A solid state Marx generator with a novel configuration

The new configuration proposed in this paper for Marx Generator (MG.) aims to generate high voltage for pulsed power applications through reduced number of semiconductor components with a more efficient load supplying process. The main idea is to charge two groups of capacitors in parallel through an inductor and take the advantage of resonant phenomenon in charging each capacitor up to a double input voltage level. In each resonant half a cycle, one of those capacitor groups are charged, and eventually the charged capacitors will be connected in series and the summation of the capacitor voltages can be appeared at the output of the topology. This topology can be considered as a modified Marx generator which works based on the resonant concept. Simulated models of this converter have been investigated in Matlab/SIMULINK platform and the acquired results fully satisfy the anticipations in proper operation of the converter

On-line privacy behavior: using user interfaces for salient factors

The problem of privacy in social networks is well documented within literature; users have privacy concerns however, they consistently disclose their sensitive information and leave it open to unintended third parties. While numerous causes of poor behaviour have been suggested by research the role of the User Interface (UI) and the system itself is underexplored. The field of Persuasive Technology would suggest that Social Network Systems persuade users to deviate from their normal or habitual behaviour. This paper makes the case that the UI can be used as the basis for user empowerment by informing them of their privacy at the point of interaction and reminding them of their privacy needs. The Theory of Planned Behaviour is introduced as a potential theoretical foundation for exploring the psychology behind privacy behaviour as it describes the salient factors that influence intention and action. Based on these factors of personal attitude, subjective norms and perceived control, a series of UIs are presented and implemented in controlled experiments examining their effect on personal information disclosure. This is combined with observations and interviews with the participants. Results from this initial, pilot experiment suggest groups with privacy salient information embedded exhibit less disclosure than the control group. This work reviews this approach as a method for exploring privacy behaviour and proposes further work required

Digital libraries: What do users want?

This is the post-print version of the Article of the Article. The official published version can be accessed from the link below - Copyright @ 2006 EmeraldPurpose – The purpose of this study is to determine user suggestions for digital libraries' functionality and features. Design/methodology/approach – A survey was conducted as part of this study, in which users' suggestions for digital libraries were solicited, as well as their ranking opinions on a range of suggested digital library features. Findings – The study revealed that, regardless of users' information technology (IT) backgrounds, their expectations of digital libraries' functionality are the same. However, based on users' previous experiences with digital libraries, their requirements with respect to specific features may change. Practical implications – Involving users in digital library design should be an integral step in the process of building a digital library – in addition to the classic roles of evaluation and testing. Originality/value – In previous digital library user studies, users were involved implicitly (e.g. observed) or explicitly (e.g. diary notes). However, they were never asked to suggest digital library features or functionalities, as this was left to usability and domain experts. This study approached digital library design from a new perspective, giving users an opportunity to express their suggestions on future functionality and features of digital libraries. Moreover, in contrast to previous work, this study has explicitly taken into account the IT abilities of those interacting with a digital library

Investigation of a proposed long span timber floor for non-residential applications

University of Technology, Sydney. Faculty of Engineering and Information Technology.Design of floor systems for commercial and multi-residential buildings in many parts of the world is currently dominated by the use of structural materials other than timber, such as reinforced concrete systems. Recent research in Australia has shown that the major barriers to using timber in non-residential buildings are the fire performance and the lack of designer confidence in commercial and industrial timber-based constructions. In this regard, significant research initiatives have commenced in Australia and New Zealand with the aim of developing timber and timber hybrid systems for large span commercial and industrial applications. This PhD research provides a detailed procedure for designing and investigating the short term static behaviour of a proposed long span timber floor system for non-residential applications that meets serviceability and ultimate limit design criteria, with the use of timber as the only structural load bearing part of the system. The specimen’s responses to long-term loading, in-plane loading, dynamic excitation, cyclic loading and loading history are outside the scope of this PhD research. Moreover, other aspects of performance such as assessment of acoustic performance, dynamic performance and the possible interconnection systems alongside floor modules are not covered in the scope of this research project. In this study the behaviour of two types of LVL are investigated through a number of experimental and analytical tests. As a result of the tension and compression tests, a suitable constitutive law is developed which can accurately capture the stress-strain relationship and the failure behaviour of LVL, and it can also be incorporated into FE analysis of any LVL beam with similar structural features to the tested specimens. Further, the results of the full scale four point bending tests on LVL sections are used to identify the behaviour of LVL up to the failure point and to develop a finite element model to capture the behaviour and failure of LVL. Moreover, after investigating the long span timber floors, one system is proposed to be fabricated for the extensive experimental and numerical investigation. The experimental investigation involved subjecting the full scale proposed floor modules (6m and 8m clear span LVL modules) to both serviceability and ultimate limit state static loading to assess the strength and serviceability performance of the proposed system. A continuum-based finite element model is also developed to capture the behaviour and failure of the long span LVL modules and to adequately predict the serviceability and ultimate limit performance of the proposed floor system. To evaluate the partially-composite strength and serviceable performance of LVL floor system, a series of push-out tests are conducted on the fabricated timber connections using normal screws as the shear connectors, and the stiffness of the connections are assessed at serviceability and ultimate limit state. A number of LVL beams (3.5m “T” shaped beams) were also fabricated using only normal screws as the load bearing shear connectors at the interfaces, and are tested under serviceability and ultimate limit state loads with different screw spacing. Furthermore, a closed-form prediction analysis is conducted to calculate the partially-composite ultimate load of the beams. A comparison between the experimental results and the closed-from predicted results is undertaken, and the results are used for predicting the partially-composite behaviour of long span 6m and 8m LVL modules. The results of the full scale experimental tests together with the numerical investigation provide a robust model for predicting the performance of any timber beams with similar structural features to the proposed system while the dimensions and spans can be varied according to special requirements such as dynamic performance or fire resistance requirements

