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Merged Aggregate Nearest Neighbor Query Processing In Road Networks, Weiwei Sun, Chong Chen, Baihua Zheng, Chunan Chen, Liang Zhu Oct 2013

Merged Aggregate Nearest Neighbor Query Processing In Road Networks, Weiwei Sun, Chong Chen, Baihua Zheng, Chunan Chen, Liang Zhu

Research Collection School Of Computing and Information Systems

Aggregate nearest neighbor query, which returns a common interesting point that minimizes the aggregate distance for a given query point set, is one of the most important operations in spatial databases and their application domains. This paper addresses the problem of finding the aggregate nearest neighbor for a merged set that consists of the given query point set and multiple points needed to be selected from a candidate set, which we name as merged aggregate nearest neighbor(MANN) query. This paper proposes an effective algorithm to process MANN query in road networks based on our pruning strategies. Extensive experiments are conducted …

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On Effects Of Visual Query Complexity, Jialie Shen, Cheng Zhiyong Oct 2013

On Effects Of Visual Query Complexity, Jialie Shen, Cheng Zhiyong

Research Collection School Of Computing and Information Systems

As an effective technique to manage large scale image collections, content-based image retrieval (CBIR) has been received great attentions and became a very active research domain in recent years. While assessing system performance is one of the key factors for the related technological advancement, relatively little attention has been paid to model and analyze test queries. This paper documents a study on the problem of determining visual query complexity as a measure for predicting image retrieval performance. We propose a quantitative metric for measuring complexity of image queries for content-based image search engine. A set of experiments are carried out …

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Creating Adaptive Quests To Support Personalized Learning Experiences When Learning Software Languages, Chris Boesch, Sandra Boesch Oct 2013

Creating Adaptive Quests To Support Personalized Learning Experiences When Learning Software Languages, Chris Boesch, Sandra Boesch

Research Collection School Of Computing and Information Systems

Over the past three years the authors have been developing and refining an online practicing platform called SingPath, which enables users to practice writing code in various software languages. The most recent feature to be released is a Quest mode that encourages users by showing short video clips each time a user solves five problems. In addition, users are able to choose whether to play through these quests on easy, medium, or hard levels of difficulty. The ability for users to customize their game play enables them to modify the difficulty of the experience and ideally self-regulate how frustrating or …

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Learning Topics And Positions From Debatepedia, Swapna Gottopati, Minghui Qiu, Yanchuan Sim, Jing Jiang, Noah Smith Oct 2013

Learning Topics And Positions From Debatepedia, Swapna Gottopati, Minghui Qiu, Yanchuan Sim, Jing Jiang, Noah Smith

Research Collection School Of Computing and Information Systems

We explore Debatepedia, a communityauthored encyclopedia of sociopolitical debates, as evidence for inferring a lowdimensional, human-interpretable representation in the domain of issues and positions. We introduce a generative model positing latent topics and cross-cutting positions that gives special treatment to person mentions and opinion words. We evaluate the resulting representation’s usefulness in attaching opinionated documents to arguments and its consistency with human judgments about positions.

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Modeling Interaction Features For Debate Side Clustering, Minghui Qiu, Liu Yang, Jing Jiang Oct 2013

Modeling Interaction Features For Debate Side Clustering, Minghui Qiu, Liu Yang, Jing Jiang

Research Collection School Of Computing and Information Systems

Online discussion forums are popular social media platforms for users to express their opinions and discuss controversial issues with each other. To automatically identify the sides/stances of posts or users from textual content in forums is an important task to help mine online opinions. To tackle the task, it is important to exploit user posts that implicitly contain support and dispute (interaction) information. The challenge we face is how to mine such interaction information from the content of posts and how to use them to help identify stances. This paper proposes a two-stage solution based on latent variable models: an …

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Predictive Handling Of Asynchronous Concept Drifts In Distributed Environments, Hock Hee Ang, Vivek Gopalkrishnan, Indre Zliobaite, Mykola Pechenizkiy, Steven C. H. Hoi Oct 2013

