Quality Assurance Capabilities Research Articles

Quality-Achieving Reliability Assessment of Rolling Bearing Based on Bootstrap Maximum Entropy Method and Similarity Method.

Rolling bearing reliability is often affected by the processing quality, however the life reliability or operating reliability do not involve the study of rolling bearing processing quality assessment. In order to avoid bearing failure caused by bearing processing quality, it is necessary to evaluate the reliability of the bearing quality assurance capability. The difficulty in reliable evaluation of bearing's quality assurance capability is how to quantify the uncertain relationships between the bearing quality and its influence factors, and then determine the weight of different influencing factors. Therefore, in this paper, a novel method for determining the weight of bearing quality-influencing factors based on bootstrap maximum entropy method and similarity method is proposed, and then the quality-achieving reliability model is established. The experimental results show that the proposed method can effectively quantify the relationship between the bearing quality and its influencing factors, and accurately assess the bearing quality assurance capability and bearing quality processing level under the condition of a small number of experimental bearings. Compared with other quality-achieving reliability method, the proposed method is more effective.

Photometric redshift calibration with self-organising maps

Accurate photometric redshift calibration is central to the robustness of all cosmology constraints from cosmic shear surveys. Analyses of the Kilo-Degree Survey (KiDS) re-weighted training samples from all overlapping spectroscopic surveys to provide a direct redshift calibration. Using self-organising maps we demonstrate that this spectroscopic compilation is sufficiently complete for KiDS, representing 99% of the effective 2D cosmic shear sample. We used the SOM to define a 100% represented “gold” cosmic shear sample, per tomographic bin. Using mock simulations of KiDS and the spectroscopic training set, we estimated the uncertainty on the SOM redshift calibration, and we find that photometric noise, sample variance, and spectroscopic selection effects (including redshift and magnitude incompleteness) induce a combined maximal scatter on the bias of the redshift distribution reconstruction (Δ⟨z⟩ = ⟨z⟩est − ⟨z⟩true) of σΔ⟨z⟩ ≤ 0.006 in all tomographic bins. Photometric noise and spectroscopic selection effects contribute equally to the observed scatter. We show that the SOM calibration is unbiased in the cases of noiseless photometry and perfectly representative spectroscopic datasets, as expected from theory. The inclusion of both photometric noise and spectroscopic selection effects in our mock data introduces a maximal bias of Δ⟨z⟩ = 0.013 ± 0.006, or Δ⟨z⟩ ≤ 0.025 at 97.% confidence, once quality flags have been applied to the SOM. The method presented here represents a significant improvement over the previously adopted direct redshift calibration implementation for KiDS, owing to its diagnostic and quality assurance capabilities. The implementation of this method in future cosmic shear studies will allow better diagnosis, examination, and mitigation of systematic biases in photometric redshift calibration.

Research on Quality Management of Supply Chain Based on Information Quality in the Context of Big Data

Quality management of supply chain refers to management of producing, forming and realizing of production quality, so to achieve the quality assurance of product quality in the supply chain environment. Therefore, the establishment of a complete and effective supply chain quality management system, to ensure that the supply chain has a sustained and stable quality assurance capabilities, so that the needs of customers and the market can be responded rapidly, and to provide better service to customers. With the arrival of the information age, the quality of data has become a key point in the quality management of supply chain, and the source of data problems is put forward, and the quality of data is considered in the whole supply chain quality management process. Six Sigma management system framework based on data quality is established.

Data analytics for continuous renal replacement therapy: historical limitations and recent technology advances.

Dialysis is a highly quantitative therapy involving large volumes of both clinical and technical data. While automated data collection has been implemented for chronic dialysis, this has not been done for acute kidney injury patients treated with continuous renal replacement therapy (CRRT). After a brief review of the fundamental aspects of electronic medical records (EMRs), a new tool designed to provide clinicians with individualized CRRT treatment data is analyzed, with emphasis on its quality assurance capabilities. The first platform addressing the problem of data collection and management with current CRRT machines (Sharesource system; Baxter Healthcare) is described. The system provides connectivity for the Prismaflex CRRT machine and enables both EMR connectivity and therapy analytics with 2 basic components: the connect module and the report module. The enormous amount of data in CRRT should be collected and analyzed to enable adequate clinical decisions. Current CRRT technology presents significant limitations with consequent lack of rigorous analysis of technical data and relevant feedback. From a quality assurance perspective, these limitations preclude any systematic assessment of prescription and delivery trends that may be adversely affecting clinical outcomes. A detailed assessment of current practice limitations is provided together with several possible ways to address such limitations by a new technical tool.

Key Points to Facilitate the Adoption of Computer-Based Assessments.

