Human Error Analysis in Software Engineering

As the primary cause of software defects, human error is the key to understanding, detecting and preventing software defects. This chapter first reviews the state of art of an emerging area: software fault defense based on human error mechanisms. Then, an approach for human error analysis (HEA) is proposed. HEA consists of two important components: human error modes (HEM) and an undated version of causal mechanism graphs (CMGs). Human error modes are the general erroneous patterns that humans tend to behave in a variety of activities. Causal mechanism graph provides a way to extract the error-prone contexts in software development, and link the contexts to general human error modes. HEA can be used at various phases of software development, for both defect detection and prevention purposes. An application case is provided to demonstrate how to use HEA

3,4-Dicyano­phenyl 2,3,4,6-tetra-O-acetyl-α-d-glucopyran­oside

The title compound, C22H22N2O10, was prepared by the glycosidation method through nitrite displacement on substituted nitro­phthalonitrile. The mol­ecule contains a benzene ring, two nitrile groups and an acetyl-protected d-glucose fragment which adopts a chair conformation. The absolute configuration was determined by the use of d-glucose as starting material. All substituents of the protected sugar are in equatorial positions, with the exclusive presence of the α-anomer. The crystal packing is stabilized by C—H⋯O and C—H⋯N hydrogen-bonding inter­actions

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

The original version of this article unfortunately contained a mistake

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Software Defect Defense based on Human Error Mechanisms

Documentos apresentados no âmbito do reconhecimento de graus e diplomas estrangeirosSoftware defects are the critical threat to increase life-cycle costs, delay project schedule, reduce the reliability of software systems, and even cause catastrophic disasters. Since the concept of software engineering has been proposed, people have developed many technologies to prevent the introduction of software defects. However, the effects are not optimistic. So far although tremendous resources have been devoted to software testing, defects are still the major threat to the reliability of software systems. The proactive defense against software defects can be a promising philosophy to reduce costs and improve reliability. However, conventional relevant technologies such as defect prediction and defect prevention can hardly prevent the introduction of software defects. It is the time to prompt a thorough reflection on the conventional ways: the conventional technologies trend to focus on the improvement of software process, but ignore the underlying mechanisms that cause software defects. Essentially, programs are the “expression” of human thoughts, while software defects are mainly caused by human cognitive failures. Conventional software engineering technologies are designed to control and improve the process of software production, rather than directly impact on the key factor---programmer’s cognition, thus, they can only influence software quality indirectly. Once we have failed to capture the mechanisms of software defects, we can neither predict them precisely, nor prevent them fundamentally. To address these gaps, this thesis proposes the concept of defect defense based on human error mechanisms. Logically, prediction and prevention should be interconnected, since only when an event can be predicted, it can be prevented. That is to say, prediction normally provides implications for prevention. However, due to the omission of mechanisms, the conventional defect prediction is unable to achieve sufficient accuracy at early stages of software development. Thus, conventional predictions can provide little information for defect prevention. That’s why the conventional defect prediction and prevention are completely irrelevant. In this thesis, bonded by the human error mechanisms, prediction and prevention are integrated, to defend against the introduction of software defects together. The research is first carried out by summarizing the relevant research about program design cognition, with an integrated cognition model of program design constructed. Then integrate the classical theories of human errors with the domain characteristics of programming, a base of human error modes for software defects is developed. Based on the integrated cognition model and human error modes, three approaches are proposed, designed and validated. “Conventional defect prevention (DP) based on the structural taxonomy of root causes” is an improved defect prevention approach in the framework of conventional DP. Conventional DP framework is effective in preventing defects due to process problems. However, it is strongly depended on experts’ experiences and brain storms, which have limit its applications in small companies. Even for companies at high process maturity levels, it is hard to replicate the benefits of conventional DP. A structural taxonomy of root causes is proposed and validated, and the core knowledge required for root cause analysis is solidified in the knowledge base. An application case has been carried out, results show that with the assistance of the taxonomy and knowledge base, the small company at the CMM initial level can implement conventional DP effectively. “Defect Prevention by Improving Software Developers’ Meta-cognitive Ability to Prevent Human Errors” (HEDP) is an approach in the framework that is completely different from conventional DP. This approach is proposed for the reason that, individual cognitive failures are the main cause of software defects, but conventional DP has little power in affecting individual’s cognitive performances. HEDP aims to prevent defects by improving programmers’ awareness and regulation abilities under error-prone situations. HEDP is designed in the framework of meta-cognition, including two stages. The first stage concerns meta-cognitive training on human error knowledge and the second stage aims to build programmers’ experience in meta-cognitive regulation. The knowledge training consists of knowledge about program designing cognition, human error mechanisms, and error prevention strategies. The meta-cognitive regulation experience is built by the reflection in the course of problem solving and self-reviews after the defects are detected. Two application cases are studied, with the self-assessment and defect data collected. Both kinds of results show that, HEDP is effective in improving programmers’ meta-cognitive ability to prevent software defects. Furthermore, HEDP is independent of process maturity, that is to say, all organizations can implement HEDP, no matter at CMM level 5 or level 1. Most important of all, HEDP can be used to guide any programmer pursuing self-improvement in human error prevention, no matter experts or novices. “Software defect prediction based on human error mechanisms”(HEFP) is an new approach to predict the location and format of defects at the early phases of software development, i.e. phases of requirement analysis and design. Such prediction is implemented by human error scenario analysis. A controlled experiment has been designed to validate HEFP and provides empirical evidences for relevant concepts. The results show that, HEFP has predominant advantages in predicting coincident defects. HEFP has precisely predicted the location and format of 88.9% coincident defects, which are committed by 96.5% of the subjects who has committed coincident defects. Meanwhile, what the HEFP predicts are the defects at high risk. Though the number of defects predicted by HEFP only constitutes 30.8% of the total defects, but they are committed by 78.6% subjects who commit any error. In comparison, conventional predictors based on program metrics can only account for 26.8% variance of the total defects, and they can not output the accurate locations and formats of the defects. Results show that HEFP performs much better than prediction models based on program metrics, both in the accuracy and efficiency. Most important of all, HEFP can perform at the early phases of the software development, thus it can provide implications for defect prevention. In summary, the two sets of basic theories and three approaches works together, constituting the comprehensive system to defend against software defects

