An Adaptive Reference Vector Adjustment Strategy and Improved Angle-Penalized Value Method for RVEA

Decomposition-based evolutionary multiobjective algorithms (MOEAs) divide a multiobjective problem into several subproblems by using a set of predefined uniformly distributed reference vectors and can achieve good overall performance especially in maintaining population diversity. However, they encounter huge difficulties in addressing problems with irregular Pareto fronts (PFs) since many reference vectors do not work during the searching process. To cope with this problem, this paper aims to improve an existing decomposition-based algorithm called reference vector-guided evolutionary algorithm (RVEA) by designing an adaptive reference vector adjustment strategy. By adding the strategy, the predefined reference vectors will be adjusted according to the distribution of promising solutions with good overall performance and the subspaces in which the PF lies may be further divided to contribute more to the searching process. Besides, the selection pressure with respect to convergence performance posed by RVEA is mainly from the length of normalized objective vectors and the metric is poor in evaluating the convergence performance of a solution with the increase of objective size. Motivated by that, an improved angle-penalized distance (APD) method is developed to better distinguish solutions with sound convergence performance in each subspace. To investigate the performance of the proposed algorithm, extensive experiments are conducted to compare it with 5 state-of-the-art decomposition-based algorithms on 3-, 5-, 8-, and 10-objective MaF1–MaF9. The results demonstrate that the proposed algorithm obtains the best overall performance.

Evolution of the Mesenteric Mass in Small Intestinal Neuroendocrine Tumours

Background: A metastatic mesenteric mass is a hallmark of small intestinal neuroendocrine tumours (SI-NETs). However, little is known on its development over time. Therefore, we conducted a study to assess the evolution of a SI-NET-associated mesenteric mass over time. Methods: Retrospectively, 530 patients with proven SI-NET were included. The presence and growth of a mesenteric mass was assessed using RECIST 1.1 criteria on every consecutive CT-scan until the end of follow-up or resection. Results: At baseline, a mesenteric mass was present in 64% of the patients, of whom 13.5% showed growth of the mesenteric mass with a median time to growth of 40 months. Male gender was the only independent predictor of growth (OR 2.67). Of the patients without a mesenteric mass at the first evaluation, 2.6% developed a pathological mesenteric mass. Treatment with peptide receptor radionuclide therapy (PRRT; N = 132) resulted in an objective size reduction of the mesenteric mass in 3.8%. Conclusion: The metastatic mesenteric mass in SI-NETs has a static behavior over time. Therefore, site-specific growth behavior should be taken into account when selecting target lesions and assessing disease progression and therapeutic response. PRRT appears not to be effective for size reduction of the mesenteric mass.

Imagery

Most philosophers prior to the twentieth century thought of mental images as inner pictures, along lines suggested by introspection. But there are obvious differences between mental images and pictures. The former have no objective size or shape, for example. These differences have led some philosophers to argue that mental images are more like linguistic descriptions. The descriptional view of images is also taken by some cognitive psychologists. Other psychologists maintain that the pictorial conception of images provides the best explanation for the results of a number of intriguing experiments on imagery.

Perceptions of Racial Group Size in a Minority-majority Area

Americans overestimate the size of minority groups and underestimate the size of the majority. Research on perceived racial group size, however, has focused on areas where non-Hispanic whites are dominant and has neglected to examine the impact of group conflict attitudes other than perceived threats. This study examines perceptions of group size in Harris County, Texas, in 2007, which became a minority-majority area by 2006. It also examines whether perceived racial discrimination influences perceived group size. Analyses demonstrate that people underestimate the size of the largest group, which in this case is the local Hispanic population. The sizes of the black and Asian populations, by contrast, are overestimated while estimates of the white population are accurate. Race and perceived discrimination play important roles in shaping perceptions of group size. Perceptions of group size are also based on the objective size of these groups, but are unrelated to recent changes in group size.

Analysis and Optimization on the Front Supporter of Concrete Mixer Truck

The finite element software ANSYS is applied to optimize the front supporter of the concrete mixer truck. The main goal of the optimization is to reduce the quality. The statics analysis and the modal analysis of the front supporter are performed in the most dangerous work condition. The results of the two analyses are combined to explore improvement methods. Then, the topology optimization is performed to propose and establish the final shape and parameterization model. Finally, the multi-objective size optimization is performed to obtain the best optimization result. The maximum equivalent stress has reduced by 7.5%, and the quality has reduced by 13%.

Length Judgments of Body Parts

Independent groups of subjects judged the size of four body-parts and four nonbody stimuli under two size-instruction conditions. The shapes of the nonbody stimuli approximated the shapes of the body-parts. For both apparent and objective size instructions, the pattern of errors of body-part judgments confirmed the findings of Shontz (1969); judgmental errors of head-width and forearm-length were significantly greater than judgmental errors of hand-length and foot-length. Although not significant statistically, a similar pattern of errors was obtained for nonbody size judgments.