فصلنامه پدافند غیرعامل
سال چهاردهم شماره 4 (پیاپی 56، زمستان 1402)

Throughout history, territories have always been exposed to natural hazards (earthquakes, floods, etc.) and human hazards (war) and have caused a lot of human and financial losses. Therefore, the importance of passive defense before and after the crisis in order to control and reduce the damages is undeniable. Therefore, the purpose of the current research is to evaluate the use of urban land with an emphasis on passive defense, which was carried out in Ardabil city as a case study. The research method is analytical-descriptive and SWOT model is used to determine the strategies. The findings from the implementation of the mentioned model show that the highest weighted score is related to threat points with a value of 3.64 and the lowest weighted score is related to strengths with a value of 2.87. be The research results indicate that land use planning in Ardabil city is closer to defensive strategies in terms of passive defense, and Ardabil city lacks comprehensive planning in the field of passive defense. Considering that the highest weight score obtained is related to the external factor (threat) of land use in Ardabil city, it is necessary to take necessary measures to solve them.

Humans have always sought a solution to overcome the phenomenon of darkness and produce light in dark or low light environments. They have overcome this problem by inventing a variety of lights and lamps. In current lighting systems, the lighting source is located in the ceiling, which has advantages such as a relatively uniform distribution of light intensity in the entire environment centered on the location of the source and, of course, disadvantages such as the need for wiring in the ceiling. In places such as tunnels, buildings with high ceilings, very high arches, and such things, in addition to the high cost of wiring in the roof, if there is a need to repair or replace the lighting source, in addition to the great difficulty and risks, an additional fee should be considered for this purpose. In addition, the absence of a wire carrying electricity in the ceiling is one of the requirements in some places. In order to increase the safety of people and equipment and significantly reduce the cost, as well as not using the wire carrying electricity in the roof of some tunnels or buildings in order to comply with the principles of passive defense, a new lighting system has been proposed that uses LED light sources as lighting sources. The use of a collimated optical element, along with the use of a  reflector-diffuser system, in addition to removing the electricity transmission wire from the ceiling and the possibility of easy repair or replacement of the light source, also provide the required lighting for that place. The results of the experimental setup conducted using two different geometries for the reflector-diffuser system indicate that the use of the proposed method not only does not reduce the measurement lux of the light scattered in the environment but also increases the brightness to a small value.

The ever-increasing development of telecommunications has made secure transmission one of the most important issues today. Since there is a high hiding capacity in the image, the use of image encryption is much more common than other methods of encryption. This article uses the covert imaging technique with the wavelet transform method, and the results show that this method has high resistance. For the analysis of hidden images, an algorithmic wavelet transform method using matrix features (GLCM) and co-occurrence vectors (DCL) is presented. After checking these values in the original and cover images, the different features between these images are extracted and used to train the multilayer neural network (MLP). The classification stage has been performed using the layers of this neural network and the proposed algorithm has been tested for a database of 200 standard images (Casia-Iris). The detection accuracy of 90% of the hidden images in the proposed method shows the superiority of this hidden mining method over other methods.

Passive Defense in a country like Iran can be used to plan and create barriers to deter enemy attacks and minimize vulnerabilities in cities and in line with the issues of sustainable development and security of cities, communities and important urban infrastructures. In this regard, the present research has dealt with the zoning of Urmia city with a defense-oriented approach. The type of research is based on applied goals and a descriptive analytical nature. For this purpose, first by studying the sources related to the approach of defense and non-active defense, the number of 6 criteria and 22 sub-criteria have been selected according to the availability of information for the city of Urmia. The index weights were calculated using the ANP network analysis process in the Super Decision software. Then, by entering the indicators into the GIS environment and implementing them on the city, maps related to each indicator were produced; From the integration of sub-criteria maps related to each criterion, a zoning map was obtained based on that specific criterion, and finally, from the integration of these 6 maps, the final zoning of the defense area of Urmia city was obtained. The results of the criteria overlap map show that about 17% of the city is in the high vulnerability zone, 26% in the medium vulnerability zone and 55% in the low vulnerability zone. In the following, the SAW decision-making model was used to rank the regions, which indicates the vulnerability of regions 2 and 4 more than regions 3 and 1.

