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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Evolution in silico of genes with multiple regulatory modules on the example of the Drosophila segmentation gene hunchback
Proceedings of 2012 IEEE Symposium on Computational Intelligence in Bioinformatics and Computational Biology (CIBCB) on 9-12 May 2012 in San Diego, CA, USA. We use in silico evolution to study the generation of gene regulatory structures. A particular area of interest in evolutionary development (evo-devo) is the correspondence between gene regulatory sequences on the DNA (cis-regulatory modules, CRMs) and the spatial expression of the genes. We use computation to investigate the incorporation of new CRMs into the genome. Simulations allow us to characterize different cases of CRM to spatial pattern correspondence. Many of these cases are seen in biological examples; our simulations indicate relative advantages of the different scenarios. We find that, in the absence of specific constraints on the CRM-pattern correspondence, CRMs controlling multiple spatial domains tend to evolve very quickly. Genes constrained to a one-to-one CRM-pattern domain correspondence evolve more slowly. Of these, systems in which pattern domains appear in a particular order in evolution, as in insect segmentation mechanisms, take the longest time in in silico evolutionary searches. For biological cases of this type, it is likely that other selective advantages outweigh the time costs., Conference paper, Published.
Experimental determination of intrinsic drosophila embryo coordinates by evolutionary computation
Proceedings of 8th IAPR International Conference, PRIB 2013, Nice, France, June 17-20, 2013. Early fruit fly embryo development begins with the formation of a chemical blueprint that guides cellular movements and the development of organs and tissues. This blueprint sets the intrinsic spatial coordinates of the embryo. The coordinates are curvilinear from the start, becoming more curvilinear as cells start coherent movements several hours into development. This dynamic aspect of the curvature is an important characteristic of early embryogenesis: characterizing it is crucial for quantitative analysis and dynamic modeling of development. This presents a number of methodological problems for the elastic deformation of 3D and 4D data from confocal microscopy, to standardize images and follow temporal changes. The parameter searches for these deformations present hard optimization problems. Here we describe our evolutionary computation approaches to these problems. We outline some of the immediate applications of these techniques to crucial problems in Drosophila developmental biology., Conference paper, Published.
An explicit model of belief change for cryptographic protocol verification
Proceedings of the 8th International Symposium on Logical Formalizations of Commonsense Reasoning. Stanford, CA, 2007. Cryptographic protocols are structured sequences of messages that are used for exchanging information in a hostile environment. Many protocols have epistemic goals: a successful run of the protocol is intended to cause a participant to hold certain beliefs. As such, epistemic logics have been employed for the verification of cryptographic protocols. Although this approach to verification is explicitly concerned with changing beliefs, formal belief change operators have not been incorporated in previous work. In this preliminary paper, we introduce a new approach to protocol verification by combining a monotonic logic with a non-monotonic belief change operator. In this context, a protocol participant is able to retract beliefs in response to new information and a protocol participant is able to postulate the most plausible event explaining new information. Hence, protocol participants may draw conclusions from received messages in the same manner conclusions are drawn in formalizations of commonsense reasoning. We illustrate that this kind of reasoning is particularly important when protocol participants have incorrect beliefs., Conference paper, Published.
