Scientific Journal of Passive Defense
Year:2021 | Volume:12 | Issue:2 (46)|Papers Count:8

One of the common network security and anonymity methods, is the use of anonymity networks. Pars Anonymity Network is a domestic anonymizer network, developed by Iranian specialists. One of the main weaknesses of anonymous networks is their traffic differentiation and recognition among other network traffic. Uncovering the traffic passing through a network, means recognizing the nature of that traffic, and if this traffic is the traffic of an anonymity tool, it means that confidential information is being exchanged in the network, which puts anonymity in danger. One of the evaluation criteria of anonymity networks, is undifferentiability and indistinguishability of anonymous network traffic from normal traffic. Traffic classification-which has various applications-is one of the most powerful methods in data mining. Traffic management via detecting network traffic flow, is considered as one of these applications. In this research, by using data mining techniques, in the first step the detection rate of Pars Anonymity Network is assessed in comparison to the Onion Router, Invisible Internet Project, JonDo and HTTPS traffics, and in the next step, the classification rate of four different services in the desired anonymizer is studied in more detail. Results suggest that the classification accuracy rate of these experiments in the first step is 100% and in the next step-with the use of Random Forest algorithm-is 95%. Furthermore, by evaluating the used specifications in every experiment, the effectiveness of these specifications regarding the overall accuracy and the model construction time is assessed.

Passive defense measures in architecture and urban planning can be effective in reducing the risk against a variety of natural hazards, in addition to its premiere purpose in reducing the damage of man-made threats like wars. Medical and health centers as one of the basic and vital needs in emergencies should be designed and built in such a way to meet the defined standards of security against accidents and threats and achieve the overall goals of passive defense. In emergencies, these centers should not be vulnerable at all or have the least vulnerability depending on the functional level. In fact, a safe hospital is a kind of medical shelter that makes the conditions of hospitalization and treatment possible away from external threats in times of crisis. Shahid Beheshti Medical Research and Training Center in Qom is the largest medical center in the Qom province. Because of the need to redesign this hospital according to the principles of passive defense, the relevant design requirements based on factors such as location, dispersion, camouflage, fortifications, facilities, architecture design, repairability, etc. have been studied, and based on the presented principles, appropriate solutions are provided. The research method is descriptive-analytical and the data are obtained from documentary sources, libraries and field observations. Using the descriptive-analytical method, it is shown that the design of the hospital in terms of the building form, location, emergency storage, access, proximity to public spaces and parking area, is consistent with the principles of passive defense. Studies also show that the hospital does not comply with the principles of passive defense in terms of facade, safe haven, camouflage, green space design and safety indicators. We conclude that in the design and implementation processes, all the principles of passive defense for the protection of buildings of high importance should be considered.

Nowadays, gait recognition is one of the biometric methods that receives more and more attention of the researchers in the fields of machine vision and pattern recognition. However, the main challenges of this technology are the variations caused by covariate factors such as the walking pace, and the clothing and bag/parcel carrying conditions. This research tries to provide issues in three basic parts: preprocessing, feature extraction, and classification. Using the Cassia data set, which is a large set with different gestures and carrying conditions, first a new spatial-temporal database is organized with horizontal profiling of the silhouette. Next, feature extraction is performed by PCA. Finally, the SVM algorithm is used for classification and identification. The test results show the efficiency of the proposed algorithm under different conditions.

In order to establish information security, we need to implement a cryptography algorithm in either the software or the hardware. In 1996, Kocher presented the Side Channel Attacks (SCA) on the cryptography systems in which the leakage of some important information was used. Power analysis is one of these attacks. In order to prevent these kinds of attacks, the designers and implementers presented some countermeasures such as hiding and masking. Afterwards, attackers showed that these countermeasures, especially masking, could not reach the security goals in the presence of Glitch. To resolve this challenge Nikova et al. presented the threshold implementation method in 2006. They used three subjects, namely threshold cryptography, hidden share, and multi-party computation in their new countermeasure. In fact, the threshold implementation is a kind of masking with some extra features to establish the information security in the presence of Glitch. In the recent years, the National Institute of Standards and Technology (NIST) has started some activities in the field threshold implementation. Standardization in this field is the main goal of NIST. In this paper we introduce the threshold implementation method as a countermeasure against side channel attacks and review its challenges and advantages in comparison to the previous countermeasures.

