352 research outputs found

    A Spatio-Temporal Probabilistic Framework for Dividing and Predicting Facial Action Units

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    This thesis proposed a probabilistic approach to divide the Facial Action Units (AUs) based on the physiological relations and their strengths among the facial muscle groups. The physiological relations and their strengths were captured using a Static Bayesian Network (SBN) from given databases. A data driven spatio-temporal probabilistic scoring function was introduced to divide the AUs into : (i) frequently occurred and strongly connected AUs (FSAUs) and (ii) infrequently occurred and weakly connected AUs (IWAUs). In addition, a Dynamic Bayesian Network (DBN) based predictive mechanism was implemented to predict the IWAUs from FSAUs. The combined spatio-temporal modeling enabled a framework to predict a full set of AUs in real-time. Empirical analyses were performed to illustrate the efficacy and utility of the proposed approach. Four different datasets of varying degrees of complexity and diversity were used for performance validation and perturbation analysis. Empirical results suggest that the IWAUs can be robustly predicted from the FSAUs in real-time and was found to be robust against noise

    Robust Modeling of Epistemic Mental States and Their Applications in Assistive Technology

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    This dissertation presents the design and implementation of EmoAssist: Emotion-Enabled Assistive Tool to Enhance Dyadic Conversation for the Blind . The key functionalities of the system are to recognize behavioral expressions and to predict 3-D affective dimensions from visual cues and to provide audio feedback to the visually impaired in a natural environment. Prior to describing the EmoAssist, this dissertation identifies and advances research challenges in the analysis of the facial features and their temporal dynamics with Epistemic Mental States in dyadic conversation. A number of statistical analyses and simulations were performed to get the answer of important research questions about the complex interplay between facial features and mental states. It was found that the non-linear relations are mostly prevalent rather than the linear ones. Further, the portable prototype of assistive technology that can aid blind individual to understand his/her interlocutor\u27s mental states has been designed based on the analysis. A number of challenges related to the system, communication protocols, error-free tracking of face and robust modeling of behavioral expressions /affective dimensions were addressed to make the EmoAssist effective in a real world scenario. In addition, orientation-sensor information from the phone was used to correct image alignment to improve the robustness in real life deployment. It was observed that the EmoAssist can predict affective dimensions with acceptable accuracy (Maximum Correlation-Coefficient for valence: 0.76, arousal: 0.78, and dominance: 0.76) in natural conversation. The overall minimum and maximum response-times are (64.61 milliseconds) and (128.22 milliseconds), respectively. The integration of sensor information for correcting the orientation has helped in significant improvement (16% in average) of accuracy in recognizing behavioral expressions. A user study with ten blind people shows that the EmoAssist is highly acceptable to them (Average acceptability rating using Likert: 6.0 where 1 and 7 are the lowest and highest possible ratings, respectively) in social interaction

    An Assessment of the Family Asteraceae at Shadullapur Upazila of Gaibandha District, Bangladesh with Particular Reference to Medicinal Plants

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    An assessment of the family Asteraceae at Sadullapur upazila of Gaibandha district, Bangladesh was carried out from August 2014 to October 2015. A total of 32 species under 27 genera belonging to the family Asteraceae were collected and identified. Frequent field trips were made during August 2014 to October 2015 to record medicinal information by interviewing local people of various age groups, mostly ranging between 18 to 67 years, including medicinal healers (herbalists/hakims). A total of 28 plant species under 24 genera of the family Asteraceae have been documented which are used for the treatment of 57 diseases/illness. In majority cases, leaves of the medicinal plants were found leading in terms of their use followed by whole plant, stem, bark, flower, seed and root. For each species scientific name, local name, chromosome number, voucher number, ailments to be treated and part(s) used are provided.

    Purchasing behavior for pirated products: a structural equation modeling approach on Bangladeshi consumers

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    The purpose of this study is to explore the factors influencing the Bangladeshi consumers’ perception toward purchasing pirated products. To explore these factors, this study had conducted a survey among the Bangladeshi consumers’. The data analysis was conducted through exploratory factor analysis, confirmatory factor analysis and structural equation modeling to test the hypotheses. Among the four variables, individual personalities and economic conditions are the most significant followed by social influences and pricing of pirated products. The outcome of this research showed a comprehensively integrated framework for policy maker and business enterprise to understand the dynamic relationships among dimensions of social influence, pricing, economy, and personality to understand the consumers’ perception toward purchasing pirated products. Further research is needed to examine these factors with additional samples before generalization can be made

    Understanding the Charge Carrier Conduction Mechanisms of Plasma-Polymerized 2-Furaldehyde Thin Films via DC Electrical Studies

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    Monomer 2-furaldehyde (FDH) was deposited onto the glass substrates in optimum conditions via a glow discharge using a capacitively coupled parallel plate reactor to obtain plasma polymerized 2-furaldehyde (PPFDH) thin films of different thicknesses. In order to realize the carrier conduction mechanisms, the direct current density against applied voltage (J-V) characteristics of these films with different thicknesses were investigated at different temperatures (T) in the voltage region from 0.5 to 49 V in Al/PPFDH/Al sandwich configuration. The J-V characteristics at various temperatures follow a power law of the form J ∞ Vn. In the low voltage region the values of n were recorded to be 0.80 ≤ n ≤ 1.12 and those in the high voltage region found to lie between 1.91 ≤ n ≤ 2.58, demonstrating the Ohmic conduction mechanism in the low voltage region and non-Ohmic conduction in the high voltage region. Theoretically calculated and experimental results of Schottky (βs) and Poole-Frenkel (βPF) coefficients display that the most probable conduction mechanism in PPFDH thin films is the Schottky type. Arrhenius plots of J vs. 1/T for an applied voltage of 5 V, the activation energies were 0.13 ± 0.02 and 0.50 ± 0.05 eV in the low and high temperature regions, respectively. However, for an applied voltage of 35 V, the activation energy values were found to be 0.11 ± 0.01 eV and 0.55 ± 0.02 eV, respectively in low and high temperature regions
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