Identity-Based Identification Scheme without Trusted Party against Concurrent Attacks

Identification schemes support that a prover who holding a secret key to prove itself to any verifier who holding the corresponding public key. In traditional identity-based identification schemes, there is a key generation center to generate all users’ secret keys. This means that the key generation center knows all users’ secret key, which brings the key escrow problem. To resolve this problem, in this work, we define the model of identity-based identification without a trusted party. Then, we propose a multi-authority identity-based identification scheme based on bilinear pairing. Furthermore, we prove the security of the proposed scheme in the random oracle model against impersonation under passive and concurrent attacks. Finally, we give an application of the proposed identity-based identification scheme to blockchain

Spacious Environments Make Us Tolerant—The Role of Emotion and Metaphor

The physical environment plays an important role in moral cognition. Previous research has demonstrated that the physical environment affects individual moral judgment. Investigators have argued that the environment influences moral judgment through emotion and cognition, such as during metaphor processing. Following the intensification of urbanization and increases in population size, the phenomenon of a narrow environment has become more common. However, the relation between environmental spaciousness and moral judgment has not been thoroughly examined. We examined the effect of environmental spaciousness (spaciousness vs. narrowness) on moral judgments in Experiment 1 and Experiment 2. Results showed that participants report a higher rating score of moral judgment in more spacious environments compared with narrow environments. We further explored the roles of emotion and metaphor in the relation between environmental spaciousness and moral judgments. We found support for a partial mediation effect of emotion in the relationship between environmental spaciousness and moral judgment. The results also supported an association between the concept of spaciousness and tolerant cognition. Spacious environments may elicit positive emotions and more tolerant cognition, which in turn influences moral judgment. These results provide new evidence for the influence of the environment on moral judgments, and more attention may be warranted to incorporate this relationship in environmental design

Analysis of tanshinone IIA induced cellular apoptosis in leukemia cells by genome-wide expression profiling

<p>Abstract</p> <p>Background</p> <p>Tanshinone IIA (Tan IIA) is a diterpene quinone extracted from the root of <it>Salvia miltiorrhiza</it>, a Chinese traditional herb. Although previous studies have reported the anti-tumor effects of Tan IIA on various human cancer cells, the underlying mechanisms are not clear. The current study was undertaken to investigate the molecular mechanisms of Tan IIA's apoptotic effects on leukemia cells in vitro.</p> <p>Methods</p> <p>The cytotoxicity of Tan IIA on different types of leukemia cell lines was evaluated by the 3-[4,5-dimethylthiazol-2,5]-diphenyl tetrazolium bromide (MTT) assay on cells treated without or with Tan IIA at different concentrations for different time periods. Cellular apoptosis progression with and without Tan IIA treatment was analyzed by Annexin V and Caspase 3 assays. Gene expression profiling was used to identify the genes regulated after Tan IIA treatment and those differentially expressed among the five cell lines. Confirmation of these expression regulations was carried out using real-time quantitative PCR and ELISA. The antagonizing effect of a PXR inhibitor L-SFN on Tan IIA treatment was tested using Colony Forming Unit Assay.</p> <p>Results</p> <p>Our results revealed that Tan IIA had different cytotoxic activities on five types of leukemia cells, with the highest toxicity on U-937 cells. Tan IIA inhibited the growth of U-937 cells in a time- and dose-dependent manner. Annexin V and Caspase-3 assays showed that Tan IIA induced apoptosis in U-937 cells. Using gene expression profiling, 366 genes were found to be significantly regulated after Tan IIA treatment and differentially expressed among the five cell lines. Among these genes, CCL2 was highly expressed in untreated U-937 cells and down-regulated significantly after Tan IIA treatment in a dose-dependent manner. RT-qPCR analyses validated the expression regulation of 80% of genes. Addition of L- sulforaphane (L-SFN), an inhibitor of Pregnane × receptor (PXR) significantly attenuated Tan IIA's effects using colony forming assays.</p> <p>Conclusions</p> <p>Tan IIA has significant growth inhibition effects on U-937 cells through the induction of apoptosis. And Tan IIA-induced apoptosis might result from the activation of PXR, which suppresses the activity of NF-κB and lead to the down-regulation of CCL2 expression.</p