Coping with Disaster: The Case of Israeli Adolescents under Threat of Missile Attack.

ERIC Educational Resources Information Center

Zeidner, Moshe

1993-01-01

Studied the relationships of coping resources, optimism, perceived control, and coping strategies to anxiety, physical symptoms, and cognitive functioning for 69 male and 40 female Jewish Israeli adolescents in real crisis during the Persian Gulf War. Discusses the implications of the reported mixture of active and palliative coping strategies.…

Nonlinear dynamics of team performance and adaptability in emergency response.

PubMed

Guastello, Stephen J

2010-04-01

The impact of team size and performance feedback on adaptation levels and performance of emergency response (ER) teams was examined to introduce a metric for quantifying adaptation levels based on nonlinear dynamical systems (NDS) theory. NDS principles appear in reports surrounding Hurricane Katrina, earthquakes, floods, a disease epidemic, and the Southeast Asian tsunami. They are also intrinsic to coordination within teams, adaptation levels, and performance in dynamic decision processes. Performance was measured in a dynamic decision task in which ER teams of different sizes worked against an attacker who was trying to destroy a city (total N = 225 undergraduates). The complexity of teams' and attackers' adaptation strategies and the role of the opponents' performance were assessed by nonlinear regression analysis. An optimal group size for team performance was identified. Teams were more readily influenced by the attackers' performance than vice versa. The adaptive capabilities of attackers and teams were impaired by their opponents in some conditions. ER teams should be large enough to contribute a critical mass of ideas but not so large that coordination would be compromised. ER teams used self-organized strategies that could have been more adaptive, whereas attackers used chaotic strategies. The model and results are applicable to ER processes or training maneuvers involving dynamic decisions but could be limited to nonhierarchical groups.

An analytic approach to cyber adversarial dynamics

NASA Astrophysics Data System (ADS)

Sweeney, Patrick; Cybenko, George

2012-06-01

To date, cyber security investment by both the government and commercial sectors has been largely driven by the myopic best response of players to the actions of their adversaries and their perception of the adversarial environment. However, current work in applying traditional game theory to cyber operations typically assumes that games exist with prescribed moves, strategies, and payos. This paper presents an analytic approach to characterizing the more realistic cyber adversarial metagame that we believe is being played. Examples show that understanding the dynamic metagame provides opportunities to exploit an adversary's anticipated attack strategy. A dynamic version of a graph-based attack-defend game is introduced, and a simulation shows how an optimal strategy can be selected for success in the dynamic environment.

Robustness of coevolution in resolving prisoner's dilemma games on interdependent networks subject to attack

NASA Astrophysics Data System (ADS)

Liu, Penghui; Liu, Jing

2017-08-01

Recently, coevolution between strategy and network structure has been established as a rule to resolve social dilemmas and reach optimal situations for cooperation. Many follow-up researches have focused on studying how coevolution helps networks reorganize to deter the defectors and many coevolution methods have been proposed. However, the robustness of the coevolution rules against attacks have not been studied much. Since attacks may directly influence the original evolutionary process of cooperation, the robustness should be an important index while evaluating the quality of a coevolution method. In this paper, we focus on investigating the robustness of an elementary coevolution method in resolving the prisoner's dilemma game upon the interdependent networks. Three different types of time-independent attacks, named as edge attacks, instigation attacks and node attacks have been employed to test its robustness. Through analyzing the simulation results obtained, we find this coevolution method is relatively robust against the edge attack and the node attack as it successfully maintains cooperation in the population over the entire attack range. However, when the instigation probability of the attacked individuals is large or the attack range of instigation attack is wide enough, coevolutionary rule finally fails in maintaining cooperation in the population.

Numerical simulation of the optimal two-mode attacks for two-way continuous-variable quantum cryptography in reverse reconciliation

NASA Astrophysics Data System (ADS)

Zhang, Yichen; Li, Zhengyu; Zhao, Yijia; Yu, Song; Guo, Hong

2017-02-01

We analyze the security of the two-way continuous-variable quantum key distribution protocol in reverse reconciliation against general two-mode attacks, which represent all accessible attacks at fixed channel parameters. Rather than against one specific attack model, the expression of secret key rates of the two-way protocol are derived against all accessible attack models. It is found that there is an optimal two-mode attack to minimize the performance of the protocol in terms of both secret key rates and maximal transmission distances. We identify the optimal two-mode attack, give the specific attack model of the optimal two-mode attack and show the performance of the two-way protocol against the optimal two-mode attack. Even under the optimal two-mode attack, the performances of two-way protocol are still better than the corresponding one-way protocol, which shows the advantage of making double use of the quantum channel and the potential of long-distance secure communication using a two-way protocol.

Optimization of robustness of interdependent network controllability by redundant design

PubMed Central

2018-01-01

Controllability of complex networks has been a hot topic in recent years. Real networks regarded as interdependent networks are always coupled together by multiple networks. The cascading process of interdependent networks including interdependent failure and overload failure will destroy the robustness of controllability for the whole network. Therefore, the optimization of the robustness of interdependent network controllability is of great importance in the research area of complex networks. In this paper, based on the model of interdependent networks constructed first, we determine the cascading process under different proportions of node attacks. Then, the structural controllability of interdependent networks is measured by the minimum driver nodes. Furthermore, we propose a parameter which can be obtained by the structure and minimum driver set of interdependent networks under different proportions of node attacks and analyze the robustness for interdependent network controllability. Finally, we optimize the robustness of interdependent network controllability by redundant design including node backup and redundancy edge backup and improve the redundant design by proposing different strategies according to their cost. Comparative strategies of redundant design are conducted to find the best strategy. Results shows that node backup and redundancy edge backup can indeed decrease those nodes suffering from failure and improve the robustness of controllability. Considering the cost of redundant design, we should choose BBS (betweenness-based strategy) or DBS (degree based strategy) for node backup and HDF(high degree first) for redundancy edge backup. Above all, our proposed strategies are feasible and effective at improving the robustness of interdependent network controllability. PMID:29438426

Timing of prophylactic surgery in prevention of diverticulitis recurrence: a cost-effectiveness analysis.

PubMed

Richards, Robert J; Hammitt, James K

2002-09-01

Although surgery is recommended after two or more attacks of uncomplicated diverticulitis, the optimal timing for surgery in terms of cost-effectiveness is unknown. A Markov model was used to compare the costs and outcomes of performing surgery after one, two, or three uncomplicated attacks in 60-year-old hypothetical cohorts. Transition state probabilities were assigned values using published data and expert opinion. Costs were estimated from Medicare reimbursement rates. Surgery after the third attack is cost saving, yielding more years of life and quality adjusted life years at a lower cost than the other two strategies. The results were not sensitive to many of the variables tested in the model or to changes made in the discount rate (0-5%). In conclusion, performing prophylactic resection after the third attack of diverticulitis is cost saving in comparison to resection performed after the first or second attacks and remains cost-effective during sensitivity analysis.

Cyber attack analysis on cyber-physical systems: Detectability, severity, and attenuation strategy

NASA Astrophysics Data System (ADS)

Kwon, Cheolhyeon

Security of Cyber-Physical Systems (CPS) against malicious cyber attacks is an important yet challenging problem. Since most cyber attacks happen in erratic ways, it is usually intractable to describe and diagnose them systematically. Motivated by such difficulties, this thesis presents a set of theories and algorithms for a cyber-secure architecture of the CPS within the control theoretic perspective. Here, instead of identifying a specific cyber attack model, we are focused on analyzing the system's response during cyber attacks. Firstly, we investigate the detectability of the cyber attacks from the system's behavior under cyber attacks. Specifically, we conduct a study on the vulnerabilities in the CPS's monitoring system against the stealthy cyber attack that is carefully designed to avoid being detected by its detection scheme. After classifying three kinds of cyber attacks according to the attacker's ability to compromise the system, we derive the necessary and sufficient conditions under which such stealthy cyber attacks can be designed to cause the unbounded estimation error while not being detected. Then, the analytical design method of the optimal stealthy cyber attack that maximizes the estimation error is developed. The proposed stealthy cyber attack analysis is demonstrated with illustrative examples on Air Traffic Control (ATC) system and Unmanned Aerial Vehicle (UAV) navigation system applications. Secondly, in an attempt to study the CPSs' vulnerabilities in more detail, we further discuss a methodology to identify potential cyber threats inherent in the given CPSs and quantify the attack severity accordingly. We then develop an analytical algorithm to test the behavior of the CPS under various cyber attack combinations. Compared to a numerical approach, the analytical algorithm enables the prediction of the most effective cyber attack combinations without computing the severity of all possible attack combinations, thereby greatly reducing the computational cost. The proposed algorithm is validated through a linearized longitudinal motion of a UAV example. Finally, we propose an attack attenuation strategy via the controller design for CPSs that are robust to various types of cyber attacks. While the previous studies have investigated a secure control by assuming a specific attack strategy, in this research we propose a hybrid robust control scheme that contains multiple sub-controllers, each matched to a specific type of cyber attacks. Then the system can be adapted to various cyber attacks (including those that are not assumed for sub-controller design) by switching its sub-controllers to achieve the best performance. Then, a method for designing a secure switching logic to counter all possible cyber attacks is proposed and it verifies mathematically the system's performance and stability as well. The performance of the proposed control scheme is demonstrated by an example with the hybrid H2 - H-infinity controller applied to a UAV example.

Aerodynamic shape optimization using preconditioned conjugate gradient methods

NASA Technical Reports Server (NTRS)

Burgreen, Greg W.; Baysal, Oktay

1993-01-01

In an effort to further improve upon the latest advancements made in aerodynamic shape optimization procedures, a systematic study is performed to examine several current solution methodologies as applied to various aspects of the optimization procedure. It is demonstrated that preconditioned conjugate gradient-like methodologies dramatically decrease the computational efforts required for such procedures. The design problem investigated is the shape optimization of the upper and lower surfaces of an initially symmetric (NACA-012) airfoil in inviscid transonic flow and at zero degree angle-of-attack. The complete surface shape is represented using a Bezier-Bernstein polynomial. The present optimization method then automatically obtains supercritical airfoil shapes over a variety of freestream Mach numbers. Furthermore, the best optimization strategy examined resulted in a factor of 8 decrease in computational time as well as a factor of 4 decrease in memory over the most efficient strategies in current use.

Security under Uncertainty: Adaptive Attackers Are More Challenging to Human Defenders than Random Attackers

PubMed Central

Moisan, Frédéric; Gonzalez, Cleotilde

2017-01-01

Game Theory is a common approach used to understand attacker and defender motives, strategies, and allocation of limited security resources. For example, many defense algorithms are based on game-theoretic solutions that conclude that randomization of defense actions assures unpredictability, creating difficulties for a human attacker. However, many game-theoretic solutions often rely on idealized assumptions of decision making that underplay the role of human cognition and information uncertainty. The consequence is that we know little about how effective these algorithms are against human players. Using a simplified security game, we study the type of attack strategy and the uncertainty about an attacker's strategy in a laboratory experiment where participants play the role of defenders against a simulated attacker. Our goal is to compare a human defender's behavior in three levels of uncertainty (Information Level: Certain, Risky, Uncertain) and three types of attacker's strategy (Attacker's strategy: Minimax, Random, Adaptive) in a between-subjects experimental design. Best defense performance is achieved when defenders play against a minimax and a random attack strategy compared to an adaptive strategy. Furthermore, when payoffs are certain, defenders are as efficient against random attack strategy as they are against an adaptive strategy, but when payoffs are uncertain, defenders have most difficulties defending against an adaptive attacker compared to a random attacker. We conclude that given conditions of uncertainty in many security problems, defense algorithms would be more efficient if they are adaptive to the attacker actions, taking advantage of the attacker's human inefficiencies. PMID:28690557

Escape strategies for turboprop aircraft in microburst windshear

NASA Technical Reports Server (NTRS)

Bobbitt, Richard B.; Howard, Richard M.

1991-01-01

The dynamic reponse of a P-3 aircraft and a light twin-engine turboprop to a low-level microburst encounter is modeled. The response to the microburst is depicted for various escape maneuvers. Plots of altitude, velocity, and specific energy are shown for all cases. Takeoff escape strategies are discussed. The optimal escape procedure is found to be flying a constant value of pitch angle. Constant angle of attack maneuvers sometimes result in superior performance.

Finite Energy and Bounded Actuator Attacks on Cyber-Physical Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Djouadi, Seddik M; Melin, Alexander M; Ferragut, Erik M

As control system networks are being connected to enterprise level networks for remote monitoring, operation, and system-wide performance optimization, these same connections are providing vulnerabilities that can be exploited by malicious actors for attack, financial gain, and theft of intellectual property. Much effort in cyber-physical system (CPS) protection has focused on protecting the borders of the system through traditional information security techniques. Less effort has been applied to the protection of cyber-physical systems from intelligent attacks launched after an attacker has defeated the information security protections to gain access to the control system. In this paper, attacks on actuator signalsmore » are analyzed from a system theoretic context. The threat surface is classified into finite energy and bounded attacks. These two broad classes encompass a large range of potential attacks. The effect of theses attacks on a linear quadratic (LQ) control are analyzed, and the optimal actuator attacks for both finite and infinite horizon LQ control are derived, therefore the worst case attack signals are obtained. The closed-loop system under the optimal attack signals is given and a numerical example illustrating the effect of an optimal bounded attack is provided.« less

Cooperating attackers in neural cryptography.

PubMed

Shacham, Lanir N; Klein, Einat; Mislovaty, Rachel; Kanter, Ido; Kinzel, Wolfgang

2004-06-01

A successful attack strategy in neural cryptography is presented. The neural cryptosystem, based on synchronization of neural networks by mutual learning, has been recently shown to be secure under different attack strategies. The success of the advanced attacker presented here, called the "majority-flipping attacker," does not decay with the parameters of the model. This attacker's outstanding success is due to its using a group of attackers which cooperate throughout the synchronization process, unlike any other attack strategy known. An analytical description of this attack is also presented, and fits the results of simulations.

Analysis of metro network performance from a complex network perspective

NASA Astrophysics Data System (ADS)

Wu, Xingtang; Dong, Hairong; Tse, Chi Kong; Ho, Ivan W. H.; Lau, Francis C. M.

2018-02-01

In this paper, the performance of metro networks is studied from a network science perspective. We review the structural efficiency of metro networks on the basis of a passenger's intuitive routing strategy that optimizes the number of transfers and the distance traveled.A new node centrality measure, called node occupying probability, is introduced for evaluating the level of utilization of stations. The robustness of a metro network is analyzed under several attack scenarios. Six metro networks (Beijing, London, Paris, Hong Kong, Tokyo and New York) are compared in terms of the node occupying probability and a few other performance parameters. Simulation results show that the New York metro system has better topological efficiency, the Tokyo and Hong Kong systems are the most robust under random attack and target attack, respectively.

Photon-number-splitting versus cloning attacks in practical implementations of the Bennett-Brassard 1984 protocol for quantum cryptography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Niederberger, Armand; Scarani, Valerio; Gisin, Nicolas

2005-04-01

In practical quantum cryptography, the source sometimes produces multiphoton pulses, thus enabling the eavesdropper Eve to perform the powerful photon-number-splitting (PNS) attack. Recently, it was shown by Curty and Luetkenhaus [Phys. Rev. A 69, 042321 (2004)] that the PNS attack is not always the optimal attack when two photons are present: if errors are present in the correlations Alice-Bob and if Eve cannot modify Bob's detection efficiency, Eve gains a larger amount of information using another attack based on a 2{yields}3 cloning machine. In this work, we extend this analysis to all distances Alice-Bob. We identify a new incoherent 2{yields}3more » cloning attack which performs better than those described before. Using it, we confirm that, in the presence of errors, Eve's better strategy uses 2{yields}3 cloning attacks instead of the PNS. However, this improvement is very small for the implementations of the Bennett-Brassard 1984 (BB84) protocol. Thus, the existence of these new attacks is conceptually interesting but basically does not change the value of the security parameters of BB84. The main results are valid both for Poissonian and sub-Poissonian sources.« less

Dangerous nutrients: evolution of phytoplankton resource uptake subject to virus attack.

PubMed

Menge, Duncan N L; Weitz, Joshua S

2009-03-07

Phytoplankton need multiple resources to grow and reproduce (such as nitrogen, phosphorus, and iron), but the receptors through which they acquire resources are, in many cases, the same channels through which viruses attack. Therefore, phytoplankton can face a bottom-up vs. top-down tradeoff in receptor allocation: Optimize resource uptake or minimize virus attack? We investigate this top-down vs. bottom-up tradeoff using an evolutionary ecology model of multiple essential resources, specialist viruses that attack through the resource receptors, and a phytoplankton population that can evolve to alter the fraction of receptors used for each resource/virus type. Without viruses present the singular continuously stable strategy is to allocate receptors such that resources are co-limiting, which also minimizes the equilibrium concentrations of both resources. Only one virus type can be present at equilibrium (because phytoplankton, in this model, are a single resource for viruses), and when a virus type is present, it controls the equilibrium phytoplankton population size. Despite this top-down control on equilibrium densities, bottom-up control determines the evolutionary outcome. Regardless of which virus type is present, the allocation strategy that yields co-limitation between the two resources is continuously stable. This is true even when the virus type attacking through the limiting resource channel is present, even though selection for co-limitation in this case decreases the equilibrium phytoplankton population and does not decrease the equilibrium concentration of the limiting resource. Therefore, although moving toward co-limitation and decreasing the equilibrium concentration of the limiting resource often co-occur in models, it is co-limitation, and not necessarily the lowest equilibrium concentration of the limiting resource, that is the result of selection. This result adds to the growing body of literature suggesting that co-limitation at equilibrium is a winning strategy.

Understanding the dynamics of terrorism events with multiple-discipline datasets and machine learning approach

PubMed Central

Ding, Fangyu; Ge, Quansheng; Fu, Jingying; Hao, Mengmeng

2017-01-01

Terror events can cause profound consequences for the whole society. Finding out the regularity of terrorist attacks has important meaning for the global counter-terrorism strategy. In the present study, we demonstrate a novel method using relatively popular and robust machine learning methods to simulate the risk of terrorist attacks at a global scale based on multiple resources, long time series and globally distributed datasets. Historical data from 1970 to 2015 was adopted to train and evaluate machine learning models. The model performed fairly well in predicting the places where terror events might occur in 2015, with a success rate of 96.6%. Moreover, it is noteworthy that the model with optimized tuning parameter values successfully predicted 2,037 terrorism event locations where a terrorist attack had never happened before. PMID:28591138

Understanding the dynamics of terrorism events with multiple-discipline datasets and machine learning approach.

PubMed

Ding, Fangyu; Ge, Quansheng; Jiang, Dong; Fu, Jingying; Hao, Mengmeng

2017-01-01

Terror events can cause profound consequences for the whole society. Finding out the regularity of terrorist attacks has important meaning for the global counter-terrorism strategy. In the present study, we demonstrate a novel method using relatively popular and robust machine learning methods to simulate the risk of terrorist attacks at a global scale based on multiple resources, long time series and globally distributed datasets. Historical data from 1970 to 2015 was adopted to train and evaluate machine learning models. The model performed fairly well in predicting the places where terror events might occur in 2015, with a success rate of 96.6%. Moreover, it is noteworthy that the model with optimized tuning parameter values successfully predicted 2,037 terrorism event locations where a terrorist attack had never happened before.

HackAttack: Game-Theoretic Analysis of Realistic Cyber Conflicts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferragut, Erik M; Brady, Andrew C; Brady, Ethan J

Game theory is appropriate for studying cyber conflict because it allows for an intelligent and goal-driven adversary. Applications of game theory have led to a number of results regarding optimal attack and defense strategies. However, the overwhelming majority of applications explore overly simplistic games, often ones in which each participant s actions are visible to every other participant. These simplifications strip away the fundamental properties of real cyber conflicts: probabilistic alerting, hidden actions, unknown opponent capabilities. In this paper, we demonstrate that it is possible to analyze a more realistic game, one in which different resources have different weaknesses, playersmore » have different exploits, and moves occur in secrecy, but they can be detected. Certainly, more advanced and complex games are possible, but the game presented here is more realistic than any other game we know of in the scientific literature. While optimal strategies can be found for simpler games using calculus, case-by-case analysis, or, for stochastic games, Q-learning, our more complex game is more naturally analyzed using the same methods used to study other complex games, such as checkers and chess. We define a simple evaluation function and employ multi-step searches to create strategies. We show that such scenarios can be analyzed, and find that in cases of extreme uncertainty, it is often better to ignore one s opponent s possible moves. Furthermore, we show that a simple evaluation function in a complex game can lead to interesting and nuanced strategies.« less

Optimal response to attacks on the open science grids.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Altunay, M.; Leyffer, S.; Linderoth, J. T.

