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- Resource Type:
- Article
- Creator:
- Rubtsov, Alexander M., Petukhov, Sergei P., Murtazina, Dilyara A., Lopina, Olga D., and Storey, Kenneth B.
- Abstract:
- A 100-kDa protein that is a main component of the microsomal fraction from rabbit gastric mucosa is phosphorylated by cAMP-dependent protein kinase (PKA) in the presence of 0.2% Triton X-100. Microsomes from rabbit gastric mucosa possess activity of H,K-ATPase but not activity of Na,K-ATPase. Incubation of microsomes with 5 μM fluorescein 5′-isothiocyanate (FITC) results in both an inhibition of H,K-ATPase and labeling of a protein with an electrophoretic mobility corresponding to the mobility of the protein phosphorylated by PKA. The data suggest that the α-subunit of H,K-ATPase can be a potential target for PKA phosphorylation.
- Date Created:
- 1999-07-27
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- Resource Type:
- Article
- Creator:
- Anisman, Hymie, Audet, Marie-Claude, McQuaid, Robyn J., and Jacobson-Pick, Shlomit
- Abstract:
- Social defeat in mice is a potent stressor that promotes the development of depressive- and anxiety-like behaviours, as well as variations of neuroendocrine and brain neurotransmitter activity. Although environmental enrichment may protect against some of the adverse behavioural and biological effects of social defeat, it seems that, among male group-housed mice maintained in an enriched environment (EE), aggressive behaviours may be more readily instigated, thus promoting distress and exacerbating psychopathological features. Thus, although an EE can potentially have numerous beneficial effects, these may depend on the general conditions in which mice were raised. It was observed in the current investigations that EE group-housed BALB/cByJ mice displayed increased anxiety-like behaviours compared to their counterparts maintained in a standard environment (SE). Furthermore, in response to social defeat, EE group-housed male mice exhibited decreased weight gain, exaggerated corticosterone elevations and altered hippocampal norepinephrine utilization compared to their SE counterparts. These effects were not apparent in the individually housed EE mice and, in fact, enrichment among these mice appeared to buffer against serotonin changes induced by social defeat. It is possible that some potentially beneficial effects of enrichment were precluded among group-housed mice, possibly owing to social disturbances that might occur in these conditions. In fact, even if social interaction is an essential feature of enrichment, it seems that some of the positive effects of this housing condition might be optimal when mice are housed individually, particularly with regard to buffering the effects of social defeat.
- Date Created:
- 2013-03-01
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- Resource Type:
- Article
- Creator:
- Bialiayeu, A., Ianoul, Anatoli, Prezgot, Dan, Bottomley, Adam, and Albert, Jacques
- Abstract:
- A novel technique for increasing the sensitivity of tilted fibre Bragg grating (TFBG) based refractometers is presented. The TFBG sensor was coated with chemically synthesized silver nanowires 100nm in diameter and several micrometres in length. A 3.5-fold increase in sensor sensitivity was obtained relative to the uncoated TFBG sensor. This increase is associated with the excitation of surface plasmons by orthogonally polarized fibre cladding modes at wavelengths near 1.5μm. Refractometric information is extracted from the sensor via the strong polarization dependence of the grating resonances using a Jones matrix analysis of the transmission spectrum of the fibre.
- Date Created:
- 2012-11-09
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- Resource Type:
- Article
- Creator:
- Lesparre, Nolwenn, Adler, Andy, Komorowski, Jean-Christophe, Grychtol, Bartłomiej, and Gibert, Dominique
- Abstract:
- The electrical resistivity distribution at the base of La Soufrière of Guadeloupe lava dome is reconstructed by using transmission electrical resistivity data obtained by injecting an electrical current between two electrodes located on opposite sides of the volcano. Several pairs of injection electrodes are used in order to constitute a data set spanning the whole range of azimuths, and the electrical potential is measured along a cable covering an angular sector of ≈120? along the basis of the dome. The data are inverted to performa slice electrical resistivity tomography (SERT) with specific functions implemented in the EIDORS open source package dedicated to electrical impedance tomography applied to medicine and geophysics. The resulting image shows the presence of highly conductive regions separated by resistive ridges. The conductive regions correspond to unconsolidated material saturated by hydrothermal fluids. Two of them are associated with partial flank collapses and may represent large reservoirs that could have played an important role during past eruptive events. The resistive ridges may represent massive andesite and are expected to constitute hydraulic barriers.
- Date Created:
- 2014-01-01
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- Resource Type:
- Article
- Creator:
- Albert, Jacques and Chen, Chengkun
- Date Created:
- 2006-09-05
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Non-uniform-tilt-modulated fiber Bragg grating for temperature-immune micro-displacement measurement
- Resource Type:
- Article
- Creator:
- Chen, Chengkun, Guo, Tuan, and Albert, Jacques
- Date Created:
- 2009-04-10
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- Resource Type:
- Article
- Creator:
- Hibino, Y., Kitagawa, T., Hill, K. O., Bilodeau, F., Jihnson, D. C., Malo, B., Theriault, S., Albert, Jacques, and Hattori, K.
