Constraint-based Sequential Pattern Mining with Decision Diagrams

Constrained sequential pattern mining aims at identifying frequent patterns on a sequential database of items while observing constraints defined over the item attributes. We introduce novel techniques for constraint-based sequential pattern mining that rely on a multi-valued decision diagram representation of the database. Specifically, our representation can accommodate multiple item attributes and various constraint types, including a number of non-monotone constraints. To evaluate the applicability of our approach, we develop an MDD-based prefix-projection algorithm and compare its performance against a typical generate-and-check variant, as well as a state-of-the-art constraint-based sequential pattern mining algorithm. Results show that our approach is competitive with or superior to these other methods in terms of scalability and efficiency.Comment: AAAI201

Lazier Than Lazy Greedy

Is it possible to maximize a monotone submodular function faster than the widely used lazy greedy algorithm (also known as accelerated greedy), both in theory and practice? In this paper, we develop the first linear-time algorithm for maximizing a general monotone submodular function subject to a cardinality constraint. We show that our randomized algorithm, STOCHASTIC-GREEDY, can achieve a $(1-1/e-\varepsilon)$ approximation guarantee, in expectation, to the optimum solution in time linear in the size of the data and independent of the cardinality constraint. We empirically demonstrate the effectiveness of our algorithm on submodular functions arising in data summarization, including training large-scale kernel methods, exemplar-based clustering, and sensor placement. We observe that STOCHASTIC-GREEDY practically achieves the same utility value as lazy greedy but runs much faster. More surprisingly, we observe that in many practical scenarios STOCHASTIC-GREEDY does not evaluate the whole fraction of data points even once and still achieves indistinguishable results compared to lazy greedy.Comment: In Proc. Conference on Artificial Intelligence (AAAI), 201

Comparative Evaluation of Different Computational Models for Performance of Air Source Heat Pumps Based on Real World Data

AbstractTo reduce energy usage and CO2 emission due to heating, heat pumps have turned out a good option. For example, to obtain a net zero house, often a combination of solar panels and a heat pump is used. A computational model of the performance of a heat pump provides a useful tool for prediction and decision making. In this paper, six variations of such computational models are discussed and evaluated. Evaluation was based on real world empirical data for 8 different domestic situations. The evaluation took place by determining the most optimal values for the parameters of each of the models for the given data, and then considering the remaining error

Are You Applying to More Than One Specialty?

Although the majority of U.S. medical students predominantly apply to only one specialty, some apply to more than one. When it comes to emergency medicine (EM), applicants may apply to additional specialties due to several reasons: being international medical graduates as well as their inability to make a decision regarding the choice of specialty, fear from the growing competitiveness of EM, or the desire to stay in a specific geographic area. Accordingly, in this article we aim to guide medical students through the process of applying to more than one specialty, including using the Electronic Residency Application Service application, writing a personal statement, getting letters of recommendation, and an Early Match. Moreover, we elaborate on the effect of applying to more than one specialty on a student's application to a residency in EM

Research Trends In Select Science Faculties Of University Of Jammu.

The study attempts to analyze and report research trends in various subject fields of the faculty of Sciences, Life Sciences and Mathematical Science of University of Jammu. The analysis is based on the data gathered from SCOPUS as on March-May, 2011. The data gathered were meticulously analysed to depict research trends in different Departments and Subject areas viz: collaboration at various levels, authorship patterns, and citation profile. The findings reveal that although the faculties under study have witnessed potential growth in terms of research output. However, several departments are still lagging behind in terms of productivity and quality research, which is evident from low research output and citation count received by the publications. Current study is confined to 1237 research contributions that were published during 39 years from (1972 to May, 2011), by the 15 departments under the faculty of Sciences, Life Sciences and Mathematical Sciences of University of Jammu indexed by SCOPUS. The study is beneficial to highlight potential areas of research and will act as a tool for addressing problems at research front in those subject areas where research output is very meagre

Research Trends In Select Science Faculties Of University Of Jammu.

The study attempts to analyze and report research trends in various subject fields of the faculty of Sciences, Life Sciences and Mathematical Science of University of Jammu. The analysis is based on the data gathered from SCOPUS as on March-May, 2011. The data gathered were meticulously analysed to depict research trends in different Departments and Subject areas viz: collaboration at various levels, authorship patterns, and citation profile. The findings reveal that although the faculties under study have witnessed potential growth in terms of research output. However, several departments are still lagging behind in terms of productivity and quality research, which is evident from low research output and citation count received by the publications. Current study is confined to 1237 research contributions that were published during 39 years from (1972 to May, 2011), by the 15 departments under the faculty of Sciences, Life Sciences and Mathematical Sciences of University of Jammu indexed by SCOPUS. The study is beneficial to highlight potential areas of research and will act as a tool for addressing problems at research front in those subject areas where research output is very meagre