One of the most important challenges of nuclear accidents is the release and suspension of radioactive particles in the atmosphere. Knowing the behavior of these particles in the atmosphere will optimize management and subsequent decisions of unforeseen events. Using natural radioactive particles as environmental tracers to study atmospheric pollutants is one of the key and important studies in conducting atmospheric research. In order to determine the concentration of Pb-210, Bi-210 and Po-210 radionuclides, as well as to estimate the residence time of radioactive particles, sampling was done on a monthly basis from November 1400 to October 1401 in Tehran. The samples were taken by a high volume sampling pump with an average flow rate of 1.5 cubic meters per minute with a time interval of 6 to 12 hours and were prepared and counted in the Atomic Energy Organization. The results of the monthly average concentration of radionuclides show that the highest measured value for Pb-210 was 1.25 mBq/m3 in October. The average annual concentration for this parameter was around 0.89 mBq/m3, and its lowest value was recorded in April with a value of 0.42 mBq/m3. The results showed a relative increase in the concentration of this variable for April and May and a relative decrease for September and December. The average measured concentration for the variable  Po-210 in the whole period was about 0.058 mBq/m3. Also, 0.095 mBq/m3 in December is the highest concentration and 0.032 mBq/m3 in January is the lowest value measured for this radionuclide. The same trend was observed for Bi-210 with an overall average of 0.42 mBq/m3 for the period under review. The highest and lowest values measured for this radionuclide in the entire study period were 0.85 and 0.18 mBq/m3, respectively. According to the obtained results, based on Pb-210/Po-210, the average residence time of suspended particles was estimated to be 20.1 days. Based on this, July with an average of 22.5 days and January with an average of 17.8 days were estimated as the maximum and minimum length of stay measured in this research work. The obtained results can help in formulating the release and inhalation scenarios of radioactive particles caused by nuclear accidents.

Since the distant past, environmental hazards (natural and human) have been integral parts of human life. Deep knowledge of areas and territories and considering the necessary arrangements helps us in facing risks. But the most important factor that leads to a crisis when natural and human disasters occur is the physical vulnerability of buildings. Vulnerability of urban settlements, defenseless spaces, unsafe neighborhoods, cities with wrong architecture, all of them are factors that threaten urban and social security. On the urban scale, passive defense is a strategy to reduce vulnerability and increase resilience against both natural and man-made hazards. Therefore, the purpose of this research is to evaluate the vulnerability of the houses in Mahabad city from the point of view of non-active defense. The type of applied research and its method is descriptive-analytical. GIS and Expert choice software were used for data analysis. The findings of the research show that after the pairwise comparison of the research indicators with the AHP model, the building quality index with a weight of 0.137. It has the most points. and indicators of building life and unusual habitation and hazardous uses respectively 0.112, 0.11 and 0.101 is placed in the second, third, and fourth places, and at the end, the slope of the land and the width of the roads are at the 0.022 The irregular geometry of the urban fabric of Mahabad, the natural growth of the city, the existence of informal settlements and old and worn-out fabric in the central part of the city, the presence of residential plots with a smaller area in the southern and central fabric of the city, have made possible the vulnerable areas of the urban fabric and in In the event of natural and human crises, these tissues will be severely damaged and will cause a lot of financial and human losses.

