Correction Effort Research Articles

Application of a hydrometeorological model chain to investigate the effect of global boundaries and downscaling on simulated river discharge

In the current study, two regional climate models (MM5 and REMO) driven by different global boundary conditions (the ERA40 reanalysis and the ECHAM5 model) are one-way coupled to the uncalibrated hydrological process model PROMET to analyze the impact of global boundary conditions, dynamical regionalization and subsequent statistical downscaling (bilinear interpolation, correction of subgrid-scale variability and combined correction of subgrid-scale variability and bias) on river discharge simulation. The results of 12 one-way coupled model runs, set up for the catchment of the Upper Danube (Central Europe) over the historical period 1971–2000, prove the expectation that the global boundaries applied to force the RCMs strongly influence the accuracy of simulated river discharge. It is, however, noteworthy that all efficiency criteria in case of bias corrected MM5 simulations indicate better performance under ERA40 boundaries, whereas REMO-driven hydrological simulations better correspond to measured discharge under ECHAM5 boundaries. Comparing the hydrological results achievable with MM5 and REMO, the application of bias-corrected MM5 simulations turned out to allow for a more accurate simulation of discharge, while the variance in simulated discharge in most cases was better reflected in case of REMO forcings. The correction of subgrid-scale variability within the downscaling of RCM simulations compared to a bilinear interpolation allows for a more accurate simulation of discharge for all model configurations and all discharge criteria considered (mean monthly discharge, mean monthly low-flow and peak-flow discharge). Further improvements in the hydrological simulations could be achieved by eliminating the biases (in terms of deviations from observed meteorological conditions) inherent in the driving RCM simulations, regardless of the global boundary conditions or the RCM applied. In spite of all downscaling and bias correction efforts described, the RCM-driven hydrological simulations remain less accurate than those achievable with spatially distributed meteorological observations.

Increased risk of fatal infections in women starting peritoneal dialysis.

Although cardiovascular disease (CVD) is an important cause of morbidity and mortality in patients with end-stage renal disease, non-CVD causes account for more than 50% of total deaths. We previously showed that, compared with men, women starting dialysis-- both hemodialysis and peritoneal dialysis (PD)--have higher non-CVD mortality rates. Here, we evaluate sex-specific outcomes in a large cohort of incident PD patients. Incident de novo PD patients from the Andalusian SICATA Registry for 1999 - 2010, with follow-up until 31 December 2010 or up to 5 years, were investigated for fatal outcomes. Causes of death were extracted from medical records. The analysis used traditional and competing-risk Cox models for all-cause and cause-specific mortality in men and women, correcting in the competing-risk models for the events of kidney transplantation and transfer to hemodialysis. A total of 1458 patients (57% men; mean overall age: 55.3 ± 17.0 years) initiated PD in Andalusia during the study period. During follow-up, 350 deaths, 355 renal transplantation procedures, and 331 transfers to hemodialysis were recorded. Vascular disease and diabetic nephropathy were the most frequent causes of kidney failure in men; other causes were more common in women. In the traditional Cox model, both sexes showed a similar all-cause mortality risk [crude hazard ratio (HR): 0.90; 95% confidence interval (CI): 0.72 to 1.12]. However, with respect to specific causes of death, women showed a borderline lower risk of both CVD (crude HR: 0.71; 95% CI: 0.50 to 0.99) and non-CVD mortality from other than infection (crude HR: 0.81; 95% CI: 0.57 to 1.15). In contrast, the risk of death from infection was almost doubled in women compared with men (crude HR: 1.92; 95% CI: 1.15 to 3.20), a finding that held true after multivariate adjustment for age, primary renal disease, period of inclusion, and initial PD modality (adjusted HR: 1.76; 95% CI: 1.03 to 3.01). This result was confirmed even taking into consideration the competing events of kidney transplantation and transfer to hemodialysis. Compared with men starting PD, women starting PD are at higher risk of mortality from infection. More stringent screening measures and corrective efforts in women might be indicated.

