Quality control of sensor network data

A wireless sensor network (WSN) is a group of sensors that are geographically distributed and interconnected by wireless networks. Sensors gather information about the state of physical world. Then, after processing forward them to the main destination. To be able to provide this service, there are many aspects of communication techniques that need to be explored. Supporting quality of service (QoS) will be of critical importance for pervasive WSNs that serve as the network infrastructure of diverse applications. To illustrate new research and development interests in this field, this paper examines and discusses the requirements, critical challenges, and open research issues on QoS management in WSNs. A brief overview of recent progress is given.

A data quality control program for computer-assisted personal interviews

Researchers strive to optimize data quality in order to ensure that study findings are valid and reliable. In this paper, we describe a data quality control program designed to maximize quality of survey data collected using computer-assisted personal interviews. The quality control program comprised three phases: (1) software development, (2) an interviewer quality control protocol, and (3) a data cleaning and processing protocol. To illustrate the value of the program, we assess its use in the Translating Research in Elder Care Study. We utilize data collected annually for two years from computer-assisted personal interviews with 3004 healthcare aides. Data quality was assessed using both survey and process data. Missing data and data errors were minimal. Mean and median values and standard deviations were within acceptable limits. Process data indicated that in only 3.4% and 4.0% of cases was the interviewer unable to conduct interviews in accordance with the details of the program. Interviewers’ perceptions of interview quality also significantly improved between Years 1 and 2. While this data quality control program was demanding in terms of time and resources, we found that the benefits clearly outweighed the effort required to achieve high-quality data.

Quality control mechanisms regulating the copper-transporting ATPases ATP7A and ATP7B

This project provides compelling evidence that the clusterin, COMMD1 and ApoE proteins function in the quality control of the essential copper-transport proteins ATP7A and ATP7B. This knowledge is significant because variations in the clusterin, COMMD1 or ApoE genes may explain the variability of patient symptoms in the copper-transport disorders, Menkes and Wilson diseases.

A review of 16 years of quality control parameters at a mass-rearing facility producing Queensland fruit fly, Bactrocera tryoni

From 1996 to 2012, the mass-rearing facility at Camden (NSW, Australia) has been producing Queensland fruit flies, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae). During this time, the facility has regularly recorded fly quality parameters, creating a unique data set that provides an invaluable opportunity to evaluate the interrelationships among standard quality control (QC) parameters and test for redundant QC variables. Here, we conducted an exploratory data analysis to reveal relationships among the QC parameters. We found that pupal weight, adult lifespan, and longevity under nutritional stress (i.e., survival duration without food or water) had distinct monthly trends, suggesting that these QC parameters are sensitive to seasonal conditions. Furthermore, emergence percentage, flight ability, and adult lifespan were adversely affected by the dyeing/handling/irradiation process associated with sterile insect releases. Using a multivariate approach and controlling for monthly and yearly patterns, we showed that pupal weight and egg hatch are consistently negatively related and that percentage male and emergence rates are consistently negatively related. These results suggest that these correlation pairs measure similar quality information and hence one QC variable from each pair could be dropped. Flight ability was not strongly correlated with any of the QC variables, suggesting that this QC variable remains a useful QC metric. Finally, the longevity under nutritional stress QC appears to be fairly insensitive to QCs and we suggest that it should be replaced by the standard mortality under stress test.

Evaluating irradiation dose for sterility induction and quality control of mass-produced fruit fly Bactrocera tryoni (Diptera : Tephritidae)

The sterile insect technique has been routinely used to eradicate fruit fly Bactrocera tryoni (Froggatt) incursions. This study considers whether fly quality in a mass-rearing facility can be improved by reducing irradiation doses, without sacrificing reproductive sterility. Pupae were exposed to one of five target irradiation dose ranges: 0, 40-45, 50-55, 60-65, and 70-75 Gy. Pupae were then assessed using routine quality control measures: flight ability, sex ratio, longevity under nutritional stress, emergence, and reproductive sterility. Irradiation did not have a significant effect on flight ability or sex ratio tests. Longevity under nutritional stress was significantly increased at 70-75 Gy, but no other doses differed from 0 Gy. Emergence was slightly reduced in the 50-55, 60-65, and 70-75 Gy treatments, but 40-45 Gy treatments did not differ from 0 Gy, though confounding temporal factors complicate interpretation. Reproductive sterility remained acceptable (> 99.5%) for all doses--40-45 Gy (99.78%), 50-55 Gy (100%), 60-65 Gy (100%), and 70-75 Gy (99.99%). We recommend that B. tryoni used in sterile insect technique releases be irradiated at a target dose of 50-55 Gy, providing improved quality and undiminished sterility in comparison with the current 70-75 Gy standard while also providing a substantial buffer against risk of under dosing.