- Abstract:
- Single-longitudinal-mode operation of Er3+-P2O5-codoped silica planar waveguide lasers which are equipped with integrated Bragg grating reflectors is demonstrated, with a polarized output of 340 μW at 1546 nm. The gratings are photo-imprinted using 193 nm light exposure through a phase mask in GeO2-free optical waveguides that have been sensitized by H2 loading.
- Date Created:
- 1994-08-04
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- Resource Type:
- Article
- Creator:
- Hill, K. O., Albert, Jacques, Bilodeau, F., Johnson, D. C., Malo, B., and Theriault, S.
- Abstract:
- The core refractive index of Corning SMF-28 optical fibre exposed to ArF laser pulses increases with the square of the fluence per pulse. Bragg gratings with a refractive index modulation amplitude higher than 10 -3 have been obtained. This is an order of magnitude improvement over previously reported values for this type of fibre in the absence of treatment to enhance the photosensitivity.
- Date Created:
- 1995-05-25
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- Resource Type:
- Article
- Creator:
- Johnson, D. C., Malo, B., Albert, Jacques, Bilodeau, F., and Hill, K. O.
- Abstract:
- When hydrogen loading is used to enhance the photosensitivity of silica-based optical waveguides and fibres, the presence of molecular hydrogen dissolved in the glass matrix changes the effective index of propagation of guided optical modes by as much as 0.05%. Real-time monitoring of the reflectivity spectrum of Bragg gratings written in such conditions shows that the centre wavelength follows the changes in hydrogen concentration due to diffusion and reaction with glass defects.
- Date Created:
- 1994-01-01
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- Resource Type:
- Article
- Creator:
- Takiguchi, K., Johnson, D. C., Hill, K. O., Hagimoto, K., Kitagawa, T., Malo, B., Bilodeau, F., Theriault, S., Albert, Jacques, and Kataoka, T.
- Abstract:
- An apodized chirped in-fibre Bragg grating that has a linear dispersion characteristic is reported. The frequency components of an optical pulse (centre wavelength 1551 nm; 10 GHz bandwidth) incident on the grating are reflected with a relative delay that varies linearly from 0 to 130 ps across the spectral width of the pulse. The dispersion compensator is used to correct for the dispersion in a 100 km link (nondispersion shifted fibre) operating at a 10 Gbit/s transmission rate and a wavelength of 1551 nm.
- Date Created:
- 1994-10-13
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- Resource Type:
- Article
- Creator:
- Johnson, D. C., Theriault, S., Malo, B., Bilodeau, F., Hill, K. O., and Albert, Jacques
- Abstract:
- An apodized in-fibre Bragg grating reflector is fabricated using the phase mask photoimprinting technique. The reflector has a centre wavelength of 1550 nm, a bandwidth of 0.22 nm and a peak reflectivity of 90%. At 0.4 nm (50 GHz) from the centre wavelength the reflectivity is 40 dB lower than the peak reflectivity; this is an improvement of more than 20 dB over an unapodized Bragg grating reflector with similar bandwidth and peak reflectivity.
- Date Created:
- 1995-02-02
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- Resource Type:
- Article
- Creator:
- Banks, Sarah N., Millard, Koreen, Behnamian, Amir, White, Lori, Richardson, Murray, and Pasher, Jon
- Abstract:
- Random Forests variable importance measures are often used to rank variables by their relevance to a classification problem and subsequently reduce the number of model inputs in high-dimensional data sets, thus increasing computational efficiency. However, as a result of the way that training data and predictor variables are randomly selected for use in constructing each tree and splitting each node, it is also well known that if too few trees are generated, variable importance rankings tend to differ between model runs. In this letter, we characterize the effect of the number of trees (ntree) and class separability on the stability of variable importance rankings and develop a systematic approach to define the number of model runs and/or trees required to achieve stability in variable importance measures. Results demonstrate that both a large ntree for a single model run, or averaged values across multiple model runs with fewer trees, are sufficient for achieving stable mean importance values. While the latter is far more computationally efficient, both the methods tend to lead to the same ranking of variables. Moreover, the optimal number of model runs differs depending on the separability of classes. Recommendations are made to users regarding how to determine the number of model runs and/or trees that are required to achieve stable variable importance rankings.
- Date Created:
- 2017-09-15
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- Resource Type:
- Article
- Creator:
- Cross, Emma, Smith, Robert, and Mould, David
- Abstract:
- The rise of game development and game studies on university campuses prompts academic libraries to consider how to support teaching and research in this area. This article examines current issues and challenges in the development of game collections at academic libraries. The gaming ecosystem has become more complex and libraries may need to move beyond collections largely based on console video games. This article will advance the discussion by considering emerging issues to support access to the full range of games. The article will use examples from Carleton University Library, Ottawa, which has been developing a game collection since 2008.
