Information Technology
An Antimicrobial Prescription Surveillance System that Learns from Experience
Beaudoin, Mathieu (Université de Sherbrooke) | Kabanza, Froduald (Université de Sherbrooke) | Nault, Vincent (Université de Sherbrooke) | Valiquette, Louis (Université de Sherbrooke)
Inappropriate prescribing of antimicrobials is a major clinical and health concern, as well as a financial burden, in hospitals worldwide. In this paper, we describe a deployed automated antimicrobial prescription surveillance system that has been assisting hospital pharmacists in identifying and reporting inappropriate antimicrobial prescriptions. One of the key characteristics of this system is its ability to learn new rules for detecting inappropriate prescriptions based on previous false alerts. The supervised learning algorithm combines instance-based learning and rule induction techniques. It exploits temporal abstraction to extract a meaningful time interval representation from raw clinical data, and applies nearest neighbor classification with a distance function on both temporal and non-temporal parameters. The learning capability is valuable both in configuring the system for initial deployment and improving its long term use. We give an overview of the application, point to lessons learned so far and provide insight into the machine learning capability.
Multi-Armed Bandit with Budget Constraint and Variable Costs
Ding, Wenkui (Tsinghua University) | Qin, Tao (Microsoft Research Asia) | Zhang, Xu-Dong (Tsinghua University) | Liu, Tie-Yan (Microsoft Research Asia)
We study the multi-armed bandit problems with budget constraint and variable costs (MAB-BV). In this setting, pulling an arm will receive a random reward together with a random cost, and the objective of an algorithm is to pull a sequence of arms in order to maximize the expected total reward with the costs of pulling those arms complying with a budget constraint. This new setting models many Internet applications (e.g., ad exchange, sponsored search, and cloud computing) in a more accurate manner than previous settings where the pulling of arms is either costless or with a fixed cost. We propose two UCB based algorithms for the new setting. The first algorithm needs prior knowledge about the lower bound of the expected costs when computing the exploration term. The second algorithm eliminates this need by estimating the minimal expected costs from empirical observations, and therefore can be applied to more real-world applications where prior knowledge is not available. We prove that both algorithms have nice learning abilities, with regret bounds of O(ln B). Furthermore, we show that when applying our proposed algorithms to a previous setting with fixed costs (which can be regarded as our special case), one can improve the previously obtained regret bound. Our simulation results on real-time bidding in ad exchange verify the effectiveness of the algorithms and are consistent with our theoretical analysis.
SEPIA: A Scalable Game Environment for Artificial Intelligence Teaching and Research
Sosnowski, Scott (Case Western Reserve University) | Ernsberger, Tim (Case Western Reserve University) | Cao, Feng (Case Western Reserve University) | Ray, Soumya (Case Western Reserve University)
We describe a game environment we have developed that we call the Strategy Engine for Programming Intelligent Agents (SEPIA). SEPIA is based on real-time strategy games, but modified extensively to preferentially support the development of artificial agents rather than human play. Through flexible configuration options, SEPIA is designed to be pedagogically scalable: suitable for use at the undergraduate and graduate levels, and also as a research testbed. We also describe assignments and our experiences with this environment in undergraduate and graduate classes.
Learning Compact Visual Descriptors for Low Bit Rate Mobile Landmark Search
Duan, Ling-Yu (Peking University) | Chen, Jie (Peking University) | Ji, Rongrong (Peking University) | Huang, Tiejun (Peking University) | Gao, Wen (Peking University)
Coming with the ever growing computational power of mobile devices, mobile visual search have undergone an evolution in techniques and applications. A significant trend is low bit rate visual search, where compact visual descriptors are extracted directly over a mobile and delivered as queries rather than raw images to reduce the query transmission latency. In this article, we introduce our work on low bit rate mobile landmark search, in which a compact yet discriminative landmark image descriptor is extracted by using location context such as GPS, crowd-sourced hotspot WLAN, and cell tower locations. The compactness originates from the bag-of-words image representation, with an offline learning from geotagged photos from online photo sharing websites including Flickr and Panoramio. The learning process involves segmenting the landmark photo collection by discrete geographical regions using Gaussian mixture model, and then boosting a ranking sensitive vocabulary within each region, with an “entropy” based descriptor compactness feedback to refine both phases iteratively. In online search, when entering a geographical region, the codebook in a mobile device are downstream adapted to generate extremely compact descriptors with promising discriminative ability. We have deployed landmark search apps to both HTC and iPhone mobile phones, working over the database of million scale images in typical areas like Beijing, New York, and Barcelona, and others. Our descriptor outperforms alternative compact descriptors (Chen et al. 2009; Chen et al., 2010; Chandrasekhar et al. 2009a; Chandrasekhar et al. 2009b) with significant margins. Beyond landmark search, this article will summarize the MPEG standarization progress of compact descriptor for visual search (CDVS) (Yuri et al. 2010; Yuri et al. 2011) towards application interoperability.
