فصلنامه پدافند غیرعامل
سال چهارم شماره 4 (پیاپی 16، زمستان 1392)

Nowadays, the assets of an organization are assessed not only through physical possessions but also by the information they have. Information is prone to threat as are the other assets of every organization. These threats include attack from outsiders or insiders who may intend to affect the passive defense (security, safety and survivability) of the information assets an organization possesses. One of the threats to which information assets are exposed to is information compromise, the threat that causes unauthorized disclosure of confidential information. There are various ways for information compromise, therefore; it is necessary to identify and properly organize sensitive information in order to reduce the threats made by the information compromise events. The sensitive information should be protected using security tools known as DLP methods that are developed by security providers.

In this article, a new method is introduced for extracting features from vocal signals and discriminating speakers, which has a vast application in spy operations and passive defense sciences (for example; not only by using this method, it is possible to prevent the imitation of particular people’s voice such as commanders but also the detection of every speakers’ voice when eavesdropping the place where a number of people are discussing an important matter can be made possible). The introduced method is the improved version of MFCC method. Experimental studies say that the most useful information of vocal signals is in their low frequencies and their high frequencies are not useful in speaker recognition procedures. The method introduced in this article, the Mel frequency filter which is used in MFCC, is changed and improved. The results of MFCC and the proposed method are compared for 20 speakers and the speaker recognition percentage has improved approximately 4.5% for the linear and 9% for the exponential proposed methods.

Without a doubt, proper and accurate site selection play an undeniable role in increasing urban safety rate and it can decrease the hazards of human threats and natural disasters. Hence, site selection of the urban gas stations requires great attention to passive defense considerations which has been ignored in Iran. In this paper, criteria for the urban gas station site selection are deduced based on appropriate analysis of environment and are weighted using the analytical hierarchical process (AHP). Afterwards, using the capabilities of GIS, spatial analysis and identification of the suitable areas in region14 of Tehran municipality are accomplished as a case study. The results of this study show that, the location of two existing gas stations has not been properly determined in the region. Moreover, in this study, a proposal for the establishment of zones for the new gas stations is presented.

Fuel storage tanks are among the most important structures present in refinery industrial complexes or power plants that might be exposed to military or non-military explosions. As a result, examining the methods of hardening these tanks in refineries can be of paramount importance. This article deals with the study of concrete dike to minimize the blast load exerted on these tanks and it was realized that dike with a thickness of 35 centimeters and a height of 5 meters and resistance of 35 mega-Pascal could withstand an explosion resulted from GP500 and be effective in reducing maximum pressure and impact. This article uses the Autodyn software for modeling and analysis.

Landmine are considered as those military weapons that when used during a war, their mission is not accomplished after the war and will always be a threatening element. Thus detection and neutralization of landmine before it causes an insident is one of the most evident examples of passive defense. On the other hand, since common methods of landmine detection face many risks, therefore selection of a method that has the lowest risk, is one of the main considerations of passive defense. Passive Infrared thermography technique which can detect buried landmines without direct contact with the soil, is one of the new and safe methods of landmine detection.In the present paper, to detect landmines, we presented a method which contains different stages of contrast stretching, image smoothing, noise reduction, image segmentation, extraction of feature image from a sequence of images and object identification. In this regard some of the image processing techniques such as linear stretching, histogram equalization, morphological filters, watershed segmentation method based on markers and Karhunen-Leove transformation have been used.

Having a safe and appropriate place to live is considered among the most primitive and essential needs of every human. The expansion of the Earth population followed by increased urban life has turned city districts and neighborhoods into a place of social, cultural and ethnic conflicts and has contributed to setting the stage prone to the emergence of urban abnormalities such as crime, delinquency and theft. The passive defense, as one of the effective ways of defense against any kinds of threat including natural and human, has always been noticed by the countries of the world. In this regard, the threat management caused by environmental hazards has always been a major objective of planners. According to the principles of passive defense, in the process of hazards management, the defense element has various levels which include before, while and after the hazards that are the most cost effective and peaceful way of defense related to the pre-occurrence of hazards. The issue of site selection is one of the main principles of passive defense and considered as a pre-crisis measure. The proper site location of police centers, not only provides better police services to citizens but also is very impressive in the subject of passive defense. This requires the identification of high crime areas and deployment of agents at proper locations. Therefore; the high crime areas of the City of Kazeroon are first identified and then using the Geographic Information System (GIS), the best locations to deploy police stations are determined. In this paper, six criteria for the site location of police stations in accordance with passive defense are used which include access to main streets, the distance between the existing police stations, proximity to high crime areas of the city, distance from training centers, slope and the kind of land utilization. And finally, the lands of Kazeroon are categorized, according to optimality, into ten groups ranging from weak to very good in order to deploy police centers and five new locations to establish new police centers in the City of Kazeroon are proposed, as well.

One of the most sustainable measures of passive defense in the strategic domains is to employ buried structures, in particular, tunnels. These tunnels are designed and built in mountain regions with high burms. On the other side, the adversary can take countermeasures to develop their detection methods of these structures. Also increasing the capabilities of their offensive instruments and equipments is their next step.The subject of this study is to investigate, evaluate and model the effectiveness of geophysical detection technologies of buried facilities. Airborne and space based methods are mostly attractive by the adversary. Construction and using these underground spaces, apply different effects on parameters of surface/subsurface of the earth. Using modeling, the Identification capabilities of different geophysical technologies in detecting objects, targets and underground facilities are assessed. In conclusion, the countermeasure methods (Camouflage, Concealment and Deception), have been presented using detection of underground facilities via these technologies.