2011-01-01

Cybersecurity is a growing concern, especially in open grids, where attack propagation is easy because of prevalent collaborations among thousands of users and hundreds of institutions. The collaboration rules that typically govern large science experiments as well as social networks of scientists span across the institutional security boundaries. A common concern is that the increased openness may allow malicious attackers to spread more readily around the grid. We consider how to optimally respond to attacks in open grid environments. To show how and why attacks spread more readily around the grid, we first discuss how collaborations manifest themselves in themore » grids and form the collaboration network graph, and how this collaboration network graph affects the security threat levels of grid participants. We present two mixed-integer program (MIP) models to find the optimal response to attacks in open grid environments, and also calculate the threat level associated with each grid participant. Given an attack scenario, our optimal response model aims to minimize the threat levels at unaffected participants while maximizing the uninterrupted scientific production (continuing collaborations). By adopting some of the collaboration rules (e.g., suspending a collaboration or shutting down a site), the model finds optimal response to subvert an attack scenario.« less

Simple proof that Gaussian attacks are optimal among collective attacks against continuous-variable quantum key distribution with a Gaussian modulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leverrier, Anthony; Grangier, Philippe; Laboratoire Charles Fabry, Institut d'Optique, CNRS, University Paris-Sud, Campus Polytechnique, RD 128, F-91127 Palaiseau Cedex

2010-06-15

In this article, we give a simple proof of the fact that the optimal collective attacks against continuous-variable quantum key distribution with a Gaussian modulation are Gaussian attacks. Our proof, which makes use of symmetry properties of the protocol in phase space, is particularly relevant for the finite-key analysis of the protocol and therefore for practical applications.

Inertia may limit efficiency of slow flapping flight, but mayflies show a strategy for reducing the power requirements of loiter.

PubMed

Usherwood, James R

2009-03-01

Predictions from aerodynamic theory often match biological observations very poorly. Many insects and several bird species habitually hover, frequently flying at low advance ratios. Taking helicopter-based aerodynamic theory, wings functioning predominantly for hovering, even for quite small insects, should operate at low angles of attack. However, insect wings operate at very high angles of attack during hovering; reduction in angle of attack should result in considerable energetic savings. Here, I consider the possibility that selection of kinematics is constrained from being aerodynamically optimal due to the inertial power requirements of flapping. Potential increases in aerodynamic efficiency with lower angles of attack during hovering may be outweighed by increases in inertial power due to the associated increases in flapping frequency. For simple hovering, traditional rotary-winged helicopter-like micro air vehicles would be more efficient than their flapping biomimetic counterparts. However, flapping may confer advantages in terms of top speed and manoeuvrability. If flapping-winged micro air vehicles are required to hover or loiter more efficiently, dragonflies and mayflies suggest biomimetic solutions.

Cyber situational awareness and differential hardening

NASA Astrophysics Data System (ADS)

Dwivedi, Anurag; Tebben, Dan

2012-06-01

The advent of cyber threats has created a need for a new network planning, design, architecture, operations, control, situational awareness, management, and maintenance paradigms. Primary considerations include the ability to assess cyber attack resiliency of the network, and rapidly detect, isolate, and operate during deliberate simultaneous attacks against the network nodes and links. Legacy network planning relied on automatic protection of a network in the event of a single fault or a very few simultaneous faults in mesh networks, but in the future it must be augmented to include improved network resiliency and vulnerability awareness to cyber attacks. Ability to design a resilient network requires the development of methods to define, and quantify the network resiliency to attacks, and to be able to develop new optimization strategies for maintaining operations in the midst of these newly emerging cyber threats. Ways to quantify resiliency, and its use in visualizing cyber vulnerability awareness and in identifying node or link criticality, are presented in the current work, as well as a methodology of differential network hardening based on the criticality profile of cyber network components.

Attacker-defender game from a network science perspective

NASA Astrophysics Data System (ADS)

Li, Ya-Peng; Tan, Suo-Yi; Deng, Ye; Wu, Jun

2018-05-01

Dealing with the protection of critical infrastructures, many game-theoretic methods have been developed to study the strategic interactions between defenders and attackers. However, most game models ignore the interrelationship between different components within a certain system. In this paper, we propose a simultaneous-move attacker-defender game model, which is a two-player zero-sum static game with complete information. The strategies and payoffs of this game are defined on the basis of the topology structure of the infrastructure system, which is represented by a complex network. Due to the complexity of strategies, the attack and defense strategies are confined by two typical strategies, namely, targeted strategy and random strategy. The simulation results indicate that in a scale-free network, the attacker virtually always attacks randomly in the Nash equilibrium. With a small cost-sensitive parameter, representing the degree to which costs increase with the importance of a target, the defender protects the hub targets with large degrees preferentially. When the cost-sensitive parameter exceeds a threshold, the defender switches to protecting nodes randomly. Our work provides a new theoretical framework to analyze the confrontations between the attacker and the defender on critical infrastructures and deserves further study.

Prediction of pilot-aircraft stability boundaries and performance contours

NASA Technical Reports Server (NTRS)

Stengel, R. F.; Broussard, J. R.

1977-01-01

Control-theoretic pilot models can provide important new insights regarding the stability and performance characteristics of the pilot-aircraft system. Optimal-control pilot models can be formed for a wide range of flight conditions, suggesting that the human pilot can maintain stability if he adapts his control strategy to the aircraft's changing dynamics. Of particular concern is the effect of sub-optimal pilot adaptation as an aircraft transitions from low to high angle-of-attack during rapid maneuvering, as the changes in aircraft stability and control response can be extreme. This paper examines the effects of optimal and sub-optimal effort during a typical 'high-g' maneuver, and it introduces the concept of minimum-control effort (MCE) adaptation. Limited experimental results tend to support the MCE adaptation concept.

Optimal Resource Allocation in Electrical Network Defense

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yao, Y; Edmunds, T; Papageorgiou, D

2004-01-15

Infrastructure networks supplying electricity, natural gas, water, and other commodities are at risk of disruption due to well-engineered and coordinated terrorist attacks. Countermeasures such as hardening targets, acquisition of spare critical components, and surveillance can be undertaken to detect and deter these attacks. Allocation of available countermeasures resources to sites or activities in a manner that maximizes their effectiveness is a challenging problem. This allocation must take into account the adversary's response after the countermeasure assets are in place and consequence mitigation measures the infrastructure operation can undertake after the attack. The adversary may simply switch strategies to avoid countermeasuresmore » when executing the attack. Stockpiling spares of critical energy infrastructure components has been identified as a key element of a grid infrastructure defense strategy in a recent National Academy of Sciences report [1]. Consider a scenario where an attacker attempts to interrupt the service of an electrical network by disabling some of its facilities while a defender wants to prevent or minimize the effectiveness of any attack. The interaction between the attacker and the defender can be described in three stages: (1) The defender deploys countermeasures, (2) The attacker disrupts the network, and (3) The defender responds to the attack by rerouting power to maintain service while trying to repair damage. In the first stage, the defender considers all possible attack scenarios and deploys countermeasures to defend against the worst scenarios. Countermeasures can include hardening targets, acquiring spare critical components, and installing surveillance devices. In the second stage, the attacker, with full knowledge of the deployed countermeasures, attempts to disable some nodes or links in the network to inflict the greatest loss on the defender. In the third stage, the defender re-dispatches power and restores disabled nodes or links to minimize the loss. The loss can be measured in costs, including the costs of using more expensive generators and the economic losses that can be attributed to loss of load. The defender's goal is to minimize the loss while the attacker wants to maximize it. Assuming some level of budget constraint, each side can only defend or attack a limited number of network elements. When an element is attacked, it is assumed that it will be totally disabled. It is assumed that when an element is defended it cannot be disabled, which may mean that it will be restored in a very short time after being attacked. The rest of the paper is organized as follows. Section 2 will briefly review literature related to multilevel programming and network defense. Section 3 presents a mathematical formulation of the electrical network defense problem. Section 4 describes the solution algorithms. Section 5 discusses computational results. Finally, Sec. 6 explores future research directions.« less

Attacks and Countermeasures in Communications and Power Networks

DTIC Science & Technology

2014-01-01

the victim. This strategy is often used to confuse the intrusion detection system about the adversary’s location. If the adversary compromises a pair...1.2 Detection of Information Flows Detection of information flows between a pair of nodes has been studied in the context of network intrusion ...Theo- rem 3.3.4 were derived purely based on the condition for undetectability. Hence, the same optimality statements hold for the noisy measurement

Stability and Topology of Scale-Free Networks under Attack and Defense Strategies

NASA Astrophysics Data System (ADS)

Gallos, Lazaros K.; Cohen, Reuven; Argyrakis, Panos; Bunde, Armin; Havlin, Shlomo

2005-05-01

We study tolerance and topology of random scale-free networks under attack and defense strategies that depend on the degree k of the nodes. This situation occurs, for example, when the robustness of a node depends on its degree or in an intentional attack with insufficient knowledge of the network. We determine, for all strategies, the critical fraction pc of nodes that must be removed for disintegrating the network. We find that, for an intentional attack, little knowledge of the well-connected sites is sufficient to strongly reduce pc. At criticality, the topology of the network depends on the removal strategy, implying that different strategies may lead to different kinds of percolation transitions.

Evaluating Moving Target Defense with PLADD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, Stephen T.; Outkin, Alexander V.; Gearhart, Jared Lee

This project evaluates the effectiveness of moving target defense (MTD) techniques using a new game we have designed, called PLADD, inspired by the game FlipIt [28]. PLADD extends FlipIt by incorporating what we believe are key MTD concepts. We have analyzed PLADD and proven the existence of a defender strategy that pushes a rational attacker out of the game, demonstrated how limited the strategies available to an attacker are in PLADD, and derived analytic expressions for the expected utility of the game’s players in multiple game variants. We have created an algorithm for finding a defender’s optimal PLADD strategy. Wemore » show that in the special case of achieving deterrence in PLADD, MTD is not always cost effective and that its optimal deployment may shift abruptly from not using MTD at all to using it as aggressively as possible. We believe our effort provides basic, fundamental insights into the use of MTD, but conclude that a truly practical analysis requires model selection and calibration based on real scenarios and empirical data. We propose several avenues for further inquiry, including (1) agents with adaptive capabilities more reflective of real world adversaries, (2) the presence of multiple, heterogeneous adversaries, (3) computational game theory-based approaches such as coevolution to allow scaling to the real world beyond the limitations of analytical analysis and classical game theory, (4) mapping the game to real-world scenarios, (5) taking player risk into account when designing a strategy (in addition to expected payoff), (6) improving our understanding of the dynamic nature of MTD-inspired games by using a martingale representation, defensive forecasting, and techniques from signal processing, and (7) using adversarial games to develop inherently resilient cyber systems.« less

The Follow-up Crisis: Optimizing Science in an Opportunity Rich Environment

NASA Astrophysics Data System (ADS)

Vestrand, T.

Rapid follow-up tasking for robotic telescopes has been dominated by a one-dimensional uncoordinated response strategy developed for gamma-ray burst studies. However, this second-grade soccer approach is increasing showing its limitations even when there are only a few events per night. And it will certainly fail when faced with the denial-of-service attack generated by the nightly flood of new transients generated by massive variability surveys like LSST. We discuss approaches for optimizing the scientific return from autonomous robotic telescopes in the high event range limit and explore the potential of a coordinated telescope ecosystem employing heterogeneous telescopes.

"Dateline NBC"'s Persuasive Attack on Wal-Mart.

ERIC Educational Resources Information Center

Benoit, William L.; Dorries, Bruce

1996-01-01

Develops a typology of persuasive attack strategies. Identifies two key components of persuasive attack: responsibility and offensiveness. Describes several strategies for intensifying each of these elements. Applies this analysis to "Dateline NBC"'s allegations that Wal-Mart's "Buy American" campaign was deceptive. Concludes…

Improving rotorcraft survivability to RPG attack using inverse methods

NASA Astrophysics Data System (ADS)

Anderson, D.; Thomson, D. G.

2009-09-01

This paper presents the results of a preliminary investigation of optimal threat evasion strategies for improving the survivability of rotorcraft under attack by rocket propelled grenades (RPGs). The basis of this approach is the application of inverse simulation techniques pioneered for simulation of aggressive helicopter manoeuvres to the RPG engagement problem. In this research, improvements in survivability are achieved by computing effective evasive manoeuvres. The first step in this process uses the missile approach warning system camera (MAWS) on the aircraft to provide angular information of the threat. Estimates of the RPG trajectory and impact point are then estimated. For the current flight state an appropriate evasion response is selected then realised via inverse simulation of the platform dynamics. Results are presented for several representative engagements showing the efficacy of the approach.

ReacKnock: Identifying Reaction Deletion Strategies for Microbial Strain Optimization Based on Genome-Scale Metabolic Network

PubMed Central

Xu, Zixiang; Zheng, Ping; Sun, Jibin; Ma, Yanhe

2013-01-01

Gene knockout has been used as a common strategy to improve microbial strains for producing chemicals. Several algorithms are available to predict the target reactions to be deleted. Most of them apply mixed integer bi-level linear programming (MIBLP) based on metabolic networks, and use duality theory to transform bi-level optimization problem of large-scale MIBLP to single-level programming. However, the validity of the transformation was not proved. Solution of MIBLP depends on the structure of inner problem. If the inner problem is continuous, Karush-Kuhn-Tucker (KKT) method can be used to reformulate the MIBLP to a single-level one. We adopt KKT technique in our algorithm ReacKnock to attack the intractable problem of the solution of MIBLP, demonstrated with the genome-scale metabolic network model of E. coli for producing various chemicals such as succinate, ethanol, threonine and etc. Compared to the previous methods, our algorithm is fast, stable and reliable to find the optimal solutions for all the chemical products tested, and able to provide all the alternative deletion strategies which lead to the same industrial objective. PMID:24348984

A novel metaheuristic for continuous optimization problems: Virus optimization algorithm

NASA Astrophysics Data System (ADS)

Liang, Yun-Chia; Rodolfo Cuevas Juarez, Josue

2016-01-01

A novel metaheuristic for continuous optimization problems, named the virus optimization algorithm (VOA), is introduced and investigated. VOA is an iteratively population-based method that imitates the behaviour of viruses attacking a living cell. The number of viruses grows at each replication and is controlled by an immune system (a so-called 'antivirus') to prevent the explosive growth of the virus population. The viruses are divided into two classes (strong and common) to balance the exploitation and exploration effects. The performance of the VOA is validated through a set of eight benchmark functions, which are also subject to rotation and shifting effects to test its robustness. Extensive comparisons were conducted with over 40 well-known metaheuristic algorithms and their variations, such as artificial bee colony, artificial immune system, differential evolution, evolutionary programming, evolutionary strategy, genetic algorithm, harmony search, invasive weed optimization, memetic algorithm, particle swarm optimization and simulated annealing. The results showed that the VOA is a viable solution for continuous optimization.

Investigation on Covert Channel Attacks and Countermeasures in the Cloud

DTIC Science & Technology

2017-03-29

ahead of the game and continue improving our security systems. Thus, investigating novel attack strategies and tactics is crucial to shaping the...step to stay ahead of the game and continue improving our security systems. Thus, investigating novel attack strategies and tactics is crucial to

Optimal security investments and extreme risk.

PubMed

Mohtadi, Hamid; Agiwal, Swati

2012-08-01

In the aftermath of 9/11, concern over security increased dramatically in both the public and the private sector. Yet, no clear algorithm exists to inform firms on the amount and the timing of security investments to mitigate the impact of catastrophic risks. The goal of this article is to devise an optimum investment strategy for firms to mitigate exposure to catastrophic risks, focusing on how much to invest and when to invest. The latter question addresses the issue of whether postponing a risk mitigating decision is an optimal strategy or not. Accordingly, we develop and estimate both a one-period model and a multiperiod model within the framework of extreme value theory (EVT). We calibrate these models using probability measures for catastrophic terrorism risks associated with attacks on the food sector. We then compare our findings with the purchase of catastrophic risk insurance. © 2012 Society for Risk Analysis.

Modeling Cyber Conflicts Using an Extended Petri Net Formalism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zakrzewska, Anita N; Ferragut, Erik M

2011-01-01

When threatened by automated attacks, critical systems that require human-controlled responses have difficulty making optimal responses and adapting protections in real- time and may therefore be overwhelmed. Consequently, experts have called for the development of automatic real-time reaction capabilities. However, a technical gap exists in the modeling and analysis of cyber conflicts to automatically understand the repercussions of responses. There is a need for modeling cyber assets that accounts for concurrent behavior, incomplete information, and payoff functions. Furthermore, we address this need by extending the Petri net formalism to allow real-time cyber conflicts to be modeled in a way thatmore » is expressive and concise. This formalism includes transitions controlled by players as well as firing rates attached to transitions. This allows us to model both player actions and factors that are beyond the control of players in real-time. We show that our formalism is able to represent situational aware- ness, concurrent actions, incomplete information and objective functions. These factors make it well-suited to modeling cyber conflicts in a way that allows for useful analysis. MITRE has compiled the Common Attack Pattern Enumera- tion and Classification (CAPEC), an extensive list of cyber attacks at various levels of abstraction. CAPEC includes factors such as attack prerequisites, possible countermeasures, and attack goals. These elements are vital to understanding cyber attacks and to generating the corresponding real-time responses. We demonstrate that the formalism can be used to extract precise models of cyber attacks from CAPEC. Several case studies show that our Petri net formalism is more expressive than other models, such as attack graphs, for modeling cyber conflicts and that it is amenable to exploring cyber strategies.« less

Israeli Adolescents' Coping Strategies in Relation to Terrorist Attacks

ERIC Educational Resources Information Center

Tatar, Moshe; Amram, Sima

2007-01-01

Exposure to terrorism seriously threatens the well-being of children and adolescents. Israeli citizens have witnessed massive ongoing terrorist attacks during the last few years. The present research, conducted among 330 Israeli adolescents, examined coping strategies in relation to terrorist attacks. We found that adolescents utilize more…

Behavioral Modeling of Adversaries with Multiple Objectives in Counterterrorism.

PubMed

Mazicioglu, Dogucan; Merrick, Jason R W

2018-05-01

Attacker/defender models have primarily assumed that each decisionmaker optimizes the cost of the damage inflicted and its economic repercussions from their own perspective. Two streams of recent research have sought to extend such models. One stream suggests that it is more realistic to consider attackers with multiple objectives, but this research has not included the adaption of the terrorist with multiple objectives to defender actions. The other stream builds off experimental studies that show that decisionmakers deviate from optimal rational behavior. In this article, we extend attacker/defender models to incorporate multiple objectives that a terrorist might consider in planning an attack. This includes the tradeoffs that a terrorist might consider and their adaption to defender actions. However, we must also consider experimental evidence of deviations from the rationality assumed in the commonly used expected utility model in determining such adaption. Thus, we model the attacker's behavior using multiattribute prospect theory to account for the attacker's multiple objectives and deviations from rationality. We evaluate our approach by considering an attacker with multiple objectives who wishes to smuggle radioactive material into the United States and a defender who has the option to implement a screening process to hinder the attacker. We discuss the problems with implementing such an approach, but argue that research in this area must continue to avoid misrepresenting terrorist behavior in determining optimal defensive actions. © 2017 Society for Risk Analysis.

Advanced unambiguous state discrimination attack and countermeasure strategy in a practical B92 QKD system

NASA Astrophysics Data System (ADS)

Ko, Heasin; Choi, Byung-Seok; Choe, Joong-Seon; Youn, Chun Ju

2018-01-01

Even though unconditional security of B92 quantum key distribution (QKD) system is based on the assumption of perfect positive-operator-valued measures, practical B92 systems only utilize two projective measurements. Unfortunately, such implementation may degrade the security of the B92 QKD system due to Eve's potential attack exploiting the imperfection of system. In this paper, we propose an advanced attack strategy with an unambiguous state discrimination (USD) measurement which makes practical B92 QKD systems insecure even under a lossless channel. In addition, we propose an effective countermeasure against the advanced USD attack model by monitoring double-click events. We further address a fundamental approach to make the B92 QKD system tolerable to attack strategies with USD measurements using a multi-qubit scheme.

Continuous-variable quantum cryptography with an untrusted relay: Detailed security analysis of the symmetric configuration

NASA Astrophysics Data System (ADS)

Ottaviani, Carlo; Spedalieri, Gaetana; Braunstein, Samuel L.; Pirandola, Stefano

2015-02-01

We consider the continuous-variable protocol of Pirandola et al. [arXiv:1312.4104] where the secret key is established by the measurement of an untrusted relay. In this network protocol, two authorized parties are connected to an untrusted relay by insecure quantum links. Secret correlations are generated by a continuous-variable Bell detection performed on incoming coherent states. In the present work we provide a detailed study of the symmetric configuration, where the relay is midway between the parties. We analyze symmetric eavesdropping strategies against the quantum links explicitly showing that, at fixed transmissivity and thermal noise, two-mode coherent attacks are optimal, manifestly outperforming one-mode collective attacks based on independent entangling cloners. Such an advantage is shown both in terms of security threshold and secret-key rate.

