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The basic emission process associated with positron emission tomography (PET) imaging is Poisson in nature. Reconstructed images inherit some aspects of this—regional variability is typically proportional to the regional mean. Iterative reconstruction using expectation–maximization (EM), widely used in clinical imaging now, imposes positivity constraints that impact noise properties. This paper is motivated by the analysis of data from a physical phantom study of a PET/CT scanner in routine clinical use. Both traditional filtered back-projection (FBP) and EM reconstructions of the images are considered. FBP images are quite Gaussian, but the EM reconstructions exhibit Gamma-like skewness. The Gamma structure has implications for how reconstructed PET images might be processed statistically. Post-reconstruction inference—model fitting and diagnostics for regions of interest are of particular interest. Although the relevant Gamma parameterization is not within the framework of generalized linear models (GLM), iteratively re-weighted least squares (IRLS) techniques, which are often used to find the maximum likelihood estimates of a GLM, can be adapted for analysis in this setting. This paper highlights the use of a Gamma-based probability transform in producing normalized residuals as model diagnostics. The approach is demonstrated for quality assurance analyses associated with physical phantom studies—recovering estimates of local bias and variance characteristics in an operational scanner. Numerical simulations show that when the Gamma assumption is reasonable, gains in efficiency are obtained. This paper shows that the adaptation of standard analysis methods to accommodate the Gamma structure is straightforward and beneficial. [ABSTRACT FROM PUBLISHER]

This paper presents the optimization of an existing electrically eraseable programmable read-only memory (EEPROM) production test flow by means of thorough analysis of the faulty dice and the test flow, which leads to an increase in the yield, a significant decrease in test time, and a decrease in the dppm (increase in quality) level leaving the factory. In order to manufacture high quality and cost-effective EEPROMs suitable for automotive underhood applications, several topics must be taken into account. In addition to a high reliability EEPROM technology, the choice of an advanced memory architecture including error correction code and a highly sophisticated screening methodology in production test is necessary to achieve high quality in the field. The EEPROM production test flow must not only be able to screen out weaknesses in the process but must also be cost efficient. A majority of the tests executed in the EEPROM test flow are needed to check the quality of the processed oxides, which are the basic elements to realize the EEPROM function of the memory. Most of these tests are complex and time-consuming. [ABSTRACT FROM PUBLISHER]

Characterization of the noise distribution in magnetic resonance images has multiple applications, including quality assurance and protocol optimization. Noise characterization is particularly important in the presence of parallel imaging acceleration with multi-coil acquisitions, where the noise distribution can contain severe spatial heterogeneities. If the parallel imaging reconstruction is a linear process, an accurate noise analysis can be carried out by taking into account the correlations between all the samples involved. However, for k -space-based techniques such as generalized autocalibrating partially parallel acquisition (GRAPPA), the exact analysis has been considered computationally prohibitive due to the very large size of the noise covariance matrices required to characterize the noise propagation from k -space to image space. Previously proposed methods avoid this computational burden by formulating the GRAPPA reconstruction as a pixel-wise linear operation performed in the image space. However, these methods are not exact in the presence of non-uniform sampling of k -space (e.g., containing a calibration region). For this reason, in this paper, we develop an accurate characterization of the noise distribution for self-calibrated parallel imaging in the presence of arbitrary Cartesian sampling patterns. By exploiting the symmetries and separability in the noise propagation process, the proposed method is computationally efficient and does not require large matrices. Under the assumption of a fixed reconstruction kernel, this method provides the precise distribution of the noise variance for each coil’s image. These coil-by-coil noise maps are subsequently combined according to the coil combination approach used in image reconstruction, and therefore can be applied with both complex coil combination and root-sum-of-squares approaches. In this paper, we present the proposed noise characterization method and compare it to previous techniques using Monte Carlo simulations as well as phantom acquisitions. [ABSTRACT FROM PUBLISHER]

In this paper, two metrics for measuring image sharpness are presented and used for an autofocus (AF) application. Both measures exploit reorganized discrete cosine transform (DCT) representation. The first metric is a focus measure, which involves optimal high- and middle-frequency coefficients to evaluate relative sharpness. It is robust to noise while remaining sensitive to the best focus position. A psychometric function-based metric is introduced to quantify the focus measure. The second metric is a no-reference blurriness metric, which is used to measure absolute blurriness. It first constructs multiscale DCT edge maps using directional energy information and then determines image blurriness by combining change information in edge structures with image contrast. This metric gives predictions that are closely correlated with subjective perceived scores and shows performance comparable with that of state-of-the-art methods, especially for noisy images. For noisy situations, the two metrics are adjusted adaptively according to the estimated noise level. To prevent the introduction of extra computational load, an efficient noise-level estimation algorithm based on median absolute deviation is presented. This algorithm exploits only the available reorganized DCT coefficients. With the focus and blurriness measures, an AF method for which the two metrics play an important role was developed. Because of their high-quality performance, the realized AF function is able to locate the best focus position swiftly and reliably. [ABSTRACT FROM PUBLISHER]

