Nowadays, most of the research developed by industry and academia has led to several object-oriented methods that are highly adequate for the development of systems, but most of these methods do not include mechanisms...
详细信息
Nowadays, most of the research developed by industry and academia has led to several object-oriented methods that are highly adequate for the development of systems, but most of these methods do not include mechanisms (models) for identifying and specifying user needs and requirements, as well as testing and validating requirements with end users before, during and after development. These considerations are especially important in interactive systems, where the user interaction is very high and the user interface is a significant part of the system. As a result of this weakness, interactive systems developed using such methods can meet all technical requirements, be very robust, and yet be unusable by the end user. This problem explains a large part of the frequently-observed phenomenon whereby large numbers of change requests to modify the services of an application are made after its deployment. As a solution to this problem, we propose a method for integrating a user interface model into the software life-cycle, taking into account user needs and requirements. Also, this approach to the development process ensures the quality of the delivered applications from the end user's point of view.
In this paper, a test-based hardware/software partitioning approach for co-design specifications is presented. The testability of a hierarchical specified co-design system is discussed and an estimate is proposed to e...
详细信息
In this paper, a test-based hardware/software partitioning approach for co-design specifications is presented. The testability of a hierarchical specified co-design system is discussed and an estimate is proposed to evaluate the system testing cost. It depends on the hardware/software testing cost values for each unit-level component. These values are provided by a mutation-test approach applied for testing both software and hardware unit-level implementations. Results have shown that this approach provides a new helpful partitioning criterion which can be used with other already known criteria. A real case study provided by Aerospatiale illustrates this testing cost oriented partitioning.
Continuous Function Charts are a diagrammatical language for the specification of mixed discrete-continuous embedded systems, similar to the languages of Matlab/Simulink, and often used in the domain of transportation...
详细信息
Continuous Function Charts are a diagrammatical language for the specification of mixed discrete-continuous embedded systems, similar to the languages of Matlab/Simulink, and often used in the domain of transportation systems. Both control and dataflows are explicitly specified when atomic units of computation are composed. The obvious way to assess the quality of integration test suites is to compute known coverage metrics for the generated code. This production code does not exhibit those structures that would make it amenable to "relevant" coverage measurements. We define a translation scheme that results in structures relevant for such measurements, apply coverage criteria for both control and dataflows at the level of composition of atomic computational units, and argue for their usefulness on the grounds of detected errors.
For aspect-oriented modular reconfigurable computing, we specify a notion of "aspect" in the context of modular reconfigurable computing systems. In our formal approach, an aspect is determined as a coalgebr...
详细信息
For aspect-oriented modular reconfigurable computing, we specify a notion of "aspect" in the context of modular reconfigurable computing systems. In our formal approach, an aspect is determined as a coalgebraic transformation on modular reconfigurable computing systems. Then, based on this fundamental concept of aspect, inheritance and super- imposition properties of aspects are studied. Specifically, the inheritance property is shown to be a bisimulation relation and the superimposition property is determined in the context of coalgebraic reconfiguration. Moreover, we also justify that our approach is sufficiently expressive to combine aspect-orientation and modular reconfigurable computing.
Considers reconfigurable computing for application-specific systems, with particular reference to mixed-technology chips. A VLIW "core" is augmented by means of reconfigurable functional units (RFUs) and reg...
详细信息
ISBN:
(纸本)0769512062
Considers reconfigurable computing for application-specific systems, with particular reference to mixed-technology chips. A VLIW "core" is augmented by means of reconfigurable functional units (RFUs) and register files implemented via FPGA on to the same chip. The application is analyzed to extract segments of computation that could be usefully collapsed into complex instructions decoded and executed by the RFUs. In this paper, we focus on the problem of selecting the optimum extension to the native instruction set by means of the "best" segments of the computation that will become complex instructions. In particular, a genetic algorithm approach is introduced to analyze the population of candidates; modifications to the classic genetic operators are introduced to take into account the peculiarity of our problem. Applying the proposed methodology to some significant applications has validated the overall approach.
A programmable parallel digital signal processor (DSP) core for embedded applications is presented which combines the concepts of single instruction stream over multiple data streams (SIMD) and reconfigurable architec...
