scholarly journals On the link between mean square-radii and high-order toroidal moments

2021 ◽  
Vol 2015 (1) ◽  
pp. 012021
Author(s):  
Dmitrii Borovkov ◽  
Adrià Canós Valero

Abstract Multipole expansions of the source play an important role in a broad range of disciplines in modern physics, ranging from the description of exotic states of matter to the design of nanoantennas in photonics. Within the context of the latter, toroidal multipoles, a third group of multipoles complementing the well-known electric and magnetic ones, have been widely investigated since they lead to the formation of non-radiating sources. In the last years, however, the photonics community has brought to light the existence of a fourth type of multipoles that is commonly overlooked. Currently, different groups have provided different mathematical expressions to describe such sources, and they have been coined with different names; on the one hand mean-square radii, and on the other hand, as high order toroidal moments. Despite their clear physical similarity, a formal relation between the two has not yet been established. While explicit formulas for both types have been derived, they are not expressed in the same basis, and therefore it is not possible to draw a clear physical connection between them. In this contribution, we will bridge this gap and rigorously derive the connection between the two representations, taking as an example the cases of the nth order mean square radius of the electric dipole and the nth order electric toroidal dipole. Our results conclusively show that both types of representations are exactly equivalent up to a prefactor.

2012 ◽  
Vol 591-593 ◽  
pp. 1299-1302
Author(s):  
Wen Kai Wang ◽  
Huan Xin Peng

The convergence performance of distributed consensus algorithm with adaptive quantization communication depends on the convergence rate of the distributed consensus algorithm. In order to improve the convergence performance of distributed consensus under adaptive quantization communication, based on the one-bit adaptive quantization scheme, we propose the high-order distributed consensus to update the state of every node. We analyze the convergence performance and calculate the mean square error of the high-order distributed consensus algorithm with one-bit adaptive quantization. The high-order distributed consensus with one-bit adaptive quantization achieves a consensus in a mean square sense. Simultaneously, Simulations are done about the high-order distributed consensus based on one-bit adaptive quantization. Results show that the high-order distributed consensus algorithm based on one-bit adaptive quantization can reach an average consensus, and its convergence rate is higher than those of the first-order adaptive quantized distributed consensus algorithm and second-order adaptive quantized distributed consensus algorithm.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Grit Kalies

AbstractQuantum mechanics for describing the behavior of microscopic entities and thermodynamics for describing macroscopic systems exhibit separate time concepts. Whereas many theories of modern physics interpret processes as reversible, in thermodynamics, an expression for irreversibility and the so-called time arrow has been developed: the increase of entropy. The divergence between complete reversibility on the one hand and irreversibility on the other is called the paradox of time. Since more than hundred years many efforts have been devoted to unify the time concepts. So far, the efforts were not successful. In this paper a solution is proposed on the basis of matter-energy equivalence with an energetic distinction between matter and mass. By refraining from interpretations predominant in modern theoretical physics, the first and second laws of thermodynamics can be extended to fundamental laws of nature, which are also valid at quantum level.


2021 ◽  
Vol 11 (5) ◽  
pp. 2239
Author(s):  
Hailin Zhao ◽  
Hua Su ◽  
Guoding Chen ◽  
Yanchao Zhang

To solve the high leakage and high wear problems faced by sealing devices in aeroengines under the condition of high axial pressure difference, the two-stage finger seal is proposed in this paper. The finite element method and computational fluid dynamics (FEM/CFD) coupling iterative algorithm of the two-stage finger seal is developed and validated. Then the performance advantages of two-stage finger seal compared to the one-stage finger seal are studied, as well as the leakage and the inter-stage pressure drop characteristics of two-stage finger seal are investigated. Finally, the measure to improve the inter-stage imbalance of pressure drop of two-stage finger seal is proposed. The results show that the two-stage finger seal has lower leakage and lower contact pressure than the one-stage finger seal at high axial pressure difference, but there exists an inter-stage imbalance of pressure drop. Increasing the axial pressure difference and the root mean square (RMS) roughness of finger element can aggravate the imbalance of pressure drop, while the radial displacement excitation of rotor has little influence on it. The results also indicate that the inter-stage imbalance of pressure drop of the two-stage finger seal can be improved by increasing the number of finger elements of the 1st finger seal and decreasing the number of finger elements of the 2nd finger seal.