Seven Challenges in Parallel SAT Solving
Hamadi, Youssef (Microsoft Research, 7 JJ Thomson Avenue, Cambridge CB3 0FB, United Kingdom) | Wintersteiger, Christoph (Microsoft Research, 7 JJ Thomson Avenue, Cambridge CB3 0FB, United Kingdom)
This paper provides a broad overview of the situation in Parallel SAT Solving. A set of challenges to researchers is presented which, we believe, must be met to ensure the practical applicability of Parallel SAT Solvers in the future. All these challenges are described informally, but put into perspective with related research results, and a (subjective) grading of difficulty for each of them is provided.
A Virtual Archive for the History of AI
Buchanan, Bruce G. (University of Pittsburgh) | Eckroth, Joshua (The Ohio State University) | Smith, Reid (Marathon Oil Corporation)
Publications that have influenced the growth of artificial intelligence are often difficult to obtain. We first collected titles of several thousand publications from many well-known sources and then selected about 1850 titles considered to be especially influential. We have identified, and in a few cases created, online versions of about half of these “classics in AI.” Searchable text of the documents enables additional analysis of trends and influences. Integration into the rest of the AITopics information portal contextualizes the classic publications.
User-Centric Indoor Air Quality Monitoring on Mobile Devices
Jiang, Yifei (University of Colorado, Boulder) | Li, Kun (University of Colorado, Boulder) | Piedrahita, Ricardo (University of Colorado, Boulder) | Yun, Xiang (University of Michigan) | Tian, Lei (University of Colorado, Boulder) | Mansata, Omkar M. (University of Michigan) | Lv, Qin (University of Colorado, Boulder) | Dick, Robert P. (University of Michigan) | Hannigan, Michael (University of Colorado, Boulder) | Shang, Li (University of Colorado, Boulder)
Since people spend a majority of their time indoors, indoor air quality (IAQ) can have a significant impact on human health, safety, productivity, and comfort. Due to the diversity and dynamics of people's indoor activities, it is important to monitor IAQ for each individual. Most existing air quality sensing systems are stationary or focus on outdoor air quality. In contrast, we propose MAQS, a user-centric mobile sensing system for IAQ monitoring. MAQS users carry portable, indoor location tracking and IAQ sensing devices that provide personalized IAQ information in real time. To improve accuracy and energy efficiency, MAQS incorporates three novel techniques: (1) an accurate temporal n-gram augmented Bayesian room localization method that requires few Wi-Fi fingerprints; (2) an air exchange rate based IAQ sensing method, which measures general IAQ using only CO$_2$ sensors; and (3) a zone-based proximity detection method for collaborative sensing, which saves energy and enables data sharing among users. MAQS has been deployed and evaluated via a real-world user study. This evaluation demonstrates that MAQS supports accurate personalized IAQ monitoring and quantitative analysis with high energy efficiency. We also found that study participants frequently experienced poor IAQ.
Personality Traits Recognition on Social Network - Facebook
Alam, Firoj (University of Trento) | Stepanov, Evgeny A. (University of Trento) | Riccardi, Giuseppe (University of Trento)
For the natural and social interaction it is necessary to understand human behavior. Personality is one of the fundamental aspects, by which we can understand behavioral dispositions. It is evident that there is a strong correlation between users’ personality and the way they behave on online social network (e.g., Facebook). This paper presents automatic recognition of Big-5 personality traits on social network (Facebook) using users’ status text. For the automatic recognition we studied different classification methods such as SMO (Sequential Minimal Optimization for Support Vector Machine), Bayesian Logistic Regression (BLR) and Multinomial Naïve Bayes (MNB) sparse modeling. Performance of the systems had been measured using macro-averaged precision, recall and F1; weighted average accuracy (WA) and un-weighted average accuracy (UA). Our comparative study shows that MNB performs better than BLR and SMO for personality traits recognition on the social network data.