There are strong pedagogical arguments in favor of adopting computer-based assessment. The risks of technical failure can be managed and are offset by improvements in cost-effectiveness and quality assurance capability. Academic, administrative, and technical leads at an appropriately senior level within an institution need to be identified, so that they can act as effective advocates. All stakeholder groups need to be represented in undertaking a detailed appraisal of requirements and shortlisting software based on core functionality, summative assessment life cycle needs, external compatibility, security, and usability. Any software that is a candidate for adoption should be trialed under simulated summative conditions, with all stakeholders having a voice in agreeing the optimum solution. Transfer to a new system should be carefully planned and communicated, with a programme of training established to maximize the success of adoption.

An Assessment of the Quality-Achieving Reliability of Mechanical Products Based on Information-Poor Theory

Abstract Reliable evaluation of a product's quality assurance capability is difficult to quantify due to the intricacies of the quality assurance process and the uncertain relationships between the product quality and its influence factors. To address this problem, with the aid of information-poor theory, a new concept, quality-achieving reliability, is proposed, and a corresponding evaluation model is structured to calculate the probability of achieving product quality as a function of the influence factors. Using the decomposition and composition method, quality classifications of the product evaluation indicator and its influence factors are produced to extract the cumulative distribution of the product quality and its elements. Using the grey relational grade method, a weight analysis of the impacts of the influence factors on the product quality is performed to obtain the status composite values of the influence factors. Under the condition of poor information and relying on the status composite values based on the cumulative distribution, a quality-achieving reliability function is established to reflect the quality assurance capability and quality control level of the product and its elements. An experimental investigation of the vibration acceleration of tapered roller bearings demonstrates the application of the proposed model.

A Cloud Service Broker with Legal-Rule Compliance Checking and Quality Assurance Capabilities

Abstract The ICT industry, and specifically critical sectors such as healthcare, transportation, energy and government require as mandatory the compliance of the ICT systems and services with legislation and regulation, as well as with standards. In the era of cloud computing, and particularly in a public cloud scenario, this compliance management issue is exacerbated by the distributed nature of the system and by the limited control of the customer on the infrastructure/services. Also if the cloud industry is aware of this legislation/regulation compliance issue (e.g. the compliance program of Amazon, Google and Microsoft Azure), right now, there are nor reference architectures neither mechanisms capable to check and to assure, off-line and at run-time, that the compliance is guaranteed during the whole life cycle of a cloud service. Cloud service brokerage can play an important role in law/regulation compliance management of cloud services. In this paper we propose a broker-based solution for the management of law/regulation compliance. In the specific first we define a reference architecture for a legislation-aware cloud service broker, and second we propose an autonomic manager that integrate the MAPE-K control loop with the LegEx framework for the management of the legal compliance checking lifecycle.

BrachyView, A novel inbody imaging system for HDR prostate brachytherapy: Design and Monte Carlo feasibility study

High dose rate (HDR) brachytherapy is a form of radiation therapy for treating prostate cancer whereby a high activity radiation source is moved between predefined positions inside applicators inserted within the treatment volume. Accurate positioning of the source is essential in delivering the desired dose to the target area while avoiding radiation injury to the surrounding tissue. In this paper, HDR BrachyView, a novel inbody dosimetric imaging system for real time monitoring and verification of the radioactive seed position in HDR prostate brachytherapy treatment is introduced. The current prototype consists of a 15 × 60 mm(2) silicon pixel detector with a multipinhole tungsten collimator placed 6.5 mm above the detector. Seven identical pinholes allow full imaging coverage of the entire treatment volume. The combined pinhole and pixel sensor arrangement is geometrically designed to be able to resolve the three-dimensional location of the source. The probe may be rotated to keep the whole prostate within the transverse plane. The purpose of this paper is to demonstrate the efficacy of the design through computer simulation, and to estimate the accuracy in resolving the source position (in detector plane and in 3D space) as part of the feasibility study for the BrachyView project. Monte Carlo simulations were performed using the GEANT4 radiation transport model, with a (192)Ir source placed in different locations within a prostate phantom. A geometrically accurate model of the detector and collimator were constructed. Simulations were conducted with a single pinhole to evaluate the pinhole design and the signal to background ratio obtained. Second, a pair of adjacent pinholes were simulated to evaluate the error in calculated source location. Simulation results show that accurate determination of the true source position is easily obtainable within the typical one second source dwell time. The maximum error in the estimated projection position was found to be 0.95 mm in the imaging (detector) plane, resulting in a maximum source positioning estimation error of 1.48 mm. HDR BrachyView is a feasible design for real-time source tracking in HDR prostate brachytherapy. It is capable of resolving the source position within a subsecond dwell time. In combination with anatomical information obtained from transrectal ultrasound imaging, HDR BrachyView adds a significant quality assurance capability to HDR brachytherapy treatment systems.