- Date Created:
- 2015-01-01
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- Resource Type:
- Article
- Creator:
- Ballamingie, Patricia and Tudin, Susan
- Date Created:
- 2013-05-01
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- Resource Type:
- Article
- Creator:
- Riva, Pat, Cross, Emma, Andrews, Sue, Oliver, Chris, and Grover, Trina
- Abstract:
- This article describes the progress made toward implementing Resource Description and Access (RDA) in libraries across Canada, as of Fall 2013. Differences in the training experiences in the English-speaking cataloging communities and French-speaking cataloging communities are discussed. Preliminary results of a survey of implementation in English-Canadian libraries are included as well as a summary of the support provided for French-Canadian libraries. Data analysis includes an examination of the rate of adoption in Canada by region and by sector. Challenges in RDA training delivery in a Canadian context are identified, as well as opportunities for improvement and expansion of RDA training in the future.
- Date Created:
- 2014-01-01
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- Resource Type:
- Article
- Creator:
- Beausoleil-Morrison, Ian, Wills, A. D., and Ugursal, V. I.
- Abstract:
- The design and analysis of community-scale energy systems and incentives is a non-trivial task. The challenge of such undertakings is the well-documented uncertainty of building occupant behaviours. This is especially true in the residential sector, where occupants are given more freedom of activity compared to work environments. Further complicating matters is the dearth of available measured data. Building performance simulation tools are one approach to community energy analysis, however such tools often lack realistic models for occupant-driven demands, such as appliance and lighting (AL) loads. For community-scale analysis, such AL models must also be able to capture the temporal and inter-dwelling variation to achieve realistic estimates of aggregate electrical demand. This work adapts the existing Centre for Renewable Energy Systems Technology (CREST) residential energy model to simulate Canadian residential AL demands. The focus of the analysis is to determine if the daily, seasonal, and inter-dwelling variation of AL demands estimated by the CREST model is realistic. An in-sample validation is conducted on the model using 22 high-resolution measured AL demand profiles from dwellings located in Ottawa, Canada. The adapted CREST model is shown to broadly capture the variation of AL demand variations observed in the measured data, however seasonal variation in daily AL demand behaviour was found to be under-estimated by the model. The average and variance of daily load factors was found to be similar between measured and modelled. The model was found to under-predict the daily coincidence factors of aggregated demands, although the variance of coincident factors was shown to be similar between measured and modelled. A stochastic baseload input developed for this work was found to improve estimates of the magnitude and variation of both baseload and peak demands.
- Date Created:
- 2017-09-05
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- Resource Type:
- Article
- Creator:
- Hayes, M.J.D., Jung, B., Langlois, Robert, and Copeland, Z.
- Date Created:
- 2016-01-01
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- Resource Type:
- Conference Proceeding
- Creator:
- Whitehead, Anthony D.
- Abstract:
- we present a method of segmenting video to detect cuts with accuracy equal to or better than both histogram and other feature based methods. As well, the method is faster than other feature based methods. By utilizing feature tracking on corners, rather than lines, we are able to reliably detect features such as cuts, fades and salient frames. Experimental evidence shows that the method is able to withstand high motion situations better than existing methods. Initial implementations using full sized video frames are able to achieve processing rates of 10-30 frames per second depending on the level of motion and number of features being tracked; this includes the time to generate the MPEG decompressed frames.
- Date Created:
- 2003-01-01
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- Resource Type:
- Conference Proceeding
- Creator:
- Nayak, Amiya, Du, Jingzhe, and Kranakis, Evangelos
- Abstract:
- We describe a novel Distributed Storage protocol in Disruption (Delay) Tolerant Networks (DTN). Since DTNs can not guarantee the connectivity of the network all the time, distributed data storage and look up has to be performed in a store-and-forward way. In this work, we define local distributed location regions which are called cells to facilitate the data storage and look up process. Nodes in a cell have high probability of moving within their cells. Our protocol resorts to storing data items in cells which have hierarchical structure to reduce routing information storage at nodes. Multiple copies of a data item may be stored at nodes to counter the adverse impact of the nature of DTNs. The cells are relatively stable regions and as a result, data exchange overheads among nodes are reduced. Through experimentation, we show that the proposed distributed storage protocol achieves higher successful data storage ratios with lower delays and limited data item exchange requirements than other protocols in the literature.
- Date Created:
- 2010-08-27
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- Resource Type:
- Conference Proceeding
- Creator:
- Yanikomeroglu, Halim and Al-Ahmadi, Saad
- Date Created:
- 2009-10-19
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- Resource Type:
- Article
- Creator:
- Mac Neil, Michael
- Date Created:
- 2014-01-01
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- Resource Type:
- Article
- Creator:
- Guigue, Alexis and Hayes, M. John
- Abstract:
- It has been observed in the literature that as the cardinality of the prescribed discrete input-output data set increases, the corresponding four-bar linkages that minimise the Euclidean norm of the design and structural errors tend to converge to the same linkage. The important implication is that minimising the Euclidean norm, or any p-norm, of the structural error, which leads to a nonlinear least-squares problem requiring iterative solutions, can be accomplished implicitly by minimising that of the design error, which leads to a linear least-squares problem that can be solved directly. Apropos, the goal of this paper is to take the first step towards proving that as the cardinality of the data set tends towards infinity the observation is indeed true. In this paper we will integrate the synthesis equations in the range between minimum and maximum input values, thereby reposing the discrete approximate synthesis problem as a continuous one. Moreover, we will prove that a lower bound of the Euclidean norm, and indeed of any p-norm, of the design error for planar RRRR function-generating linkages exists and is attained with continuous approximate synthesis.