Exploiting known vulnerabilities of a smart thermostat
Proceedings of 2016 14th Annual Conference on Privacy, Security and Trust (PST) in Auckland, New Zealand, 12-14 Dec. 2016. We address security vulnerabilities for a smart thermostat. As this kind of smart appliance is adopted in homes around the world, every user will be opening up a new avenue for cyber attack. Since these devices have known vulnerabilities and they are being managed by non-technical users, we anticipate that smart thermostats are likely to be targetted by unsophisticated attackers relying on publicly available exploits to take advantage of weakly protected devices. As such, in this paper, we take the role of a `script kiddy' and we assess the security of a smart thermostat by using Internet resources for attacks at both the physical level and the network level. We demonstrate that such attacks are unlikely to be effective without some additional social engineering to obtain user credentials. Moreover, we suggest that the vulnerability to attack can be further minimized by simply reducing the use of remote storage where possible., Conference paper
Exploring power storage profiles for vehicle to grid systems
Proceedings of the AAAI Workshop on Artificial Intelligence for Cities, Austin, USA, 2015. The Smart Grid allows users to monitor power usage through the use of Smart Meter technology. In principle, this information can be used to modify usage habits in a way that reduces consumer costs as well as greenhouse emissions. However, in an urban environment, many users are restricted by the same constaints: they work during the day, and they are home at night. This creates spikes in power cost at peak usage times, and it may also lead to increased emissions in scenarios where sustainable resources are limited. An individual user can avoid these spikes by using an electric car as a storage device; it can be charged at the cheapest times, and then discharged to the home at the most expensive times. While this idea is intuitively appealing, it turns out that the benefits vary greatly depending on the storage algorithm used. In this paper, we describe the Power Storage Simulator, a tool for experimenting with storage algorithms to improve the efficiency of vehicle to grid systems. We suggest that this tool is also useful for educating power consumers about load balancing on the Smart Grid through an engaging, visual simulation., Conference paper, Published.
Hygrothermal modeling of aerated concrete wall and comparison with field experiment
Proceedings of 3rd International Building Physics Conference: 27 August 2006, Montreal, QC. A two-dimensional heat, air and moisture transport model called hygIRC is adapted to simulate a well-documented field exposure of an aerated concrete wall section. Difficulties are encountered due to a few missing information on boundary conditions of the exposure and hygrothermal properties of aerated con-crete. The paper presents how these inadequacies were overcome to simulate the hygrothermal behavior of the wall section. Appropriate assumptions were made due to justifiable reasons. Then the model provides temporal and spatial distributions of temperature and relative humidity for an extended period that are in ex-cellent agreement with the documented field data. The paper presents the justifications for the assumptions and the comparison of experimental and simulation results., Conference paper, Published. A version of this document is published in: 3rd International Building Physics Conference, Montreal, QC., August 27, 2006, pp. 321-328.
Hygrothermal performance assessment of vented and ventilated wall systems
Proceedings of Thermal Performance of the Exterior Envelopes of Whole Buildings XII International Conference, At Clearwater Beach, Florida, USA, December 2013. Based on analysis of the drying and wetting potentials of a particular local climate, designers choose wall systems with or without an air gap between a sheathing membrane and a cladding layer. In addition to the capillary break that the air gap provides, thereby reducing the moisture transfer from wet cladding to the interior of the wall, the airspace will add the thermal resistance of the wall system and reduce the heat flow across the wall system. These moisture and thermal performances are straightforward to understand if the air in the air cavity is assumed to be a “still air.” In this paper, an experimental study is undertaken to under-stand the impact of airflow through an air cavity on the moisture and thermal performance of wall systems. To achieve this objective three test panels are instrumented and monitored in the field-experimental setting: one with no air gap, another one with an air gap but restricted airflow, and the third one with an air gap and open for airflow. The second and third wall systems have the same air gap width but different top flashing designs creating vented and ventilated wall systems. For the wall systems’ orientation and boundary conditions considered in this study, the wall with no air gap accumulates relatively high moisture content on the sheathing board, stud, and bottom plate and also has high moisture content changes in a year cycle when compared to the vented and ventilated wall systems. In general, the hygrothermal performances of vented and ventilated wall systems are comparable. During the winter period when relatively high moisture accumulation occurs, the upper section of the ventilated wall system shows slightly lower moisture content compared to that of the vented wall system. The temperature readings of the sheathing boards in the vented and ventilated wall systems are slightly warmer than that of the wall with no air gap for 85.5% and 73% of the time (based on hourly data of a year), respectively. For the balance of a period of time, the sheathing boards in the walls with an air cavity are slightly cooler than that of the wall with an air gap. Although the low temperature on the sheathing board, which is caused by solar radiation-induced airflow, is beneficial during a cooling season, the air gap and the associated airflow may reduce the heat gain that may be obtained from solar radiation during the heating season. The implications of air cavity and flashing design (airflow rate) on the heating and cooling load calculations of different orientations, wall configurations, and climate require further investigation., Conference paper, Published.