In this paper, an analysis on the suitability of employing a colorimetric analysis of the acquired plasma spectra to perform on-line arc-welding quality monitoring will be discussed. Different colorimetric parameters like the color temperature or the parameters associated with the hue, saturation, luminance color space will be evaluated in comparison with the standard approach based on the estimation of the plasma electronic temperature. This approach does not require the identification of the emission lines involved in the analysis, thus giving rise to a more efficient solution in terms of computational efficiency, and avoiding unambiguous identifications that may give rise to incorrect results. In particular, experimental tests performed with a tungsten inert gas arc-welding process will show the feasibility of using the proposed solution and its ability to perform an online detection of different welding perturbations. [ABSTRACT FROM PUBLISHER]

Introduces a special issue of the magazine 'IEEE Transactions on Software Engineering' (TSE) that features papers presented at the 2001 Workshop on Inspection in Software Engineering. Reasons behind the decision to feature the workshop papers in linked special issues of TSE and 'IEEE Software Magazine'; Definition of software inspection; Benefits of inspection.

In "Automated Test Systems Test Program Software-The Invisible Technology" we indicated that the amount of work associated to Test Program Set (TPS) development, maintenance, and migration in the Department of Defense (DOD) has grown significantly [1]. In the paper, we proposed a model for a TPS developer's certification plan, training program, and Quality Assurance management plan. This paper is a continuation of that original work. It will take a deeper look into one area: TPS Quality Assurance. Development of successful test program sets for Automated Test Systems (ATS) is enhanced by timely application of proven management procedures such as quality control plans, design reviews, change control procedures. It is also enhanced by controls over cost, schedule, development, deployment, and end item configuration. This paper is devoted to a general discussion of management and technical procedures, plans, tests, and reports that are applicable to assuring quality throughout development and delivery of the TPS. [ABSTRACT FROM AUTHOR]

The quantification of muscle weakness is useful to evaluate the health status and performance of patients and athletes. In this paper, we proposed a novel methodology to investigate and to quantify the effects induced by inaccuracy sources occurring when using a hand-held dynamometer (HHD) for knee strength measurements. The validation methodology is based on the comparison between the output of a one-component commercial HHD and the outputs of a six-component load cell, comparable in dimension and mass. An optoelectronic system was used to measure HHD positioning angles and displacements. The setup allowed to investigate the effects induced by: 1) the operator’s ability to place and to hold still the HHD and 2) ignoring the transversal components of the force exchanged. The main finding was that the use of a single component HHD induced an overall inaccuracy of 5% in the strength measurements if the angular misplacements are kept within the values found in this paper (≤15°) and with a knee range of motion ≤22°. Extension trials were the most critical due to the higher force exerted, i.e., 249.4 ± 27.3 versus 146.4 ± 23.9 N of knee flexion. The most relevant source of inaccuracy was identified in the angular displacement on the horizontal plane. [ABSTRACT FROM PUBLISHER]

In the process of developing an infrastructure for providing visualization and visual analytics (VIS) tools to epidemiologists and modeling scientists, we encountered a technical challenge for applying a number of visual designs to numerous datasets rapidly and reliably with limited development resources. In this paper, we present a technical solution to address this challenge. Operationally, we separate the tasks of data management, visual designs, and plots and dashboard deployment in order to streamline the development workflow. Technically, we utilize: an ontology to bring datasets, visual designs, and deployable plots and dashboards under the same management framework; multi-criteria search and ranking algorithms for discovering potential datasets that match a visual design; and a purposely-design user interface for propagating each visual design to appropriate datasets (often in tens and hundreds) and quality-assuring the propagation before the deployment. This technical solution has been used in the development of the RAMPVIS infrastructure for supporting a consortium of epidemiologists and modeling scientists through visualization. [ABSTRACT FROM AUTHOR]

Task allocation is a fundamental research issue in mobile crowd sensing. While earlier research focused mainly on single tasks, recent studies have started to investigate multi-task allocation, which considers the interdependency among multiple tasks. A common drawback shared by existing multi-task allocation approaches is that, although the overall utility of multiple tasks is optimized, the sensing quality of individual tasks may become poor as the number of tasks increases. To overcome this drawback, we re-define the multi-task allocation problem by introducing task-specific minimal sensing quality thresholds, with the objective of assigning an appropriate set of tasks to each worker such that the overall system utility is maximized. Our new problem also takes into account the maximum number of tasks allowed for each worker and the sensor availability of each mobile device. To solve this newly-defined problem, this paper proposes a novel multi-task allocation framework named MTasker. Different from previous approaches which start with an empty set and iteratively select task-worker pairs, MTasker adopts a descent greedy approach, where a quasi-optimal allocation plan is evolved by removing a set of task-worker pairs from the full set. Extensive evaluations based on real-world mobility traces show that MTasker outperforms the baseline methods under various settings, and our theoretical analysis proves that MTasker has a good approximation bound. [ABSTRACT FROM AUTHOR]