Finite Energy and Bounded Attacks on Control System Sensor Signals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Djouadi, Seddik M; Melin, Alexander M; Ferragut, Erik M

Control system networks are increasingly being connected to enterprise level networks. These connections leave critical industrial controls systems vulnerable to cyber-attacks. Most of the effort in protecting these cyber-physical systems (CPS) has been in securing the networks using information security techniques and protection and reliability concerns at the control system level against random hardware and software failures. However, besides these failures the inability of information security techniques to protect against all intrusions means that the control system must be resilient to various signal attacks for which new analysis and detection methods need to be developed. In this paper, sensor signalmore » attacks are analyzed for observer-based controlled systems. The threat surface for sensor signal attacks is subdivided into denial of service, finite energy, and bounded attacks. In particular, the error signals between states of attack free systems and systems subject to these attacks are quantified. Optimal sensor and actuator signal attacks for the finite and infinite horizon linear quadratic (LQ) control in terms of maximizing the corresponding cost functions are computed. The closed-loop system under optimal signal attacks are provided. Illustrative numerical examples are provided together with an application to a power network with distributed LQ controllers.« less

Flight style optimization in ski jumping on normal, large, and ski flying hills.

PubMed

Jung, Alexander; Staat, Manfred; Müller, Wolfram

2014-02-07

In V-style ski jumping, aerodynamic forces are predominant performance factors and athletes have to solve difficult optimization problems in parts of a second in order to obtain their jump length maximum and to keep the flight stable. Here, a comprehensive set of wind tunnel data was used for optimization studies based on Pontryagin's minimum principle with both the angle of attack α and the body-ski angle β as controls. Various combinations of the constraints αmax and βmin(t) were analyzed in order to compare different optimization strategies. For the computer simulation studies, the Olympic hill profiles in Esto-Sadok, Russia (HS 106m, HS 140m), and in Harrachov, Czech Republic, host of the Ski Flying World Championships 2014 (HS 205m) were used. It is of high importance for ski jumping practice that various aerodynamic strategies, i.e. combinations of α- and β-time courses, can lead to similar jump lengths which enables athletes to win competitions using individual aerodynamic strategies. Optimization results also show that aerodynamic behavior has to be different at different hill sizes (HS). Optimized time courses of α and β using reduced drag and lift areas in order to mimic recent equipment regulations differed only in a negligible way. This indicates that optimization results presented here are not very sensitive to minor changes of the aerodynamic equipment features when similar jump length are obtained by using adequately higher in-run velocities. However, wind tunnel measurements with athletes including take-off and transition to stabilized flight, flight, and landing behavior would enable a more detailed understanding of individual flight style optimization. © 2013 Published by Elsevier Ltd.

Modified Discrete Grey Wolf Optimizer Algorithm for Multilevel Image Thresholding

PubMed Central

Sun, Lijuan; Guo, Jian; Xu, Bin; Li, Shujing

2017-01-01

The computation of image segmentation has become more complicated with the increasing number of thresholds, and the option and application of the thresholds in image thresholding fields have become an NP problem at the same time. The paper puts forward the modified discrete grey wolf optimizer algorithm (MDGWO), which improves on the optimal solution updating mechanism of the search agent by the weights. Taking Kapur's entropy as the optimized function and based on the discreteness of threshold in image segmentation, the paper firstly discretizes the grey wolf optimizer (GWO) and then proposes a new attack strategy by using the weight coefficient to replace the search formula for optimal solution used in the original algorithm. The experimental results show that MDGWO can search out the optimal thresholds efficiently and precisely, which are very close to the result examined by exhaustive searches. In comparison with the electromagnetism optimization (EMO), the differential evolution (DE), the Artifical Bee Colony (ABC), and the classical GWO, it is concluded that MDGWO has advantages over the latter four in terms of image segmentation quality and objective function values and their stability. PMID:28127305

A Defender-Attacker Optimization of Port Radar Surveillance

DTIC Science & Technology

2011-01-01

security; optimization; attacker-defender “And thence discover how with most advantage They may vex us with shot, or with assault.” Shakespeare , KingHenryVI...ed., McGraw-Hill, New York, 1990. [23] H. von Stackelberg, The theory of the market economy, William Hodge, London, UK, 1952. [24] J. Benders

Stealthy false data injection attacks using matrix recovery and independent component analysis in smart grid

NASA Astrophysics Data System (ADS)

JiWei, Tian; BuHong, Wang; FuTe, Shang; Shuaiqi, Liu

2017-05-01

Exact state estimation is vital important to maintain common operations of smart grids. Existing researches demonstrate that state estimation output could be compromised by malicious attacks. However, to construct the attack vectors, a usual presumption in most works is that the attacker has perfect information regarding the topology and so on even such information is difficult to acquire in practice. Recent research shows that Independent Component Analysis (ICA) can be used for inferring topology information which can be used to originate undetectable attacks and even to alter the price of electricity for the profits of attackers. However, we found that the above ICA-based blind attack tactics is merely feasible in the environment with Gaussian noises. If there are outliers (device malfunction and communication errors), the Bad Data Detector will easily detect the attack. Hence, we propose a robust ICA based blind attack strategy that one can use matrix recovery to circumvent the outlier problem and construct stealthy attack vectors. The proposed attack strategies are tested with IEEE representative 14-bus system. Simulations verify the feasibility of the proposed method.

Catastrophizing, rumination, and reappraisal prospectively predict adolescent PTSD symptom onset following a terrorist attack

PubMed Central

Jenness, Jessica L.; Jager-Hyman, Shari; Heleniak, Charlotte; Beck, Aaron T.; Sheridan, Margaret A.; McLaughlin, Katie A.

2016-01-01

Background Disruptions in emotion regulation are a transdiagnostic risk factor for psychopathology. However, scant research has examined whether emotion regulation strategies are related to the onset of posttraumatic stress disorder (PTSD) symptoms among youths exposed to trauma. We investigated whether pretrauma emotion regulation strategies prospectively predicted PTSD symptom onset after the 2013 Boston Marathon terrorist attack among adolescents and whether these associations were moderated by the degree of exposure to media coverage of the attack. Methods A sample of 78 Boston-area adolescents (mean age =16.72 years, 65% female) who previously participated in studies assessing emotion regulation and psychopathology were recruited following the terrorist attack. Within 4 weeks of the attack, we assessed self-reported PTSD symptoms and attack-related media exposure via an online survey. We examined the association of pretrauma emotion regulation strategies with PTSD symptom onset after adjustment for pretrauma internalizing symptoms and violence exposure. Results Greater pretrauma engagement in rumination predicted onset of PTSD symptoms following the attack. Adolescents who engaged in catastrophizing also had greater PTSD symptoms postattack, but only when exposed to high levels of media coverage of the attacks; the same pattern was observed for adolescents who engaged in low levels of cognitive reappraisal. Conclusions Engagement in specific emotion regulation strategies prior to a traumatic event predicts the onset of PTSD symptoms among youths exposed to trauma, extending transdiagnostic models of emotion regulation to encompass trauma-related psychopathology in children and adolescents. PMID:27557454

A Learning-Based Approach to Reactive Security

NASA Astrophysics Data System (ADS)

Barth, Adam; Rubinstein, Benjamin I. P.; Sundararajan, Mukund; Mitchell, John C.; Song, Dawn; Bartlett, Peter L.

Despite the conventional wisdom that proactive security is superior to reactive security, we show that reactive security can be competitive with proactive security as long as the reactive defender learns from past attacks instead of myopically overreacting to the last attack. Our game-theoretic model follows common practice in the security literature by making worst-case assumptions about the attacker: we grant the attacker complete knowledge of the defender's strategy and do not require the attacker to act rationally. In this model, we bound the competitive ratio between a reactive defense algorithm (which is inspired by online learning theory) and the best fixed proactive defense. Additionally, we show that, unlike proactive defenses, this reactive strategy is robust to a lack of information about the attacker's incentives and knowledge.

Optimality of Gaussian attacks in continuous-variable quantum cryptography.

PubMed

Navascués, Miguel; Grosshans, Frédéric; Acín, Antonio

2006-11-10

We analyze the asymptotic security of the family of Gaussian modulated quantum key distribution protocols for continuous-variables systems. We prove that the Gaussian unitary attack is optimal for all the considered bounds on the key rate when the first and second momenta of the canonical variables involved are known by the honest parties.

Modelling radicalization: how small violent fringe sects develop into large indoctrinated societies

PubMed Central

2017-01-01

We model radicalization in a society consisting of two competing religious, ethnic or political groups. Each of the ‘sects’ is divided into moderate and radical factions, with intra-group transitions occurring either spontaneously or through indoctrination. We also include the possibility of one group violently attacking the other. The intra-group transition rates of one group are modelled to explicitly depend on the actions and characteristics of the other, including violent episodes, effectively coupling the dynamics of the two sects. We use a game theoretic framework and assume that radical factions may tune ‘strategic’ parameters to optimize given utility functions aimed at maximizing their ranks while minimizing the damage inflicted by their rivals. Constraints include limited overall resources that must be optimally allocated between indoctrination and external attacks on the other group. Various scenarios are considered, from symmetric sects whose behaviours mirror each other, to totally asymmetric ones where one sect may have a larger population or a superior resource availability. We discuss under what conditions sects preferentially employ indoctrination or violence, and how allowing sects to readjust their strategies allows for small, violent sects to grow into large, indoctrinated communities. PMID:28879010

Modelling radicalization: how small violent fringe sects develop into large indoctrinated societies

NASA Astrophysics Data System (ADS)

Short, Martin B.; McCalla, Scott G.; D'Orsogna, Maria R.

2017-08-01

We model radicalization in a society consisting of two competing religious, ethnic or political groups. Each of the `sects' is divided into moderate and radical factions, with intra-group transitions occurring either spontaneously or through indoctrination. We also include the possibility of one group violently attacking the other. The intra-group transition rates of one group are modelled to explicitly depend on the actions and characteristics of the other, including violent episodes, effectively coupling the dynamics of the two sects. We use a game theoretic framework and assume that radical factions may tune `strategic' parameters to optimize given utility functions aimed at maximizing their ranks while minimizing the damage inflicted by their rivals. Constraints include limited overall resources that must be optimally allocated between indoctrination and external attacks on the other group. Various scenarios are considered, from symmetric sects whose behaviours mirror each other, to totally asymmetric ones where one sect may have a larger population or a superior resource availability. We discuss under what conditions sects preferentially employ indoctrination or violence, and how allowing sects to readjust their strategies allows for small, violent sects to grow into large, indoctrinated communities.

Continuous-variable quantum cryptography is secure against non-Gaussian attacks.

PubMed

Grosshans, Frédéric; Cerf, Nicolas J

2004-01-30

A general study of arbitrary finite-size coherent attacks against continuous-variable quantum cryptographic schemes is presented. It is shown that, if the size of the blocks that can be coherently attacked by an eavesdropper is fixed and much smaller than the key size, then the optimal attack for a given signal-to-noise ratio in the transmission line is an individual Gaussian attack. Consequently, non-Gaussian coherent attacks do not need to be considered in the security analysis of such quantum cryptosystems.

Angle of Attack Modulation for Mars Entry Terminal State Optimization

NASA Technical Reports Server (NTRS)

Lafleur, Jarret M.; Cerimele, Christopher J.

2009-01-01

From the perspective of atmospheric entry, descent, and landing (EDL), one of the most foreboding destinations in the solar system is Mars due in part to its exceedingly thin atmosphere. To benchmark best possible scenarios for evaluation of potential Mars EDL system designs, a study is conducted to optimize the entry-to-terminal-state portion of EDL for a variety of entry velocities and vehicle masses, focusing on the identification of potential benefits of enabling angle of attack modulation. The terminal state is envisioned as one appropriate for the initiation of terminal descent via parachute or other means. A particle swarm optimizer varies entry flight path angle, ten bank profile points, and ten angle of attack profile points to find maximum-final-altitude trajectories for a 10 30 m ellipsled at 180 different combinations of values for entry mass, entry velocity, terminal Mach number, and minimum allowable altitude. Parametric plots of maximum achievable altitude are shown, as are examples of optimized trajectories. It is shown that appreciable terminal state altitude gains (2.5-4.0 km) over pure bank angle control may be possible if angle of attack modulation is enabled for Mars entry vehicles. Gains of this magnitude could prove to be enabling for missions requiring high-altitude landing sites. Conclusions are also drawn regarding trends in the bank and angle of attack profiles that produce the optimal trajectories in this study, and directions for future work are identified.

Does topological information matter for power grid vulnerability?

PubMed

Ouyang, Min; Yang, Kun

2014-12-01

Power grids, which are playing an important role in supporting the economy of a region as well as the life of its citizens, could be attacked by terrorists or enemies to damage the region. Depending on different levels of power grid information collected by the terrorists, their attack strategies might be different. This paper groups power grid information into four levels: no information, purely topological information (PTI), topological information with generator and load nodes (GLNI), and full information (including component physical properties and flow parameters information), and then identifies possible attack strategies for each information level. Analyzing and comparing power grid vulnerability under these attack strategies from both terrorists' and utility companies' point of view give rise to an approach to quantify the relative values of these three types of information, including PTI, GLNI, and component parameter information (CPI). This approach can provide information regarding the extent to which topological information matters for power system vulnerability decisions. Taking several test systems as examples, results show that for small attacks with p ≤ 0.1, CPI matters the most; when taking attack cost into consideration and assuming that the terrorists take the optimum cost-efficient attack intensity, then CPI has the largest cost-based information value.

Does topological information matter for power grid vulnerability?

NASA Astrophysics Data System (ADS)

Ouyang, Min; Yang, Kun

2014-12-01

Power grids, which are playing an important role in supporting the economy of a region as well as the life of its citizens, could be attacked by terrorists or enemies to damage the region. Depending on different levels of power grid information collected by the terrorists, their attack strategies might be different. This paper groups power grid information into four levels: no information, purely topological information (PTI), topological information with generator and load nodes (GLNI), and full information (including component physical properties and flow parameters information), and then identifies possible attack strategies for each information level. Analyzing and comparing power grid vulnerability under these attack strategies from both terrorists' and utility companies' point of view give rise to an approach to quantify the relative values of these three types of information, including PTI, GLNI, and component parameter information (CPI). This approach can provide information regarding the extent to which topological information matters for power system vulnerability decisions. Taking several test systems as examples, results show that for small attacks with p ≤ 0.1, CPI matters the most; when taking attack cost into consideration and assuming that the terrorists take the optimum cost-efficient attack intensity, then CPI has the largest cost-based information value.

Measure of robustness for complex networks

NASA Astrophysics Data System (ADS)

Youssef, Mina Nabil

Critical infrastructures are repeatedly attacked by external triggers causing tremendous amount of damages. Any infrastructure can be studied using the powerful theory of complex networks. A complex network is composed of extremely large number of different elements that exchange commodities providing significant services. The main functions of complex networks can be damaged by different types of attacks and failures that degrade the network performance. These attacks and failures are considered as disturbing dynamics, such as the spread of viruses in computer networks, the spread of epidemics in social networks, and the cascading failures in power grids. Depending on the network structure and the attack strength, every network differently suffers damages and performance degradation. Hence, quantifying the robustness of complex networks becomes an essential task. In this dissertation, new metrics are introduced to measure the robustness of technological and social networks with respect to the spread of epidemics, and the robustness of power grids with respect to cascading failures. First, we introduce a new metric called the Viral Conductance (VCSIS ) to assess the robustness of networks with respect to the spread of epidemics that are modeled through the susceptible/infected/susceptible (SIS) epidemic approach. In contrast to assessing the robustness of networks based on a classical metric, the epidemic threshold, the new metric integrates the fraction of infected nodes at steady state for all possible effective infection strengths. Through examples, VCSIS provides more insights about the robustness of networks than the epidemic threshold. In addition, both the paradoxical robustness of Barabasi-Albert preferential attachment networks and the effect of the topology on the steady state infection are studied, to show the importance of quantifying the robustness of networks. Second, a new metric VCSIR is introduced to assess the robustness of networks with respect to the spread of susceptible/infected/recovered (SIR) epidemics. To compute VCSIR, we propose a novel individual-based approach to model the spread of SIR epidemics in networks, which captures the infection size for a given effective infection rate. Thus, VCSIR quantitatively integrates the infection strength with the corresponding infection size. To optimize the VCSIR metric, a new mitigation strategy is proposed, based on a temporary reduction of contacts in social networks. The social contact network is modeled as a weighted graph that describes the frequency of contacts among the individuals. Thus, we consider the spread of an epidemic as a dynamical system, and the total number of infection cases as the state of the system, while the weight reduction in the social network is the controller variable leading to slow/reduce the spread of epidemics. Using optimal control theory, the obtained solution represents an optimal adaptive weighted network defined over a finite time interval. Moreover, given the high complexity of the optimization problem, we propose two heuristics to find the near optimal solutions by reducing the contacts among the individuals in a decentralized way. Finally, the cascading failures that can take place in power grids and have recently caused several blackouts are studied. We propose a new metric to assess the robustness of the power grid with respect to the cascading failures. The power grid topology is modeled as a network, which consists of nodes and links representing power substations and transmission lines, respectively. We also propose an optimal islanding strategy to protect the power grid when a cascading failure event takes place in the grid. The robustness metrics are numerically evaluated using real and synthetic networks to quantify their robustness with respect to disturbing dynamics. We show that the proposed metrics outperform the classical metrics in quantifying the robustness of networks and the efficiency of the mitigation strategies. In summary, our work advances the network science field in assessing the robustness of complex networks with respect to various disturbing dynamics.

Data mining for multiagent rules, strategies, and fuzzy decision tree structure

NASA Astrophysics Data System (ADS)

Smith, James F., III; Rhyne, Robert D., II; Fisher, Kristin

2002-03-01

A fuzzy logic based resource manager (RM) has been developed that automatically allocates electronic attack resources in real-time over many dissimilar platforms. Two different data mining algorithms have been developed to determine rules, strategies, and fuzzy decision tree structure. The first data mining algorithm uses a genetic algorithm as a data mining function and is called from an electronic game. The game allows a human expert to play against the resource manager in a simulated battlespace with each of the defending platforms being exclusively directed by the fuzzy resource manager and the attacking platforms being controlled by the human expert or operating autonomously under their own logic. This approach automates the data mining problem. The game automatically creates a database reflecting the domain expert's knowledge. It calls a data mining function, a genetic algorithm, for data mining of the database as required and allows easy evaluation of the information mined in the second step. The criterion for re- optimization is discussed as well as experimental results. Then a second data mining algorithm that uses a genetic program as a data mining function is introduced to automatically discover fuzzy decision tree structures. Finally, a fuzzy decision tree generated through this process is discussed.

A U.S. Biodefense Strategy Primer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poulin, D

2009-05-11

The anthrax mailings that followed the attacks of September 11, 2001 highlighted the need for a comprehensive national strategy to prevent, prepare for, respond to, and mitigate the effects of biological attacks. The goal of U.S. biodefense strategy is to reduce the likelihood of a future biological event, improve overall U.S. public health security, and minimize the economic and social disruption of a biological incident. Presidential communications, federal legislation, and executive agency planning documents provide the foundation for this strategy. Central to current U.S. biodefense strategy is the 2004 Homeland Security Presidential Directive (HSPD) 10, Biodefense for the 21st Century,more » which states that ''the United States will use all means necessary to prevent, protect against, and mitigate biological weapons attacks perpetrated against our homeland and our global interests.'' HSPD-10 also sets forth four pillars of U.S. biodefense: {sm_bullet} Threat awareness includes timely, accurate, and relevant intelligence, threat assessment, and the anticipation of future threats. {sm_bullet} Prevention and protection involve continuing and expanding efforts to limit access to agents, technologies, and knowledge to certain groups and countries as well as protecting critical infrastructure from the effects of biological attacks. {sm_bullet} Surveillance and detection provide early warning or recognition of biological attacks to permit a timely response and mitigation of consequences as well as attribution. {sm_bullet} Response and recovery include pre-attack planning and preparedness, capabilities to treat casualties, risk communications, physical control measures, medical countermeasures, and decontamination capabilities.« less

Heart attack risk perception biases among hypertension patients: the role of educational level and worry.

PubMed

Peterson, Laurel M; Helweg-Larsen, Marie; Volpp, Kevin G; Kimmel, Stephen E

2012-01-01

Risk biases such as comparative optimism (thinking one is better off than similar others) and risk inaccuracy (misestimating one's risk compared to one's calculated risk) for health outcomes are common. Little research has investigated racial or socioeconomic differences in these risk biases. Results from a survey of individuals with poorly controlled hypertension (N=813) indicated that participants showed (1) comparative optimism for heart attack risk by underestimating their heart attack risk compared to similar others, and (2) risk inaccuracy by overestimating their heart attack risk compared to their calculated heart attack risk. More highly educated participants were more comparatively optimistic because they rated their personal risk as lower; education was not related to risk inaccuracy. Neither race nor the federal poverty level was related to risk biases. Worry partially mediated the relationship between education and personal risk. Results are discussed as they relate to the existing literature on risk perception.

