Control of a Batch Processing Machine Serving Compatible Job Families

We consider the control of a single batch processing machine with random arrivals, random processing times, and compatible job families (jobs from different families may be processed together in the same batch, with the processing time distribution of the entire batch determined by the job family in the batch having the greatest expected processing time). The objective is to minimize the long-run average time that jobs spend in the system. We present properties possessed by the optimal policies and discuss the structure of these policies. We next develop a simple heuristic scheduling policy to control the machine. Simulation results are provided to demonstrate the effectiveness of our heuristic over a wide range of problem instances.     

A study of demographic embodiments of product recommendation agents in electronic commerce

Product Recommendation Agents (PRAs) and other web-based decision aids are deployed extensively to provide online shoppers with virtual advising services. While the design of PRA’s functional features has received a high degree of attention in academic studies, the social aspects of human–PRA interactions are comparatively less explored.This paper investigates the potential of enhancing users’ social experiences of interacting with an anthropomorphic PRA (i.e., an agent with human-like characteristics, such as facial expressions, body gestures, or speech output) by manipulating its demographic embodiments. The two demographic variables assessed are ethnicity and gender. As suggested by similarity-attraction theory and social identity theory, the results of our laboratory experiment reveal that PRAs that match the ethnicity, though not the gender, of their users are perceived as more sociable, more enjoyable, and more useful to interact with than the mismatched ones. More interestingly, the “matching-up” effects of ethnicity are more significant among female users than males. Implications for practitioners on how to use an anthropomorphic agent’s demographic characteristics to enhance users’ interaction experience are also discussed.     

An optimal image transform for threshold-based cloud detection using heteroscedastic discriminant analysis

We present a simple image transform that optimally combines four image channels into a greyscale image for threshold-based cloud detection. These image channels, namely blue, green, red and near infrared, are present on many low Earth-orbit resource satellites. Applying a single threshold to a greyscale image is a computationally efficient method suitable for onboard implementation. We used heteroscedastic discriminant analysis (HDA), which is a generalization of the popular dimension-reducing linear discriminant analysis, to transform the image. Comparative tests between HDA, existing transforms from the remote-sensing literature (the haze optimized and D transforms), as well as the single red and blue image channels were conducted. Although thin clouds remain challenging for global threshold-based techniques, the HDA transform consistently gave the best average segmentation errors across the test dataset. This dataset consisted of 32 1 megapixel Quickbird and Landsat images. HDA has not previously been applied to remote-sensing data.     

Designing intelligent systems to handle system failures: Enhancing explanatory power with less restrictive user interfaces and deep explanations

This research empirically investigates the design choices that can be made to facilitate problem solving when intelligent systems fail. One way is to provide deep explanations, which are explanations that justify system actions. Another way is to manipulate system restrictiveness of the user interface. An experiment was conducted to investigate the effectiveness of deep explanation support, as well as manipulations of system restrictiveness. Results suggest that the less restrictive system was more effective for problem‐solving situations where system failure occurred. In addition, deep explanations were found to be somewhat helpful in system understanding, and this, in turn, led to improved problem‐solving performance.     

High optical quality nanocrystalline diamond with reduced non-diamond contamination

It is important for optical applications of nanocrystalline diamond to achieve low optical absorption as well as optical scattering. We discuss the optical and photocurrent spectra measured by the transmittance and reflectance, photothermal deflection spectroscopy, laser calorimetry and dual beam photocurrent spectroscopy of low non-diamond content nanocrystalline diamond films grown by microwave plasma enhanced chemical vapor deposition on fused silica glass substrates.     

Contextualized access to knowledge: theoretical perspectives and a process-tracing study

This paper investigates the theoretical foundations and empirical evidence concerning contextualized access to task domain knowledge enabled by hypertext-style links. It examines several relevant theoretical perspectives, including theories of discourse comprehension, contextualized learning and the production paradox, and reports on an exploratory study in the knowledge-based systems (KBS) domain. Process-tracing data was collected using a 'thinking-aloud' procedure, and data analysis focused on some highly illustrative verbal protocols. Results indicate that contextualized access to domain knowledge can be critical for understanding KBS output, and that lack of it can cause comprehension difficulties. Contextualized access is highly effective for resolving comprehension difficulties arising from the users' lack of task domain knowledge and for reducing the motivational 'cost' of learning. We conclude that it has the potential for substantially increasing the effectiveness of information systems.     

Synthesis and characterization of cross‐linked poly(sodium acrylate)/sodium silicate hydrogels

Transparent and intumescent polymer‐silicate hydrogels were synthesized by free‐radical polymerization, in the presence of the redox initiators system (potassium persulphate/sodium thiosulphate) and cross‐linking monomer (N,N′‐methylenebisacrylamide). Hydrogels obtained in such a manner were rheologically tested and it was found that the same sample with a different sodium acrylate concentration polymerized faster when its content was lower. The spectroscopic and thermal analysis proved that the polymer combines with sodium silicate by hydrogen bonds and during thermal degradation only small polymer fragments and water molecules were released. NMR studies have shown that the content of water glass causes shorter relaxation times. Conducted fire tests showed that glass panes systems filled with the tested hydrogels meet the relevant construction standards and what is their big advantage, a thin 1 mm layer of polymer‐silicate gel is sufficient for this purpose. We believe that these results will contribute to the development of intumescent hydrogels with enhanced fire‐retardant properties. POLYM. ENG. SCI., 59:1279–1287 2019. © 2019 Society of Plastics Engineers