There has been a long pursuit for precise and reproducible glomerular quantification on renal pathology to leverage both research and practice. When digitizing the biopsy tissue samples using whole slide imaging (WSI), a set of serial sections from the same tissue can be acquired as a stack of images, similar to frames in a video. In radiology, the stack of images (e.g., computed tomography) are naturally used to provide 3D context for organs, tissues, and tumors. In pathology, it is appealing to do a similar 3D assessment. However, the 3D identification and association of large-scale glomeruli on renal pathology is challenging due to large tissue deformation, missing tissues, and artifacts from WSI. In this paper, we propose a novel Multi-object Association for Pathology in 3D (Map3D) method for automatically identifying and associating large-scale cross-sections of 3D objects from routine serial sectioning and WSI. The innovations of the Multi-Object Association for Pathology in 3D (Map3D) method are three-fold: (1) the large-scale glomerular association is formed as a new multi-object tracking (MOT) perspective; (2) the quality-aware whole series registration is proposed to not only provide affinity estimation but also offer automatic kidney-wise quality assurance (QA) for registration; (3) a dual-path association method is proposed to tackle the large deformation, missing tissues, and artifacts during tracking. To the best of our knowledge, the Map3D method is the first approach that enables automatic and large-scale glomerular association across 3D serial sectioning using WSI. Our proposed method Map3D achieved MOTA = 44.6, which is 12.1% higher than the non-deep learning benchmarks. [ABSTRACT FROM AUTHOR]

Hospitals often set protocols based on well defined standards to maintain the quality of patient reports. To ensure that the clinicians conform to the protocols, quality assurance of these reports is needed. Patient reports are currently written in free-text format, which complicates the task of quality assurance. In this paper, we present a machine learning based natural language processing system for automatic quality assurance of radiology reports on breast cancer. This is achieved in three steps: we i) identify the top-level structure (headings) of the report, ii) classify the report content into the top-level headings, and iii) convert the free-text detailed findings in the report to a semi-structured format (post-structuring). Top level structure and content of report were predicted with an F1 score of 0.97 and 0.94, respectively, using Support Vector Machine (SVM) classifiers. For automatic structuring, our proposed hierarchical Conditional Random Field (CRF) outperformed the baseline CRF with an F1 score of 0.78 versus 0.71. The determined structure of the report is represented in semi-structured XML format of the free-text report, which helps to easily visualize the conformance of the findings to the protocols. This format also allows easy extraction of specific information for other purposes such as search, evaluation, and research. [ABSTRACT FROM AUTHOR]

Previous research in defect prediction has proposed approaches to determine which files require additional testing resources. However, practitioners typically create tests at a higher level of abstraction, which may span across many files. In this paper, we study software testing, especially test resource prioritization, from a different perspective. We use topic models to generate topics that provide a high-level view of a system, allowing developers to look at the test case coverage from a different angle. We propose measures of how well tested and defect prone a topic is, allowing us to discover which topics are well tested and which are defect prone. We conduct case studies on the histories of Mylyn, Eclipse, and NetBeans. We find that 34–78% of topics are shared between source code and test files, indicating that we can use topic models to study testing; well-tested topics are usually less defect prone, defect-prone topics are usually undertested; we can predict which topics are defect prone but not well tested with an average precision and recall of 75% and 77%, respectively; our approach complements traditional prediction-based approaches by saving testing and code inspection effort; and our approach is not particularly sensitive to the parameters that we use. [ABSTRACT FROM PUBLISHER]

The premise of variability-intensive systems, specifically in software product line engineering, is the ability to produce a large family of different systems efficiently. Many such systems are critical. Thorough quality assurance techniques are thus required. Unfortunately, most quality assurance techniques were not designed with variability in mind. They work for single systems, and are too costly to apply to the whole system family. In this paper, we propose an efficient automata-based approach to linear time logic (LTL) model checking of variability-intensive systems. We build on earlier work in which we proposed featured transitions systems (FTSs), a compact mathematical model for representing the behaviors of a variability-intensive system. The FTS model checking algorithms verify all products of a family at once and pinpoint those that are faulty. This paper complements our earlier work, covering important theoretical aspects such as expressiveness and parallel composition as well as more practical things like vacuity detection and our logic feature LTL. Furthermore, we provide an in-depth treatment of the FTS model checking algorithm. Finally, we present SNIP, a new model checker for variability-intensive systems. The benchmarks conducted with SNIP confirm the speedups reported previously. [ABSTRACT FROM AUTHOR]

As a result of their involvement in several research and development and innovation (R&D&I) projects developed in various companies, the authors acquired knowledge of two basic concepts: quality and innovation. The application of these concepts in the teaching–learning process can help teachers to incorporate informal changes in the curriculum to provide for continuous improvement. This paper presents a simple methodology to apply quality and innovation concepts and tools in the daily teaching activity. In order to show the ease of use, as well as the efficiency and effectiveness of this methodology, the experience of applying it in an engineering course over nine years, the actions undertaken, the results obtained, and the lessons learned are described here. The methodology incorporates reflection, innovation, and decision taking based on objective data. Contact with the companies involved has enabled the teachers to learn continuously and to enhance their motivation when working with students. The methodology applied and the example described in this paper can be a starting point for other teachers interested in improving the quality of their teaching. [ABSTRACT FROM AUTHOR]

