141 research outputs found
Optimizing I/O for Big Array Analytics
Big array analytics is becoming indispensable in answering important
scientific and business questions. Most analysis tasks consist of multiple
steps, each making one or multiple passes over the arrays to be analyzed and
generating intermediate results. In the big data setting, I/O optimization is a
key to efficient analytics. In this paper, we develop a framework and
techniques for capturing a broad range of analysis tasks expressible in
nested-loop forms, representing them in a declarative way, and optimizing their
I/O by identifying sharing opportunities. Experiment results show that our
optimizer is capable of finding execution plans that exploit nontrivial I/O
sharing opportunities with significant savings.Comment: VLDB201
A study of systems implementation languages for the POCCNET system
The results are presented of a study of systems implementation languages for the Payload Operations Control Center Network (POCCNET). Criteria are developed for evaluating the languages, and fifteen existing languages are evaluated on the basis of these criteria
Investigating SRAM PUFs in large CPUs and GPUs
Physically unclonable functions (PUFs) provide data that can be used for
cryptographic purposes: on the one hand randomness for the initialization of
random-number generators; on the other hand individual fingerprints for unique
identification of specific hardware components. However, today's off-the-shelf
personal computers advertise randomness and individual fingerprints only in the
form of additional or dedicated hardware.
This paper introduces a new set of tools to investigate whether intrinsic
PUFs can be found in PC components that are not advertised as containing PUFs.
In particular, this paper investigates AMD64 CPU registers as potential PUF
sources in the operating-system kernel, the bootloader, and the system BIOS;
investigates the CPU cache in the early boot stages; and investigates shared
memory on Nvidia GPUs. This investigation found non-random non-fingerprinting
behavior in several components but revealed usable PUFs in Nvidia GPUs.Comment: 25 pages, 6 figures. Code in appendi
Quadsim Version 2.1 Student Manual
Quadsim is an intermediate code simulator. It allows you to "run" programs that your compiler generates in intermediate code format. Its user interface is similar to most debuggers in that you can step through your program, instruction by instruction, set breakpoints, examine variable values, and so on.
The intermediate code format used by Quadsim is that described in [Aho 86]. If your compiler generates intermediate code in this format, you will be able to take intermediate-code files generated by your compiler, load them into the simulator, and watch them "run." You are provided with functions that hide the internal representation of intermediate code. You can use these functions within your compiler to generate intermediate code files that can be read by the simulator.
Quadsim was inspired and greatly influenced by [Aho 86]. The material in chapter 8 (Intermediate Code Generation) of [Aho 86] should be considered background material for users of Quadsim
Multiple-View Tracing for Haskell: a New Hat
Different tracing systems for Haskell give different views of a program at work. In practice, several views are complementary and can productively be used together. Until now each system has generated its own trace, containing only the information needed for its particular view. Here we present the design of a trace that can serve several views. The trace is generated and written to file as the computation proceeds. We have implemented both the generation of the trace and several different viewers
A Specification Environment That Supports the Prototyping of Distributed Systems Using an Object-Oriented Model.
High-speed computer networking, interactive service, and incremental growth for computing are some of the motivations for developing a distributed system. Despite the inherent benefits of a distributed system, the development of software support is more difficult for distributed systems than for sequential systems. In either case, difficulties may arise from the communication problems between two groups of people with different backgrounds trying to formulate requirements for the system. This process depends on feedback and may take many iterations to converge. Customers can usually recognize the features they need when they start using a system, which makes prototyping an important tool in requirement analysis. Many prototyping goals, objectives, and approaches are possible. Executable formal specifications are the most attractive ones. This unification of specification and prototyping by having code generators has advantages of providing consistency and prototyping at higher levels of abstraction. Thus, a methodology for executing the DOSL (Distributed Object-based Specification Language) is defined and a prototype system is developed. DOSL is extended as a new formal distributed object-oriented specification language, DOSL-II. DOSL-II is object-oriented rather than object-based, and includes class, inheritance, simple I/O, stream I/O, concurrent I/O, and new constructs for object communication
Feasibility study of an Integrated Program for Aerospace vehicle Design (IPAD). Volume 6: IPAD system development and operation
The strategy of the IPAD implementation plan presented, proposes a three phase development of the IPAD system and technical modules, and the transfer of this capability from the development environment to the aerospace vehicle design environment. The system and technical module capabilities for each phase of development are described. The system and technical module programming languages are recommended as well as the initial host computer system hardware and operating system. The cost of developing the IPAD technology is estimated. A schedule displaying the flowtime required for each development task is given. A PERT chart gives the developmental relationships of each of the tasks and an estimate of the operational cost of the IPAD system is offered
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