Amy Csizmar Dalal

Carleton College · Computer Science

Self-healing networks, or computer networks that can detect existing or potential pathologies and mitigate them with minimal human intervention, are particularly attractive in the home networking space, as home networks are heterogeneous and are typically configured and maintained by non-experts. Home networks greatly benefit from the ability to in...

We consider several key questions in the design of a real time video quality assessment system. How frequently can we generate subjective video quality ratings with some degree of accuracy? How often should we sample the data? How do we weigh the need to consolidate data collection (arguing for fewer, less frequent data points) with the need to mon...

While subjective measurements are the most natural for assessing the user-perceived quality of a media stream, there are issues with their scalability and their context accuracy. We explore techniques to select application-layer measurements, collected by an instrumented media player, that most accurately predict the subjective quality rating that...

Real-time stream quality assessment can assist network operators, content providers, streaming servers, and ISPs in evaluating their customers’ quality of experience (QoE), and can lead to better design of streaming protocols, computer networks, and content delivery systems. In previous work, we demonstrated that objective data collected from an in...

We present a case study of a multi-year, academic civic engagement (ACE) collaboration in a computer science capstone course. ACE projects in computer science provide an avenue for students to apply software development concepts to real-world projects with actual clients, and can offer meaningful engagement with ethical issues. The typical time-lim...

We present the results of a preliminary study into the usability of troubleshooting terminology around home computer networks. Forty-seven participants classified 29 terms, selected from interview transcripts and online help forums, in an open card sort. We analyzed words participants explicitly indicated as unfamiliar as well as words that partici...

The present teachings provide for a method and system for facilitating content download to one or more remote devices via an insecure communication channel. The method comprises the steps of receiving at least one shared secret from a device via an insecure communications channel, each shared secret encoded and functioning as an identifier for the...

We aim to develop self-healing networks that can detect degradation of streaming video quality of experience (QoE), react, and correct the pathology on the network. We present an architecture to assess real time video QoE of RTMP streams. Results from a small set of preliminary experiments demonstrate that we can predict video QoE with 70–80% accur...

In 2003, we presented an architecture for a streaming video quality assessment system [1]. Six years later, many of the challenges outlined in that paper remain. This paper revisits the 2003 architecture, pdates it given what we have learned in our experience thus far with developing the architecture, and discusses in detail the remaining challenge...

While mechanisms exist to evaluate the user-perceived quality of video streamed over computer networks, there are few good mechanisms to do so in real time. In this paper, we evaluate the feasibility of predicting the stream quality of partial portions of a video stream based on either complete or incomplete information from previously rated stream...

Computer science departments continually look for ways to make computer science more relevant to a wider population of students, to attract more students to the major and combat declining enrollments. This article describes the initial offering of a digital storytelling course within a computer science department at a small liberal arts college. Th...

Media stream quality is highly dependent on underlying network conditions, but identifying scalable, unambiguous metrics to discern the user-perceived quality of a media stream in the face of network congestion is a challenging problem. User-perceived quality can be approximated through the use of carefully chosen application layer metrics, preclud...

This paper considers the selection of features, measurements collected from an instrumented media player application, that most accurately predict the user-perceived quality of a media stream. The features are utilized by a nearest-neighbor stream quality prediction algorithm using a distance metric of dy-namic time warping. We explore three ways o...

A streaming media assessment system comprises assessment servers, media clients, data collection points, helper agents, and report servers. An assessment tool is downloaded or otherwise installed on an end-user client machine and associated with its media player. An assessment server is in communication with the assessment tool over the network and...

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We consider a M/M/1 queue in which the average reward for servicing a job is an exponentially decaying function of the job’s sojourn time. The maximum reward and mean service times of a job are i.i.d. and chosen from arbitrary distributions. The scheduler is assumed to know the maximum reward, service rate, and age of each job. We prove that the sc...

Conducting quality assessment for streaming media services, particularly from the end user perspective, has not been widely addressed by the network research community and remains a hard problem. In this paper we discuss the general problem of assessing the quality of streaming media in a large-scale IP network. This work presents two main contribu...

By putting the tools for media creation in the hands of the consumer, we anticipate exponential growth in the distribution and hosting of media on the Internet. We expect this growth to parallel that of HTTP traffic. We need to confront the issues related to this growth in the number of media sources and services. Significantly higher quality strea...

consumer, there will be exponential growth in the distribution and hosting of media on the Internet. We expect this growth to parallel that of HTTP traffic. Our position is that we need to confront the issues related to the potential exponential growth in the number of media sources and services. Further, we believe that significantly higher qualit...

By putting the tools for media creation in the hands of the consumer, there will be exponential growth in the distribu- tion and hosting of media on the Internet. We expect this growth to parallel that of HTTP traffic. Our position is that we need to confront the issues related to the potential ex- ponential growth in the number of media sources an...

We consider alternative service policies in a web server with impatient users. User-perceived performance is modeled as an exponentially decaying function of the user's waiting time, reflecting the probability that the user aborts the download before the page is completely received. The web server is modeled as a single server queue, with Poisson a...

We examine a method to improve the service of incoming requests at a World Wide Web server. The motivating factor is the existence of an impatient user pool: a user aborts a pending Web request if a response is not received within a random timeout period. We use a queueing theory approach to derive an optimal service ordering for this server, assum...