In this paper, we present an application of machine learning to distinguish between different materials based on their surface texture. Such a system can be used for the estimation of surface friction during manipulation tasks; quality assurance in the textile, cosmetics, and harvesting industries; and other applications requiring tactile sensing. Several machine learning algorithms, such as naive Bayes, decision trees, and naive Bayes trees, have been trained to distinguish textures sensed by a biologically inspired artificial finger. The finger has randomly distributed strain gauges and polyvinylidene fluoride (PVDF) films embedded in silicone. Different textures induce different intensities of vibrations in the silicone. Consequently, textures can be distinguished by the presence of different frequencies in the signal. The data from the finger are preprocessed, and the Fourier coefficients of the sensor outputs are used to train classifiers. We show that the classifiers generalize well for unseen datasets with performance exceeding previously reported algorithms. Our classifiers can distinguish between different materials, such as carpet, flooring vinyls, tiles, sponge, wood, and polyvinyl-chloride (PVC) woven mesh with an accuracy of 95\%\pm 4\% on unseen test data. [ABSTRACT FROM AUTHOR]

Quality assurance (QA) testing of mass-produced electrical appliances is critical for the reputation of manufacturer since defective units will have a negative impact on safety, reliability, efficiency, and performance of the end product. It has been observed at a brushless dc (BLDC) compressor motor manufacturing facility that improper magnetization of the rotor permanent magnet is one of the leading causes of motor defects. A new technique for postmanufacturing assessment of the magnetization quality of concentrated winding BLDC compressor motors for QA is proposed in this paper. The new method evaluates the data acquired during the test runs performed after motor assembly to observe anomalies in the zero-crossing pattern of the back-EMF voltages for screening motor units with defective magnetization. An experimental study on healthy and defective 250-W BLDC compressor motor units shows that the proposed technique provides sensitive detection of magnetization defects that existing tests were not capable of finding. The proposed algorithm does not require additional hardware for implementation since it can be added to the existing test-run inverter of the QA system as a software algorithm. [ABSTRACT FROM AUTHOR]

In many flexible manufacturing systems, batch production is often adopted to improve product quality. For example, in automotive paint shops, vehicles with same colors are typically grouped into small batches to reduce quality degradation and purge cost due to color change. In this paper, we present an analytical method to evaluate the quality performance of flexible manufacturing systems with batch operations. In addition, we investigate the impact of product sequencing and batch policies on product quality and present some insights to achieve better quality using these policies. [ABSTRACT FROM PUBLISHER]

This paper carries an extensive evaluation on the performance of a generalized motif-based method for detecting defects in 16 out of 17 wallpaper groups in 2-D patterned texture. The motif-based method evolves from the concept that every wallpaper group is defined by a lattice, which contains a further constituent-motif. It utilizes the symmetry properties of motifs to calculate the energy of moving subtraction and its variance among motifs. Decision boundaries are determined by learning the distribution of those values among the defect-free and defective patterns in the energy-variance space. In this paper, shape transform for irregular motif has been demonstrated according to the three basic motif shapes: rectangle, triangle, and parallelogram. An error analysis for the misclassifications has also been delivered. In the database of fabrics and other patterned textures, a total of 381 defect-free lattices are used for formulation of boundaries while further 340 defect-free and 233 defective lattices are for testing. The motif-based method has a consistent result and reaches a detection success rate of 93.86%. Note to Practitioners-This paper is motivated by the need to develop a generalized approach that can detect defects on most of the 2-D patterned textures defined so far. It proposes a novel motif-based defect detection method for 16 out of 17 wallpaper groups. A new concept called energy of moving subtraction is defined using norm metric measurement between a collection of circular shift matrices of motif and itself. Together with its variance, an energy-variance space is defined where decision boundaries are drawn for classifying defective and defect-free motifs. The method has been evaluated by two categories of patterned textures. The first category is produced from patterned fabric samples from p2, pmm, p4m, pm, and cm groups. The second category is produced from various patterned texture samples from p4, pg, pmg, cmm, p4g, pgg, p31m, p6, p6m, and p3m1 groups. For the former, a total of 280 defect-free lattices samples are used for deriving the decision boundaries, and further 340 defect-free and 206 defective lattices are used for evaluation. The detection success rate is found to be 93.92%. For the latter, they are the images from painting, tile, ornament, painted porcelain, vessel, earthenware, mat, tapestry, cloth, and wall tiling. A total of 101 defect-free lattices are acquired and 27 defective lattices are used for defect detection. The detection success rate for the second category is 92.59%. An overall detection success rate of 93.86% is achieved for the motif-based method. No other (generalized) approach was able to handle such a large number of wallpaper groups of 2-D patterned textures, and hence this result outperforms all other previously published approaches. This result contributes to the quality assurance of production of textile, wallpaper, ceramics, ornament, and tile. [ABSTRACT FROM AUTHOR]

