فصلنامه پدافند غیرعامل
سال دوازدهم شماره 1 (پیاپی 45، بهار 1400)

Vulnerability and damage assessment, planning for awareness, and reducing risk before an earthquake are essential. As the city of Yasooj is located in a high-risk area, the occurrence of a major earthquake in this city will cause lots of damages, and therefore hospitals are classified as the most important buildings. It is very important to respect the principles of passive defense in the construction of hospitals, as they are referred to, for helping the injured during earthquakes. Therefore, this research has been conducted by descriptive-analytical research method and with the aim of evaluating and comparing the vulnerability of Yasooj hospitals by two methods passive defense and ATC (Applied Technology Council). The results of this study showed that according to the ATC method, Shohadyeh Gomnam hospital (S = 2), Imam Sajjad hospital       (S = 2.3) and Shahid Jalilfar hospital (S = 5.5) were the most vulnerable, respectively. According to the scores of the final structural evaluation of these hospitals against seismic vulnerabilities, the Shahid Jalil, Imam Sajjad and Shohadyeh Gomnam hospitals were classified as having complete, acceptable and unacceptable safety (possibly dangerous), respectively. Also, according to the approach of passive defense, in the order of rising vulnerability, Imam Sajjad hospital (A_T=8.01), Shahid Jalilf hospital (A_T=7.26) and Shohadyeh Gomnam (A_T=6.22) were the most vulnerable. Finally, based on these two methods, the vulnerabilities of Yasooj city hospitals were compared and it was founded that Shahid Jalil, Shohadyeh Gomnam and Imam Sajjad hospitals have the least vulnerability, respectively.

Today, the design of an intelligent receiver is essential for identification and blind detection of signals in the communications that are based on the burst signal. The first and most important step in this type of receiver detection, is signal presence detection and determination of the start and end points of the bursts for the purpose of extracting information. In this paper, a new method for blind detection of the burst signal is provided. In the proposed method, the beginning and end of bursts, which are actually the edges of the signal, are obtained by wavelet transform. Dice similarity criterion, burst error criterion, silence time error criterion and total error criterion are applied to investigate the detector performance. For long bursts taken as an example, the results of the wavelet transform detector simulation in the Gaussian channel, indicate that in the signal to noise ratio of -2 dB, the dice coefficient is around 0/9768 which shows the proper performance of the proposed method compared to the existing methods in this field.

After any nuclear disaster, radioactive materials are released into the environment, polluting the environment, livestock and livestock products. These substances can enter the human body in the natural cycle through the food chain, a process which must be avoided. To this end, in this study, while examining the release of nuclear materials and the contamination of farm animals and livestock products after nuclear accidents in the world, especially the Chernobyl (1986) and Fukushima (2011) disasters, the ways to prevent or eliminate the induced contaminations were also examined. Due to the importance of 3 radionuclides; radio-cesium, radio-iodine and     radio- strontium, their cycles in nature were studied. This is a qualitative study based on retrospective time dimension with an applied purpose. Results of this study demonstrated that after exposure to radioactive substances animals have shown side effects such as immune deficiency, lowered body temperature, heart failure, partial atrophy or complete destruction of the thyroid gland, liver damage and eventually death. In the event of a nuclear disaster, it is essential that effective measures be taken as soon as possible to reduce the transmission of radioactive contamination to the food chain. Radiological monitoring of livestock products, prohibition of the use of contaminated food in livestock and poultry feed, and processing of food prepared from livestock products, are among the defense methods that can be used to reduce the transfer of radioactive materials from livestock products to humans. The results of this study also indicated that, exploration of radionuclide transport pathways to farm animals and their products can lead to the design of countermeasures that have the highest degree of efficacy and can be implemented in the shortest possible time to avoid maximum contamination.

The purpose of this study is to evaluate the indicators of passive defense in the villages of Kermanshah province. In this research, an attempt has been made to answer the following questions: What are the most important factors affecting the vulnerability of villages in Kermanshah province? Which goals are more important and sensitive? If the targets are attacked, how can we assess the ability to repair and revitalize those targets? The statistical population of the study consists of 434 border and non-border villages with more than 50 households in Kermanshah province, in which the Guidance Plan has been implemented. The sample size includes 20 selected villages in which the physical progress of the Guidance Plan has been reported at the highest rate. This research is of the applied type and has been done by the descriptive method. The results of the study show that military centers are the most sensitive in terms of all the 7 criteria used in the analysis. Therefore, in locating these places in rural areas, it is necessary to pay basic attention to following issues. First, the principles of passive defense such as camouflage, concealment, and deception should be considered in their placement, and secondly, these establishments should be placed far away from rural areas to minimize their vulnerability during attack.