详细信息
ISBN:
(纸本)0769522319
A programmable parallel digital signal processor (DSP) core for embedded applications is presented which combines the concepts of single instruction stream over multiple data streams (SIMD) and reconfigurable architecture. Equipped with eight SIMD-controlled 16-bit datapaths which can also be reconfigured as two 32-bit datapaths, the DSP core can process both 16-bit and 32-bit data in parallel, showing high performance, especially in the applications preferring parallel dataflow computations, such as image processing. The SIMD scheme is extended with the instant-scalability of datapaths (ISSIMD), which offers the DSP a capability of dimension-controllable vector processing, so that to provide flexibility for different embedded applications. A first prototype in 0.18-/spl mu/m CMOS technology has been fabricated, which achieves IGMACS performance at the clock of 125 MHz.
Presently, there are very few visualization systems available for time-dependent flow fields. Although existing visualization systems for instantaneous flow fields may be used to view time-dependent flow fields at dis...
详细信息
ISBN:
(纸本)9780818639401
Presently, there are very few visualization systems available for time-dependent flow fields. Although existing visualization systems for instantaneous flow fields may be used to view time-dependent flow fields at discrete points in time, the time variable is usually not considered in the visualization technique. We present a simple and effective approach for visualizing time-dependent flow fields using streaklines. A system was developed to demonstrate this approach. The system can process many time frames of flow fields without requiring that all the data be in memory simultaneously, and it also handles flow fields with moving grids. We have used the system to visualize streaklines from several large 3-D time-dependent flow fields with moving grids. The system was able to provide useful insights to the physical phenomena in the flow fields.< >
We present an algorithmic analog-to-digital converter (ADC) architecture for large-scale parallel quantization of internally analog variables in externally digital array processors. The converter quantizes and accumul...
详细信息
We present an algorithmic analog-to-digital converter (ADC) architecture for large-scale parallel quantization of internally analog variables in externally digital array processors. The converter quantizes and accumulates a binary weighted sequence of partial binary-binary matrix-vector products computed on the analog array, under presentation of bit-serial inputs in descending binary order. The architecture combines algorithmic conversion of the residue, as in a standard algorithmic ADC, with synchronous accumulation of the partial products from the array. In conjunction with row-parallel digital storage of matrix elements in the array, two pipelined architectures are presented to accumulate partial products with common binary weight across rows: row-parallel ADC with digital post-accumulation, and row-cumulative ADC with analog pre-accumulation. Simulation results are presented to quantify the trade-off in precision and area for full-parallel flash, and row-parallel and row-cumulative partial algorithmic, analog-to-digital conversion on the array.
Program slicing is a technique to identify statements that may influence the computations in other statements. Despite the ongoing research of almost 25 years, program slicing still has problems that prevent a widespr...
详细信息
Program slicing is a technique to identify statements that may influence the computations in other statements. Despite the ongoing research of almost 25 years, program slicing still has problems that prevent a widespread use: Sometimes, slices are too big to understand and too expensive and complicated to be computed for real-life programs. The presented thesis shows solutions to these problems: It contains various approaches which help the user to understand a slice more easily by making it more focused on the user's problem. All of these approaches have been implemented in the VALSOFT system and thorough evaluations of the proposed algorithms are presented. The underlying data structures used for slicing are program dependence graphs. They can also be used for different purposes: A new approach to clone detection based on identifying similar subgraphs in program dependence graphs is presented; it is able to detect modified clones better than other tools. In the theoretical part, this thesis presents a high-precision approach to slice concurrent procedural programs despite the fact that optimal slicing is known to be undecidable. It is the first approach to slice concurrent programs that does not rely on inlining of called procedures.
There is considerable interest in designing guidance systems for UAVs that use passive sensing (such as vision), rather than active sensing which can be bulky, expensive and stealth-compromising. Here we describe an o...
详细信息
There is considerable interest in designing guidance systems for UAVs that use passive sensing (such as vision), rather than active sensing which can be bulky, expensive and stealth-compromising. Here we describe an optical sensor, based partly on principles of insect vision and optic flow analysis, for measurement and control of height above the ground. A video camera is used in conjunction with a specially shaped reflective surface to simplify the computation of optic flow, and extend the range of aircraft speeds over which accurate data can be obtained. The imaging system also provides a useful geometrical remapping of the environment, which facilitates obstacle avoidance and computation of 3-D terrain maps.
暂无评论