Synchronization in Networks of Identical Systems via Pinning: Application to Distributed Secondary Control of Microgrids

Motivated by the need for fast synchronized operation of power microgrids, we analyze the problem of single and multiple pinning in networked systems. We derive lower and upper bounds on the algebraic connectivity of the network with respect to the reference signal. These bounds are utilized to devise a suboptimal algorithm with polynomial complexity to find a suitable set of nodes to pin the network effectively and efficiently. The results are applied to secondary voltage pinning control design for a microgrid in islanded operation mode. Comparisons with existing single and multiple pinning strategies clearly demonstrates the efficacy of the obtained results.Comment: 11 pages, 9 figures, submitted to Transactions on Control Systems Technolog

Residues and dissipation kinetics of two imidacloprid nanoformulations on bean (Phaseolus vulgaris L.) under field conditions

The current study investigates the dissipation kinetics of two imidacloprid (IMI) nanoformulations (entitled: Nano-IMI and Nano-IMI/TiO2) on common bean (Phaseolus vulgaris) seeds under field conditions and compares them with 35% Suspension Concentrate (SC) commercial formulation. To do so, it sprays P. vulgaris plants at 30 and 60 g/ha within green bean stage, sampling them during the 14-day period after the treatment. Following extraction and quantification of IMI residues, dissipation data have been fitted to simple-first order kinetic model (SFOK) and to first-order double-exponential decay (FODED) models, with 50% and 90% dissipation times (DT50 and DT90, respectively) assessed along the pre-harvest interval (PHI). With the exception of Nano-IMI at 60 g/ha, other decline curves are best fitted to the FODED model. In general, dissipation is faster for Nano-IMI (at 30 g/ha: DT50 = 1.09 days, DT90 = 4.30 days, PHI = 1.23 days; at 60 g/ha: DT50 = 1.29 days, DT90 = 4.29 days, PHI = 2.95 days) and Nano-IMI/TiO2 (at 30 g/ha: DT50 = 1.15 days, DT90 = 4.40 days, PHI = 1.08 days; at 60 g/ha: DT50 = 0.86 days, DT90 = 4.92 days, PHI = 3.02 days), compared to 35% SC (at 30 g/ha: DT50 = 1.58, DT90 = 6.45, PHI = 1.93; at 60 g/ha: DT50 = 1.58 days, DT90 = 14.50 days, PHI = 5.37 days). These results suggest the suitability of Nano-IMI and Nano-IMI/TiO2 application at both rates in terms of their residues on P. vulgaris seeds

Beyond the Hype: Assessing the Performance, Trustworthiness, and Clinical Suitability of GPT3.5

The use of large language models (LLMs) in healthcare is gaining popularity, but their practicality and safety in clinical settings have not been thoroughly assessed. In high-stakes environments like medical settings, trust and safety are critical issues for LLMs. To address these concerns, we present an approach to evaluate the performance and trustworthiness of a GPT3.5 model for medical image protocol assignment. We compare it with a fine-tuned BERT model and a radiologist. In addition, we have a radiologist review the GPT3.5 output to evaluate its decision-making process. Our evaluation dataset consists of 4,700 physician entries across 11 imaging protocol classes spanning the entire head. Our findings suggest that the GPT3.5 performance falls behind BERT and a radiologist. However, GPT3.5 outperforms BERT in its ability to explain its decision, detect relevant word indicators, and model calibration. Furthermore, by analyzing the explanations of GPT3.5 for misclassifications, we reveal systematic errors that need to be resolved to enhance its safety and suitability for clinical use

Evaluating the impact of Brainstorming and Scamper technique on promoting the creativity of architectural design skills