Predictive models in software engineering

Welcome to the Empirical Software Engineering’s special issue on predictive models in software engineering. The goal of such methods is repeatable, refutable (and possibly improvable) results in software engineering. Many of the recent papers in SE literature are based on data from on-line repositories such as http://promisedata.googlecode.com. This introduces a kind of selection in the kinds of papers published at this venue. Our first paper pushes past that bias to explore a very rich time-based data set. In “Predicting the Flow of Defect Correction Effort using a Bayesian Network Model”, Schulz et al. use a Bayes net to explore the effects of removing defects at different stages of the software lifecycle. Their work shows how to calibrate general models to the particulars of a company’s local particulars. Our next paper “The Limited Impact of Individual Developer Data on Software Defect Prediction” by Bell et concludes there is no added value to reasoning on some aspects of social aspects of programmer teams working on a code. This is a timely counterpoint to other research that eschews code measures for other approaches based only on social metrics. Our last paper explores the complicated issue of parameter tuning. In “Using Tabu Search to Configure Support Vector Regression for Effort Estimation”, Corazza et al. offers automated guidance for setting the parameters that control a learner. This is a matter of critical importance since even the best learner can perform poorly if its operator uses the wrong settings. A special issue like this is only possible due to the hard work of a dedicated set of authors are reviewers. We would like to express our gratitude to all authors who submitted their papers this special issue. We would also like to thank our reviewers for their meticulous evaluation of the submissions. The success of special issues such as this one largely stands on their shoulders. Empir Software Eng (2013) 18:433–434 DOI 10.1007/s10664-013-9252-1

Extended Matrix and Inverse Matrix Methods Utilizing Internal Validation Data When Both Disease and Exposure Status Are Misclassified.

The problem of misclassification is common in epidemiological and clinical research. In some cases, misclassification may be incurred when measuring both exposure and outcome variables. It is well known that validity of analytic results (e.g. point and confidence interval estimates for odds ratios of interest) can be forfeited when no correction effort is made. Therefore, valid and accessible methods with which to deal with these issues remain in high demand. Here, we elucidate extensions of well-studied methods in order to facilitate misclassification adjustment when a binary outcome and binary exposure variable are both subject to misclassification. By formulating generalizations of assumptions underlying well-studied "matrix" and "inverse matrix" methods into the framework of maximum likelihood, our approach allows the flexible modeling of a richer set of misclassification mechanisms when adequate internal validation data are available. The value of our extensions and a strong case for the internal validation design are demonstrated by means of simulations and analysis of bacterial vaginosis and trichomoniasis data from the HIV Epidemiology Research Study.

Under-Prescribing and Non-Adherence to Medications after Coronary Bypass Surgery in Older Adults

The focus for this clinical review is under-prescribing and non-adherence to medication guidelines in older adults after coronary artery bypass grafting (CABG) surgery. Non-adherence occurs in all age groups, but older adults have a unique set of challenges including difficulty hearing, comprehending, and remembering instructions; acquiring and managing multiple medications; and tolerating drug-drug and drug-disease interactions. Still, non-adherence leads to increased morbidity, mortality, and costs to the healthcare system. Factors contributing to non-adherence include failure to initiate therapy before hospital discharge; poor education about the importance of each medication by hospital staff; poor education about medication side effects; polypharmacy; multiple daily dosing; excessive cost; and the physician's lack of knowledge of clinical indicators for use of medications. To improve adherence, healthcare systems must ensure that (i) all patients are prescribed the appropriate medications at discharge; (ii) patients fill and take these medications post-operatively; and (iii) patients continue long-term use of these medications. Interventions must target central administrative policies within healthcare institutions, the difficulties facing providers, as well as the concerns of patients. Corrective efforts need to be started early during the hospitalization and involve practitioners who can follow patients after the date on which surgical care is no longer needed. A solid, ongoing relationship between patients and their primary-care physicians and cardiologists is essential. This review summarizes the post-operative medication guidelines for CABG surgery, describes barriers that limit the adherence to these guidelines, and suggests possible avenues to improve medication adherence in older cardiac surgery patients.