Hygrothermal performance of exterior wall systems using an innovative vapour retarder in Canadian climate
Proceeding of the 4th International Building Physics Conference: 15 June 2009, Istanbul, Turkey. This paper provides highlights of the research work carried out at the National Research Council Canada, Institute for Research in Construction on assessing the hygrothermal performance of wall systems that included this innovative vapour retarder (Note: Vapour Barrier in Canadian terminology is equivalent to Vapor retarder in US terminology). The performance of walls was assessed when subjected to eastern coastal climate conditions of Halifax, one of the four Canadian climatic locations used in this study. A wood-framed stucco clad wall was the reference assembly. Results from different cases based on the variation of vapour control strategies and their effect on the hygrothermal performance of the wall systems are analysed. The results for the Halifax climate location indicate that the installation of a humidity controlled, innovative vapour retarder is a recommendable solution for the envelope design of residential buildings of these locations with moderate or high water vapour permeance of the interior paint. In this study, the advanced hygrothermal tool, hygIRC, was used to perform the hygrothermal performance analysis of the wall systems., Peer reviewed article, Published. A version of this document is published in: 4th International Building Physics Conference, Istanbul, Turkey, June 15-18, 2009, pp. 1-8.
Hygrothermal performance of RH-dependent vapour retarder in Canadian coastal climate
Proceedings of 12th Canadian Conference of Building Science and Technology: 06 May 2009, Montreal, QC. The hygrothermal performance of wood-frame wall with stucco cladding exposed to the coastal climate of Vancouver, BC, is studied. The primary objective of the study is to compare the moisture management performance of two vapour barriers: the relatively new SmartVapour Retarder (SVR) and commonly used Polyethylene sheet. For a reference purpose a wood-frame wall with no vapour barrier is considered as well. The performances of these three walls, which are exposed to the same indoor and outdoor climatic loads, are compared with respect to their dynamic responses to two simulation variables: interior moisture load (simulated water intrusion in the stud cavity) and paint on the interior gypsum board. The water intrusion is assumed to be through defect areas and the quantity is correlated with the amount of wind-driven rain that the wall is exposed to. The hygrothermal simulation results suggest that adoption of SVR as a vapour barrier yields better moisture management of the sheathing board (OSB) for any conditions considered in this paper including internal moisture load and interior paint. But, in coastal climate, it may have adverse effect on the moisture management of the interior gypsum board, in cases where water leaks into the cavity and the interior gypsum board is painted with low-vapour permeance paint., Peer reviewed article, Published. A version of this document is published in: 12th Canadian Conference of Building Science and Technology, Montreal, QC, May 6-8, 2009, pp. 1-12
Hygrothermal performance of ventilated attic in marine climate under different ceiling air tightness
14th International Conference on Indoor Air Quality and Climate (Indoor Air 2016), July 3-8, 2016, Ghent, Belgium. An indoor to attic air leakage and vice-versa significantly affect indoor air, thermal comfort and the hygrothermal performance in both living space and unconditioned space. In cold and marine climates an air leakage from living space to an attic brings a relatively high relative humidity to the attic space. This effect is primarily responsible for condensation in attic structural parts such as roof sheathings. In this paper, the hygrothermal performance of a ventilated attic in wet costal climates under different ceiling air leakage is studied. A benchmarked whole building Heat-Air-Moisture model named HAMFit is used to study hygrothermal performance of ventilated attics in marine climates. The attic is modelled as 2-dimensional geometry with coupled heat transfer, moisture transport and a turbulence Computational Fluid Dynamics through attic space and porous structural parts of the attic. A vent ratio of 1/300 and three types normalized leakage area (tight, normal and leaky) are used to analyse how the moisture transport behaves in ventilated space. A winter weather data of city of Vancouver, BC is used to represent a wet marine climate. Our findings show specific locations in the attic structure are more exposed to moisture related problems and the air circulation and temperature distribution due to ventilation under multiple ceiling air leakage scenarios are presented. Hygrothermal performance of ventilated attic in marine climate under different ceiling air tightness., Conference paper, Published.
