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2015

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Articles 1411 - 1440 of 12617

Full-Text Articles in Physical Sciences and Mathematics

Experience Report: An Industrial Experience Report On Test Outsourcing Practices, Xin Xia, David Lo, Pavneet Singh Kochhar, Zhenchang Xing, Xinyu Wang, Shanping Li Nov 2015

Experience Report: An Industrial Experience Report On Test Outsourcing Practices, Xin Xia, David Lo, Pavneet Singh Kochhar, Zhenchang Xing, Xinyu Wang, Shanping Li

Research Collection School Of Computing and Information Systems

Nowadays, many companies contract their testing functionalities out to third-party IT outsourcing companies. This process referred to as test outsourcing is common in the industry, yet it is rarely studied in the research community. In this paper, to bridge the gap, we performed an empirical study on test outsourcing with 10 interviewees and 140 survey respondents. We investigated various research questions such as the types, the process, and the challenges of test outsourcing, and the differences between test outsourcing and in-house testing. We found customer satisfaction, tight project schedule, and domain unfamiliarity are the top-3 challenges faced by the testers. …


Real-Time Detection Of Seat Occupancy And Hogging, Huy Hoang Nguyen, Nakul Gulati, Youngki Lee, Rajesh Krishna Balan Nov 2015

Real-Time Detection Of Seat Occupancy And Hogging, Huy Hoang Nguyen, Nakul Gulati, Youngki Lee, Rajesh Krishna Balan

Research Collection School Of Computing and Information Systems

In this paper, we propose a cheap and effective solution to detect if specific seats at a shared public table are occupied -- either by humans or by objects (i.e., the seats are being "hogged"). The hogging of seats, in particular, is a big problem for our campus library and required a large amount of manpower to correct (to find and clear hogged seats). We propose using two different cheap sensors, a capacitance sensor and an infrared (IR) sensor, to solve this problem. In the rest of this paper, we show how using these sensors can accurately determine if a …


Vireo-Tno @ Trecvid 2015: Multimedia Event Detection, Hao Zhang, Yi-Jie Lu, Maaike De Boer, Frank Ter Haar, Zhaofan Qiu, Klamer Schutte, Wessel Kraaij, Chong-Wah Ngo Nov 2015

Vireo-Tno @ Trecvid 2015: Multimedia Event Detection, Hao Zhang, Yi-Jie Lu, Maaike De Boer, Frank Ter Haar, Zhaofan Qiu, Klamer Schutte, Wessel Kraaij, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

This paper presents an overview and comparative analysis of our systems designed for the TRECVID 2015 [1] multimedia event detection (MED) task. We submitted 17 runs, of which 5 each for the zeroexample, 10-example and 100-example subtasks for the Pre-Specified (PS) event detection and 2 runs for the 10-example subtask for the Ad-Hoc (AH) event detection. We did not participate in the Interactive Run. This year we focus on three different parts of the MED task: 1) extending the size of our concept bank and combining it with improved dense trajectories; 2) exploring strategies for semantic query generation (SQG); and …


Multimedia Event Detection: Strong By Integration, Hao Zhang, Maaike De Boer, Yi-Jie Lu, Klamer Schutte, Chong-Wah Ngo, Chong-Wah Ngo Nov 2015

Multimedia Event Detection: Strong By Integration, Hao Zhang, Maaike De Boer, Yi-Jie Lu, Klamer Schutte, Chong-Wah Ngo, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

No abstract provided.


