Video alignment to a common reference

2015 Spring.Includes bibliographical references.Handheld videos often include unintentional motion (jitter) and intentional motion (pan and/or zoom). Human viewers prefer to see jitter removed, creating a smoothly moving camera. For video analysis, in contrast, aligning to a fixed stable background is sometimes preferable. This paper presents an algorithm that removes both forms of motion using a novel and efficient way of tracking background points while ignoring moving foreground points. The approach is related to image mosaicing, but the result is a video rather than an enlarged still image. It is also related to multiple object tracking approaches, but simpler since moving objects need not be explicitly tracked. The algorithm presented takes as input a video and returns one or several stabilized videos. Videos are broken into parts when the algorithm detects background change and it becomes necessary to fix upon a new background. We present two techniques in this thesis. One technique stabilizes the video with respect to the first available frame. Another technique stabilizes the videos with respect to a best frame. Our approach assumes the person holding the camera is standing in one place and that objects in motion do not dominate the image. Our algorithm performs better than previously published approaches when compared on 1,401 handheld videos from the recently released Point-and-Shoot Face Recognition Challenge (PASC)

The Dynamics of Organizational Information Security

In recent times, it has become evident that information security is not achieved through technology alone. Rather, it depends on a complex interplay among technology, organizational and managerial issues, and events in the external environment. Senior management attention, training, and sound operating procedures are just as important as firewalls and virtual private networks in arriving at a robust security posture. In this paper, we represent the interactions among these technical and organizational drivers using the system dynamics methodology, to develop a high level model of organizational information security. Since the basic system dynamics construct is the feedback loop, our model is able to expose the counteracting mechanics that work to reinforce and erode security, respectively. By doing so, it can inform the process of crafting an appropriate level of security—a problem facing most organizations. Since the model is based on simulation, it is also possible to test what-if scenarios of how the security posture of the organization would fare under different levels of external threats and management policies

Optimal Scheduling Policies for Remote Estimation of Autoregressive Markov Processes over Time-Correlated Fading Channel

We consider the problem of transmission scheduling for the remote estimation of a discrete-time autoregressive Markov process that is driven by white Gaussian noise. A sensor observes this process, and then decides to either encode the current state of this process into a data packet and attempts to transmit it to the estimator over an unreliable wireless channel modeled as a Gilbert-Elliott channel, or does not send any update. Each transmission attempt consumes $\lambda$ units of transmission power, and the remote estimator is assumed to be linear. The channel state is revealed only via the feedback (ACK\slash NACK) of a transmission, and hence the channel state is not revealed if no transmission occurs. The goal of the scheduler is to minimize the expected value of an infinite-horizon cumulative discounted cost, in which the instantaneous cost is composed of the following two quantities: (i)~squared estimation error, (ii) transmission power. We show that this problem can equivalently be posed as a partially observable Markov decision process (POMDP), in which the scheduler maintains a belief about the current state of the channel, and makes decisions on the basis of the current value of the estimation error, and the belief state.~We then show that the optimal policy is of threshold-type, i.e. for each value of the estimation error $e$, there is a threshold b\ust(e) such that when the error is equal to $e$, then it is optimal to transmit only when the current belief state is greater than b\ust(e)

The Mechanics of Internet Diffusion in India: Lessons for Developing Countries

The issue of Internet diffusion in an economy over time is of interest to several stakeholders, including policy makers, regulators, investors, and businesses. It is particularly important in developing countries, which see the Internet as a major driver in achieving social and developmental goals. Concerns about the so-called ìdigital divideî also lend some urgency to the issue. However, Internet diffusion is driven by social as well as technical factors, and developing countries have distinctive characteristics that make their adoption process different from that in industrialized countries. This paper develops a causal model of Internet diffusion in developing countries, using the systems dynamics methodology. The modeling approach allows us to combine standard contagion mechanisms inherent in diffusion, such as innovators and imitators, with the distinctive regulatory, economic, and social circumstances in developing countries. The structure of the model is first justified using India as a specific developing country context. Next, the simulated values generated by this structural model are compared against actual values for Internet adoption in India for the period 1996ñ2001, and the fit is found to be reasonably good. These initial findings support model validity. Using a technique called dominant loop analysis the model suggests that, among all the different drivers, poor telecom- munications infrastructure and high telephone charges are the major barriers to diffusion. In conclusion, we discuss the issues to be addressed in the remainder of this ongoing work

System Dynamics Modeling Of Ict Diffusion

IS scholars have been studying the diffusion of Information and Communication Technologies (ICT) for some time now and certain research methods have emerged as the dominant ones in this body of literature. In this paper, we first note these methods citing representative studies and then present an alternate approach to studying ICT diffusion using systems dynamics (SD). Any diffusion, by nature, is a temporal phenomenon. The essence of SD is to uncover the underlying network of cause-effect relationships that is generating a temporally evolving behaviour. Thus it is a natural for studying ICT diffusion, particularly when diffusion is driven by complex interactions among contextual variables. SD has not received much attention in the ICT diffusion literature, but this method has strengths that complement those of the other methods currently in common use, thereby enhancing our understanding of the phenomenon. The characteristics of SD also make it particularly appropriate for studying ICT diffusion in the Pacific Asia region which is characterized by substantial differences in contextual variables that drive ICT diffusion, such as literacy rates, economic development and infrastructure sophistication, besides having wide diversity in cultural norms