Hygrothermal properties of exterior claddings, sheathing boards, membranes and insulation materials for building envelope design
Proceedings of Thermal Performance of the Exterior Envelopes of Whole Buildings X International Conference: 02 December 2007, Clearwater, Florida. Testing was conducted to determine those construction material properties that affect the movement of heat, air, and moisture in building envelopes. The paper reports the density, thermal conductivity, equilibrium moisture content, water vapor permeability, water absorption coefficient, liquid diffusivity, and air permeability of twenty-three building materials commonly used in North American including: exterior claddings, exterior sheathing boards, membranes and insulations. The paper also discusses the experimental and analytical procedures used to determine these properties., Conference paper, Published. A version of this document is published in: Proceedings of Thermal Performance of the Exterior Envelopes of Whole Buildings X, Clearwater, Florida, Dec. 2-7, 2007, pp. 1-16.
Impact of V2G on real-time adaptive Volt/VAr optimization of distribution networks
Proceeding of IEEE ElectricalPower and Energy Conference (EPEC 2013), Aug. 2013, Halifax, Canada. Deployment of Smartgrid downstream features such as Smart Metering, pervasive control and Distributed Management Systems has brought great opportunities for distribution network planners to optimize the network in more precise methods. Moreover, the advent of Electric Vehicles (EVs) has brought more opportunities for grid optimization. Recent studies stipulate that EVs are able to inject reactive power into the grid by changing their inverter's operating mode. This paper primarily discusses a real-time adaptive Volt/VAr Optimization (VVO) engine, designed to minimize system apparent power losses, optimize voltage profiles, and reduce the operating costs of Switched Capacitor Banks of the grid. The paper goes on to study the impact of EVs on the distribution network VVO, taking into account different EV charging and penetration levels and checks the validity of the proposed algorithm by employing revised IEEE-37 Node Test Feeder in presence of various load types as a case study., Conference paper, Published.
Indoor humidity levels of houses in Pacific coastal climate
9th International Conference on Indoor Air Quality, Ventilation & Energy Conservation (IAQVEC), October 23-26, 2016, Songdo, South Korea. This project studied the relative humidity and indoor temperature variations in three houses in the pacific coastal climates. The houses have been monitored for one month in each four different seasons under different size of occupants, temperature variation and living conditions. These three houses represent different air tightness, number of occupants and floor size. The temperature and RH data loggers are used in every room in each house to better understand which rooms in a certain living conditions are more susceptible to moisture related problems. In addition, three existing models (European Indoor Class Model, ASHRAE 160P simple and intermediate models) are used to generate the indoor humidity level and the calculated values are compared to the measured field data., Conference paper, Published.
Initial evaluation of the FreeWheel™ wheelchair attachment
Proceedings of Rehabilitation Engineering and Assistive Technology Society of North America Annual Conference 2011. The FreeWheel™ wheelchair attachment was developed to overcome the burden that front casters pose to manual wheelchairs., Conference paper, Published.
Iterated belief change
Proceedings of the International Joint Conference on Artificial Intelligence (IJCAI-05) in Edinburgh, Scotland, 2005. We use a transition system approach to reason about the evolution of an agent’s beliefs as actions are executed. Some actions cause an agent to perform belief revision and some actions cause an agent to perform belief update, but the interaction between revision and update can be nonelementary. We present a set of basic postulates describing the interaction of revision and update, and we introduce a new belief evolution operator that gives a plausible interpretation to alternating sequences of revisions and updates., Conference paper, Published.
Life-cycle performance framework for building sustainability
Proceedings from the International High Performance Buildings Conference 2010. In spite of the progress in the development of methods and tools to support sustainable building design, there is still a lack of a formal method to bridge the “no man’s land” gap between the traditional building engineering disciplines, and between these and the architecture, to achieve the level of building integration required for sustainability. The framework described in this paper is an attempt to develop such a method. The framework, grounded on building science, facilitates a comprehensive assessment of the life-cycle performance of buildings and building systems, by enabling multiple function-performance factors of a building to be addressed iteratively. Quantitative methods and test protocols can be incorporated into the framework for assessing the long-term viability of proposed solutions. The organization of the underlying principles of building life-cycle performance described in this paper will hopefully conduct to a more integrated treatment of buildings in research, education, and practice., Peer reviewed, Conference proceeding, Published.

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