- Date Created:
- 2016-07-01
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- Resource Type:
- Article
- Creator:
- Bucking, Scott, Zmeureanu, Radu, and Athienitis, Andreas
- Abstract:
- Building Performance Simulation (BPS) is a powerful tool to estimate and reduce building energy consumption at the design stage. However, the true potential of BPS remains unrealized if trial and error simulation methods are practiced to identify combinations of parameters to reduce energy use of design alternatives. Optimization algorithms coupled with BPS is a process-orientated tool which identifies optimal building configurations using conflicting performance indicators. However, the application of optimization approaches to building design is not common practice due to time and computation requirements. This paper proposes a hybrid evolutionary algorithm which uses information gained during previous simulations to expedite and improve algorithm convergence using targeted deterministic searches. This technique is applied to a net-zero energy home case study to optimize trade-offs in passive solar gains and active solar generation using a cost constraint.
- Date Created:
- 2013-08-27
-
- Resource Type:
- Article
- Creator:
- Sénéchal, Monique and Lever, Rosemary
- Abstract:
- Oral narrative skills are assumed to develop through parent-child interactive routines. One such routine is shared reading. A causal link between shared reading and narrative knowledge, however, has not been clearly established. The present research tested whether an 8-week shared-reading intervention enhanced the fictional narrative skills of children entering formal education. Dialogic reading, a shared reading activity that involves elaborative questioning techniques, was used to engage children in oral interaction during reading and to emphasize elements of story knowledge. Forty English-speaking five- and six-year-olds were assigned to either the dialogic-reading or an alternative-treatment group. ANCOVA results found that the dialogic-reading children’s post-test narratives were significantly better on structure and context measures than those for the alternative-treatment children, but results differed for produced or retold narratives. The dialogic-reading children also showed expressive vocabulary gains. Overall, this study concretely determined that aspects of fictional narrative construction knowledge can be learned from interactive book reading.
- Date Created:
- 2011-01-01
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- Resource Type:
- Article
- Creator:
- Ugursal, V. Ismet, Beausoleil-Morrison, Ian, Nikoofard, Sara, and Asaee, S. Rasoul
- Abstract:
- Techno-economic impact of retrofitting houses in the Canadian housing stock with PV and BIPV/T systems is evaluated using the Canadian Hybrid End-use Energy and Emission Model. Houses with south, south-east and south-west facing roofs are considered eligible for the retrofit since solar irradiation is maximum on south facing surfaces in the northern hemisphere. The PV system is used to produce electricity and supply the electrical demand of the house, with the excess electricity sold to the grid in a net-metering arrangement. The BIPV/T system produces electricity as well as thermal energy to supply the electrical as well as the thermal demands for space and domestic hot water heating. The PV system consists of PV panels installed on the available roof surface while the BIPV/T system adds a heat pump, thermal storage tank, auxiliary heater, domestic hot water heating equipment and hydronic heat delivery system, and replaces the existing heating system in eligible houses. The study predicts the energy savings, GHG emission reductions and tolerable capital costs for regions across Canada. Results indicate that the PV system retrofit yields 3% energy savings and 5% GHG emission reduction, while the BIPV/T system yields 18% energy savings and 17% GHG emission reduction in the Canadian housing stock. While the annual electricity use slightly increases, the fossil fuel use of the eligible houses substantially decreases due to BIPV/T system retrofit.
- Date Created:
- 2017-10-01
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- Resource Type:
- Article
- Creator:
- Johnson, Geoffrey, Beausoleil-Morrison, Ian, and Wills, Adam
- Abstract:
- Fuel cells with nominal outputs of approximately 1kW AC are emerging as a prime-mover of a micro-cogeneration system potentially well-suited to compete, on an energy basis, with conventional methods for satisfying occupant electrical and thermal demands in a residential application. As the energy benefits of these systems can be incremental when compared to efficient conventional methods, it is especially important to consider the uncertainties of the models on which simulation results are based. However, researchers have yet to take this aspect into account.This article makes a contribution by demonstrating how these model uncertainties may be propagated to the simulation results of a micro-cogeneration system for comparison to a reference scenario using a case study. This case study compares the energy performance of a fuel-cell based micro-cogeneration system serving only domestic hot water demands to an efficient reference scenario where the conventional methods for providing electrical and thermal demands are considered to be a central gas-fired combined-cycle plant and a condensing tankless water heater respectively. The simulation results demonstrated that if model uncertainties were ignored, it would have been possible to demonstrate that the considered micro-cogeneration system was more efficient than the reference scenario for average consumption levels of domestic hot water. However, when model uncertainties were considered, the efficiency of the considered micro-cogeneration system could not reliably exceed that of the reference scenario by serving the domestic hot water needs of a single-family home.