Whom Should We Sense In 'Social Sensing' - Analyzing Which Users Work Best For Social Media Now-Casting, Jisun An, Ingmar Weber Nov 2015

Whom Should We Sense In 'Social Sensing' - Analyzing Which Users Work Best For Social Media Now-Casting, Jisun An, Ingmar Weber

Research Collection School Of Computing and Information Systems

Given the ever increasing amount of publicly available social media data, there is growing interest in using online data to study and quantify phenomena in the offline 'real' world. As social media data can be obtained in near real-time and at low cost, it is often used for 'now-casting' indices such as levels of flu activity or unemployment. The term 'social sensing' is often used in this context to describe the idea that users act as 'sensors', publicly reporting their health status or job losses. Sensor activity during a time period is then typically aggregated in a 'one tweet, one …


Empirical Line Lists And Absorption Cross Sections For Methane At High Temperatures, R. J. Hargreaves, P. F. Bernath, J. Bailey, M. Dulick Nov 2015

Empirical Line Lists And Absorption Cross Sections For Methane At High Temperatures, R. J. Hargreaves, P. F. Bernath, J. Bailey, M. Dulick

Chemistry & Biochemistry Faculty Publications

Hot methane is found in many "cool" sub-stellar astronomical sources including brown dwarfs and exoplanets, as well as in combustion environments on Earth. We report on the first high-resolution laboratory absorption spectra of hot methane at temperatures up to 1200 K. Our observations are compared to the latest theoretical spectral predictions and recent brown dwarf spectra. The expectation that millions of weak absorption lines combine to form a continuum, not seen at room temperature, is confirmed. Our high-resolution transmittance spectra account for both the emission and absorption of methane at elevated temperatures. From these spectra, we obtain an empirical line …


Towards Sustainable Digital Humanities Software, George K. Thiruvathukal, Shilpika Shilpika, Nicholas J. Hayward, Saulo Aguiar, Konstantin Läufer Nov 2015

Towards Sustainable Digital Humanities Software, George K. Thiruvathukal, Shilpika Shilpika, Nicholas J. Hayward, Saulo Aguiar, Konstantin Läufer

Computer Science: Faculty Publications and Other Works

Our work in software quality for digital humanities was borne of an effort to address sustainable practices in scientific software development, where the speaker (Thiruvathukal) co-authored a position paper on the case for software engineering in scientific software development as part of an all-encompassing strategy to create more sustainable scientific software (an example of a well-known scientific software package is LINPACK). In this position paper, we addressed how “progress in scientific research is dependent on the quality and accessibility of software at all levels". This progress depends on embracing the best traditional--and emergent--practices in software engineering, especially agile practices that …


Extending The Teknomo-Fernandez Background Image Generation Algorithm On The Hsv Colour Space, Patricia Angela R. Abu, Proceso L. Fernandez Jr Nov 2015

Extending The Teknomo-Fernandez Background Image Generation Algorithm On The Hsv Colour Space, Patricia Angela R. Abu, Proceso L. Fernandez Jr

Department of Information Systems & Computer Science Faculty Publications

Background subtraction, a procedure required in many video analysis applications such as object tracking , is dependent on the model background image. One efficient algorithm for background image generation is the Teknomo-Fernandez (TF) Algorithm, which uses modal values and a tournament-like strategy to produce a good background image very quickly. A previous study showed that the TF algorithm can be extended from the original 3 frames per tournament (T F 3) to T F 5 and T F 7, resulting in increased accuracies at a cost of increased processing times. In this study, we explore extending the T F 3, …


Reversible Peg Solitaire On Graphs, John Engbers, Christopher Stocker Nov 2015

Reversible Peg Solitaire On Graphs, John Engbers, Christopher Stocker

Mathematics, Statistics and Computer Science Faculty Research and Publications

The game of peg solitaire on graphs was introduced by Beeler and Hoilman in 2011. In this game, pegs are initially placed on all but one vertex of a graph G. If xyz forms a path in G and there are pegs on vertices x and y but not z, then a jump places a peg on z and removes the pegs from x and y. A graph is called solvable if, for some configuration of pegs occupying all but one vertex, some sequence of jumps leaves a single peg. We study the game of reversible peg …


Seismic Surveys And Marine Turtles: An Underestimated Global Threat?, Sarah E. Nelms, Wendy Dow Piniak, Caroline R. Weir, Brendan J. Godley Nov 2015

Seismic Surveys And Marine Turtles: An Underestimated Global Threat?, Sarah E. Nelms, Wendy Dow Piniak, Caroline R. Weir, Brendan J. Godley