Predictive Handling Of Asynchronous Concept Drifts In Distributed Environments, Hock Hee Ang, Vivek Gopalkrishnan, Indre Zliobaite, Mykola Pechenizkiy, Steven C. H. Hoi

Research Collection School Of Computing and Information Systems

In a distributed computing environment, peers collaboratively learn to classify concepts of interest from each other. When external changes happen and their concepts drift, the peers should adapt to avoid increase in misclassification errors. The problem of adaptation becomes more difficult when the changes are asynchronous, i.e., when peers experience drifts at different times. We address this problem by developing an ensemble approach, PINE, that combines reactive adaptation via drift detection, and proactive handling of upcoming changes via early warning and adaptation across the peers. With empirical study on simulated and real-world data sets, we show that PINE handles asynchronous …

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Skyhunter: A Multi-Surface Environment For Supporting Oil And Gas Exploration, Teddy Seyed, Mario Costa Sousa, Frank Maurer, Anthony Tang Oct 2013

Skyhunter: A Multi-Surface Environment For Supporting Oil And Gas Exploration, Teddy Seyed, Mario Costa Sousa, Frank Maurer, Anthony Tang

Research Collection School Of Computing and Information Systems

The process of oil and gas exploration and its result, the decision to drill for oil in a specific location, relies on a number of distinct but related domains. These domains require effective collaboration to come to a decision that is both cost effective and maintains the integrity of the environment. As we show in this paper, many of the existing technologies and practices that support the oil and gas exploration process overlook fundamental user issues such as collaboration, interaction and visualization. The work presented in this paper is based upon a design process that involved expert users from an …

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Image Search By Graph-Based Label Propagation With Image Representation From Dnn, Yingwei Pan, Yao Ting, Kuiyuan Yang, Houqiang Li, Chong-Wah Ngo, Jingdong Wang, Tao Mei Oct 2013

Image Search By Graph-Based Label Propagation With Image Representation From Dnn, Yingwei Pan, Yao Ting, Kuiyuan Yang, Houqiang Li, Chong-Wah Ngo, Jingdong Wang, Tao Mei

Research Collection School Of Computing and Information Systems

Our objective is to estimate the relevance of an image to a query for image search purposes. We address two limitations of the existing image search engines in this paper. First, there is no straightforward way of bridging the gap between semantic textual queries as well as users’ search intents and image visual content. Image search engines therefore primarily rely on static and textual features. Visual features are mainly used to identify potentially useful recurrent patterns or relevant training examples for complementing search by image reranking. Second, image rankers are trained on query-image pairs labeled by human experts, making the …

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Understanding Online Consumer’S Inter-Purchase Time, Youngsoo Kim Oct 2013

Understanding Online Consumer’S Inter-Purchase Time, Youngsoo Kim

Research Collection School Of Computing and Information Systems

This study is motivated by the premise that online consumers can make a purchase at any time of day if they have even a tiny time slot along with Internet access. Given the increased shopping time flexibility, we first examine the patterns of online purchase timing at an online shopping mall handling diverse products (e.g., Amazon.com). The results show (1) the breakdown of purchase timing regularity and (2) the change of weekly spike purchase occurrence. Second, we build online inter-purchase time and price promotion utilization models and estimate them with the data collected from one of the premier online shopping …

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Adaptive Gameplay For Programming Practice, Chris Boesch, Sandra Boesch Oct 2013

Adaptive Gameplay For Programming Practice, Chris Boesch, Sandra Boesch

Research Collection School Of Computing and Information Systems

Over the past four years, we have collaborated to develop a set of online games to enable users to practice software languages in a self-directed manner and as part of a class. Recently we introduced a new adaptive difficulty feature that enables players to self-regulate the difficulty of the games they are playing to practice. These new features also provide additional information to further adapt the problem content to better meet the needs of the users.

