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1 – 10 of 529Advanced discrete wiring systems are being developed to produce state‐of‐the‐art circuit boards for packaging the next generation electronic systems. The demands placed on…
Abstract
Advanced discrete wiring systems are being developed to produce state‐of‐the‐art circuit boards for packaging the next generation electronic systems. The demands placed on electronic interconnection by very high speed VLSI devices have created a need for large circuit boards that will support high interconnection density. At the same time these circuit boards must maintain the necessary transmission line parameters to transport signals with sub‐nanosecond rise times and retain signal fidelity.
Shumpei Haginoya, Aiko Hanayama and Tamae Koike
The purpose of this paper was to compare the accuracy of linking crimes using geographical proximity between three distance measures: Euclidean (distance measured by the length of…
Abstract
Purpose
The purpose of this paper was to compare the accuracy of linking crimes using geographical proximity between three distance measures: Euclidean (distance measured by the length of a straight line between two locations), Manhattan (distance obtained by summing north-south distance and east-west distance) and the shortest route distances.
Design/methodology/approach
A total of 194 cases committed by 97 serial residential burglars in Aomori Prefecture in Japan between 2004 and 2015 were used in the present study. The Mann–Whitney U test was used to compare linked (two offenses committed by the same offender) and unlinked (two offenses committed by different offenders) pairs for each distance measure. Discrimination accuracy between linked and unlinked crime pairs was evaluated using area under the receiver operating characteristic curve (AUC).
Findings
The Mann–Whitney U test showed that the distances of the linked pairs were significantly shorter than those of the unlinked pairs for all distance measures. Comparison of the AUCs showed that the shortest route distance achieved significantly higher accuracy compared with the Euclidean distance, whereas there was no significant difference between the Euclidean and the Manhattan distance or between the Manhattan and the shortest route distance. These findings give partial support to the idea that distance measures taking the impact of environmental factors into consideration might be able to identify a crime series more accurately than Euclidean distances.
Research limitations/implications
Although the results suggested a difference between the Euclidean and the shortest route distance, it was small, and all distance measures resulted in outstanding AUC values, probably because of the ceiling effects. Further investigation that makes the same comparison in a narrower area is needed to avoid this potential inflation of discrimination accuracy.
Practical implications
The shortest route distance might contribute to improving the accuracy of crime linkage based on geographical proximity. However, further investigation is needed to recommend using the shortest route distance in practice. Given that the targeted area in the present study was relatively large, the findings may contribute especially to improve the accuracy of proactive comparative case analysis for estimating the whole picture of the distribution of serial crimes in the region by selecting more effective distance measure.
Social implications
Implications to improve the accuracy in linking crimes may contribute to assisting crime investigations and the earlier arrest of offenders.
Originality/value
The results of the present study provide an initial indication of the efficacy of using distance measures taking environmental factors into account.
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The purpose of this paper is to provide a historical perspective and framework for appreciating the evolution of 3D interconnection technologies from past to present.
Abstract
Purpose
The purpose of this paper is to provide a historical perspective and framework for appreciating the evolution of 3D interconnection technologies from past to present.
Design/methodology/approach
A literature and patent search was performed to find the origins of 3D interconnections to find and credit work that was performed in the early electronics industry which presaged the development of the current generation 3D solutions.
Findings
The origins of 3D interconnections have roots that date to the beginnings of electronic interconnections if the earlier solutions are viewed in proper perspective. For example, early telegraphy and telephony interconnections strung from pole to pole across large expanses of terrain were clearly 3D interconnections on a very macro scale but those solutions scaled down are not that dissimilar to what is being done today in some advanced interconnection technologies.
Research limitations/implications
The pioneers of the electronics industry broke a trail which has been widened, paved and branched by all who have followed them. Granted that the branches have led to new high‐worth discoveries but acknowledging the past and taking instruction from it is important, even necessary, to assure that future developments do not continually “reinvent the wheel”.
Originality/value
The paper traces, in brief fashion, the history of 3D interconnections providing examples of solutions which predate some of the current generation solutions which appear, in some cases, quite similar to those developed or proposed nearly half century ago. Knowing the past is vital to understanding and shaping the future.
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In the mid-2000s, the operator of New York City’s mass transit network committed more than a half-billion dollars to military contractor Lockheed Martin for a security technology…
Abstract
In the mid-2000s, the operator of New York City’s mass transit network committed more than a half-billion dollars to military contractor Lockheed Martin for a security technology capable, in part, of inferring threats based on analysis of data streams, of developing response strategies, and taking automated action toward alerts and calamities in light of evolving circumstances. The project was a failure. This chapter explores the conceptualization and development of this technology – rooted in cybernetics – and compares its conceptual underpinnings with some situated problems of awareness, communication, coordination, and action in emergencies as they unfold in one of the busiest transport systems in the world, the New York subway. The author shows how the technology, with all the theatrical trappings of a “legitimate” security solution, was apparently conceived without a grounded understanding of actual use-cases, and the degree to which the complex interactions which give rise to subway emergency can be anticipated in – and therefore managed through – a technological system. As a case-study, the chapter illustrates the pitfalls of deploying technology against problems which are not well-defined in the first place, to the neglect of investments against much more fundamental problems – such as inadequate communication systems, and unstable relationships with emergency response agencies – which might offer guaranteed benefits, and indeed lay a firm groundwork for future deployment of more ambitious technology.