Environmental Studies Faculty Publications

Seismic surveys are widely used in marine geophysical oil and gas exploration, employing airguns to produce sound-waves capable of penetrating the sea floor. In recent years, concerns have been raised over the biological impacts of this activity, particularly for marine mammals. While exploration occurs in the waters of at least fifty countries where marine turtles are present, the degree of threat posed by seismic surveys is almost entirely unknown. To investigate this issue, a mixed-methods approach involving a systematic review, policy comparison and stakeholder analysis was employed and recommendations for future research were identified. This study found that turtles have …


Cnl: Collective Network Linkage Across Heterogeneous Social Platforms, Ming Gao, Ee-Peng Lim, David Lo, Feida Zhu, Philips Kokoh Prasetyo, Aoying Zhou Nov 2015

Cnl: Collective Network Linkage Across Heterogeneous Social Platforms, Ming Gao, Ee-Peng Lim, David Lo, Feida Zhu, Philips Kokoh Prasetyo, Aoying Zhou

Research Collection School Of Computing and Information Systems

The popularity of social media has led many users to create accounts with different online social networks. Identifying these multiple accounts belonging to same user is of critical importance to user profiling, community detection, user behavior understanding and product recommendation. Nevertheless, linking users across heterogeneous social networks is challenging due to large network sizes, heterogeneous user attributes and behaviors in different networks, and noises in user generated data. In this paper, we propose an unsupervised method, Collective Network Linkage (CNL), to link users across heterogeneous social networks. CNL incorporates heterogeneous attributes and social features unique to social network users, handles …


Using Geometry To Manipulate Long-Range Correlation Of Light Inside Disordered Media, Raktim Sarma, Alexey Yamilov, Pauf Neupane, Hui Cao Nov 2015

Using Geometry To Manipulate Long-Range Correlation Of Light Inside Disordered Media, Raktim Sarma, Alexey Yamilov, Pauf Neupane, Hui Cao

Physics Faculty Research & Creative Works

We demonstrate an effective approach of modifying the long-range spatial correlation for light propagating inside random photonic waveguides by varying the shape of the waveguide. The functional form of spatial correlation is no longer universal in the regime of diffusive transport and becomes shape dependent due to the nonlocal nature of wave propagation. The spatial dependence of the correlation may become asymmetric for light incident from opposite ends of the waveguide. This work opens the door to control nonlocal effects in mesoscopic transport of waves by tailoring the geometry of random systems. .


Selective Iodination Using Diaryliodonium Salts, William H. Miller Iv Nov 2015

Selective Iodination Using Diaryliodonium Salts, William H. Miller Iv

Department of Chemistry: Dissertations, Theses, and Student Research

Aryl iodides have become widely recognized as versatile synthetic intermediates, owing to aromatic iodine’s excellent ability to participate in oxidative addition reactions. Iodoarenes readily undergo a variety of synthetic transformations including metal catalyzed cross-coupling reactions, diaryliodonium chemistry, formation of organometallics through reduction or metal-halogen exchange, as well as classical SN2 type chemistry. Because a wide array of transformations are available for aryl iodides, organic molecules containing this moiety often serve as vital precursors to highly desirable pharmaceuticals.

This thesis describes a simple and selective two-step approach to the formation of aryl iodides. This method proceeds through an easily …


New Transitions And Feeding Of The JΠ=(8+) Isomer In 186Re, David A. Matters [*], Nikolaos Fotiades, James J. Carroll, Christopher J. Chiara, John W. Mcclory, Toshihiko Kawano, Ronald O. Nelson, Matthew Devlin Nov 2015

New Transitions And Feeding Of The JΠ=(8+) Isomer In 186Re, David A. Matters [*], Nikolaos Fotiades, James J. Carroll, Christopher J. Chiara, John W. Mcclory, Toshihiko Kawano, Ronald O. Nelson, Matthew Devlin

