Confidence In Correctness Research Articles

Rustlantis: Randomized Differential Testing of the Rust Compiler

Compilers are at the core of all computer architecture. Their middle-end and back-end are full of subtle code that is easy to get wrong. At the same time, the consequences of compiler bugs can be severe. Therefore, it is important that we develop techniques to increase our confidence in compiler correctness, and to help find the bugs that inevitably happen. One promising such technique that has successfully found many compiler bugs in the past is randomized differential testing , a fuzzing approach whereby the same program is executed with different compilers or different compiler settings to detect any unexpected differences in behavior. We present Rustlantis , the first fuzzer for the Rust programming language that is able to find new correctness bugs in the official Rust compiler. To avoid having to deal with Rust’s strict type and borrow checker, Rustlantis directly generates MIR, the central IR of the Rust compiler for optimizations. The program generation strategy of Rustlantis is a combination of statically tracking the state of the program, obscuring the program state for the compiler, and decoy blocks to lead optimizations astray. This has allowed us to identify 22 previously unknown bugs in the Rust compiler, most of which have been fixed.

Undoubtedly unaware of homonymous hemianopia: The contribution of overconfidence to anosognosia of hemianopia

A new functional deficit caused by a stroke can be understood as a situation of uncertainty that has to prompt deficit discovery and subsequent incorporation into an altered self-perception. Anosognosia for visual field deficits is frequent after stroke. For hemiplegia, patients' performance in a riddle test provided evidence that the inability to generate and adjust beliefs in face of uncertainty contributes to anosognosia for hemiplegia. In this prospective study, the same riddles are used in patients with homonymous hemianopia due to a first-ever stroke in the posterior cerebral artery territory and in an age-matched control cohort. The riddles create a situation of uncertainty that is resolved with five successive clues which progressively delimit the target word. After each clue, patients have to guess the target word and rate their confidence in the answer's correctness. Patients were tested once during the hospital stay. According to the Bisiach score for anosognosia, 12 out of 29 patients were unaware of their visual field deficits. All patients with anosognosia for hemianopia had right hemisphere lesions. Patients with and without anosognosia did not differ significantly in global cognitive impairment, mental flexibility or memory function. Importantly, patients with anosognosia showed higher confidence ratings than patients without anosognosia and controls in the first two clues (situations of uncertainty). This was demonstrated by a significant interaction effect in a mixed ANOVA with the factors group (anosognosia, nosognosia, controls) and riddle clues. An exploratory lesion subtraction analysis showed a high proportion of deficit unawareness in patients with lesions in the right fusiform and (para)hippocampal gyri. Our findings suggest that overconfidence in situations of uncertainty might contribute to the appearance of anosognosia for hemianopia. Because this has been demonstrated before in anosognosia for hemiplegia, we suggest that overconfidence is a supra-modal contributor to deficit unawareness.

Языковые средства выражения категоричности в современной англоязычной научной прозе

The aim of the paper is to identify the linguistic means of utterance categoricity in modern English-language scientific texts on linguistics. The paper analyzed examples from modern English-language scientific monographs and collections of articles that use categorical utterance techniques, identified the multi-level ways of creating categoricity in a scientific text and assessed their effectiveness in such texts. The study is novel in that it is the first to highlight the techniques and methods of categoricity expression in English-language scientific prose, as well as to summarize the means for achieving maximum impact on the addressee. The results of the study showed that utterance categoricity in an English-language scientific text is of a communicative nature and is determined mainly by the degree of the author’s confidence in the absolute correctness of his/her statements. The categoricity effect in scientific texts can mainly be achieved through the redundancy of information technique, by combining deontic constructions and modal intensifier constructions, the emphatic ‘do’, intensive words and syntactic constructions with the adversative or concessive meaning and the emphatic split construction ‘It is… that’.

A Neural Model to Jointly Predict and Explain Truthfulness of Statements

Automated fact-checking (AFC) systems exist to combat disinformation, however, their complexity usually makes them opaque to the end-user, making it difficult to foster trust in the system. In this article, we introduce the E-BART model with the hope of making progress on this front. E-BART is able to provide a veracity prediction for a claim and jointly generate a human-readable explanation for this decision. We show that E-BART is competitive with the state-of-the-art on the e-FEVER and e-SNLI tasks. In addition, we validate the joint-prediction architecture by showing (1) that generating explanations does not significantly impede the model from performing well in its main task of veracity prediction, and (2) that predicted veracity and explanations are more internally coherent when generated jointly than separately. We also calibrate the E-BART model, allowing the output of the final model to be correctly interpreted as the confidence of correctness. Finally, we also conduct an extensive human evaluation on the impact of generated explanations and observe that: Explanations increase human ability to spot misinformation and make people more skeptical about claims, and explanations generated by E-BART are competitive with ground truth explanations.

