To Plan or to Simply React? An Experimental Study of Action Planning in a Game Environment

Many contemporary computer games, notably action and role‐playing games, represent an interesting class of navigation‐intensive dynamic real‐time simulations inhabited by autonomous intelligent virtual agents (IVAs). Although higher level reasoning of IVAs in these domains seems suited for action planning, planning is not widely adopted in existing games and similar applications. Moreover, statistically rigorous study measuring performance of planners in decision making in a game‐like domain is missing. Here, five classical planners were connected to the virtual environment of Unreal Development Kit along with a planner for delete‐free domains (only positive preconditions and positive effects). Performance of IVAs employing those planners and IVAs with reactive architecture was measured on a class of game‐inspired test environments of various sizes and under different levels of external interference. The analysis has shown that planning agents outperform reactive agents if (i) the size of the problem is small or if (b) the environment changes are either hostile to the agent or infrequent. In delete‐free domains, specialized approaches are inferior to classical planners because the lower expressivity of delete‐free domains results in lower plan quality. These results can help to determine when planning is advantageous in games and for IVAs control in other dynamic real‐time environments.     

Evaluating the effect of a lightweight formal technique in industry

We evaluate the effect of applying the commercial formal technique Analytical Software Design (ASD) to an industrial project. In ASD, interfaces and software designs are modelled using a formal tabular notation. The ASD tool set supports formal checks of these models, such as deadlock freedom and interface compliance. In addition, full code can be generated from design models. ASD has been applied at Philips Healthcare to develop parts of the software of interventional X-ray systems. We report about the experiences with the embedding of ASD into the development processes. The quality of the resulting code and the productivity has been analysed and compared to code developed with other techniques. We observe that the use of ASD leads to a strong reduction of the number of defects and an increase in productivity. The results are also compared to the literature about standards and related projects at other companies.     

Brain-inspired algorithms for retinal image analysis

Retinal image analysis is a challenging problem due to the precise quantification required and the huge numbers of images produced in screening programs. This paper describes a series of innovative brain-inspired algorithms for automated retinal image analysis, recently developed for the RetinaCheck project, a large-scale screening program for diabetic retinopathy and other retinal diseases in Northeast China. The paper discusses the theory of orientation scores, inspired by cortical multi-orientation pinwheel structures, and presents applications for automated quality assessment, optic nerve head detection, crossing-preserving enhancement and segmentation of retinal vasculature, arterio-venous ratio, fractal dimension, and vessel tortuosity and bifurcations. Many of these algorithms outperform state-of-the-art techniques. The methods are currently validated in collaborating hospitals, with a rich accompanying base of metadata, to phenotype and validate the quantitative algorithms for optimal classification power.     

Effect of job rotation on work demands, workload, and recovery of refuse truck drivers and collectors

Job rotation is often advocated to reduce workload, but its efficacy has seldom been investigated. The aim of this study is to compare the work demands, workload, and recovery among truck driving, refuse collecting, and rotating between these two jobs, between days and during the day. Three teams of 3 employees each participated in this study. Work demands were assessed by systematic observation of tasks and activities. Workload was quantified by means of heart rate, oxygen uptake, subjective ratings, and urinary excretion rates of catecholamines. Recovery was quantified by excretion rates of catecholamines after work. Job rotation between driving and collecting is an effective measure to reduce physical workload as compared with collecting only and to decrease mental workload as compared with driving only. However, job rotation resulted in increased physical workload as compared with driving only. Job rotation did not increase mental workload as compared with collecting only. No effects were seen on recovery. No differences were found between rotating between days and during the day. Actual or potential applications of this research include the recommendation that before job rotation is introduced, its efficacy be determined in terms of well-chosen workload measures because a reduction in work demands does not directly imply a reduction in workload. Therefore, job rotation might be less effective than expected.