Faculty Publications

The spallation neutron source at the Los Alamos Neutron Science Center Weapons Neutron Research facility was used to populate excited states in 186Re via (n,2nγ) reactions on an enriched 187Re target. Gamma rays were detected with the GErmanium Array for Neutron Induced Excitations spectrometer, a Compton-suppressed array of 18 HPGe detectors. Incident neutron energies were determined by the time-of-flight technique and used to obtain γ-ray excitation functions for the purpose of identifying γ rays by reaction channel. Analysis of the singles γ-ray spectrum gated on the neutron energy range 10≤En≤25MeV resulted in five transitions and one …


The Impact Of Solar Wind Ulf Bz Fluctuations On Geomagnetic Activity For Viscous Timescales During Strongly Northward And Southward Imf, A. Osmane, A. P. Dimmock, R. Naderpour, T. I. Pulkkinen, K. Nykyri Nov 2015

The Impact Of Solar Wind Ulf Bz Fluctuations On Geomagnetic Activity For Viscous Timescales During Strongly Northward And Southward Imf, A. Osmane, A. P. Dimmock, R. Naderpour, T. I. Pulkkinen, K. Nykyri

Publications

We analyze more than 17 years of OMNI data to statistically quantify the impact of IMF Bz fluctuations on AL by using higher-order moments in the AL-distribution as a proxy. For strongly southward interplanetary magnetic field (IMF), the AL distribution function is characterized by a decrease of the skewness, a shift of its peak from −30 nT to −200 nT, and a broadening of the distribution core. During northward IMF, the distribution of AL is characterized by a significant reduction of the standard deviation and weight in the tail. Following this characterization of AL for southward and northward IMF, we …


Abundance, Stable Isotopic Composition, And Export Fluxes Of Doc, Poc, And Dic From The Lower Mississippi River During 2006-2008, Yihua Cai, Laodong Guo, Xuri Wang, George Aiken Nov 2015

Abundance, Stable Isotopic Composition, And Export Fluxes Of Doc, Poc, And Dic From The Lower Mississippi River During 2006-2008, Yihua Cai, Laodong Guo, Xuri Wang, George Aiken

Faculty Publications

Sources, abundance, isotopic compositions, and export fluxes of dissolved inorganic carbon (DIC), dissolved and colloidal organic carbon (DOC and COC), and particulate organic carbon (POC), and their response to hydrologic regimes were examined through monthly sampling from the Lower Mississippi River during 2006–2008. DIC was the most abundant carbon species, followed by POC and DOC. Concentration and δ13C of DIC decreased with increasing river discharge, while those of DOC remained fairly stable. COC comprised 61 ± 3% of the bulk DOC with similar δ13C abundances but higher percentages of hydrophobic organic acids than DOC, suggesting its …


Hornbrook Formation, Oregon And California: A Sedimentary Record Of The Late Cretaceous Sierran Magmatic Flare-Up Event, Kathleen D. Surpless Nov 2015

Hornbrook Formation, Oregon And California: A Sedimentary Record Of The Late Cretaceous Sierran Magmatic Flare-Up Event, Kathleen D. Surpless

Geosciences Faculty Research

Early Late Cretaceous time was characterized by a major magmatic flare-up event in the Sierra Nevada batholith and early phases of magmatism in the Idaho batholith, but the sedimentary record of this voluminous magmatism in the U.S. Cordillera is considerably less conspicuous. New detrital zircon U-Pb ages from the Hornbrook Formation in southern Oregon and northern California reveal a significant and sustained influx of 100–85 Ma detrital zircons into the broader Hornbrook region beginning ca. 90 Ma. Detrital zircon ages and hafnium isotopic compositions, combined with whole-rock geochemistry, suggest that sediment was largely derived from the Sierra Nevada, requiring uplift …


Alternating Direction Implicit Method With Adaptive Grids For Modeling Chemotaxis In Dictyostelium Discoideum, Christopher F. Loomis Nov 2015

Alternating Direction Implicit Method With Adaptive Grids For Modeling Chemotaxis In Dictyostelium Discoideum, Christopher F. Loomis

