In northern coastal climates, surface condensation often occurs in fenestration systems during winter. The most common contributors of this phenomenon are air leakage, thermal bridging, local convection and radiation. (i.e. boundary conditions). Researchers and industry experts typically focus on improving designs of fenestration and developing different strategies to deal with air leakage and thermal bridging. However, the effects of local convection and radiation on window condensation are often overlooked. This project focuses on investigating the ways different heating systems internet with window-wall systems via convection and radiation heat exchanges, and their effects on surface condensation. The three most common heating systems for multi-unit residential building (MURB) arc considered: electric baseboard, hydronic radiant floor and forced air system. Each heating system provides vastly different indoor conditions due to differences in thermal stratification, room air distribution and location of heat sources. These differences have direct impacts on window performance and potentially increase risk of condensation. In this project, the following questions are investigated: How significant is impact of room air flow on condensation risk in window-wall systems? Are empirical film coefficients sufficient for predicting condensation risk of window-wall units' What are the differences between each of the heating systems on condensation risk? This project designed a methodology in an attempt to better understand and predict these physical phenomena and will hopefully guide further efforts to better characterize the effect of different heating systems in window condensation risk analysis., Peer reviewed, Peer reviewed article, Published.
Curcuma longa L. rhizomes are used extensively as a spice in food preparations and dietary supplements for their anti-inflammatory and antioxidant properties. An expert review panel (ERP) evaluated analytical methods for the quantitation of individual curcuminoids for the purpose of identifying a method for official method status. It was requested that several modifications be undertaken to improve method performance prior to subjecting the chosen method to a single-laboratory validation. Two separate Plackett-Burman factorial studies were used to identify factors that contributed to the chromatographic separation and extraction of curcuminoids. Significant factors were further optimized to produce the improved HPLC method for curcuminoid separation. This method was then subjected to a single-laboratory validation according to the AOAC International guidelines for linearity, detection limits, precision, and accuracy. The two most significant factors impacting the quantitation of curcuminoids were column temperature and extraction solvent, which were optimized to 55 °C and 100 % methanol, respectively. The validation was performed on 12 raw materials and finished products containing turmeric roots. The method precision was reported using HorRat values which were within recommended ranges of the AOAC guidelines. Overall accuracy of the method was accessed at three separate levels for each analyte and ranged from 99.3–100.9 %. The validated method is suitable for quantitation of individual curcuminoids in turmeric raw materials and finished products and is recommended for consideration as an official method by the AOAC International., Peer-reviewed article, Published. Received 13 July 2015; Accepted 21 September 2015; Published online 29 September 2015.
The demand for validated analytical methods for botanicals has grown in response to the increasing consumer market for botanical supplements. Government initiatives to increase the availability of validated analytical methods and botanical reference material have led to the publication of numerous validation studies in scientific journals. Single laboratory validation and collaborative validation studies are structured to confirm a method's ruggedness and fit for purpose. The performance characteristics and statistical protocols followed throughout a validation study vary with the source of guidelines. Analytical techniques and priority methods are influenced by the need for fast-screening techniques, the limited availability of reference material, market value, and the prevalence of contaminants in botanical supplements., Peer-reviewed article, Published.
The Neil Squire Foundation (NSF) is a Canadian nonprofit organization whose purpose is to create opportunities for independence for individuals who have significant physical disabilities. Over the last ten years, our team in partnership with researchers at the Electrical and Computer Engineering Department, the University of British Columbia, has been working to develop a direct brain-controlled switch for individuals with significant physical disabilities. The NSF Brain Interface Project primarily focuses on the development of brain-computer interface switch technologies for intermittent (or asynchronous) control in natural environments. That is, technologies that will work when the user intends control but also remains in a stable off state when there is no intent to control. A prototype of such a switch has successfully been developed. This switch has demonstrated classification accuracies greater than 94%. The initial results are promising, but further research is required to improve switch accuracies and reliability and to test these switch technologies over a larger population of users and operating conditions. This paper provides an overview of the NSF brain-switch technologies and details our approach to future work in this area., Peer-reviewed article, Published. Manuscript received June 20, 2002; revised January 22, 2003.