- Date Created:
- 2017-03-05
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- Resource Type:
- Article
- Creator:
- Beausoleil-Morrison, Ian and Johnson, Geoffrey
- Abstract:
- An improved understanding of the consumption patterns, end-uses, and temporal variations of electrical loads in houses is warranted because a significant fraction of a society's total electricity consumption occurs within residential buildings. In general, there is a lack of high-temporal-resolution data describing occupant electrical consumption that are available to researchers in this field. To address this, new measurements were performed and combined with data emanating from an earlier study to provide a database of annual measurements for 23 houses at a 1-min resolution that characterizes whole-house, non-HVAC, air conditioner, and furnace fan electrical draws, as well as the draw patterns of some major appliances. All houses were located in Ottawa, Canada. The non-HVAC measurements of this 23-house sample were shown to be in agreement with published estimates for the housing stock. The furnace fan was found to be the most significant end-use. These high-temporal-resolution data of electrical demands in houses can be used by researchers to increase the fidelity of building performance simulation analyses of different micro-generation technologies in residential buildings.
- Date Created:
- 2017-03-05
-
- Resource Type:
- Article
- Creator:
- Beausoleil-Morrison, Ian, Asaee, S. Rasoul, and Ugursal, V. Ismet
- Abstract:
- This study was conducted to assess the techno-economic feasibility of converting the Canadian housing stock (CHS) into net/near zero energy buildings by introducing and integrating high efficient and renewable/alternative energy technologies in new construction and existing houses. Performance assessment of energy retrofit and renewable/alternative energy technologies in existing houses in regional and national scale is necessary to devise feasible strategies and incentive measures. The Canadian Hybrid Residential End-Use Energy and GHG Emissions model (CHREM) that utilizes a bottom-up modeling approach is used to investigate the techno-economic feasibility of air to water heat pump retrofit in the Canadian housing stock. The proposed energy retrofit includes an air to water heat pump, auxiliary boiler, thermal storage tank, hydronic heat delivery and domestic hot water (DHW) heating. Energy savings, GHG emission changes and economic feasibility of the air source heat pump retrofit are considered in this study. Results show that there is a potential to reduce 36% of energy consumption and 23% of GHG emissions of the CHS if all eligible houses undertake the retrofit. Economic analysis indicates that the feasibility of air to water heat pump systems is strongly affected by the current status of primary energy use for electricity generation and space and DHW heating as well as energy prices and economic conditions. Legislation, economic incentives and education for homeowners are necessary to enhance the penetration level of air to water heat pump retrofits in the CHS.
- Date Created:
- 2017-01-25
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- Resource Type:
- Article
- Creator:
- Bucking, Scott and Dermardiros, Vasken
- Abstract:
- Buildings play a significant role in climate change mitigation. In North America, energy used to construct and operate buildings accounts for some 40% of total energy use, largely originating from fossil fuels. The strategic reduction of these energy demands requires knowledge of potential upgrades prior to a building's construction. Furthermore, renewable energy generation integrated into buildings façades and district systems can improve the resiliency of community infrastructure. However, loads that are non-coincidental with on-site generation can cause load balancing issues. This imbalance is typically due to solar resources peaking at noon, whereas building loads typically peak in the morning and late afternoon or evenings. Ideally, the combination of on-site generation and localized storage could remedy such load balancing issues while reducing the need for fossil fuels. In response to these issues, this paper contributes a methodology that co-optimizes building designs and district technologies as an integrated community energy system. A distributed evolutionary algorithm is proposed that can navigate over 10154 potential community permutations. This is the first time in literature that a methodology demonstrates the co-optimization of buildings and district energy systems to reduce energy use in buildings and balance loads at this scale. The proposed solution is reproducible and scalable for future community masterplanning studies.
- Date Created:
- 2018-02-01
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Techno-economic assessment of solar assisted heat pump system retrofit in the Canadian housing stock
- Resource Type:
- Article
- Creator:
- Beausoleil-Morrison, Ian, Asaee, S. Rasoul, and Ugursal, V. Ismet
- Abstract:
- The techno-economic feasibility of retrofitting existing Canadian houses with solar assisted heat pump (SAHP) is investigated. The SAHP architecture is adopted from previous studies conducted for the Canadian climate. The system utilizes two thermal storage tanks to store excess solar energy for use later in the day. The control strategy is defined in order to prioritise the use of solar energy for space and domestic hot water heating purposes. Due to economic and technical constraints a series of eligibility criteria are introduced for a house to qualify for the retrofit. A model was built in ESP-r and the retrofit was introduced into all eligible houses in the Canadian Hybrid Residential End-Use Energy and GHG Emissions model. Simulations were conducted for an entire year to estimate the annual energy savings, and GHG emission reductions. Results show that the SAHP system performance is strongly affected by climatic conditions, auxiliary energy sources and fuel mixture for electricity generation. Energy consumption and GHG emission of the Canadian housing stock can be reduced by about 20% if all eligible houses receive the SAHP system retrofit. Economic analysis indicates that the incentive measures will likely be necessary to promote the SAHP system in the Canadian residential market.