Maintainability defects detection and correction: a multi-objective approach

Software defects often lead to bugs, runtime errors and software maintenance difficulties. They should be systematically prevented, found, removed or fixed all along the software lifecycle. However, detecting and fixing these defects is still, to some extent, a difficult, time-consuming and manual process. In this paper, we propose a two-step automated approach to detect and then to correct various types of maintainability defects in source code. Using Genetic Programming, our approach allows automatic generation of rules to detect defects, thus relieving the designer from a fastidious manual rule definition task. Then, we correct the detected defects while minimizing the correction effort. A correction solution is defined as the combination of refactoring operations that should maximize as much as possible the number of corrected defects with minimal code modification effort. We use the Non-dominated Sorting Genetic Algorithm (NSGA-II) to find the best compromise. For six open source projects, we succeeded in detecting the majority of known defects, and the proposed corrections fixed most of them with minimal effort.

Predicting the Flow of Defect Correction Effort using a Bayesian Network Model

The number of defects alone does not provide software companies with enough information on the effort required to fix them. Defects have different impacts on the overall defect correction effort – defects introduced in one phase may be found and corrected in the same or later phase. The later they are found, the more effort is required to correct them. The main aim of this paper is to build and validate a model (Bayesian Network) for predicting the defect correction effort at various phases of the software development process. The procedure of building the model covers the following steps: problem analysis, data analysis, model definition and enhancement, simulation runs, and model validation. Developed Defect Cost Flow Model (DCFM), which is an implementation of the V-model of a software project lifecycle, correctly incorporates known qualitative and quantitative relationships. Application of DCFM in a real industrial process revealed its high potential in finding the appropriate amount of review effort for specific development phases to minimize the overall costs. The model may be used in the industry for decision support. It can be extended and calibrated to meet the needs of specific development environment.

Artful Dodgers: Reconceiving the Golden Age of Children's Literature (review)

Reviewed by: Artful Dodgers: Reconceiving the Golden Age of Children's Literature Martha P. Hixon (bio) Artful Dodgers: Reconceiving the Golden Age of Children's Literature. By Marah Gubar. Oxford and New York: Oxford University Press, 2009. Conventional critical wisdom has long held that the Victorians were wedded to the Romantic idea of the inherent innocence of children and other "primitives" and that, consequently, Victorian writers often incorporated an idealized child in their works, a child that must be forever isolated from the "real" adult world in order to remain pure and incorrupt. Children's literature critics in the late 1980s and early 1990s applied this theory of the "cult of the child" to Victorian children's authors as well, advancing various arguments regarding how Lewis Carroll, J. M. Barrie, Francis Hodgson Burnett, and their contemporaries not only perpetuated this ideal in their child characters but also attempted to coerce their child readers into conforming to that naïve ideal. The account put forth by these critics held that these authors conceived of childhood, both in fiction and outside of it, as a nostalgic place of escape from the anxieties and uncertainties of adulthood, and that they tried their best to maintain that innocence both within and through the books they produced for children. Gubar's book is a refreshing answer to this simplistic thinking. Gubar unabashedly takes on Jacqueline Rose, James Kincaid, Humphrey Carpenter, Jackie Wullschläger, and others, presenting an incisive, wide-ranging, and grounded argument that writers of the Golden Age of children's literature were "far more skeptical about Romantic primitivism than this account suggests," and that "on the contrary, they generally conceive[d] of child characters and child readers as socially saturated beings, profoundly shaped by the culture, manner, and morals of their time" (4). Gubar does not reject the "cult of the child" paradigm outright, conceding that idealization of children did indeed exist in Victorian thinking, but she contends that the critical assessment regarding Golden Age literature "must be reconceived to reflect the fact that … the Victorians and Edwardians frequently manifested a high level of critical self-consciousness about the whole problem of representing, writing for, looking at, interacting with, and worshipping children" (viii), and they were vitally concerned with the power imbalances inherent in the relationship between adult author and child reader. Artful Dodgers is a strong first salvo in the corrective effort that Gubar calls for, an exploration of the ways in which these authors more often than not posited fictive situations that examined how adult-child interactions could promote agency for [End Page 240] their child characters (and thus, the readers who identified with them). The "artful dodgers" of her title are those children who are savvy enough to effectively collaborate with the adult world into which they are born rather than live in glorified isolation from it. Following an introduction that lays the groundwork for her new reading of Golden Age literature along the lines noted above, Gubar organizes her argument into six chapters. Chapter 1, "The Rise of the Child Narrator," considers the ways in which early Victorian authors for children utilized child narrators in their texts. Gubar notes this area has "received virtually no critical attention" (39) because scholars have overlooked the experimentation of women writers early in the century, focusing instead on Dickens's Holiday Romance (1868) and E. Nesbit's The Story of the Treasure Seekers (1899) as the period's examples of adult appropriation of the child's voice to tell the story. Such selectivity, Gubar observes, leads to generalized conclusions regarding the overt and covert colonization of children by the Victorian authors who wrote for them, a view that Gubar demonstrates is undercut by Juliana Ewing, Maria Molesworth, Diana Craik, and even Nesbit herself, all of whom routinely assumed their child readers were able to recognize and resist underlying didactic messages in books and who utilized child narrators that their readers would both sympathize with and critique rather than wholeheartedly embrace and emulate. Chapter 2 focuses on Robert Louis Stevenson's Treasure Island as an "anti-adventure story" rather than an imperialist text that adheres to the Robinsonade paradigm celebrated by popular adventure story...

