Layout Complexity Research Articles

Design guidelines for the choice between single and dual pressure layouts in organic Rankine cycle (ORC) systems

The efficiency benefits deriving from the staging of the evaporation process into multiple pressure levels are well known in the field of gas-steam natural gas combined cycles where dual and triple pressure bottoming cycles represent the standard layouts. A similar development of the cycle architecture has not been observed in the field of organic Rankine cycle systems (ORCs). In this paper the dual pressure layout is compared against the single pressure one at subcritical conditions in the utilization of a geothermal heat source in the range 100–200 °C, and considering a set of working fluids wide enough to take advantage of the features of both layouts. The paper proposes simple and unambiguous design guidelines to avoid the unnecessary complexity of the dual pressure layout when the single pressure one already ensures the highest power output, while taking advantage of its full potential in all the other conditions. Results show that the power output gains deriving from the dual pressure configuration are particularly high (up to 29%) at lower geothermal fluid temperatures (100–125 °C) and gradually diminish at higher temperatures (150–200 °C) where some of the selected fluids already obtain the best thermal matching with the heat source in the single pressure configuration.

The Structure-Immittance Approach for Passive Vibration Control

This paper proposes a new method, the structure-immittance approach, for designing the passive vibration absorbers consisting of inerters, dampers and springs. When considering possible configurations for these elements broadly, one of two exist approaches may be taken, either a structure-based or an immittance-based approach. Both methods have their advantages and disadvantages. In this paper, the new approach combines the advantages of the existing ones. It can both consider a full set of absorber layouts together (the advantage of immittance-based approach), and restrict the complexity, topology and element values of the candidate layouts (the advantage of structure-based approach). The structural immittances covering a full set of possible networks with one damper, one inerter and at most one spring are derived and applied to a civil engineering study. This demonstrates the advantages of the new methodology in being able to identify the optimum configurations for different element constraints.

Parallel Self-Assembly of Polyominoes under Uniform Control Inputs

We present fundamental progress on parallel self-assembly using large swarms of microscale particles in complex environments, controlled not by individual navigation, but by a uniform, global, external force with the same effect on each particle. Consider a 2-D grid world, in which all obstacles and particles are unit squares, and for each actuation, particles move maximally until they collide with an obstacle or another particle. We present algorithms that, given an arbitrary 2-D structure, design an obstacle layout. When actuated, this layout generates copies of the input 2-D structure. We analyze the movement and spatial complexity of the factory layouts. We present hardware results on both a macroscale, gravity-based system, and a microscale, magnetically actuated system.

Environmental layout complexity affects neural activity during navigation in humans.

Navigating large-scale surroundings is a fundamental ability. In humans, it is commonly assumed that navigational performance is affected by individual differences, such as age, sex, and cognitive strategies adopted for orientation. We recently showed that the layout of the environment itself also influences how well people are able to find their way within it, yet it remains unclear whether differences in environmental complexity are associated with changes in brain activity during navigation. We used functional magnetic resonance imaging to investigate how the brain responds to a change in environmental complexity by asking participants to perform a navigation task in two large-scale virtual environments that differed solely in interconnection density, a measure of complexity defined as the average number of directional choices at decision points. The results showed that navigation in the simpler, less interconnected environment was faster and more accurate relative to the complex environment, and such performance was associated with increased activity in a number of brain areas (i.e. precuneus, retrosplenial cortex, and hippocampus) known to be involved in mental imagery, navigation, and memory. These findings provide novel evidence that environmental complexity not only affects navigational behaviour, but also modulates activity in brain regions that are important for successful orientation and navigation.

Influence of print advertising layout complexity on visual attention

In the contemporary overcrowded market there is a high competition for capturing consumers’ attention. Few decades ago attracting consumers’ visual attention was easier; however, modern consumers become advertising-resistant. Moreover, people even tend to ignore ads before seeing them. Such advertising resistance leads to a situation when the creativity becomes important. As creativity in advertising has many aspects, we considered the advertising complexity as one of them. The aim of the research is to determine the influence of the complexity of print advertising on visual attention. Three objectives are set to reach the aim: (1) to determine the theoretical criteria of advertising complexity; (2) to select sample advertisements meeting each selected criterion; (3) to provide the eye-tracking experiment with the chosen advertisements. The research reveals that advertising complexity has a positive influence on consumers’ visual attention to the advertisement, but negative influence on consumers’ visual attention to the brand presented in the advertisement. The research enables the eye-tracking-based determination of the best suitable level of advertising complexity to attract visual attention. The analysis of experiment participants’ number of eye fixations and mean viewing time enables the determination of guidelines for advertising creation.