- Date Created:
- 2017-01-01
-
- Resource Type:
- Article
- Creator:
- Saurette, Marc
- Date Created:
- 2010-02-02
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- Resource Type:
- Article
- Creator:
- MacIsaac, Gregory
- Abstract:
- I examine the relation between sensation and discursive thought (dianoia) in Plato, Plotinus, and Proclus. In Theaetetus, a soul whose highest faculty was sensation would have no unified experience of the sensible world, lacking universal ideas to give order to the sensible flux. It is implied that such universals are grasped by the soul's thinking. In Plotinus the soul is not passive when it senses the world, but as the logos of all things it thinks the world through its own forms. Proclus argues against the derivation of universal logoi from the senses, which alone can't make the sensible world comprehensible. At most they give a record of the original sense-impression in its particularity. The soul's own projected logoi give the sensible world stability. For Proclus, bare sensation does not depend on thought, but a unified experience of the sense-world depends on its paradigmatic logoi in our souls.
- Date Created:
- 2014-01-01
-
- Resource Type:
- Article
- Creator:
- Vandusen, R., Tarr, Gary, Waldron, P. D., Celo, Dritan, Smy, Tom, and Albert, Jacques
- Date Created:
- 2008-03-10
-
- Resource Type:
- Article
- Creator:
- Johnson, D. C., Champion, H. G., Erickson, L. E., Hill, K. O., Malo, B., Theriault, S., Bilodeau, F., and Albert, Jacques
- Abstract:
- A variable diffraction efficiency phase mask is produced by focused ion beam, implanting a grating pattern into a fused SiO 2 substrate with a 100-nm-diam, 200keV Si beam. The substrate is prepared by cleaning and coating with a 20-nm-thick film of Al to dissipate the ion charge. The pattern consists of 930 lines, each 80μm long, at a pitch of 1.075μm, to obtain a 1-mm-long grating. The substrate is wet etched in a 1M% HF solution for about 45min to produce a phase mask with the desired diffraction efficiency. This phase mask is used to photoimprint Bragg gratings into standard hydrogenated single-mode telecommunication fibers using 193nm light from an ArF laser.
- Date Created:
- 1995-11-01
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- Resource Type:
- Article
- Creator:
- Girard, Lucas, Gruber, Stephan, Weber, Samuel, and Beutel, Jan
- Abstract:
- Frost cracking, the breakdown of rock by freezing, is one of the most important mechanical weathering processes acting on Earth's surface. Insights on the mechanisms driving frost cracking stem mainly from laboratory and theoretical studies. Transferring insights from such studies to natural conditions, involving jointed bedrock and heterogeneous thermal and hydrological properties, is a major challenge. We address this problem with simultaneous in situ measurements of acoustic emissions, used as proxy of rock damage, and rock temperature/moisture content. The 1 year data set acquired in an Alpine rock wall shows that (1) liquid water content has an important impact on freezing-induced rock damage, (2) sustained freezing can yield much stronger damage than repeated freeze-thaw cycling, and (3) that frost cracking occurs over the full range of temperatures measured extending from 0 down to -15°C. These new measurements yield a slightly different picture than previous field studies where ice segregation appears to play an important role. Key PointsRock liquid water content has an important impact on the freezing-induced damageSustained freezing can yield stronger damage than repeated freeze-thaw cyclingFrost cracking occurs on a wide range of temperatures extending from 0 to -15C
- Date Created:
- 2013-05-16
-
- Resource Type:
- Article
- Creator:
- Pommier-Budinger, Valerie, Tepylo, Nicolas, Budinger, Marc, and Huang, Xiao
- Abstract:
- The aeronautics industry is looking for ice protection systems consuming less energy. Electromechanical and especially piezoelectric solutions are a promising area of research for reducing average consumptions. This article provides an analytical model of a simple structure to assess the power and voltage required to obtain the delamination of the accumulated layer of ice at the support/ice interface. This model also allows analyzing the impact of the resonance frequencies used for supplying piezoelectric actuators on the tensile stress into PZT materials. Finally, this article assesses the effect of different ice - phobic coatings combined with piezoelectric ice protection systems. Experimental measurements of ice adhesion for different ice - phobic coatings allow evaluating the shear stress at which ice is detached from the surface. These results are then used to estimate - thanks to the proposed analytical model - the additional gain of power that would be provided by the use of such coatings.
