فصلنامه پدافند غیرعامل
سال پنجم شماره 3 (پیاپی 19، پاییز 1393)

In broad cross-organization environments, establishing trust among distributed services, has become a basic need. Access control and provision of data security, are notable challenges in these environments. Due to different security policies in inter-organizational environment, traditional access control mechanisms are often unable to satisfy users security requirements. Trust negotiation is a crucial and promising approach in trust establishment and secure interactions between entities for which there is no pre-existing knowledge or experience. In this paper, a new access control model with passive defense approach based on trust negotiation mechanisms with XACML standard architecture to overcome aforementioned challenges is proposed. The model can overcome aforementioned challenges by obtaining necessary level of trust for users before processing their requests to access designated resources. Performance and flexibility of our model show that its applicability is more convenient for development of einteractions over the internet.

In recent era، threats and risks are not only military but rather the access of competitor and foreign organizations to knowledge and experience of them can also be a kind of threat and risk. With respect to resources of organization، we realize that resources are valuable for us only when they cause efficiency increase and provide us with possible investment in opportunities and confronting with threats. The most efficient method of encountering various kinds of enemy threats، is employing the process of knowledge management in principles of passive defense whose employment will contribute to protecting vital installation،intellectual assets and reducing threat effectiveness. In this research، significance and place of human resources as a main and common element of knowledge management and passive defense will be discussed، and in addition to presenting the knowledge management utilization model in passive defense and the role of human resources as a common and major element، authors conclude that employing knowledge management plays an effective role in the success of passive defense. Therefore; they deal with the necessity of the combination of knowledge management and passive defense with the usage of above model to establish a system to save expenses، time، duplication and prevent damages along with the protection of experts'' knowledge and experience of organization along with the determination of a suitable security level.

Communication paths are one of the most important elements in increasing or decreasing the vulnerability in a city. The abundance of access routes has significant impacts on the vulnerability mitigation and the number of casualties. This research is intended to find a relation between hierarchy of street network and earthquake، by using existing data about vulnerability of urban streets for district 10 of Tehran from passive defense viewpoint. This research is intended to find a relation between hierarchy of street network and earthquake، by using existing data about vulnerability of urban streets for district 10 of Tehran from passive defense viewpoint. In principle، passive defense in cities and centers of gravity or vulnerable centers of cities has close relations andis considered as one of the important steps in planning passive defense measures، prioritizing and classifying the significance of centers of gravity based on qualitative and quantitative criteria. Since the managerial approach and method of countering danger in cities should be preventive but not reactive type، therefore، this article is intended to use a passive defense approach. The present research is of applied type and the approach governing this research is analytical descriptive. The method of information collection is mainly documentary and interview and also according to research type، matrix method for local conformity district 10 of Tehran municipality is used from passive defense viewpoint. Human vulnerability against earthquakes، based on population density of the district، dense construction and results obtained from user matrix and its resultant chart are of high level. Having conducted analyses based on user matrix method and assessment of pathways inside district 10 and the results shown by charts 1 and 9، we can realize the significance of the existing pathways in this district and we will study the passive defense principles in these pathways، as well.

A large number of bridges have been affected and damaged in the recent earthquakes. Among then skewed Highway bridges with their principal mode commonly as rotation of deck with large displacement at deck corners، cosiderably stand out. Therefore، the effect of presence of shear keys will be much clearer in this type of bridges. Lateral displacement of corners as well as deck rotation and seismic demand of external shear keys in skewed bridge versus straight bridge are investigated in this study. Dynamic behavior of this structures subjected to blast، and presentation of new design methods are very important in passive defense. Then dynamic behavior of the bridge subjected to three blast scenarios is monitored. To achieve this، a finite element model of an existing bridge structure with shear key، is developed in the structural analysis software Open System for Earthquakes Engineering Simulation (Open SEES). It is concluded that shear keys can dissipate energy of the deck and reduce deck rotation، in this type of bridges.

According to the experience and beliefs of many industrial experts، assembly is one of the most important parts of industrial centers. In recent years، the approach of many major successful industrial centers has been forming small cells based on the industrial assembly functions. Moreover، establishing such places necessitates high costs، therefore; taking the principles of architectural design of secure industrial spaces with assembly functions into consideration، it contributes not only to considerable added value at the time of production and encountering threats، but also it is considered as major requirement of vital and important industrial centers which requires serious provisions. This article is intended to study the principles of architectural design of secure industrial spaces against threats using an analytical and descriptive method and incorporating expert ideas and questionnaires، from passive defense perspectives with a critical and analytical view.

Today، following the continued growth of urban population and increasing natural hazards، strengthening the resiliency of cities is essential and in order to mitigate vulnerability، it should be taken into account as an important part of urban development projects. In this regard، this study has been developed with a descriptive-analytical methodaimed at prioritizing the organization of streets in terms of strengthening their resiliency to reduce vulnerability to natural hazards. In this study، part of the central city of Damghanhas been studied as an example. In this regard، criteria influencing theresiliency of streets based on conducted studies were extracted، and each of thestreets was scored based on these criteria. In the end، all streets were classified based on the total scores and the weighting of criteria، hence، prioritizing each street can be stated for the organizing process.

Providing power supplies for vital military centers in critical conditions is one of the important criteria of passive defense. Increasing power system reliability، resolving energy loss in peak hours and transmission lines congestion are the main purposes of Demand Response Programs (DRPs) development. DRPs have been designed to consider the consumers participation in power system operation. In this paper، both the spinning reserve and the demand side reserve، which is modeled as Emergency Demand Response Program (EDRP) and Time of Use (TOU) program، are taken into account as the operating reserve services. The two-stage stochastic Security Constrained Unit Commitment (SCUC) has been utilized to consider emergencies. The proposed model is applied to a sample power system which has some special costumers (such as militaries، basic industries، administrative and home). The results show that the DRPs have a great effect on power system security، increasing the whole system and its special costumers reliability.

Today، underground spaces are known as safe places for engineering and military applications. One of the hazards threatening these spaces is implosion. In this paper plastic zone produced by is implosion in Tuff Rock Mass has been investigated. This implosion is modeled by FLAC3D and the results have been compared with those of the PPV method. The results produced by numerical analyses show greater space boundary as plastic zone than space determined by PPV method. Therefore; it shows that numerical analysis gives more careful and safer structures.