A dynamically weighted discrete combination model for all releases of a software system

About 50% of the total cost of developing software is the cost of its testing and debugging. Software Reliability Growth models—which play an important role in planning and managing testing activity—are found to be appropriate in determining when the error levels are low enough to stop debugging. Although many Software Reliability Growth Models (SRGMS) have been proposed as continuous time models to plan and execute testing, there is a need to evolve discrete models to cater to discrete data. SRGMS have evolved over the years from simple to flexible models. This paper proposes the combination of two simple fault-based models to create a dynamically weighted model which describes both concave and S-shaped growth of mean value functions, occurring either in the whole project or in parts thereof. Most importantly, this combination model can be successfully deployed without modification for testing all the releases of a software product. On validation with a number of discrete datasets and releases, this model is found to provide satisfactory goodness of fit. In addition to being adequate for past failure data, predictive validity measures have confirmed that the proposed model will be equally adequate for future data also.     

A Method for Predicting Long-Term Municipal Water Demands Under Climate Change

Water Resources Management - The accurate forecast of water demand is challenging for water utilities, specifically when considering the implications of climate change. As such, this is the first...     

Ultrasonic thickness measuring in-pipe robot for real-time non-destructive evaluation of polymeric spray linings in drinking water pipe infrastructure

Drinking water pipelines are mainly underground and exposed to corrosion. Polymeric spray liners are used as an economical renewal method to mitigate the consequences of internal corrosion of pipelines and prolong their useful service life by many water utilities around the globe. The quality assurance of such applications is currently limited to closed-circuit television (CCTV), which only provides visual information. As part of the Australian government-funded, thirty-four partner multi-million dollar project (CRC-P: Smart Linings for Pipes and Infrastructure project), this work focuses on measuring the post-application thickness of spray liners in pipes. In this article, we report the innovative development of in-pipe robotic sensing suite that leverages ultrasonic sensing to continuously inspect the thickness of the spray linings through non-destructive measurements. The ultrasonic sensor was calibrated by fabricating laboratory test sample made from polymeric spray linings. Continuous uninterrupted coupling was achieved through a custom designed mechanism which was proven to be reliable through field deployments. Extensive lab tests were conducted to validate the sensor measurements with the benchmark measurements producing results with sub-millimeter accuracy. Following lab validations, field trials in buried pipe assets of Sydney Water were conducted for pipe lengths over 35 $m$, and the field test results show the robotic system is capable of reliably providing accurate spray liner thickness along the pipeline in real-time through non-destructive evaluation.     

Morphology control and phase transition of hexagonal sodium niobate particles

Hexagonal NaNbO₃ particles with an ilmenite structure and plate-like morphology were synthesized by a hydrothermal method. The morphological evolution of the solid products with the increasing mineralizer concentration was monitored via SEM during the hydrothermal reaction. By carefully controlling the mineralizer concentration, particles with a diameter of 10–60 µm and a thickness of 1–10 µm were obtained. The particles were transformed from the ilmenite structure into the perovskite structure during the thermal treatment at 600 °C. Their plate-like morphology was maintained with some cracking on the surface. The surface orientation of the perovskite particles was micro- and macroscopically characterized by EBSD and XRD analysis, respectively. The results indicate that thinner particles tend to be more oriented in the (00 l) crystal planes.     

Query based relevant music genre retrieval using adaptive artificial neural network for multimedia applications

Multimedia Tools and Applications - In the case of digital music industry, current major internet stores contain millions of tracks, which complicate search, retrieval and discovery of music...     

Decentralized PID controller for TITO systems using characteristic ratio assignment with an experimental application

This paper presents a decentralized PID controller design method for two input two output (TITO) systems with time delay using characteristic ratio assignment (CRA) method. The ability of CRA method to design controller for desired transient response has been explored for TITO systems. The design methodology uses an ideal decoupler to reduce the interaction. Each decoupled subsystem is reduced to first order plus dead time (FOPDT) model to design independent diagonal controllers. Based on specified overshoot and settling time, the controller parameters are computed using CRA method. To verify performance of the proposed controller, two benchmark simulation examples are presented. To demonstrate applicability of the proposed controller, experimentation is performed on real life interacting coupled tank level system.     