This paper presents a novel method for lithium-ion battery electrode (LIBE) surface quality assurance. First, based on machine vision, an automatic optical inspection system is developed to check defects on LIBE. In addition, a background normalization algorithm is put forward to preprocess the large-scale LIBE with inhomogeneous thickness in uneven illumination. With the help of the auto-concentration compensation algorithm, flaws can be extracted precisely. Moreover, after characterizing the defects, features machine applied partiality parameter automatic adjustment method and partiality decision rules are exerted for defects accurate classification, which provides near-optimal performance and reduces the complexity of tuning parameters. The proposed method is computationally efficient and satisfies real-time online inspection requirement. Experimental results verify the effectiveness and performance of the proposed method according to the inspection speed and recognition rate. [ABSTRACT FROM AUTHOR]

Traditional assurance solutions for software-based systems rely on static verification techniques and assume continuous availability of trusted third parties. With the advent of cloud computing, these solutions become ineffective since services/applications are flexible, dynamic, and change at runtime, at high rates. Although several assurance approaches have been defined, cloud requires a step-change moving current assurance techniques to fully embrace the cloud peculiarities. In this paper, we provide a rigorous and adaptive assurance technique based on certification, towards the definition of a transparent and trusted cloud ecosystem. It aims to increase the confidence of cloud customers that every piece of the cloud (from its infrastructure to hosted applications) behaves as expected and according to their requirements. We first present a test-based certification scheme proving non-functional properties of cloud-based services. The scheme is driven by non-functional requirements defined by the certification authority and by a model of the service under certification. We then define an automatic approach to verification of consistency between requirements and models, which is at the basis of the chain of trust supported by the certification scheme. We also present a continuous certificate life cycle management process including both certificate issuing and its adaptation to address contextual changes. Finally, we describe our certification framework and an experimental evaluation of its performance, quality, applicability, and practical usability in a real industrial scenario, which considers Engineering Ingegneria Informatica S.p.A. ENGpay online payment system. [ABSTRACT FROM AUTHOR]

In a previous paper a new technique was proposed to allow real-time, online operation for arc-welding quality assurance based on plasma spectroscopy. In this paper, the proposed system has been used to determine the appearance of weld defects in the arc-welding nuclear steam generator tube-to-tubesheet process. The system was implemented in the facilities of Equipos Nucleares S.A. (ENSA), where several welding tests were performed on weld test coupons. Results will show the feasibility of the proposed system to be used in a real industrial scenario, presenting successful examples of weld defect detections. [ABSTRACT FROM PUBLISHER]

Multicenter clinical trials are complex undertakings that require significant resources to ensure efficient, high quality research. This paper describes the goals, design, and implementation of a multicenter clinical trial database management system to support this aim. A large number of study sites or patients, and the goal of automatically generating large portions of data management infrastructure from common metadata, motivated the development of the system. This paper also describes extensions for a generalized project documentation system, and discusses plans for further extensions and improvements based on observed strengths, limitations, and anticipated technological change. [ABSTRACT FROM AUTHOR]

Advanced process technologies have been introducing many unseen problems on process yield and device reliability. Microcontamination, which enables defects causing electric faults, has also been hard to understand, detect, and control. In this paper, the requirements and methodologies for contamination control in advanced technologies such as at the 90-nm processing technology node and immersion lithography using 300-mm wafer processing were addressed. Combining techniques of vapor phase decomposition (VPD) and wafer outgassing system (WOS) for characterizing the very low levels of surface metallic and organic contaminants on 300-mm wafers makes a front-end process capable of realizing and deploying the necessary controls. Applying liquid chromatography-mass spectrometry (LC-MS) in the identification of contaminants of immersion fluids is a new experience for 193-nm lithography technology. Furthermore, the wafer-environment contamination controls, such as airborne molecular contaminants (AMCs), process critical material assurance and point-of-use quality are reviewed in the paper. This paper concludes by discussing the challenges for characterization and control of microcontamination in future manufacturing technologies. [ABSTRACT FROM PUBLISHER]

This paper presents an overview an inverters developed for small distributed power generators. The functions of inverters in distributed power generation (DG) systems include dc-ac conversion, output power quality assurance, various protection mechanisms, and system controls. Unique requirements for small distributed power generation systems include low cost, high efficiency and tolerance for an extremely wide range of input voltage variations. These requirements have driven the inverter development toward simpler topologies and structures, lower component counts and tighter modular design. Both single-stage and multiple-stage inverters have been developed for power conversion in DG systems. single-stage Inverters offer simple structure and low cost, but suffer from a limited range of input voltage variations and are often characterized by compromised system performance. On the other hand, multiple-stage inverters accept a wide range of input voltage variations, but suffer from high cost, complicated structure and low efficiency. Various circuit topologies are presented, compared, and evaluated against the requirements of power decoupling and dual-grounding, the capabilities for grid-connected or/and standalone operations, and specific DG applications in this paper, along with the identification of recent development trends of single-phase inverters for distributed power generators. [ABSTRACT FROM AUTHOR]

In this paper, an on-line bending loss measurement system is studied and realized. To avoid complicated calculation of fiber bending loss, we propose a simplified theoretical model for on-line evaluation. A specific fiber adaptor is developed for light signal feeding and picking up through a free space optical fiber coupling technique. Relevant factors including free space fiber misalignment are considered. The signal-to-noise ratio of the whole system is improved by optimizing the spatial perturbation length of the fiber and the deformation of the bending fiber. The use of an on-line monitoring technique for measuring bending loss of optical fiber is presented in this paper. With this technique, manufacturing efficiency can be improved, and the cost of maintaining fiber quality control can be reduced. [ABSTRACT FROM AUTHOR]

