Situation Threat Research Articles

Research on the influence of time delay on combat effectiveness of aircraft fleet

Aiming at the influence of time delay on the combat effectiveness of aircraft fleet under the command of airborne warning and control system (AWACS), the process of beyond visual range air combat under the command of AWACS is analyzed, as well as the time delay characteristics in the combat information flow. The air combat situation threat of the aircraft by enemy aircraft is represented by the weighted fusion of the speed threat, angle threat, distance threat, and height threat of the aircraft. The threat matrix is proposed to represent the threat to the whole aircraft fleet. The threat matrix consists of the situational threat between each of our aircraft and each of the enemy aircraft. And the threat matrix of both sides is calculated to obtain the pre-enemy launch probability of both sides. With the two-step adjudication method and capturing the target probability of the missile seeker under the influence of time delay, the probability and number of being destroyed are calculated, as well as the combat effectiveness ratio. The opposing forces of both sides are set, and the calculation results in Matlab are consistent with the actual ones, which verifies the rationality and validity of the model, and can provide a theoretical reference for determining the time accuracy of the air-based network.

Seasonal Respiratory Virus Circulation in a Tertiary Care Hospital in Greece

Background: The COVID-19 pandemic caused by the novel SARS-CoV-2 virus affected health care systems and public health worldwide dramatically. Several measures were applied in order to prevent or stop the rapid transmission of the virus and the subsequent disease, such as lockdowns, physical distancing, strictly hygiene, along with travel restrictions. Global population after vaccination programs against COVID-19 were carried out, is facing a “tripledemic” situation threat, with the co-existance of SARS-CoV-2, influenza and RSV. The aim of the present study was to evaluate the co-existence of SARS-CoV-2, influenza and RSV, as well as the correlation with gender, age, Cts and vaccination doses. Methods: A total of 302 patients were included in the study. All patients were admitted to the emergency department of General Hospital Nikea, Piraeus with common upper respiratory tract symptoms and were suspected for COVID-19 disease, between March to July 2022. Patients’ age, gender, vaccination doses, and results from RT-PCR detection for SARS-CoV-2, RSV and Influenza viruses were recorded. Results: 139 were male and 163 female, aged between 18-94 years. Out of the patients included in the study, 206 were vaccinated and 96 were not vaccinated. Among vaccinated patients 97 were male and 109 were female. A percentage of 3.3% had received one vaccination dose, 16.9% two and 47.7% three. Moreover, 88 patients presented infection symptoms; 81 patients had a positive rapid test result. We detected 15 cases of co-infection of SaRS-CoV-2 and RSV and only one case, of co-infection of SaRS-CoV-2 with influenza virus. Conclusions: The majority of patients admitted to the emergency department of GHNP with common upper respiratory tract clinical manifestations were female. A significantly lower rate of co-infection with SARS-CoV-2 and RSV was detected in patients having received 2 vaccination doses, compared to patients having received 3 out of 3 vaccination doses or up to 1 vaccination dose. Ct values for SARS-CoV-2 and RSV pathogens were between 10-17. Co-infection with SARS-CoV-2 and Influenza was detected in only 1 patient.

Air Combat Maneuver Decision Method Based on A3C Deep Reinforcement Learning

To solve the maneuvering decision problem in air combat of unmanned combat aircraft vehicles (UCAVs), in this paper, an autonomous maneuver decision method is proposed for a UCAV based on deep reinforcement learning. Firstly, the UCAV flight maneuver model and maneuver library of both opposing sides are established. Then, considering the different state transition effects of various actions when the pitch angles of the UCAVs are different, the 10 state variables including the pitch angle, are taken as the state space. Combined with the air combat situation threat assessment index model, a two-layer reward mechanism combining internal reward and sparse reward is designed as the evaluation basis of reinforcement learning. Then, the neural network model of the full connection layer is built according to an Asynchronous Advantage Actor–Critic (A3C) algorithm. In the way of multi-threading, our UCAV keeps interactively learning with the environment to train the model and gradually learns the optimal air combat maneuver countermeasure strategy, and guides our UCAV to conduct action selection. The algorithm reduces the correlation between samples through multi-threading asynchronous learning. Finally, the effectiveness and feasibility of the method are verified in three different air combat scenarios.

Research on security situation awareness method of power network Monitoring system based on data mining

In the traditional security situation awareness methods of power network monitoring systems, there are deviations in the analysis of different sample data sets, which affect the security situation threat value perception results of power network monitoring systems. Therefore, this paper designs a security situation awareness method for a power network monitoring system based on data mining. The identification structure of security situation elements is determined, the self-encoder is used for mapping, the security situation elements of the power network monitoring system are extracted according to the obtained parameter samples, and the security situation awareness model of the power network monitoring system is established. The RBF neural network is used for data mining of the monitoring system, and the design of the security situation awareness method of the power network monitoring system based on data mining is completed. The experimental results show that the recognition accuracy of the design method for samples with different threat levels is more than 90%. Compared with the traditional methods, the security situation awareness results obtained by the design method are closer to the expected output threat value.