A Taxonomy of Attacks on the DNP3 Protocol

NASA Astrophysics Data System (ADS)

East, Samuel; Butts, Jonathan; Papa, Mauricio; Shenoi, Sujeet

Distributed Network Protocol (DNP3) is the predominant SCADA protocol in the energy sector - more than 75% of North American electric utilities currently use DNP3 for industrial control applications. This paper presents a taxonomy of attacks on the protocol. The attacks are classified based on targets (control center, outstation devices and network/communication paths) and threat categories (interception, interruption, modification and fabrication). To facilitate risk analysis and mitigation strategies, the attacks are associated with the specific DNP3 protocol layers they exploit. Also, the operational impact of the attacks is categorized in terms of three key SCADA objectives: process confi- dentiality, process awareness and process control. The attack taxonomy clarifies the nature and scope of the threats to DNP3 systems, and can provide insights into the relative costs and benefits of implementing mitigation strategies.

Comparison of artificial intelligence classifiers for SIP attack data

NASA Astrophysics Data System (ADS)

Safarik, Jakub; Slachta, Jiri

2016-05-01

Honeypot application is a source of valuable data about attacks on the network. We run several SIP honeypots in various computer networks, which are separated geographically and logically. Each honeypot runs on public IP address and uses standard SIP PBX ports. All information gathered via honeypot is periodically sent to the centralized server. This server classifies all attack data by neural network algorithm. The paper describes optimizations of a neural network classifier, which lower the classification error. The article contains the comparison of two neural network algorithm used for the classification of validation data. The first is the original implementation of the neural network described in recent work; the second neural network uses further optimizations like input normalization or cross-entropy cost function. We also use other implementations of neural networks and machine learning classification algorithms. The comparison test their capabilities on validation data to find the optimal classifier. The article result shows promise for further development of an accurate SIP attack classification engine.

Mountain pine beetle detection and monitoring: evaluation of airborne imagery

NASA Astrophysics Data System (ADS)

Roberts, A.; Bone, C.; Dragicevic, S.; Ettya, A.; Northrup, J.; Reich, R.

2007-10-01

The processing and evaluation of digital airborne imagery for detection, monitoring and modeling of mountain pine beetle (MPB) infestations is evaluated. The most efficient and reliable remote sensing strategy for identification and mapping of infestation stages ("current" to "red" to "grey" attack) of MPB in lodgepole pine forests is determined for the most practical and cost effective procedures. This research was planned to specifically enhance knowledge by determining the remote sensing imaging systems and analytical procedures that optimize resource management for this critical forest health problem. Within the context of this study, airborne remote sensing of forest environments for forest health determinations (MPB) is most suitably undertaken using multispectral digitally converted imagery (aerial photography) at scales of 1:8000 for early detection of current MPB attack and 1:16000 for mapping and sequential monitoring of red and grey attack. Digital conversion should be undertaken at 10 to 16 microns for B&W multispectral imagery and 16 to 24 microns for colour and colour infrared imagery. From an "operational" perspective, the use of twin mapping-cameras with colour and B&W or colour infrared film will provide the best approximation of multispectral digital imagery with near comparable performance in a competitive private sector context (open bidding).

Critical Infrastructure Protection: EMP Impacts on the U.S. Electric Grid

NASA Astrophysics Data System (ADS)

Boston, Edwin J., Jr.

The purpose of this research is to identify the United States electric grid infrastructure systems vulnerabilities to electromagnetic pulse attacks and the cyber-based impacts of those vulnerabilities to the electric grid. Additionally, the research identifies multiple defensive strategies designed to harden the electric grid against electromagnetic pulse attack that include prevention, mitigation and recovery postures. Research results confirm the importance of the electric grid to the United States critical infrastructures system and that an electromagnetic pulse attack against the electric grid could result in electric grid degradation, critical infrastructure(s) damage and the potential for societal collapse. The conclusions of this research indicate that while an electromagnetic pulse attack against the United States electric grid could have catastrophic impacts on American society, there are currently many defensive strategies under consideration designed to prevent, mitigate and or recover from an electromagnetic pulse attack. However, additional research is essential to further identify future target hardening opportunities, efficient implementation strategies and funding resources.

Deploying initial attack resources for wildfire suppression: spatial coordination, budget constraints, and capacity constraints

Treesearch

Yohan Lee; Jeremy S. Fried; Heidi J. Albers; Robert G. Haight

2013-01-01

We combine a scenario-based, standard-response optimization model with stochastic simulation to improve the efficiency of resource deployment for initial attack on wildland fires in three planning units in California. The optimization model minimizes the expected number of fires that do not receive a standard response--defined as the number of resources by type that...

Herbivore-mediated ecological costs of reproduction shape the life history of an iteroparous plant.

PubMed

Miller, Tom E X; Tenhumberg, Brigitte; Louda, Svata M

2008-02-01

Plant reproduction yields immediate fitness benefits but can be costly in terms of survival, growth, and future fecundity. Life-history theory posits that reproductive strategies are shaped by trade-offs between current and future fitness that result from these direct costs of reproduction. Plant reproduction may also incur indirect ecological costs if it increases susceptibility to herbivores. Yet ecological costs of reproduction have received little empirical attention and remain poorly integrated into life-history theory. Here, we provide evidence for herbivore-mediated ecological costs of reproduction, and we develop theory to examine how these costs influence plant life-history strategies. Field experiments with an iteroparous cactus (Opuntia imbricata) indicated that greater reproductive effort (proportion of meristems allocated to reproduction) led to greater attack by a cactus-feeding insect (Narnia pallidicornis) and that damage by this herbivore reduced reproductive success. A dynamic programming model predicted strongly divergent optimal reproductive strategies when ecological costs were included, compared with when these costs were ignored. Meristem allocation by cacti in the field matched the optimal strategy expected under ecological costs of reproduction. The results indicate that plant reproductive allocation can strongly influence the intensity of interactions with herbivores and that associated ecological costs can play an important selective role in the evolution of plant life histories.

Towards an Iterated Game Model with Multiple Adversaries in Smart-World Systems.

PubMed

He, Xiaofei; Yang, Xinyu; Yu, Wei; Lin, Jie; Yang, Qingyu

2018-02-24

Diverse and varied cyber-attacks challenge the operation of the smart-world system that is supported by Internet-of-Things (IoT) (smart cities, smart grid, smart transportation, etc.) and must be carefully and thoughtfully addressed before widespread adoption of the smart-world system can be fully realized. Although a number of research efforts have been devoted to defending against these threats, a majority of existing schemes focus on the development of a specific defensive strategy to deal with specific, often singular threats. In this paper, we address the issue of coalitional attacks, which can be launched by multiple adversaries cooperatively against the smart-world system such as smart cities. Particularly, we propose a game-theory based model to capture the interaction among multiple adversaries, and quantify the capacity of the defender based on the extended Iterated Public Goods Game (IPGG) model. In the formalized game model, in each round of the attack, a participant can either cooperate by participating in the coalitional attack, or defect by standing aside. In our work, we consider the generic defensive strategy that has a probability to detect the coalitional attack. When the coalitional attack is detected, all participating adversaries are penalized. The expected payoff of each participant is derived through the equalizer strategy that provides participants with competitive benefits. The multiple adversaries with the collusive strategy are also considered. Via a combination of theoretical analysis and experimentation, our results show that no matter which strategies the adversaries choose (random strategy, win-stay-lose-shift strategy, or even the adaptive equalizer strategy), our formalized game model is capable of enabling the defender to greatly reduce the maximum value of the expected average payoff to the adversaries via provisioning sufficient defensive resources, which is reflected by setting a proper penalty factor against the adversaries. In addition, we extend our game model and analyze the extortion strategy, which can enable one participant to obtain more payoff by extorting his/her opponents. The evaluation results show that the defender can combat this strategy by encouraging competition among the adversaries, and significantly suppress the total payoff of the adversaries via setting the proper penalty factor.

Towards an Iterated Game Model with Multiple Adversaries in Smart-World Systems †

PubMed Central

Yang, Xinyu; Yu, Wei; Lin, Jie; Yang, Qingyu

2018-01-01

Diverse and varied cyber-attacks challenge the operation of the smart-world system that is supported by Internet-of-Things (IoT) (smart cities, smart grid, smart transportation, etc.) and must be carefully and thoughtfully addressed before widespread adoption of the smart-world system can be fully realized. Although a number of research efforts have been devoted to defending against these threats, a majority of existing schemes focus on the development of a specific defensive strategy to deal with specific, often singular threats. In this paper, we address the issue of coalitional attacks, which can be launched by multiple adversaries cooperatively against the smart-world system such as smart cities. Particularly, we propose a game-theory based model to capture the interaction among multiple adversaries, and quantify the capacity of the defender based on the extended Iterated Public Goods Game (IPGG) model. In the formalized game model, in each round of the attack, a participant can either cooperate by participating in the coalitional attack, or defect by standing aside. In our work, we consider the generic defensive strategy that has a probability to detect the coalitional attack. When the coalitional attack is detected, all participating adversaries are penalized. The expected payoff of each participant is derived through the equalizer strategy that provides participants with competitive benefits. The multiple adversaries with the collusive strategy are also considered. Via a combination of theoretical analysis and experimentation, our results show that no matter which strategies the adversaries choose (random strategy, win-stay-lose-shift strategy, or even the adaptive equalizer strategy), our formalized game model is capable of enabling the defender to greatly reduce the maximum value of the expected average payoff to the adversaries via provisioning sufficient defensive resources, which is reflected by setting a proper penalty factor against the adversaries. In addition, we extend our game model and analyze the extortion strategy, which can enable one participant to obtain more payoff by extorting his/her opponents. The evaluation results show that the defender can combat this strategy by encouraging competition among the adversaries, and significantly suppress the total payoff of the adversaries via setting the proper penalty factor. PMID:29495291

Method and tool for network vulnerability analysis

DOEpatents

Swiler, Laura Painton [Albuquerque, NM; Phillips, Cynthia A [Albuquerque, NM

2006-03-14

A computer system analysis tool and method that will allow for qualitative and quantitative assessment of security attributes and vulnerabilities in systems including computer networks. The invention is based on generation of attack graphs wherein each node represents a possible attack state and each edge represents a change in state caused by a single action taken by an attacker or unwitting assistant. Edges are weighted using metrics such as attacker effort, likelihood of attack success, or time to succeed. Generation of an attack graph is accomplished by matching information about attack requirements (specified in "attack templates") to information about computer system configuration (contained in a configuration file that can be updated to reflect system changes occurring during the course of an attack) and assumed attacker capabilities (reflected in "attacker profiles"). High risk attack paths, which correspond to those considered suited to application of attack countermeasures given limited resources for applying countermeasures, are identified by finding "epsilon optimal paths."

Robustness of Controllability for Networks Based on Edge-Attack

PubMed Central

Nie, Sen; Wang, Xuwen; Zhang, Haifeng; Li, Qilang; Wang, Binghong

2014-01-01

We study the controllability of networks in the process of cascading failures under two different attacking strategies, random and intentional attack, respectively. For the highest-load edge attack, it is found that the controllability of Erdős-Rényi network, that with moderate average degree, is less robust, whereas the Scale-free network with moderate power-law exponent shows strong robustness of controllability under the same attack strategy. The vulnerability of controllability under random and intentional attacks behave differently with the increasing of removal fraction, especially, we find that the robustness of control has important role in cascades for large removal fraction. The simulation results show that for Scale-free networks with various power-law exponents, the network has larger scale of cascades do not mean that there will be more increments of driver nodes. Meanwhile, the number of driver nodes in cascading failures is also related to the edges amount in strongly connected components. PMID:24586507

Robustness of controllability for networks based on edge-attack.

PubMed

Nie, Sen; Wang, Xuwen; Zhang, Haifeng; Li, Qilang; Wang, Binghong

2014-01-01

We study the controllability of networks in the process of cascading failures under two different attacking strategies, random and intentional attack, respectively. For the highest-load edge attack, it is found that the controllability of Erdős-Rényi network, that with moderate average degree, is less robust, whereas the Scale-free network with moderate power-law exponent shows strong robustness of controllability under the same attack strategy. The vulnerability of controllability under random and intentional attacks behave differently with the increasing of removal fraction, especially, we find that the robustness of control has important role in cascades for large removal fraction. The simulation results show that for Scale-free networks with various power-law exponents, the network has larger scale of cascades do not mean that there will be more increments of driver nodes. Meanwhile, the number of driver nodes in cascading failures is also related to the edges amount in strongly connected components.

Experimental implementation of non-Gaussian attacks on a continuous-variable quantum-key-distribution system.

PubMed

Lodewyck, Jérôme; Debuisschert, Thierry; García-Patrón, Raúl; Tualle-Brouri, Rosa; Cerf, Nicolas J; Grangier, Philippe

2007-01-19

An intercept-resend attack on a continuous-variable quantum-key-distribution protocol is investigated experimentally. By varying the interception fraction, one can implement a family of attacks where the eavesdropper totally controls the channel parameters. In general, such attacks add excess noise in the channel, and may also result in non-Gaussian output distributions. We implement and characterize the measurements needed to detect these attacks, and evaluate experimentally the information rates available to the legitimate users and the eavesdropper. The results are consistent with the optimality of Gaussian attacks resulting from the security proofs.

On the optimality of individual entangling-probe attacks against BB84 quantum key distribution

NASA Astrophysics Data System (ADS)

Herbauts, I. M.; Bettelli, S.; Hã¼bel, H.; Peev, M.

2008-02-01

Some MIT researchers [Phys. Rev. A 75, 042327 (2007)] have recently claimed that their implementation of the Slutsky-Brandt attack [Phys. Rev. A 57, 2383 (1998); Phys. Rev. A 71, 042312 (2005)] to the BB84 quantum-key-distribution (QKD) protocol puts the security of this protocol “to the test” by simulating “the most powerful individual-photon attack” [Phys. Rev. A 73, 012315 (2006)]. A related unfortunate news feature by a scientific journal [G. Brumfiel, Quantum cryptography is hacked, News @ Nature (april 2007); Nature 447, 372 (2007)] has spurred some concern in the QKD community and among the general public by misinterpreting the implications of this work. The present article proves the existence of a stronger individual attack on QKD protocols with encrypted error correction, for which tight bounds are shown, and clarifies why the claims of the news feature incorrectly suggest a contradiction with the established “old-style” theory of BB84 individual attacks. The full implementation of a quantum cryptographic protocol includes a reconciliation and a privacy-amplification stage, whose choice alters in general both the maximum extractable secret and the optimal eavesdropping attack. The authors of [Phys. Rev. A 75, 042327 (2007)] are concerned only with the error-free part of the so-called sifted string, and do not consider faulty bits, which, in the version of their protocol, are discarded. When using the provably superior reconciliation approach of encrypted error correction (instead of error discard), the Slutsky-Brandt attack is no more optimal and does not “threaten” the security bound derived by Lütkenhaus [Phys. Rev. A 59, 3301 (1999)]. It is shown that the method of Slutsky and collaborators [Phys. Rev. A 57, 2383 (1998)] can be adapted to reconciliation with error correction, and that the optimal entangling probe can be explicitly found. Moreover, this attack fills Lütkenhaus bound, proving that it is tight (a fact which was not previously known).

Randomized Prediction Games for Adversarial Machine Learning.

PubMed

Rota Bulo, Samuel; Biggio, Battista; Pillai, Ignazio; Pelillo, Marcello; Roli, Fabio

In spam and malware detection, attackers exploit randomization to obfuscate malicious data and increase their chances of evading detection at test time, e.g., malware code is typically obfuscated using random strings or byte sequences to hide known exploits. Interestingly, randomization has also been proposed to improve security of learning algorithms against evasion attacks, as it results in hiding information about the classifier to the attacker. Recent work has proposed game-theoretical formulations to learn secure classifiers, by simulating different evasion attacks and modifying the classification function accordingly. However, both the classification function and the simulated data manipulations have been modeled in a deterministic manner, without accounting for any form of randomization. In this paper, we overcome this limitation by proposing a randomized prediction game, namely, a noncooperative game-theoretic formulation in which the classifier and the attacker make randomized strategy selections according to some probability distribution defined over the respective strategy set. We show that our approach allows one to improve the tradeoff between attack detection and false alarms with respect to the state-of-the-art secure classifiers, even against attacks that are different from those hypothesized during design, on application examples including handwritten digit recognition, spam, and malware detection.In spam and malware detection, attackers exploit randomization to obfuscate malicious data and increase their chances of evading detection at test time, e.g., malware code is typically obfuscated using random strings or byte sequences to hide known exploits. Interestingly, randomization has also been proposed to improve security of learning algorithms against evasion attacks, as it results in hiding information about the classifier to the attacker. Recent work has proposed game-theoretical formulations to learn secure classifiers, by simulating different evasion attacks and modifying the classification function accordingly. However, both the classification function and the simulated data manipulations have been modeled in a deterministic manner, without accounting for any form of randomization. In this paper, we overcome this limitation by proposing a randomized prediction game, namely, a noncooperative game-theoretic formulation in which the classifier and the attacker make randomized strategy selections according to some probability distribution defined over the respective strategy set. We show that our approach allows one to improve the tradeoff between attack detection and false alarms with respect to the state-of-the-art secure classifiers, even against attacks that are different from those hypothesized during design, on application examples including handwritten digit recognition, spam, and malware detection.

Self-Regulated Assignment Attack Strategy: Evaluating the Effects of a Classroom-Level Intervention on Student Management of Curricular Activities in a Resource Context

ERIC Educational Resources Information Center

Ness, Bryan M.; Sohlberg, McKay Moore

2013-01-01

The purpose of this study was to evaluate the impact of a classroom-based strategy instruction package grounded in self-regulated learning. The Self-Regulated Assignment Attack Strategy (SAAS) targeted self-regulation of assignment management and related academic-behavioral variables for 6th grade students in resource support classrooms. SAAS was…

LG-ANALYST: linguistic geometry for master air attack planning

NASA Astrophysics Data System (ADS)

Stilman, Boris; Yakhnis, Vladimir; Umanskiy, Oleg

2003-09-01

We investigate the technical feasibility of implementing LG-ANALYST, a new software tool based on the Linguistic Geometry (LG) approach. The tool will be capable of modeling and providing solutions to Air Force related battlefield problems and of conducting multiple experiments to verify the quality of the solutions it generates. LG-ANALYST will support generation of the Fast Master Air Attack Plan (MAAP) with subsequent conversion into Air Tasking Order (ATO). An Air Force mission is modeled employing abstract board games (ABG). Such a mission may include, for example, an aircraft strike package moving to a target area with the opposing side having ground-to-air missiles, anti-aircraft batteries, fighter wings, and radars. The corresponding abstract board captures 3D air space, terrain, the aircraft trajectories, positions of the batteries, strategic features of the terrain, such as bridges, and their status, radars and illuminated space, etc. Various animated views are provided by LG-ANALYST including a 3D view for realistic representation of the battlespace and a 2D view for ease of analysis and control. LG-ANALYST will allow a user to model full scale intelligent enemy, plan in advance, re-plan and control in real time Blue and Red forces by generating optimal (or near-optimal) strategies for all sides of a conflict.

Assessment and Intervention for Academic Task Attack Strategy Competencies

ERIC Educational Resources Information Center

Busse, R. T.; Lee, Charlene

2015-01-01

Many students who underachieve in schools may not be learning as effectively as they could. Direct assessments such as the Academic Competence Evaluation Scales (ACES), School Motivation and Learning Strategies Inventory (SMALSI), and the Academic Task Attack Checklist System (ATACS) can be used to evaluate students' knowledge and use of…

Formulating a strategy for securing high-speed rail in the United States.

DOT National Transportation Integrated Search

2013-03-01

This report presents an analysis of information relating to attacks, attempted attacks, and plots against high-speed rail (HSR) : systems. It draws upon empirical data from MTIs Database of Terrorist and Serious Criminal Attacks Against Public Sur...

Attack Vulnerability of Network Controllability

PubMed Central

2016-01-01

Controllability of complex networks has attracted much attention, and understanding the robustness of network controllability against potential attacks and failures is of practical significance. In this paper, we systematically investigate the attack vulnerability of network controllability for the canonical model networks as well as the real-world networks subject to attacks on nodes and edges. The attack strategies are selected based on degree and betweenness centralities calculated for either the initial network or the current network during the removal, among which random failure is as a comparison. It is found that the node-based strategies are often more harmful to the network controllability than the edge-based ones, and so are the recalculated strategies than their counterparts. The Barabási-Albert scale-free model, which has a highly biased structure, proves to be the most vulnerable of the tested model networks. In contrast, the Erdős-Rényi random model, which lacks structural bias, exhibits much better robustness to both node-based and edge-based attacks. We also survey the control robustness of 25 real-world networks, and the numerical results show that most real networks are control robust to random node failures, which has not been observed in the model networks. And the recalculated betweenness-based strategy is the most efficient way to harm the controllability of real-world networks. Besides, we find that the edge degree is not a good quantity to measure the importance of an edge in terms of network controllability. PMID:27588941

Attack Vulnerability of Network Controllability.