A question of continuing control -balancing building quality of housing and building codes

The Building Code of Australia seeks to establish “nationally consistent, minimum necessary standards of relevant, health, safety (including structural safety and safety from fire), amenity and sustainability objectives efficiently”. These goals are laudable – but where are the goals of quality and maintenance, which are also an essential part of achieving adequate and continuing health and safety for the built environment?

Defects such as dampness, settlement and cracking, staining, wood rot, termite damage, rusting, and roof leakage are common enough to suggest that there are still issues with building quality in housing. They are caused by a combination of initial poor workmanship and poor quality materials and latterly by poorly executed or inadequate maintenance.

Local architecture, developed over many years of trial and error, produce buildings linked to their climate and local materials (think of the typical “Queenslander” house). Today’s architecture imports technologies and materials from many differing countries and climates – that are not necessarily suitable for the location, nor is there necessarily the same quality control over the material quality and production. Inappropriate use and inadequate understanding of new materials and techniques can lead to the generation of further defects.

Whilst the building code contains provisions for initial-build material quality and workmanship, there is no continuing control over a house over its life span. Reliance is placed on advertising the need, for example, to employ qualified tradespeople; replace batteries in smoke detectors; and other good advice to help maintain housing to a minimum standard. Is this sufficient?

Mechanisms to make the transfer of knowledge to those who need to use it – be it the workforce or the houseowner – need to be improved. Should the building code be more visual and accessible in it’s content? Should the building code include provisions for maintenance? Should the building code require every house to have a “users manual” – much like a car? An extensive review of literature identifies the scale of the problem of poor quality housing and highlights some suggested causes – inadequate knowledge of the BCA by general housebuilders being one. However little work has been done to investigate what could be done to improve the situation. This work suggests that improvements to knowledge transfer would improve the quality of housing and a model of the knowledge transfer process is proposed, identifying those areas where the knowledge flows need to occur that would impact both the builders and users of housing.

Estimating quality costs in an automotive stamping plant through the use of simulation

The pressures of modern manufacturing require that the quality-cost benefits are determined when evaluating new procedures or alternative operating policies. Traditionally, cost reports and other quality metrics have been used for this purpose. However, the interactions between the main quality cost drivers cannot be understood at the superficial level and the effect that a new process or an alternative operating policy may have on quality costs is difficult to determine. An alternative to the traditional costing methods is simulation. The current work uses simulation to evaluate quality costs in an automotive stamping plant where the quality control is determined by operator inspection of their own work. Self-inspection quality control provides instantaneous feedback of quality problems, allowing for quick rectification. However, the difficult nature of surface finish inspection of automotive panels can create inspection and control errors. A simulation model was developed to investigate the cost effects of inspection and control errors and it was found that inspection error had a significant effect in increasing total quality cost, with the magnitude of this increase dependent on the level of control. Further, the simulation found that the lowest cost quality control policy was that which allowed a number of defective panels to accumulate before resetting the press-line.

The Sustainability and Evolution of Quality Improvement Programmes-an Australian Case Study

This paper presents a case study on the implementation of quality management programmes and initiatives in one manufacturing company in Australia, which has lasted for more than two decades. Using data collected through in-depth interviews, the case study describes how the company progressed from an earlier initiative based on quality control to the present initiatives that emphasize customer focus, product development, and innovation. Several important insights are drawn from the case study, including the importance of aligning the quality programmes or initiatives with a clear strategic focus. In addition, the commitment and leadership of senior management of the company has been demonstrated, particularly in the provision of resources and facilities to support the TQM programme, and also shown is how the company has been successful in maintaining its long-term commitment to quality management, which has led to an accumulation of various knowledge and competencies, which function as a valuable resource to sustain its business performance.

Building registration: training and housing quality

The lack of attention to quality control by house builders has been a contentious issue for more than three decades. In an attempt to improve the quality of housing, various mechanisms have been adopted and discarded by industry-based organizations and government legislation. Now that registration of builders has been achieved (since 1995) the regulating authority, the Building Commission have placed the maintenance of standards from registered builders at the forefront of their priorities. The provision of suitable training and continuing professional development programs is likely to receive greater attention over the next few years. However, a key factor that is often overlooked in the debate on quality of house construction is the use of subcontract labour by both, registered builders and owner builders. The repetitive nature of some activities ensures that tacit knowledge within the subcontract system becomes an integral part of house construction. Research by the authors into defects in housing has provided some interesting analyses from the statistic collected. This paper analyses the incidence of defects over a number of years in a range of functional elements within the house envelope and presents the results. Particular attention is paid to the incidence of defects where the licensed trades are involved compared to the non-licensed trades and elements. This work suggests where housing defects are likely to occur and the authors suggest that appropriate educational resources may be directed to areas where it will be most effective and beneficial. The authors propose a more integrated and inclusive approach.