Representation Of Layout Research Articles

More than meets the eye: The effect of planned fixations on scene representation

Scene memory frequently includes a swath of unseen layout beyond a photograph's boundaries (boundary extension [BE]; Intraub and Richardson, 1989). Might it be affected by the viewer's plan to shift fixation near a view boundary? When photographs were centrally fixated (500 msec), BE occurred following a 2-sec masked interval (Experiment 1). In Experiments 2-4, a cue during the first fixation signaled viewers to fixate an object near the left or right boundary. The picture was masked before the eyes landed. BE occurred on the cued side and on the top and bottom, but not on the uncued side. This relatively accurate performance on the uncued side suggests that inhibition of a movement to one side (in a competitive task) may also inhibit extrapolation of layout. BE on the to-be-fixated side, however, supports the idea that anticipatory representation of layout is an adaptive error that may aid the spatial integration of successive views.

Multilevel symmetry-constraint generation for retargeting large analog layouts

The strong impact of layout intricacies on analog-circuit performance poses great challenges to analog layout automation. Recently, template-based methods have been shown to be effective in reuse-centric layout automation for CMOS analog blocks such as operational amplifiers. The layout-retargeting method first creates a template by extracting a set of constraints from an existing layout representation. From this template, new layouts are then generated corresponding to new technology processes and new device specifications. For large analog layouts, however, this method results in an unmanageable template due to a tremendous increase in the number of constraints, especially those emerging from layout symmetries. In this paper, we present a new method of multilevel symmetry-constraint generation by utilizing the inherent circuit structure and hierarchy information from the extracted netlist. The method has been implemented in a layout-retargeting system called Intellectual Property Reuse-based Analog IC Layout (IPRAIL) and demonstrated 18 times reduction in the number of symmetry constraints required for retargeting an analog-to-digital converter layout. This enables our retargeting engine to successfully handle the complexities associated with large analog layouts. While manual relayout is known to take weeks, our layout-retargeting tool generates the target layout in hours and achieves comparable electrical performance

Representations of scene layout can consist of independent, functional pieces

A scene prime can induce a mental representation of layout that is functional in the sense that it facilitates the processing of depth relations in a subsequent same-scene target. Five experiments indicated that the representation can consist of separate and independent functional regions. In each experiment, primes with as many as four unrelated regions facilitated spatial processing within each region. The prime representations were functional despite structural discontinuity at region borders. The results indicate a limitation in the importance of structural constraint in representations of scene layout. However, when structural disruption occurred within regions that were perceived (Experiment 5), spatial processing was slowed. The results suggest that scene representation is more top down than is scene perception; the effects of structural disruption were overcome within representations, but not within perception.

Acalculia from a right hemisphere lesion: Dealing with “where” in multiplication procedures

The present study describes in detail, for the first time, a case of failure with multiplication procedures in a right hemisphere damaged patient (PN). A careful, step-by-step, error analysis made possible to show that an important portion of PN's errors could be better explained as spatial in nature and specifically related to the demands of a multi-digit multiplication. These errors can be distinguished from other types of errors, including those, expected after a right hemisphere lesion, determined by a generic inability to deal with spatial material, or from other deficits, like neglect, affecting cognitive capacities across the board. The best explanation for PN's problems is that he might have difficulties in relying on a visuo-spatial store containing a layout representation specific to multiplication. As a consequence, while knowing what, when and how to carry out the various steps, PN does not know where. What he may thus lack is a spatial schema of multiplication. Such schema is thought to help normal calculators in overcoming working memory demands of complex calculation by representing the information of where exactly each sub-step should be placed.

Figure and Ground in the Visual Cortex: V2 Combines Stereoscopic Cues with Gestalt Rules

Figure-ground organization is a process by which the visual system identifies some image regions as foreground and others as background, inferring 3D layout from 2D displays. A recent study reported that edge responses of neurons in area V2 are selective for side-of-figure, suggesting that figure-ground organization is encoded in the contour signals (border ownership coding). Here, we show that area V2 combines two strategies of computation, one that exploits binocular stereoscopic information for the definition of local depth order, and another that exploits the global configuration of contours (Gestalt factors). These are combined in single neurons so that the "near" side of the preferred 3D edge generally coincides with the preferred side-of-figure in 2D displays. Thus, area V2 represents the borders of 2D figures as edges of surfaces, as if the figures were objects in 3D space. Even in 3D displays, Gestalt factors influence the responses and can enhance or null the stereoscopic depth information.