This chapter discusses anomalies which may not be attributed to expected operational deviations and/or mishaps associated with component failure and/or environmental conditions. The question here is: what are known cyber-security vulnerabilities which could be used to aid in the detection of patterns and signatures associated with various types of attacks and intrusions in the system which need to be detected and analyzed using Smart Grid's sensory data, such as Smart meter's and/or PMU's data, to help differentiate between "cyber-attacks in progress" as opposed to "expected system anomalies" due to operational failures of its components?, book chapter, published
Axonal plasticity in the adult spinal cord is governed by intrinsic neuronal growth potential and by extracellular cues. The p75 receptor (p75(NTR)) binds growth-promoting neurotrophins (NTs) as well as the common receptor for growth-inhibiting myelin-derived proteins (the Nogo receptor) and so is well situated to gauge the balance of positive and negative influences on axonal plasticity. Using transgenic mice lacking the extracellular NT-binding domain of p75(NTR) (p75-/- mice), we have examined the influence of p75(NTR) on changes in the density of primary afferent (calcitonin gene-related peptide-expressing) and descending monoaminergic (serotonin- and tyrosine hydroxylase-expressing) projections to the dorsal horn after dorsal rhizotomy, with and without concomitant application of exogenous nerve growth factor and NT-3. We found that, in intact p75-/- mice, the axon density of all populations was equal to or less than that in wild-type mice but that rhizotomy-induced intraspinal sprouting was significantly augmented. Monoaminergic axon sprouting was enhanced in both nerve growth factor- and NT-3-treated p75-/- mice compared with similarly treated wild-type mice. Primary afferent sprouting was particularly robust in NT-3-treated p75-/- mice. These in vivo results illustrate the interactions of p75(NTR) with NTs, with their respective tropomyosin-related kinase receptors and with inhibitory myelin-derived molecules. Our findings illustrate the pivotal role of p75(NTR) in spinal axonal plasticity and identify it as a potential therapeutic target for spinal cord injury., Peer-reviewed article, Published. Received 14 August 2004; Revised 7 October 2004; Accepted 25 October 2004.
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.
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
A new approach to design a dynamic model of genes with multiple autonomous regulatory modules by evolutionary computations is proposed. The approach is based on Genetic Algorithms (GA), with new crossover operators especially designed for these purposes. The new operators use local homology between parental strings to preserve building blocks found by the algorithm. The approach exploits the subbasin-portal architecture of the fitness functions suitable for this kind of evolutionary modeling. This architecture is significant for Royal Road class fitness functions. Two real-life Systems Biology problems with such fitness functions are implemented here: evolution of the bacterial promoter rrnP1 and of the enhancer of the Drosophila even-skipped gene. The effectiveness of the approach compared to standard GA is demonstrated on several benchmark and reallife tasks., Peer-reviewed article, Published.
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
One avenue of research for partial restoration of function following spinal cord injury is the use of neural prostheses, an example of which is functional electrical stimulation (FES) devices for motor functions. Neural prostheses may also be useful for the extraction of sensory information directly from the nervous system. We suggest the spinal cord as a possible site for the detection of peripheral sensory information from neural activity alone. Acute multichannel extracellular recordings were used to extract neural spike activity elicited from peripheral sensations from the spinal cords of rats. To test the recording method and classification potential, eight classes of sensory events were recorded consisting of electrical stimulation of seven locations on rat forepaws, and another class of data during which no stimulus was present. A dual-stage classification scheme using principal component analysis and k-Means clustering was devised to classify the sensory events during single trials. The eight tasks were correctly identified at a mean accuracy of 96%. Thus, we have shown the methodology to detect and classify peripheral sensory information from multichannel recordings of the spinal cord. These methods may be useful, for example, in a closed-loop FES for restoration of hand grasp., Peer-reviewed article, Published. Manuscript received October 24, 2005; revised February 25, 2006.
A single-laboratory validation (SLV) was conducted on an HPLC method for the detection and quantification of aloin A and aloin B in Aloe vera raw materials and finished products. An extraction procedure using sonication with an acidified solvent was used for solid test materials while liquid test materials only required dilution, if necessary, prior to filtration and analysis. Separation was achieved using a fused core C18 column in 18 min under isocratic elution conditions allowing for a single analyte (aloin A) calibration curve to quantify both aloins. Adequate chromatographic resolution (Rs ≥ 1) was achieved for aloin A and aloin B. The calibration curves for aloin A exhibited coefficients of determination (r(2)) of ≥ 99.9% over the linear range of 0.3-50 μg/mL. The LOD values were 0.092 and 0.087 μg/mL, and LOQ 0.23 and 0.21 μg/mL for aloin A and aloin B, respectively. Repeatability studies were performed on nine test materials on each of 3 separate days, with five of the test materials determined to be above the LOQ having repeatability RSD (RSDr) values ranging from 0.61 to 6.30%. Method accuracy was determined through a spike recovery study on both liquid and solid matrixes at three different levels: low, medium, and high. For both aloins, the recovery in the liquid matrix ranged from 92.7 to 106.3% with an RSDr of 0.15 to 4.30%, while for the solid matrix, the recovery ranged from 84.4 to 108.9% with an RSDr of 0.23 to 3.84%. Based on the results of the SLV study, it is recommended that this method be evaluated for reproducibility through a collaborative study., Peer-reviewed article, Published. Received January 27, 2013; Accepted by AP April 10, 2014.