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Consistent Stereo Image Editing, Tao Yan, Shengfeng He, Rynson W.H. Lau, Yun Xu Oct 2013

Consistent Stereo Image Editing, Tao Yan, Shengfeng He, Rynson W.H. Lau, Yun Xu

Research Collection School Of Computing and Information Systems

Stereo images and videos are very popular in recent years, and techniques for processing this media are attracting a lot of attention. In this paper, we extend the shift-map method for stereo image editing. Our method simultaneously processes the left and right images on pixel level using a global optimization algorithm. It enforces photo consistence between the two images and preserves 3D scene structures. It also addresses the occlusion and disocclusion problem, which may enable many stereo image editing functions, such as depth mapping, object depth adjustment and non-homogeneous image resizing. Our experiments show that the proposed method produces high …

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The Vireo Team At Mediaeval 2013: Violent Scenes Detection By Mid-Level Concepts Learnt From Youtube, Chun Chet Tan, Chong-Wah Ngo Oct 2013

The Vireo Team At Mediaeval 2013: Violent Scenes Detection By Mid-Level Concepts Learnt From Youtube, Chun Chet Tan, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

The Violent Scenes Detection task continues to pose challenge in detecting violent scenes in Hollywood movies. In this working notes paper, we present the framework of our system and briefly discuss the performance results obtained in both objective and subjective subtasks. Besides using the low-level features for training the SVM classifiers for violent scenes detection, we show the feasibility in using the concept detectors to infer the occurrence of violent scenes. External Youtube data is exploited in our implementation to provide more diverse definition to violent scene concepts. Furthermore, we explore the feasibility of using Conditional Random Fields (CRF) to …

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Accurate Developer Recommendation For Bug Resolution, Xin Xia, David Lo, Xinyu Wang, Bo Zhou Oct 2013

Accurate Developer Recommendation For Bug Resolution, Xin Xia, David Lo, Xinyu Wang, Bo Zhou

Research Collection School Of Computing and Information Systems

Bug resolution refers to the activity that developers perform to diagnose, fix, test, and document bugs during software development and maintenance. It is a collaborative activity among developers who contribute their knowledge, ideas, and expertise to resolve bugs. Given a bug report, we would like to recommend the set of bug resolvers that could potentially contribute their knowledge to fix it. We refer to this problem as developer recommendation for bug resolution. In this paper, we propose a new and accurate method named DevRec for the developer recommendation problem. DevRec is a composite method which performs two kinds of analysis: …

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A Collusion-Resistant Conditional Access System For Flexible-Pay-Per-Channel Pay-Tv Broadcasting, Zhiguo Wan, June Liu, Rui Zhang, Robert H. Deng Oct 2013

A Collusion-Resistant Conditional Access System For Flexible-Pay-Per-Channel Pay-Tv Broadcasting, Zhiguo Wan, June Liu, Rui Zhang, Robert H. Deng

Research Collection School Of Computing and Information Systems

Pay-TV Broadcasting system, an extensively de- ployed application, charges its subscribers when receiving the broadcasted video. A conditional access system (CAS) ensures security for the Pay-TV broadcasting system, which is designed to control TV channel/program access to only authorized subscribers. There are mainly three CAS models: pay-per-channel (PPC), pay-per-view (PPV), and flexible-pay-per-channel (F- PPC). F-PPC is a novel model which combines the properties and advantages of both PPC and PPV. Several key management schemes with four-level hierarchical key structure have been proposed for this model. In this paper, we point out a severe security weakness of these schemes against collusion …

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Annotation For Free: Video Tagging By Mining User Search Behavior, Yao Ting, Tao Mei, Chong-Wah Ngo, Shipeng Li Oct 2013

Annotation For Free: Video Tagging By Mining User Search Behavior, Yao Ting, Tao Mei, Chong-Wah Ngo, Shipeng Li

Research Collection School Of Computing and Information Systems

The problem of tagging is mostly considered from the perspectives of machine learning and data-driven philosophy. A fundamental issue that underlies the success of these approaches is the visual similarity, ranging from the nearest neighbor search to manifold learning, to identify similar instances of an example for tag completion. The need to searching for millions of visual examples in high-dimensional feature space, however, makes the task computationally expensive. Moreover, the results can suffer from robustness problem, when the underlying data, such as online videos, are rich of semantics and the similarity is difficult to be learnt from low-level features. This …

