BCIT Citations Collection | BCIT Institutional Repository

BCIT Citations Collection

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Collection of published works from BCIT researchers, faculty, and instructors.

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Community Energy Storage impacts on smart grid adaptive Volt-VAR Optimization of distribution networks
Accepted in 7th International Symposium on Power Electronics for Distributed Generation Systems (PEDG 2016), Jun. 2016, Vancouver, BC, Canada. This paper aims to investigate Community Energy Storage (CES) impacts on AMI-based Volt-VAR Optimization (VVO) solutions for advanced distribution networks. CES is one of the technologies employed to improve system stability, reliability and quality. As such, it could have considerable impacts on voltage control, reactive power optimization and energy conservation. Conservation Voltage Reduction (CVR) is one of the main tasks of advanced VVO engines in distribution networks. Moreover, in order to check the performance of the discussed VVO engine in the presence of CES during peak time intervals, 33-node distribution feeder is employed. The results of this paper show significant improvement in the performance of the VVO engine when CES is forced to discharge in peak times. Moreover, the results present how CES could affect Volt-VAR Control Component (VVCC) switching and how it affects the energy conservation efficiency., Conference paper, Published.
Concept proposal for a detachable exoskeleton-wheelchair to improve mobility and health
Proceedings of 2013 IEEE International Conference on Rehabilitation Robotics, June 24-26, 2013 Seattle, Washington USA. Wheelchair use has consequences to quality of life in at least two areas: 1) health issues such as pressure sores and chronic overuse injury; and 2) access problems due to the inaccessible nature of the built and natural environments that are most amenable to upright postures. Even with these concerns, wheelchairs are still the best form of mobility for many people (e.g. they are relatively easy to transfer into and propel). However, wheelchairs are simply not transformative, i.e. they do not allow a person with a disability to attain a level of mobility performance that approaches that of their non-disabled peers, nor do they typically allow for face to face interactions and full participation in the community. Wheelchairs also do not typically support ongoing therapeutic benefits for the user. To address the inadequacy of existing wheelchairs, we are merging two evolving technologies into a coherent new mobility device. The first is dynamic wheeled mobility, which adds significant functionality to conventional wheelchairs through the use of on-the-fly adjustable positioning. The second is powered walking exoskeletons, which enable highly desired standing and walking functions, as well as therapeutic benefits associated with rehabilitation gait training. Unfortunately, exoskeletons have significant usability concerns such as slow speed, limited range, potential to cause skin issues, and difficult transfers. A new concept of docking a detachable exoskeleton to a wheeled frame has been developed to address these issues. The design goal is a single mobility device that not only optimizes daily activities (i.e. wheelchair seating and propulsion with dynamic positioning), but also serves as an easy-to-use rehabilitation tool for therapeutic benefits (i.e. a detachable powered exoskeleton for walking sojourns). This has significant potential benefits for the lives of people with mobility impairments., Conference paper, Published.
A declarative model for reasoning about form security
Proceedings of the International Conference on Agents and Artificial Intelligence in Lisbon, Portugal 2015. We introduce a formal methodology for analysing the security of digital forms, by representing form signing procedures in a declarative action formalism. In practice, digital forms are represented as XML documents and the security of information is guaranteed through the use of digital signatures. However, the security of a form can be compromised in many different ways. For example, an honest agent might be convinced to make a commitment that they do not wish to make or they may be fooled into believing that another agent has committed to something when they have not. In many cases, these attacks do not require an intruder to break any form of encryption or digital signature; instead, the intruder simply needs to manipulate the way signatures are applied and forms are passed between agents. In this paper, we demonstrate that form signing procedures can actually be seen as a variation of the message passing systems used in connection with cryptographic protocols. We start with an exis ting declarative model for reasoning about cryptographic protocols in the Situation Calculus, and we show how it can be extended to identify security issues related to digital signatures, and form signing procedures. We suggest that our results could be used to help users create secure digital forms, using tools such as IBM’s Lotus Forms software., Conference paper, Published.
