Proceedings of 2017 IEEE Conference on Communications and Network Security (CNS) in Las Vegas, NV, USA, USA on 9-11 Oct. 2017.We address security and trust in the context of a commercial IP camera. We take a hands-on approach, as we not only define abstract vulnerabilities, but we actually implement the attacks on a real camera. We then discuss the nature of the attacks and the root cause; we propose a formal model of trust that can be used to address the vulnerabilities by explicitly constraining compositionality for trust relationships., Conference paper, Published.
Thermal Performance of Exterior Envelopes of Whole Buildings X International Conference, Clearwater Beach, Florida, USA, December 02, 2007. This climate sensitivity study studied the effects of wind-driven rain on a stucco-clad wall using the advanced hygrothermal model, hygIRC. Simulations were made for a number of climatic conditions based on the moisture index (MI) and for amounts of water deposited inside a wall. The moisture index was based on the severity of a given climate in respect to wall assemblies and the degree of wetting and drying to which a wall could potentially be subjected. The failure criteria was the concurrent occurrence of temperature and relative humidity above thresholds of 10oC and 95% respectively, for ninety consecutive days at any location of wood-based material in the wall., Conference paper, Published. A version of this document is published in: Thermal Performance of Exterior Envelopes of Whole Buildings X International Conference, Clearwater Beach, FL., Dec. 2-7, 2007, pp. 1-15.
Proceedings of the 18th IEEE Symposium on Logic in Computer Science (LICS-03), Ottawa, ON, 2003. The spectrum of a first-order sentence is the set of cardinalities of its finite models. Relatively little is known about the subclasses of spectra that are obtained by looking only at sentences with a specific signature. In this paper, we study natural subclasses of spectra and their closure properties under simple subdiagonal functions. We show that many natural closure properties turn out to be equivalent to the collapse of potential spectrum hierarchies. We prove all of our results using explicit transformations on first-order structures., Conference paper, Published.
Proceedings of 2017 International Conference on Noise and Fluctuations (ICNF), Vilnius, Lithuania on 20-23 June 2017. Segmentation of the developing insect body is preceded by cell-specific gene expression. In fruit flies (Drosophila), pair-rule genes are expressed in spatial stripes specifying segment fates. Transcription of the even-skipped (eve) pair-rule gene was recently shown to proceed in noisy bursts. Here, we develop a stochastic model of eve transcription from DNA to mRNA. This indicates that eve transcription proceeds at two rates, with a slow rate providing basal production and a fast rate allowing for high mRNA output. This two-rate transcription may afford more reliability in mRNA output, and therefore the protein levels which specify cell type, than a simple on-off (one-rate) mechanism., Conference paper, Published.
Proceedings of 2012 European Intelligence and Security Informatics Conference (EISIC) in Odense, Denmark 22-24 Aug. 2012. Much of the information exchanged between agents over a network is encapsulated in XML documents. An XML document has a tree structure, and the meaning of the document can be understood in terms of a set of label-value pairs. The content of a document is often secured through digital signatures applied to different sections, while the document is passed between several agents. In this paper, we illustrate that this process is insecure in the sense that a malicious agent can deceive an honest agent to hold beliefs that are untrue. We provide a formal framework for analyzing the security of structured documents, based on the implicit epistemic impact that a signed document will have on a recipient. This kind of analysis can provide significant insight into deception and fraud detection., Conference paper, Published.
Proceedings of 2013 Humaine Association Conference on Affective Computing and Intelligent Interaction, Geneva, Switzerland, 2-5 Sept. 2013. We present the results of a study that explored the emotions experienced by students during interaction with an educational game for math (Heroes of Math Island). Starting from emotion frameworks in affective computing and education, we considered a larger set of emotions than in related research. For emotion labeling, we employed a standard method that relies on trained judges to report emotions over 20-second intervals. However, we asked judges to report all observed emotions in each interval, as opposed to only choosing one, as is standard practice. This variation allows us to discuss the appropriateness of this interval for emotion labeling. We present a detailed analysis of inter-coder reliability, both aggregated and over individual students, that considers not only the matching by judges over emotion type, but also the number of emotions detected., Conference paper, Published., Peer reviewed
Proceedings from the 23rd Annual ACM Conference on Innovation and Technology in Computer Science Education. Since computing education began, we have sought to learn why students struggle in computer science and how to identify these at-risk students as early as possible. Due to the increasing availability of instrumented coding tools in introductory CS courses, the amount of direct observational data of student working patterns has increased significantly in the past decade, leading to a flurry of attempts to identify at-risk students using data mining techniques on code artifacts. The goal of this work is to produce a systematic literature review to describe the breadth of work being done on the identification of at-risk students in computing courses. In addition to the review itself, which will summarize key areas of work being completed in the field, we will present a taxonomy (based on data sources, methods, and contexts) to classify work in the area., Peer reviewed, Conference paper, Published.
