bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dissipativity and stability of interconnections
Authors: Willems Jan C. , Takaba Kiyotsugu 
Published: November 2006

AbstractA new definition of dissipativity is proposed. It is purely in terms of the rate of supply that goes in and out of a dynamical system. It is proven that dissipativity is equivalent to the existence of a non‐negative storage. Several results regarding the dissipativity of systems defined by quadratic differential forms are given, and some open questions are mentioned. These ideas are applied to the question of stability of interconnected systems. Copyright © 2006 John Wiley & Sons, Ltd.
A random‐effects Markov transition model for Poisson‐distributed repeated measures with non‐ignorable missing values
Authors: Li Jinhui , Yang Xiaowei , Wu Yingnian , Shoptaw Steven 
Published: November 2006

AbstractIn biomedical research with longitudinal designs, missing values due to intermittent non‐response or premature withdrawal are usually ‘non‐ignorable’ in the sense that unobserved values are related to the patterns of missingness. By drawing the framework of a shared‐parameter mechanism, the process yielding the repeated count measures and the process yielding missing values can be modelled separately, conditionally on a group of shared parameters. For chronic diseases, Markov transition models can be used to study the transitional features of the pathologic processes. In this paper, Markov Chain Monte Carlo algorithms are developed to fit a random‐effects Markov transition model for incomplete count repeated measures, within which random effects are shared by the counting process and the missing‐data mechanism. Assuming a Poisson distribution for the count measures, the transition probabilities are estimated using a Poisson regression model. The missingness mechanism is modelled with a multinomial‐logit regression to calculate the transition probabilities of the missingness indicators. The method is demonstrated using both simulated data sets and a practical data set from a smoking cessation clinical trial. Copyright © 2006 John Wiley & Sons, Ltd.
The statistical performance of an MCF‐7 cell culture assay evaluated using generalized linear mixed models and a score test
Authors: Rey deCastro B. , Neuberg Donna 
Published: November 2006

AbstractBiological assays often utilize experimental designs where observations are replicated at multiple levels, and where each level represents a separate component of the assay's overall variance. Statistical analysis of such data usually ignores these design effects, whereas more sophisticated methods would improve the statistical power of assays. This report evaluates the statistical performance of an in vitro MCF‐7 cell proliferation assay (E‐SCREEN) by identifying the optimal generalized linear mixed model (GLMM) that accurately represents the assay's experimental design and variance components. Our statistical assessment found that 17β‐oestradiol cell culture assay data were best modelled with a GLMM configured with a reciprocal link function, a gamma error distribution, and three sources of design variation: plate‐to‐plate; well‐to‐well, and the interaction between plate‐to‐plate variation and dose. The gamma‐distributed random error of the assay was estimated to have a coefficient of variation (COV) = 3.2 per cent, and a variance component score test described by X. Lin found that each of the three variance components were statistically significant. The optimal GLMM also confirmed the estrogenicity of five weakly oestrogenic polychlorinated biphenyls (PCBs 17, 49, 66, 74, and 128). Based on information criteria, the optimal gamma GLMM consistently out‐performed equivalent naive normal and log‐normal linear models, both with and without random effects terms. Because the gamma GLMM was by far the best model on conceptual and empirical grounds, and requires only trivially more effort to use, we encourage its use and suggest that naive models be avoided when possible. Copyright © 2006 John Wiley & Sons, Ltd.
In Situ Organization of Gold Nanorods on Mixed Self‐Assembled‐Monolayer Substrates
Authors: Zareie M. Hadi , Xu Xiaoda , Cortie Michael B. 
Published: November 2006

AbstractA method is described for assembling gold nanorods, end‐to‐end, into long chains attached on top of a mixed self‐assembled monolayer that has been functionalized with streptavidin. Methods to prepare chains of nanorods in colloidal suspension have been reported by others, but our protocol offers a way to directly form such structures on a substrate. The rods are spaced ≈5 nm apart in the resulting chains, which extend for over a micrometer in length. The assembly and morphology of the nanorod structures were characterized by surface plasmon resonance spectroscopy, as well as by scanning electron microscopy and scanning probe microscopy. Structures of this type could conceivably serve as plasmonic waveguides in future nanodevices.
Uncertainty in computer application and its control through the engineering of software
Authors: Lehman M. M. 
Published: November 2006

