Situation Awareness System Research Articles

An ontological framework for situation-aware access control of software services

Situation-aware applications need to capture relevant context information and user intention or purpose, to provide situation-specific access to software services. As such, a situation-aware access control approach coupled with purpose-oriented information is of critical importance. However, modelling purpose-oriented situations is a challenging task. Existing modelling approaches for situation-aware systems are not adequate to express purpose-oriented situations. Furthermore, existing context/situation-aware access control approaches are highly domain-specific and do not consider purpose-oriented information. In this paper we consider purpose-oriented situations rather than conventional situations (e.g., user׳s state) in proposing a generic situation-aware access control framework for software services. We take situation to mean the states of the entities and their relationships that are relevant to the purpose of a resource access request. Our framework includes a situation model specific to access control, identifying the relevant purpose-oriented situation information. Using the situation model, the policy model of the framework provides support for specifying and enforcing situation-aware access control policies. A software prototype has been developed to demonstrate the practical applicability of the framework. In addition, we demonstrate the general applicability of our framework through two case studies from different domains. Experiments are conducted to quantify the performance overhead of providing such situation-aware access control for software services.

Security in space: Should space traffic management also concern payloads management?

Significant initiatives on space traffic management have been recently taken, essentially by developing principles of outer space transparency and confidence building measures (TCBM) beneficial to a safer conduct of space activities. The need for improved practices in space traffic management is a consequence of the increasing number of space-faring nations allowing for more types of missions, growing number of space debris, new private entrants, and rising space content in running critical national infrastructures, to name a few. These expanding space activities underscore the society's dependency on space systems and its vulnerability, calling for an improved long-term sustainability of outer space activities. But the lack of information on the nature of some space payloads and their associated missions introduce a persistent flaw in succeeding to achieve a long thought stable and safer space environment. Indeed this noticeable weakness in the mentioned initiatives is not taken into account at this stage. To overcome this difficulty, a space situational awareness system (SSAS) based on a multinational organization, or under the purview of a UN steered agency, is proposed. It could be implemented promptly, provided there is a shared political will and a recognized urgent need to do so by major space-faring nations gauging their long-term interest while there is still time. The space deterrence postures by dominant space powers that have been identified during the past ten years, or so, argues in favour of broadening as soon as possible the scope of the current TCBM.

Distributed situation awareness in complex collaborative systems: A field study of bridge operations on platform supply vessels.

This study provides empirical data about shipboard practices in bridge operations on board a selection of platform supply vessels (PSVs). Using the theoretical concept of distributed situation awareness, the study examines how situation awareness (SA)-related information is distributed and coordinated at the bridge. This study thus favours a systems approach to studying SA, viewing it not as a phenomenon that solely happens in each individual's mind but rather as something that happens between individuals and the tools that they use in a collaborative system. Thus, this study adds to our understanding of SA as a distributed phenomenon. Data were collected in four field studies that lasted between 8 and 14 days on PSVs that operate on the Norwegian continental shelf and UK continental shelf. The study revealed pronounced variations in shipboard practices regarding how the bridge team attended to operational planning, communication procedures, and distracting/interrupting factors during operations. These findings shed new light on how SA might decrease in bridge teams during platform supply operations. The findings from this study emphasize the need to assess and establish shipboard practices that support the bridge teams' SA needs in day-to-day operations.Practitioner pointsProvides insights into how shipboard practices that are relevant to planning, communication and the occurrence of distracting/interrupting factors are realized in bridge operations.Notes possible areas for improvement to enhance distributed SA in bridge operations.

Situation awareness systems, states and processes: a holistic framework

This paper argues that state, system, and process descriptions of situation awareness (SA) are interdependent. Based on SA research from the last 30 years, the paper proposes a holistic SA framework. SA states emerge from processes of exploring situations through SA systems. Reflecting research on safety II (resilience), in describing SA states, the framework distinguishes frames (what situations are considered) from implications (regarding the situations) of objects on and of an event horizon. The paper describes and discusses SA system and process dependencies on SA states. It also describes SA system components as mediators and catalysts for SA, SA system properties (e.g. buffering SA), and dynamic SA system formation. Based on an analysis of four enactments of Air Traffic Control situations, the paper argues that what is domain-characteristic may not characterise all situations in a domain. The SA field could thus benefit from incrementally refining a nuanced cross-domain framework.