Visual-orthographic complexity of Akshara and eye movements in reading: A study in Kannada alphasyllabary

Eye movement patterns in reading vary across languages depending upon the grain size and transparency of the orthography. We studied eye movements in reading Kannada akshara, an alphasyllabary used in South India. Kannada is a very transparent orthography in which the complexity of script layout of orthographic syllables, called akshara, increases when vowel ligatures or more consonants are incorporated into them. There are three levels of such akshara complexity in Kannada: akshara representing vowel alone or a consonant with inherent shwa (basic letters), akshara representing consonant and vowel ligature combination, and akshara representing conjunct consonants and vowel combination. We recorded eye movement patterns from 51 children—17 typically developing (TD), 17 with reading disability (RD) and 17 reading-level-matched typically developing readers (RL) when reading sentences made of different types of akshara. The results showed that the visual-orthographic complexity of akshara in conjunct consonan...

Design Optimization of Integrated Magnetic Core Inductors

This paper presents a design study of novel geometrical configurations for miniaturized toroidal planar core thin-film inductors. A standard core with square-shaped toroidal geometry is compared with a new core with serpentine toroidal geometry. A design procedure is provided to maximize the inductance value of a square toroid in a certain footprint area. In addition, the mathematical model of the inductor demonstrates the possibility to further increase the maximum inductance value for closed or air-gap core inductors in a given footprint area (up to 35% in 16 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ), by means of a more efficient use of the core surface area in the case of serpentine geometry, assuming the same coupling factor for both windings. Furthermore, the presented serpentine geometry increases performances in terms of magnetic energy density and quality factor, while retaining higher inductance values, at the cost of a limited increase of layout complexity. This paper also provides a more accurate estimation of the inductance of a square-shaped toroidal inductor based on the evaluation of the mean magnetic path length accounting for the non-uniformity of the magnetic flux density in the core cross section and for the corner effect.

A granularity model for balancing the structural complexity of manufacturing systems equipment and layout

The structural complexity of a manufacturing system results primarily from the complexity of its equipment and their layout. The balance between both complexity sources can be achieved by searching for the best system granularity level, which yields a manufacturing system with the least overall structural complexity. A new system granularity complexity index is developed to sum up and normalize the complexity resulting from the system layout complexity and the equipment structural complexity. A previously developed layout complexity index together with a code-based structural complexity assessment are used to determine the structural complexity of standalone pieces of equipment and to arrive at a balance between the two sources of complexity. Cladistics analysis is used to hierarchically cluster required pieces of equipment and bundle them into more integrated equipment and machines and demonstrate the possible different system granularity levels. The new developed model is a useful tool to create specific system configuration and layout alternatives based on system components adjacency, and then select the system design with the least overall structural complexity among those alternatives. The results of the presented case study clearly demonstrated this trade-off where decomposing manufacturing systems into a highly granular configuration with standalone machines maximizes system layout complexity and minimizes equipment complexity, while at a low level of granularity pieces of equipment are bundled into complex integrated machines, lines or cells but with a very simple system layout.

GO: A cluster algorithm for graph visualization

As we are in the big data age, graph data such as user networks in Facebook and Flickr becomes large. How to reduce the visual complexity of a graph layout is a challenging problem. Clustering graphs is regarded as one of effective ways to address this problem. Most of current graph visualization systems, however, directly use existing clustering algorithms that are not originally developed for the visualization purpose. For graph visualization, a clustering algorithm should meet specific requirements such as the sufficient size of clusters, and automatic determination of the number of clusters. After identifying the requirements of clustering graphs for visualization, in this paper we present a new clustering algorithm that is particularly designed for visualization so as to reduce the visual complexity of a layout, together with a strategy for improving the scalability of our algorithm. Experiments have demonstrated that our proposed algorithm is capable of detecting clusters in a way that is required in graph visualization.

An IP-oriented 11-bit 160 MS/s 2-channel current-steering DAC

This paper presents an 11-bit 160 MS/s 2-channel current-steering digital-to-analog converter (DAC) IP. The circuit and layout are carefully designed to optimize its performance and area. A 6-2-3 segmented structure is used for the trade-off among linearity, area and layout complexity. The sizes of current source transistors are calculated out according to the process matching parameter. The unary current cells are placed in a one-dimension distribution to simplify the layout routing, spare area and wiring layer. Their sequences are also carefully designed to reduce integral nonlinearity. The test result presents an SFDR of 72 dBc at 4.88 MHz input signal with DNL ⩽ 0.25 LSB, INL ⩽ 0.8 LSB. The full-scale output current is 5 mA with a 2.5 V analog power supply. The core of each channel occupies 0.08 mm2 in a 1P-8M 55 nm CMOS process.