The time course with which representations of scene layout become functional

The time course with which representations of scene layout become functional

An automated design system methodology and strategy for electrostatic discharge protection circuits in RF CMOS and BiCMOS silicon germanium technology

In a Cadence environment, a novel automated methodology is established to optimize (electrostatic discharge) ESD networks. An automated ESD design system for digital, analog and radio frequency (RF) circuits in a mixed signal semiconductor chips using a hierarchy of RF-characterized higher order graphical parameterized cells allows for co-synthesis of RF design and ESD evaluation. The auto-generated ESD design system includes CMOS and BiCMOS input, rail-to-rail and power clamp ESD network with layout, schematic and symbolic representations. Human body model (HBM), machine model (MM), and transmission line pulse (TLP) results demonstrate the operation of the ESD designs, and the region of optimum ESD results.

The effects of different viewing conditions on performance in simulated minimal access surgery

This study aimed to assess performance in simulated minimal access surgery (MAS) tasks under a range of viewing conditions. MAS conventionally uses 2d viewing systems which produce a flat image. However, 3d viewing systems which produce stereoscopic depth information should in principle lead to better depth perception, and improve performance on tasks which require appropriate spatial representation of layout and depth. The study compared a novel 3d viewing system with a state of the art 2d viewing system and a direct viewing condition (‘open surgery’) as a point of reference. Tasks included pulling and cutting of threads using standard surgical instruments. Medical students (n = 16) were allocated to viewing conditions according to a Latin square and carried out 120 tasks each. Assessment was by means of a 3d movement tracking device providing a number of performance parameters (time on task, velocity, number of movements, distance travelled). In addition instrument movement was video-recorded and analysed by four observers to validate the tracking device. Results from tracking data and observer data were highly correlated (r > 0.85). While open surgery naturally scored highest, the key finding was the clearly superior performance in the 3d condition compared to 2d. Thus modern 3d viewing systems can improve performance in a realistic task.

Ergonomic modelling and optimization of the keyboard arrangement with an ant colony algorithm

The arrangement of letters on a keyboard greatly influences the user's comfort and typing speed. With repetitive muscular injuries emerging and the amount of text to be treated increasing, the need for a better arrangement has come forth. To solve the problem, a non-trivial abstract representation of a physical keyboard layout and of type-writing rules is introduced. Having justified the choice of heuristic ergonomic criteria, a mathematical function for the ergonomic evaluation criteria is developed. Based on the ant colony optimization algorithm, an optimization algorithm is designed and applied to the problem described. The computational results representing the quality of the keyboard arrangements obtained for several languages are finally discussed and new solutions for optimization of the keyboard are presented.

Map-based navigation in mobile robots:: I. A review of localization strategies

For a robot, an animal, and even for man, to be able to use an internal representation of the spatial layout of its environment to position itself is a very complex task, which raises numerous issues of perception, categorization and motor control that must all be solved in an integrated manner to promote survival. This point is illustrated here, within the framework of a review of localization strategies in mobile robots. The allothetic and idiothetic sensors that may be used by these robots to build internal representations of their environment, and the maps in which these representations may be instantiated, are first described. Then map-based navigation systems are categorized according to a three-level hierarchy of localization strategies, which respectively call upon direct position inference, single-hypothesis tracking, and multiple-hypothesis tracking. The advantages and drawbacks of these strategies, notably with respect to the limitations of the sensors on which they rely, are discussed throughout the text.

TEG: a new post-layout optimization method

Post-layout is an important stage in the modern very large scale integration (VLSI) design. In this stage, the extraction and verification tools can get the most accurate results with the complete layout information, and the layout problems can be detected precisely for further design improvements or optimizations. But the problem is that the design optimization is very hard to perform in post-layout. Every design modification is under tight geometry constraints. Usually the designer either changes layout manually by layout editor, or goes back to previous placement or routing stage in order to have the preferred results. How to modify the layout becomes a bottleneck in the post-layout optimization. In this paper, we propose a new method to resolve this problem called the triangulation encoding graph (TEG) method. Based on an improved topological layout representation and a set of layout operation algorithms, TEG provides an incremental layout modification environment for post-layout optimizations. Experimental results show that TEG is efficient and effective in processing industry VLSI designs.