A Big Data Architecture Design for Smart Grids Based on Random Matrix Theory

Model-based analysis tools, built on assumptions and simplifications, are difficult to handle smart grids with data characterized by volume, velocity, variety, and veracity (i.e., 4Vs data). This paper, using random matrix theory (RMT), motivates data-driven tools to perceive the complex grids in high-dimension; meanwhile, an architecture with detailed procedures is proposed. In algorithm perspective, the architecture performs a high-dimensional analysis and compares the findings with RMT predictions to conduct anomaly detections. Mean spectral radius (MSR), as a statistical indicator, is defined to reflect the correlations of system data in different dimensions. In management mode perspective, a group-work mode is discussed for smart grids operation. This mode breaks through regional limitations for energy flows and data flows, and makes advanced big data analyses possible. For a specific large-scale zone-dividing system with multiple connected utilities, each site, operating under the group-work mode, is able to work out the regional MSR only with its own measured/simulated data. The large-scale interconnected system, in this way, is naturally decoupled from statistical parameters perspective, rather than from engineering models perspective. Furthermore, a comparative analysis of these distributed MSRs, even with imperceptible different raw data, will produce a contour line to detect the event and locate the source. It demonstrates that the architecture is compatible with the block calculation only using the regional small database; beyond that, this architecture, as a data-driven solution, is sensitive to system situation awareness, and practical for real large-scale interconnected systems. Five case studies and their visualizations validate the designed architecture in various fields of power systems. To our best knowledge, this paper is the first attempt to apply big data technology into smart grids.

Let the Reader Decide

In science and engineering, there is a natural rise and fall of paradigms as progress is made. In this way a new paradigm becomes more established until it gives way to new developments. We think it is legitimate to raise concerns over the status quo and propose new paradigms. This is how science moves forward, but we do recognize that paradigm owners tend to resist change. We contend that distributed situation awareness presents a new paradigm for analyzing and explaining situation awareness in systems, and there is a groundswell of studies that are tipping the balance of evidence in that direction.

Quantitative frequency security assessment method considering cumulative effect and its applications in frequency control

Rising wind and solar generation penetrations change power system frequency behaviors significantly. Large disturbances may cause serious frequency deviations and lead to stability problems. It is important to provide a comprehensive and quantitative frequency security assessment (FSA) method for situation awareness and control decision-making in power systems. In this paper, a new FSA approach considering cumulative effect of frequency deviations on power equipment is proposed to quantitatively assess the impact of power system frequency deviations. It provides a unified expression of frequency security index (FSI) and has advantages of linearity, smoothness and monotonicity over existing methods. The FSI is calculated based on frequency trajectory obtained from wide-area measurement system (WAMS) or numerical simulations by which wind and solar generation can be taken into account. With sensitivity analysis of frequency security margin, the proposed FSA method has been applied to critical disturbance and critical control amount searching with frequency security constraints. The searching procedure is easy to implement, and computationally efficient with good convergence. The feasibility of the proposed FSA method and its applications are demonstrated on the 10-machine 39-bus New England test system.

Tactile Situation Awareness System (TSAS) as a Compensatory Aid for Sensory Loss

The Tactile Situation Awareness System (TSAS) began as a sensory cue to counteract pilot spatial disorientation. More recent adaptations of TSAS provide feedback for postural instability and spatial cues for persons with hearing loss. This demonstration included a brief presentation on past TSAS developments and recent applications. Attendees experienced an interactive demonstration of the TSAS hover-drift countermeasure for helicopter pilots, as well as recent applications of vibrotactile cues for looming, for postural stability, and for aiding target localization in pilots with noise-induced hearing loss.

Recommendation System Based on Fuzzy Cognitive Map

With the increase of data volume and visitor volume, the website faces great challenge in the environment of network. How to know the users' requirements rapidly and effectively and recommend the required information to the user becomes the research direction of all websites. The researchers of recommendation system propose a series of recommendation system models and algorithms for the user. The common challenge faced by these algorithms is how to judge the user intention and recommend the relevant content by little user action. The paper proposes the user situation awareness and information recommendation system based on fuzzy clustering analysis and fuzzy cognitive maps, and verifies the validity of the algorithm by the application to recommendation site of academic thesis.