PubMed

Lu, Zhe-Ming; Li, Xin-Feng

2016-01-01

Controllability of complex networks has attracted much attention, and understanding the robustness of network controllability against potential attacks and failures is of practical significance. In this paper, we systematically investigate the attack vulnerability of network controllability for the canonical model networks as well as the real-world networks subject to attacks on nodes and edges. The attack strategies are selected based on degree and betweenness centralities calculated for either the initial network or the current network during the removal, among which random failure is as a comparison. It is found that the node-based strategies are often more harmful to the network controllability than the edge-based ones, and so are the recalculated strategies than their counterparts. The Barabási-Albert scale-free model, which has a highly biased structure, proves to be the most vulnerable of the tested model networks. In contrast, the Erdős-Rényi random model, which lacks structural bias, exhibits much better robustness to both node-based and edge-based attacks. We also survey the control robustness of 25 real-world networks, and the numerical results show that most real networks are control robust to random node failures, which has not been observed in the model networks. And the recalculated betweenness-based strategy is the most efficient way to harm the controllability of real-world networks. Besides, we find that the edge degree is not a good quantity to measure the importance of an edge in terms of network controllability.

A benchmark system to optimize our defense against an attack on the US food supply using the Risk Reduction Effectiveness and Capabilities Assessment Program.

PubMed

Hodoh, Ofia; Dallas, Cham E; Williams, Paul; Jaine, Andrew M; Harris, Curt

2015-01-01

A predictive system was developed and tested in a series of exercises with the objective of evaluating the preparedness and effectiveness of the multiagency response to food terrorism attacks. A computerized simulation model, Risk Reduction Effectiveness and Capabilities Assessment Program (RRECAP), was developed to identify the key factors that influence the outcomes of an attack and quantify the relative reduction of such outcomes caused by each factor. The model was evaluated in a set of Tabletop and Full-Scale Exercises that simulate biological and chemical attacks on the food system. More than 300 participants representing more than 60 federal, state, local, and private sector agencies and organizations. The exercises showed that agencies could use RRECAP to identify and prioritize their advance preparation to mitigate such attacks with minimal expense. RRECAP also demonstrated the relative utility and limitations of the ability of medical resources to treat patients if responders do not recognize and mitigate the attack rapidly, and the exercise results showed that proper advance preparation would reduce these deficiencies. Using computer simulation prediction of the medical outcomes of food supply attacks to identify optimal remediation activities and quantify the benefits of various measures provides a significant tool to agencies in both the public and private sector as they seek to prepare for such an attack.

Modeling and analyzing cascading dynamics of the Internet based on local congestion information

NASA Astrophysics Data System (ADS)

Zhu, Qian; Nie, Jianlong; Zhu, Zhiliang; Yu, Hai; Xue, Yang

2018-06-01

Cascading failure has already become one of the vital issues in network science. By considering realistic network operational settings, we propose the congestion function to represent the congested extent of node and construct a local congestion-aware routing strategy with a tunable parameter. We investigate the cascading failures on the Internet triggered by deliberate attacks. Simulation results show that the tunable parameter has an optimal value that makes the network achieve a maximum level of robustness. The robustness of the network has a positive correlation with tolerance parameter, but it has a negative correlation with the packets generation rate. In addition, there exists a threshold of the attacking proportion of nodes that makes the network achieve the lowest robustness. Moreover, by introducing the concept of time delay for information transmission on the Internet, we found that an increase of the time delay will decrease the robustness of the network rapidly. The findings of the paper will be useful for enhancing the robustness of the Internet in the future.

Modelling the host-pathogen interactions of macrophages and Candida albicans using Game Theory and dynamic optimization.

PubMed

Dühring, Sybille; Ewald, Jan; Germerodt, Sebastian; Kaleta, Christoph; Dandekar, Thomas; Schuster, Stefan

2017-07-01

The release of fungal cells following macrophage phagocytosis, called non-lytic expulsion, is reported for several fungal pathogens. On one hand, non-lytic expulsion may benefit the fungus in escaping the microbicidal environment of the phagosome. On the other hand, the macrophage could profit in terms of avoiding its own lysis and being able to undergo proliferation. To analyse the causes of non-lytic expulsion and the relevance of macrophage proliferation in the macrophage- Candida albicans interaction, we employ Evolutionary Game Theory and dynamic optimization in a sequential manner. We establish a game-theoretical model describing the different strategies of the two players after phagocytosis. Depending on the parameter values, we find four different Nash equilibria and determine the influence of the systems state of the host upon the game. As our Nash equilibria are a direct consequence of the model parameterization, we can depict several biological scenarios. A parameter region, where the host response is robust against the fungal infection, is determined. We further apply dynamic optimization to analyse whether macrophage mitosis is relevant in the host-pathogen interaction of macrophages and C. albicans For this, we study the population dynamics of the macrophage- C. albicans interactions and the corresponding optimal controls for the macrophages, indicating the best macrophage strategy of switching from proliferation to attacking fungal cells. © 2017 The Author(s).

Assessing predation risk: optimal behaviour and rules of thumb.

PubMed

Welton, Nicky J; McNamara, John M; Houston, Alasdair I

2003-12-01

We look at a simple model in which an animal makes behavioural decisions over time in an environment in which all parameters are known to the animal except predation risk. In the model there is a trade-off between gaining information about predation risk and anti-predator behaviour. All predator attacks lead to death for the prey, so that the prey learns about predation risk by virtue of the fact that it is still alive. We show that it is not usually optimal to behave as if the current unbiased estimate of the predation risk is its true value. We consider two different ways to model reproduction; in the first scenario the animal reproduces throughout its life until it dies, and in the second scenario expected reproductive success depends on the level of energy reserves the animal has gained by some point in time. For both of these scenarios we find results on the form of the optimal strategy and give numerical examples which compare optimal behaviour with behaviour under simple rules of thumb. The numerical examples suggest that the value of the optimal strategy over the rules of thumb is greatest when there is little current information about predation risk, learning is not too costly in terms of predation, and it is energetically advantageous to learn about predation. We find that for the model and parameters investigated, a very simple rule of thumb such as 'use the best constant control' performs well.

The anatomy of a shark attack: a case report and review of the literature.

PubMed

Caldicott, D G; Mahajani, R; Kuhn, M

2001-07-01

Shark attacks are rare but are associated with a high morbidity and significant mortality. We report the case of a patient's survival from a shark attack and their subsequent emergency medical and surgical management. Using data from the International Shark Attack File, we review the worldwide distribution and incidence of shark attack. A review of the world literature examines the features which make shark attacks unique pathological processes. We offer suggestions for strategies of management of shark attack, and techniques for avoiding adverse outcomes in human encounters with these endangered creatures.

Comment on “Cryptanalysis and improvement of multiparty semiquantum secret sharing based on rearranging orders of qubits”

NASA Astrophysics Data System (ADS)

Gao, Gan

2017-11-01

In this paper, we show that the attack strategy [A. Yin and F. Fu, Mod. Phys. Lett. B 30 (2016) 1650415] fails, that is, the last agent and other agents cannot get the sender’s secret keys without being detected by using the attack strategy.

Forgiveness, coping, and terrorism: do tendency to forgive and coping strategies associate with the level of posttraumatic symptoms of injured victims of terror attacks?

PubMed

Weinberg, Michael; Gil, Sharon; Gilbar, Ora

2014-07-01

The study examined the tendency to forgive (self, others, and situations) and coping strategies (problem-focused, emotion-focused, and avoidance) among terror attack victims as associated with posttraumatic stress disorder (PTSD) symptom severity. The sample included 108 terror victims who had been injured in terror attacks (mean age 46.23, standard deviation = 11.61; 58.3% male). Participants agreed to undergo assessments of their PTSD symptoms, coping strategies, and tendency to forgive. A nested structural equation model design showed that tendency to forgive is positively associated with problem-focused coping and negatively associated with avoidance coping. Additionally, tendency to forgive and problem-focused coping are associated with decreased PTSD symptom severity, whereas emotion-focused coping is associated with elevated PTSD symptom severity. Tendency to forgive and coping strategies are significantly associated with each other and with severity of PTSD symptoms among individuals injured in terror attacks. Theoretical and clinical implications of the findings are discussed. © 2013 Wiley Periodicals, Inc.

Metrics for Assessment of Smart Grid Data Integrity Attacks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Annarita Giani; Miles McQueen; Russell Bent

2012-07-01

There is an emerging consensus that the nation’s electricity grid is vulnerable to cyber attacks. This vulnerability arises from the increasing reliance on using remote measurements, transmitting them over legacy data networks to system operators who make critical decisions based on available data. Data integrity attacks are a class of cyber attacks that involve a compromise of information that is processed by the grid operator. This information can include meter readings of injected power at remote generators, power flows on transmission lines, and relay states. These data integrity attacks have consequences only when the system operator responds to compromised datamore » by redispatching generation under normal or contingency protocols. These consequences include (a) financial losses from sub-optimal economic dispatch to service loads, (b) robustness/resiliency losses from placing the grid at operating points that are at greater risk from contingencies, and (c) systemic losses resulting from cascading failures induced by poor operational choices. This paper is focused on understanding the connections between grid operational procedures and cyber attacks. We first offer two examples to illustrate how data integrity attacks can cause economic and physical damage by misleading operators into taking inappropriate decisions. We then focus on unobservable data integrity attacks involving power meter data. These are coordinated attacks where the compromised data are consistent with the physics of power flow, and are therefore passed by any bad data detection algorithm. We develop metrics to assess the economic impact of these attacks under re-dispatch decisions using optimal power flow methods. These metrics can be use to prioritize the adoption of appropriate countermeasures including PMU placement, encryption, hardware upgrades, and advance attack detection algorithms.« less

Finding optimal vaccination strategies for pandemic influenza using genetic algorithms.

PubMed

Patel, Rajan; Longini, Ira M; Halloran, M Elizabeth

2005-05-21

In the event of pandemic influenza, only limited supplies of vaccine may be available. We use stochastic epidemic simulations, genetic algorithms (GA), and random mutation hill climbing (RMHC) to find optimal vaccine distributions to minimize the number of illnesses or deaths in the population, given limited quantities of vaccine. Due to the non-linearity, complexity and stochasticity of the epidemic process, it is not possible to solve for optimal vaccine distributions mathematically. However, we use GA and RMHC to find near optimal vaccine distributions. We model an influenza pandemic that has age-specific illness attack rates similar to the Asian pandemic in 1957-1958 caused by influenza A(H2N2), as well as a distribution similar to the Hong Kong pandemic in 1968-1969 caused by influenza A(H3N2). We find the optimal vaccine distributions given that the number of doses is limited over the range of 10-90% of the population. While GA and RMHC work well in finding optimal vaccine distributions, GA is significantly more efficient than RMHC. We show that the optimal vaccine distribution found by GA and RMHC is up to 84% more effective than random mass vaccination in the mid range of vaccine availability. GA is generalizable to the optimization of stochastic model parameters for other infectious diseases and population structures.

Mobbing: a problem in flocking and deterrence

NASA Astrophysics Data System (ADS)

Elias Tousley, M.; Glaze, Owen; Schall, Anna; Amador Kane, Suzanne

2010-03-01

We present experimental and theoretical studies of one type of mobbing behavior in which swarms of prey animals (e.g., tree swallows) harass a predator (e.g., a red-tailed hawk). Empirical field data were collected for tree swallows mobbing a fixed model predator; previous studies have established that this experimental design provokes the same response as actual ``perch-and-wait'' predator behavior. We extended these earlier studies using stereometric video to record the three-dimensional trajectories of prey birds and mobbing cries; we also analyzed single-angle video data taken of crows mobbing red-tailed hawks in flight. Video recordings of red-tailed hawk flight were filmed and analyzed to establish the dynamics of potential predator attacks. The trajectory analysis employed particle-tracking methods and statistical analyses to understand and model the dynamical rules governing this behavior. Swarming behavior during mobbing exhibited a high degree of periodicity and coordination both for fixed predator and in-flight mobbing attacks. The trajectories of individual mobbing birds were analyzed as a random walk superimposed on an approximately elliptical flightpath. Computer simulation studies reproduce several aspects of this behavior, in particular explaining how the mobbing strategy employed by prey birds minimizes the risk of hawk predation while optimizing the frequency of harassing attacks.

Adaptive optimisation-offline cyber attack on remote state estimator

NASA Astrophysics Data System (ADS)

Huang, Xin; Dong, Jiuxiang

2017-10-01

Security issues of cyber-physical systems have received increasing attentions in recent years. In this paper, deception attacks on the remote state estimator equipped with the chi-squared failure detector are considered, and it is assumed that the attacker can monitor and modify all the sensor data. A novel adaptive optimisation-offline cyber attack strategy is proposed, where using the current and previous sensor data, the attack can yield the largest estimation error covariance while ensuring to be undetected by the chi-squared monitor. From the attacker's perspective, the attack is better than the existing linear deception attacks to degrade the system performance. Finally, some numerical examples are provided to demonstrate theoretical results.

Cyber situation awareness: modeling detection of cyber attacks with instance-based learning theory.

PubMed

Dutt, Varun; Ahn, Young-Suk; Gonzalez, Cleotilde

2013-06-01

To determine the effects of an adversary's behavior on the defender's accurate and timely detection of network threats. Cyber attacks cause major work disruption. It is important to understand how a defender's behavior (experience and tolerance to threats), as well as adversarial behavior (attack strategy), might impact the detection of threats. In this article, we use cognitive modeling to make predictions regarding these factors. Different model types representing a defender, based on Instance-Based Learning Theory (IBLT), faced different adversarial behaviors. A defender's model was defined by experience of threats: threat-prone (90% threats and 10% nonthreats) and nonthreat-prone (10% threats and 90% nonthreats); and different tolerance levels to threats: risk-averse (model declares a cyber attack after perceiving one threat out of eight total) and risk-seeking (model declares a cyber attack after perceiving seven threats out of eight total). Adversarial behavior is simulated by considering different attack strategies: patient (threats occur late) and impatient (threats occur early). For an impatient strategy, risk-averse models with threat-prone experiences show improved detection compared with risk-seeking models with nonthreat-prone experiences; however, the same is not true for a patient strategy. Based upon model predictions, a defender's prior threat experiences and his or her tolerance to threats are likely to predict detection accuracy; but considering the nature of adversarial behavior is also important. Decision-support tools that consider the role of a defender's experience and tolerance to threats along with the nature of adversarial behavior are likely to improve a defender's overall threat detection.

Tabu Search enhances network robustness under targeted attacks

NASA Astrophysics Data System (ADS)

Sun, Shi-wen; Ma, Yi-lin; Li, Rui-qi; Wang, Li; Xia, Cheng-yi

2016-03-01

We focus on the optimization of network robustness with respect to intentional attacks on high-degree nodes. Given an existing network, this problem can be considered as a typical single-objective combinatorial optimization problem. Based on the heuristic Tabu Search optimization algorithm, a link-rewiring method is applied to reconstruct the network while keeping the degree of every node unchanged. Through numerical simulations, BA scale-free network and two real-world networks are investigated to verify the effectiveness of the proposed optimization method. Meanwhile, we analyze how the optimization affects other topological properties of the networks, including natural connectivity, clustering coefficient and degree-degree correlation. The current results can help to improve the robustness of existing complex real-world systems, as well as to provide some insights into the design of robust networks.

Investigating the Aftermath of Terror: Fundamental Outcomes, Methodological Choices, and Future Directions.

PubMed

Gradus, Jaimie L; Marx, Brian P; Sloan, Denise M

2016-06-01

Acts of terrorism are becoming increasingly common throughout the world. These events represent a significant public health concern given the associated health consequences. Although it is clear that terrorist attacks have mental and physical health sequelae, the exact nature and prevalence of these consequences are unclear. Epidemiological research can play an important role in better understanding the mental and physical impact of terrorist attacks. In this editorial, we highlight recent epidemiological research on these terrorism-related health outcomes. We also provide suggestions for how future studies can build on the existing literature and describe ways in which epidemiological methods can be harnessed to extend the current literature. Lastly, we offer recommendations on how to best prepare communities for the aftermath of terrorist attacks, highlighting secondary intervention and prevention strategies. Overall, multilevel strategies are needed to adequately cope with the growing rise of terrorist acts, and these strategies will have to be reassessed as the nature of terrorist attacks changes.

Advanced launch system trajectory optimization using suboptimal control

NASA Technical Reports Server (NTRS)

Shaver, Douglas A.; Hull, David G.

1993-01-01

The maximum-final mass trajectory of a proposed configuration of the Advanced Launch System is presented. A model for the two-stage rocket is given; the optimal control problem is formulated as a parameter optimization problem; and the optimal trajectory is computed using a nonlinear programming code called VF02AD. Numerical results are presented for the controls (angle of attack and velocity roll angle) and the states. After the initial rotation, the angle of attack goes to a positive value to keep the trajectory as high as possible, returns to near zero to pass through the transonic regime and satisfy the dynamic pressure constraint, returns to a positive value to keep the trajectory high and to take advantage of minimum drag at positive angle of attack due to aerodynamic shading of the booster, and then rolls off to negative values to satisfy the constraints. Because the engines cannot be throttled, the maximum dynamic pressure occurs at a single point; there is no maximum dynamic pressure subarc. To test approximations for obtaining analytical solutions for guidance, two additional optimal trajectories are computed: one using untrimmed aerodynamics and one using no atmospheric effects except for the dynamic pressure constraint. It is concluded that untrimmed aerodynamics has a negligible effect on the optimal trajectory and that approximate optimal controls should be able to be obtained by treating atmospheric effects as perturbations.

Negative Campaigning and the Logic of Retaliation in Multiparty Competition.

PubMed

Dolezal, Martin; Ennser-Jedenastik, Laurenz; Müller, Wolfgang C

2016-04-01

The extant literature has demonstrated that the logic of retaliation is a core feature of negative campaigning. Attacks by one side induce counterattacks by the other. Yet most research on the interactive nature of negative campaigning is limited to two-party competition and provides little theoretical justification for why political actors should respond to attacks with counterattacks. The present paper addresses these research gaps. We argue that the negativity bias in human information processing and the zero-sum nature of elections make retaliation a rational strategy. Importantly, these arguments also imply that retaliation may not be the only plausible response to attacks in multiparty systems. Rather, parties may prefer to react to attacks from one competitor by attacking another. To grasp empirically how being attacked and attacking are related, we conduct a highly disaggregated time series analysis of such instances while controlling for other factors that may influence actor behavior. Our analyses draw on several thousand party press releases issued during three national election campaigns in Austria, a typical European multiparty system. They show that retaliation is an important strategy also in multiparty politics. Yet in such context, parties do not exclusively follow a tit-for-tat approach but rather display more complex patterns of attack behavior.

Negative Campaigning and the Logic of Retaliation in Multiparty Competition

PubMed Central

Dolezal, Martin; Ennser-Jedenastik, Laurenz; Müller, Wolfgang C.

2016-01-01

The extant literature has demonstrated that the logic of retaliation is a core feature of negative campaigning. Attacks by one side induce counterattacks by the other. Yet most research on the interactive nature of negative campaigning is limited to two-party competition and provides little theoretical justification for why political actors should respond to attacks with counterattacks. The present paper addresses these research gaps. We argue that the negativity bias in human information processing and the zero-sum nature of elections make retaliation a rational strategy. Importantly, these arguments also imply that retaliation may not be the only plausible response to attacks in multiparty systems. Rather, parties may prefer to react to attacks from one competitor by attacking another. To grasp empirically how being attacked and attacking are related, we conduct a highly disaggregated time series analysis of such instances while controlling for other factors that may influence actor behavior. Our analyses draw on several thousand party press releases issued during three national election campaigns in Austria, a typical European multiparty system. They show that retaliation is an important strategy also in multiparty politics. Yet in such context, parties do not exclusively follow a tit-for-tat approach but rather display more complex patterns of attack behavior. PMID:27904657

Evaluation of Gritting Strategies for High Angle of Attack Using Wind Tunnel and Flight Test Data for the F/A-18

NASA Technical Reports Server (NTRS)

Hall, Robert M.; Erickson, Gary E.; Fox, Charles H., Jr.; Banks, Daniel W.; Fisher, David F.

1998-01-01

A subsonic study of high-angle-of-attack gritting strategies was undertaken with a 0.06-scale model of the F/A-18, which was assumed to be typical of airplanes with smooth-sided forebodies. This study was conducted in the Langley 7- by 10-Foot High-Speed Tunnel and was intended to more accurately simulate flight boundary layer characteristics on the model in the wind tunnel than would be possible by using classical, low-angle-of-attack gritting on the fuselage. Six-component force and moment data were taken with an internally mounted strain-gauge balance, while pressure data were acquired by using electronically scanned pressure transducers. Data were taken at zero sideslip over an angle-of-attack range from 0 deg to 40 deg and, at selected angles of attack, over sideslip angles from -10 deg to 10 deg. Free-stream Mach number was fixed at 0.30, which resulted in a Reynolds number, based on mean aerodynamic chord, of 1.4 x 10(exp 6). Pressure data measured over the forebody and leading-edge extensions are compared to similar pressure data taken by a related NASA flight research program by using a specially instrumented F/A-18, the High-Alpha Research Vehicle (HARV). Preliminary guidelines for high-angle-of-attack gritting strategies are given.