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Error Recovered Hierarchical Classification, Shiai Zhu, Xiao-Yong Wei, Chong-Wah Ngo Oct 2013

Error Recovered Hierarchical Classification, Shiai Zhu, Xiao-Yong Wei, Chong-Wah Ngo

Research Collection School Of Computing and Information Systems

Hierarchical classification (HC) is a popular and efficient way for detecting the semantic concepts from the images. However, the conventional HC, which always selects the branch with the highest classification response to go on, has the risk of propagating serious errors from higher levels of the hierarchy to the lower levels. We argue that the highestresponse-first strategy is too arbitrary, because the candidate nodes are considered individually which ignores the semantic relationship among them. In this paper, we propose a novel method for HC, which is able to utilize the semantic relationship among candidate nodes and their children to recover …

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K-Time Proxy Signature: Formal Definition And Efficient Construction, Weiwei Liu, Guomin Yang, Yi Mu, Jiannan Wei Oct 2013

K-Time Proxy Signature: Formal Definition And Efficient Construction, Weiwei Liu, Guomin Yang, Yi Mu, Jiannan Wei

Research Collection School Of Computing and Information Systems

Proxy signature, which allows an original signer to delegate his/her signing right to another party (or proxy signer), is very useful in many applications. Conventional proxy signature only allows the original signer to specify in the warrant the validity time period of the delegation but not the number of proxy signatures the proxy signer can generate. To address this problem, in this paper, we provide a formal treatment for k-time proxy signature. Such a scheme allows a designated proxy signer to produce only a fixed number of proxy signatures on behalf of the original signer. We provide the formal definitions …

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An Experimental Study For Inter-User Interference Mitigation In Wireless Body Sensor Networks, Bin Cao, Yu Ge, Chee Wee Kim, Gang Feng, Hwee-Pink Tan, Yun Li Oct 2013

An Experimental Study For Inter-User Interference Mitigation In Wireless Body Sensor Networks, Bin Cao, Yu Ge, Chee Wee Kim, Gang Feng, Hwee-Pink Tan, Yun Li

Research Collection School Of Computing and Information Systems

Inter-user interference degrades the reliability of data delivery in wireless body sensor networks (WBSNs) in dense deployments when multiple users wearing WBSNs are in close proximity to one another. The impact of such interference in realistic WBSN systems is significant but is not well explored. To this end, we investigate and analyze the impact of inter-user interference on packet delivery ratio (PDR) and throughput. We conduct extensive experiments based on the TelosB WBSN platform, considering unslotted carrier sense multiple access (CSMA) with collision avoidance (CA) and slotted CSMA/CA modes in IEEE 802.15.4 MAC, respectively. In order to mitigate interuser interference, …

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Todmis: Mining Communities From Trajectories, Siyuan Liu, Shuhui Wang, Kasthuri Jayarajah, Archan Misra, Rammaya Krishnan Oct 2013

Todmis: Mining Communities From Trajectories, Siyuan Liu, Shuhui Wang, Kasthuri Jayarajah, Archan Misra, Rammaya Krishnan

Research Collection School Of Computing and Information Systems

Existing algorithms for trajectory-based clustering usually rely on simplex representation and a single proximity-related distance (or similarity) measure. Consequently, additional information markers (e.g., social interactions or the semantics of the spatial layout) are usually ignored, leading to the inability to fully discover the communities in the trajectory database. This is especially true for human-generated trajectories, where additional fine-grained markers (e.g., movement velocity at certain locations, or the sequence of semantic spaces visited) can help capture latent relationships between cluster members. To address this limitation, we propose TODMIS: a general framework for Trajectory cOmmunity Discovery using Multiple Information Sources. TODMIS combines …

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Automatic Recovery Of Root Causes From Bug-Fixing Changes, Ferdian Thung, David Lo, Lingxiao Jiang Oct 2013

Automatic Recovery Of Root Causes From Bug-Fixing Changes, Ferdian Thung, David Lo, Lingxiao Jiang

Research Collection School Of Computing and Information Systems

No abstract provided.