2020 ◽  
Vol 17 (2) ◽  
pp. 325-338
Author(s):  
Raditya Novidianto ◽  
Rini Irfani

Indonesia is known as an agricultural country. This means that most of the population work in the agricultural sector related to food. However, food insecurity still occurs in Indonesia. With the COVID-19 pandemic, the Food and Agriculture Organization (FAO) stated that there was a threat of food scarcity which had an impact on food insecurity conditions. This would undermine the second goal of the SDGs, which is to end hunger and create sustainable agriculture. The purpose of this study was to determine the spatial pattern of food insecurity in each province in Indonesia using the bicluster method. The data used are data from Susenas and Sakernas by BPS in 2019. Several studies show that the bicluster method with the CC algorithm shows that each province group has a different characteristic pattern. In the bicluster approach, the researcher runs parameter tuning to select the best parameter based on the Mean Square Residual in Volume (MSR / V). The CC algorithm tries to get a bicluster with a low MSR value, therefore the best parameter is the one that produces the smallest MSR / V value, in this study the smallest MSR / V is 0,01737 with δ = 0,01. The application of the CC biclustering algorithm to the food insecurity structure in Indonesia results in 5 bicluster. Bicluster 1 consists of 15 provinces with 8 variables, Bicluster 2 consists of 10 provinces with 5 variables, Bicluster 3 consists of 3 provinces with 7 variables, Bicluster 4 consists of 4 provinces with 4 variables and Bicluster 5 consists of 2 provinces with 5 variables. Biculster 4 represents a cluster of food insecurity areas with the characteristics of the bicluster P0, P1, P2 and calorie consumption of less than 1400 KKAL.


2020 ◽  
Vol 12 (33) ◽  
Author(s):  
Yudha Andana Prawira ◽  
Titim Kurnia

The National Education World is currently trying to improve the ability of its students to think critically and creatively. One of these efforts has been pursued through evaluations that also lead to critical reflection. This research is a descriptive analysis of the final semester evaluation questions that are examined from the point of view of high-level thinking [HOTS]. The reference to the HOTS criteria is that the researcher refers to the opinions of King and his friends. From the manuscript data, the issues examined are samples from the Bandung area. The results of the analysis show that 10 out of 15 HOTS ranges proposed by King are already included in the scripts made by the teachers. On the one hand, it shows the teacher's creativity in compiling questions. On the other hand, all these questions do not refer to the HOTS criteria as planned. Therefore, there is a need to increase teachers' skills in compiling scripts as HOTS. This increase can be done through teacher training.Keywords: Evaluation, HOTS, critical thinking and creativity thingking


2013 ◽  
Vol 284-287 ◽  
pp. 3111-3114
Author(s):  
Hsiang Chuan Liu ◽  
Wei Sung Chen ◽  
Ben Chang Shia ◽  
Chia Chen Lee ◽  
Shang Ling Ou ◽  
...  

In this paper, a novel fuzzy measure, high order lambda measure, was proposed, based on the Choquet integral with respect to this new measure, a novel composition forecasting model which composed the GM(1,1) forecasting model, the time series model and the exponential smoothing model was also proposed. For evaluating the efficiency of this improved composition forecasting model, an experiment with a real data by using the 5 fold cross validation mean square error was conducted. The performances of Choquet integral composition forecasting model with the P-measure, Lambda-measure, L-measure and high order lambda measure, respectively, a ridge regression composition forecasting model and a multiple linear regression composition forecasting model and the traditional linear weighted composition forecasting model were compared. The experimental results showed that the Choquet integral composition forecasting model with respect to the high order lambda measure has the best performance.


Author(s):  
Panagiotis Razelos

In this work we re-examine the main fin equation qf = ηfAfΔT, proposed by Gardner [1] that has been used for the last sixty years to determine the performance of fins. The fundamental concepts of extended surface heat transfer are introduced, and their mathematical expressions are derived. The vital role of fin effectiveness, a term also introduced by Gardner [1] is established. It is shown that the effectiveness is inextricably linked in proving the validity of the simplifying assumptions that most of the fins’ endeavors are based on. It is also shown that the common practice of using the efficiency to predict the fin’s performance leads to serious errors. A novel approach to fin analysis, based on a proposed transformation of coordinates, is presented, which can be employed to considerably simplify the pertinent differential equations and obtain more friendly expressions describing the fin’s performance. The heat dissipation is expressed in a non-dimensional form and for several practical cases polynomial expressions have developed, that will help students to engage in rudimentary fin designs. It is also shown that, the one-dimensional approach can be used to obtain solutions involving extended surfaces made from anisotropic material. Three examples serve to illustrate the usefulness of our method.


Sign in / Sign up

Export Citation Format

Share Document