Localization-Free Detection of Replica Node Attacks in Wireless Sensor Networks Using Similarity Estimation with Group Deployment Knowledge

PubMed Central

Ding, Chao; Yang, Lijun; Wu, Meng

2017-01-01

Due to the unattended nature and poor security guarantee of the wireless sensor networks (WSNs), adversaries can easily make replicas of compromised nodes, and place them throughout the network to launch various types of attacks. Such an attack is dangerous because it enables the adversaries to control large numbers of nodes and extend the damage of attacks to most of the network with quite limited cost. To stop the node replica attack, we propose a location similarity-based detection scheme using deployment knowledge. Compared with prior solutions, our scheme provides extra functionalities that prevent replicas from generating false location claims without deploying resource-consuming localization techniques on the resource-constraint sensor nodes. We evaluate the security performance of our proposal under different attack strategies through heuristic analysis, and show that our scheme achieves secure and robust replica detection by increasing the cost of node replication. Additionally, we evaluate the impact of network environment on the proposed scheme through theoretic analysis and simulation experiments, and indicate that our scheme achieves effectiveness and efficiency with substantially lower communication, computational, and storage overhead than prior works under different situations and attack strategies. PMID:28098846

Localization-Free Detection of Replica Node Attacks in Wireless Sensor Networks Using Similarity Estimation with Group Deployment Knowledge.

PubMed

Ding, Chao; Yang, Lijun; Wu, Meng

2017-01-15

Due to the unattended nature and poor security guarantee of the wireless sensor networks (WSNs), adversaries can easily make replicas of compromised nodes, and place them throughout the network to launch various types of attacks. Such an attack is dangerous because it enables the adversaries to control large numbers of nodes and extend the damage of attacks to most of the network with quite limited cost. To stop the node replica attack, we propose a location similarity-based detection scheme using deployment knowledge. Compared with prior solutions, our scheme provides extra functionalities that prevent replicas from generating false location claims without deploying resource-consuming localization techniques on the resource-constraint sensor nodes. We evaluate the security performance of our proposal under different attack strategies through heuristic analysis, and show that our scheme achieves secure and robust replica detection by increasing the cost of node replication. Additionally, we evaluate the impact of network environment on the proposed scheme through theoretic analysis and simulation experiments, and indicate that our scheme achieves effectiveness and efficiency with substantially lower communication, computational, and storage overhead than prior works under different situations and attack strategies.

Robustness of non-interdependent and interdependent networks against dependent and adaptive attacks

NASA Astrophysics Data System (ADS)

Tyra, Adam; Li, Jingtao; Shang, Yilun; Jiang, Shuo; Zhao, Yanjun; Xu, Shouhuai

2017-09-01

Robustness of complex networks has been extensively studied via the notion of site percolation, which typically models independent and non-adaptive attacks (or disruptions). However, real-life attacks are often dependent and/or adaptive. This motivates us to characterize the robustness of complex networks, including non-interdependent and interdependent ones, against dependent and adaptive attacks. For this purpose, dependent attacks are accommodated by L-hop percolation where the nodes within some L-hop (L ≥ 0) distance of a chosen node are all deleted during one attack (with L = 0 degenerating to site percolation). Whereas, adaptive attacks are launched by attackers who can make node-selection decisions based on the network state in the beginning of each attack. The resulting characterization enriches the body of knowledge with new insights, such as: (i) the Achilles' Heel phenomenon is only valid for independent attacks, but not for dependent attacks; (ii) powerful attack strategies (e.g., targeted attacks and dependent attacks, dependent attacks and adaptive attacks) are not compatible and cannot help the attacker when used collectively. Our results shed some light on the design of robust complex networks.

A Probabilistic Risk Mitigation Model for Cyber-Attacks to PMU Networks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mousavian, Seyedamirabbas; Valenzuela, Jorge; Wang, Jianhui

The power grid is becoming more dependent on information and communication technologies. Complex networks of advanced sensors such as phasor measurement units (PMUs) are used to collect real time data to improve the observability of the power system. Recent studies have shown that the power grid has significant cyber vulnerabilities which could increase when PMUs are used extensively. Therefore, recognizing and responding to vulnerabilities are critical to the security of the power grid. This paper proposes a risk mitigation model for optimal response to cyber-attacks to PMU networks. We model the optimal response action as a mixed integer linear programmingmore » (MILP) problem to prevent propagation of the cyber-attacks and maintain the observability of the power system.« less

F-18 High Alpha Research Vehicle (HARV) parameter identification flight test maneuvers for optimal input design validation and lateral control effectiveness

NASA Technical Reports Server (NTRS)

Morelli, Eugene A.

1995-01-01

Flight test maneuvers are specified for the F-18 High Alpha Research Vehicle (HARV). The maneuvers were designed for open loop parameter identification purposes, specifically for optimal input design validation at 5 degrees angle of attack, identification of individual strake effectiveness at 40 and 50 degrees angle of attack, and study of lateral dynamics and lateral control effectiveness at 40 and 50 degrees angle of attack. Each maneuver is to be realized by applying square wave inputs to specific control effectors using the On-Board Excitation System (OBES). Maneuver descriptions and complete specifications of the time/amplitude points define each input are included, along with plots of the input time histories.

Advanced Email Risk Classification and Recipient Decision Assistance

ERIC Educational Resources Information Center

Estes, Aaron

2016-01-01

Email attacks comprise an overwhelming majority of the daily attacks on modern enterprise. "Phishing" is the leading attack vector for the world's most dangerous threats such as the so-called, Advanced Persistent Threat (APT), and hacktivist groups such as Anonymous and LulzSec. The leading mitigation strategy is a combination of user…

Network Security Risk Assessment System Based on Attack Graph and Markov Chain

NASA Astrophysics Data System (ADS)

Sun, Fuxiong; Pi, Juntao; Lv, Jin; Cao, Tian

2017-10-01

Network security risk assessment technology can be found in advance of the network problems and related vulnerabilities, it has become an important means to solve the problem of network security. Based on attack graph and Markov chain, this paper provides a Network Security Risk Assessment Model (NSRAM). Based on the network infiltration tests, NSRAM generates the attack graph by the breadth traversal algorithm. Combines with the international standard CVSS, the attack probability of atomic nodes are counted, and then the attack transition probabilities of ones are calculated by Markov chain. NSRAM selects the optimal attack path after comprehensive measurement to assessment network security risk. The simulation results show that NSRAM can reflect the actual situation of network security objectively.

Cyber Security Audit and Attack Detection Toolkit

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peterson, Dale

2012-05-31

This goal of this project was to develop cyber security audit and attack detection tools for industrial control systems (ICS). Digital Bond developed and released a tool named Bandolier that audits ICS components commonly used in the energy sector against an optimal security configuration. The Portaledge Project developed a capability for the PI Historian, the most widely used Historian in the energy sector, to aggregate security events and detect cyber attacks.

Optimal Predator Risk Assessment by the Sonar-Jamming Arctiine Moth Bertholdia trigona

PubMed Central

Corcoran, Aaron J.; Wagner, Ryan D.; Conner, William E.

2013-01-01

Nearly all animals face a tradeoff between seeking food and mates and avoiding predation. Optimal escape theory holds that an animal confronted with a predator should only flee when benefits of flight (increased survival) outweigh the costs (energetic costs, lost foraging time, etc.). We propose a model for prey risk assessment based on the predator's stage of attack. Risk level should increase rapidly from when the predator detects the prey to when it commits to the attack. We tested this hypothesis using a predator – the echolocating bat – whose active biosonar reveals its stage of attack. We used a prey defense – clicking used for sonar jamming by the tiger moth Bertholdia trigona– that can be readily studied in the field and laboratory and is enacted simultaneously with evasive flight. We predicted that prey employ defenses soon after being detected and targeted, and that prey defensive thresholds discriminate between legitimate predatory threats and false threats where a nearby prey is attacked. Laboratory and field experiments using playbacks of ultrasound signals and naturally behaving bats, respectively, confirmed our predictions. Moths clicked soon after bats detected and targeted them. Also, B. trigona clicking thresholds closely matched predicted optimal thresholds for discriminating legitimate and false predator threats for bats using search and approach phase echolocation – the period when bats are searching for and assessing prey. To our knowledge, this is the first quantitative study to correlate the sensory stimuli that trigger defensive behaviors with measurements of signals provided by predators during natural attacks in the field. We propose theoretical models for explaining prey risk assessment depending on the availability of cues that reveal a predator's stage of attack. PMID:23671686

DOE Office of Scientific and Technical Information (OSTI.GOV)

Canavan, G.H.

Attack allocation optimizations produce stability indices for unsymmetrical forces that indicate significant regions of both stability and instability and that have their minimum values roughly when the two sides have equal forces. This note derives combined stability indices for unsymmetrical offensive force configurations. The indices are based on optimal allocations of offensive missiles between vulnerable missiles and value based on the minimization of first strike cost, which is done analytically. Exchanges are modeled probabalistically and their results are converted into first and second strike costs through approximations to the damage to the value target sets held at risk. The stabilitymore » index is the product of the ratio of first to second strike costs seen by the two sides. Optimal allocations scale directly on the opponent`s vulnerable missiles, inversely on one`s own total weapons, and only logarithmically on the attacker`s damage preference, kill probability, and relative target set. The defender`s allocation scales in a similar manner on the attacker`s parameters. First and second strike magnitudes increase roughly linearly for the side with greater forces and decrease linearly for the side with fewer. Conversely, the first and second strike magnitudes decrease for the side with greater forces and increase for the side with fewer. These trends are derived and discussed analytically. The resulting stability indices exhibit a minimum where the two sides have roughly equal forces. If one side has much larger forces than the other, his costs drop to levels low enough that he is relatively insensitive to whether he strikes first or second. These calculations are performed with the analytic attack allocation appropriate for moderate forces, so some differences could be expected for the largest of the forces considered.« less

Antiplatelet Regimen for Patients With Breakthrough Strokes While on Aspirin: A Systematic Review and Meta-Analysis.

PubMed

Lee, Meng; Saver, Jeffrey L; Hong, Keun-Sik; Rao, Neal M; Wu, Yi-Ling; Ovbiagele, Bruce

2017-09-01

Optimal antiplatelet therapy after an ischemic stroke or transient ischemic attack while on aspirin is uncertain. We, therefore, conducted a systematic review and meta-analysis. We searched PubMed (1966 to August 2016) and bibliographies of relevant published original studies to identify randomized trials and cohort studies reporting patients who were on aspirin at the time of an index ischemic stroke or transient ischemic attack and reported hazard ratio for major adverse cardiovascular events or recurrent stroke associated with a switch to or addition of another antiplatelet agent versus maintaining aspirin monotherapy. Estimates were combined using a random effects model. Five studies with 8723 patients with ischemic stroke or transient ischemic attack were identified. Clopidogrel was used in 4 cohorts, and ticagrelor was used in 1 cohort. Pooling results showed that addition of or a switch to another antiplatelet agent, versus aspirin monotherapy, was associated with reduced risks of major adverse cardiovascular events (hazard ratio, 0.68; 95% confidence interval, 0.54-0.85) and recurrent stroke (hazard ratio, 0.70; 95% confidence interval, 0.54-0.92). Each of the strategies of addition of and switching another antiplatelet agent showed benefit versus continued aspirin monotherapy, and studies with regimen initiation in the first days after index event showed more homogenous evidence of benefit. Among patients who experience an ischemic stroke or transient ischemic attack while on aspirin monotherapy, the addition of or a switch to another antiplatelet agent, especially in the first days after index event, is associated with fewer future vascular events, including stroke. © 2017 American Heart Association, Inc.

Split-second escape decisions in blue tits (Parus caeruleus)

NASA Astrophysics Data System (ADS)

Lind, Johan; Kaby, Ulrika; Jakobsson, Sven

2002-07-01

Bird mortality is heavily affected by birds of prey. Under attack, take-off is crucial for survival and even minor mistakes in initial escape response can have devastating consequences. Birds may respond differently depending on the character of the predator's attack and these split-second decisions were studied using a model merlin (Falco columbarius) that attacked feeding blue tits (Parus caeruleus) from two different attack angles in two different speeds. When attacked from a low attack angle they took off more steeply than when attacked from a high angle. This is the first study to show that escape behaviour also depends on predator attack speed. The blue tits responded to a high-speed attack by dodging sideways more often than when attacked at a low speed. Escape speed was not significantly affected by the different treatments. Although they have only a split-second before escaping an attack, blue tits do adjust their escape strategy to the prevailing attack conditions.

Public health foundations and the tobacco industry: lessons from Minnesota

PubMed Central

Ibrahim, J; Tsoukalas, T; Glantz, S

2004-01-01

Objective: To investigate whether private foundations can be created in a way that will insulate them from attacks by the tobacco industry, using the Minnesota Partnership for Action Against Tobacco (MPAAT) as a case study. Design: Information was collected from internal tobacco industry documents, court documents, newspapers, and interviews with health advocates and elected officials. Results: The creation of MPAAT as an independent foundation did not insulate it from attacks by tobacco industry allies. During 2001–2002, MPAAT was repeatedly attacked by Attorney General Mike Hatch and major media, using standard tobacco industry rhetoric. This strategy of attack and demands for information were reminiscent of previous attacks on Minnesota's Plan for Nonsmoking and Health and the American Stop Smoking Intervention Study (ASSIST). MPAAT was ultimately forced to restructure its programme to abandon effective community norm change interventions around smoke-free policies and replace them with less effective individual cessation interventions. Neither MPAAT nor other health advocates mounted an effective public response to these attacks, instead relying on the insider strategy of responding in court. Conclusion: It is not possible to avoid attacks by the tobacco industry or its political allies. Like programmes administered by government agencies, tobacco control foundations must be prepared for these attacks, including a proactive plan to educate the public about the principles of community based tobacco control. Public health advocates also need to be willing to take prompt action to defend these programmes and hold public officials who attack tobacco control programmes accountable for their actions. PMID:15333877

Omics Approaches for the Engineering of Pathogen Resistant Plants.

PubMed

Gomez-Casati, Diego F; Pagani, María A; Busi, María V; Bhadauria, Vijai

2016-01-01

The attack of different pathogens, such as bacteria, fungi and viruses has a negative impact on crop production. In counter such attacks, plants have developed different strategies involving the modification of gene expression, activation of several metabolic pathways and post-translational modification of proteins, which culminate into the accumulation of primary and secondary metabolites implicated in plant defense responses. The recent advancement in omics techniques allows the increase coverage of plants transcriptomes, proteomes and metabolomes during pathogen attack, and the modulation of the response after the infection. Omics techniques also allow us to learn more about the biological cycle of the pathogens in addition to the identification of novel virulence factors in pathogens and their host targets. Both approaches become important to decipher the mechanism underlying pathogen attacks and to develop strategies for improving disease-resistant plants. In this review, we summarize some of the contribution of genomics, transcriptomics, proteomics, metabolomics and metallomics in devising the strategies to obtain plants with increased resistance to pathogens. These approaches constitute important research tools in the development of new technologies for the protection against diseases and increase plant production.

Optimal plane change during constant altitude hypersonic flight

NASA Technical Reports Server (NTRS)

Mease, K. D.; Vinh, N. X.; Kuo, S. H.

1988-01-01

Future spacecraft operating in the vicinity of the earth may have resort to the atmosphere as an aid in effecting orbital change. While a previous treatment of this technique chose constant altitude, speed, and angle-of-attack values in order to maximize the plane change for a fixed amount of propellant consumption during hypersonic flight, the former two parameters are presently released from the constraint of constancy. The general characteristics of the optimal controls are described on the basis of the domain of maneuverability, and numerical solutions are obtained for several specific cases. Under the condition of constant-altitude flight, it is generally not optimal to fly at constant angle-of-attack.

Strategic Implications of Hybrid War: A Theory of Victory

DTIC Science & Technology

2009-05-21

Guiding Rules (London: Kegan Paul, Trench, Trubner and Co, Ltd, 1908), 19. A recommended modification to account for current context would be to substitute...of Amateur Strategy: As Exemplified by the Attack on the Dardanelles Fortress in 1915 (New York: Longmans, Green , and Co. Ltd., 1926...Sir Gerald. The Perils of Amateur Strategy: As Exemplified by the Attack on the Dardanelles Fortress in 1915. New York: Longmans, Green , and Co

Strategic Delusions - The Cold Start Doctrine: Proactive Strategy

DTIC Science & Technology

2016-05-26

recent tactical strike in Myanmar is miscued as a precursor for times to come in the regional context.10 These tactical actions also known as Hot...Attacks Militant Camps in Myanmar , Wall Street Journal, June 10, 2015, accessed August 24, 2015, http://www.wsj.com/articles/indian-army-attacks...militant-camps-in- myanmar -1433927858. 7 imperatives associated with the Indian PAS and its validation through the framework of strategy and the

Relative risk perception for terrorism: implications for preparedness and risk communication.

PubMed

Caponecchia, Carlo

2012-09-01

Terrorism presents a significant risk that is often approached at public policy, infrastructure, or emergency management level. Public perceptions of the likelihood of terrorist events, and how this may relate to individual preparedness, are not always extensively examined. The tendency to think that negative events are less likely to happen to oneself than to the average person is known as optimism bias. Optimism bias is relevant to perceptions of terrorism, because it is thought to be related to a reduction in precaution use. Using an online survey of 164 participants, this study aimed to determine whether Sydney residents thought they had a lower likelihood of experiencing terrorist events than other Australians. Significant optimism bias was observed for witnessing terrorist events, but not for personally experiencing terrorist events. In addition, Sydney residents tended to think that terrorist attacks were more likely to occur in Sydney than another major Australian city in the next five years. At the same time, household and workplace preparedness for terrorism was quite low, as was awareness of emergency strategies in the central business district. Perceptions of high likelihood of terrorism happening in one's own city, yet low preparedness present a challenge for risk communication and emergency management strategies. The diversity of possible terrorist targets, and the simple plans that can moderate the effects of a disaster may need to be emphasized in future anti-terrorism initiatives. © 2012 Society for Risk Analysis.

Coherent attacking continuous-variable quantum key distribution with entanglement in the middle

NASA Astrophysics Data System (ADS)

Zhang, Zhaoyuan; Shi, Ronghua; Zeng, Guihua; Guo, Ying

2018-06-01

We suggest an approach on the coherent attack of continuous-variable quantum key distribution (CVQKD) with an untrusted entangled source in the middle. The coherent attack strategy can be performed on the double links of quantum system, enabling the eavesdropper to steal more information from the proposed scheme using the entanglement correlation. Numeric simulation results show the improved performance of the attacked CVQKD system in terms of the derived secret key rate with the controllable parameters maximizing the stolen information.

Department of Defense Information Enterprise: Strategic Plan 2010-2012

DTIC Science & Technology

2010-04-01

migrate from circuit-based technology to a converged (voice, video , and data) IP network and UC services environment. Ensure the optimal...Kevin Coleman, “Cyber Attacks on Supply Chain Systems,” Defense Tech, April 15, 2009 8 Lolita C. Baldor, “Federal Web Sites Knocked Out by Cyber Attack

Lethal Trap Trees and Semiochemical Repellents as Area Host Protection Strategies for Spruce Beetle (Coleoptera: Curculionidae, Scolytinae) in Utah.