Due to Iran's strategic position and the political situation in the West, human dangers such as military aggression always threaten the borders of the Islamic Republic of Iran. Considering this issue and the successive threats made by the West and of course, the experiences of the forty years following the Islamic Revolution (attacks on cities and civilians) have led to the appreciation of the need to implement the principles of passive defense in all dimensions. In the event of any potential danger, it is vital to be prepared to react quickly and minimize human and financial losses. Cities have become more vulnerable to accidentsdue to the growth of urbanization and the expansion of cities. The purpose of this study is to locate and construct multi-purpose urban shelters in Bojnourd in order to reduce human casualties.This research is of the descriptive-analytical type in which documents and library resources are used to explain the concepts and extract the necessary criteria for urban planning. Then in order to locate multi-purpose urban shelters using AHP model, the indicators are prioritized using the Weighted Overlay function of the GIS software. The output-related map criteria have been obtained for each criterion, and by overlapping different maps, we have achieved 3 multi-purpose urban shelters for Bojnourd city.The results indicate that the Shahid Square (0.6079) and the Friday prayer mosque (0.3406) can be used as the most suitable shelters for emergencies. It should also be noted that the city park (0.0456) can be used as a reservation in case of space inadequacy in the two mentioned places.

After the occurrence of natural disasters such as earthquakes, the engineers' first action is the initial safety assessment and determination of the performance grade of the structures. Existing methods, including eye examinations, are prone to many errors. These types of methods, depend on the level of knowledge, experience, and judgment of individuals. Therefore, attempts have been made to use methods to quantify fault detection. In each of these methods, it is necessary to use an indicator to measure failures. Another point to keep in mind is that new computer science methods have made it possible to use image processing tools to measure breakdown indices. In this study, after examining the types of shear wall failure, the crack width criterion has been introduced as an indicator to evaluate the failure. By examining image processing methods, a suitable method for evaluating shear wall failure has been presented. This study's results can be used to assess the failure of shear walls and determine their damage.

Due to its special political standing and geographical location, the land of Iran has always witnessed many natural and unnatural disasters throughout history. Therefore, the theoretical and practical position of passive defense in the face of crises is very important in this region. The location of military centers can play a significant role in passive defense naturally if it is done based on location studies and land management principles. This study is a practical research with descriptive-analytical and survey methods. In this study, in order to evaluate the factors affecting the location of military centers from the perspective of passive defense in the northwest region, the following restrictions have been used: climatic parameters (including the frequency of occurrence of frost, rain, snow, storm, dust and fog and also the wind speed), the geomorphologic and geologic parameters (the land slope and the land inclination direction , height and lithology), the parameters of accessibility of man-made centers (the distance from urban points and the distance from reservoir dams), infrastructure parameters (the distance from communication routes, the distance from airports and the distance from air corridors) and hydrological specifications (such as the distance from waterways). Then, using AHP analytical method, each of the studied parameters was given a numerical weight due to their importance in passive defense. To calculate the weight of indicators and the importance of the coefficient of each criterion, the process of hierarchical and software analysis of Expert Choice software was used. Finally, by modeling them in the GIS environment and also by using the overlap method, all effective layers in passive defense were combined. The results showed that very limited and scattered areas of the region under study, have the potential of housing military and civilian centers from the passive defense perspective.

Given the essential role of individual trenches in the survival and mission accomplishment of insider forces, especially in the plains, it is obvious that the enemy uses a variety of aerial and space sensors for their detection and identification. Imaging cameras are one of the main systems for detecting targets, especially at night. The main agent that causes the detection of a trench in thermal images is the thermal anomaly in its opening with respect to the surrounding environment. This study intends to use field observations and visual assessment methods to investigate the possibility of identifying fighters stationed in foxhole trenches and to provide measures and considerations to prevent the detection of foxhole trenches in plain areas. For this purpose, 36 scenarios in different positions namely: person standing next to the trench, person standing in the trench and person sitting in the trench, two different times, bright and dark days at different distances, are considered. Based on the experimental results obtained, it is possible to detect foxhole trenches without camouflage in plain areas at close range. Also, the best type of camouflage is the use of dry and lifeless plants related to the area.