Based on the comparative review of several approaches to legacy system conversion and revitalization, the Lyee methodology application for the issue is presented to clarify its idea, the associated procedure, and the implemented tools. It could be said that with the tools and manual developed by ICBSM&T, the mechanical transformation of the conventional program to a Lyee-structured one becomes possible as long as the programs are made in a procedure-oriented language. In addition to the program structure conversion, the Lyee methodology permits people to choose any application language in the transformed program. At the same time, quite a new approach related to the system conversion is introduced, in which the chunk of data extracted from an old program is edited to make a new conventional structure program that has a logical sequence instead of a Lyee type of declarative program. These features can be realized through the concept of LyeeBELT, which is a set of word-information about the attributes, formulae, and conditions for an independent data item.
The overall workflow of the legacy program transformation is shown in the following.
A critical part in its implementation is the feasibility study (pre-analysis) stage where necessary information is supposed to be secured, and an appropriate plan and policy about the system to be revitalized in the new system environment should be clarified so as to customize the tools accordingly. If the initial process is completed, the mechanical legacy system conversion will be realized by registering the parameters in the tool, and the reestablishment of business knowledge in the LyeeBELT will be enabled. With the regulated business logic on the LyeeBELT, the program maintenance afterwards becomes drastically simplified and stable without the ‘spaghetti’ problem, so that software evolution can be possible. 相似文献
Fractal symbolic analysis is a symbolic analysis technique for verifying the legality of program transformations. It is strictly more powerful than dependence analysis; for example, it can be used to verify the legality of blocking LU factorization with pivoting, a task for which dependence analysis is inadequate. In this paper, we show how fractal symbolic analysis can be used to convert between left- and right-looking versions of three kernels of central importance in computational science: triangular solve, Cholesky factorization, and LU factorization with pivoting. 相似文献
Four years of longitudinal data from 373 families participating in a randomized intervention-control clinical trial were used to examine whether intervention effects on adolescent alcohol and tobacco use trajectories were moderated by family risk, as defined by parental social emotional maladjustment. Consistent with earlier outcome evaluations based on analyses of covariance, analyses confirmed that both the Preparing for the Drug Free Years program and the Iowa Strengthening Families Program favorably influenced alcohol use index trajectories across the time frame of the study; only the latter program, however, evidenced positive effects on a tobacco use index. Concerning the primary research question, analyses provided no support for family risk moderation of any intervention effect. Findings indicate the feasibility of developing universal preventive interventions that offer comparable benefits to all families. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
We bridge the gap between compositional evaluators and abstract machines for the lambda-calculus, using closure conversion, transformation into continuation-passing style, and defunctionalization of continuations. This article is a followup of our article at PPDP 2003, where we consider call by name and call by value. Here, however, we consider call by need.We derive a lazy abstract machine from an ordinary call-by-need evaluator that threads a heap of updatable cells. In this resulting abstract machine, the continuation fragment for updating a heap cell naturally appears as an ‘update marker’, an implementation technique that was invented for the Three Instruction Machine and subsequently used to construct lazy variants of Krivine's abstract machine. Tuning the evaluator leads to other implementation techniques such as unboxed values. The correctness of the resulting abstract machines is a corollary of the correctness of the original evaluators and of the program transformations used in the derivation. 相似文献
An improvement for application of Dancoff factor is developed. It combines Stamm'ler's two-term method for resonance integral calculation with neutron current method for Dancoff factor calculation. Stamm'ler's formulation, which is originally derived for the infinite lattice geometry, can be easily revised to contain the Dancoff factor explicitly, while the neutron current method can easily calculate the Dancoff factor for general irregular assembly geometry. For the resonance interference effects the resonance interference factor table is built in pairs of nuclides, only for the interference between 238 U and other resonance nuclides, spanning over a range of background cross-section and number density ratio of the pairing nuclides. A series of verification calculations have been carried out for problems of infinite lattice and single assembly geometry, with two or multiple resonance absorbers. For these verification calculations, our improvement on Dancoff factor application and resonance interference give good results. 相似文献
A concern can be characterized as a developer׳s intent behind a piece of code, often not explicitly captured in it. We discuss a technique of recording concerns using source code annotations (concern annotations). Using two studies and two controlled experiments, we seek to answer the following 3 research questions: (1) Do programmers׳ mental models overlap? (2) How do developers use shared concern annotations when they are available? (3) Does using annotations created by others improve program comprehension and maintenance correctness, time and confidence? The first study shows that developers׳ mental models, recorded using concern annotations, overlap and thus can be shared. The second study shows that shared concern annotations can be used during program comprehension for the following purposes: hypotheses confirmation, feature location, obtaining new knowledge, finding relationships and maintenance notes. The first controlled experiment with students showed that the presence of annotations significantly reduced program comprehension and maintenance time by 34%. The second controlled experiment was a differentiated replication of the first one, focused on industrial developers. It showed a 33% significant improvement in correctness. We conclude that concern annotations are a viable way to share developers׳ thoughts. 相似文献
In this paper we have obtained, following Craig's procedure, a simplified form for the ASN of a single sampling plan under curtailment arising from observation of enough nondefectives to accept a lot or enough defectives to reject a lot. 相似文献