作者：
WEBBER, cLDepartment of Physiology
Loyola University of Chicago Stritch School of Medicine 2160 South First Avenue Maywood IL 60153 U.S.A.
A computer program is described which performs power-spectral analyses on time-domain data. The program is written in the clanguage and incorporates an algorithm for the fast Fourier transform translated from BASIc i...
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A computer program is described which performs power-spectral analyses on time-domain data. The program is written in the clanguage and incorporates an algorithm for the fast Fourier transform translated from BASIc into c. Sequential segments of time-domain data are accessed by the program, transformed to the frequency domain, and ensemble-averaged to generate smoothed spectra. Specific application of the program to the detection of high-frequency oscillations in the phrenic neurogram of the cat is addressed. Thus, 100 successive 512-point fast Fourier transforms were found to accurately reveal the relative strength (power) and frequency position (spectrum) of multiple peaks in this respiratory motor pathway. Because clanguage programs are very transportable, this program should run on machines other than our LSI 11/23, provided a c-compiler is available.
Next generation applications will demand more cost-effective programming abstractions to reduce increasing maintenance and development costs. In this context, the article explores the integration of an efficient progr...
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Next generation applications will demand more cost-effective programming abstractions to reduce increasing maintenance and development costs. In this context, the article explores the integration of an efficient programminglanguage and high-level real-time programming abstractions. The resulting abstraction is called Embedded cyber Physical c (EcP-c) and it is useful for designing real-time applications directly on c. The abstraction has its roots on the real-time Java: one of the most modern programminglanguages, which benefited from mature programming patterns previously developed for other languages. It also targets embedded processors running on limited hardware. EcP-c takes the programming abstractions described in real-time Java and reflects them into a c application system, providing extensions for multi-threading, resource sharing, memory management, external event, signaling, and memory access. It also reports on the performance results obtained in a set of infrastructures used to check EcP-c, providing clues on the overhead introduced by these mechanisms on limited infrastructures. (c) 2015 Elsevier B.V. All rights reserved.
This paper is concerned with the development of software for embedded systems which will typically be implemented using a small microcontroller (8051, PIc, Hc08 or similar device). It is argued that c remains the most...
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This paper is concerned with the development of software for embedded systems which will typically be implemented using a small microcontroller (8051, PIc, Hc08 or similar device). It is argued that c remains the most appropriate means of developing software for such systems, and guidelines are presented that allow the use of key object-oriented development techniques with this language. Two additional design techniques are also discussed: these are referred to as Project Header and Port Header. An example is used to illustrate the techniques described in the paper.
A computer program has been developed for the Monte carlo simulation of molecular flux impingement on simple spacecraft surfaces due to self- and ambient scattering of outgassing molecules. The outgassing and ambient ...
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A computer program has been developed for the Monte carlo simulation of molecular flux impingement on simple spacecraft surfaces due to self- and ambient scattering of outgassing molecules. The outgassing and ambient molecules are assumed to be elastic spheres with a Maxwellian velocity distribution. Binary elasticcollision processes have been adopted in a hard-sphere collision model. A test-particle Monte carlo methodology is used to simulate sequentially the motions, collisions, and trajectories of the outgassing molecules inside a control volume by means of uniformly distributed random numbers. A unique Monte carlo computational scheme has been developed that reduces the computer processing time by three to four orders of magnitude for a typical outgassing problem without introducing additional assumptions or compromising the solution accuracy. Monte carlo results are obtained in the form of backscatter flux distribution and return flux ratios, for various sample sizes, control-volume sizes, and outgassing and ambient flow conditions. The cPU time for a typical run is about 2 to 4 min on a VAX-8700 computer, and less than about 2 to 4 s on a cray X-MP system.
This paper introduces an optimal scheduling framework for the Earth observation tasks of multiple agile satellites based on nonlinear modeling of attitude change time for the task transition. An attitude control modul...
