Exploiting iteration-level parallelism in dataflow programs

The term "dataflow" generally encompasses three distinct aspects of computation - a data-driven model of computation, a functional/declarative programming language, and a special-purpose multiprocessor architecture. In this paper we decouple the language and architecture issues by demonstrating that declarative programming is a suitable vehicle for the programming of conventional distributed-memory multiprocessors.This is achieved by appling several transformations to the compiled declarative program to achieve iteration-level (rather than instruction-level) parallelism. The transformations first group individual instructions into sequential light-weight processes, and then insert primitives to: (1) cause array allocation to be distributed over multiple processors, (2) cause computation to follow the data distribution by inserting an index filtering mechanism into a given loop and spawning a copy of it on all PEs; the filter causes each instance of that loop to operate on a different subrange of the index variable.The underlying model of computation is a dataflow/von Neumann hybrid in that exection within a process is control-driven while the creation, blocking, and activation of processes is data-driven.The performance of this process-oriented dataflow system (PODS) is demonstrated using the hydrodynamics simulation benchmark called SIMPLE, where a 19-fold speedup on a 32-processor architecture has been achieved

Executing matrix multiply on a process oriented data flow machine

The Process-Oriented Dataflow System (PODS) is an execution model that combines the von Neumann and dataflow models of computation to gain the benefits of each. Central to PODS is the concept of array distribution and its effects on partitioning and mapping of processes.In PODS arrays are partitioned by simply assigning consecutive elements to each processing element (PE) equally. Since PODS uses single assignment, there will be only one producer of each element. This producing PE owns that element and will perform the necessary computations to assign it. Using this approach the filling loop is distributed across the PEs. This simple partitioning and mapping scheme provides excellent results for executing scientific code on MIMD machines. In this way PODS allows MIMD machines to exploit vector and data parallelism easily while still providing the flexibility of MIMD over SIMD for multi-user systems.In this paper, the classic matrix multiply algorithm, with 1024 data points, is executed on a PODS simulator and the results are presented and discussed. Matrix multiply is a good example because it has several interesting properties: there are multiple code-blocks; a new array must be dynamically allocated and distributed; there is a loop-carried dependency in the innermost loop; the two input arrays have different access patterns; and the sizes of the input arrays are not known at compile time. Matrix multiply also forms the basis for many important scientific algorithms such as: LU decomposition, convolution, and the Fast-Fourier Transform.The results show that PODS is comparable to both Iannucci's Hybrid Architecture and MIT's TTDA in terms of overhead and instruction power. They also show that PODS easily distributes the work load evenly across the PEs. The key result is that PODS can scale matrix multiply in a near linear fashion until there is little or no work to be performed for each PE. Then overhead and message passing become a major component of the execution time. With larger problems (e.g., >/=16k data points) this limit would be reached at around 256 PEs

Providing Consistent Service at the Concessions Stand: a Potential Problem

Concession sales are a critical revenue stream for sport and entertainment venues. Most research investigating concession revenues has focused upon quality and availability of food choices as well as the servicescape (Bigelow, 2004; Zeithaml, Bitner, & Gremler, 2006). Though these are important areas of concern, one area that has not been extensively researched is the appearance, speed, and efficiency of individual concession stations in relation to their in-venue counterparts. This study investigated the consistency of concession operations at a National Collegiate Athletic Association (NCAA) Division I men’s basketball game. Results indicated that a large discrepancy existed among concession outlets in regards to physical appearance of the environment, number of staff members working, and speed of customer transactions

Automatic data/program partitioning using the single assignment principle

Loosely-coupled MIMD architectures do not suffer from memory contention; hence large numbers of processors may be utilized. The main problem, however, is how to partition data and programs in order to exploit the available parallelism. In this paper we show that efficient schemes for automatic data/program partitioning and synchronization may be employed if single assignment is used. Using simulations of program loops common to scientific computations (the Livermore Loops), we demonstrate that only a small fraction of data accesses are remote and thus the degradation in network performance due to multiprocessing is minimal

Free Ride, Take it Easy: An Empirical Analysis of Adverse Incentives Caused by Revenue Sharing