Representation and perception of scenic layout

This paper presents a cognitive approach to on-line spatial perception within scenes. A theoretical framework is developed, based on the idea that experience with a scene can activate a complex representation of layout that facilitates subsequent processing of spatial relations within the scene. The representations integrate significant, relevant scenic information and are substantial in amount or extent. The representations are active across short periods of time and across changes in the retinal position of the image. These claims were supported in a series of experiments in which pictures of scenes (primes) facilitated subsequent spatial relations processing within the scenes. The prime-induced representations integrated object identity and layout, were broad in scope, involved both foreground and background information, and were effective across changes in image position.

Implicit scene learning is viewpoint dependent.

When novel scenes are encoded, the representations of scene layout are generally viewpoint specific. Past studies of scene recognition have typically required subjects to explicitly study and encode novel scenes, but in everyday visual experience, it is possible that much scene learning occurs incidentally. Here, we examine whether implicitly encoded scene layouts are also viewpoint dependent. We used the contextual cuing paradigm, in which search for a target is facilitated by implicitly learned associations between target locations and novel spatial contexts (Chun & Jiang, 1998). This task was extended to naturalistic search arrays with apparent depth. To test viewpoint dependence, the viewpoint of the scenes was varied from training to testing. Contextual cuing and, hence, scene context learning decreased as the angular rotation from training viewpoint increased. This finding suggests that implicitly acquired representations of scene layout are viewpoint dependent.

Spatial layout representation for query-by-sketch content-based image retrieval

Most content-based image retrieval techniques and systems rely on global features, ignoring the spatial relationships in the image. Other approaches take into account spatial composition but usually focus on iconic or symbolic images. Nevertheless a large class of users' queries request images having regions, or objects, in well-determined spatial arrangements. Within the framework of query-by-sketch image retrieval, we propose a structured spatial layout representation. The approach provides a way to extract the image content starting from basic features and combining them in a higher-level description of spatial layout of components, characterizing the semantics of the scene. We also propose an algorithm that measures a weighted global similarity between a sketched query and a database image.

Internalized constraints in the representation of spatial layout

Shepard's (1994) choice of kinematic geometry to support his theory is questioned by Todorovic, Schwartz, and Hecht. His theoretical framework, however, can be applied to another domain that may be less susceptible to some of their concerns. The domain is the representation of spatial layout. [Hecht; Schwartz; Shepard; Todorovič]

On solving facility layout problems using genetic algorithms

Tam and Chan (1998) present a parallel genetic algorithm approach to solve the facility layout problem. They adopt a slicing tree representation of a floor layout. The coding scheme represents a layout as a string with three parts. This paper demonstrates the difficulties in applying classical crossover and mutation operators for solving facility layout problems. The paper modifies the representation of Tam and Chan and introduces a new preserving operation, referred to as transplanting , that manages to produce feasible offspring. It also studies the applicability of other genetic operations such as diagonal crossover and cloning in generating feasible offspring. The paper is written in a note format and the reader may refer to Tam and Chan for more details.

An iterative facility layout algorithm

In this paper we present a facility layout algorithm that iterates between a genetic algorithm with a slicing tree representation and a mixed-integer program with a subset of the binary variables set via the genetic algorithm. The genetic algorithm is very good at finding low-cost solutions while maintaining shape constraints on the departments. The slicing tree representation and the mixed-integer program are compatible in terms of layout representation, with the mixed-integer program representation more general. The mixed-integer program allows us to relax the last remaining constraints of the slicing tree representation of the genetic algorithm. We present our genetic algorithm and the iterative algorithm, while illustrating their performance on test problems from the literature. In 10 of the 12 problems, new lower best-cost solutions are found.

空間レイアウトの心的表象における方向依存性

空間レイアウトの心的表象における方向依存性

CARAMEL: Contamination And Reliability Analysis of MicroElectromechanical Layout

CARAMEL (Contamination And Reliability Analysis of MicroElectromechanical Layout) is a CAD tool for MEMS fault model generation. It is based on the integrated circuit contamination analysis tool CODEF and is capable of analyzing the impact of contamination particles on the behavior of microelectromechanical systems. CARAMEL's simulation output indicates that a wide range of defective structures are possible due to the presence of particulate contaminations. Moreover, electromechanical simulations of CARAMEL's mesh representations of defective layout has revealed that a wide variety of misbehaviors are associated with these defects. Several thousand contamination simulations were performed using CARAMEL on the surface micromachined comb-drive resonator. The results generated by CARAMEL identifies the comb drive as the most defect prone region of the microresonator and the deposition of the first structural layer as the most vulnerable processing step.

空間レイアウトの心的表象における方向依存性

空間レイアウトの心的表象における方向依存性