Commentary on “Visualization in Operations Management Research”

This thoughtful review productively covers use of visualization in three operations management research issues: theory/model development, theory/model testing, and translation/conveyance. The authors’ admirable motivation is to promote use of visualization, but I believe (1) that a wider scope would provide a stronger foundation for their encouragement and (2) that a more positive attitude would increase the chances of their succeeding.

HULLFORM & HYDRODYNAMIC CONSIDERATIONS IN THE DESIGN OF THE UK FUTURE AIRCRAFT CARRIER (CVF)

The author is to be congratulated in producing a paper for the journal on an important aspect (hydrodynamics) of a design, which was taken to a considerable level of definition before not being proceeded with. The fact that we so rarely get visibility of the thinking and effort behind “abortive” designs – so very little was allowed to be preserved of the cancelled CVA01 of the 1960s – and that this can be compared to the separately evolved, subsequently fully design and, now in 2017, about to go into service QUEEN ELIZABETH (QEC) carrier, makes this a very worthwhile document for the Transactions. Not only can the various detailed conclusions on the hydrodynamically related design choices be read for their input to the BAE Systems alternative to the Thales design, that was finally developed into the QEC (see S Knight’s 2009 RINA Conference paper), the paper also provides general insights into the interaction of one specific topic (hydrodynamics) with wider design developments. This can be instructive to future designers of complex ships – not just aircraft carriers. It could be argued that despite the growing capabilities of CFD tools, that there still appears to be a need for substantial model testing of discrete elements of the hydrodynamic design, as described. Would the author like to comment as to whether he sees this dual need for CFD and physical model testing likely to continue whenever new designs “are just that little bit too different” and how one might judge the latter?

Unsteady force measurements on propeller model in cavitation tunnels

Object and purpose of research. This paper discusses longitudinal unsteady force dynamometer for cavitation tunnel tests. The purpose of the study is to improve metrological performance of the dynamometer and extend the scope of its application. Materials and methods. The study is based on metrological parameters of dynamometers and model test data available with KSRC Large Cavitation Tunnel (LCT). Main results. Development, manufacturing, certification and commissioning of longitudinal unsteady force dynamometer based on piezoceramic load cell with improved metrological performance making it applicable for model testing of not only propellers but also other types of marine propulsors. Conclusion. Dynamometer with piezoceramic load cell offers more accurate measurement of unsteady forces, wider band of measurement frequencies, as well as wider spectrum of possible applications and lower susceptibility to interference.

A multi-species co-occurrence index to avoid type II errors in null model testing

Community structure is determined by the interplay among different processes, including biotic interactions, abiotic filtering, and dispersal. Their effects can be detected by comparing observed patterns of co-occurrence between different species (e.g. C-score and the natural metric) to patterns generated by null models based on permutations of species-by-site matrices under constraints on row or column sums. These comparisons enable us to detect significant signals of species association or dissociation, from which the type of biotic interactions between species (e.g. facilitative or antagonistic) can be inferred. Commonly used patterns are based on the levels of co-occurrence between randomly paired species. The level of co-occurrence for three or more species is rarely considered, ignoring the potential existence of functional guilds or motifs composed of multiple species within the community. Null model tests that do not consider multi-species co-occurrence could therefore generate false negatives (Type II error) in detecting non-random forces at play that would only be apparent for such guilds. Here, we propose a multi-species co-occurrence index (hereafter, joint occupancy) that measures the number of sites jointly occupied by multiple species simultaneously, of which the pairwise metric of co-occurrence is a special case. Using this joint occupancy index along with standard permutation algorithms for null model testing, we illustrate nine archetypes of multi-species co-occurrence and explore how frequent they are in the seminal database of 289 species-by-site community matrices published by Atmar and Patterson in 1995. We show that null model testing using pairwise co-occurrence metrics could indeed lead to severe Type II errors in one specific archetype, accounting for 2.4% of the tested community matrices.

A Digital Test Chart for Visual Assessment of Color Appearance Scales

A digital color appearance test chart, akin to a ColorChecker® Chart for human perception, was developed and evaluated both perceptually and computationally. The chart allows an observer to adjust the appearance of a limited number of color patches to allow a quick evaluation of perceived brightness, colorfulness, lightness, saturation, and hue on a display. The resulting data can then be used to compared observed results with the predictions of various color appearance models. Analyses in this paper highlight some known shortcomings of CIELAB, CIECAM02, and CAM16. Differences between CIECAM02 and CAM16 are also highlighted. This paper does not provide new psychophysical data for model testing, it simply describes a technique to generate such data and a computational comparison of models.

Environmentally friendly private cities in Indonesia and Malaysia

This paper is a review of the model to investigate the effect of safety and security, financial benefit, social status, and lifestyle facilities on residential purchase and residential satisfaction. The future research will survey residents in private cities in Indonesia and Malaysia. For Indonesia, samples will be taken in South Tangerang, specifically in Bintaro Jaya, BSD City, and Summerecon. For Malaysia, samples will be taken among residents of private cities in Malaysia. The analysis will employ the use of structural equation model using SPSS and Amos software. The accepted hypotheses are expected be result of this study. Safety and security, financial benefit, social status, and lifestyle facilities determine the residential purchase and residential satisfaction. The originality of the research is the study investigate comparative study of the model testing in two countries, Indonesia and Malaysia.