The issue of passive defense has become very important due to the increasing number of terrorist attacks around the world and the possibility of targeting various structures. Water storage tanks are such targeted structures which are very vulnerable to explosions and the destruction of this type of structure may cause unrecoverable losses in terms of humanistic, economical, and environmental parameters. The purpose of this study is to investigate the effect of explosions on cyclic stresses and the displacement created on the body of a cylindrical reinforced concrete tank with water content due to hydrodynamic forces by considering the amount of water filling and the dimensions of the tanks. Also, according to the distances of 5 and 10 meters from the center of the explosion, the cyclic stresses created in the body of the tanks are investigated. For this purpose, Abacus commercial software has been used to numerically simulate three tanks with the heights of 4, 6, and 8 meters and a fixed radius of 3 meters with a filling percentage of 0, 25, 50, 75, and 100 percent of water. The results show that with increasing the percentage of water filling, the hardness of the tank has increased and has caused the displacement of the body to have a decrease of 31. 25% for a fully filled tank compared to an empty tank. Water filling also reduces the sensitivity of tanks to instability. The results show that the cyclic stresses of the tank body are affected by blast waves from the outside and water pressure from the inside so that the presence of water in the tank has caused the cyclic stresses in the body to increase by about 20 MPa.

Today, the electric energy as the most important and sensitive asset has the greatest impact on the lives of people and society. Electromagnetic threats can be caused by natural phenomena such as lightning, solar storms and electromagnetic systems such as narrowband and ultrawideband systems. This article, which combines the two specialized perspectives of passive defense and strategic management, scores the set of strengths, weaknesses, opportunities and threats with the help of experts and by analyzing the data in SPSS and EXCEL software. Strategies have been oriented towards defensive strategies. Finally, by combining these points, 42 strategies have been extracted with an emphasis on defensive strategies and their relationships with the five main goals of passive defense (reducing vulnerability, increasing deterrence, continuing necessary activities, facilitating crisis management and promoting national sustainability) have been determined and then the necessary capabilities (human capital, organizational and management development, knowledge and physical facilities) for the implementation of strategies and the optimal expected status of strategies in 1414 have been illustrated.

Considering the particular significance of power systems in each country and bearing in mind the Warden’ s theory, it is necessary to investigate these systems with the aim of presenting ways to improve their performance by passive defense approach. The present study has been prepared to investigate and propose strategies for supply and localization capability in power systems with the passive defense approach. After environmental analysis and identification of strengths, weaknesses, opportunities and threats, the proposed strategies were developed using the SWOT matrix. To prioritize these strategies, the opinions of relevant elites in the electricity industry have been gathered by means of questionnaires. Also, for a more detailed investigation of prioritization, each strategy was re-rated based on indicators and criteria of prioritization, such as: primacy and latency of strategies in terms of time, time to achieve the first output, cost imposed on the organization, variety of use in other combat areas, the possibility of benefiting from national capacities, the degree of dependence of the strategy on non-indigenous knowledge and technology, and the level of sustainability of the strategy. Finally, the prioritization of strategies from high to low rank has been done in four categories namely supportive measures, law-related measures, reinforcement measures and creative measures.

The safety of a building against the phenomenon of fire is a stereotype that as individuals, we read, see and sometimes painfully feel its absence. The engineering of a building against fire is one of the architectural infrastructures in the sustainability of buildings which has been proposed and agreed on the scale of "sustainable metropolises" since 2015. The present study is based on the method of structural equations and data analysis by SPSS and Lisrel software (version 10 for mac). In this method the data were collected in the form of a questionnaire and in terms of Likert among the heads of stations of the Tehran Municipality Fire and Safety Services and the academic elites. Resilient design of the architecture of a building against the spread of fire, design of automatic fire extinguishing systems and also the appropriate protection of the building structure against the heat caused by the flames are the fields of science needed for acquiring the knowledge of long-lasting construction. Space segmentation of the building and the functional arrangement within, have the highest coefficient impact among the variables affecting the building stability against the fire hazard. The two variables of “ automatic fire extinguishing systems response in the initial stages of lighting” and “ optimal protection of the building structure against the heat reflected from the fire” come next by the effectiveness ranking.