Modeling and Verification of Aircraft Takeoff Through Novel Quantum Nets

The formal modeling and verification of aircraft takeoff is a challenge because it is a complex safety-critical operation. The task of aircraft takeoff is distributed amongst various computer-based controllers, however, with the growing malicious threats a secure communication between aircraft and controllers becomes highly important. This research serves as a starting point for integration of BB84 quantum protocol with petri nets for secure modeling and verification of takeoff procedure. The integrated model combines the BB84 quantum cryptographic protocol with powerful verification tool support offered by petri nets. To model certain important properties of BB84, a new variant of petri nets coined as Quantum Nets are proposed by defining their mathematical foundations and overall system dynamics, furthermore, some important system properties are also abstractly defined. The proposed Quantum Nets are then applied for modeling of aircraft takeoff process by defining three quantum nets: namely aircraft, runway controller and gate controller. For authentication between quantum nets, the use of external places and transitions is demonstrated to describe the encryption-decryption process of qubits stream. Finally, the developed takeoff quantum network is verified through simulation offered by colored petri-net (CPN) Tools. Moreover, reachability tree (RT) analysis is also performed to have greater confidence in feasibility and correctness of the proposed aircraft takeoff model through the Quantum Nets.

Theory of Interpretation of Law in Modern German legal Doctrine

Currently, in the legal doctrine of Germany, a heated discussion continues between representatives of the objective and subjective schools of interpretation. Opponents of the objective theory argue that the mistakenly called «objective» method, which largely supplants the will of the legislator, leads to the fact that from a rule of law based on the principle of separation of powers, Germany turns into a «state of judges». The purpose of this work is to study the content and topical problems of objective and subjective theories of interpretation of law in the modern German legal doctrine. To achieve this goal, the following tasks are being solved: the analysis of the content and structure of theories of interpretation in the modern legal doctrine of Germany is carried out; defines the distinction between the concepts of interpretation (Auslegung) and development (Rechtsfortbildung) of law; analyzes the position of the Federal Constitutional Court of the Federal Republic of Germany on the choice of the method of interpretation; the position of German legal scholars on the admissibility of «judicial law» is analyzed. In the course of the study, the following methods were used: analysis and synthesis, hermeneutic, comparative method. As a result of the study, it was possible to come to the following conclusions: 1) in contrasting the subjective and objective theories of the interpretation of normative legal acts in the modern German legal doctrine, the complex difference between the interpretation (Auslegung) and the development of law (Rechtsfortbildung) is considered, for the substantiation of which changing semantic theories are used, which are based not only on a methodological problem, but also, possibly, a different understanding of the Constitution and ideas about the tasks, as well as the boundaries of jurisprudence. Subjective theory attaches decisive importance to the regulative will of the legislator, the correct method of interpretation according to this theory is to first investigate the historical prescription and purpose (Zweck). The objective theory, on the contrary, proceeds from the idea that the law from the moment of publication «breaks away» from the legislator and henceforth is independent, so that the will of the rulemaker no longer matters; 2) the need for a clear delimitation of the judicial development of law from interpretation. The limitation of judicial possibilities in the interpretation and development of law lies in the fact that they must be carried out according to the accepted rules of interpretation. The established methodology, that is, the formal correctness of the trial, provides, to a certain extent, confidence in the material correctness of the decision and prevents arbitrariness.