A fundamental belief in professional sport leagues is that competitive balance is needed to maximize demand and revenues; therefore, leagues have created policies attempting to attain proper competitive balance. Further, research posits that objectives of professional sport teams’ owners include some combination of winning and profit maximization. Although the pursuit of wins is a zero sum game, revenue generation and potential profit making is not. This article focuses upon the National Football League’s potential unintended consequences of creating the incentive for some teams to free ride on the rest of the league’s talent and brand. It examines whether an owner’s objectives to generate increased revenues and profits are potentially enhanced by operating as a continual low-cost provider while making money from the shared revenues and brand value of the league. The present evidence indicates that, overall, being a low-cost provider is more profitable than increasing player salaries in an attempt to win additional games.free riding; free ride; football; profit maximization; regression; owner incentives

Major League Baseball Anti-Trust Immunity: Examining the Legal and Financial Implications of Relocation Rules

Major League Baseball (MLB) rules restrict the movement of any franchise into another’s territory. These territorial rules are designed to protect each team’s potential local revenue sources as well as to provide stability throughout the league. Recently, Major League Baseball approved financial compensation for the Washington Nationals move into the Baltimore Orioles’ territory – primarily because it was in the best interest of MLB even though it hurt the Orioles. However, the Oakland Athletics were unable to even negotiate a potential compensation plan for a move into the San Francisco Giants territory, despite the apparent financial benefit the move could have provided for every other league franchise. The Athletics are already located within 15 miles of the Giants, and their potential 40 mile move to San Jose, California would not add a new team to the San Francisco Bay Area; rather, it would simply be a move of a current team to a different location within the metropolitan area. The refusal of the Giants or MLB to negotiate a potential compromise has kept the Oakland Athletics in a substandard facility and has led to their potential move to Fremont, CA – a less desirable location than San Jose. This paper investigates the legal, policy, and financial considerations concerning Major League Baseball’s territorial rules. Specifically, it addresses antitrust law as it pertains to American professional sport, relative sport franchise relocation cases, financial arguments why leagues desire to control relocation, financial components of MLB’s current Collective Bargaining Agreement, and the legal and financial impact of a challenge to MLB’s territorial rules – an option the Oakland Athletic initially investigated prior to their decision to pursue a potential move to Fremont.Antitrust law; Collective Bargaining Agreement; Franchise Relocation; Major League Baseball; Revenue Sharing; Territorial Rights

Providing Consistent Service at the Concession Stands: An Exploratory Study

Concession sales are a critical revenue stream for sport and entertainment venues. Most research investigating concession revenues has focused upon quality and availability of food choices as well as the servicescape (Bigelow, 2004; Zeithaml, Bitner, and Gremler, 2006). Though these are important areas of concern, one area that has not been extensively researched is the appearance, speed, and efficiency of individual concession stations in relation to their in-venue counterparts. This study investigated the consistency of concession operations at a National Collegiate Athletic Association (NCAA) Division I men’s basketball game. Results indicated that a discrepancy existed among concession outlets in regards to physical appearance and speed of customer transactions

Treatment of Travel Expenses by Golf Course Patrons: Sunk or Bundled Costs and the First and Third Laws of Demand

To attract golf patrons, sport managers must understand consumption patterns of the golfer. Importantly, the treatment of travel costs must be understood. According to the Alchian-Allen (1964) theorem, golfers treat travel costs as bundled costs (third law of economic demand) whereas classical consumer theory indicates that golfers treat travel costs as sunk costs (first law of economic demand). The purpose of this study was to determine if golf patrons treated travel costs as sunk costs or if they treated travel costs as a bundled cost. Data from a survey of course patrons in Ohio support the treatment of travel costs as bundled costs by golf course patrons, especially those classified as tourists. Managers should utilize geographic segmentation in choosing whom to market their course based upon their product’s price compared to area competitors, as shown by the strong, positive correlation found between distance traveled and cost of green fees.Alchian-Allen Theorem; Third Law of Demand; Golf Tourism; Bundling

Major League Baseball and Globalization: The World Baseball Classic

In addition to generating initial profits, the WBC has positioned MLB to be the leader in growing the game of baseball and the commercial aspects of the sport throughout the world. As baseball grows, and more importantly as the American brand of baseball grows, it will be interesting to watch the worldwide reaction – particularly if MLB begins to generate huge profits overseas. Other prominent American brands such as Coke, Nike, Disney, and McDonalds have been both embraced and scorned as they have ventured beyond the fifty U.S. states. MLB will have unique challenges, but also tremendous opportunities as they attempt to expand their potential marketplace from 330 million consumers to the entire world. Ultimately, the long-term impact of the initial World Baseball Classic will not be known for many years, but it appears that the initial tournament met, and in some cases, exceeded expectations.World Baseball Classic; WBC; globalization