فصلنامه پدافند غیرعامل
سال پنجم شماره 1 (پیاپی 17، بهار 1393)

Observing the "principle of dispersion" is one of the principles of passive defense. This principle can also be applied to IT services. Database outsourcing in an organization can contribute to "the principle of dispersion" in data storage for that organization. Presenting a suitable classification of the challenges of outsourcing will contribute to the identification of appropriate strategies to mitigate vulnerability against hostile threats and actions. In this paper, through investigating the architecture of database outsourcing, a new category of security challenges facing data outsourcing is presented that will eliminate shortcomings of previous category. This new classification can be helpful in better directing the future research.

Considering terrorist and hostile attacks against our homeland, investigating the structure performance against explosions and the phenomenon of advancing failure is of utmost importance. Therefore; structure hardening against explosions and the phenomenon of advancing destruction is one of the important issues in passive defense. This article deals with the attitude of steel structures with ordinary bending frame (SMRF) and the reinforced bending frame with back pulled cable (PTED) against advancing failure. In this regard, the alternate load path method (APM) has been used based on the DOD and GSA Directive. According to this method, the structure frame, after the elimination of the pillars of the first floor, should behave in such a manner that the first failure does not expand. Therefore; modeling is performed in the SAP2000 V15 software. To analyze the structures, non-linear static method is employed. The non-linear static analysis results of the software regarding the three-storey structure are compared with those of the experimental results of researchers showing a good compatibility. The performed analysis indicates that although the vertical envelope curve of the ordinary bending frame has more resistance against advancing destruction, the performance of the bending frame PTED performs better against big deformities caused by advancing destruction. The bending frame PTED, with the help of cables and energy dampers, prevents plastic deformities in pillars and shores and the structure collapse, as well. Moreover, the energy in the dampers is consumed and if necessary, will be replaced.

One of the most important parts in densely populated places is staircases that cause irreparable damage if they are ignored. A staircase is a place for entrance and exit. In crisis time, it is a way for running and assistance. Therefore; paying careful attention to the design of staircases can reduce any possible damage. In this article, the necessities of passive in the design of staircases have been presented which is intended to take the design regulations to deal with crisis and consequently to reduce fatalities and collateral damage. This article initially introduces the load members of a concrete staircase. Then, in an explosion analysis using the ABAQUS finite element model, the layout and adequacy of bearing members has been evaluated. The assumptions in this research are made based on external type explosion and moreover, the staircase has been analyzed independent of the structure against blast load. The effects of surrounding walls of the staircase box has been neglected because of low resistance against explosion loading. The results show that the minimum damage will be obtained if the staircase is located at center of building. In addition, increasing the thickness of concrete slab in connection with zone between ramp slab and landing slab can reduce deflection of staircase.

Software security is concerned with methods of producing secure software. Concepts that are important to software security contain system risks management, programming language, platform, software audits, designing security and security tests. In other words, compliance with the security provisions in the production process can be considered an issue of passive defense in the field of software. In most cases, the programming mistakes that are easily avoided, lead to exploitable vulnerabilities in software. Reviews and analyses performed on thousand reported vulnerabilities, suggest that most vulnerabilities arise from a small number of common programming errors. We know that as soon as a vulnerability is discovered, it is easier and cheaper to fix. Application of the safe software development lifecycle, which investigates the security in each step of development to identify early potential vulnerabilities in each stage of development for the early identification of potential vulnerabilities is of utmost importance in securing software.Therefore, developers should understand secure coding techniques in order to reduce security errors and appropriate development of secure applications. This article suggests guidelines for secure coding.

Reinforced soil structures are one of the most usual means of passive defense in the protection of personnel and property from accidental explosion of stored explosives and terrorist bomb attacks. Reinforced Soil (RS) walls are good blast energy-absorbing structures due to inherent properties of the backfill soil materials. In this study, in addition to general comparison of different kinds of reinforced soil walls, numerical modelling has been done for walls with different distance from the explosion. Blast induced pressures amplitudes have been evaluated through nonlinear dynamic analysis and results have been compared with full-scale blast trials. One of the key findings of this study is investigating the reason of different response of walls in close range blasts and far field blast. Walls showed a localized failure mechanism occurred in close range blasts in contrast to general behavior in far field blasts.

Nowadays, due to hostile threats, most critical and important structures are built underground. Being underground and the camouflage and concealment of these structures impose certain limitations and conditions on their mechanical installations that are never considered for other buildings. The appropriate design of mechanical installations of underground structures with the passive defense approach for normal and critical conditions are so indispensable and sensitive that in case they are designed inappropriately, not only their vulnerability will not reduce but also an underground structure can be turned to a mass cemetery in this regard. Because these installations are easily detectable and vulnerable and also the most important part of an underground structure. This article intends to transfer the experience of its writer regarding design considerations of ventilation and cold and warm facilities of underground structures with the passive defense approach, particularly the camouflage and concealment issues. The ordinary methods of air conditioning and the advantages and disadvantages of each are investigated and then taking the whole technical and economical and passive defense issues into considerations, the appropriate cold and warm and ventilation system of a typical underground structure is suggested. Finally, the executive solutions to prevent the entrance of smoke and contamination to the personnel assembly area and also solutions for the camouflage and concealment of fans and also exhaust air shafts, are explained. The said executive solutions have been already employed in various projects and their performance has been approved which due to their confidentiality nature, their technical details are excluded.