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This paper introduces an optimal scheduling framework for the Earth observation tasks of multiple agile satellites based on nonlinear modeling of attitude change time for the task transition. An attitude control module using a quaternion feedback constructs the database storing the time to complete the attitude change maneuver for a given initial and final attitude pair. A mixed-integer linear programming (MILP) formulation for optimal satellite task scheduling based on the generated transition time database is developed. The database can accurately estimate the task transition time and ensure the feasibility of the obtained solution. A P-MILP heuristic, which can prune out unnecessary constraints of the original MILP formulation and obtain near-optimal solutions for large problem instances, is proposed. A comprehensive case study on the task scheduling to operate agile satellites validates the proposed framework and heuristic.
We describe a processing program for radioimmunoassay data which uses a log/logit transformation and maximum likelihood estimation to describe mathematically the standard curve, providing a .chi.2 test of goodness of ...
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We describe a processing program for radioimmunoassay data which uses a log/logit transformation and maximum likelihood estimation to describe mathematically the standard curve, providing a .chi.2 test of goodness of fit for the model. Sample values are returned with 95% fiducial probability intervals or standard errors. The program is written in c, which facilitates transportability and modularity.
Verification for OO programs typically starts from a strongly typed object model in which distinct objects/fields are guaranteed not to overlap. This model simplifies verification by eliminating all "uninterestin...
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Verification for OO programs typically starts from a strongly typed object model in which distinct objects/fields are guaranteed not to overlap. This model simplifies verification by eliminating all "uninteresting" aliasing and allowing the use of more efficient frame axioms. Unfortunately, this model is unsound and incomplete for languages like c, where "objects" can overlap almost arbitrarily. Sound verification for c therefore typically starts from an untyped memory model, where memory is just an array of bytes. The untyped model, however, adds substantial annotation burden, and reasoning in the untyped model is computationally expensive. We propose a sound, typed semantics for c that provides the annotational and computational advantages of the typed object model while remaining sound and complete for c. We maintain a predicate identifying where the "valid" objects are, and introduce invariants and proof obligations that guarantee that the valid objects are suitably antialiased, and that (almost) all objects appearing in the program are valid. We describe the implementation of this approach in Vcc (a sound verifier for c being used to verify the Microsoft Hypervisor) and the resulting performance gains.
It is important for personalised e-learning environment to have computational learning status information of individual learners. This article proposes a method to describe syntax-knowledge-point (SKP for short)-based...
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It is important for personalised e-learning environment to have computational learning status information of individual learners. This article proposes a method to describe syntax-knowledge-point (SKP for short)-based learning status of individual learners for personalised cprogramming e-learning environment. This method utilises syntactic knowledge information extracted from c program source code. Firstly, it gathers all offered SKP from example source codes and exercises' model answers in teaching materials;Then, for each learner, it collects his SKP-based learning activities by extracting SKP information from the source code the learner has read or been taught or submitted;Finally, for each learner, his understanding of every SKP can be estimated from the collected data. And individual learners learning status is described by the set of his understanding of each SKP. Experiments show that the proposed method is effective and feasible to get individual learners learning status in detail level by the computer system.
This article presents an empirical study devoted to characterize the computational efficiency behavior of an evolutionary algorithm (usually called canonical) as a c program. The study analyzes the effects of several ...
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This article presents an empirical study devoted to characterize the computational efficiency behavior of an evolutionary algorithm (usually called canonical) as a c program. The study analyzes the effects of several implementation decisions on the execution time of the resulting evolutionary algorithm. The implementation decisions studied include: memory utilization (using dynamic vs. static variables and local vs. global variables), methods for ordering the population, code substitution mechanisms, and the routines for generating pseudorandom numbers within the evolutionary algorithm. The results obtained in the experimental analysis allow us to conclude that significant improvements in efficiency can be gained by applying simple guidelines to best program an evolutionary algorithm in c. copyright (c) 2013 John Wiley & Sons, Ltd.
作者：
camberos, JAWhite, MDUSAF
Res Lab Computat Sci Branch Aeronaut Sci DivAir Vehicles Directorate Wright Patterson AFB OH 45433 USA
Focuses on the portability and scalability of the computational electromagnetics code on massively parallel machines. Theoretical background of Maxwell equations; computer code implementation; Parallel implementation ...
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Focuses on the portability and scalability of the computational electromagnetics code on massively parallel machines. Theoretical background of Maxwell equations; computer code implementation; Parallel implementation and compiling options.
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