Multiple Event Detection and Recognition Through Sparse Unmixing for High-Resolution Situational Awareness in Power Grid

A situational awareness system is essential to provide accurate understanding of power system dynamics, such that proper actions can be taken in real time in response to system disturbances and to avoid cascading blackouts. Event analysis has been an important component in any situational awareness system. However, most state-of-the-art techniques can only handle single event analysis. This paper tackles the challenging problem of multiple event detection and recognition. We propose a new conceptual framework, referred to as event unmixing, where we consider real-world events mixtures of more than one constituent root event. This concept is a key enabler for analysis of events to go beyond what are immediately detectable in a system, providing high-resolution data understanding at a finer scale. We interpret the event formation process from a linear mixing perspective and propose an innovative nonnegative sparse event unmixing (NSEU) algorithm for multiple event separation and temporal localization. The proposed framework has been evaluated using both PSS/E simulated cases and real event cases collected from the frequency disturbance recorders (FDRs) of the Frequency Monitoring Network (FNET). The experimental results demonstrate that the framework is reliable to detect and recognize multiple cascading events as well as their time of occurrence with high accuracy.

Enhancing evacuation plans with a situation awareness system based on end-user knowledge provision.

Recent disasters have shown that having clearly defined preventive procedures and decisions is a critical component that minimizes evacuation hazards and ensures a rapid and successful evolution of evacuation plans. In this context, we present our Situation-Aware System for enhancing Evacuation Plans (SASEP) system, which allows creating end-user business rules that technically support the specific events, conditions and actions related to evacuation plans. An experimental validation was carried out where 32 people faced a simulated emergency situation, 16 of them using SASEP and the other 16 using a legacy system based on static signs. From the results obtained, we compare both techniques and discuss in which situations SASEP offers a better evacuation route option, confirming that it is highly valuable when there is a threat in the evacuation route. In addition, a study about user satisfaction using both systems is presented showing in which cases the systems are assessed as satisfactory, relevant and not frustrating.

A situation-aware system for the detection of motion disorders of patients with Autism Spectrum Disorders

Patients with Autism Spectrum Disorders (ASD) show symptoms that in general fall into three areas: (1) social impairment; (2) communication difficulties; and, (3) repetitive and stereotyped behaviors. This paper presents a method and an infrastructure for the detection of the stereotyped motion disorders of patients with ASD. The method adopts Artificial Intelligence techniques for the identification of stereotyped motion disorders and the Situation-Awareness paradigm for the reduction of misclassifications and the extraction of further information useful for clinicians. Signals caught by accelerometers are pre-processed to obtain features that, in turn, are passed to the classifier that classifies the current temporal frame in order to detect stereotyped motions. Once a stereotyped motion is detected, events are generated for intelligent situation-aware components, which collect information related to the frequency and period of the day of the disorders, and help also to reduce false positives and misclassifications by verifying spatio-temporal constraints. Quantitatively, the off-line classifier has shown an accuracy of over 99%; whereas the on-line classifier has an accuracy of 92%. The research activity has been conducted in cooperation with clinicians of the Department of Child Psychiatry at the Children’s Hospital Santobono-Pausilipon in Naples, a prototype is deployed and tested at the hospital.

Research on Individual Soldier Radio Surveillance Equipment for Battlefield Situation Awareness

Individual soldier plays a more and more important role in the complex environment of battlefield electromagnetism, and its combat ability should be improved rapidly. A situation awareness system based on individual soldier radio surveillance equipment is presented. The probable equipment adapts mini size and low power hardware and intelligent signal processing technology. In this system, every soldier acts as a reconnaissance sensor, and also he can be a node among the battlefield situation awareness network. The system can improve the ability of battlefield situation awareness and the combat ability in the future information battlefield.

Research of Immune Network Defense System Based on Black Hole Theory

Active defense technology may predict future attack situation and detect unknown attacks, but it has many questions to will be researched: vulnerability, lower mal-ware detection rate, security situation awareness technology has faced problem of inter-organization cooperation, real-time response, correlation analysis, high-load low fault tolerance. Artificial immune technology combines with active defense technology to solve integrated artificial immune security situation awareness system with artificial immune technology and active defense technology by Black Hole theory and for diversification ad development characteristics of the artificial immune and active defense, gives a method about simulating Black Hole accretion theory to achieve absorption and utilization a variety of security and virus technology; a no escaped mechanism simulate the Black Hole; a method about access control method based on Hawking radiation theory. Based on the above work, applies virtual and sandbox technology to achieve network system itself virus immunity, and then that we implement re-engineering and reverse engineering for virus technology in order to study virus and dig more holes, create unified integrated defense tactics, so this defense system will improve ability of situation comprehension, situation prediction and intelligence decision.