Nudging physical distancing behaviors during the pandemic: a field experiment on passengers in the subway stations of shiraz, Iran

BackgroundThe possibility of the emergence of new pandemics necessitates further research into using simple strategies to promote social distancing behaviors in public. Most of the current evidence on effectiveness of physical distancing interventions is based on self-report and measure of intention which will not necessarily predict actual behavior.MethodsA field experimental study was conducted in the subway stations of Shiraz, Southern Iran. The interventions were based on intuitions from protection motivation theory and consisted of using environmental nudges to notify the passengers of the pandemic situation (threat appeal) and a verbal advice on keeping a safe physical distance as an effective method of protection against COVID-19 (coping message). Average physical distancing was estimated as the number of steps between two consecutive passengers and was compared between interventions (n = 1045) and the control (n = 855) groups.ResultsA total of 1900 people riding on subway escalators were directly observed during two intervention conditions and the control condition. Under either threat or coping-based interventions, passengers were two times more likely (OR 2.0, 95%CI 1.5–2.7, P < 0.001) to keep a physical distance of at least 1.2 m from the traveler in front compared with those who did receive no intervention. The Kruskal-Wallis test revealed that there was a significant improvement in physical distancing behaviors with coping advice compared with threat appeal and the control conditions (χ2 = 120.84, df = 2, p < 0.001).ConclusionsOur findings suggest that simple and inexpensive theory-based interventions can be used in crowded public spaces to promote physical distancing within the context of the pandemic.

Intensity of ecotoxicants’ accumulation in internal organs and milk of dairy cows in the North-West of Transurals

The work of the agrarian sector of the economy is impossible without deep awareness of the serious environmental situation threat of anthropogenic factors’ influence due to the increasing intensification system of processes in animal husbandry. In addition to understanding the processes occurring in connection with the increase in anthropogenic load, real-time information about the real situation in the agroecosystem is necessary. Forecast of decision-making, consequences of certain actions. Control and monitoring of changes in the environmental situation. Therefore, the current control and the real system for assessing the ecological situation is important for the correct ecological activity of the agrarian organization. The greatest ecotoxicants’ concentration is observed in the body of experimental animals, most of all in the respiratory and excretory organs. The minimum level of ecotoxicants was observed in muscle tissue, hence it is an environmentally friendly livestock product. The concentration of arsenic, mercury in the experiment is at the level of trace indicators. The level of ecotoxicants’ accumulation in drinking cow’s milk was established, the correlation between the pollutants’ level in the product and the location of agricultural production, season and production time was found.

Online classification of frequent behaviours based on multidimensional trajectories

In early warning surveillance domain, frequent behaviours could be mined from historical trajectories. Based on the mined frequent behaviours, online classification technology could be used to classify the continuously updated target trajectories. Online classification of frequent behaviours is of great significance for situation assessment, threat assessment and command decision. There are a lot of researches on trajectory classification. However, they cannot distinguish behaviours whose space position is similar but the moving speed and direction are quite different. The online classification performances of them are also not appropriate for early warning surveillance application. The authors propose a conformal multi-class classifier based on conformal predictor and propose a multi-factor non-conformity measure based on multidimensional trajectories firstly. Then, they present a sequential multi-factor Hausdorff nearest neighbour conformal multi-class classifier, which could online learn and classify frequent behaviours. Experiments in both simulated military scenario and realistic civilian scenario show the presented algorithm has a good performance to online classify frequent behaviours and would have a wide prospect in early warning surveillance systems.

Hybrid neural network in circulating fluidized bed boiler based on information fusion clustering control

Circulating fluidized bed boiler (CFBB) is regarded as a clean and highly efficient coal combustion technology, and recently, this combustion technology is rapidly developing. However, CFBB is a complicated control object with distributing parameters, nonlinearity, time varying, large time-delay, and strong coupling. Traditional control methods cannot obtain good control effect, which becomes one of the bottlenecks for its extending application. In this paper, we design a three-level ART2-BP–BP of data fusion—cluster control system based on methods of multi-sensor information fusion and cluster analysis. We complete data fusion from the data level, feature level, to the decision level. By this method, more complete description of the conditions is obtained, and appropriate control strategies according to each category are taken, describing behavioral characteristics in the process. Then, the potential situation threat in working boiler is estimated, and the concept of situation threat space is proposed. Results of simulation show that the control system in this paper is feasible and effective; in particular, the control system still has more satisfactory control effect in the case of a variety of sensor failures.