Theses and Dissertations

Dictyostelium discoideum (Dd) is a model organism, studied for reasons from cell movement to chemotaxis to human disease control. Creating a computer model of the life cycle of Dd has garnered great interest, one part of which is the Aggregation Stage, where thousands of amoeba gather together to form a slug. Chemotaxis is the mechanism through which this is accomplished. This thesis develops two- and three-dimensional alternating direction implicit code which solves the diffusion equation on an adaptive grid. The calculated values for both two and three dimensions are checked against the actual solution and error results are provided. Comparisons …


Powerforecaster: Predicting Smartphone Power Impact Of Continuous Sensing Applications At Pre-Installation Time, Chulhong Min, Youngki Lee, Chungkuk Yoo, Seungwoo Kang, Sangwon Choi, Pillsoon Park, Inseok Hwang, Younghyun Ju, Seungpyo Choi, Junehwa Song Nov 2015

Powerforecaster: Predicting Smartphone Power Impact Of Continuous Sensing Applications At Pre-Installation Time, Chulhong Min, Youngki Lee, Chungkuk Yoo, Seungwoo Kang, Sangwon Choi, Pillsoon Park, Inseok Hwang, Younghyun Ju, Seungpyo Choi, Junehwa Song

Research Collection School Of Computing and Information Systems

Today's smartphone application (hereinafter 'app') markets miss a key piece of information, power consumption of apps. This causes a severe problem for continuous sensing apps as they consume significant power without users' awareness. Users have no choice but to repeatedly install one app after another and experience their power use. To break such an exhaustive cycle, we propose PowerForecaster, a system that provides users with power use of sensing apps at pre-installation time. Such advanced power estimation is extremely challenging since the power cost of a sensing app largely varies with users' physical activities and phone use patterns. We observe …


Event Detection In Wireless Sensor Networks In Random Spatial Sensors Deployments, Pengfei Zhang, Ido Nevat, Gareth W. Peters, Gaoxi Xiao, Hwee-Pink Tan Nov 2015

Event Detection In Wireless Sensor Networks In Random Spatial Sensors Deployments, Pengfei Zhang, Ido Nevat, Gareth W. Peters, Gaoxi Xiao, Hwee-Pink Tan

Research Collection School Of Computing and Information Systems

We develop a new class of event detection algorithms in Wireless Sensor Networks where the sensors are randomly deployed spatially. We formulate the detection problem as a binary hypothesis testing problem and design the optimal decision rules for two scenarios, namely the Poisson Point Process and Binomial Point Process random deployments. To calculate the intractable marginal likelihood density, we develop three types of series expansion methods which are based on an Askey-orthogonal polynomials. In addition, we develop a novel framework to provide guidance on which series expansion is most suitable (i.e., most accurate) to use for different system parameters. Extensive …


Iowa Waste Reduction Center Newsletter, November 2015, University Of Northern Iowa. Iowa Waste Reduction Center. Nov 2015

Iowa Waste Reduction Center Newsletter, November 2015, University Of Northern Iowa. Iowa Waste Reduction Center.

Iowa Waste Reduction Center Newsletter

Inside this Issue:

--- IWRC Takes Food Waste Reduction International
--- New Food Waste Project Underway
--- Bolick Named to 20 Under 40 List
--- Video of the Month
--- Industry News


Searches For Continuous Gravitational Waves From Nine Young Supernova Remnants, J. Aasi, B. P. Abbott, R. Abbott, T. Abbott, M. R. Abernathy, F. Acernese, K. Ackley, C. Adams, T. Adams, P. Addesso, R. X. Adhikari, V. Adya, C. Affeldt, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, A. Ain, P. Ajith, A. Alemic, B. Allen, A. Allocca, D. Amariutei, S. B. Anderson, W. G. Anderson, K. Arai, M. C. Araya, C. Arceneaux, J. S. Areeda, S. Ast Nov 2015

