A Hierarchy of Scheduler Classes for Stochastic Automata

Stochastic automata are a formal compositional model for concurrent stochastic timed systems, with general distributions and non-deterministic choices. Measures of interest are defined over schedulers that resolve the nondeterminism. In this paper we investigate the power of various theoretically and practically motivated classes of schedulers, considering the classic complete-information view and a restriction to non-prophetic schedulers. We prove a hierarchy of scheduler classes w.r.t. unbounded probabilistic reachability. We find that, unlike Markovian formalisms, stochastic automata distinguish most classes even in this basic setting. Verification and strategy synthesis methods thus face a tradeoff between powerful and efficient classes. Using lightweight scheduler sampling, we explore this tradeoff and demonstrate the concept of a useful approximative verification technique for stochastic automata

Linear TV In The Non-Linear World: The Value of Linear Scheduling Amidst the Proliferation of Non-Linear Platforms

Unprecedented technological innovations in media content consumption have had a profound impact on the network television industry. Television networks' control has waned since the advent of alternative platforms for content viewing. Audiences have been released from the clutches of the linear schedule. They now have the freedom to customize viewing based on their content and platform preferences, and availability. The purpose of this qualitative study is to assess 1) the current value of television linear scheduling and 2) the effectiveness of traditional strategies in this present phase of channel and platform proliferation. An additional goal is to identify new strategies that are employed by broadcasters to accommodate the audience's changing viewing habits. Thus, the author primarily interviewed experienced television executives who were currently in-charge of scheduling television shows. Their insights have led to the conclusion that scheduling remains relevant in this age of non-linear viewing. However, its functions adapt and its scope expands beyond linear. There are also key changes in the approaches and thought-processes in scheduling. Furthermore, new systems have been identified, which are currently utilized in attracting audiences to consume content via live television. As television insiders have differing opinions, it is suggested that the effectiveness of these new systems be researched further. Keywords: television scheduling, television programming, linear scheduling, lead-in, non-linear viewingM.S., Television Management -- Drexel University, 201

Logical partitioning of parallel system simulations

Simulation has been a fundamental tool to prototype, hypothesize, and evaluate new ideas to continue improving system performance. However, increasing levels of processor parallelism and heterogeneity have introduced additional constraints when evaluating new designs. The work embodied in this dissertation explores how to leverage novel ideas in simulator partitioning to improve simulator speed and flexibility for simulating these new types of systems. The contribution of this work includes the introduction of optimistic partitioned simulation to improve parallelization, and the introduction of warped partitioned simulation for improved flexibility. These ideas are refined and demonstrated through the use of prototypes to demonstrate their benefits compared to state-of-the-art approaches. By leveraging partitioning in a structured manner, it is possible to design simulators that better address the open challenges of parallel and heterogeneous systems design.Electrical and Computer Engineerin

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Student newspaper for the UNF community

La Salle University Graduate Bulletin 1999-2000

Issued for La Salle University Graduate Programs 1999-2000https://digitalcommons.lasalle.edu/course_catalogs/1167/thumbnail.jp

Digital Scripture: An Investigation of the Design and Use of a Mobile Application for Reading Sacred Text

Digital sacred text reading is rapidly growing as digital devices such as mobile smartphones are becoming more common across the globe. Although sacred text can have strong influence on identify and behavior, the effects of a digital revolution on scripture reading practices are not well understood. In particular, current research literature indicates that more information is needed about the design and use of digital sacred text applications (apps) such as mobile Bibles across different religious groups or cultures. Therefore, this study builds upon and extends previous work to analyze a religious text app, Gospel Library, which is designed and largely used by members of The Church of Jesus Christ of Latter-day Saints. Data about the design of the app were collected by analyzing app store description text, conducting a technical app walkthrough, and interviewing current app design team members. Data about the usage of Gospel Library were collected by gaining permission from the design organization to access user analytic data collected during normal app operations. Results of the study show that this digital sacred text app is designed and used in ways that support religious or cultural reading values and norms. In particular, this study suggests that Latter-day Saints appear to value the King James Version of the English Bible and other unique religious text such as the Book of Mormon and General Conference sermons or messages. Results also suggest Latter-day Saints value church-wide directed scripture reading efforts situated in a culture of listening and receiving interpretation as opposed to social discussions of scripture. Furthermore, this study reports unique features or affordances that digital sacred texts can offer including audio capabilities, videos, search functions, sharing, highlighting, and other annotations. This study contributes to the research field of digital sacred text literacy by offering data gathered from an app design organization including interviews and user analytic data. It also adds to the broader conversation about religious literacy and digital versus print-based reading

La Salle University Academic Bulletin 1995-1996

Issued for La Salle University 1995-1996https://digitalcommons.lasalle.edu/course_catalogs/1158/thumbnail.jp

On the Importance of Infrastructure-Awareness in Large-Scale Distributed Storage Systems

Big data applications put significant latency and throughput demands on distributed storage systems. Meeting these demands requires storage systems to use a significant amount of infrastructure resources, such as network capacity and storage devices. Resource demands largely depend on the workloads and can vary significantly over time. Moreover, demand hotspots can move rapidly between different infrastructure locations. Existing storage systems are largely infrastructure-oblivious as they are designed to support a broad range of hardware and deployment scenarios. Most only use basic configuration information about the infrastructure to make important placement and routing decisions. In the case of cloud-based storage systems, cloud services have their own infrastructure-specific limitations, such as minimum request sizes and maximum number of concurrent requests. By ignoring infrastructure-specific details, these storage systems are unable to react to resource demand changes and may have additional inefficiencies from performing redundant network operations. As a result, provisioning enough resources for these systems to address all possible workloads and scenarios would be cost prohibitive. This thesis studies the performance problems in commonly used distributed storage systems and introduces novel infrastructure-aware design methods to improve their performance. First, it addresses the problem of slow reads due to network congestion that is induced by disjoint replica and path selection. Selecting a read replica separately from the network path can perform poorly if all paths to the pre-selected endpoints are congested. Second, this thesis looks at scalability limitations of consensus protocols that are commonly used in geo-distributed key value stores and distributed ledgers. Due to their network-oblivious designs, existing protocols redundantly communicate over highly oversubscribed WAN links, which poorly utilize network resources and limits consistent replication at large scale. Finally, this thesis addresses the need for a cloud-specific realtime storage system for capital market use cases. Public cloud infrastructures provide feature-rich and cost-effective storage services. However, existing realtime timeseries databases are not built to take advantage of cloud storage services. Therefore, they do not effectively utilize cloud services to provide high performance while minimizing deployment cost. This thesis presents three systems that address these problems by using infrastructure-aware design methods. Our performance evaluation of these systems shows that infrastructure-aware design is highly effective in improving the performance of large scale distributed storage systems