Application of METAP methodology for clinical ethics consultation in end-of-life care in Bulgaria

Although clinical ethics consultation has existed for more than 40 years in the USA and Europe, it was not available in Bulgaria until recently. In introducing clinical ethics consultation into our country, the Modular, Ethical, Treatment, Allocation of resources, Process (METAP) methodology has been preferred because of its potential to be used in resource-poor settings and its strong educational function. This paper presents the results of a METAP evaluation in a hospital palliative care ward in the town of Vratsa. The evaluation was based on Beauchamp and Childress’ four principles of biomedical ethics and involves implementation of specific instruments for clinical ethics decision-making. Research tasks emphasised analyses of ethics meetings in the ward. Data were processed by SPSS v.24 using descriptive statistical analysis. Altogether, 32 ethics meetings of an average duration 20.63 min were conducted on cases involving critically ill patients. Most of the participants (86.0%) expressed satisfaction with the ethics process. The principlist approach supported resolution of conflicts between autonomous patients and their relatives, clarified definitions of “medical benefit” and “social good,” and enabled assessments of the risk of unequal treatment. Even as the specific research tasks were achieved, further participant follow-up is necessary to identify any improvement in healthcare personnel’s ethical competence. METAP worked well in end-of-life care settings. Participants experienced several benefits, including improved team communication, better understanding of patient preferences, and confidence in the correctness of decisions. Despite the significant educational potential of METAP, the need for additional and ongoing ethics training of health professionals should not be underestimated.

Swarm Intelligence Techniques and Genetic Algorithms for Test Case Prioritization

Regression testing is a technique which is carried out to ascertain that the changes that were done in the source code have not negatively damped its performance. Hence, it is a crucial and an expensive step of the software development life cycle. It re-establishes confidence in correctness of the software after changes were made to it. A test suite is used to test the software, but often it becomes time consuming to re-execute each test case every time regression testing is done. Therefore, it becomes essential to decrease the number of the test cases by prioritizing them based on some criterion. This ensures maximum detection of faults in least amount of time. In this paper, author has compared swarm intelligence techniques with genetic algorithms for such a test suite prioritization. In particular, by taking a sample GCD program Ant Colony Optimization (ACO) has been compared with Genetic Algorithms (GA) for the purpose of test suite minimization. Unit of comparison has been execution time required for prioritization of test cases. Further, experimental results have been compared with time taken by both with random testing.

Motivativational Readiness of Future Officers of Missiles and Artillery Armament as a Factor of Their Professional Development

The article is devoted to the motivational readiness of future officers of missiles and artillery armament as a factor of their professional development. The author noted that the motives occupy an increasingly prominent place in the structure of future missile and artillery armament officers’ professional training for a future military service. These motives are determined in the article as a person’s inner encouragement to activity, connected with meeting certain needs. The benefit of this study is that a group of motives that determine the professional activity of military specialists has been identified. Moreover, the analysis of the motivational sphere gave grounds to identify the needs of the cadets: an attractiveness of the specialty, a physical training, a military honor and dignity, relations with colleagues, obtaining a civilian specialty for budgetary funds, a social status, and an extension of family traditions of military service. The motivational readiness of cadets is characterized by the appropriate orientation and the presence of the content of activities, the professional attitudes of an individual. As a result, the cadets’ motivational readiness is defined as a stable system of the person’s psychological formations that create appropriate states of mind and encourage military experts to work. The author has made a conclusion in the article that the professional training of a future officer of missile and artillery armament should result in the following: the qualitative performance of operational duties; the ability to make interpersonal relations with a personnel; the ability to see the point in a military service, to set goals, and to exert an insistence in reaching them, to rationally share the duties among the military servicemen, to get a job done; the ability to adapt for a change in social environment through general and military education; a desire for continuous self- development; a confidence in personal skills and correctness of the path pursued. The following three levels of motivational readiness of future officers are revealed by the author of the article: high level (characterized by a pronounced need in military professional self- development), average level (distinguished by the motivational and value structure), low level (characterized by a poor value orientation and military service guidance).

Retrofitting the BCTRAN Transformer Model With Nonlinear Magnetizing Branches for the Accurate Study of Low-Frequency Deep Saturating Transients

In this paper, an extension to the multiwinding BCTRAN model is proposed for the study of low-frequency saturating transients in single-phase transformers. The conventional experimentally obtained BCTRAN (winding leakage) susceptance matrix is retrofitted with a previously missing experimentally obtained nonlinear (core magnetizing) model. The assembled model gives accurate results for transients in all terminals. The model parameters can be acquired from information available in the nameplate plus terminal tests without the need of detailed transformer design or construction information. Only needed are standard no-load and impedance tests plus a newly introduced saturation test. Very simple formulas are proposed to compute the parameters. Illustrative examples on how the parameters are computed are given for three transformers rated 1.8, 5, and 75 kVA. For model validation, laboratory inrush currents tests are carried out and compared with simulations using the EMTP-RV. The results show that the simulations and experimental results match very closely giving great confidence in the model correctness and parameter estimation method.