Searches For Continuous Gravitational Waves From Nine Young Supernova Remnants, J. Aasi, B. P. Abbott, R. Abbott, T. Abbott, M. R. Abernathy, F. Acernese, K. Ackley, C. Adams, T. Adams, P. Addesso, R. X. Adhikari, V. Adya, C. Affeldt, M. Agathos, K. Agatsuma, N. Aggarwal, O. D. Aguiar, A. Ain, P. Ajith, A. Alemic, B. Allen, A. Allocca, D. Amariutei, S. B. Anderson, W. G. Anderson, K. Arai, M. C. Araya, C. Arceneaux, J. S. Areeda, S. Ast

Physics and Astronomy Faculty Publications and Presentations

We describe directed searches for continuous gravitational waves (GWs) in data from the sixth Laser Interferometer Gravitational-wave Observatory (LIGO) science data run. The targets were nine young supernova remnants not associated with pulsars; eight of the remnants are associated with non-pulsing suspected neutron stars. One target's parameters are uncertain enough to warrant two searches, for a total of 10. Each search covered a broad band of frequencies and first and second frequency derivatives for a fixed sky direction. The searches coherently integrated data from the two LIGO interferometers over time spans from 5.3-25.3 days using the matched-filtering -statistic. We found …


Interpolation Guided Compositional Verification, Shang-Wei Lin, Jun Sun, Truong Khanh Nguyen, Yang Liu, Jin Song Dong Nov 2015

Interpolation Guided Compositional Verification, Shang-Wei Lin, Jun Sun, Truong Khanh Nguyen, Yang Liu, Jin Song Dong

Research Collection School Of Computing and Information Systems

Model checking suffers from the state space explosion problem. Compositional verification techniques such as assume-guarantee reasoning (AGR) have been proposed to alleviate the problem. However, there are at least three challenges in applying AGR. Firstly, given a system M1 M2, how do we automatically construct and refine (in the presence of spurious counterexamples) an assumption A2, which must be an abstraction of M2? Previous approaches suggest to incrementally learn and modify the assumption through multiple invocations of a model checker, which could be often time consuming. Secondly, how do we keep the state space small when checking M1 A2 |= …


Challenges In Analyzing Software Documentation In Portuguese, Christoph Treude, Carlos A. Prolo, Fernando Figueira Filho Nov 2015

Challenges In Analyzing Software Documentation In Portuguese, Christoph Treude, Carlos A. Prolo, Fernando Figueira Filho

Research Collection School Of Computing and Information Systems

Many tools that automatically analyze, summarize, or transform software artifacts rely on natural language processing tooling for the interpretation of natural language text produced by software developers, such as documentation, code comments, commit messages, or bug reports. Processing natural language text produced by software developers is challenging because of unique characteristics not found in other texts, such as the presence of code terms and the systematic use of incomplete sentences. In addition, texts produced by Portuguese-speaking developers mix languages since many keywords and programming concepts are referred to by their English name. In this paper, we provide empirical insights into …


Human Action Recognition In Unconstrained Videos By Explicit Motion Modeling, Yu-Gang Jiang, Qi Dai, Wei Liu, Xiangyang Xue, Chong-Wah Ngo Nov 2015

Human Action Recognition In Unconstrained Videos By Explicit Motion Modeling, Yu-Gang Jiang, Qi Dai, Wei Liu, Xiangyang Xue, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

Human action recognition in unconstrained videos is a challenging problem with many applications. Most state-of-the-art approaches adopted the well-known bag-of-features representations, generated based on isolated local patches or patch trajectories, where motion patterns, such as object-object and object-background relationships are mostly discarded. In this paper, we propose a simple representation aiming at modeling these motion relationships. We adopt global and local reference points to explicitly characterize motion information, so that the final representation is more robust to camera movements, which widely exist in unconstrained videos. Our approach operates on the top of visual codewords generated on dense local patch trajectories, …


Direct Or Indirect Match? Selecting Right Concepts For Zero-Example Case, Yi-Jie Lu, Maaike De Boer, Hao Zhang, Klamer Schutte, Wessel Kraaij, Chong-Wah Ngo Nov 2015

Direct Or Indirect Match? Selecting Right Concepts For Zero-Example Case, Yi-Jie Lu, Maaike De Boer, Hao Zhang, Klamer Schutte, Wessel Kraaij, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

No abstract provided.


