Neural Feedback Scheduling of Real-Time Control Tasks

Many embedded real-time control systems suffer from resource constraints and dynamic workload variations. Although optimal feedback scheduling schemes are in principle capable of maximizing the overall control performance of multitasking control systems, most of them induce excessively large computational overheads associated with the mathematical optimization routines involved and hence are not directly applicable to practical systems. To optimize the overall control performance while minimizing the overhead of feedback scheduling, this paper proposes an efficient feedback scheduling scheme based on feedforward neural networks. Using the optimal solutions obtained offline by mathematical optimization methods, a back-propagation (BP) neural network is designed to adapt online the sampling periods of concurrent control tasks with respect to changes in computing resource availability. Numerical simulation results show that the proposed scheme can reduce the computational overhead significantly while delivering almost the same overall control performance as compared to optimal feedback scheduling.Comment: To appear in International Journal of Innovative Computing, Information and Contro

Fuzzy Feedback Scheduling of Resource-Constrained Embedded Control Systems

The quality of control (QoC) of a resource-constrained embedded control system may be jeopardized in dynamic environments with variable workload. This gives rise to the increasing demand of co-design of control and scheduling. To deal with uncertainties in resource availability, a fuzzy feedback scheduling (FFS) scheme is proposed in this paper. Within the framework of feedback scheduling, the sampling periods of control loops are dynamically adjusted using the fuzzy control technique. The feedback scheduler provides QoC guarantees in dynamic environments through maintaining the CPU utilization at a desired level. The framework and design methodology of the proposed FFS scheme are described in detail. A simplified mobile robot target tracking system is investigated as a case study to demonstrate the effectiveness of the proposed FFS scheme. The scheme is independent of task execution times, robust to measurement noises, and easy to implement, while incurring only a small overhead.Comment: To appear in International Journal of Innovative Computing, Information and Contro

Stiffness identification of boundary conditions by using thin-layer element for parameterization

The stiffness of boundary conditions in mechanical structures is difficult to represent. A method is proposed to model the mechanical performance of the clamped boundary condition based on thin-layer element. Firstly, the contact surface of clamped boundary condition is parameterized by using isotropic thin-layer element to model the normal and tangential contact stiffness. Secondly, material parameter of thin-layer element is identified by using experimental modal data, parameter identification is transformed as an optimization problem. Experimental investigation is undertaken to verify the proposed method by employing an aluminum honeycomb panel, the numerical model of which is constructed by using the equivalent theory. Thin-layer elements with different properties are used to simulate the mechanical properties in different area of the boundary conditions, and the experimental modal data is adopted to identify the material parameters. Results show that the width to thickness ratio of the thin layer element has a great influence on the identification results

A Heuristic Neural Network Structure Relying on Fuzzy Logic for Images Scoring

Traditional deep learning methods are sub-optimal in classifying ambiguity features, which often arise in noisy and hard to predict categories, especially, to distinguish semantic scoring. Semantic scoring, depending on semantic logic to implement evaluation, inevitably contains fuzzy description and misses some concepts, for example, the ambiguous relationship between normal and probably normal always presents unclear boundaries (normal − more likely normal - probably normal). Thus, human error is common when annotating images. Differing from existing methods that focus on modifying kernel structure of neural networks, this study proposes a dominant fuzzy fully connected layer (FFCL) for Breast Imaging Reporting and Data System (BI-RADS) scoring and validates the universality of this proposed structure. This proposed model aims to develop complementary properties of scoring for semantic paradigms, while constructing fuzzy rules based on analyzing human thought patterns, and to particularly reduce the influence of semantic conglutination. Specifically, this semantic-sensitive defuzzier layer projects features occupied by relative categories into semantic space, and a fuzzy decoder modifies probabilities of the last output layer referring to the global trend. Moreover, the ambiguous semantic space between two relative categories shrinks during the learning phases, as the positive and negative growth trends of one category appearing among its relatives were considered. We first used the Euclidean Distance (ED) to zoom in the distance between the real scores and the predicted scores, and then employed two sample t test method to evidence the advantage of the FFCL architecture. Extensive experimental results performed on the CBIS-DDSM dataset show that our FFCL structure can achieve superior performances for both triple and multiclass classification in BI-RADS scoring, outperforming the state-of-the-art methods

Low Expression of DYRK2 (Dual Specificity Tyrosine Phosphorylation Regulated Kinase 2) Correlates with Poor Prognosis in Colorectal Cancer.