Wayfinding Behaviors in Complex Buildings

To contribute to a more comprehensive understanding of human wayfinding behaviors in complex buildings, we propose a framework that incorporates the impact of critical factors from both the environment and humans. The influence of the environment is summarized through the concept of environmental legibility (EL), an integration of different space syntax methods that addresses visibility, connectivity, and layout complexity of buildings. Human factors are assessed through psychometric tests, self-ratings for sense of direction, and a report of familiarity. To test this framework, we conducted behavioral experiments involving 24 novices and 28 experts. Three different processes of wayfinding—wayfinding performance, acquisition of spatial knowledge, and development of spatial awareness—were measured and evaluated. Results show that EL and individual differences impact all three processes. There is a predominant impact of EL on wayfinding performance and the development of spatial awareness. Not surprisingly, familiarity has a predominant impact on the acquisition of spatial knowledge.

A Review of Three‐Dimensional Resistive Switching Cross‐Bar Array Memories from the Integration and Materials Property Points of View

Issues in the circuitry, integration, and material properties of the two‐dimensional (2D) and three‐dimensional (3D) crossbar array (CBA)‐type resistance switching memories are described. Two important quantitative guidelines for the memory integration are provided with respect to the required numbers of signal wires and sneak current paths. The advantage of 3D CBAs over 2D CBAs (i.e., the decrease in effect memory cell size) can be exploited only under certain limited conditions due to the increased area and layout complexity of the periphery circuits. The sneak current problem can be mitigated by the adoption of different voltage application schemes and various selection devices. These have critical correlations, however, and depend on the involved types of resistance switching memory. The problem is quantitatively dealt with using the generalized equation for the overall resistance of the parasitic current paths. Atomic layer deposition is discussed in detail as the most feasible fabrication process of 3D CBAs because it can provide the device with the necessary conformality and atomic‐level accuracy in thickness control. Other subsidiary issues related to the line resistance, maximum available current, and fabrication technologies are also reviewed. Finally, a summary and outlook on various other applications of 3D CBAs are provided.

Floor Plan Connectivity Influences Wayfinding Performance in Virtual Environments

The structure of the physical environment can have a significant influence on individuals’ ability to orient within it. We asked participants to perform a cued wayfinding task in two virtual environments to test the hypothesis that spatial orientation skills are indeed affected by the physical complexity of the environment. The two virtual environments used for testing differed solely in one objective measure of plan complexity, that is, the average number of connections at each decision point or terminal corridor. Our results showed that participants committed more errors and took longer to reach their destinations in the more interconnected environment. Performance was more efficient on trials in which participants were able to use previously learned routes relative to trials in which participants were forced to plan novel routes. These findings provide strong evidence that people’s ability to navigate in unfamiliar surroundings is affected by the layout complexity of the environment.

Picturing perspectives: development of perspective-taking abilities in 4- to 8-year-olds.

Although the development of perspective taking has been well researched, there is no uniform methodology for assessing this ability across a wide age span when frames of reference conflict. To address this gap, we created scenes of toy photographers taking pictures of layouts of objects from different angles, and presented them to 4- to 8-year-olds (N = 80). Children were asked to choose which one of four pictures could have been taken from a specific viewpoint. Results showed that this new technique confirmed the classic pattern of developmental progress on this kind of spatial skill: (1) 4-year-olds responded near chance level, regardless of layout complexity, (2) there was a growing ability to inhibit egocentric choices around age 6 with layouts of low complexity (one object), (3) performance increased and egocentric responses decreased dramatically around age 7, (4) even at age 8, children still showed considerable individual variability. This perspective taking task can thus be used to address important questions about the supports for early spatial development and the structure of early intellect.

Texture sparseness for pixel classification of business document images

Contemporary business documents contain diverse, multi-layered mixtures of textual, graphical, and pictorial elements. Existing methods for document segmentation and classification do not handle well the complexity and variety of contents, geometric layout, and elemental shapes. This paper proposes a novel document image classification approach that distributes individual pixels into four fundamental classes (text, image, graphics, and background) through support vector machines. This approach uses a novel low-dimensional feature descriptor based on textural properties. The proposed feature vector is constructed by considering the sparseness of the document image responses to a filter bank on a multi-resolution and contextual basis. Qualitative and quantitative evaluations on business document images show the benefits of adopting a contextual and multi-resolution approach. The proposed approach achieves excellent results; it is able to handle varied contents and complex document layouts, without imposing any constraint or making assumptions about the shape and spatial arrangement of document elements.

Generalizing Geometric Graphs

Network visualization is essential for understanding the data obtained from huge real-world networks such as flight-networks, the AS-network or social networks. Although we can compute layouts for these networks reasonably fast, even the most recent display media are not capable of displaying these layouts in an adequate way. Moreover, the human viewer may be overwhelmed by the displayed level of detail. The increasing amount of data therefore requires techniques aiming at a sensible reduction of the visual complexity of huge layouts. We consider the problem of computing a generalization of a given layout reducing the complexity of the drawing to an amount that can be displayed without clutter and handled by a human viewer. We take a first step at formulating graph generalization within a mathematical model and we consider the resulting problems from an algorithmic point of view. Although these problems are NP-hard in general, we provide efficient approximation algorithms as well as efficient and effective heuristics. At the end of the paper we showcase some sample generalizations.

