The world is embroiled in a pandemic of a new coronavirus at the end of 2019 and early in 2020, with such a large scale that it has severely involved the political, economic, and social systems in most countries around the world. The scale of the crisis is so widespread that many experts believe that the post-corona world will be substantially different from the pre-corona world. In the face of this massive epidemic, how people perceive risk and how to risk is communicated, plays a central role in deciding and choosing people's behavior. Fighting with this emerging phenomenon requires mobilizing all the possibilities of society and helping all people in the field of empathy and altruism. In this article, we briefly review aspects of the important concept of risk perception and communication in this pervasive crisis.

In this paper, a private telephone communication network of an electrical energy distribution company has been studied analytically and through discrete event system simulation. Considering the pitfalls and difficulties associated with the analytical approach in designing such a network and the power and performance of a simulation methodology in this regard, a simulation model was developed using GPSS/H simulation language. After data collection and analysis, model development and validation, initial transient study and design of experimental phases, the model was applied to determine the operating performance of the current system, as well as to evaluate the performance of any newly designed network before the installation and implementation of the new equipment.

Purpose: The present study was conducted with the aim of Network data analysis application in drawing the communication network to measure evolution in middle childhood. Methodology: The present horoscope was a descriptive-analytical psychometric study. The socio-statistics of the present study were all students of Tehran city in elementary school (6 to 12 years old) in the academic year of 2019-2020. The sample was 585 people who were selected by multi-stage cluster sampling method. Middle childhood development questionnaire was used to collect data. The data was analyzed using confirmatory factor analysis of the five-factor structure (flexibility, intimacy and friendship, separation times, physical health and empathy). The reliability of the questionnaire was calculated using Cronbach's alpha coefficient. Findings: In this research, 585 people were selected as a sample group in the form of multi-stage clusters. The research tool was measuring the transformation in middle childhood. The methods of exploratory and confirmatory factor analysis, criterion validity, convergent-divergent validity were used to check the validity of the scale, and reliability was checked with two methods of internal consistency (Cronbach's alpha) and stability of results (retest) with a two-week interval. Exploratory factor analysis using principal component analysis and varimax rotation led to the extraction of 5 factors (empathy, flexibility, intimacy and friendship, physical health and leisure time).  Conclusion: The results of confirmatory factor analysis confirmed the results of exploratory factor analysis. The reliability analysis of the test showed that the Cronbach's alpha coefficient of the subscales is higher than 0.7. Also, in all subscales, the Pearson correlation coefficient between the two implementations was higher than 0.85. The correlation between the subscales of measuring the development in the middle childhood period confirmed the convergent evidence of the questionnaire. Based on the results of the research, research evidence supports the simultaneous examination and consideration of all five subscales of the Persian version of the Middle Childhood Development Assessment.

This paper proposes a new notion for power. The Rarest power sources that can be hidden behind political messages. There are different puzzles of power in terms of political actors. In the unsorted Rubik of power the representative sides are Showed as individuals or organizations that have the power arrangement. The Rubik levels from the perspective of this research are: 1. Government offices and security forces and Army troops 2. 3. Lay out of the subsidiary organizations and the judiciary, including Justice and Attorney 4. Parliament as a representative of the Supreme Leader Amamjmh 5. 6. 7. governors as torque or driven Rubik's people. Therefore, this study answers the question that political connections cast as power levels, how ideas form the Rubik's Cube? on another level where it is and complicated equations. Distinguishing feature of this idea for the space and power of adding depth to its communication, rotation level homes as assets and trade-offs between power levels in line asked.

Background: Existence of heavy metals, may have adverse effects on consumers. This study was carried out to determine some heavy metals concentrations (cadmium, chromium and lead) in Mashhad drinking water network.Materials and Methods: In this cross study, samples were collected from different points of urban drinking water network according to the standard methods, and tested by atomic absorption spectrophotometeric method.Results: Cadmium and chromium concentrations did not exceed national and international standards, only lead concentrations were slightly higher than standard rate in some areas and its mean difference spring and summer was significant (p=0.03).Conclusion: It is necessary to do needful measures by responsible company because of the metals importance.

Advances in quantum computer technology are threatening cryptographic systems based on mathematical complexity. As an alternative, quantum cryptography has been proposed and developed. Among the reported quantum cryptography systems, quantum key distribution (QKD) constitutes a symmetric key system that can securely distribute a secret key on a quantum channel. While there have been many studies on confidential communication using QKD, only a few of them address its application to the digital signature. In this paper, we propose a new digital signature method with public parameter and signature key through shared symmetric key from QKD. We also analyze the proposed plan from security.