Dual-specificity tyrosine-phosphorylation-regulated kinase 2 (DYRK2) is a member of dual-specificity kinase family, which could phosphorylate both Ser/Thr and Tyr substrates. The role of DYRK2 in human cancer remains controversial. For example, overexpression of DYRK2 predicts a better survival in human non-small cell lung cancer. In contrast, amplification of DYRK2 gene occurs in esophageal/lung adenocarcinoma, implying the role of DYRK2 as a potential oncogene. However, its clinical role in colorectal cancer (CRC) has not been explored. In this study, we analyzed the expression of DYRK2 from Oncomine database and found that DYRK2 level is lower in primary or metastatic CRC compared to adjacent normal colon tissue or non-metastatic CRC, respectively, in 6 colorectal carcinoma data sets. The correlation between DYRK2 expression and clinical outcome in 181 CRC patients was also investigated by real-time PCR and IHC. DYRK2 expression was significantly down-regulated in colorectal cancer tissues compared with adjacent non-tumorous tissues. Functional studies confirmed that DYRK2 inhibited cell invasion and migration in both HCT116 and SW480 cells and functioned as a tumor suppressor in CRC cells. Furthermore, the lower DYRK2 levels were correlated with tumor sites (P = 0.023), advanced clinical stages (P = 0.006) and shorter survival in the advanced clinical stages. Univariate and multivariate analyses indicated that DYRK2 expression was an independent prognostic factor (P < 0.001). Taking all, we concluded that DYRK2 a novel prognostic biomarker of human colorectal cancer

Carabus (Coleoptera: Carabidae) assemblages of native forests and non-native plantations in Northern China

The effects of non-native plantation established after clear-cutting were studied in Dongling Mountain region, Northern China. Pitfall catches of Carabus beetles from a non-native larch plantation were compared with those from two native forests, an oak forest and a mixed broad-leaved forest. More individuals were captured from the mixed broad-leaved forest and the larch plantation than from the oak forest. For the threemost abundant species in this area, C. crassesculptus peaked in abundance in the mixed broad-leaved forest; C. manifestus peaked in the larch plantation, and C. sculptipennis in the oak forest. Measured by PcoAusing Bray-Curtis index of dissimilarity, species composition of the larch plantation was different from the two native forests, but overlapped remarkably with them. All the three abundant species showed a similar positive relationship between local distribution and abundance. Captures of abundant species were clumped within the forest, but the extent of aggregation among forests was different. Monthly catches of total Carabus, and C. crassesculptus alone, peaked in June–August in all the three forests, but C. manifestus peaked in June and again in August. Our results suggest that the planting of non-native larch does not have a detrimental effect on Carabus assemblages in general, but it changes the spatial distribution and abundance compared to the native forests

[3,3′-Dihy­droxy-3,3′-bis­(pyridin-3-yl-κN)-1,1′-(pyridine-2,6-di­yl)dipropan-1-one](nitrato-κ2 O,O′)silver(I)

In the title compound, a new macrocyclic metal complex, [Ag(NO3)(C21H15N3O4)], all non-H atoms are in a close-to-planar geometry (except for the nitrate anion), with a maximum out-of-plane deviation of 0.327 (6) Å for a pyridine C atom. The dihedral angle between the least-squares plane through the [3,3′-dihy­droxy-3,3′-bis­(pyridin-3-yl)-1,1′-(pyridine-2,6-di­yl)dipropan-1-one]silver(I) fragment and the nitrate anion is 31.29 (13)°. The mol­ecular structure is stabilized by several inter- and intra­molecular O—H⋯O and C—H⋯O hydrogen bonds. The AgI atom is coordinated by two pyridine N atoms and two O atoms of the nitrate anion in a geometry intermediate between tetrahedral and square-planar

Habitat associations and seasonal activity of carabid beetles (Coleoptera: Carabidae) in Dongling Mountain, North China

Habitat distribution and seasonal occurrence of carabid beetles were determined using pitfall traps in 1999 and 2000 in the temperate forest zone of the Dongling Mountain, North China. Eight sites differing in vegetation and moisture were selected so as to represent four habitat types. Carabid assemblages of the six forested habitats (lowland, upland and coppice) weremore similar to each other than to the two shrub assemblages. Lowland forest had the highest species richness, and coppice forest had the highest diversity (H’) and equitability (J). Of the 41 species caught, the 18 most abundant species were divided into four distribution types: habitat generalists, forest generalists, forest specialists, and shrub (or coppice) specialists. Mean catches of all beetles showed clear peaks from May to August in nearly all habitats. The catches of the six most abundant species were more or less positively correlated during the two study years, suggesting their similar habitat preferences