One of the most obvious aspects of successful management and planning during the imposed war was the management of aid to the wounded in the form of establishing military field hospitals with passive defense approaches. So that the aforementioned action was developed from creating a tent or a roofed frame for relief at the beginning of the war to the construction of field hospitals in terms of passive defense requirements. In this way, the average duration of sending war wounded during the holy defense period in some fronts of the battle of right against falsehood to medical centers was reduced to less than one hour at the end of the imposed war, and by complying with the requirements of passive defense. Various factors are effective in the construction and establishment of a field hospital, which can lead to the improvement of the hospital's performance and reduce the risks of its construction and establishment while meeting the requirements of passive defense. Identifying these factors in the form of a scientific model during the occurrence of civilian crises in the construction and establishment of a civilian field hospital with a passive defense approach is also of great importance. The current research was conducted to identify the relationship between these factors to facilitate the management and provision of services to the wounded during the war and possible crises with the approach of passive defense. For this purpose, a main hypothesis and nine sub-hypotheses were designed and tested. This research is applied in terms of purpose and descriptive correlation in terms of method, in which exploratory structural equations were used. The statistical population includes military-scientific experts, 17 of whom were selected by purposeful sampling and the Delphi method until theoretical saturation was reached. The data collection tool is a structured interview method and a researcher-made questionnaire consisting of six dimensions, 11 factors, and 66 measures. Confirmatory factor analysis and PLS software were used to test the hypotheses. The results of the measurement model criteria (measurement reliability criteria, measurement model reliability, and divergence convergence of the model constructs) as well as the structural model criteria (determination coefficient criteria and model prediction suitability) indicate the optimal fit of the proposed model. Also, based on the t-value results, the main hypothesis and all sub-hypotheses were confirmed. The results indicate the direct effect of the "quality of management and command of the field hospital" dimension on the dimensions of "providing financial resources for providing specialized identification and treatment equipment", "providing general and specialized infrastructure of the field hospital" as well as "providing human resources of the field hospital". Of course, the "field hospital management and command quality" dimension has the greatest impact on the "field hospital treatment quality" and "field hospital readiness and support quality" dimensions. Also, the results showed that in addition to the dimension of "field hospital management and command quality" directly, positively, and significantly affects the dimensions of "providing general and specialized field hospital infrastructure" as well as "providing field hospital human resources"; The dimension of "providing financial resources for the provision of specialized identification and treatment equipment" also plays a full mediating role in these two relationships.

Determining effective indicators in the safety and health of sports facilities is very effective and important in improving the health of human resources/ The main goal of this research is to identify and evaluate the indicators that affect the safety and health of sports venues in Tehran/ The research method is practical in terms of purpose and descriptive-survey in terms of implementation/ Indoor multi-purpose halls (both training, competition, urban and   multi-purpose) as well as all indoor swimming pools were evaluated in the field and sports facilities analysis section in the number of 212 cases/ The statistical population in this research was the referents, executive agents and managers of sports fields and venues (130 people) and the sample size was 97 people using Morgan's table/ A researcher-made questionnaire with 86 indicators in 5 components was designed and distributed among experts/ The findings show that index A4 (safety of protection and unbreakable windows of windows overlooking the parking lot and warehouse) with an average of 4/05 in the safety component of entrances, fields and sports facilities, index B42 (safety of the corridor between seats) with an average of 3/71 The safety component of spectators' stands and restrooms, index C60 (safety of protective bars in buildings and places) with an average of 3/83 in the safety component of facilities and equipment, in the health component of entrances, fiDetermining effective indicators in the safety and health of sports facilities is very effective and important in improving the health of human resources/ The main goal of this research is to identify and evaluate the indicators that affect the safety and health of sports venues in Tehran/ The research method is practical in terms of purpose and descriptive-survey in terms of implementation/ Indoor multi-purpose halls (both training, competition, urban and multi-purpose) as well as all indoor swimming pools were evaluated in the field and sports facilities analysis section in the number of 212 cases/ The statistical population in this research was the referents, executive agents and managers of sports fields and venues (130 people) and the sample size was 97 people using Morgan's table/ A researcher-made questionnaire with 86 indicators in 5 components was designed and distributed among experts/ The findings show that index A4 (safety of protection and unbreakable windows of windows overlooking the parking lot and warehouse) with an average of 4/05 in the safety component of entrances, fields and sports facilities, index B42 (safety of the corridor between seats) with an average of 3/71 The safety component of spectators' stands and restrooms, index C60 (safety of protective bars in buildings and places) with an average of 3/83 in the safety component of facilities and equipment, in the health component of entrances, fields and sports facilities, index D69 (buffet hygiene) and warehouses) with an average of 3/79 in the hygiene component of entrances, fields and sports facilities and the E81 index (hygiene of drinking facilities) with an average of 3/26 in the hygiene component of the spectators' stands and toilets are the most important in improving safety and They have health and sports facilities/ Identifying and prioritizing the effective indicators in planning to improve the safety and health of sports facilities helps a lot/elds and sports facilities, index D69 (buffet hygiene) and warehouses) with an average of 3/79 in the hygiene component of entrances, fields and sports facilities and the E81 index (hygiene of drinking facilities) with an average of 3/26 in the hygiene component of the spectators' stands and toilets are the most important in improving safety and They have health and sports facilities/ Identifying and prioritizing the effective indicators in planning to improve the safety and health of sports facilities helps a lot.