SafeGPU: Contract- and library-based GPGPU for object-oriented languages

Using GPUs as general-purpose processors has revolutionized parallel computing by providing, for a large and growing set of algorithms, massive data-parallelization on desktop machines. An obstacle to their widespread adoption, however, is the difficulty of programming them and the low-level control of the hardware required to achieve good performance. This paper proposes a programming approach, SafeGPU, that aims to make GPU data-parallel operations accessible through high-level libraries for object-oriented languages, while maintaining the performance benefits of lower-level code. The approach provides data-parallel operations for collections that can be chained and combined to express compound computations, with data synchronization and device management all handled automatically. It also integrates the design-by-contract methodology, which increases confidence in functional program correctness by embedding executable specifications into the program text. We present a prototype of SafeGPU for Eiffel, and show that it leads to modular and concise code that is accessible for GPGPU non-experts, while still providing performance comparable with that of hand-written CUDA code. We also describe our first steps towards porting it to C#, highlighting some challenges, solutions, and insights for implementing the approach in different managed languages. Finally, we show that runtime contract-checking becomes feasible in SafeGPU, as the contracts can be executed on the GPU.

State of the practice for mesh generation and mesh processing software

We analyze the state of development practices for Mesh Generation and Mesh Processing (MGMP) software by comparing 27 MGMP projects. The analysis employs a reproducible method based on a grading template of 56 questions covering 13 software qualities. The software is ranked using the Analytic Hierarchy Process (AHP), a multicriteria decision making method appropriate for cases with a mix of qualitative and quantitative factors. The results reveal concerns regarding the maintainability, usability, reusability and performance of some MGMP software. Five recommendations are presented as feedback to the MGMP community: (i) Use an issue tracker for bug management and support requests. (ii) Document performance measures. (iii) Increase the use of libraries to promote software re-use to avoid “re-inventing the wheel.” (iv) Improve reproducibility by recording the set up details for the development and testing environments. (v) Improve confidence in correctness through requirements specification, formal specification languages, and automated testing.

The verification of a distributed system

A practitioner's guide to increasing confidence in system correctness.

Contract-based general-purpose GPU programming

Using GPUs as general-purpose processors has revolutionized parallel computing by offering, for a large and growing set of algorithms, massive data-parallelization on desktop machines. An obstacle to widespread adoption, however, is the difficulty of programming them and the low-level control of the hardware required to achieve good performance. This paper suggests a programming library, SafeGPU, that aims at striking a balance between programmer productivity and performance, by making GPU data-parallel operations accessible from within a classical object-oriented programming language. The solution is integrated with the design-by-contract approach, which increases confidence in functional program correctness by embedding executable program specifications into the program text. We show that our library leads to modular and maintainable code that is accessible to GPGPU non-experts, while providing performance that is comparable with hand-written CUDA code. Furthermore, runtime contract checking turns out to be feasible, as the contracts can be executed on the GPU.

Comparing Psychology Undergraduates Performance in Probabilistic Reasoning Under Verbal-Numerical and Graphical-Pictorial Problem Presentation Format: What is the Role of Individual and Contextual Dimensions?

This study aims to investigate about the existence of a graphical facilitation effect on probabilistic reasoning. Measures of undergraduates’ performances on problems presented in both verbal-numerical and graphical-pictorial formats have been related to visuo-spatial and numerical prerequisites, to statistical anxiety, to attitudes towards statistics and to the confidence in response correctness. Psychology undergraduates in Italy and Spain with no statistical expertise (N= 676) completed a protocol under conditions of presence versus absence of time pressure. Hierarchical linear regressions and ANCOVAs with mixed design have been carried out separately for each sample. The best predictor of performance in both formats has been the confidence in solution correctness under the condition of time pressure administration, which seemed to promote the commitment to the task. The findings suggest that the eventual occurrence of a graphical facilitation could be the result of a multifactorial interaction among contextual and individual dimensions, rather than being strictly related to the problem presentation format.