Evaluation of a Mandatory Quality Assurance Data Capture in Anesthesia

Efforts to assure high-quality, safe, clinical care depend upon capturing information about near-miss and adverse outcome events. Inconsistent or unreliable information capture, especially for infrequent events, compromises attempts to analyze events in quantitative terms, understand their implications, and assess corrective efforts. To enhance reporting, we developed a secure, electronic, mandatory system for reporting quality assurance data linked to our electronic anesthesia record. We used the capabilities of our anesthesia information management system (AIMS) in conjunction with internally developed, secure, intranet-based, Web application software. The application is implemented with a backend allowing robust data storage, retrieval, data analysis, and reporting capabilities. We customized a feature within the AIMS software to create a hard stop in the documentation workflow before the end of anesthesia care time stamp for every case. The software forces the anesthesia provider to access the separate quality assurance data collection program, which provides a checklist for targeted clinical events and a free text option. After completing the event collection program, the software automatically returns the clinician to the AIMS to finalize the anesthesia record. The number of events captured by the departmental quality assurance office increased by 92% (95% confidence interval [CI] 60.4%-130%) after system implementation. The major contributor to this increase was the new electronic system. This increase has been sustained over the initial 12 full months after implementation. Under our reporting criteria, the overall rate of clinical events reported by any method was 471 events out of 55,382 cases or 0.85% (95% CI 0.78% to 0.93%). The new system collected 67% of these events (95% confidence interval 63%-71%). We demonstrate the implementation in an academic anesthesia department of a secure clinical event reporting system linked to an AIMS. The system enforces entry of quality assurance information (either no clinical event or notification of a clinical event). System implementation resulted in capturing nearly twice the number of events at a relatively steady case load.

Characteristics of multiple-component defects and architectural hotspots: a large system case study

