Scalable Overlay Multicast Tree Construction for QoS-Constrained Media Streaming

Overlay networks have become popular in recent times for content distribution and end-system multicasting of media streams. In the latter case, the motivation is based on the lack of widespread deployment of IP multicast and the ability to perform end-host processing. However, constructing routes between various end-hosts, so that data can be streamed from content publishers to many thousands of subscribers, each having their own QoS constraints, is still a challenging problem. First, any routes between end-hosts using trees built on top of overlay networks can increase stress on the underlying physical network, due to multiple instances of the same data traversing a given physical link. Second, because overlay routes between end-hosts may traverse physical network links more than once, they increase the end-to-end latency compared to IP-level routing. Third, algorithms for constructing efficient, large-scale trees that reduce link stress and latency are typically more complex. This paper therefore compares various methods to construct multicast trees between end-systems, that vary in terms of implementation costs and their ability to support per-subscriber QoS constraints. We describe several algorithms that make trade-offs between algorithmic complexity, physical link stress and latency. While no algorithm is best in all three cases we show how it is possible to efficiently build trees for several thousand subscribers with latencies within a factor of two of the optimal, and link stresses comparable to, or better than, existing technologies

Extending snBench to Support Hierarchical and Configurable Scheduling

It is useful in systems that must support multiple applications with various temporal requirements to allow application-specific policies to manage resources accordingly. However, there is a tension between this goal and the desire to control and police possibly malicious programs. The Java-based Sensor Execution Environment (SXE) in snBench presents a situation where such considerations add value to the system. Multiple applications can be run by multiple users with varied temporal requirements, some Real-Time and others best effort. This paper outlines and documents an implementation of a hierarchical and configurable scheduling system with which different applications can be executed using application-specific scheduling policies. Concurrently the system administrator can define fairness policies between applications that are imposed upon the system. Additionally, to ensure forward progress of system execution in the face of malicious or malformed user programs, an infrastructure for execution using multiple threads is described

AN AMERICAN-BASED STUDY EXAMINING THE RELATIONSHIP BETWEEN PARTICIPANTS’ DEMOGRAPHIC PROFILES AND ATTITUDES REGARDING BUSINESS OUTSOURCING TECHNIQUES AND STRATEGIES

The world is a global marketplace, however much inquiry has been created regarding American-based companies relocating departmental operations offshore to foreign territories. Keating (2012) indicated that popular areas for companies to reposition operations include customer service, information technology, and sales services. The main reason for moving offshore is to cut costs and to maximize on cheaper labor pools in the host country. There are cultural and language barriers that complicate matters, as well as, the media, as reported by Dobbs (2004) in the United States (U.S.) brings supposition by broadcasting the jobs lost by U.S. employees, as well as, home country power diminishing by stronger global players rising and thriving, such as, Brazil, The Philippines, and Mexico. This study quantifiably examined the relationship between participants’ demographic profiles and attitudes regarding business outsourcing techniques and strategies utilizing the Chi-Square and Fisher’s Exact tests, to gain a greater understanding of what these American-based beliefs truly are, in relation to, the sample confined within this study. Areas of concern examined attitudes towards managers, as well as, the U.S. government, regarding engaging in business outsourcing endeavors, enforcing policies to keep jobs in America, operating with a global mindset, helping people in both the home and host countries, competence factors associated with the capabilities to head outsourcing efforts based upon gender, and the training needed to successfully move operations offshore, for example. Significant differences were found in all of the demographic variables of ethnicity, gender, number of children (e.g. family size), age, education level, marital status, and annual household income

Defying the Conventional: Musical Performance, Embodied Cognition, and the Reconfiguration of Institutional Discourse

This essay confronts the dialectic between theory and practice through a comparison of an idea basic to how we understand music (the notion that pitch moves up and down in vertical space) with how pitch is thought of in actual music-making. The comparison leads to both a new conceptual model for thinking about pitch, what might be called Pitch Horizontality, as well as a proposal for how to bring institutional discourse about music into sync, not with how scholars in other disciplines think about their subject matter, but with the thinking that goes on in contexts of real-world artistic production