SU-E-T-377: Evaluation and Implementation of An IMRT Quality Assurance Procedure to Include Patient-Specific Volumetric Dose Analysis

Purpose: he purpose of this study is to evaluate and implement a digital IMRT quality assurance (QA) procedure for patient-specific volumetric dose using commercially available products. Dose distributions generated from a treatment planning system (TPS) were delivered and analyzed with dose-volume-histogram (DVH) analysis software. Methods: The MapCheck2 device along with 3DVH (Sun Nuclear, Melbourne, FL) software was studied for IMRT QA capabilities. All manufacturer specifications were followed in order to properly set up the diode array device for accurate absolute dose measurements. Planar dose maps were generated by the Pinnacle3 TPS (Philips Medical Systems, Andover, MA) for field-by-field IMRT QA analysis. Also exported from patient plans were RT dose, RT plan, RT structure, and CT data DICOM files. Dose delivery was done using a step-and-shoot, en-face technique onto the MapCheck2 device. After measured-vs-calculated planar dose analysis for each beam, a planned-dose-perturbation (PDP™) file was generated. This PDP file allows the software to manipulate the TPS-calculated dose distributions to include actual measured dose differences from a phantom onto a patient CT-dataset. These dose perturbations are then able to be observed through differences of a TPS-calculated DVH and a measured-DVH within the 3DVH software. Simple tests were performed to assess MapCheck2 performance and 3DVH sensitivity to errors. Results: All planar dose measurements in this study have met the clinical tolerance of 3% absolute dose/3mm gamma analysis. For volumetric analysis, the 3D results comparing planned-vs-delivered matching doses (gamma criterion of 3%/3mm) were 99.3% and 98.2% for a rectum and prostate plan, respectively. Measurements with introduction of intentional errors produced reasonable results when analyzing dose to critical structures with DVHs. Conclusion: The implementation of a digital QA procedure will facilitate a more efficient workflow for physicists with the added benefit of a patient-specific volumetric dose analysis for physicians.

Reconstruction of high-resolution 3D dose from matrix measurements: error detection capability of the COMPASS correction kernel method

The COMPASS system (IBA Dosimetry) is a quality assurance (QA) tool which reconstructs 3D doses inside a phantom or a patient CT. The dose is predicted according to the RT plan with a correction derived from 2D measurements of a matrix detector. This correction method is necessary since a direct reconstruction of the fluence with a high resolution is not possible because of the limited resolution of the matrix used, but it comes with a blurring of the dose which creates inaccuracies in the dose reconstruction. This paper describes the method and verifies its capability to detect errors in the positioning of a MLC with 10 mm leaf width in a phantom geometry. Dose reconstruction was performed for MLC position errors of various sizes at various locations for both rectangular and intensity-modulated radiotherapy (IMRT) fields and compared to a reference dose. It was found that the accuracy with which an error in MLC position is detected depends on the location of the error relative to the detectors in the matrix. The reconstructed dose in an individual rectangular field for leaf positioning errors up to 5 mm was correct within 5% in 50% of the locations. At the remaining locations, the reconstruction of leaf position errors larger than 3 mm can show inaccuracies, even though these errors were detectable in the dose reconstruction. Errors larger than 9 mm created inaccuracies up to 17% in a small area close to the penumbra. The QA capability of the system was tested through gamma evaluation. Our results indicate that the mean gamma provided by the system is slightly increased and that the number of points above gamma 1 ensures error detection for QA purposes. Overall, the correction kernel method used by the COMPASS system is adequate to perform QA of IMRT treatment plans with a regular MLC, despite local inaccuracies in the dose reconstruction.

Characterization and clinical evaluation of a novel IMRT quality assurance system

Intensity‐modulated radiation therapy (IMRT) is a complex procedure that involves the delivery of complex intensity patterns from various gantry angles. Due to the complexity of the treatment plans, the standard care is to perform measurement‐based, patient‐specific quality assurance (QA). IMRT QA is traditionally done with film for relative dose in a plane and with an ion chamber for absolute dose. This is a laborious and time‐consuming process. In this work, we characterized, commissioned, and evaluated the QA capabilities of a novel commercial IMRT device, Delta4, (ScandiDos, Uppsala, Sweden). This device consists of diode matrices in two orthogonal planes inserted in a cylindrical acrylic phantom that is 22 cm in diameter. Although the system has detectors in only two planes, it provides a novel interpolation algorithm that is capable of estimating doses at points where no detectors are present. Each diode is sampled per beam pulse so that the dose distribution can be evaluated on segment‐by‐segment, beam‐by‐beam, or as a composite plan from a single set of measurements. The end user can calibrate the system to perform absolute dosimetry, eliminating the need for additional ion chamber measurements. The patient's IMRT plan is imported into the device over the hospital LAN and the results of the measurements can be displayed as gamma profiles, distance‐to‐agreement maps, dose difference maps, or the measured dose distribution can be superimposed on the patient's anatomy to display an as‐delivered plan. We evaluated the system's reproducibility, stability, pulse‐rate dependence, dose‐rate dependence, angular dependence, linearity of dose response, and energy response using carefully planned measurements. We also validated the system's interpolation algorithm by measuring a complex dose distribution from an IMRT treatment. Several simple and complex isodose distributions planned using a treatment planning system were delivered to the QA device; the planned and measured dose distributions were then compared and analyzed. In addition, the dose distributions measured by conventional IMRT QA, which uses an ion chamber and film, were compared. We found that the Delta4 device is accurate and reproducible and that its interpolation algorithm is valid. In addition, the supplied software and network interface allow a streamlined IMRT QA process.PACS number: 87.56Fc