Design, learn, and play
Proceedings of 2015 Annual Meeting of the American Educational Research Association, Chicago, Illinois, 2015. Evidence suggests that computer game-based learning (GBL) environments are effective in increasing students’ motivation and supporting learning (de Freitas, 2013; Kiili, Ketamo, Koivisto, & Finn, 2014; Spires, Rowe, Mott, & Lester, 2011). Many intelligent tutoring systems and advanced learning technologies are designed as educational games (Aleven, Beal, & Graesser, 2013; Conati, Jaques, & Muir, 2013; Rodrigo, et al., 2012). This paper presents the lessons learned during the design, implementation and evaluation of an educational game, Heroes of Math Island, for students in grades five through seven. The game was designed and implemented with the purpose of researching (1) affective states that are relevant to learning during gameplay and (2) methods that are better suited for design of engaging educational games. This paper focuses on the second objective., Conference paper, Published., Peer reviewed
Designing an educational game (Heroes of Math Island)
Proceedings of the 2014 Annual Meeting of the American Educational Research Association, Philadelphia, Pennsylvania. In response to the need for more empirical research with respect to emotion and learning, this study provided an empirical investigation of the students’ interaction with an educational game, Heroes of Math Island, specifically designed for this study. The purpose of this study was to explore learners’ emotional states triggered during gameplay with the goal of providing critical information needed for the design of advanced learning technologies (ALTs) and intelligent tutoring systems (ITSs). The study used the design-based research (DBR) paradigm by combining exploration with design, and mixed methodologies including: pretest, intervention (gameplay), posttest, post-questionnaire, and interview. Fifteen students (seven boys and eight girls) from grades six and seven participated in this study. Findings report on heuristics of educational technology design, emotion, and learning., Conference paper, Published., Peer reviewed
Developing safe fall strategies for lower limb exoskeletons
Proceedings of the 2017 International Conference on Rehabilitation Robotics (ICORR) QEII Centre, London, UK, July 17-20, 2017. One of the main challenges in the use of a powered lower limb exoskeleton (LLE) is to ensure that balance is maintained throughout the operation of the device. Since no control strategy has yet been implemented that prevents falls in the case of a loss of balance, head or other serious injuries may occur during independent use of LLEs in the event of a fall. These safety concerns limit LLEs in the community to supervised use only. Using the backward fall as a model, we used optimization techniques to develop safe fall control strategies in order to avoid head impact and mitigate the impact velocity of the hips. From available human biomechanics data, we first developed an optimization methodology to study falls of healthy people. The results showed similar kinematic and dynamic characteristics to findings of previous studies on real-life human falls. Second, we extended the optimization methodology to include characteristics of a hypothetical LLE and to generate optimal joint trajectories and optimal torque profiles for the fall duration. The results revealed that by applying the optimal fall strategy, the severity of a simulated fall was minimized compared to when the device fell with locked joints (i.e., how currently used exoskeletons fall): head impact was avoided and hip impact velocity was reduced by more than 50%., Conference paper, Published.
Development and benchmarking of a new hygrothermal model
Proceedings of 11th International Conference on Durability of Building Materials and Components: 11 May 2008, Istanbul, Turkey. This paper presents a new hygrothermal model (HAMFit) for simulating the transport of heat, air and moisture across building envelopes. The model is based on partial differential equations solved simultaneously for air velocity, temperature, and moisture distributions for given interior and exterior conditions using finite-element-based commercial software called COMSOL Multiphysics and MatLab. The model is benchmarked using internationally-published numerical model test cases., Conference paper, Published. A version of this document is published in: 11th International Conference on Durability of Building Materials and Components, Istanbul, Turkey, May 11-14, 2008, pp. 1-8.
Development and evaluation of a compliance-independent pressure transducer for biomedical applications
Proceedings of 17th International Conference of the Engineering in Medicine and Biology Society, Montreal, Quebec, Canada, on 20-23 Sept. 1995. The measurement of pressure at a device/tissue interface is desirable in many biomedical engineering applications such as tourniquets and mammography in order to optimize the design or performance of the device. Testing of a selection of existing interface transducers has demonstrated that many are dependent on device and tissue compliance. Such a transducer is only useful in an application where it has been calibrated for specific device/tissue compliance combinations. To overcome this limitation the authors have developed an interface pressure transducer whose output signal is not affected by changes in interface compliance. This enables the transducer to quantitatively measure pressure in many applications without the need to calibrate the transducer for varying compliance conditions. The signal from such a transducer could be incorporated into a control system to measure and control the pressure applied by a mammography machine to the breast., Conference paper, Published.