Refutations in science texts lead to hypercorrection of misconceptions held with high confidence

Misconceptions about science are often not corrected during study when they are held with high confidence. However, when corrective feedback co-activates a misconception together with the correct conception, this feedback may surprise the learner and draw attention, especially when the misconceptions are held with high confidence. Therefore, high-confidence misconceptions might be more likely to be corrected than low-confidence misconceptions. The present study investigates whether this hypercorrection effect occurs when students read science texts. Effects of two text formats were compared: Standard texts that presented factual information, and refutation texts that explicitly addressed misconceptions and refuted them before presenting factual information. Eighth grade adolescents (N = 114) took a pre-reading test that included 16 common misconceptions about science concepts, rated their confidence in correctness of their response to the pre-reading questions, read 16 texts about the science concepts, and finally took a post-test which included both true/false and open-ended test questions. Analyses of post-test responses show that reading refutation texts causes hypercorrection: Learners more often corrected high-confidence misconceptions after reading refutation texts than after reading standard texts, whereas low-confidence misconceptions did not benefit from reading refutation texts. These outcomes suggest that people are more surprised when they find out a confidently held misconception is incorrect, which may encourage them to pay more attention to the feedback and the refutation. Moreover, correction of high-confidence misconceptions was more apparent on the true/false test responses than on the open-ended test, suggesting that additional interventions may be needed to improve learners' accommodation of the correct information.

DEVELOPMENT AND VALIDATION OF AN IMPROVED TEST SELECTION AND PRIORITIZATION ALGORITHM BASED ON ACO

Regression testing is an important and often costly software maintenance activity. Retesting the software using existing test suite whenever modifications are made to the system, in order to regain confidence in correctness of the system, is called as Regression Testing. Regression test suites are often too large to re-execute in the given time and cost constraints. Reordering of the test suite is done according to appropriate criteria like code, branch, condition and fault coverage, etc. This process is known as Test Suite Prioritization. We can also select a subset of the original test suite on the basis of some criteria, often called as Regression Test Selection. The research problem that arises from this is the choice of technique or process to be used for selecting and prioritizing according to one or more of the chosen criteria(s). Ant Colony Optimization (ACO) is one such technique that was used by Singh et al. for solving Time-Constrained Test Suite Selection and Prioritization problem using Fault Exposing Potential (FEP). In this paper, we propose improvements to the existing algorithm along with details of the time complexity of the algorithm. It was very convincing to implement the technique considering the results obtained. Implementation of the proposed algorithm has also been demonstrated. The tool was repeatedly run on sample programs by changing the time constraint criterion. The analysis shows the usefulness and effectiveness of using ACO technique for test suite selection and prioritization.

Advanced Saturation-based Model Checking of Well-formed Coloured Petri Nets

The failure of safety-critical embedded systems may have catastrophic consequences, therefore their development process requires a strong verification procedure to obtain a high confidence of correctness in the specification and implementation. Formal modelling and model checking provides a rigorous, mathematically precise verification method. Practical embedded systems are typically complex, distributed and asynchronous, thus they need expressive and compact formal models, and efficient model checking approaches. The saturation algorithm has an efficient iteration strategy. Combined with symbolic data structures, it can be used for state space generation and model checking of asynchronous systems. Coloured Petri nets are a good choice for modelling distributed and asynchronous systems, however their integration with saturation has not been solved in the past. In this paper we describe a new approach for applying saturation-based state space generation and model checking to coloured Petri nets. We demonstrate the performance of our new algorithm on the verification of a safety function used in the Reactor Protection System of a nuclear power plant.

Test-first design pedagogy in introductory Java programming

Java is used in many introductory CS courses (including the AP CS course). This tutorial introduces the Java tester library that supports the test-first design pedagogy in Java from the beginning. Test-first design forces students to reason about the planned methods, to think about their behavior and the expected outcomes before designing the method bodies. Professional programmers have commented on the positive aspects of this approach: smaller methods, decreased stress, better code, higher confidence in the code correctness.

Russian Industry in March 2013

The business opinion surveys carried out by the Gaidar Institute in March 2013 pointed to a worsening situation for Russian industrial enterprises. As a result, industrial enterprises began to lose confidence in the correctness of their production and marketing policies, and so were trying to push their output to match demand more closely. Their sales forecasts and output plans gave no reasons to expect that Russian industry might experience a rebound in growth – even if enterprises refrained from rising prices for their products.