Technological safety and improvement of the normative base of anticorrosion protection of metallic building structures

We substantiate the rational choice of corrosion protection measures at the design stage. The necessity of estimation of reliability indicators by limiting states with regard for the requirements related to the corrosion resistance, durability, and maintainability is demonstrated. Using the developed approach, we analyze the corrosion risk as a state or situation (threat) in which the probability of losses increases. By using the corrosion risk criterion, one can economically substantiate requirements for the choice of design characteristics of primary and secondary protection. Expenses and possible risks are estimated by using the computational models of operational maintenance of objects of different purposes.

Based on Multi-Sensor Information Fusion Circulating Fluidized Bed Boiler Combustion Process Clustering Control Research

Abstract Over the decade, due to the fact that the global energy resources are in deadly shortage, much emphasis is put on the energy consumption in thermal power throughout the world. Following developed is Circulating Fluidized Bed Boiler (CFBB) in recent years, a kind of combustion boiler that can clean and desulfurize the coal efficiently in the combustion process.Circulating Fluidized Bed Boiler (CFBB) is a control object with features of time varying parameters, large delay, and multivariable control tightly coupled. Noticeably, many factors influence the combustion process. This paper designs a three level ART2-BP-BP of data fusion--fusion cluster control system based on methods of multi-sensor information fusion and cluster analysis. It completes data fusion from the data level, the feature level to the decision level. Especially, the concept of Situation Threat Space aiming at the potential threats in CFBB is presented. Results of simulation show that the control system in this paper is feasible and effective, in particular, the control system still has more satisfactory control effect in the case of a variety of sensor failures.

Storm Clouds and Silver Linings: Responding to Disruptive Innovations Through Cognitive Resilience

Incumbent firms facing disruptive business model innovations must decide whether to respond through inaction, resistance, adoption, or resilience. We focus on resilient responses to simultaneous perceived threat and opportunity by managers of small incumbent firms. Using cognitive framing arguments, we argue that risk experience moderates perceptions of opportunity, whereas perceived urgency moderates situation threat. We test our framework in the real estate brokerage context, where small incumbents face considerable challenges from disruptive business model innovations, such as discount brokers. Analysis of data from 126 real estate brokers broadly confirms our framework. We conclude with implications of our research for small business incumbents.

Fear, attachment and affiliation: The interaction of functional systems in 8‐ and 12‐month‐old infants

AbstractIn this research fear of strangers has been analysed as it interacts with attachment and affiliation, and in relation to developmental level, in conditions most similar to the natural situations where encounters with unfamiliar persons take place. A total of 30 infants and their mothers participated. The children were divided into two groups (8‐9 and 11‐12 months). Each infant was approached by two females, who, in turn, produced either of two natural sequences. Our results allowed us to confirm the universality of fear and its coexistence and interaction with attachment and affiliation. As far as the role that developmental level plays, it was noted that in the 12‐month‐old infants fear reactions were more intense than in the younger ones. Furthermore, the attachment system was more activated in the older group in the intrusive episodes, but when the threatening nature of the situation decreased, attachment was activated less in the 12‐month‐old group. Another difference was related to control resources. While in the younger infants we observed a tendency to control their own emotional state, the 12‐month‐old infants tried to gain control over the stranger. These results were interpreted by considering the adaptative value of an increase with age of the capacity to evaluate a situation's threat value, of attachment security, and of behavioural resources permitting some control over the stranger's behaviour.

Are life events which cause each other additive in their effects?

In a study in which life event data collected on 1060 people from Livingston New Town, life situations (i. e. events and/or long-term difficulties) which might have been causally linked were identified. Some of these causal chains were unequivocal. Given the occurrence of the first event, the occurrence of the second could be predicted with near certainty. Others were less definite; the situations were clearly linked but the second could not be definitely predicted from the first. Symptom scores (anxiety + depression) of people whose life situations were causally linked were compared to those of people with no linked situations. The comparison involved 167 matched pairs in which the number, degree of threat, and timing of life situations were equalised. Those with no linked situations tended to have higher symptom scores than matched subjects with linked situations, provided the earlier situations were at least moderately threatening. The effect was much stronger when the causal connections between situations were unequivocal. In the total sample the life situation threat scores of all such people were then modified, discounting where feasible all situations bar the latest one in the chain. Where two or more linked long-term difficulties were both still operative at the time of interview they were amalgamated and scored as one. The result was a highly significant gain in the symptom variance which could be explained by life events. The effect appeared to be to some extent applicable irrespective of the threat values of the situations making up the causal chain. However, there were slight indications that it might be stronger when a neutral or pleasant event terminates a threatening situation. It could not be explained by prior members of a causal chain tending to occur earlier in time or by a general tendency for non-additivity of effect to occur among people with many life situations in a short space of time.