Development and pilot testing of a kneeling ultralight wheelchair design
Proceedings of 2015 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), Milan, Italy, Aug 25-29 2015. "Dynamic wheeled mobility" offers "on the fly" seating adjustments for wheelchair users such that various activities performed throughout the day can be matched by an appropriate seat position. While this has benefits for user participation and health, the added weight in existing dynamic wheelchairs may impact the user's ability to transport the frame, e.g. into cars. Other dynamic features to enable more participation avenues are also desirable. This paper outlines the development of a "kneeling" ultralight wheelchair design that offers dynamic wheeled mobility functionality at a weight that is comparable to many existing ultralight wheelchairs. In addition, the wheelchair's kneeling function allows a lowered seat position to facilitate low-to-the-ground tasks such as floor transfers and other activities where sustained low level reaching may be required (e.g. playing with children, changing a tire, etc.). This paper also describes the development and pilot testing of an end user evaluation protocol designed to validate the wheelchair's functionality and performance. Successful realization and commercialization of the technology would offer a novel product choice for people with mobility disabilities, and that may support daily activities, health, improved quality of life, and greater participation in the community., Conference paper, Published.
Development of a micromachined pressure transducer for biomedical device/tissue interfaces
Proceedings of 1996 Canadian Conference on Electrical and Computer Engineering, Calgary, Alberta on 26-29 May 1996. In many medical situations, the need for measuring the pressure applied to a tissue quickly and accurately is crucial. Most conventional devices do not measure the actual pressure applied to the tissue because they do not compensate for the tissue or device compliance characteristics and need to be calibrated for each measurement environment. Neuromuscular damage may occur if too much pressure is applied to a tissue for an extended period of time in applications such as tourniquet systems. Incorrect diagnosis may occur if too little pressure is applied in applications such as mammography units. A compliance-independent pressure transducer has other biomedical applications in surgical retraction devices and prosthetic sockets. To eliminate the compliance problem, a pressure transducer was developed using bulk micromachining technology., Conference paper, Published.
The development of an ultralight wheelchair with dynamic seating
Proceedings of the Rehabilitation Engineering and Assistive Technology Society of North America Annual Conference 2011. The Elevation™ wheelchair was recently developed and introduced to the market as an alternative to conventional ultralight rigid wheelchairs normally used by paraplegics and others with disabilities necessitating the daily use of a manual wheelchair. The Elevation wheelchair provides independent user-adjustable seat positioning during normal usage. Elevation allows the user to quickly and easily adjust in real-time the seat height, as well as backrest recline angle, all in a manual ultralight rigid wheelchair form factor. This allows for dynamic seat positioning to suit the tasks and comfort of users throughout their daily activities. The rationale for and user-driven development of the Elevation wheelchair is summarized here., Conference paper, Published.
Dynamic wheeled mobility
31st International Seating Symposium, Nashville, TN, February 26-28, 2015. The prevalence of upper limb pain in full-time manual wheelchair users living with SCI is estimated to be anywhere from 30-70%. For those who rely on an ultralight wheelchair for their day-to-day function, the consequences can be significant and will impact more than just their mobility. Since they were published in 2005, the Clinical Practice Guidelines for Preservation of Upper Limb Function Following Spinal Cord Injury (CPG’s) have served as a valuable evidence-based resource for clinicians and seating/wheeled mobility professionals who work with the SCI population. The recommendations related to wheelchair use are based on extensive research that has examined the effects of the wheelchair’s configuration and the user’s propulsion technique on upper limb function. The recommendations focus on three general areas: Ergonomics, Equipment Selection, and Training., Conference paper, Published.