PubMed

Matthew Hansen, E; Steven Munson, A; Blackford, Darren C; Wakarchuk, David; Scott Baggett, L

2016-10-01

We tested lethal trap trees and repellent semiochemicals as area treatments to protect host trees from spruce beetle (Dendroctonus rufipennis Kirby) attacks. Lethal trap tree treatments ("spray treatment") combined a spruce beetle bait with carbaryl treatment of the baited spruce. Repellent treatments ("spray-repellent") combined a baited lethal trap tree within a 16-m grid of MCH (3-methylcyclohex-2-en-1-one) and two novel spruce beetle repellents. After beetle flight, we surveyed all trees within 50 m of plot center, stratified by 10-m radius subplots, and compared attack rates to those from baited and unbaited control plots. Compared to the baited controls, spruce in the spray treatment had significantly reduced likelihood of a more severe attack classification (e.g., mass-attacked over strip-attacked or unsuccessful-attacked over unattacked). Because spruce in the spray treatment also had significantly heightened probability of more severe attack classification than those in the unbaited controls, however, we do not recommend lethal trap trees as a stand-alone beetle suppression strategy for epidemic beetle populations. Spruce in the spray-repellent treatment were slightly more likely to be classified as more severely attacked within 30 m of plot center compared to unbaited controls but, overall, had reduced probabilities of beetle attack over the entire 50-m radius plots. The semiochemical repellents deployed in this study were effective at reducing attacks on spruce within treated plots despite the presence of a centrally located spruce beetle bait. Further testing will be required to clarify operational protocols such as dose, elution rate, and release device spacing. Published by Oxford University Press on behalf of Entomological Society of America 2016. This work is written by US Government employees and is in the public domain in the US.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoette, Trisha Marie

Throughout history, as new chemical threats arose, strategies for the defense against chemical attacks have also evolved. As a part of an Early Career Laboratory Directed Research and Development project, a systems analysis of past, present, and future chemical terrorism scenarios was performed to understand how the chemical threats and attack strategies change over time. For the analysis, the difficulty in executing chemical attack was evaluated within a framework of three major scenario elements. First, historical examples of chemical terrorism were examined to determine how the use of chemical threats, versus other weapons, contributed to the successful execution of themore » attack. Using the same framework, the future of chemical terrorism was assessed with respect to the impact of globalization and new technologies. Finally, the efficacy of the current defenses against contemporary chemical terrorism was considered briefly. The results of this analysis justify the need for continued diligence in chemical defense.« less

Information spread in networks: Games, optimal control, and stabilization

NASA Astrophysics Data System (ADS)

Khanafer, Ali

This thesis focuses on designing efficient mechanisms for controlling information spread in networks. We consider two models for information spread. The first one is the well-known distributed averaging dynamics. The second model is a nonlinear one that describes virus spread in computer and biological networks. We seek to design optimal, robust, and stabilizing controllers under practical constraints. For distributed averaging networks, we study the interaction between a network designer and an adversary. We consider two types of attacks on the network. In Attack-I, the adversary strategically disconnects a set of links to prevent the nodes from reaching consensus. Meanwhile, the network designer assists the nodes in reaching consensus by changing the weights of a limited number of links in the network. We formulate two problems to describe this competition where the order in which the players act is reversed in the two problems. Although the canonical equations provided by the Pontryagin's Maximum Principle (MP) seem to be intractable, we provide an alternative characterization for the optimal strategies that makes connection to potential theory. Further, we provide a sufficient condition for the existence of a saddle-point equilibrium (SPE) for the underlying zero-sum game. In Attack-II, the designer and the adversary are both capable of altering the measurements of all nodes in the network by injecting global signals. We impose two constraints on both players: a power constraint and an energy constraint. We assume that the available energy to each player is not sufficient to operate at maximum power throughout the horizon of the game. We show the existence of an SPE and derive the optimal strategies in closed form for this attack scenario. As an alternative to the "network designer vs. adversary" framework, we investigate the possibility of stabilizing unknown network diffusion processes using a distributed mechanism, where the uncertainty is due to an attack on the network. To this end, we propose a distributed version of the classical logic-based supervisory control scheme. Given a network of agents whose dynamics contain unknown parameters, the distributed supervisory control scheme is used to assist the agents to converge to a certain set-point without requiring them to have explicit knowledge of that set-point. Unlike the classical supervisory control scheme where a centralized supervisor makes switching decisions among the candidate controllers, in our scheme, each agent is equipped with a local supervisor that switches among the available controllers. The switching decisions made at a certain agent depend only on the information from its neighboring agents. We provide sufficient conditions for stabilization and apply our framework to the distributed averaging problem in the presence of large modeling uncertainty. For infected networks, we study the stability properties of a susceptible-infected-susceptible (SIS) diffusion model, so-called the n-intertwined Markov model, over arbitrary network topologies. Similar to the majority of infection spread dynamics, this model exhibits a threshold phenomenon. When the curing rates in the network are high, the all-healthy state is the unique equilibrium over the network. Otherwise, an endemic equilibrium state emerges, where some infection remains within the network. Using notions from positive systems theory, we provide conditions for the global asymptotic stability of the equilibrium points in both cases over strongly and weakly connected directed networks based on the value of the basic reproduction number, a fundamental quantity in the study of epidemics. Furthermore, we demonstrate that the n-intertwined Markov model can be viewed as a best-response dynamical system of a concave game among the nodes. This characterization allows us to cast new infection spread dynamics; additionally, we provide a sufficient condition, for the global convergence to the all-healthy state, that can be checked in a distributed fashion. Moreover, we investigate the problem of stabilizing the network when the curing rates of a limited number of nodes can be controlled. In particular, we characterize the number of controllers required for a class of undirected graphs. We also design optimal controllers capable of minimizing the total infection in the network at minimum cost. Finally, we outline a set of open problems in the area of information spread control.

Chess therapy: A new approach to curing panic attack.

PubMed

Barzegar, Kazem; Barzegar, Somayeh

2017-12-01

To study the effect of playing cell phone chess game on treating panic attack. The chess game on an android cell phone was played by the researcher who was affected by panic attack as a post-traumatic disorder immediately after or before feeling of the start of symptoms. The right level of difficulty, i.e., levels 2-4, was selected for optimal results. Playing chess game on the android cell phone prevented the manifestation of panic attack and led to the cure of this traumatic condition. Chess therapy with the right level of difficulty can be recommended as a very effective non-pharmaceutical method for the successful treatment of panic attacks. Copyright © 2017 Elsevier B.V. All rights reserved.

Optimizing the response to surveillance alerts in automated surveillance systems.

PubMed

Izadi, Masoumeh; Buckeridge, David L

2011-02-28

Although much research effort has been directed toward refining algorithms for disease outbreak alerting, considerably less attention has been given to the response to alerts generated from statistical detection algorithms. Given the inherent inaccuracy in alerting, it is imperative to develop methods that help public health personnel identify optimal policies in response to alerts. This study evaluates the application of dynamic decision making models to the problem of responding to outbreak detection methods, using anthrax surveillance as an example. Adaptive optimization through approximate dynamic programming is used to generate a policy for decision making following outbreak detection. We investigate the degree to which the model can tolerate noise theoretically, in order to keep near optimal behavior. We also evaluate the policy from our model empirically and compare it with current approaches in routine public health practice for investigating alerts. Timeliness of outbreak confirmation and total costs associated with the decisions made are used as performance measures. Using our approach, on average, 80 per cent of outbreaks were confirmed prior to the fifth day of post-attack with considerably less cost compared to response strategies currently in use. Experimental results are also provided to illustrate the robustness of the adaptive optimization approach and to show the realization of the derived error bounds in practice. Copyright © 2011 John Wiley & Sons, Ltd.

Research on the technology of detecting the SQL injection attack and non-intrusive prevention in WEB system

NASA Astrophysics Data System (ADS)

Hu, Haibin

2017-05-01

Among numerous WEB security issues, SQL injection is the most notable and dangerous. In this study, characteristics and procedures of SQL injection are analyzed, and the method for detecting the SQL injection attack is illustrated. The defense resistance and remedy model of SQL injection attack is established from the perspective of non-intrusive SQL injection attack and defense. Moreover, the ability of resisting the SQL injection attack of the server has been comprehensively improved through the security strategies on operation system, IIS and database, etc.. Corresponding codes are realized. The method is well applied in the actual projects.

Optimal eavesdropping in cryptography with three-dimensional quantum states.

PubMed

Bruss, D; Macchiavello, C

2002-03-25

We study optimal eavesdropping in quantum cryptography with three-dimensional systems, and show that this scheme is more secure against symmetric attacks than protocols using two-dimensional states. We generalize the according eavesdropping transformation to arbitrary dimensions, and discuss the connection with optimal quantum cloning.

Energy for the Warfighter: Operational Energy Strategy

DTIC Science & Technology

2011-05-01

logistics have proven vulnerable to attack in recent conflicts. Strategically, energy is important for economic stability and growth, with nations around...were wounded or killed in action from attacks on fuel and water resupply convoys.11 According to U.S. Transportation Command (USTRANSCOM), ground...convoys were attacked 1,100 times in 2010,12 and that may not count movements of fuel at the tactical level, from forward operating bases to patrol

Localized spatial and temporal attack dynamics of the mountain pine beetle in lodgepole pine. Forest Service research paper

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bentz, B.J.; Powell, J.A.; Logan, J.A.

1996-12-01

Colonization of a host tree by the mountain pine beetle (Dendroctonus ponderosae) involves chemical communication that enables a massive aggregation of beetles on a single resource, thereby ensuring host death and subsequent beetle population survival. Beetle populations have evolved a mechanism for termination of colonization on a lodgepole pine tree at optimal beetle densities, with a concomitant switch of attacks to nearby trees. Observations of the daily spatial and temporal attack process of mountain pine beetles (nonepidemic) attacking lodgepole pine suggest that beetles switch attacks to a new host tree before the original focus tree is fully colonized, and thatmore » verbenone, an antiaggregating pheromone, may be acting within a tree rather than between trees.« less

Wrap-Attack Pack: Product Packaging Exercise

ERIC Educational Resources Information Center

Lee, Seung Hwan; Hoffman, K. Douglas

2016-01-01

Although many marketing courses discuss traditional concepts pertaining to product strategy, concepts specifically relating to packaging are often glossed over. This exercise, "Wrap-Attack Pack," teaches students about the utilitarian and hedonic design elements of packaging. More specifically, the primary objective is to creatively…

Terrorism threats and preparedness in Canada: the perspective of the Canadian public.

PubMed

Gibson, Stacey; Lemyre, Louise; Clément, Mélanie; Markon, Marie-Pierre L; Lee, Jennifer E C

2007-06-01

Although Canada has not experienced a major terrorist attack, an increased global pending threat has put preparedness at the top of the Canadian government's agenda. Given its strong multicultural community and close proximity to the recently targeted United States, the Canadian experience is unique. However, minimal research exists on the public's reactions to terrorism threats and related preparedness strategies. In order for response initiatives to be optimally effective, it is important that the public's opinions regarding terrorism and preparedness be considered. This qualitative study examined perceptions of terrorism threats among Canadians living in Central and Eastern Canada (N = 75) in the fall of 2004. Conceptualizations of terrorism threat, psychosocial impacts, and sense of preparedness were explored in a series of qualitative interviews. Findings revealed that the majority of Canadians did not feel overly threatened by terrorist attacks, due in part to a perception of terrorist threats as related to global sociopolitical events and a positive Canadian identity. In addition, while most respondents did not feel they were individually affected by the threat of terrorism, there was some concern regarding larger societal impacts, such as increased paranoia, discrimination, and threats to civil liberties. Participants' views on preparedness focused largely on the utility of emergency preparedness strategies and the factors that could mitigate or inhibit preparedness at the individual and institutional levels, with a specific focus on education. Finally, the significant relevance of these findings in shaping terrorism preparedness, both in Canada and generally, is discussed.

A Game Theoretic Model for the Optimal Disposition of Integrated Air Defense System Assets

DTIC Science & Technology

2015-03-26

fellows of Miami Valley Philosophical and Lifting Society v Acknowledgements I want to thank LTC Brian J. Lunday and Lt Col Matthew J. Robbins for...on the defender’s valuation of tar- gets. However, if we assume that Hamas, the attacker, knows the layout of Israel’s defense, they may attack

Behavioral Strategies of Phorid Parasitoids and Responses of Their Hosts, the Leaf-Cutting Ants

PubMed Central

Elizalde, Luciana; Folgarait, Patricia Julia

2012-01-01

Host-searching and oviposition behaviors of parasitoids, and defensive responses of the hosts, are fundamental in shaping the ecology of host-parasitoid interactions. In order to uncover key behavioral features for the little known interactions between phorid parasitoids (Diptera: Phoridae) and their leaf-cutting ant hosts (Formicidae: Attini), host-related behavioral strategies (i.e., host searching and oviposition) for 13 phorid species, and host defensive responses (i.e., hitchhikers and particular body postures) for 11 ant species, were studied. Data was collected at 14 localities, one of them characterized by its high species richness for this host-parasitoid system. Phorid species showed both great variation and specificity in attacking behaviors. Some chose their hosts using either an ambush or an actively searching strategy, while some species attacked ants on different body parts, and specialized on ants performing different tasks, such as when ants were foraging, removing wastes to refuse piles, or repairing the nest. Combining all the behaviors recorded, most phorid species differed in performance in at least one, making it possible to recognize species in the field through their behavior. Phorid species that attacked hosts with greater activity levels showed overall higher attack rates, although there was no significant correlation between attack rates by most phorid species and ant activity outside the nest while parasitoids were attacking. The presence of phorids was a significant determinant for the presence of defensive behaviors by the ants. Although ant species varied in the incidence levels of these defensive behaviors, most ant species reacted against different phorids by utilizing similar behaviors, in contrast to what parasitoids do. General features of the observed phorid-ant interactions were parasitoid specialization and corresponding high interspecific variation in their behaviors, while their hosts showed generalized responses to attacks with high intraspecific variation. Behavioral patterns as well as specific features of these ant-parasitoid interactions are described, and their ecological importance discussed. PMID:23448343

Coupled Inverted Pendula Model of Competition and Cooperation

NASA Astrophysics Data System (ADS)

Yoshida, Katsutoshi; Ohta, Hiroki

A coupled inverted pendula model of competition and cooperation is proposed to develop a purely mechanical implementation comparable to the Lotka-Volterra competition model. It is shown numerically that the proposed model can produce the four stable equilibriums analogous to ecological coexistence, two states of dominance, and scramble. The authors also propose two types of open-loop strategies to switch the equilibriums. The proposed strategies can be associated with an attack and a counter attack of agents through a metaphor of martial arts.

Modeling and Managing Risk in Billing Infrastructures

NASA Astrophysics Data System (ADS)

Baiardi, Fabrizio; Telmon, Claudio; Sgandurra, Daniele

This paper discusses risk modeling and risk management in information and communications technology (ICT) systems for which the attack impact distribution is heavy tailed (e.g., power law distribution) and the average risk is unbounded. Systems with these properties include billing infrastructures used to charge customers for services they access. Attacks against billing infrastructures can be classified as peripheral attacks and backbone attacks. The goal of a peripheral attack is to tamper with user bills; a backbone attack seeks to seize control of the billing infrastructure. The probability distribution of the overall impact of an attack on a billing infrastructure also has a heavy-tailed curve. This implies that the probability of a massive impact cannot be ignored and that the average impact may be unbounded - thus, even the most expensive countermeasures would be cost effective. Consequently, the only strategy for managing risk is to increase the resilience of the infrastructure by employing redundant components.

Strategies for Preparing United States Combat Organizations for the Inevitability of Casualties

DTIC Science & Technology

2012-06-08

heart, nausea and diarrhea , and anxiety and indecisiveness (Bethea 2010, 79). These mild stress reactions seem to align with what is occurring during...The technique used to exercise combat fear inoculation was by requesting the cooperation of police attack dogs . The members of de Beckers...organization all became attack dog victims by donning the appropriate protective gear and allowing attack dogs to have their way with them. Grossman explains

Progress and Challenges in Macroencapsulation Approaches for Type 1 Diabetes (T1D) Treatment: Cells, Biomaterials, and Devices

PubMed Central

Song, Shang; Roy, Shuvo

2018-01-01

Macroencapsulation technology has been an attractive topic in the field of treatment for Type 1 diabetes due to mechanical stability, versatility, and retrievability of the macrocapsule design. Macro-capsules can be categorized into extravascular and intravascular devices, in which solute transport relies either on diffusion or convection, respectively. Failure of macroencapsulation strategies can be due to limited regenerative capacity of the encased insulin-producing cells, sub-optimal performance of encapsulation biomaterials, insufficient immunoisolation, excessive blood thrombosis for vascular perfusion devices, and inadequate modes of mass transfer to support cell viability and function. However, significant technical advancements have been achieved in macroencapsulation technology, namely reducing diffusion distance for oxygen and nutrients, using pro-angiogenic factors to increase vascularization for islet engraftment, and optimizing membrane permeability and selectivity to prevent immune attacks from host’s body. This review presents an overview of existing macroencapsulation devices and discusses the advances based on tissue-engineering approaches that will stimulate future research and development of macroencapsulation technology. PMID:26615050

A framework for developing and integrating effective routing strategies within the emergency management decision-support system : [research brief].

DOT National Transportation Integrated Search

2012-05-01

The terrorist attacks on September 11th, as well as other coordinated attacks on transit centers in Madrid and London, have underscored the importance of evacuation planning to : transportation professionals. With computer technology advancement, urb...

Anti-Immune Strategies of Pathogenic Fungi

PubMed Central

Marcos, Caroline M.; de Oliveira, Haroldo C.; de Melo, Wanessa de Cássia M. Antunes; da Silva, Julhiany de Fátima; Assato, Patrícia A.; Scorzoni, Liliana; Rossi, Suélen A.; de Paula e Silva, Ana C. A.; Mendes-Giannini, Maria J. S.; Fusco-Almeida, Ana M.

2016-01-01

Pathogenic fungi have developed many strategies to evade the host immune system. Multiple escape mechanisms appear to function together to inhibit attack by the various stages of both the adaptive and the innate immune response. Thus, after entering the host, such pathogens fight to overcome the immune system to allow their survival, colonization and spread to different sites of infection. Consequently, the establishment of a successful infectious process is closely related to the ability of the pathogen to modulate attack by the immune system. Most strategies employed to subvert or exploit the immune system are shared among different species of fungi. In this review, we summarize the main strategies employed for immune evasion by some of the major pathogenic fungi. PMID:27896220

A quantum optical firewall based on simple quantum devices

NASA Astrophysics Data System (ADS)

Amellal, H.; Meslouhi, A.; Hassouni, Y.; El Baz, M.

2015-07-01

In order to enhance the transmission security in quantum communications via coherent states, we propose a quantum optical firewall device to protect a quantum cryptosystem against eavesdropping through optical attack strategies. Similar to the classical model of the firewall, the proposed device gives legitimate users the possibility of filtering, controlling (input/output states) and making a decision (access or deny) concerning the traveling states. To prove the security and efficiency of the suggested optical firewall, we analyze its performances against the family of intercept and resend attacks, especially against one of the most prominent attack schemes known as "Faked State Attack."

Weight Stigma Goes Viral on the Internet: Systematic Assessment of YouTube Comments Attacking Overweight Men and Women

PubMed Central

Hale, Brent; Knackmuhs, Eric; Mackert, Michael

2018-01-01

Background Anonymous verbal attacks against overweight individuals on social media are common and widespread. These comments often use negative, misogynist, or derogatory words, which stigmatize the targeted individuals with obesity. These verbal attacks may cause depression in overweight individuals, which could subsequently promote unhealthy eating behavior (ie, binge eating) and further weight gain. To develop an intervention policy and strategies that tackle the anonymous, Web-based verbal attacks, a thorough understanding of the comments is necessary. Objective This study aimed to examine how anonymous users verbally attack or defend overweight individuals in terms of 3 themes: (1) topic of verbal attack (ie, what aspects of overweight individuals are verbally attacked), (2) gender of commenters and targeted overweight individuals, and (3) intensity of derogation depending on the targeted gender (ie, the number of swear words used within comments). Methods This study analyzed the content of YouTube comments that discuss overweight individuals or groups from 2 viral videos, titled “Fat Girl Tinder Date” and “Fat Guy Tinder Date.” The twin videos provide an avenue through which to analyze discussions of obesity as they organically occurred in a contemporary setting. We randomly sampled and analyzed 320 comments based on a coding instrument developed for this study. Results First, there were twice as many comments verbally attacking overweight individuals (n=174) than comments defending them (n=89). Second, overweight women are attacked for their capacities (eg, laziness, maturity; 14/51, 28%), whereas overweight men are attacked for their heterosocial skills (eg, rudeness, annoyance; 24/29, 83%). Third, the majority of commenters who attacked overweight women are male (42/52, 81%). Fourth, attacking comments generated toward overweight women included more swear words (mean 0.44, SD 0.77) than those targeting men (mean 0.23, SD 0.48). Conclusions Our data elucidate a worrying situation of frequent disinhibited aggressive messages against overweight individuals online. Importantly, the patterns of verbal aggression differ depending on the gender of the targeted overweight individuals. Thus, gender-tailored intervention strategies that specifically tackle Internet users’ verbal aggression against overweight individuals need to be developed. PMID:29559426

Image counter-forensics based on feature injection

NASA Astrophysics Data System (ADS)

Iuliani, M.; Rossetto, S.; Bianchi, T.; De Rosa, Alessia; Piva, A.; Barni, M.

2014-02-01

Starting from the concept that many image forensic tools are based on the detection of some features revealing a particular aspect of the history of an image, in this work we model the counter-forensic attack as the injection of a specific fake feature pointing to the same history of an authentic reference image. We propose a general attack strategy that does not rely on a specific detector structure. Given a source image x and a target image y, the adversary processes x in the pixel domain producing an attacked image ~x, perceptually similar to x, whose feature f(~x) is as close as possible to f(y) computed on y. Our proposed counter-forensic attack consists in the constrained minimization of the feature distance Φ(z) =│ f(z) - f(y)│ through iterative methods based on gradient descent. To solve the intrinsic limit due to the numerical estimation of the gradient on large images, we propose the application of a feature decomposition process, that allows the problem to be reduced into many subproblems on the blocks the image is partitioned into. The proposed strategy has been tested by attacking three different features and its performance has been compared to state-of-the-art counter-forensic methods.