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A Unified Model For Topics, Events And Users On Twitter, Qiming Diao, Jing Jiang Oct 2013

A Unified Model For Topics, Events And Users On Twitter, Qiming Diao, Jing Jiang

Research Collection School Of Computing and Information Systems

With the rapid growth of social media, Twitter has become one of the most widely adopted platforms for people to post short and instant message. On the one hand, people tweets about their daily lives, and on the other hand, when major events happen, people also follow and tweet about them. Moreover, people’s posting behaviors on events are often closely tied to their personal interests. In this paper, we try to model topics, events and users on Twitter in a unified way. We propose a model which combines an LDA-like topic model and the Recurrent Chinese Restaurant Process to capture …

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Livelabs: Initial Reflections On Building A Large-Scale Mobile Behavioral Experimentation Testbed, Archan Misra, Rajesh Krishna Balan Oct 2013

Livelabs: Initial Reflections On Building A Large-Scale Mobile Behavioral Experimentation Testbed, Archan Misra, Rajesh Krishna Balan

Research Collection School Of Computing and Information Systems

We believe that, for successful adoption of novel mobile technologies and applications, it is important to be able to test them under real usage patterns, and with real users. To implement this vision, we present our initial effort in building LiveLabs, a large-scale mobile testbed for in-situ experimentation. LiveLabs is unique in two aspects. First, LiveLabs operates on a scale much larger than most research testbeds— it is being deployed in four different public spaces in Singapore (a university campus, a shopping mall, an airport and a leisure resort), and is expected to have a pool of over 30,000 opt-in …

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The Myths Of G-Tech For Business Decision Making, Tin Seong Kam Sep 2013

The Myths Of G-Tech For Business Decision Making, Tin Seong Kam

Research Collection School Of Computing and Information Systems

More than 80% of organisation data are location related - the locations where transactions are done, where retailers are found, and of customers who buy their products. Since the early 2005, there has been an increasing interest among the business community to use geospatial technology to enhance decision making process at both strategic and operational levels. Millions of dollars and man-hours have been invested into driving their geo-technology development and implementation. The use of geospatial technology in business, however, tends to confine to simple mapping. Many of these failures are the victims of misperception. Some of the perpetrators are practitioners. …

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Riga: A Rich Internet Geospatial Analytics Application For Area-Based Data, Tin Seong Kam Sep 2013

Riga: A Rich Internet Geospatial Analytics Application For Area-Based Data, Tin Seong Kam

Research Collection School Of Computing and Information Systems

In this information age, more and more public statistical data such as population census, household living, local economy and business establishment are distributed over the internet within the framework of spatial data infrastructure. By and large, these data are organized geographically such as region, province as well as district. Usually, they are published in the form of digital maps over the internet as simple points, lines and polygons markers limited or no analytical function available to transform these data into useful information. To meet the analytical needs of casual public data users, we contribute RIGA, a rich internet geospatial analytics …

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Transforming Finance For The Future, Siu Loon Hoe Sep 2013

Transforming Finance For The Future, Siu Loon Hoe

Research Collection School Of Computing and Information Systems

Significant changes in external market conditions have resulted in operations placing greater demands on the finance function. Traditional finance departments are increasingly expected to deliver more value and be more proactive in supporting the organization's overall business strategies. Unfortunately, many finance departments are not yet ready to meet such challenges. This article proposes a transformation process to reorganize present day finance functions to become a finance of the future. The proposed process applies tools such as best practices, outsourcing and technology to achieve a desired future outcome.