AbstractComputers are being applied more and more broadly to address applications in all areas of human activity, penetrating ever deeper into the very fabric of society. As a consequence, mankind is becoming, collectively and individually, ever more dependent on software and on the integrity of that software. In this context the term software includes both the systems software that constitutes a fundamental part of the operational configuration and the programs that implement each individual application. Integrity is a many faceted concept that has to do with the availability of programs whenever they are needed and their correctness in relation to the circumstances at the moment of execution or, more precisely, when the results of computation are applied. A program must produce a solution that is correct and relevant when used. It must continue to do so whenever required over the lifetime of an application and of the systems that realize and support it. All this is required despite continuing change in a dynamic world.This paper discusses some properties of software and of software technology and identifies fundamental issues that must be addressed if program integrity is to be achieved initially, and if a program is to be maintained as satisfactory in a continuously changing operational environment. The discussion leads to formulation of a ‘Principle of Uncertainty’ that applies, in general, to all computer applications in the real world.The principle follows from the fact that any program is a model, albeit many times removed by abstraction and reification from the real world it reflects and addresses. The consequences of this basic fact lead to a need for a disciplined technology associated with a controlled process for definition of each application, its operational domain, the envisaged system and software, and for its development, application and evolution (maintenance).This paper concludes with a brief mention of the implications of the analysis on relevant technological issues. Fundamental concepts and observations that underlie the development of a software engineering discipline and its supporting technology are introduced. Software engineering is seen as the discipline that permits one to limit uncertainty and its consequences through the introduction and control of appropriate development processes and the systematic and disciplined applications of methods and tools. The emergence of such tools, of computer assisted software engineering (CASE) and of programming and project support environments (IPSEs) is briefly discussed. Finally the paper addresses issues that arise in transferring this still developing technology to industry and introducing it into practice, outlining briefly how this may be approached.
Organizational foundations for maintenance
Authors: Swanson E. B. , Beath C. M. 
Published: November 2006

AbstractMaintaining application software for information systems in organizations poses managerial problems. Among these are: How should maintenance be planned? How should the maintenance staff be organized? What information is needed to manage maintenance? In a recent field study, in which we developed twelve cases, we explored the answers to these and other related questions. We found that organizational issues in maintenance may be comprehended in terms of a Relational Foundations Model involving the application systems, the IS staff and the system users. Vignettes from the cases illustrate. A new, organizational view of maintenance is suggested, one which departs from the traditional view of maintenance as a technical, individual programming task.
Dynamic program updating: A software maintenance technique for minimizing software, downtime
Authors: Segal M. E. , Frieder O. 
Published: November 2006

AbstractWhen a new version of a software system is created, the current version of the system must be shut down while the new version is installed, resulting in software ‘downtime’. There are application domains where such downtime is undesirable if not wholly unacceptable. A dynamic program updating system replaces, or updates, a computer program with a new version while the program continues to run. A dynamic program updating system for programs written in conventional procedural languages such as Pascal and C is described. The proposed system updates programs without causing substantial performance degradation and requires minimal user intervention to initiate the update. A fully functional prototype updating system is presented and a sample program, namely an internet packet router called the ‘Packet Pumper’, is updated. The performance of the updating system and the Packet Pumper is discussed.
Lurking within COBOL PERFORMs
Authors: Crawford M. A. 
Published: November 2006

AbstractCOBOL‐implemented systems commonly rely on the PERFORM verb to provide structure and iteration in the software. Because of that key role, shortfalls in the use of PERFORM can lead to challenging difficulties in both enhancive and corrective maintenance. This paper explains the source of many of the symptoms by examining the way the compiler‐generated object code executes. Then it classifies the symptoms by their pattern and relates the classes to the normally hidden generated code. In closing, the paper offers six positive actions to improve COBOL software using the PERFORM verb, and points to their contribution in enhancive and corrective maintenance, software quality assurance, systems improvement, and the management of software maintenance.
Software metrics and software maintenance
Authors: Leach Ronald J. 
Published: November 2006