Modeling and Simulation of Space Situation Awareness System Based on Parallel Control Theory

The basic components and complex property of SSA (space situational awareness) system is introduced. It is elaborated that the reason and method of researching SSA system based on parallel control theory. Specific idea and steps of modeling and simulation are proposed through ACP method of parallel control theory, and a simple simulated instance was used as a prototype of achieving artificial system of SSA.

ICARFAD: A Novel Framework for Improved Network Security Situation Awareness

Networking components and technologies is continuously proving their presence in various core areas of business like IT, Health Care, Stocks, and Emergencies with Military systems. It is possible by applying multiple system phenomenons of compatibility, interoperability and integration of different categories of devices and users. As the usage of information is increasing the transaction and data security needs to be provided effectively. It will serve as a critical and important task which assures data protection. This unexpected and frequent changes in the system is measured which gives a direction of vulnerable behaviour and the criticality of affecting the process. Accessing this information through actual network conditions and changes for improving the security is comes under the area of situational awareness system. This work proposes a novel ICARFAD (Information Collection, Assessment and Response, Feedback and Alerts Decisions) based situation awareness mechanism which gathers current network condition and clearly defines the boundaries by which security solutions can be designed effectively. It reflects all the changes made in configurations and methods taken as a security measures by maintaining a database which later on used to make the decisions for network security improvements. It also makes the visualization of attack conditions by making the graphs and plots which greatly improves the rate and the quality measures of persons or machines decision making.

Tactile Cues in Continuous Operations: A Preliminary Study

Research has shown that tactile displays are an effective tool for augmenting spatial orientation and situation awareness information provided to aircraft operators. The tactile situation awareness system (TSAS) has been shown to improve flight performance in conditions of degraded visual environments and to safely maintain performance during hover over moving targets. The potential for the user to adapt and habituate to the stimulus of tactile display systems has not yet been investigated. Four UH-60 current, rated aviators (all male) participated in the pilot study. Subjects completed four consecutive iterations of a 3-h flight profile consisting of 10 maneuvers, totaling 12 h of continuous flight. Flight performance, tactor information, responses to a discomfort questionnaire, and ratings of fatigue symptoms were recorded. The independent variable in all analyses was session (four levels). The results showed that performance per maneuver and proportion of stimulus cues (measure of response to cues) per maneuver were consistent across sessions using independent-samples Kruskal-Wallis tests. The findings of this preliminary assessment support the use of tactile displays (consistent with parameters of TSAS) in continuous operations since performance and proportion of stimulus cues presented was consistent over a period of 12 h. In conclusion, the system will require further experimental testing, but these preliminary findings do not suggest performance or response to be affected by any adaptation or habituation to the stimulus.

Crowd Modelling for Quasi-real-time Feedback during Evacuation in a Situational Awareness System

Evacuation modelling has traditionally been limited to prior analysis of the geometrical design of spaces. This approach is limited by the number of scenarios that can be tested. A scenario-independent evacuation model would rely on real-time information processing. This approach allows the generation of an optimum evacuation strategy that minimises evacuation time and crowd density, and is tailored to the current situation at hand. This paper describes the requirements and development of such a crowd model. Graph theory and network flow heuristics are combined with agent movement, based on the individual determination of speed by meso-scale density assessment.

Situational Awareness and Emergent Response Systems in the Context of Stages of Clinical Deterioration in the Hospital

Situational Awareness and Emergent Response Systems in the Context of Stages of Clinical Deterioration in the Hospital

Integration of Social Resources: Joint Command System in Large-Scale Emergencies

Command system is the core part in responding large-scale emergencies. Central government needs to integrate social resources in constructing command system rapidly. Social resources from military, enterprises, government and non-government organization should be integrated in command system which includes situational awareness system, communication system and decision system. The architectures of these systems are described in turn. Military command system should be the main part and backbone in large-scale emergencies.