Timing of cyber conflict.

PubMed

Axelrod, Robert; Iliev, Rumen

2014-01-28

Nations are accumulating cyber resources in the form of stockpiles of zero-day exploits as well as other novel methods of engaging in future cyber conflict against selected targets. This paper analyzes the optimal timing for the use of such cyber resources. A simple mathematical model is offered to clarify how the timing of such a choice can depend on the stakes involved in the present situation, as well as the characteristics of the resource for exploitation. The model deals with the question of when the resource should be used given that its use today may well prevent it from being available for use later. The analysis provides concepts, theory, applications, and distinctions to promote the understanding strategy aspects of cyber conflict. Case studies include the Stuxnet attack on Iran's nuclear program, the Iranian cyber attack on the energy firm Saudi Aramco, the persistent cyber espionage carried out by the Chinese military, and an analogous case of economic coercion by China in a dispute with Japan. The effects of the rapidly expanding market for zero-day exploits are also analyzed. The goal of the paper is to promote the understanding of this domain of cyber conflict to mitigate the harm it can do, and harness the capabilities it can provide.

Cyber War Game in Temporal Networks

DTIC Science & Technology

2016-02-09

Boston, Massachusetts 02115, United States of America * jianxi.gao@gmail.com Abstract In a cyber war game where a network is fully distributed and... game with minimum effort. Given the system goal states of attackers and defenders, we study what strategies attackers or defenders can take to reach

Optimal attacks on qubit-based Quantum Key Recycling

NASA Astrophysics Data System (ADS)

Leermakers, Daan; Škorić, Boris

2018-03-01

Quantum Key Recycling (QKR) is a quantum cryptographic primitive that allows one to reuse keys in an unconditionally secure way. By removing the need to repeatedly generate new keys, it improves communication efficiency. Škorić and de Vries recently proposed a QKR scheme based on 8-state encoding (four bases). It does not require quantum computers for encryption/decryption but only single-qubit operations. We provide a missing ingredient in the security analysis of this scheme in the case of noisy channels: accurate upper bounds on the required amount of privacy amplification. We determine optimal attacks against the message and against the key, for 8-state encoding as well as 4-state and 6-state conjugate coding. We provide results in terms of min-entropy loss as well as accessible (Shannon) information. We show that the Shannon entropy analysis for 8-state encoding reduces to the analysis of quantum key distribution, whereas 4-state and 6-state suffer from additional leaks that make them less effective. From the optimal attacks we compute the required amount of privacy amplification and hence the achievable communication rate (useful information per qubit) of qubit-based QKR. Overall, 8-state encoding yields the highest communication rates.

Decomposition technique and optimal trajectories for the aeroassisted flight experiment

NASA Technical Reports Server (NTRS)

Miele, A.; Wang, T.; Deaton, A. W.

1990-01-01

An actual geosynchronous Earth orbit-to-low Earth orbit (GEO-to-LEO) transfer is considered with reference to the aeroassisted flight experiment (AFE) spacecraft, and optimal trajectories are determined by minimizing the total characteristic velocity. The optimization is performed with respect to the time history of the controls (angle of attack and angle of bank), the entry path inclination and the flight time being free. Two transfer maneuvers are considered: direct ascent (DA) to LEO and indirect ascent (IA) to LEO via parking Earth orbit (PEO). By taking into account certain assumptions, the complete system can be decoupled into two subsystems: one describing the longitudinal motion and one describing the lateral motion. The angle of attack history, the entry path inclination, and the flight time are determined via the longitudinal motion subsystem. In this subsystem, the difference between the instantaneous bank angle and a constant bank angle is minimized in the least square sense subject to the specified orbital inclination requirement. Both the angles of attack and the angle of bank are shown to be constant. This result has considerable importance in the design of nominal trajectories to be used in the guidance of AFE and aeroassisted orbital transfer (AOT) vehicles.

The Future of Air Power in the Aftermath of the Gulf War

DTIC Science & Technology

1992-07-01

strategic-nuclear capabilities, for which the deterrence of direct nuclear attack against the United States itself was always a lesser-included case of a...conflicts, when there are only low-value, low-contrast targets in most cases . In regard to the 20 US MILITARY STRATEGY geographic setting, the attack...navigated over their intended targets to drop laser-guided glide bombs within three feet of the aim points, with the concurrent filming of the attack

Invisible Trojan-horse attack.

PubMed

Sajeed, Shihan; Minshull, Carter; Jain, Nitin; Makarov, Vadim

2017-08-21

We demonstrate the experimental feasibility of a Trojan-horse attack that remains nearly invisible to the single-photon detectors employed in practical quantum key distribution (QKD) systems, such as Clavis2 from ID Quantique. We perform a detailed numerical comparison of the attack performance against Scarani-Ac´ın-Ribordy-Gisin (SARG04) QKD protocol at 1924 nm versus that at 1536 nm. The attack strategy was proposed earlier but found to be unsuccessful at the latter wavelength, as reported in N. Jain et al., New J. Phys. 16, 123030 (2014). However at 1924 nm, we show experimentally that the noise response of the detectors to bright pulses is greatly reduced, and show by modeling that the same attack will succeed. The invisible nature of the attack poses a threat to the security of practical QKD if proper countermeasures are not adopted.

Synthesis and acid digestion of biomorphic ceramics: determination of alkaline and alkaline earth ions.

PubMed

Bosch Ojeda, Catalina; Sánchez Rojas, Fuensanta; Cano Pavón, José Manuel

2007-09-01

Ceramic and glass are some of the more recent engineering materials and those that are most resistant to environmental conditions. They belong to advanced materials in that they are being developed for the aerospace and electronics industries. In the last decade, a new class of ceramic materials has been the focus of particular attention. The materials were produced with natural, renewable resources (wood or wood-based products). In this work, we have synthesised a new biomorphic ceramic material from oak wood and Si infiltration. After the material characterization, we have optimized the dissolution of the sample by acid attack in an oven under microwave irradiation. Experimental designs were used as a multivariate strategy for the evaluation of the effects of varying several variables at the same time. The optimization was performed in two steps using factorial design for preliminary evaluation and a Draper-Lin design for determination of the critical experimental conditions. Five variables (time, power, volume of HNO3, volume H2SO4 and volume of HF) were considered as factors and as a response the concentration of different metal ions in the optimization process. Interactions between analytical factors and their optimal levels were investigated using a Draper-Lin design.

Optimizing the robustness of electrical power systems against cascading failures.

PubMed

Zhang, Yingrui; Yağan, Osman

2016-06-21

Electrical power systems are one of the most important infrastructures that support our society. However, their vulnerabilities have raised great concern recently due to several large-scale blackouts around the world. In this paper, we investigate the robustness of power systems against cascading failures initiated by a random attack. This is done under a simple yet useful model based on global and equal redistribution of load upon failures. We provide a comprehensive understanding of system robustness under this model by (i) deriving an expression for the final system size as a function of the size of initial attacks; (ii) deriving the critical attack size after which system breaks down completely; (iii) showing that complete system breakdown takes place through a first-order (i.e., discontinuous) transition in terms of the attack size; and (iv) establishing the optimal load-capacity distribution that maximizes robustness. In particular, we show that robustness is maximized when the difference between the capacity and initial load is the same for all lines; i.e., when all lines have the same redundant space regardless of their initial load. This is in contrast with the intuitive and commonly used setting where capacity of a line is a fixed factor of its initial load.

Effects of Motivation: Rewarding Hackers for Undetected Attacks Cause Analysts to Perform Poorly.

PubMed

Maqbool, Zahid; Makhijani, Nidhi; Pammi, V S Chandrasekhar; Dutt, Varun

2017-05-01

The aim of this study was to determine how monetary motivations influence decision making of humans performing as security analysts and hackers in a cybersecurity game. Cyberattacks are increasing at an alarming rate. As cyberattacks often cause damage to existing cyber infrastructures, it is important to understand how monetary rewards may influence decision making of hackers and analysts in the cyber world. Currently, only limited attention has been given to this area. In an experiment, participants were randomly assigned to three between-subjects conditions ( n = 26 for each condition): equal payoff, where the magnitude of monetary rewards for hackers and defenders was the same; rewarding hacker, where the magnitude of monetary reward for hacker's successful attack was 10 times the reward for analyst's successful defense; and rewarding analyst, where the magnitude of monetary reward for analyst's successful defense was 10 times the reward for hacker's successful attack. In all conditions, half of the participants were human hackers playing against Nash analysts and half were human analysts playing against Nash hackers. Results revealed that monetary rewards for human hackers and analysts caused a decrease in attack and defend actions compared with the baseline. Furthermore, rewarding human hackers for undetected attacks made analysts deviate significantly from their optimal behavior. If hackers are rewarded for their undetected attack actions, then this causes analysts to deviate from optimal defend proportions. Thus, analysts need to be trained not become overenthusiastic in defending networks. Applications of our results are to networks where the influence of monetary rewards may cause information theft and system damage.

Using agility to combat cyber attacks.

PubMed

Anderson, Kerry

2017-06-01

Some incident response practitioners feel that they have been locked in a battle with cyber criminals since the popular adoption of the internet. Initially, organisations made great inroads in preventing and containing cyber attacks. In the last few years, however, cyber criminals have become adept at eluding defence security technologies and rapidly modifying their exploit strategies for financial or political gains. Similar to changes in military combat tactics, cyber criminals utilise distributed attack cells, real-time communications, and rapidly mutating exploits to minimise the potential for detection. Cyber criminals have changed their attack paradigm. This paper describes a new incident response paradigm aimed at combating the new model of cyber attacks with an emphasis on agility to increase the organisation's ability to respond rapidly to these new challenges.

Coping of school-age children in the sealed room during scud missile bombardment and postwar stress reactions.

PubMed

Weisenberg, M; Schwarzwald, J; Waysman, M; Solomon, Z; Klingman, A

1993-06-01

Children's coping behaviors in the sealed room (a shelter against chemical and biological weapons) during scud missile attacks in the Persian Gulf war were examined in relation to postwar stress reactions. Three weeks after the war, 5th, 7th, and 10th graders (N = 492) completed questionnaires assessing coping behaviors and emotional responses in the sealed room, as well as current stress reactions and posttraumatic stress disorder (PTSD). Despite an underlying feeling of tension, the dominant emotional stance in the sealed room was one of detached optimism. Common forms of coping involved information seeking, checking, and wishful thinking. Emotion-focused coping such as avoidance and distraction strategies was associated with less postwar stress reactions than persistence at direct problem-focused actions once the minimal actions available had been undertaken. Fifth graders were found to use less emotion-focused and more problem-focused coping strategies than were the 7th and 10th graders.

Optimization of armored spherical tanks for storage on the lunar surface

NASA Technical Reports Server (NTRS)

Bents, D. J.; Knight, D. A.

1992-01-01

A redundancy strategy for reducing micrometeroid armoring mass is investigated, with application to cryogenic reactant storage for a regenerative fuel cell (RFC) on the lunar surface. In that micrometeoroid environment, the cryogenic fuel must be protected from loss due to tank puncture. The tankage must have a sufficiently high probability of survival over the length of the mission so that the probability of system failure due to tank puncture is low compared to the other mission risk factors. Assuming that a single meteoroid penetration can cause a storage tank to lose its contents, two means are available to raise the probability of surviving micrometeoroid attack to the desired level. One can armor the tanks to a thickness sufficient to reduce probability of penetration of any tank to the desired level or add extra capacity in the form of space tanks that results in survival of a given number out of the ensemble at the desired level. A combination of these strategies (armor and redundancy) is investigated.

Contemporary best practice in the evaluation and management of stuttering priapism.

PubMed

Kousournas, Georgios; Muneer, Asif; Ralph, David; Zacharakis, Evangelos

2017-01-01

Stuttering priapism is rare and under-investigated clinical entity. Although it shares similarities with ischaemic priapism, by definition, stuttering priapism has distinct characteristics that advocate for a different management in the clinical setting. Therefore, the management of stuttering priapism aims primarily to prevent recurrence rather than the resolution of spontaneous attacks. A multimodal approach and the individualization of each case are essential because of the diversity of the condition and the plethora of proposed therapeutic strategies. Understanding the underlying pathophysiology and familiarity with contemporary, past and emerging future agents and therapeutic options are required in order to provide an optimal solution for each patient. In addition, patient counselling and the option to combine therapeutic strategies and challenge second-line therapies are essential weapons in the armament of the urologist. Although further clinical trials and studies are mandatory in order to obtain solid data and provide recommendations, all therapeutic options are analysed, with specific interest in the potential advantages and disadvantages. A structured evaluation procedure is also described.

Behavioral Treatment of Mucous Colitis

ERIC Educational Resources Information Center

Youell, Katherine J.; McCullough, James P.

1975-01-01

A 22-year-old female graduate student who suffered colitis attacks at the onset of therapy was apparently successfully treated by a procedure in which the therapist labeled antecedent stress events that appeared to be precipitating the attacks. The client was then taught a behavioral coping strategy to counter the stress events. (Author)

Robust Structural Analysis and Design of Distributed Control Systems to Prevent Zero Dynamics Attacks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weerakkody, Sean; Liu, Xiaofei; Sinopoli, Bruno

We consider the design and analysis of robust distributed control systems (DCSs) to ensure the detection of integrity attacks. DCSs are often managed by independent agents and are implemented using a diverse set of sensors and controllers. However, the heterogeneous nature of DCSs along with their scale leave such systems vulnerable to adversarial behavior. To mitigate this reality, we provide tools that allow operators to prevent zero dynamics attacks when as many as p agents and sensors are corrupted. Such a design ensures attack detectability in deterministic systems while removing the threat of a class of stealthy attacks in stochasticmore » systems. To achieve this goal, we use graph theory to obtain necessary and sufficient conditions for the presence of zero dynamics attacks in terms of the structural interactions between agents and sensors. We then formulate and solve optimization problems which minimize communication networks while also ensuring a resource limited adversary cannot perform a zero dynamics attacks. Polynomial time algorithms for design and analysis are provided.« less

Extended analysis of the Trojan-horse attack in quantum key distribution

NASA Astrophysics Data System (ADS)

Vinay, Scott E.; Kok, Pieter

2018-04-01

The discrete-variable quantum key distribution protocols based on the 1984 protocol of Bennett and Brassard (BB84) are known to be secure against an eavesdropper, Eve, intercepting the flying qubits and performing any quantum operation on them. However, these protocols may still be vulnerable to side-channel attacks. We investigate the Trojan-horse side-channel attack where Eve sends her own state into Alice's apparatus and measures the reflected state to estimate the key. We prove that the separable coherent state is optimal for Eve among the class of multimode Gaussian attack states, even in the presence of thermal noise. We then provide a bound on the secret key rate in the case where Eve may use any separable state.

Novel Psychological Formulation and Treatment of "Tic Attacks" in Tourette Syndrome.

PubMed

Robinson, Sally; Hedderly, Tammy

2016-01-01

One important, but underreported, phenomenon in Tourette syndrome (TS) is the occurrence of "tic attacks." These episodes have been described at conferences as sudden bouts of tics and/or functional tic-like movements, lasting from 15 min to several hours. They have also been described by patients in online TS communities. To date, there are no reports of tic attacks in the literature. The aim of this article is to stimulate discussion and inform clinical practices by describing the clinical presentation of 12 children (mean age 11 years and 3 months; SD = 2 years and 4 months) with TS and tic attacks, with a detailed case report for one case (13-year-old male). These children commonly present acutely to casualty departments and undergo unnecessary medical investigations. Interestingly, all children reported comorbid anxiety, with worries about the tics themselves and an increased internal focus of attention on tics once the attacks had started. In keeping with other children, the index case reported a strong internal focus of attention, with a relationship between physiological sensations/tic urges, worries about having tic attacks, and behavioral responses (e.g., body scanning, situational avoidance, and other responses). In our experience, the attacks reduce with psychological therapy, for example, the index case attended 13 sessions of therapy that included metacognitive and attention training techniques, as well as cognitive-behavioral strategies. Following treatment, an improvement was seen across a range of measures assessing tics, mood, anxiety, and quality of life. Thus, psychological techniques used to treat anxiety disorders are effective at supporting a reduction in tic attacks through modifying attention, worry processes, and negative beliefs. It is hypothesized that an attentional style of threat monitoring, difficulties tolerating internal sensory urges, cognitive misattributions, and maladaptive coping strategies contribute to the onset and maintenance of tic attacks. These cases provide support for the view that tic attacks are triggered and maintained by psychological factors, thereby challenging the view that tic attacks merely reflect extended bouts of tics. As such, we propose that the movements seen in tic attacks may resemble a combination of tics and functional neurological movements, with tic attacks reflecting episodes of panic and anxiety for individuals with TS.

Multicasting for all-optical multifiber networks

NASA Astrophysics Data System (ADS)

Kã¶Ksal, Fatih; Ersoy, Cem

2007-02-01

All-optical wavelength-routed WDM WANs can support the high bandwidth and the long session duration requirements of the application scenarios such as interactive distance learning or on-line diagnosis of patients simultaneously in different hospitals. However, multifiber and limited sparse light splitting and wavelength conversion capabilities of switches result in a difficult optimization problem. We attack this problem using a layered graph model. The problem is defined as a k-edge-disjoint degree-constrained Steiner tree problem for routing and fiber and wavelength assignment of k multicasts. A mixed integer linear programming formulation for the problem is given, and a solution using CPLEX is provided. However, the complexity of the problem grows quickly with respect to the number of edges in the layered graph, which depends on the number of nodes, fibers, wavelengths, and multicast sessions. Hence, we propose two heuristics layered all-optical multicast algorithm [(LAMA) and conservative fiber and wavelength assignment (C-FWA)] to compare with CPLEX, existing work, and unicasting. Extensive computational experiments show that LAMA's performance is very close to CPLEX, and it is significantly better than existing work and C-FWA for nearly all metrics, since LAMA jointly optimizes routing and fiber-wavelength assignment phases compared with the other candidates, which attack the problem by decomposing two phases. Experiments also show that important metrics (e.g., session and group blocking probability, transmitter wavelength, and fiber conversion resources) are adversely affected by the separation of two phases. Finally, the fiber-wavelength assignment strategy of C-FWA (Ex-Fit) uses wavelength and fiber conversion resources more effectively than the First Fit.

How moths escape bats: predicting outcomes of predator-prey interactions.

PubMed

Corcoran, Aaron J; Conner, William E

2016-09-01

What determines whether fleeing prey escape from attacking predators? To answer this question, biologists have developed mathematical models that incorporate attack geometries, pursuit and escape trajectories, and kinematics of predator and prey. These models have rarely been tested using data from actual predator-prey encounters. To address this problem, we recorded multi-camera infrared videography of bat-insect interactions in a large outdoor enclosure. We documented 235 attacks by four Myotis volans bats on a variety of moths. Bat and moth flight trajectories from 50 high-quality attacks were reconstructed in 3-D. Despite having higher maximum velocity, deceleration and overall turning ability, bats only captured evasive prey in 69 of 184 attacks (37.5%); bats captured nearly all moths not evading attack (50 of 51; 98%). Logistic regression indicated that prey radial acceleration and escape angle were the most important predictors of escape success (44 of 50 attacks correctly classified; 88%). We found partial support for the turning gambit mathematical model; however, it underestimated the escape threshold by 25% of prey velocity and did not account for prey escape angle. Whereas most prey escaping strikes flee away from predators, moths typically escaped chasing bats by turning with high radial acceleration toward 'safety zones' that flank the predator. This strategy may be widespread in prey engaged in chases. Based on these findings, we developed a novel geometrical model of predation. We discuss implications of this model for the co-evolution of predator and prey kinematics and pursuit and escape strategies. © 2016. Published by The Company of Biologists Ltd.

Successful attack on permutation-parity-machine-based neural cryptography.

PubMed

Seoane, Luís F; Ruttor, Andreas

2012-02-01

An algorithm is presented which implements a probabilistic attack on the key-exchange protocol based on permutation parity machines. Instead of imitating the synchronization of the communicating partners, the strategy consists of a Monte Carlo method to sample the space of possible weights during inner rounds and an analytic approach to convey the extracted information from one outer round to the next one. The results show that the protocol under attack fails to synchronize faster than an eavesdropper using this algorithm.

Improving the multiparty quantum secret sharing over two collective-noise channels against insider attack

NASA Astrophysics Data System (ADS)

Sun, Ying; Wen, Qiao-yan; Zhu, Fu-chen

2010-01-01

The security of the multiparty quantum secret sharing protocol presented by Zhang [Z.J. Zhang, Physica A, 361 (2006) 233] is analyzed. It is shown that this protocol is vulnerable to the insider attack since eavesdropping detection is performed only when all states arrive at the last agent. We propose an attack strategy and give an improved version of the original protocol. The improved protocol is robust and has the same traits with the original one.

Shark attack-related injuries: Epidemiology and implications for plastic surgeons.

PubMed

Ricci, Joseph A; