Pseudospheric shells in the construction

The architects working with the shell use well-established geometry forms, which make up about 5-10 % of the number of known surfaces, in their projects. However, there is such a well-known surface of rotation, which from the 19th century to the present is very popular among mathematicians-geometers, but it is practically unknown to architects and designers, there are no examples of its use in the construction industry. This is a pseudosphere surface. For a pseudospherical surface with a pseudosphere rib radius, the Gaussian curvature at all points equals the constant negative number. The pseudosphere, or the surface of the Beltram, is generated by the rotation of the tracersis, evolvent of the chain line. The article provides an overview of known methods of calculation of pseudospherical shells and explores the strain-stress state of thin shells of revolution with close geometry parameters to identify optimal forms. As noted earlier, no examples of the use of the surface of the pseudosphere in the construction industry have been found in the scientific and technical literature. Only Kenneth Becher presented examples of pseudospheres implemented in nature: a gypsum model of the pseudosphere made by V. Martin Schilling at the end of the 19th century.

An Improved D-SMART Algorithm for Wireless Sensor Networks

In this paper, a secure and low energy dynamic slicing algorithm, namely, Improved D-SMART (IM-D-SMART) based on the Data Aggregation Protocol on Slice Mix Aggregate (D-SMART) is proposed to improve the security and confidentiality of wireless sensor networks and reduce the energy consumption of nodes in data collection and transmission in wireless sensor networks. According to the importance of data, the residual energy of nodes and the relative density of nodes, the data are dynamically partitioned to improve the D-SMART algorithm. Simultaneously, sending negative number splicing is used to compensate for the loss caused by the collision of data transmission between nodes. The simulation results show that IM-D-SMART outperforms D-SMART in terms of computation, privacy and communication cost.

Indonesia COVID-19 Task Force Statement Framing in September – November 2020

This study aims at examining how Indonesia COVID-19 Task Force, as the government's right hand man, uses Framing Theory in the press statement contents, to convince the public that the handling of COVID-19 in Indonesia has been good enough. The analysis was carried out on the content of the COVID-19 Task Force press statement from September to November 2020 when there were spikes in COVID-19 cases during that period. This research uses the social construction paradigm, to find out what kind of news framing is being carried out by the COVID-19 Handling Task Force related to news about the COVID-19 case through Murray Edelman's framing analysis. By using Murray Edelman's framing analysis, this study tries to reveal the framing of the press release of the COVID-19 Handling Task Force to form a direct public understanding that the handling of COVID-19 in Indonesia is well. The results of the analysis showed that the positive COVID-19 handling task force used a categorization framing with the titles of press statements, the majority of which only mentioned about the recovery of COVID-19 patients, such as: The Number of COVID-19 Patients Continues to Increase to 429,807 People; COVID-19 Testing Results Show 86% Confirmed Negative; Number of Testing Week Third of November Approaches WHO Standards.

Partial fuzzy quantifiers and their computation

Background: In computer science, one often meets the requirement to deal with partial functions. They naturally raise, for example, when a mistake such as the square root of a negative number or division by zero occurs, or when we want to express the semantics of the expression “Czech president in 18th century” because there was no such president before 1918. Method: In this paper, we will extend the theory of intermediate quantifiers (i.e., expressions such as “most, almost all, many, a few”, etc.) to deal with partially defined fuzzy sets. First, we extend algebraic operations that are used in fuzzy logic by additional value “undefined”. Then we will introduce intermediate quantifiers using the former. The theory of intermediate quantifiers has been usually developed as a special theory of higher-order fuzzy logic. Results: In this paper, we introduce the quantifiers semantically and show how they can be computed. The latter is also demonstrated in three illustrative examples. Conclusion: The paper contributes to the development of fuzzy quantifier theory by its extension by undefined values and suggests methods for computation of their truth values.

Populations in environments with a soft carrying capacity are eventually extinct

Consider a population whose size changes stepwise by its members reproducing or dying (disappearing), but is otherwise quite general. Denote the initial (non-random) size by $$Z_0$$ Z 0 and the size of the nth change by $$C_n$$ C n , $$n= 1, 2, \ldots $$ n = 1 , 2 , … . Population sizes hence develop successively as $$Z_1=Z_0+C_1,\ Z_2=Z_1+C_2$$ Z 1 = Z 0 + C 1 , Z 2 = Z 1 + C 2 and so on, indefinitely or until there are no further size changes, due to extinction. Extinction is thus assumed final, so that $$Z_n=0$$ Z n = 0 implies that $$Z_{n+1}=0$$ Z n + 1 = 0 , without there being any other finite absorbing class of population sizes. We make no assumptions about the time durations between the successive changes. In the real world, or more specific models, those may be of varying length, depending upon individual life span distributions and their interdependencies, the age-distribution at hand and intervening circumstances. We could consider toy models of Galton–Watson type generation counting or of the birth-and-death type, with one individual acting per change, until extinction, or the most general multitype CMJ branching processes with, say, population size dependence of reproduction. Changes may have quite varying distributions. The basic assumption is that there is a carrying capacity, i.e. a non-negative number K such that the conditional expectation of the change, given the complete past history, is non-positive whenever the population exceeds the carrying capacity. Further, to avoid unnecessary technicalities, we assume that the change $$C_n$$ C n equals -1 (one individual dying) with a conditional (given the past) probability uniformly bounded away from 0. It is a simple and not very restrictive way to avoid parity phenomena, it is related to irreducibility in Markov settings. The straightforward, but in contents and implications far-reaching, consequence is that all such populations must die out. Mathematically, it follows by a supermartingale convergence property and positive probability of reaching the absorbing extinction state.

Active Learning dalam Pembelajaran Matematika SD Melalui Permainan Engklek Mamun

The weak ability of the students on the summation material and reduction in the background of this research. Mathematics is abstract, so in mathematics learning the necessary medium/intermediary that serves to confine so that facts clearer and more easily accepted by students. Media used is the game usually Mamun, which is a game conducted in groups in the form of advanced crank if the number of positive and crank backward if the number is negative. Numbers is a row of students holding positive and negative number flags. Each student holds a number. Students who do not hold the number do the forward or backward crank according to the prescribed number. The method is qualitative. The result is that through the game Engklek Mamun students can do the counting operation summation and reduction on the number line.

A new study on the superplasticity of TiAl alloys

The superplasticity of Ti-46.7Al-2.2Cr(at.%) alloy was studied by mathematical induction. It is found that Zener Hollomon relative formula and there are serious deflections. According to the true superplastic stress and true strain curves, the deflection values of n=-7.46 and B=1439MPa are obtained, indicating that the limit of n>0 has been exceeded, which needs to be characterized by a negative sign. This shows that it conforms to the principle that the smaller n is, the better superplasticity is, but the problem that it has become a negative number needs to attract the attention of peers meantime B is a better match.