Background and Objectives: Creativity or Innovation is a controversial issue in various scientific fields, especially educational sciences and psychology. If we consider design as an imaginative creation of pre intended possible form of things to achieve different humanistic purpose; in this process, Creativity, as a multilevel concept, can be thought as a process that, although formed in the human minds, but is has also objective appearance in architectural patterns, methods and designs. In recent decades, the creativity concept Investigation, its functions and its influence on learning - as well as the ways of teaching creativity - have become a matter of great importance. The purpose of this research is to evaluate the levels of basic and altered creativity in the architectural design studio (3) course, based on the four main components of Torrance Creativity Thinking Test (Fluency, flexibility, originality and Elaboration) and Scamper tecnique. Materials and Methods: The required data of this research were collected by using the experimental research method in the form of the pre-test and post-test design through both Torrance's test  and drawing sketch among the students of Ardabil Azad university in the second semester of the academic year 2017-2018.  The research sample consisted of 40 students divided into two groups with two individual instructors. In first step, by using the pre-test, the level of students' creativity in each of 4 dimensions was measured. Then, in order to evaluate altered creativity, the first group was trained by common training - approved in higher education- and the second group instructed and evaluated through the experimental intervention – implementation of creativity training program (Teaching Brainstorming technique) in 6 sessions, by Related exercises. Finally, in second step, by using Scamper technique, drawing sketch test was given to both groups. Findings: Statistical data were analyzed by running both MANOVA and ANOVA techniques in SPSS. The Results obtained from the implementation of the experimental method, showed statistically significant difference between the experimental group and the control group (common and approved method of training) at the levels of Torrance creative thinking components. And among 4 components of Torrance creative thinking, Fluency has been improved by creativity training techniques more than other components in both multiple choice and sketching tests. In fact, it could be deducted that students, were able to draw more ideas related to the subject of design, after learning creative techniques in the post-test step, which showed an increase in the fluid level of creativity of this group. Also, based on data analysis, the originality dimension is at a lower level than other components. Conclusion: While creativity based instruction enhances architectural design skills and impacts on all   components of creativity (Fluency, flexibility, originality and Elaboration), the current teaching method not only can undermine the students' originality but also may lead the design process to imitation. In addition, in the originality dimension, due to factors which has influence on it such as time and space, the student's experience, adequate practice and group interaction, it is suggested to consider each of these components in assessment techniques.   ===================================================================================== COPYRIGHTS  ©2020 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers.  ====================================================================================

The Mean Drift: Tailoring the Mean Field Theory of Markov Processes for Real-World Applications

The statement of the mean field approximation theorem in the mean field theory of Markov processes particularly targets the behaviour of population processes with an unbounded number of agents. However, in most real-world engineering applications one faces the problem of analysing middle-sized systems in which the number of agents is bounded. In this paper we build on previous work in this area and introduce the mean drift. We present the concept of population processes and the conditions under which the approximation theorems apply, and then show how the mean drift is derived through a systematic application of the propagation of chaos. We then use the mean drift to construct a new set of ordinary differential equations which address the analysis of population processes with an arbitrary size

Towards geostatistical learning for the geosciences: A case study in improving the spatial awareness of spectral clustering

The particularities of geosystems and geoscience data must be understood before any development or implementation of statistical learning algorithms. Without such knowledge, the predictions and inferences may not be accurate and physically consistent. Accuracy, transparency and interpretability, credibility, and physical realism are minimum criteria for statistical learning algorithms when applied to the geosciences. This study briefly reviews several characteristics of geoscience data and challenges for novel statistical learning algorithms. A novel spatial spectral clustering approach is introduced to illustrate how statistical learners can be adapted for modelling geoscience data. The spatial awareness and physical realism of the spectral clustering are improved by utilising a dissimilarity matrix based on nonparametric higher-order spatial statistics. The proposed model-free technique can identify meaningful spatial clusters (i.e. meaningful geographical subregions) from multivariate spatial data at different scales without the need to define a model of co-dependence. Several mixed (e.g. continuous and categorical) variables can be used as inputs to the proposed clustering technique. The proposed technique is illustrated using synthetic and real mining datasets. The results of the case studies confirm the usefulness of the proposed method for modelling spatial data

Serum hyaluronic acid and laminin as potential tumor markers for upper gastrointestinal cancers

Background: Early diagnosis of patients with upper gastrointestinal cancer is important because many cases are diagnosed in advanced stages and have poor prognosis. Several studies have reported increased serum levels of hyaluronic acid and laminin in various cancers and the correlation of the levels with poor prognosis. However, little data on the use of serum hyaluronic acid and laminin levels for early detection of esophageal and gastric cancers are available. Methods: We assessed serum hyaluronic acid and laminin levels using enzyme-linked immunosorbent assay in 20 gastric cardia cancer, 23 gastric noncardia cancer and 20 esophageal squamous cell carcinoma incident cases and 25 controls in the Golestan Province, northern Iran, a high risk area for upper gastrointestinal cancers. Results: Mean serum hyaluronic acid and laminin concentrations in cancer cases were higher than in controls in crude analyses. Significant correlations were observed between hyaluronic acid levels and gastric noncardia cancer (Beta-coefficient = 0.390; P = 0.01) and esophageal squamous cell carcinoma (Beta-coefficient = 0.332; P = 0.05) and between laminin levels and gastric cardia cancer (Beta-coefficient = 0.454; P = 0.003) in multivariate models. For esophageal squamous cell carcinoma, gastric cardia cancer, and gastric noncardia cancer, area under ROC curve (AUC) of hyaluronic acid was 0.708, 0.694, and 0.770, and of laminin was 0.706, 0.828, and 0.671. Conclusions: Our study suggests that hyaluronic acid and laminin may be used to identify potentially high-risk groups of upper gastrointestinal cancers for further diagnostic work-ups, particularly in high incidence areas. Nevertheless, further studies with larger sample size and tumor staging information are warranted to clarify the clinical significance of hyaluronic acid and laminin in those cancers. © 2011 European Federation of Internal Medicine