Changing software to implement new features, correct problems, update functions, or replace obsolete hardware components (e.g., microprocessors) is a way of life in today's industry. A systematic software change process is essential for the maintenance and reuse of safety-critical software. This paper presents activities to consider when changing software in safety-critical systems. The focus is on the aviation industry; however, the concepts are also applicable to other safety-critical domains, such as medical or nuclear [ABSTRACT FROM PUBLISHER]

At the Centre for Proton Therapy at the Paul Scherrer Institute, cancer patients are treated with a fixed beamline and in two gantries for ocular and nonocular malignancies, respectively. For the installation of a third gantry, a new patient safety system (PaSS) was developed and is subsequently being rolled out to update the existing areas. The aim of the PaSS is to interrupt the treatment whenever any subsystem detects a hazardous condition. To ensure correct treatment delivery, this system needs to be thoroughly tested as part of the regular quality assurance (QA) protocols as well as after any upgrade. In the legacy safety systems, unit testing required extensive use of resources: 2 weeks of work per area in the laboratory in addition to QA beam time. In order to significantly reduce the time, an automated PaSS test stand for unit testing was developed based on a PCI eXtensions for Instrumentation chassis with virtually unlimited I/Os that are synchronously stimulated or sampled at 1 MHz. It can emulate the rest of the facility using adapters to connect each type of interface. With it, the PaSS can be tested under arbitrary conditions. A VHSIC (very high speed integrated circuit) hardware description language-based formal language was developed to describe stimuli, expected behavior, and specific measurements, interpreted by a LabView runtime environment. This paper describes the tools and methodology being applied for unit testing and QA release tests for the new PaSS. It shows how automation and formalization made possible to increase the test coverage while significantly reducing the laboratory testing time and facility’s beam usage. [ABSTRACT FROM AUTHOR]

Testing scientific software is a difficult task due to their inherent complexity and the lack of test oracles. In addition, these software systems are usually developed by end-user developers who are not normally trained as professional software developers nor testers. These factors often lead to inadequate testing. Metamorphic testing (MT) is a simple yet effective testing technique for testing such applications. Even though MT is a wellknown technique in the software testing community, it is not very well utilized by the scientific software developers. The objective of this paper is to present MT as an effective technique for testing scientific software. To this end, we discuss why MT is an appropriate testing technique for scientists and engineers who are not primarily trained as software developers. Specifically, how it can be used to conduct systematic and effective testing on programs that do not have test oracles without requiring additional testing tools. [ABSTRACT FROM AUTHOR]

The world's increased dependence on software-enabled systems has raised major concerns about software reliability and security. New cost-effective tools for software quality assurance are needed. This paper presents an automated test generation technique, called Model-based Integration and System Test Automation (MISTA), for integrated functional and security testing of software systems. Given a Model-Implementation Description (MID) specification, MISTA generates test code that can be executed immediately with the implementation under test. The MID specification uses a high-level Petri net to capture both control- and data-related requirements for functional testing, access control testing, or penetration testing with threat models. After generating test cases from the test model according to a given criterion, MISTA converts the test cases into executable test code by mapping model-level elements into implementation-level constructs. MISTA has implemented test generators for various test coverage criteria of test models, code generators for various programming and scripting languages, and test execution environments such as Java, C, C++, C#, HTML-Selenium IDE, and Robot Framework. MISTA has been applied to the functional and security testing of various real-world software systems. Our experiments have demonstrated that MISTA can be highly effective in fault detection. [ABSTRACT FROM PUBLISHER]

The X-ray diffraction (XRD) analysis of cement process materials has grown beyond its roots in the laboratory to become an important tool for process control. Combined with its partners, i.e., X-ray fluorescence (XRF) and controlled neutron analysis (CNA), these techniques can provide valuable process control information, i.e., essentially “new eyes”, to guide process control decisions. Important developments in XRD analyzers have decreased analysis time from hours to minutes to provide quick results that enable timely process control decisions. XRD phase analysis can provide information to optimize combustion control and mix chemistry, cooler operation, and additive mixtures in finish cement. This paper will provide an overview of all the XRF/XRD applications and then focus on the XRD process control opportunities. [ABSTRACT FROM AUTHOR]

Crowdsourcing systems often have crowd workers that perform unreliable work on the task they are assigned. In this paper, we propose the use of error-control codes and decoding algorithms to design crowdsourcing systems for reliable classification despite unreliable crowd workers. Coding theory based techniques also allow us to pose easy-to-answer binary questions to the crowd workers. We consider three different crowdsourcing models: systems with independent crowd workers, systems with peer-dependent reward schemes, and systems where workers have common sources of information. For each of these models, we analyze classification performance with the proposed coding-based scheme. We develop an ordering principle for the quality of crowds and describe how system performance changes with the quality of the crowd. We also show that pairing among workers and diversification of the questions help in improving system performance. We demonstrate the effectiveness of the proposed coding-based scheme using both simulated data and real datasets from Amazon Mechanical Turk, a crowdsourcing microtask platform. Results suggest that use of good codes may improve the performance of the crowdsourcing task over typical majority-voting approaches. [ABSTRACT FROM PUBLISHER]