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Narelle Haworth and Jacqueline Fuller
Purpose – Bicycle riding provides a sustainable and affordable solution to many of the significant problems associated with motorised transport and physical inactivity. The…
Abstract
Purpose – Bicycle riding provides a sustainable and affordable solution to many of the significant problems associated with motorised transport and physical inactivity. The provision of infrastructure plays an important role in encouraging people to begin and subsequently continue to ride bicycles and to do so safely.
Methodology – This chapter describes different types of on- and off-road infrastructure and reviews studies of their effects on rider numbers and safety. In addition, it looks at the roles that end-of-trip facilities and bikeshare programs can play in contributing to bicycle use and general transport sustainability.
Findings – Infrastructure characteristics can influence both perceived and objective levels of safety. It is important to identify and avoid treatments that increase perceived safety but are actually less safe. The type of infrastructure needed or desired differs between current and potential riders and according to trip purpose. Well-designed marked bicycle lanes on roads can reduce crash rates. Safety at intersections can be improved by: advanced green lights for cyclists, short cuts for right-hand turns, brightly coloured bicycle paths and advanced waiting positions for cyclists. Off-road facilities are generally safer, but intersections with roads must be carefully treated. Shared paths and footpaths are risky for older pedestrians (and older cyclists).
Implications – In many countries the provision of more infrastructure that increases the perceived safety of riding is needed to encourage cycling, particularly transport cycling and cycling by women.
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The purpose of this paper is to develop a new rectilinear branch pipe‐routing algorithm for automatic generation of rectilinear branch pipe routes in constrained spaces of…
Abstract
Purpose
The purpose of this paper is to develop a new rectilinear branch pipe‐routing algorithm for automatic generation of rectilinear branch pipe routes in constrained spaces of aero‐engines.
Design/methodology/approach
Rectilinear branch pipe routing that connects multiple terminals in a constrained space with obstacles can be formulated as a rectilinear Steiner minimum tree with obstacles (RSMTO) problem while meeting certain engineering rules, which has been proved to be an NP‐hard and discrete problem. This paper presents a discrete particle swarm optimization (PSO) algorithm for rectilinear branch pipe routing (DPSO‐RBPRA) problems, which adopts an attraction operator and an energy function to plan the shortest collision‐free connecting networks in a discrete graph space. Moreover, this paper integrates several existing techniques to evaluate particles for the RSMTO problem in discrete Manhattan spaces. Further, the DPSO‐RBPRA is extended to surface cases to adapt to requirements of routing pipes on the surfaces of aero‐engines.
Findings
Pipe routing numeral computations show that, DPSO‐RBPRA finds satisfactory connecting networks while considering several engineering rules, which demonstrates the effectiveness of the proposed method.
Originality/value
This paper applies the Steiner tree theory and develops a DPSO algorithm to plan the aero‐engine rectilinear branch pipe‐routing layouts.
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Happy Holden and Richard Charbonneau
This paper reveals a new methodology for predicting the most efficient design rules to follow for high density printed wiring boards prior to physical layout. The only input is…
Abstract
This paper reveals a new methodology for predicting the most efficient design rules to follow for high density printed wiring boards prior to physical layout. The only input is from a schematic diagram, parts list and proposed board size. The methodology attempts to a priori determine the wiring capabilities of different PWB designs for a given product application. The particular focus is the difference between through‐hole and HDI designs.
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Andrzej Kos and Zbigniew Nagórny
The aim of this work is to examine the Hopfield network for the field programmable gate array (FPGA) cell placement.
Abstract
Purpose
The aim of this work is to examine the Hopfield network for the field programmable gate array (FPGA) cell placement.
Design/methodology/approach
Implementation of an algorithm in FPGA circuits requires synthesis, placement and the routing of logic cells. The placement takes the longest time for computation. Therefore, an algorithm for a run‐time reconfigurable system can be chosen from among earlier prepared algorithms. This paper presents a Hopfield neural network for solving the placement problem. The Hopfield network was also used for processing units in a parallel placement. Hardware implementation of presented solutions could accelerate the FPGA placement by orders of magnitude in comparison with placers executed on traditional computers. Hardware accelerators could also be applied to the design of other VLSI circuits. The simulation results for the FPGA placement are presented.
Findings
The Hopfield network and parallel placement give comparable placements with the method using a simulated annealing algorithm. The parallel placement enables a decrease in total number of neurons and neuron connections which are necessary for simultaneous placement of all cells in a circuit.
Research limitations/implications
This work provides a starting‐point for further research under hardware realization of the cell placement by using the Hopfield network. The presented solutions can be used for FPGA, gate array, sea‐of‐gates circuits and standard cell circuits with the same size cells.
Originality/value
The Hopfield network is used for placement in real circuits, in which nets contain multiple terminals, and for processing units in a parallel placement.
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