Blind method for rescaling detection and rescale factor estimation in digital images using periodic properties of interpolation

Availability of the powerful image editing softwares and advancement in digital cameras has given rise to large amount of manipulated images without any traces of tampering, generating a great demand for automatic forgery detection algorithms in order to determine its authenticity. When altering an image like copy–paste or splicing to conceal traces of tampering, it is often necessary to resize the pasted portion of the image. The resampling operation may highly likely disturb the underlying inconsistency of the pasted portion that can be used to detect the forgery. In this paper, an algorithm is presented that blindly detects global rescaling operation and estimate the rescaling factor based on the autocovariance sequence of zero-crossings of second difference of the tampered image. Experimental results using UCID and USC-SIPI database show the validity of the algorithm under different interpolation schemes. The technique is robust and successfully detects rescaling operation for images that have been subjected to various forms of attacks like JPEG compression and arbitrary cropping. As expected, some degradation in detection accuracy is observed as the JPEG quality factor decreased.     

Stabilizing p-Dithiobenzyl Urethane Linkers without Rate-Limiting Self-Immolation for Traceless Drug Release

Exploiting the redox sensitivity of disulfide bonds is a prevalent strategy in targeted prodrug designs. In contrast to aliphatic disulfides, p-thiobenzyl-based disulfides have rarely been used for prodrug designs, given their intrinsic instability caused by the low pK_a of aromatic thiols. Here, we examined the interplay between steric hindrance and the low-pK_a effect on thiol–disulfide exchange reactions and uncovered a new thiol–disulfide exchange process for the self-immolation of p-thiobenzyl-based disulfides. We observed a central leaving group shifting effect in the α,α-dimethyl-substituted p-dithiobenzyl urethane linkers (DMTB linkers), which leads to increased disulfide stability by more than two orders of magnitude, an extent that is significantly greater than that observed with typical aliphatic disulfides. In particular, the DMTB linkers display not only high stability, but also rapid self-immolation kinetics due to the low pK_a of the aromatic thiol, which can be used as a general and robust linkage between targeting reagents and cytotoxic drugs for targeted prodrug designs. The unique and promising stability characteristics of the present DMTB linker will likely inspire the development of novel targeted prodrugs to achieve traceless release of drugs into cells.     

Iterative-learning error compensation for autonomous parking of mobile manipulator in harsh industrial environment

In wide-area and multi-sites manufacturing scenarios, the mobile manipulator suffers from inadequate autonomous parking performance due to the harsh industrial environment. Instead of struggling to model various errors or calibrate multiple sensors, this paper resolves the above challenge by proposing an iterative-learning error compensation scheme that consists of offline pre-regulation and online compensation, which can improve the compensation efficiency and accommodate the error fluctuations caused by environmental fluctuations. Integrating an improved Monte-Carlo localization and eye-in-hand vision technique, an effective measurement system is firstly developed to accurately obtain the parking data without requiring superfluous facilities or cumbersome measurement. Then, after removing the data outliers utilizing the Grubbs test, offline pre-regulation is achieved to give a suitable initial value and increase the compensation convergence. To reduce the time-varying systematic errors and parking error fluctuations, online compensation is presented by offering an efficacious estimation of environmental fluctuations using fuzzy logic rules and providing an adaptive iterative-learning law. Finally, the feasibility and effectiveness of the presented compensation method are validated by extensive experiments implemented on a self-developed mobile manipulator.     

Tabletop integral imaging 3D display system based on annular point light source

When the viewers sitting around the table observe 3D images, the viewing direction is generally oblique and the viewpoints should be distributed as annular. In this paper, a tabletop integral imaging (II) three-dimensional (3D) display system based on annular point light sources is demonstrated, which can present 3D images to multiple viewers in a standard annular viewing area with oblique viewing direction. The proposed system consists of annular point light sources, a Fresnel lens, a lens array, a two-dimensional (2D) display panel, and a diffuser screen. Each point light source illuminates the Fresnel lens to form parallel light and then illuminates the lens array and the display panel. A viewing sub-area is generated at the position of the diffuser screen, in which the 3D images can be viewed. Multiple viewing sub-areas are created in a way of time-division multiplexing to form a 360° annular viewing area. Compared with the previous tabletop 3D display, the viewing area can be concentrated at an oblique angle near the tabletop. The experimental results demonstrate the feasibility of the tabletop II 3D display system.