article uses critical interpretation to highlight that, in Vietti’s work, his interest in emerging architecture (shown by his participation in major founding events in the period between the Two World Wars) and the link to tradition, both contextual and disciplinary, manage to coexist in an often exemplary way. In Villa La Roccia, the character of the architecture as a whole and its details are remodeled to adapt to the rocky spur of Punta d’Amore. This makes the work better merge and blend with the surroundings. Even the interiors are recalibrated in relation to the site and domestic activities, emphasizing the precious definition of details and devoting particular attention to the perceptive-emotional factors of life within it."

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THE QUALITATIVE TREATMENT OF SPATIAL DATA

International Journal of Artificial Intelligence Tools ◽

10.1142/s0218213007003497 ◽

2007 ◽

Vol 16 (04) ◽

pp. 661-682 ◽

Cited By ~ 4

Author(s):

KAZUKO TAKAHASHI ◽

TAKAO SUMITOMO

Keyword(s):

Data Structure ◽

Spatial Data ◽

Spatial Reasoning ◽

Symbolic Representation ◽

Two Dimensional ◽

Efficient Treatment ◽

Dimensional Plane ◽

Topological Reasoning ◽

Qualitative Representation ◽

New Framework

This paper aims at an efficient treatment of spatial data using qualitative representation. We propose a new framework called PLCA, which provides a symbolic representation for the figure in a two-dimensional plane, focusing on the connections between regions. It is based on four simple objects: points(P), lines(L), circuits(C) and areas(A). The entire figure is represented as a combination of these objects. Pairs of areas, circuits or lines never cross. The simple, clear data structure based on objects makes the system feasible and easy to implement. A PLCA expression can be subject to topological reasoning such as judging the connection patterns of areas. We define the operations of area integration and area division on a PLCA expression. These operations preserve the consistency of the expression, and correspond to real actions on the figures. We can add attributes to each object, such as the properties that hold on an area or that an object represents, and make an attributed PLCA. The operations of area integration/division on an attributed PLCA correspond to the alteration of the classification level of objects, and semantic spatial reasoning can be performed on an attributed PLCA.

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