During software maintenance and evolution the internal structure of the software system undergoes continuous changes. These modifications drift the source code away from its original design, thus deteriorating its quality, including cohesion and coupling of classes. Several refactoring methods have been proposed to overcome this problem. In this paper we propose a novel technique to identify Move Method refactoring opportunities and remove the Feature Envy bad smell from source code. Our approach, coined as Methodbook, is based on relational topic models (RTM), a probabilistic technique for representing and modeling topics, documents (in our case methods) and known relationships among these. Methodbook uses RTM to analyze both structural and textual information gleaned from software to better support move method refactoring. We evaluated Methodbook in two case studies. The first study has been executed on six software systems to analyze if the move method operations suggested by Methodbook help to improve the design quality of the systems as captured by quality metrics. The second study has been conducted with eighty developers that evaluated the refactoring recommendations produced by Methodbook. The achieved results indicate that Methodbook provides accurate and meaningful recommendations for move method refactoring operations. [ABSTRACT FROM PUBLISHER]

The recent trend in squirrel cage induction motor manufacturing is to replace fabricated copper rotors with aluminum die-cast rotors to reduce manufacturing cost to stay competitive in the global market. Porosity in aluminum die-cast squirrel cage rotors is inevitably introduced during the die cast process. Porosity can cause degradation in motor performance and can lead to a forced outage causing irreversible damage in extreme cases. Many offline and online quality assurance test methods have been developed and applied for assessment of rotor quality. However, years of experience with the existing test methods revealed that they are not suitable for quality testing or capable of providing a quantitative assessment of rotor porosity with sufficient sensitivity. In this paper, a new offline test method capable of providing sensitive assessment of rotor porosity is proposed. It is shown that rotors with minor and distributed porosity that are difficult to detect with other tests can be screened out during manufacturing. The proposed method is verified through a 3-D finite element analysis and experimental testing on closed and semiopen slot aluminum die cast rotors of 5.5 kW induction motors with porosity. [ABSTRACT FROM PUBLISHER]

The SIS100, a novel heavy ion synchrotron, is the main accelerator of the FAIR complex (Facility for Antiproton and Ion Research), which is currently being constructed in Darmstadt, Germany. Over 400 superconducting magnets have been contracted either at industry or by collaboration partners. In order to fulfil the requirements for quality assurance, the magnets will be intensively tested at ambient and cryogenic conditions. The testing campaign considers mechanical dimension control (including the height of the yoke's gap), electrical tests, and measurements of the magnetic field induction. Two new test facilities were built for the sake of superconducting magnet testing. The first facility is located at the GSI Helmholtzzentrum f ür Schwerionenforschung GmbH, Darmstadt, Germany. The object is constructed to provide a comprehensive testing program dedicated to series dipole cryomodules. The second test facility is located at the Joint Institute for Nuclear Research (JINR), Dubna, Russian Federation, where quadrupole and corrector magnets are going to be tested. This paper presents the status report concerning the magnet production, testing strategy, and capability and extent of development of the test stations. [ABSTRACT FROM AUTHOR]

The general and detailed design of the JT-60SA toroidal field (TF) coil system was done by all the Voluntary Contributors in the project, CEA, ENEA, and F4E. The French part including the supply of 9 + 1 spare of the 18 TF winding packs and their integration in casings was entrusted mid-2011 to Alstom (Belfort, France), now General Electric. Manufacturing flow definition, drawings, and quality assurance documentation were achieved prior qualification of the critical processes. The procurement and commissioning of the needed tooling was led in parallel and the production was started in January 2014. The first winding pack was ready in the end of 2014. The integration inside the casing started in March 2015 for coil completion end 2015. Then, the coil was delivered to the coil test facility for testing at nominal operation condition (T = 4.5 K, I = 25, 7 kA) and for qualifying the coil resilience to quench events. In parallel, the successive coils were engaged in the manufacture process. The paper reports the status of the manufacture and gives a feedback on the main issues and on the technical solutions implemented. A focus is made on the mastering of the manufacturing processes, which is highlighted by the learning curve of the TF coils manufacturing. [ABSTRACT FROM AUTHOR]

Until now, various techniques for predicting fault-prone modules have been proposed and evaluated in terms of their prediction performance; however, their actual contribution to business objectives such as quality improvement and cost reduction has rarely been assessed. This paper proposes using a simulation model of software testing to assess the cost effectiveness of test effort allocation strategies based on fault prediction results. The simulation model estimates the number of discoverable faults with respect to the given test resources, the resource allocation strategy, a set of modules to be tested, and the fault prediction results. In a case study applying fault prediction of a small system to acceptance testing in the telecommunication industry, results from our simulation model showed that the best strategy was to let the test effort be proportional to "the number of expected faults in a module x log(module size)." By using this strategy with our best fault prediction model, the test effort could be reduced by 25 percent while still detecting as many faults as were normally discovered in testing, although the company required about 6 percent of the test effort for metrics collection, data cleansing, and modeling. The simulation results also indicate that the lower bound of acceptable prediction accuracy is around 0.78 in terms of an effort-aware measure, (Norm(Popt)). The results indicate that reduction of the test effort can be achieved by fault prediction only if the appropriate test strategy is employed with high enough fault prediction accuracy. Based on these preliminary results, we expect further research to assess their general validity with larger systems. [ABSTRACT FROM PUBLISHER]