AbstractThe term “software crisis” refers to the huge amount of resources needed for the development and maintenance of software. A major problem with research in these areas is the lack of solid data. In particular, there is little data that can be used to predict the types of problems that are likely to occur during the software's maintenance.This paper describes the results of an analysis of a software system that underwent several revisions. Maintenance of the system was performed by distinct programming teams. At each revision of the software system, the analysis was performed by doing measurements of module complexity based on three quantities: Halstead's Software Science Effort, McCabe's cyclomatic complexity, and coupling analyses. The relationships of Software Science Effort to unchangeability of modules, of cyclomatic complexity to path coverage, and coupling analysis to measurement of modularity and coherence during the maintenance are given.
Problems of maintenance of JSP structures
Authors: Davies C. G. 
Published: November 2006

AbstractA JSP oriented program design environment has been produced at UMIST (known as MAJIC), which computerizes the whole of the JSP methodology. This computerization of JSP has shown some shortcomings of the method with regard to the maintenance of the finished programs. The method imposes restrictions on the modification of program and data structures which reduces the effectiveness of using the method to maintain existing structures. This paper investigates some of those restrictions in the light of the work done to produce the MAJIC system. The restrictions are centred on the JSP mechanism for data structure correspondences, which are crucial to the use of JSP. Rules are proposed by which controlled modifications may be made to Jackson structures without, as is otherwise the case, of the need to reprocess large parts of the method. The rules were made in order to make a tool based on JSP more flexible, but they may equally be applied to maintenance of structures produced manually.
Characteristics of empirical software maintenance studies: 1980–1989
Authors: Sharpe Shane , Haworth Dwight A. , Hale David 
Published: November 2006

AbstractThis study examines empirical software maintenance research during the decade of the 1980s and categorizes the research according to placement, origin, and nature of research to determine what has been done in the past. To aid in the investigation, an exhaustive electronic keyword search was made of abstracts found in Computer Database Abstracts and INSPEC's Computer and Control Abstracts. Once candidate articles were identified, their full abstracts were scrutinized to determine whether the entire article should be reviewed. Based on a review of the full articles, summary statistics and research trends were established for software maintenance research published during the decade of the 1980s. The discussion that follows is partially based on an interpretation of the findings by an expert panel of information systems professionals actively working in the software maintenance area or engaged in management activities associated with software maintenance. Conclusions concerning the form and direction of future software maintenance publications are then advanced.
Decision‐based software development
Authors: Wild Chris , Maly Kurt , Liu Lianfang 
Published: November 2006

AbstractCurrent software development paradigms focus on the products of the development process. Much of the decision‐making process which produces these products is outside the scope of these paradigms. The decision‐based software development (DBSD) paradigm views the design process as a series of interrelated decisions which involve the identification and articulation of problems, alternatives, solutions and justifications. Decisions made by programmers and analysts are recorded in a project database. Unresolved problems are also recorded and resources for their resolution are allocated by management according to the overall development strategy. This decision structure is linked to the products affected by the relevant decisions and provides a process‐oriented view of the resulting system. Software maintenance uses this decision view of the system to understand the rationale behind the decisions affecting the part of the system to be modified. The relationships between decisions help assess the impact of changing one or more decisions. We describe D‐HyperCase, a prototype Decision‐Based Hypermedia System and give results of applying the DBSD approach during its development.
Predicting maintainability with software quality metrics
Authors: Henry Sallie , Wake Steve 
Published: November 2006

AbstractMaintenance of software makes up a large fraction of the time and money spent in the software life‐cycle. By reducing the need for maintenance these costs can also be reduced. Predicting where maintenance is likely to occur can help to reduce maintenance by prevention. In this paper, maintenance is defined as correction of errors in the program. This paper details a study of the use of software quality metrics to determine high‐complexity components in a software system. By the use of a history of maintenance done on a particular system, it is shown that a predictor equation can be developed to identify components which needed maintenance activities. This same equation can also be used to determine which components are likely to need maintenance in the future. Through the use of these predictions and software metric complexities, it should be possible to reduce the likelihood of a component needing maintenance. This might be accomplished by reducing the complexity of that component through further decomposition. Even though this is only one study, this methodology of developing maintenance predictors could be applied in any environment.
Economics of software re‐engineering
Authors: Sneed Harry M. 
Published: November 2006