- Date Created:
- 2016-06-10
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- Resource Type:
- Article
- Creator:
- Albert, Jacques and Andreyuk, Alexander
- Abstract:
- Phosphate glass samples doped with silver ions through a Na+-Ag+ ion-exchange process were treated in a hydrogen atmosphere at temperatures near 430 °C for durations ranging from 4 to 5 h. Such treatment causes metallic silver precipitation at the surface as well as nanoclustering of silver atoms under the surface under conditions very similar to those used for silicate glasses. The presence of silver clusters resulted in a characteristic coloring of the glass and was verified by the observation of a plasmon resonance peak near 410-420 nm in the absorption spectra. Applying a DC voltage between 1.4 and 2 kV at temperatures between 120 and 130 °C led to dissolution of the clusters in the area under the positive electrode, thereby bleaching the glass color. The use of a patterned doped-silicon electrode further led to the formation of a 300 nm thick surface relief on the glass surface and of a volume complex permittivity grating extending at least 4 μm under the surface. Such volume complex refractive index gratings may find applications in passive or active (laser) photonic devices in rare-earth doped phosphate glasses, where conventional bulk grating formation techniques have limited applicability.
- Date Created:
- 2014-01-01
-
- Resource Type:
- Article
- Creator:
- Temyanko, V. L., Honkanen, S., Schülzgen, A., Albert, Jacques, and Peyghambarian, N.
- Date Created:
- 2006-09-15
-
- Resource Type:
- Article
- Creator:
- Brebner, J. L., Bilodeau, F., Hill, K. O., Malo, B., Albert, Jacques, Templeton, I. M., and Johnson, D. C.
- Date Created:
- 1993-12-01
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- Resource Type:
- Article
- Creator:
- Trudeau, Y. B., Brebner, J. L., Hill, K. O., Kajrys, G., Albert, Jacques, Johnson, D. C., and Malo, B.
- Abstract:
- Germanium ions have been implanted in fused silica using ion beams having energies of 3 and 5 MeV and doses ranging from 1×1012 to 5×1014 ions/cm2. For wavelengths shorter than 400 nm, the optical absorption increases strongly with two absorption bands appearing at 244 and 212 nm. The ion-induced optical absorption can be bleached almost completely by irradiation with 249 nm excimer laser light. Ion implantation also increases the refractive index of silica near the substrate surface. At 632.8 nm a refractive index increase of more than 10-2 has been measured. This decreases by 4×10-3 upon bleaching with 249 nm light.
- Date Created:
- 1992-12-01
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- Resource Type:
- Article
- Creator:
- Zhou, Wenjun, Albert, Jacques, Zhang, Yang, and Shen, Changyu
- Abstract:
- A fiber twist sensor based on the surface plasmon resonance (SPR) effect of an Au-coated tilted fiber Bragg grating (TFBG) is proposed. The SPR response to the twist effect on an Au-coated TFBG (immersing in distilled water) is studied theoretically and experimentally. The results show that the transmission power around the wavelength of SPR changes with the twist angle. For the twist ranging from 0° to 180° in clockwise or anti-clockwise directions, the proposed sensor shows sensitivities of 0.037 dBm/° (S-polarized) and 0.039 dBm/° (P-polarized), which are almost 7.5 times higher than that of the current similar existing twist sensor.
- Date Created:
- 2014-01-01
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- Resource Type:
- Article
- Creator:
- Brebner, J. L., Albert, Jacques, Allard, L. B., and Verhaegen, M.
- Abstract:
- We have studied optical changes induced by ArF (6.4 eV/193 nm) excimer laser light illumination of high purity SiO2 implanted with Si2+ (5 MeV) at a fluence of 1015 ions/cm2. Optical absorption was measured from 3 eV (400 nm) to 8 eV (155 nm) and showed evidence of several well-defined absorption bands. A correlation in the bleaching behavior appears to exist between the so-called D band (located at 7.15 eV) and the well-known B2α band which is attributed to oxygen vacancies. Changes in the refractive index as a function of ArF illumination were measured and found to be in good quantitative agreement with a Kramers-Kronig analysis of the optical absorption data.
- Date Created:
- 1996-12-01
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- Resource Type:
- Article
- Creator:
- Leonelli, R., Albert, Jacques, Li, M. J., Najafi, S. I., Honkanen, S., and Wang, W. J.
- Abstract:
- A two-step double ion-exchange process is employed to produce dual-core waveguides in glass. First, potassium ion exchange is carried out at 400°C. Then, silver ion exchange is performed at 300°C. The fabricated waveguides have low losses, large single-mode regions, and more symmetrical profiles than single ion-exchanged waveguides. Etched gratings are also made in dual-core waveguides. Very high efficiencies are demonstrated in these waveguides.
- Date Created:
- 1991-12-01
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- Resource Type:
- Conference Proceeding
- Creator:
- Noble, James, Marshall, Stuart, Anslow, Craig, and Biddle, Robert
- Abstract:
- Developing applications for touch devices is hard. Developing touch based applications for multi-user input is harder. The Multi-Touch for Java (MT4j) toolkit supports developing touch based applications for multiple users. In this paper, we outline our experience using MT4j for developing a number of software applications to support developers working in co-located teams. Our experience using the toolkit will help developers to understand the nuances of the toolkit and design issues that can be applied to other toolkits for developing multi-user touch based applications.
