MediaPlayer™ versus RealPlayer™ - A Comparison of Network Turbulence

The development of higher speed Internet connections and improvements in streaming media technology promise to increase the volume of streamed media over the Internet. The performance of currently available streaming media products will play an important role in the network impact of streaming media. However, there are few empirical studies that analyze the network traffic characteristics and Internet impact of current streaming media products. This paper presents analysis from an empirical study of the two dominant streaming multimedia products, RealNetworks RealPlayer™ and Microsoft MediaPlayer™. Utilizing two custom media player measurement tools, RealTracker and MediaTracker, we are able to gather application layer and network layer information about RealPlayer and MediaPlayer for the same media under the same network conditions. Our analysis shows that RealPlayer and MediaPlayer have distinctly different behavior characteristics. The packet sizes and rates generated by MediaPlayer are essentially CBR while the packet sizes and rates generated by RealPlayer are more varied. During initial delay buffering, MediaPlayer sends data at the same rate as during playout while RealPlayer can buffer at up to three times the playout rate. For high bandwidth clips, MediaPlayer sends frames that are larger than the network MTU, resulting in multiple IP fragments for each application level frame. From the application perspective, for low bandwidth clips, MediaPlayer has a lower frame rate than RealPlayer. Our work exposes some of the impact of streaming media on the network and provides valuable information for building more realistic streaming media simulations

Research Resources for Network Application Studies

The growth of computer networks has led to increasing diversity of Internet applications, including streaming media and network games. However, without precise information on how network and system improvements benefit the networked application user, it is difficult to properly assess the benefits of new network treatments or to design the next generation networks that will effectively support the QoS of emerging applications. This research attempts to bridge this gap in understanding with three innovative projects: 1) integrating measures of network performance with user perception; 2) quality of service for network games; and 3) perceived quality of adaptive streaming media repair. With the requested research resources, we have developed an application performance studies laboratory that allows us to finely control network performance for a range of selected networked applications. Each project shares research resources in the new laboratory to measure performance for interactive applications, network games and streaming media repair, as appropriate

Teaching Technology Fellowship Report on “Demonstration/Measurement System for Wireless Networks”

This paper is the final report for a Teaching Technology Fellowship project conducted between July 2005 and May 2007. This project involved integrating a wireless network measurement experiment into the curriculum of CS4514, Computer Networks, during the WPI B06 undergraduate term. After presenting goals and objectives, the chronology of preparation and execution of the project plan are discussed. The paper assesses the results of the B06 wireless measurement experience against a B05 offering of Computer Networks that included a wireless design assignment. A discussion of observations about the positive and negative aspects of this experimental pedagogical effort is provided as a summary

On combining temporal scaling and quality scaling for streaming MPEG

Temporal Scaling and Quality Scaling are both widely-used techniques to reduce the bitrate of streaming video. How-ever, combinations and comparisons of Temporal and Qual-ity Scaling have not been systematically studied. This re-search extends previous work to provide a model for combin-ing Temporal and Quality Scaling, and uses an optimization algorithm to provide a systematic analysis of their combina-tion over a range of network conditions and video content. Analytic experiments show: 1) Quality Scaling typically per-forms better than Temporal Scaling, with performance dif-ferences correlated with the motion characteristics of the video. In fact, when the network capacity is moderate and the loss rate is low, Quality Scaling performs nearly as well as the optimal combination of Quality and Temporal Scal-ing; 2) when the network capacity is low and the packet loss rate is high, Quality Scaling alone is ineffective, but a combination of Quality and Temporal Scaling can provide reasonable video quality; 3) adjusting the amount of For-ward Error Correction (FEC) provides significantly better performance than video streaming without FEC or video streaming with a fixed amount of FEC. 1

Exile Vol. XLIX

47th Year Title Page 3 Epigraph by Ezra Pound 5 Table of Contents 7 Contributors\u27 Notes 62-63 Editorial Board 64 ART Hidden by Elizabeth Averbeck \u2704 8 Untitled by Laura Cannon \u2705 10 Untitled by Matt Messmer \u2706 16 Hierve el agua by Emily stenken \u2703 18 A Late One by Sarah R. Smith \u2703 27 Between the Lines by Gregory Holden \u2703 30 Carwash by Gregory Holden \u2703 40 Untitled by Laura Cannon \u2705 42 Flowers in Her Hair by Gregory Holden \u2703 53 Untitled Forrest by Jessica Kramer \u2703 56 POETRY What the Dead Had Grown by Steve Kovach \u2703 9 European Affairs by Ginna Fuselier \u2703 17 Combing the Everglades by Scott Barsotti \u2703 28-29 Persecution by Steve Kovach \u2703 41 A few coins in a styrofoam cup by Miranda Bodfish \u2705 54-55 FICTION Here\u27s to Mary by Katie Mannel \u2705 11-15 The Game of Right by Bradley Prefling \u2703 19-26 The Interview by Nicole Bennett \u2704 31-39 Jet Black Chevrolet by Scott Barsotti \u2703 43-52 Fulfilling Duty by Daniel Kinicki \u2705 57-61 All submissions are reviewed on an anonymous basis, and all editorial decisions are shared equally among the members of the Editorial Board. -64 Cover Art Despair by Gregory Holden \u2703 / Back Cover Art Untitled by Laura Cannon \u2705 -64 Printing by Printing Arts Press -64 Scott Barsotti, Jet Black Chevrolet redacted due to copyright restrictions

Feedback type as a moderator of the relationship between achievement goals and feedback reactions

The aim of the current study is to shed new light on the inconsistent relationship between performance-approach (PAp) goals and feedback reactions by examining feedback type as a moderator. Results of a field experiment (N = 939) using a web-based work simulation task showed that the effect of achievement-approach goals was moderated by feedback type. Relative to individuals pursuing mastery-approach goals, individuals pursuing PAp goals responded more negatively to comparative feedback but not to task-referenced feedback. In line with the hypothesized mediated moderation model, the interaction between achievement goals and feedback type also indirectly affected task performance through feedback reactions. Providing employees with feedback is a key psychological principle used in a wide range of human resource and performance management instruments (e.g., developmental assessment centres, multi-source/360 degrees feedback, training, selection, performance appraisal, management education, computer-adaptive testing, and coaching). The current study suggests that organizations need to strike a balance between encouraging learning and encouraging performance, as too much emphasis on comparative performance (both in goal inducement and in feedback style) may be detrimental to employees' reactions and rate of performance improvement