The architecture of a large software system is widely considered important for such reasons as: providing a common goal to the stakeholders in realising the envisaged system; helping to organise the various development teams; and capturing foundational design decisions early in the development. Studies have shown that defects originating in system architectures can consume twice as much correction effort as that for other defects. Clearly, then, scientific studies on architectural defects are important for their improved treatment and prevention. Previous research has focused on the extent of architectural defects in software systems. For this paper, we were motivated to ask the following two complementary questions in a case study: (i) How do multiple-component defects (MCDs)--which are of architectural importance--differ from other types of defects in terms of (a) complexity and (b) persistence across development phases and releases? and (ii) How do highly MCD-concentrated components (the so called, architectural hotspots) differ from other types of components in terms of their (a) interrelationships and (b) persistence across development phases and releases? Results indicate that MCDs are complex to fix and are persistent across phases and releases. In comparison to a non-MCD, a MCD requires over 20 times more changes to fix it and is 6 to 8 times more likely to cross a phase or a release. These findings have implications for defect detection and correction. Results also show that 20% of the subject system's components contain over 80% of the MCDs and that these components are 2---3 times more likely to persist across multiple system releases than other components in the system. Such MCD-concentrated components constitute architectural "hotspots" which management can focus upon for preventive maintenance and architectural quality improvement. The findings described are from an empirical study of a large legacy software system of size over 20 million lines of code and age over 17 years.

National Security Secrecy: How the Limits Change

As a nation, we seem to be of two minds about secrecy. We know that government secrecy is incompatible with democratic decision-making in obvious ways. Yet there is a near-universal consensus that some measure of secrecy is justified and necessary to protect authorized national security activities. Reconciling these conflicting interests is an ongoing challenge. In recent years, a large and growing number of public interest organizations and professional societies have turned their attention to government secrecy, identifying it as an obstacle to achieving their own objectives. These professionally and politically diverse groups are united by the perception that secrecy has escalated to the point of dysfunction. On that point, there is not much disagreement. One basic premise of the critics of government secrecy is that too much information gets classified and withheld from the public in the name of national security, and that this has undesirable effects on public policy and on public discourse. But a second basic premise is that it is possible to do something about that. These organizations, including my own, do not simply want to protest against improper secrecy but to correct it. And to a remarkable extent, the secrecy system lends itself to such corrective efforts through various mechanisms that will be described below.

Retracted: Correction or comparison? The effects of prime awareness on social judgments

AbstractIn previous research on the effects of accessible information on social judgments, divergent explanations have been offered for contrast effects that occur as a consequence of prime awareness. Some authors favor a comparison explanation, whereas others favor a correction explanation. In two studies, we successfully disentangled comparison and correction contrast by demonstrating that whereas correction for unwanted influences is a general process that leads to contrast on various dimensions on which a target is judged, comparison effects are prime specific and occur mainly on comparison relevant dimensions. In addition, our findings indicate that for correction attempts to occur and succeed, respondents must have the feeling that these primes contaminate their target judgments and should be removed from their “true” reaction to the target. When people are not suspicious of the potential contaminating influences of priming stimuli, prime awareness is more likely to lead to prime‐target comparisons than to correction efforts. Copyright © 2009 John Wiley & Sons, Ltd.

Self-medication with antibiotics in the ambulatory care setting within the Euro-Mediterranean region; results from the ARMed project

Anecdotal data from the southern and eastern Mediterranean region suggests that self-medication with antibiotics is commonly practiced in many countries. In order to provide proper information on the situation, we undertook short structured interviews in out-patients clinics or primary health centres in Cyprus, Egypt, Jordan, Lebanon, Libya, Tunisia and Turkey. A total of 2109 interviews were undertaken of which 1705 completed the full questionnaire. Self-medication was reported by 19.1% (<0.1% in Cyprus to 37% in Lebanon) of respondents. Intended self-medication ranged from 1.3% (95% CI 0%, 3%) in Cyprus to 70.7% (95% CI 64%, 77%) in Jordan. Upper respiratory tract symptoms were the most frequent reasons for which respondents indicated they would self-medicate. 48.4% of the whole group replied that they kept antibiotics at home, being highest in Lebanon (60%, 95% CI 51%, 69%). We found a significant association between antibiotic hoarders and intended users of antibiotics for self-medication. Our data confirms that non-prescribed antibiotic use is high within ambulatory care in southern and eastern Mediterranean countries, being almost twice that reported in a similar European study. Corrective efforts are clearly required in the region to ensure proper use of antimicrobials so as to reduce pressure for antimicrobial resistance.

Contrast effects in spontaneous evaluations: A psychophysical account.