Fast readout architectures for large arrays of digital pixels: examples and applications.

Modern pixel detectors, particularly those designed and constructed for applications and experiments for high-energy physics, are commonly built implementing general readout architectures, not specifically optimized in terms of speed. High-energy physics experiments use bidimensional matrices of sensitive elements located on a silicon die. Sensors are read out via other integrated circuits bump bonded over the sensor dies. The speed of the readout electronics can significantly increase the overall performance of the system, and so here novel forms of readout architectures are studied and described. These circuits have been investigated in terms of speed and are particularly suited for large monolithic, low-pitch pixel detectors. The idea is to have a small simple structure that may be expanded to fit large matrices without affecting the layout complexity of the chip, while maintaining a reasonably high readout speed. The solutions might be applied to devices for applications not only in physics but also to general-purpose pixel detectors whenever online fast data sparsification is required. The paper presents also simulations on the efficiencies of the systems as proof of concept for the proposed ideas.

Cognitive and Environmental Factors Influencing the Process of Spatial Knowledge Acquisition within Virtual Reality Environments

As the fidelity of virtual environments (VE) continues to increase, the possibility of using them as training platforms is becoming increasingly realistic for a variety of application domains, including military and emergency personnel training. In the past, there was much debate on whether the acquisition and subsequent transfer of spatial knowledge from VEs to the real world is possible, or whether the differences in medium during training would essentially be an obstacle to truly learning geometric space. In this paper, the authors present various cognitive and environmental factors that not only contribute to this process, but also interact with each other to a certain degree, leading to a variable exposure time requirement in order for the process of spatial knowledge acquisition (SKA) to occur. The cognitive factors that the authors discuss include a variety of individual user differences such as: knowledge and experience; cognitive gender differences; aptitude and spatial orientation skill; and finally, cognitive styles. Environmental factors discussed include: Size, Spatial layout complexity and landmark distribution. It may seem obvious that since every individual's brain is unique - not only through experience, but also through genetic predisposition that a one size fits all approach to training would be illogical. Furthermore, considering that various cognitive differences may further emerge when a certain stimulus is present (e.g. complex environmental space), it would make even more sense to understand how these factors can impact spatial memory, and to try to adapt the training session by providing visual/auditory cues as well as by changing the exposure time requirements for each individual. The impact of this research domain is important to VE training in general, however within service and military domains, guaranteeing appropriate spatial training is critical in order to ensure that disorientation does not occur in a life or death scenario.

A model for assessing the layout structural complexity of manufacturing systems

The layout of a manufacturing facility/system not only shapes its material flow pattern and influence transportation and operation cost, but also affects logistics and parts/machine assignment decisions. The layout of manufacturing systems determines its structural complexity by virtue of its design configuration characteristics. This paper introduces a new model and indices for assessing the structural complexity of manufacturing systems layout in the physical domain. Six complexity indices, based on the physical structural characteristics of the layout, have been introduced and formulated. They are layout density, path, cycle, decision points, redundancy distribution and magnitude indices. An overall Layout Complexity Index (LCI) which combines all indices is developed using a novel method based on radar plots which is insensitive to the order of plotting the individual indices. The use of the developed LCI is demonstrated using six typical types of manufacturing systems layouts and relevant guidelines are presented. The developed model and complexity indices help design system layouts for least complexity and compare layout alternatives that meet the specifications, at early design stages. It supports making trade-off decisions regarding manufacturing systems flexibility and complexity and their associated costs.

Minoan Halls: A Syntactical Genealogy

The tripartite room labeled a Minoan hall is probably the most emblematic architectural feature of the Neopalatial period in Bronze Age Crete (1700/1675–1470/ 1460 B.C.E.). Although this spatial arrangement stands out as an exceptional accomplishment because of its elaborate layout, fine materials, and innovative properties, its function is still somewhat enigmatic. In fact, some of its very characteristics, such as flexibility and layout complexity, significantly hinder an in-depth evaluation of the role that Minoan halls played in Late Bronze Age Crete. I argue here that the lack of an exhaustive and systematic analysis of the spatial structure of these tripartite arrangements has hampered our understanding of them and that their architectural development should receive more attention. I present an approach for analyzing the spatial syntax of Minoan halls, their evolution in a diachronic perspective, and their diversity in specific buildings. Far from being yet another attempt to give a clear-cut functional definition of Minoan halls, this research offers instead a new way of considering Minoan architecture.*