Anomalous event detection using a semi-two dimensional hidden Markov model

The rapid increase in the deployment of CCTV systems has led to a greater demand for algorithms that are able to process incoming video feeds. These algorithms are designed to extract information of interest for human operators. During the past several years, there has been a large effort to detect abnormal activities through computer vision techniques. Typically, the problem is formulated as a novelty detection task where the system is trained on normal data and is required to detect events which do not fit the learned `normal' model. Many researchers have tried various sets of features to train different learning models to detect abnormal behaviour in video footage. In this work we propose using a Semi-2D Hidden Markov Model (HMM) to model the normal activities of people. The outliers of the model with insufficient likelihood are identified as abnormal activities. Our Semi-2D HMM is designed to model both the temporal and spatial causalities of the crowd behaviour by assuming the current state of the Hidden Markov Model depends not only on the previous state in the temporal direction, but also on the previous states of the adjacent spatial locations. Two different HMMs are trained to model both the vertical and horizontal spatial causal information. Location features, flow features and optical flow textures are used as the features for the model. The proposed approach is evaluated using the publicly available UCSD datasets and we demonstrate improved performance compared to other state of the art methods.

Civil Procedure : Commentary and Materials (5th ed.)

This book provides a comprehensive analysis of the practical and theoretical issues encountered in Australian civil procedure, including alternative dispute resolution. Each chapter features in-depth questions and notes together with lists of further reading to aid understanding of the issue. It also examines and discusses each substantive and procedural step in the trial process. Topics include jurisdiction of a court to consider a matter, alternative dispute resolution. limitations of actions, commencing proceedings, pleading, gathering evidence, trial and appeal, costs and practice directions. Each of the state, territory and federal procedures is covered.

A Comprehensive Benchmarking Framework (CoBeFra) for conformance analysis between procedural process models and event logs in ProM

Process mining encompasses the research area which is concerned with knowledge discovery from information system event logs. Within the process mining research area, two prominent tasks can be discerned. First of all, process discovery deals with the automatic construction of a process model out of an event log. Secondly, conformance checking focuses on the assessment of the quality of a discovered or designed process model in respect to the actual behavior as captured in event logs. Hereto, multiple techniques and metrics have been developed and described in the literature. However, the process mining domain still lacks a comprehensive framework for assessing the goodness of a process model from a quantitative perspective. In this study, we describe the architecture of an extensible framework within ProM, allowing for the consistent, comparative and repeatable calculation of conformance metrics. For the development and assessment of both process discovery as well as conformance techniques, such a framework is considered greatly valuable.

How activation, entanglement, and searching a semantic network contribute to event memory

Free association norms indicate that words are organized into semantic/associative neighborhoods within a larger network of words and links that bind the net together. We present evidence indicating that memory for a recent word event can depend on implicitly and simultaneously activating related words in its neighborhood. Processing a word during encoding primes its network representation as a function of the density of the links in its neighborhood. Such priming increases recall and recognition and can have long lasting effects when the word is processed in working memory. Evidence for this phenomenon is reviewed in extralist cuing, primed free association, intralist cuing, and single-item recognition tasks. The findings also show that when a related word is presented to cue the recall of a studied word, the cue activates it in an array of related words that distract and reduce the probability of its selection. The activation of the semantic network produces priming benefits during encoding and search costs during retrieval. In extralist cuing recall is a negative function of cue-to-distracter strength and a positive function of neighborhood density, cue-to-target strength, and target-to cue strength. We show how four measures derived from the network can be combined and used to predict memory performance. These measures play different roles in different tasks indicating that the contribution of the semantic network varies with the context provided by the task. We evaluate spreading activation and quantum-like entanglement explanations for the priming effect produced by neighborhood density.

Civil procedure : Commentary and materials

This book provides a comprehensive analysis of the practical and theoretical issues encountered in Australian civil procedure. Each chapter features in-depth questions and notes together with lists of further reading to aid understanding of the issue. It also examines and discusses each substantive and procedural step in the trial process. Topics include jurisdiction of a court to consider a matter, limitations of actions, commencing proceedings, service, interlocutory proceedings, pleading, gathering evidence, trial and appeal, costs and practice directions. Each of the state, territory and federal procedures is covered.

Civil Procedure : Commentary and Materials (2nd ed)

This book provides a comprehensive analysis of the practical and theoretical issues encountered in Australian civil procedure, including alternative dispute resolution. Each chapter features in-depth questions and notes together with lists of further reading to aid understanding of the issue. It also examines and discusses each substantive and procedural step in the trial process. Topics include jurisdiction of a court to consider a matter, court adjudication under an adversarial system, alternative dispute resolution. limitations of actions, commencing proceedings, pleading, gathering evidence, trial and appeal, costs and enforcement. Each of the state, territory and federal procedures is covered.