In the affective-priming paradigm, target stimuli are preceded by evaluatively polarized prime stimuli and then are to be classified as either good or bad as fast as possible. The typical and robust finding is assimilation: Primes facilitate the processing of evaluatively consistent targets relative to evaluatively inconsistent targets. Nevertheless, contrast effects have repeatedly been observed. The authors propose a new psychophysical account of normal (assimilative) and reversed (contrastive) priming effects and test new predictions derived from it in 5 studies: In Studies 1 and 2, the authors' account is shown to provide a better explanation of contrastive effects in a priming paradigm with two primes than the traditional attentional account does. Furthermore, as predicted by the new account, contrast effects emerge at an intermediate stimulus-onset asynchrony (SOA, Study 3) and even with short SOAs when target onset takes participants by surprise (Study 4). Finally, the use of extremely valenced primes triggers corrective efforts (Study 5) as predicted. Implications for priming measures of evaluative associations are discussed.

A dynamic model of the Bay of Biscay pelagic fleet simulating fishing trip choice: the response to the closure of the European anchovy (Engraulis encrasicolus) fishery in 2005

The scope of this paper is to describe, evaluate, and forecast fishing trip choices of the Bay of Biscay pelagic fleet using random utility modeling (RUM). First, alternative fishing trip choices of this fleet were identified using multivariate statistical methods based on species landings weighted by value and defined as distinct fishing activity or fisheries (termed métiers). A RUM was specified, which included trip components as attributes during the period 2001–2004 (a lagged percentage of the value per unit of effort of the main species caught, total value per unit of effort, and inertia in terms of changes from one métier to another). For the main métiers, the proportion of correct effort allocation is 90% during the calibration period of 2001–2004. The results from the RUM are used to parameterize a simulation model of trip choice. The model is used to predict trip choices in 2005, throughout most of which fishing was constrained by the closure of the European anchovy (Engraulis encrasicolus) fishery. Simulation results are compared with observed trip choices following the fishing ban: 80% of observed trip choices are correctly predicted by the model. The capacity of the behavioral model to predict responses to the closure is then discussed.

Analyzing Factors of Defect Correction Effort in a Multi-Vendor Information System Development

This paper describes an empirical study to reveal factors influencing defect correction effort in software development. In the study we collected various attributes (metrics) of defects found in a typical medium-scale, multi-vendor information system development project in Japan over a six-month period. We then statistically analyzed the relationship between the defects' attributes and the correction effort. The analysis confirmed the well-known principle “defects are the more expensive the later they are detected” by revealing that defects detected in the “system test” were 4.88 times more expensive than those detected in the “coding/unit test”. Another principle “defects are more expensive the longer they survive in software” was also confirmed by revealing that defects, which survived two or more development phases, were 4.44 times more expensive than those detected immediately. We also identified other factors, such as defect reproducibility, severity, and the cause of detection delay, that had a significant influence on the correction effort.

An Assessment of the Biases of Satellite Rainfall Estimates over the Tibetan Plateau and Correction Methods Based on Topographic Analysis

AbstractThe hydrological processes over the Tibetan Plateau have significant implications on regional macroscale atmospheric circulation patterns and the Asian monsoon system. Because of its remote setting and lack of ground observations, it is difficult to study the spatial and temporal patterns of precipitation over the plateau, and satellite remote sensing technology can be used to fill in the gaps where station data are not available. In this study the authors examine monthly 1° × 1° rainfall estimates obtained from the Special Sensor Microwave Imager (SSM/I) [National Environmental Satellite, Data, and Information Service (NESDIS) algorithm] and Tropical Rainfall Measuring Mission (TRMM) 3B42 version 5 (V5) products for the months of April–October 1998–2002 over the Tibetan Plateau. By comparing the satellite estimates with ground observations at 94 weather stations in the study region, the authors derived regression models that produced significant improvements to satellite estimates based on various levels of correction efforts, using geographic location and topographic variables extracted from digital elevation models using geographic information systems (GIS) technology. The explained variance in observed precipitation was improved from 34% to 38% by SSM/I and TRMM 3B42 V5 products alone to over 70% when location and topographic variables were added. These topographic variables reflect micro- to mesoscale surface roughness, height of topographic features or relief, slopes facing toward or away from the moisture pathways, and relative locations or directions to prominent topographic features such as mountain peaks and ridgelines.