In this paper, we study the problem of computing quality fault-tolerant virtual backbone in homogeneous wireless network, which is defined as the k-connected m-dominating set problem in a unit disk graph. This problem is NP-hard, and thus many efforts have been made to find a constant factor approximation algorithm for it, but never succeeded so far with arbitrary k\geq 3 and m\geq 1 pair. We propose a new strategy for computing a smaller-size 3-connected m-dominating set in a unit disk graph with any m\geq 1. We show the approximation ratio of our algorithm is constant and its running time is polynomial. We also conduct a simulation to examine the average performance of our algorithm. Our result implies that while there exists a constant factor approximation algorithm for the k-connected m-dominating set problem with arbitrary k\leq 3 and m\geq 1 pair, the k-connected m-dominating set problem is still open with k>3. [ABSTRACT FROM AUTHOR]

In this paper, H.264/AVC primary and redundant slices interlaced multiple description video coding (PRSI-MDVC) is studied due to its high coding efficiency and ease of constructing multiple descriptions by interleaving primary and redundant slices, where the problem of optimal description generation in the rate-distortion sense is addressed. Optimal description generation requires minimization of end-to-end distortion consisting of both source coding distortion determined by quality of primary slices and channel distortion associated with redundant slice coding, subject to a rate constraint. The relevant existing works on the description generation mainly focus on the estimation of channel distortion to determine the amount of inserted redundancy (quality of redundant slices) but ignore the source distortion estimation for the quality of primary slices, thus a comprehensive end-to-end rate-distortion optimization is still unavailable. In this paper, we attack the minimization of the end-to-end distortion by fully exploring temporal coding dependency. Specifically, on one hand, a most recently developed source distortion temporal propagation model is employed to determine coding options of primary slices in the PRSI-MDVC. On the other hand, channel distortion estimation is mainly concerned with the mismatch error estimation when primary slices are lost. Unlike the existing channel distortion estimation approach under the asymptotic fine quantization assumption which is not valid in most practical cases (e.g., at low or medium coding rates), we develop a novel and more feasible estimation scheme, based on which coding parameters of the redundant slices can be better determined. Simulation results show the effectiveness of the proposed frame-level rate-distortion optimized description generation scheme compared with the relevant approaches. [ABSTRACT FROM PUBLISHER]

This paper introduces a new approach for video super resolution problem. To this end Compressive Sensing (CS) theory along with contourlet transform has been used. In CS framework the signal is assumed to be sparse in a transform domain. An approach has been suggested using this fact in which contourlet domain is used as the transform domain and a CS algorithm helps to find the high resolution frame. A post processing step is applied afterward to the estimated outputs to increase the quality. The post processing step consists of a deblurring term and a Bilateral Total Variation (BTV) filter for increasing the consistency. This method helps to relax the conditions on hardware and increase the quality of the video after capturing, in fact the quality of the video streams in consumer applications can be increased even the capturing device represents the scene in a low resolution format. Experimental results show significant improvement over existing super resolution methods in both objective and subjective quality. [ABSTRACT FROM PUBLISHER]

This paper presents a procedure for synthesizing high-quality grasps for objects that need to be held and manipulated in a specific way, characterized by a prespecified set of contact constraints to be satisfied. Due to the multimodal nature of typical grasp quality measures, approaches that resort to local optimization methods are likely to get trapped into local extrema on such a problem. An additional difficulty is that the set of feasible grasps is a highly dimensional manifold, implicitly defined by a system of nonlinear equations. The proposed procedure finds a way around these issues by focusing the exploration on a relevant subset of grasps of lower dimension and tracing this subset exhaustively using a higher-dimensional continuation technique. A detailed atlas of the subset is obtained as a result, on which the highest quality grasp, according to any desired criterion, or a combination of criteria, can be readily identified. Examples are included that illustrate the application of the method to a three-fingered planar hand and to the Schunk anthropomorphic hand grasping different objects, using several quality indices. [ABSTRACT FROM AUTHOR]

The response of a variety of Earth observation satellite sensors from multiple platforms, as well as different sensors on the same platform, were cross-compared over Dome C in Antarctica. A single unified methodology was employed to remove geometric, temporal, and atmospheric biases between different sensors with a range of spatial resolutions, bandwidths, and overpass times. The result assumes no “correct” baseline value, only relative responses. The resulting responses of the sensors, namely, AATSR, MERIS, and VEGETATION 2, are here presented and, where overlap occurs, compared with the results from other groups. In addition to applying the Quality Assurance for Earth Observation protocols for the quality assurance of environmental monitoring satellites, this paper discusses the intercalibration of several sensors used to establish the technical basis of the ESA GlobAlbedo project. [ABSTRACT FROM PUBLISHER]