14th Canadian Conference on Building Science and Technology, Toronto, Canada, October 29th-30th, 2014.
It is essential to design and operate buildings with good indoor air quality as people spend most of their time indoor. Their productivity, comfort and health depend on the quality of the indoor air. In addition to other air quality parameters, indoor humidity and temperature need to be controlled and maintained to acceptable ranges. These conditions may not be uniform within the house/building due to local heat and moisture sources and absence of an effective indoor air mixing mechanism as in the case of in buildings with baseboard heating systems. Localized high humidity creates favourable conditions for localized mold growth, poor indoor air quality and building envelope damage. In this paper, the indoor humidity and temperature distributions within four suites (designated as Suite ‘A’, ‘B’, ‘C’ and ‘D’) in a six-storey multi-residential building are studied. A total of 22 rooms are monitored with indoor temperature and relative humidity data loggers, and the outdoor climatic conditions are measured with a weather station for over a year. The hygrothermal performances of exterior walls in the master bedrooms of the respective suites are assessed. Analysis of the measured data suggests that the temperature variations between the rooms (bedrooms, living room, kitchen excluding bathroom) are relatively low during the summer period (mean temperature difference less than 1oC) compared to the winter period where the variations between the rooms can be as high as 2oC. The excess humidity differences between the rooms, excluding the kitchens, are in the range of 0.2 g/m 3 to 1.0 g/m 3 during both winter and summer periods, whereas the excess humidity fluctuations within the rooms are fairly the same and have standard deviation values between 0.8 g/m 3 and 1.0 g/m 3. Excess humidity is defined as the difference between the indoor and outdoor absolute humidities, quantities that
are derived from the simultaneously measured temperature and relative humidity of the indoor and outdoor locations. Hygrothermal simulation results of exterior wall systems indicate that, in a mild coastal climate, the winter average indoor relative humidity shall be below 43% (for a seasonal average indoor temperature of 20oC) to avoid building envelope moisture damage., Peer reviewed article, Published.
Proceedings of Building Physics Symposium: 29 October 2008, Leuven, Belgium.
This paper describes the use of a whole building hygrothermal model (HAMFitPlus) to analyze the energy savings resulting from three programmable thermostat setting schemes in a real occupied residential house. It discusses the effect of these schemes on the indoor relative humidity and moisture performance. In the first thermostat-setting scheme, the indoor temperature is maintained constant at 21 at all time (no set-back). In the second thermostat-setting scheme, the indoor temperature is maintained at 21ºC from 7:00 to 21:00 h, and then setback to 17ºC for the remaining hours (21:00 to 7:00 h)., Conference paper, Published. A version of this document is published in: Building Physics Symposium, Lueven, Belgium, October 29-31, 2008, pp. 1-5.
Proceedings of the Twenty-Fourth International Joint Conference on Artificial Intelligence in Buenos Aires, Argentina, 25–31 July 2015. Belief revision is concerned with incorporating new information into a pre-existing set of beliefs. When the new information comes from another agent, we must first determine if that agent should be trusted. In this paper, we define trust as a pre-processing step before revision. We emphasize that trust in an agent is often restricted to a particular domain of expertise. We demonstrate that this form of trust can be captured by associating a state partition with each agent, then relativizing all reports to this partition before revising. We position the resulting family of trust-sensitive revision operators within the class of selective revision operators of Ferme and Hansson, and we examine its properties. In particular, we show how trust-sensitive revision is manipulable, in the sense that agents can sometimes have incentive to pass on misleading information. When multiple reporting agents are involved, we use a distance function over states to represent differing degrees of trust; this ensures that the most trusted reports will be believed., Conference paper, Published.
Proceedings of 12th International Heat Transfer Conference: 18 August 2002, Grenoble, France. Using numerical modelling to simulate and predict the hygrothermal (i.e., combined thermal and moisture)performance of building envelopes is very recent. Key questions include: how to model accurately coupled heat-air and capillary moisture transports in building envelope components; a satisfactory definition of a set of representative environmental boundary conditions to be used for long-term hygrothermal calculations; how to characterize the moisture- and temperature-dependent properties; the effect of aging and cyclic environmental conditions on porous building materials; and how to develop sound criteria to predict the moisture durability of building envelope components. This paper presents the findings of a research project involving detailed hygrothermal modelling. The heat, air and moisture results demonstrated that the in-house model could be adapted successfully for high-rise building calculations. The findings also show how the long-term hygrothermal performance of typical wall systems can be assessed using numerical modelling. A short description of an advanced in-house heat, air and moisture model, hygIRC, is also presented., Conference paper, Published. A version of this document is published in: 12th International Heat Transfer Conference, Grenoble, France, Sept. 18, 2002, pp. 165-170.