Codehow: Effective Code Search Based On Api Understanding And Extended Boolean Model (E), Fei Lv, Jian-Guang Lou, Shaowei Wang, Dongmei Zhang, Jainjun Zhao Nov 2015

Codehow: Effective Code Search Based On Api Understanding And Extended Boolean Model (E), Fei Lv, Jian-Guang Lou, Shaowei Wang, Dongmei Zhang, Jainjun Zhao

Research Collection School Of Computing and Information Systems

Over the years of software development, a vast amount of source code has been accumulated. Many code search tools were proposed to help programmers reuse previously-written code by performing free-text queries over a large-scale codebase. Our experience shows that the accuracy of these code search tools are often unsatisfactory. One major reason is that existing tools lack of query understanding ability. In this paper, we propose CodeHow, a code search technique that can recognize potential APIs a user query refers to. Having understood the potentially relevant APIs, CodeHow expands the query with the APIs and performs code retrieval by applying …


Cost-Sensitive Online Classification With Adaptive Regularization And Its Applications, Peilin Zhao, Furen Zhuang, Min Wu, Xiao-Li Li, Hoi, Steven C. H. Nov 2015

Cost-Sensitive Online Classification With Adaptive Regularization And Its Applications, Peilin Zhao, Furen Zhuang, Min Wu, Xiao-Li Li, Hoi, Steven C. H.

Research Collection School Of Computing and Information Systems

Cost-Sensitive Online Classification is recently proposed to directly online optimize two well-known cost-sensitive measures: (i) maximization of weighted sum of sensitivity and specificity, and (ii) minimization of weighted misclassification cost. However, the previous existing learning algorithms only utilized the first order information of the data stream. This is insufficient, as recent studies have proved that incorporating second order information could yield significant improvements on the prediction model. Hence, we propose a novel cost-sensitive online classification algorithm with adaptive regularization. We theoretically analyzed the proposed algorithm and empirically validated its effectiveness with extensive experiments. We also demonstrate the application of the …


Dictionary Pair Learning On Grassmann Manifolds For Image Denoising, Xianhua Zeng, Wei Bian, Wei Liu, Jialie Shen, Dacheng Tao Nov 2015

Dictionary Pair Learning On Grassmann Manifolds For Image Denoising, Xianhua Zeng, Wei Bian, Wei Liu, Jialie Shen, Dacheng Tao

Research Collection School Of Computing and Information Systems

Image denoising is a fundamental problem in computer vision and image processing that holds considerable practical importance for real-world applications. The traditional patch-based and sparse coding-driven image denoising methods convert 2D image patches into 1D vectors for further processing. Thus, these methods inevitably break down the inherent 2D geometric structure of natural images. To overcome this limitation pertaining to the previous image denoising methods, we propose a 2D image denoising model, namely, the dictionary pair learning (DPL) model, and we design a corresponding algorithm called the DPL on the Grassmann-manifold (DPLG) algorithm. The DPLG algorithm first learns an initial dictionary …


Where Are The Passengers? A Grid-Based Gaussian Mixture Model For Taxi Bookings, Meng-Fen Chiang, Tuan Anh Hoang, Ee-Peng Lim Nov 2015

Where Are The Passengers? A Grid-Based Gaussian Mixture Model For Taxi Bookings, Meng-Fen Chiang, Tuan Anh Hoang, Ee-Peng Lim

Research Collection School Of Computing and Information Systems

Taxi bookings are events where requests for taxis are made by passengers either over voice calls or mobile apps. As the demand for taxis changes with space and time, it is important to model both the space and temporal dimensions in dynamic booking data. Several applications can benefit from a good taxi booking model. These include the prediction of number of bookings at certain location and time of the day, and the detection of anomalous booking events. In this paper, we propose a Grid-based Gaussian Mixture Model (GGMM) with spatio-temporal dimensions that groups booking data into a number of spatio-temporal …