AbstractThere is a pressing need to be able to calculate and to justify the costs of software re‐engineering. The purpose of the paper is to address that need by establishing a framework for the economics of re‐engineering. The objective of re‐engineering is to reduce maintenance costs. This objective is served by increasing quality and reducing complexity. Both of these goals are examined here in the light of software maintainability metrics. The costs of re‐engineering are driven by the size and interdependency of the software as well as by the degree of automation available. The paper presents a method of estimating the costs of re‐engineering, and presents some figures acquired through practical experience. Finally, a method is defined for weighing estimated costs against expected benefits in order to support decisions on whether to renovate existing software or replace it by a new development. This is a major decision faced by many industrial managers today.
The role of symbolic execution in software maintenance
Authors: Coward P. D. , Ince D. C. 
Published: November 2006

AbstractTwo major problems facing the software maintenance programmer are avoiding the introduction of unexecutable code and coping with the large volume of regression tests that are often required during maintenance. In preparing program changes, staff who carry out maintenance often have to spend time on ascertaining the constraints which govern the variables at the proposed points of insertion of the new code. This effort is required to avoid the introduction of unexecutable code which can so easily happen when maintenance staff are unaware of the prevailing constraints. This often means that many of the paths executed during regression testing are executed more than once in an attempt to overcome the risk of coincidental correctness camouflaging an error. This paper describes how symbolic execution, and in particular the SYM‐BOL system, can be used to reduce the likelihood of introducing unexecutable code, to speed up the process of determining the constraints on variables at a given point in a program and to reduce the volume of regression testing.
Design metrics and software maintainability: An experimental investigation
Authors: Shepperd Martin , Ince Darrel 
Published: November 2006

AbstractAn empirical study was conducted into the relationship between various design metrics and software maintainability. This was based upon maintenance changes made to four different versions of a project management tool carried out by a total of 60 programmers. The overall conclusion from the investigation, was that accurate prediction of quality characteristics for single maintenance changes is extremely difficult. This is due to the many sources of variation—principally change type and programmer ability. Nevertheless, we show that measures of information flow local to specific modifications are significantly related to error rates, with a 600% greater probability of a residual error as a consequence of a change in a module with a high level of information flow‐based coupling, than a module with a low level of coupling. Furthermore, we show that different types of change reveal marked variations in their relationships with the design metrics. Consequently, we argue that using robust statistical techniques and theoretically well‐founded design metrics, engineering approximations are possible.
A conceptual design for a code analysis knowledge base
Authors: Dietrich Suzanne W. , Calliss Frank W. 
Published: November 2006

AbstractA knowledge base system for inter‐module code analysis is presented. Inter‐module code analysis is a technique that a programmer can use to analyse programs written in languages that contain a clustering construct called a module (or package). A module allows a programmer to control the visibility of a component within a program. The knowledge base for inter‐module code analysis is designed using the enhanced entity‐relationship conceptual data model, which is a graphical representation of the data and its relationships. The conceptual design for a code analysis enterprise is mapped into a knowledge base system, which uses a declarative logic‐based language to represent data as both facts and rules. The use of this knowledge base in an inter‐module code analysis application is demonstrated.
Reverse‐engineering and intermodular data flow: A theoretical approach
Authors: Canfora G. , Cimitile A. 
Published: November 2006

AbstractStarting from the need for formalization and models to represent and repeat reverse‐engineering activities, this paper presents a proposal in the field of data flow analysis. In particular, the authors propose a formal model for a practical approach to the reconstruction of intermodular data flow associated with the structure charts of a Pascal software system. Specific matrices extracted straight from code are presented and matrix calculation is then exploited to obtain a final matrix containing all the information needed for the reconstruction of the data flow. Finally, this flow is reconstructed by means of transformations on the elements in this matrix.
Athena: A software measurement and metrics environment
Authors: Tsalidis C. , Christodoulakis D. , Maritsas D. 
Published: November 2006

AbstractATHENA is a parametrizable software tool oriented towards the measurement of software quality characteristics. Measurement is based on the syntax and semantic (graph‐based) analysis of programs. ATHENA is language‐independent and customizable, i.e. language specifications as well as measurement algorithms are input to the tool which automatically generates the measurement environment for the corresponding language. Currently ATHENA has the ability to support Pascal, ADA and C and offers the possibility of measuring a set of kernel metrics (e.g. Halstead's ‘Software Complexity Measure’, McCabe's ‘Cyclomatic Complexity Metric’, Tai's ‘Data Flow Complexity Measure’ etc.). A specially designed specification language allows for easy implementation of design and code metrics. This is one of the reasons that ATHENA is particularly useful for software maintainability control.