In the new wars, which are carried out using advanced smart equipment and the targets are targeted point by point, The key points and goals that play a key role in the network of activities of the country are among the first goals. Since a significant part of these points are located inside the cities, the cities and especially the cities of the border provinces are also attacked. Due to its strategic position, the city of Dezful is always known as a target of attack by the enemy, and this issue is a warning about the instability of the city's structure. Also, considering the obvious characteristics of attack and support during the eight years of war, the need to explain, prepare the principles and requirements of passive defense for the vulnerability of the defense of this city, has made passive defense unavoidable. In addition to paying attention to the form, texture and construction of the city, the use of urban land, communication networks and urban infrastructures, passive defense has emphasized on locating the vital uses of the city. The storage of essential items is one of the vital uses of the city, which plays an important role in normalizing the situation after the crisis. Therefore, it is necessary to choose a suitable place for building, storing food and its optimal operation during a crisis. By using the principles and criteria of choosing a suitable location, the consequences of the enemy's attack on this site can be reduced to a large extent. In order to achieve the objectives of the research, the selected indicators affecting the location of the warehouse of essential items were extracted based on the passive defense approach for the dynamic population; . Therefore, five criteria 1) spatial, physical, 2) economic, 3) demographic, 4) security and defense and 5) natural, geographical and environmental were determined as effective criteria for the location of warehouses of essential items, a total of 22 indicators affecting location identified and using the hierarchical analysis process of AHP, their relative weight has been calculated And the GIS environment was used to prepare the map. After performing mathematical calculations, the highest amount of importance coefficient was assigned to the sub-criterion of access to communication network (0/155) and the lowest amount related to climatic conditions (0/015). Based on the application of the coefficients of the importance of the criteria and by using the overlap of the obtained spatial information maps, areas for the establishment of warehouses of essential items were zoned in Dezful city based on the range from completely suitable to completely unsuitable. Completely suitable and suitable have covered the area of 7 and 32% of the region, respectively. The results show that these places are mainly in the eastern and southeastern half of the city, including Farhang Shahr, Baharan, Payam Avaran, Negar, Taleghani, Modares, Moqavemat, and sevom Shaaban Koy, as well as parts of the streets of Ferdowsi and Imam Khomeini are located in the north.

cloud computing has revolutionized internet service with its advent. in cloud computing, security is the most important goal and the main requirement of a system. as cloud computing develops, a set of security problems appears. security problems are a strong obstacle to the adaptation of users to cloud computing systems. cloud security is becoming a key distinction and competitive advantage between cloud providers. this paper presents some cloud computing systems and analyzes the problem of cloud computing and its strategy with regard to the concepts and features of cloud computing. this paper tries to provide a comprehensive overview of cloud computing security and some of the key research challenges of cloud computing security. in this paper, the latest and most important cloud security issues such as data security, data secrecy, program security and challenges, attacks and solutions to deal with them with the development of cloud computing have been discussed. in the end, special security issues including the identity of access credit, development of insecure software, and third- party sources were investigated.

Hiding military equipment is one of the essential factors in establishing military superiority. Nowadays, most of the military devices, from night vision cameras to cameras mounted on military weapons, are equipped with infrared cameras. By using the temperature emitted from the objects, they can be identified in different situations, including absolute darkness. The multiple capabilities of these cameras in monitoring the other party's military capabilities have made camouflage technologies in this field more important, so that the development and research of new infrared camouflage methods and thermal cameras have become the focus of strategic development of countries around the world. This paper is a review paper in the field of infrared cameras, which is not similar in any other reference, and with a comprehensive view, while explaining the applications and principles of operation of infrared systems, it examines various methods of countermeasure with this type of camera. Also, at the end of the paper, a comprehensive classification of methods to countermeasure with this type of camera is presented.