Putting Them under Microscope: A Fine-Grained Approach for Detecting Redundant Test Cases in Natural Language

Natural language (NL) documentation is the bridge between software managers and testers, and NL test cases are prevalent in system-level testing and other quality assurance activities. Due to reasons such as requirements redundancy, parallel testing, and tester turnover within long evolving history, there are inevitably lots of redundant test cases, which significantly increase the cost. Previous redundancy detection approaches typically treat the textual descriptions as a whole to compare their similarity and suffer from low precision. Our observation reveals that a test case can have explicit test-oriented entities, such as tested function Components, Constraints, etc; and there are also specific relations between these entities. This inspires us with a potential opportunity for accurate redundancy detection. In this paper, we first define five test-oriented entity categories and four associated relation categories and re-formulate the NL test case redundancy detection problem as the comparison of detailed testing content guided by the test-oriented entities and relations. Following that, we propose Tscope, a fine-grained approach for redundant NL test case detection by dissecting test cases into atomic test tuple(s) with the entities restricted by associated relations. To serve as the test case dissection, Tscope designs a context-aware model for the automatic entity and relation extraction. Evaluation on 3,467 test cases from ten projects shows Tscope could achieve 91.8% precision, 74.8% recall, and 82.4% F1, significantly outperforming state-of-the-art approaches and commonly-used classifiers. This new formulation of the NL test case redundant detection problem can motivate the follow-up studies to further improve this task and other related tasks involving NL descriptions.Comment: 12 pages, 6 figures, to be published in ESEC/FSE 2

Formalising responsibility modelling for automatic analysis

Modelling the structure of social-technical systems as a basis for informing software system design is a difficult compromise. Formal methods struggle to capture the scale and complexity of the heterogeneous organisations that use technical systems. Conversely, informal approaches lack the rigour needed to inform the software design and construction process or enable automated analysis. We revisit the concept of responsibility modelling, which models social technical systems as a collection of actors who discharge their responsibilities, whilst using and producing resources in the process. Responsibility modelling is formalised as a structured approach for socio-technical system requirements specification and modelling, with well-defined semantics and support for automated structure and validity analysis. The effectiveness of the approach is demonstrated by two case studies of software engineering methodologies

Memory built-in self-repair and correction for improving yield: a review

Nanometer memories are highly prone to defects due to dense structure, necessitating memory built-in self-repair as a must-have feature to improve yield. Today’s system-on-chips contain memories occupying an area as high as 90% of the chip area. Shrinking technology uses stricter design rules for memories, making them more prone to manufacturing defects. Further, using 3D-stacked memories makes the system vulnerable to newer defects such as those coming from through-silicon-vias (TSV) and micro bumps. The increased memory size is also resulting in an increase in soft errors during system operation. Multiple memory repair techniques based on redundancy and correction codes have been presented to recover from such defects and prevent system failures. This paper reviews recently published memory repair methodologies, including various built-in self-repair (BISR) architectures, repair analysis algorithms, in-system repair, and soft repair handling using error correcting codes (ECC). It provides a classification of these techniques based on method and usage. Finally, it reviews evaluation methods used to determine the effectiveness of the repair algorithms. The paper aims to present a survey of these methodologies and prepare a platform for developing repair methods for upcoming-generation memories

A machine learning-based approach to optimize repair and increase yield of embedded flash memories in automotive systems-on-chip

Nowadays, Embedded Flash Memory cores occupy a significant portion of Automotive Systems-on-Chip area, therefore strongly contributing to the final yield of the devices. Redundancy strategies play a key role in this context; in case of memory failures, a set of spare word- and bit-lines are allocated by a replacement algorithm that complements the memory testing procedure. In this work, we show that replacement algorithms, which are heavily constrained in terms of execution time, may be slightly inaccurate and lead to classify a repairable memory core as unrepairable. We denote this situation as Flash memory false fail. The proposed approach aims at identifying false fails by using a Machine Learning approach that exploits a feature extraction strategy based on shape recognition. Experimental results carried out on the manufacturing data show a high capability of predicting false fails

NASA Tech Briefs Index, 1977, volume 2, numbers 1-4

Announcements of new technology derived from the research and development activities of NASA are presented. Abstracts, and indexes for subject, personal author, originating center, and Tech Brief number are presented for 1977

Index to NASA tech briefs, 1971

The entries are listed by category, subject, author, originating source, source number/Tech Brief number, and Tech Brief number/source number. There are 528 entries

The assessment of posture and balance post-stroke

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Physiotherapy for people with stroke has been found to be beneficial but details of the most effective interventions are unclear. Further development of the evidence base for stroke physiotherapy is limited by a lack of clinical practice models, sensitive clinically based outcome measures and effective stratification techniques to characterise homogenous groups of subjects. These issues are addressed here with regard to balance and posture. These aspects were chosen because they form a cornerstone of stroke physiotherapy as they are thought essential for the rehabilitation of functional activities. A systematic review of assessment methods in the literature revealed a lack of measurement tools which met the utility criteria: reliability, validity, sensitivity to short-term change, suitability for a wide range of abilities, ease of use and suitability for different settings. This prompted the development of a new measurement tool. Firstly, a model of the clinical assessment process was developed using an adapted focus group method with neurological physiotherapists. This informed the content of a new measurement tool which combined an ordinal scale with functional performance tests- the Brunel Balance Assessment. The tool was evaluated in a series of studies involving 92 stroke patients. It was hierarchical (coefficient of reproducibility= 0.99, coefficient of scalability = 0.69), reliable (100% agreement) and valid as a measure of balance disability (r=0.58-0.97). The psychometric properties of the individual functional performance tests were also tested and found to be reliable (ICCs =0.88-1) and valid (r=0.32-0.63). Measurement error ranged 0-40% and the minimum change needed to detect true clinical change was calculated for each test. Balance disability, measured with the Brunel Balance Assessment, is heterogeneous with sitting, standing and stepping balance forming distinct levels of ability (p<0.027). Consequently, the BBA could be used to stratify people with stroke according to balance ability. Weakness, sensation and age were significant independent contributors to balance disability (r2=82.7%). Balance ability was a strong contributor to independence in ADL (p<0.0001). The findings of this thesis address the issues that have limited research into stroke physiotherapy with regard to balance disability. In relation to clinical practice, a robust measurement and stratification tool has been developed.Department of Health Studies, Brunel University and the Brunel University Research Enterpris