Early developmental activities and computing proficiency
Proceedings from the 2017 ITiCSE Conference on Working Group Reports. As countries adopt computing education for all pupils from primary school upwards, there are challenging indicators: significant proportions of students who choose to study computing at universities fail the introductory courses, and the evidence for links between formal education outcomes and success in CS is limited. Yet, as we know, some students succeed without prior computing experience. Why is this? Some argue for an innate ability, some for motivation, some for the discrepancies between the expectations of instructors and students, and some -- simply -- for how programming is being taught. All agree that becoming proficient in computing is not easy. Our research takes a novel view on the problem and argues that some of that success is influenced by early childhood experiences outside formal education. In this study, we analyzed over 1300 responses to a multi-institutional and multi-national survey that we developed. The survey captures enjoyment of early developmental activities such as childhood toys, games and pastimes between the ages 0 --- 8 as well as later life experiences with computing. We identify unifying features of the computing experiences in later life, and attempt to link these computing experiences to the childhood activities. The analysis indicates that computing proficiency should be seen from multiple viewpoints, including both skill-level and confidence. Our analysis is the first to show, we believe, that particular early childhood experiences are linked to parts of computing proficiency, namely those related to confidence with problem solving using computing technology. These are essential building blocks for more complex use. We recognize issues in the experimental design that may prevent our data showing a link between early activities and more complex computing skills, and suggest adjustments for future studies. Ultimately, we expect that this line of research will feed in to early years and primary education, and thereby improve computing education for all., Peer reviewed, Conference paper, Published.
EE13-2 development and benchmarking of a new whole building hygrothermal model
Proceedings of Building Enclosure Science & Technology (BEST2) Conference, Portland, USA, April 12-14, 2010. During design process, building engineers evaluate the performance of various design alternatives in terms of their durability, comfort and indoor air quality, as well as energy efficiency using building envelope, indoor and energy analysis tools, respectively. But, usually the analysis tools are in the form of stand-alone package, where there is no direct link among them but rather simplifying assumptions are made on the other two when designing for one. In this paper, the development and benchmarking of a newly developed whole building hygrothermal model are presented. The model considers the building as a system and accounts for the dynamic heat, air and moisture (HAM) interaction between building envelope components and indoor environmental conditions including HVAC systems, moisture and heat sources. The methodology adopted in this work is to develop and validate two primary models: building envelope and indoor models independently and couple them to form the whole building hygrothermal model. After successful integration of the models, the whole building hygrothermal model is benchmarked against internationally published numerical and experimental test results. The holistic model can be used to assess building enclosures durability, indoor conditions (temperature and relative humidity), occupant comfort, and energy efficiency of a building in an integrated manner., Conference paper, Published.
The effects of structural cracking on carbonation progress in reinforced concrete
Proceedings of 3rd International Conference on the Durability of Concrete Structures, 17-19 September 2012, Queen’s University Belfast. There is nearly unanimous consensus among scientists that increasing greenhouse gas emissions, including CO2 generated by human activity, are affecting the Earth’s climate. One essential area which will be affected is the durability of concrete infrastructure. Past research indicates that climate change will exacerbate the rate of carbonation of reinforced concrete structures, potentially leading to premature corrosion of embedded rebar. Cracking of the covering concrete could further increase carbonation rates, but the extent of the increase is unknown. The purpose of this study is to investigate the carbonation of cracked concrete under accelerated test conditions, and to numerically model the movement of the carbonation front in cracked concrete using the concept of effective diffusivity. It was found that the presence of a deep structural crack in a concrete specimen greatly increases the rate of carbonation, possibly leading to premature, localized corrosion within the specimen. The effect of cracks is likely to be much greater than the effect of increased temperatures and increased atmospheric CO2 concentrations. As a result, emphasis must be placed on designing durable infrastructure and following proper maintenance practices so that cracks are less likely to form, thereby extending the longevity of the structure in question., Conference paper, Published.
Emotional design
Proceedings from the First Biannual Conference on Technological Learning and Thinking: Culture, Design, Sustainability, Human Ingenuity held in Vancouver, BC, Canada, 2010., Not peer reviewed, Conference paper

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