SAIVT-QUT@TRECVid 2012 : interactive surveillance event detection

In this paper, we propose an approach which attempts to solve the problem of surveillance event detection, assuming that we know the definition of the events. To facilitate the discussion, we first define two concepts. The event of interest refers to the event that the user requests the system to detect; and the background activities are any other events in the video corpus. This is an unsolved problem due to many factors as listed below: 1) Occlusions and clustering: The surveillance scenes which are of significant interest at locations such as airports, railway stations, shopping centers are often crowded, where occlusions and clustering of people are frequently encountered. This significantly affects the feature extraction step, and for instance, trajectories generated by object tracking algorithms are usually not robust under such a situation. 2) The requirement for real time detection: The system should process the video fast enough in both of the feature extraction and the detection step to facilitate real time operation. 3) Massive size of the training data set: Suppose there is an event that lasts for 1 minute in a video with a frame rate of 25fps, the number of frames for this events is 60X25 = 1500. If we want to have a training data set with many positive instances of the event, the video is likely to be very large in size (i.e. hundreds of thousands of frames or more). How to handle such a large data set is a problem frequently encountered in this application. 4) Difficulty in separating the event of interest from background activities: The events of interest often co-exist with a set of background activities. Temporal groundtruth typically very ambiguous, as it does not distinguish the event of interest from a wide range of co-existing background activities. However, it is not practical to annotate the locations of the events in large amounts of video data. This problem becomes more serious in the detection of multi-agent interactions, since the location of these events can often not be constrained to within a bounding box. 5) Challenges in determining the temporal boundaries of the events: An event can occur at any arbitrary time with an arbitrary duration. The temporal segmentation of events is difficult and ambiguous, and also affected by other factors such as occlusions.

Efficient solution of multiple cracks in great number using eigen COD boundary integral equations with iteration procedure

A newly developed computational approach is proposed in the paper for the analysis of multiple crack problems based on the eigen crack opening displacement (COD) boundary integral equations. The eigen COD particularly refers to a crack in an infinite domain under fictitious traction acting on the crack surface. With the concept of eigen COD, the multiple cracks in great number can be solved by using the conventional displacement discontinuity boundary integral equations in an iterative fashion with a small size of system matrix to determine all the unknown CODs step by step. To deal with the interactions among cracks for multiple crack problems, all cracks in the problem are divided into two groups, namely the adjacent group and the far-field group, according to the distance to the current crack in consideration. The adjacent group contains cracks with relatively small distances but strong effects to the current crack, while the others, the cracks of far-field group are composed of those with relatively large distances. Correspondingly, the eigen COD of the current crack is computed in two parts. The first part is computed by using the fictitious tractions of adjacent cracks via the local Eshelby matrix derived from the traction boundary integral equations in discretized form, while the second part is computed by using those of far-field cracks so that the high computational efficiency can be achieved in the proposed approach. The numerical results of the proposed approach are compared not only with those using the dual boundary integral equations (D-BIE) and the BIE with numerical Green's functions (NGF) but also with those of the analytical solutions in literature. The effectiveness and the efficiency of the proposed approach is verified. Numerical examples are provided for the stress intensity factors of cracks, up to several thousands in number, in both the finite and infinite plates.

Civil procedure : commentary and materials (3rd ed.)

This book provides a comprehensive analysis of the practical and theoretical issues encountered in Australian civil procedure, including alternative dispute resolution. Each chapter features in-depth questions and notes together with lists of further reading to aid understanding of the issue. It also examines and discusses each substantive and procedural step in the trial process. Topics include jurisdiction of a court to consider a matter, alternative dispute resolution. limitations of actions, commencing proceedings, pleading, gathering evidence, trial and appeal, costs and practice directions. The procedures in the Supreme Courts of each of the states and Territories are covered, as well as those of the Federal Court of Australia.

Civil procedure : commentary and materials (4th ed)

This book provides a comprehensive analysis of the practical and theoretical issues encountered in Australian civil procedure, including alternative dispute resolution. Each chapter features in-depth questions and notes together with lists of further reading to aid understanding of the issue. It also examines and discusses each substantive and procedural step in the trial process. Topics include jurisdiction of a court to consider a matter, alternative dispute resolution, limitations of actions, commencing proceedings, pleading, gathering evidence, trial and appeal, costs and practice directions. Each of the state, territory and federal procedures is covered.

Practice and Procedure : UCPR r 95

In Energex Limited v Sablatura [2009] QSC 356 the difficulty facing the applicant related not to its substantive rights, but to its ability to vindicate those rights without an effective respondent to the application. The case highlights issues that may confront an applicant or plaintiff in vindicating rights it may have against a person who is or becomes under a legal incapacity, if there is no-one other than the Public Trustee able to act as litigation guardian.