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Will Fault Localization Work For These Failures? An Automated Approach To Predict Effectiveness Of Fault Localization Tools, Tien-Duy B. Le, David Lo Sep 2013

Will Fault Localization Work For These Failures? An Automated Approach To Predict Effectiveness Of Fault Localization Tools, Tien-Duy B. Le, David Lo

Research Collection School Of Computing and Information Systems

Debugging is a crucial yet expensive activity to improve the reliability of software systems. To reduce debugging cost, various fault localization tools have been proposed. A spectrum-based fault localization tool often outputs an ordered list of program elements sorted based on their likelihood to be the root cause of a set of failures (i.e., their suspiciousness scores). Despite the many studies on fault localization, unfortunately, however, for many bugs, the root causes are often low in the ordered list. This potentially causes developers to distrust fault localization tools. Recently, Parnin and Orso highlight in their user study that many debuggers …

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Learning Spatio-Temporal Co-Occurrence Correlograms For Efficient Human Action Classification, Qianru Sun, Hong Liu Sep 2013

Learning Spatio-Temporal Co-Occurrence Correlograms For Efficient Human Action Classification, Qianru Sun, Hong Liu

Research Collection School Of Computing and Information Systems

Spatio-temporal interest point (STIP) based features show great promises in human action analysis with high efficiency and robustness. However, they typically focus on bag-of-visual words (BoVW), which omits any correlation among words and shows limited discrimination in real-world videos. In this paper, we propose a novel approach to add the spatio-temporal co-occurrence relationships of visual words to BoVW for a richer representation. Rather than assigning a particular scale on videos, we adopt the normalized google-like distance (NGLD) to measure the words' co-occurrence semantics, which grasps the videos' structure information in a statistical way. All pairwise distances in spatial and temporal …

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Driverguard: Virtualization Based Fine-Grained Protection On I/O Flows, Yueqiang Cheng, Xuhua Ding, Robert H. Deng Sep 2013

Driverguard: Virtualization Based Fine-Grained Protection On I/O Flows, Yueqiang Cheng, Xuhua Ding, Robert H. Deng

Research Collection School Of Computing and Information Systems

Most commodity peripheral devices and their drivers are geared to achieve high performance with security functions being opted out. The absence of strong security measures invites attacks on the I/O data and consequently posts threats to those services feeding on them, such as fingerprint-based biometric authentication. In this article, we present a generic solution called DriverGuard, which dynamically protects the secrecy of I/O flows such that the I/O data are not exposed to the malicious kernel. Our design leverages a composite of cryptographic and virtualization techniques to achieve fine-grained protection without using any extra devices and modifications on user applications. …

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An Analysis Of Post-Selection In Automatic Configuration, Zhi Yuan, Thomas St\303\274tzle, Marco A. Montes De Oca, Hoong Chuin Lau, Mauro Birattari Sep 2013

An Analysis Of Post-Selection In Automatic Configuration, Zhi Yuan, Thomas St\303\274tzle, Marco A. Montes De Oca, Hoong Chuin Lau, Mauro Birattari

Research Collection School Of Computing and Information Systems

Automated algorithm configuration methods have proven to be instrumental in deriving high-performing algorithms and such methods are increasingly often used to configure evolutionary algorithms. One major challenge in devising automatic algorithm configuration techniques is to handle the inherent stochasticity in the configuration problems. This article analyses a post-selection mechanism that can also be used for this task. The central idea of the post-selection mechanism is to generate in a first phase a set of high-quality candidate algorithm configurations and then to select in a second phase from this candidate set the (statistically) best configuration. Our analysis of this mechanism indicates …

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Inferring Ongoing Human Activities Based On Recurrent Self-Organizing Map Trajectory, Qianru Sun, Hong Liu Sep 2013

Inferring Ongoing Human Activities Based On Recurrent Self-Organizing Map Trajectory, Qianru Sun, Hong Liu

Research Collection School Of Computing and Information Systems

Automatically inferring ongoing activities is to enable the early recognition of unfinished activities, which is quite meaningful for applications, such as online human-machine interaction and security monitoring. State-of-the-art methods use the spatiotemporal interest point (STIP) based features as the low-level video description to handle complex scenes. While the existing problem is that typical bag-of-visual words (BoVW) focuses on the statistical distribution of features but ignores the inherent contexts in activity sequences, resulting in low discrimination when directly dealing with limited observations. To solve this problem, the Recurrent Self-Organizing Map (RSOM), which was designed to process sequential data, is novelly adopted …

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