- Date Created:
- 2016-10-21
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- Resource Type:
- Conference Proceeding
- Creator:
- Brubaker, Jed R., Handel, Mark, Yarosh, Svetlana, Bivens, Rena, Haimson, Oliver L., and Lingel, Jessa
- Abstract:
- Online systems often struggle to account for the complicated self-presentation and disclosure needs of those with complex identities or specialized anonymity. Using the lenses of gender, recovery, and performance, our proposed panel explores the tensions that emerge when the richness and complexity of individual personalities and subjectivities run up against design norms that imagine identity as simplistic or one-dimensional. These models of identity not only limit the ways individuals can express their own identities, but also establish norms for other users about what to expect, causing further issues when the inevitable dislocations do occur. We discuss the challenges in translating identity into these systems, and how this is further marred by technical requirements and normative logics that structure cultures and practices of databases, algorithms and computer programming.
- Date Created:
- 2015-01-01
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- Resource Type:
- Conference Proceeding
- Creator:
- Foster, Blair and Somayaji, Anil
- Abstract:
- This paper presents ObjRecombGA, a genetic algorithm framework for recombining related programs at the object file level. A genetic algorithm guides the selection of object files, while a robust link resolver allows working program binaries to be produced from the object files derived from two ancestor programs. Tests on compiled C programs, including a simple web browser and a well-known 3D video game, show that functional program variants can be created that exhibit key features of both ancestor programs. This work illustrates the feasibility of applying evolutionary techniques directly to commodity applications. Copyright 2010 ACM.
- Date Created:
- 2010-08-27
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- Resource Type:
- Conference Proceeding
- Creator:
- Van Oorschot, Paul C., Biddle, Robert, Forget, Alain, Chiasson, Sonia, and Stobert, Elizabeth
- Abstract:
- The underlying issues relating to the usability and security of multiple passwords are largely unexplored. However, we know that people generally have difficulty remembering multiple passwords. This reduces security since users reuse the same password for different systems or reveal other passwords as they try to log in. We report on a laboratory study comparing recall of multiple text passwords with recall of multiple click-based graphical passwords. In a one-hour session (short-term), we found that participants in the graphical password condition coped significantly better than those in the text password condition. In particular, they made fewer errors when recalling their passwords, did not resort to creating passwords directly related to account names, and did not use similar passwords across multiple accounts. After two weeks, participants in the two conditions had recall success rates that were not statistically different from each other, but those with text passwords made more recall errors than participants with graphical passwords. In our study, click-based graphical passwords were significantly less susceptible to multiple password interference in the short-term, while having comparable usability to text passwords in most other respects. Copyright 2009 ACM.
- Date Created:
- 2009-12-01
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- Resource Type:
- Article
- Creator:
- Kovalio, Jacob
- Date Created:
- 2001-07-01
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- Resource Type:
- Report
- Creator:
- Labiche, Yvan, Genero, Marcela, and Torre, Damiano
- Abstract:
- Context: The Unified Modeling Language (UML), with its 14 different diagram types, is the de-facto standard tool for objectoriented modeling and documentation. Since the various UML diagrams describe different aspects of one, and only one, software under development, they are not independent but strongly depend on each other in many ways. In other words, the UML diagrams describing a software must be consistent. Inconsistencies between these diagrams may be a source of the considerable increase of faults in software systems. It is therefore paramount that these inconsistencies be detected, analyzed and hopefully fixed. Objective: The aim of this article is to deliver a comprehensive summary of UML consistency rules as they are described in the literature to date to obtain an extensive and detailed overview of the current research in this area. Method: We performed a Systematic Mapping Study by following well-known guidelines. We selected 94 primary studies from a search with seven search engines performed in December 2012. Results: Different results are worth mentioning. First it appears that researchers tend to discuss very similar consistency rules, over and over again. Most rules are horizontal (98.07%) and syntactic (88.03%). The most used diagrams are the class diagram (71.28%), the state machine diagram (42.55%) and the sequence diagram (47.87%). Conclusion: The fact that many rules are duplicated in primary studies confirms the need for a well accepted list of consistency rules. This paper is a first step in this direction. Results indicate that much more work is needed to develop consistency rules for all 14 UML diagrams, in all dimensions of consistency (e.g., semantic and syntactic on the one hand, horizontal, vertical and evolution on the other hand).
- Date Created:
- 2014-01-01
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- Resource Type:
- Report
- Creator:
- Labiche, Yvan and Asoudeh, Nesa
- Abstract:
- In this paper we propose a method and a tool to generate test suites from extended finite state machines, accounting for multiple (potentially conflicting) objectives. We aim at maximizing coverage and feasibility of a test suite while minimizing similarity between its test cases and minimizing overall cost. Therefore, we define a multi-objective genetic algorithm that searches for optimal test suites based on four objective functions. In doing so, we create an entire test suite at once as opposed to test cases one at a time. Our approach is evaluated on two different case studies, showing interesting initial results.
- Date Created:
- 2013-10-01