Corporate Learning and Quality Control at the Bell System, 1877–1929

From 1877 to 1929 the Bell System extended its qualityassurance capabilities, a step that was critical to the company's ability to certify the reliability of its equipment and apparatus and to provide economical service. Learning in this context involved the gradual development of an organizational structure for coordinating and controlling quality-assurance activities at both the staff and line levels and between the corporate elements of the Bell System. Over the course of the initiative, innovative methods of analysis emerged that provided useful new insights into the manufacturing process. The company's adaptation of probability theory, for example, enabled it to launch a comprehensive inspection regime, which became known as “statistical quality control” (SQC). Based on this new approach, Bell succeeded in broadening its manufacturing knowledge, quantifying definitions of quality, reducing costs and risk, thus assuming the more reliable operation of its vast telephone network. Eventually this upgrading of learning led to the formation of a new profession of quality engineering, which found adherents across many industries in the United States and abroad.

SOFTWARE QUALITY ASSURANCE IN CASE TOOLS Creating an AI-Enhanced CASE Tool

Abstract Artificial intelligence (Al) techniques can be applied within the IS shop to improve quality assurance. This article describes an Al-assisted method for migrating software quality assurance capability to conventional CASE tools.

Air quality in Metropolitan Manila: Inferences from a questionable data set

Abstract Metropolitan Manila, Republic of the Philippines, is one of the more polluted cities in the world. It may be unique in that, to all appearances, the air pollutant loading is virtually all particulate. The Philippine government is now, with support from a number of international agencies, attempting to set priorities and control the most serious of its environmental problems. There have been numerous attempts to estimate the relative contributions of various sources of air pollutants, but the lack of emission factors applicable to the specific technologies used in Manial makes these suspect. Air monitoring data are available, but are seriously compromised by the lack of quality assurance capabilities and calibration facilities for the monitors. During years 1987–1989 several data sets were taken at stations in the area. The sampling/monitoring equipment consisted of the survivors from a larger number of devices bought a number of years earlier, and kept running by progressive cannibalization of less viable instruments to provide parts for the balance. Hence neither the accuracy nor the precision of the data were known. Accuracy could not, of course, be ascertained. However, a number of statistical techniques (some only marginally applicable in the strict statistical sense, since the data were almost certainly not normally distributed) showed the data to have about the expected dispersion, to have some interesting coherences, and to reveal that the airborne particles had, on average, a quite constant iron content. Almost certainly this indicated a significant soil source for particulate matter, not previously identified. On the whole, the data set was probably better than most visiting scientists had believed, and could be used for planning further studies, though not for setting control priorities.

Test Facilities for Radioactive Material Transport Packages (Oak Ridge National Laboratory, USA)

The Oak Ridge National Laboratory (ORNL) has extensive capabilities to test full-scale and model packages that have been designed to the testing requirements of the Code of Federal Regulations, Title 10, Part 71.73. These are the same teststhat are specified in the International Atomic Energy Agency (IAEA) ‘Regulations for the Safe Transport of Radioactive Material’, Safety Series No.6, 1985 edition as amended in 1990. This report provides information about the facilities, personnel qualifications, prior test experience, and quality assurance capabilities which are available to support package testing.

The development of the essential drugs program and implications for self-reliance in Tanzania

This report provides a background history of the Essential Drugs Program (EDP) in Tanzania. Because of a scarcity of drugs in the Ministry of Health (MOH) managed units a program to fill up the empty shelves was welcomed. Critical questions were not addressed about other important policy components. Success of the EDP has been measured in terms of a successful delivery of drugs without questioning the source and its reliability in the near future. Other program components have not been implemented successfully to insure the program's sustainability and self-reliance. There is a need to improve local production, quality assurance capability, inspection, intersectoral linkages and active local participation in shouldering the financial burden.