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.

The power industry is facing problems such as fossil fuel reduction, greenhouse gas emissions and the lack of automated analysis of the power grid. To meet the existing challenges, creating a new infrastructure is essential. The concept of smart grids aims to update existing power grids by integrating advanced communication infrastructure with the existing grid, making power grids more reliable, efficient, and environmentally friendly. Integration of power networks and communication networks, while it has many benefits, it has disadvantages in system security and protection. In this paper, after familiarizing with the smart grid communication infrastructure, their features and applications, the existing threats against the security of communication networks are introduced, and suitable actions are discussed, including prevention, detection, and counteract against security risks. At the security risks prevention stage, solutions such as encryption and blockchain have been studied and reviewed with the purpose of maintaining access to network information for authorized users. In the field of identifying attacks in the smart grid due to the need for a smart and fast solution, deep learning as one of the smart, dynamic and powerful tools with its applications in improving smart grid security has been investigated.

Introduction: Twitter is a global communication network that has become an instrument of diplomacy and promotion of international social capital of countries in the current era. Twitter has played an important role in US foreign policy, especially after the JCPOA. The problem is that the JCPOA, as the most important achievement of Iranian diplomacy, is in danger. In the meantime, Iranian diplomacy has achieved a good result with the help of the growth of communication technology. The main question in this paper is “what role does Twitter play in the power of Iranian diplomacy in the JCPOA, a capacity to strengthen international social capital when the United States withdraws from it?”Method: The research method of this paper is a qualitative content analysis of the tweets of the political leaders of Iran and the United States. A total of 5700 tweets were analyzed using Maxqda 18 software. Based on the strategic narrative approach and soft power, the analysis of the content of the tweets shows that Iran has defined an active diplomacy to influence the United States in withdrawing from the JPCOA to restore attitudes, trust, and identity, which are important elements in producing international social capital.Findings: Promoting this important cause by relying on the sources of social capital production has created a new image of it in the international community. The main elements of social capital, i.e. participation and trust, have the ability to spread in the international space. The use of the same elements allows the concept of soft power, formed in the form of elements such as politics, culture and values, to be used with these resources. Finding and creating new dimensions. This has serious implications in the context of participation. The higher the level of government participation in international organizations, treaties and institutions, the greater the effectiveness of social capital, is worth considering (Mushirzadeh &Vaseinejad, 2018). Its dynamics is based on the goodwill of members to reciprocate positive interactions (Bigart & Deliberg, 2004). It is also a social capital for international security (Shirkhani & Vaseizadeh, 2012). Considering the importance of building trust, it is a ubiquitous category that can be effective in using international social capital for communication networks.The Iranian narrative about itself, the United States, and the JCPOA has been active in the context of generating soft power in the form of partnership development and trust as two effective factors for generating soft power. In other words, as international trust and the participation of countries in the international arena can be considered in the context of the soft power of these countries. Soft power is generated on the basis of trust and trust is a prerequisite for soft power (Moshirzadeh & Vaseinejad, 2018).Conclusion: Iran ultimately seeks a position (of equality based on mutual respect) and seeks to create or promote an alternative order that serves its national interests rather than the prevailing order (acting in accordance with international law rather than coercion). The success of the Iranian narrative requires the deliberate creation and dissemination of the narrative in the new media ecosystem, on behalf of Twitter, and maximizing its impact on the audience (persuasion). This requires adopting a point of view and a method based on a systematic scientific method, because trial and error in the new media ecosystem-and especially in the current situation-can be costly not only for Iran but for the entire world. Iranian foreign policy relies on the triangle of nationalism, Islamism, and commitment to the structure of government in the modern world to explain self-awareness and to guide governments and nations toward a true image.

As wireless networks with high data rate get widely deployed, improving the performance of TCP over these networks plays vital role. Wireless link losses have dramatic adverse impact on TCP performance due to the difficulty in distinguishing the congestion losses from wireless link losses. We first, studied the various existing Bandwidth Estimation Algorithms over the wireless networks. In this paper, we propose an enhanced bandwidth estimation technique with congestion control algorithms to improve TCP performance over wireless link with random loss. We propose, a new technique called TCP- BWIW to estimate the bandwidth and the congestion window is set accordingly. The performance of TCP-BWIW is analyzed, and it mitigates the Network congestion.

We address the throughput maximization problem for downlink transmission in DF-relay-assisted cognitive radio networks (CRNs) based on simultaneous wireless information and power transfer (SWIPT) capability. In this envisioned network, multiple-input multiple-output (MIMO) relay and secondary user (SU) equipment are designed to handle both radio frequency (RF) signal energy harvesting and SWIPT functional tasks. Additionally, the cognitive base station (CBS) communicates with the SU only via the MIMO relay. Based on the considered network model, several combined constraints of the main problem complicate the solution. Therefore, in this paper, we apply heuristic guidelines within the convex optimization framework to handle this complexity. First, consider the problem of maximizing throughput on both sides of the relay separately. Second, each side progresses to solve the complex problem optimally by adopting strategies for solving sub-problems. Finally, these optimal solutions are synthesized by proposing a heuristic iterative power allocation algorithm that satisfies the combinatorial constraints with short convergence times. The performance of the optimal proposed algorithm (OPA) is evaluated against benchmark algorithms via numerical results on optimality, convergence time, constraints’ compliance, and imperfect channel state information (CSI) on the CBS-PU link.

The production of energy from renewable sources, such as the energy from electricity-water, which reduces the amount of CO2, is called clean energy. Today, technologies and methods that reduce energy consumption in computer networks and Co2 production in the environment are called green networks. Now, high consumption of energy in networks and increasing production of Co2 is an important global challenge. This research analyzes the three important principles of optimization, not draining resources and not wasting resources from green network standards. This research shows that high-performance optimal routing algorithms do not always guarantee green standards in networks, and the principles of optimality and greenness must be combined. Therefore, by combining the principles of being green and the principles of linear optimization, a new green optimal routing algorithm in computer networks is presented. Next, three types of USCP, OUMR and OMMR routing algorithms are analyzed according to green standards and it is proven that they are not green despite being optimal. Then, based on the strengths and weaknesses of these methods, a new green optimal routing algorithm is presented. The simulation results and comparisons show that the new method, while increasing the network efficiency, also improves the green standards of data transmission

Intelligent traffic systems (ITS), sometimes called intelligent transportation systems, apply communications and information technology to manage traffic flow, encourage drivers to use alternate forms of transport, and enable people to find the services and information which they need to drive safely, avoid traffic jams, and perform their daily routine with fewer hassles and with more peace of mind. Vehicular Ad-hoc Network which is an application of Mobile Ad-hoc Networks provides wireless Ad-hoc communication between vehicles. VANET is a mobile wireless technology which is designed to improve safety of transportation with exchanging real time data between vehicles and providing different services to the users. It has special characteristics like high mobility and provides a broad range of services to the users and it has been emerged as one of the research interests in the field of computer and telecommunication networks. In this paper we present different aspects of ITS and VANET to help the researchers to understand the architecture, communication technologies and applications of these networks.