From the deal world to the real world: maximizing M&amp;A value after the deal is done

PurposeThe purpose of this paper is to provide the key dos and don'ts when integrating the people, processes, and systems of companies undertaking mergers and/or acquisitions.Design/methodology/approachThe paper provides the current state of M&amp;A integration across industries, integration dynamics and common pitfalls, integration best practices, and a section regarding how to conduct “merger repair” activities in order to correct integration efforts that have gotten off track.FindingsThe measurable impacts of well‐conducted M&amp;A integration efforts is presented and discussed.Practical implicationsKey implications for management who are pursuing a merger and/or acquisition strategy are demonstrated throughout the key success factors described in this paper.Originality/valueThe value to the reader is found in the practical recommendations and tangible actions identified. Likewise, the section describing the need for and how to conduct “merger repair” is new to the literature pertaining to M&amp;A integration.

An integrated fuzzy-stochastic modeling approach for assessing health-impact risk from air pollution

High concentrations of air pollutants in the ambient environment can result in breathing problems with human communities. Effective assessment of health-impact risk from air pollution is important for supporting decisions of the related detection, prevention, and correction efforts. However, the quality of information available for environmental/health risk assessment is often not satisfactory enough to be presented as deterministic numbers. Stochastic method is one of the methods for tackling those uncertainties, by which uncertain information can be presented as probability distributions. However, if the uncertainties can not be presented as probabilities, they can then be handled through fuzzy membership functions. In this study, an integrated fuzzy-stochastic modeling (IFSM) approach is developed for assessing air pollution impacts towards asthma susceptibility. This development is based on Monte Carlo simulation for the fate of SO2 in the ambient environment, examination of SO2 concentrations based on the simulation results, quantification of evaluation criteria using fuzzy membership functions, and risk assessment based on the combined fuzzy-stochastic information. The IFSM entails (a) simulation for the fate of pollutants in ambient environment, with the consideration of source/medium uncertainties, (b) formulation of fuzzy air quality management criteria under uncertain human-exposure pathways, exposure dynamics, and SPG-response variations, and (c) integrated risk assessment under complexities of the combined fuzzy/stochastic inputs of contamination level and health effect (i.e., asthma susceptibility). The developed IFSM is applied to a study of regional air quality management. Reasonable results have been generated, which are useful for evaluating health risks from air pollution. They also provide support for regional environmental management and urban planning.

3.2.2 Enabling Economics‐Driven Systems Engineering Through Reusable Software Architectures and Components

AbstractEconomics‐driven systems engineering integrates system design principles with measurement‐based analyses of value, options, and tradeoffs. This study helps enable economics‐driven systems engineering by describing an example of measurement‐based analysis of software reuse in large‐scale systems. Software reuse enables developers to leverage past accomplishments and facilitates significant improvements in software productivity and quality. Software reuse catalyzes gains in productivity by avoiding redevelopment and gains in quality by incorporating components whose reliability has already been established. The purpose of this study is to characterize software reuse empirically by investigating one development environment that actively reuses software. Twenty‐five software systems ranging from 3000 to 112,000 source lines have been selected for analysis from a NASA systems development environment. The amount of software either reused or modified from previous systems averages 32% per project in this environment. Non‐parametric statistical models are applied to examine numerous development variables across the software modules in the systems. This research focuses on initial results and graphical characterizations of the data. Four classes of software modules are analyzed: (a) modules reused without revision, (b) modules reused with slight revision (&lt; 25% changes), (c) modules reused with major revision (≥ 25% changes), and (d) newly developed modules. The modules reused without revision had the fewest faults, lowest fault correction effort, and lowest fault densities. In conclusion, we outline future research directions that build on these strategies and ideas.