Detection and Recognition of Traffic Signs Inside the Attentional Visual Field of Drivers

Traffic sign detection and recognition systems are essential components of Advanced Driver Assistance Systems and self-driving vehicles. In this contribution we present a vision-based framework which detects and recognizes traffic signs inside the attentional visual field of drivers. This technique takes advantage of the driver\u27s 3D absolute gaze point obtained through the combined use of a front-view stereo imaging system and a non-contact 3D gaze tracker. We used a linear Support Vector Machine as a classifier and a Histogram of Oriented Gradient as features for detection. Recognition is performed by using Scale Invariant Feature Transforms and color information. Our technique detects and recognizes signs which are in the field of view of the driver and also provides indication when one or more signs have been missed by the driver

A comparative investigation into knowledge of object attributes of name, unique function and category membership, in healthy elders and older people with Alzheimer-type dementia

The progressive lexical-semantic deterioration which accompanies dementia of the Alzheimer type (DAT) has been highlighted by recent explorations of knowledge of object attributes, object naming, and recognition of object categories. An Experimental Battery for Semantic Processing devised for this research comprised six tests examining these semantic skills in older people with probable Alzheimer-type dementia at very mild to moderate levels of severity. An innovative set of sixty 'unique feature' or distinctive attribute cues were utilised in a recognition test of concrete nouns from fifteen common semantic categories. The recognition test, presented in both picture and written form, verified that specific attributes were more successful than semantic category in facilitating lexical comprehension in older people with DAT. A naming test afforded the opportunity to evaluate the efficacy of the unique feature cues in facilitating name recall for the noun set. The DAT participants utilised the attribute cues to enable object naming, despite measurable deficits in cognitive and linguistic processing abilities. These findings therefore highlight the potential clinical application of semantic cueing techniques in aiding name recall with this client group. A generative naming test further verified a residual 'core' vocabulary, within each of the fifteen semantic categories, which remained resistant to disease progression in the DAT participants. However, the finding that DAT participants were less successful in accessing broader category information contrasts with reports in the recent literature and warrants further investigation. The performance of the Control subjects, representing healthy elders aged from 65 to 85+ years, confirmed the resistance to advancing chronological age of every lexical test in the Experimental Battery for Semantic Processing. The Standard Measures Battery for Cognitive and Language Function, a screening battery of six cognitive and language tests also compiled for the research, verified that the DAT group were performing at levels significantly below the baseline established by the Controls on every measure. Nevertheless, the DAT participants maintained comparative levels of performance on the semantic tests after an interval of mean nine months, demonstrating the resistance of these lexical measures to advancing duration and severity of disease

Developing Predictive Models of Driver Behaviour for the Design of Advanced Driving Assistance Systems

World-wide injuries in vehicle accidents have been on the rise in recent years, mainly due to driver error. The main objective of this research is to develop a predictive system for driving maneuvers by analyzing the cognitive behavior (cephalo-ocular) and the driving behavior of the driver (how the vehicle is being driven). Advanced Driving Assistance Systems (ADAS) include different driving functions, such as vehicle parking, lane departure warning, blind spot detection, and so on. While much research has been performed on developing automated co-driver systems, little attention has been paid to the fact that the driver plays an important role in driving events. Therefore, it is crucial to monitor events and factors that directly concern the driver. As a goal, we perform a quantitative and qualitative analysis of driver behavior to find its relationship with driver intentionality and driving-related actions. We have designed and developed an instrumented vehicle (RoadLAB) that is able to record several synchronized streams of data, including the surrounding environment of the driver, vehicle functions and driver cephalo-ocular behavior, such as gaze/head information. We subsequently analyze and study the behavior of several drivers to find out if there is a meaningful relation between driver behavior and the next driving maneuver

Gray wolves adjust their spatial and social environments according to prey distributions in a multi-prey system

Animals modify their environment through movement to increase their success in acquiring energy. This may be done by selecting spaces to increase encounter rates with prey through different space use tactics, or in the case of social carnivores, adjusting social environments to balance the tensions associated with capturing prey and sharing the acquired energy with conspecifics. I tested hypotheses on how social predators select space based on three prey distribution metrics, and how they subsequently adjust their level of cohesion with conspecifics based on prey distribution. I tested these hypotheses in Riding Mountain National Park, Manitoba, a multi-prey system where gray wolves (Canis lupus) prey on moose (Alces alces), elk (Cervus canadensis), white-tailed deer (Odocoileus virginianus) and beaver (Castor canadensis). I found evidence that wolves used the predicted space use tactic for their primary prey species and adjust their level of cohesion based on the distribution of moose and beaver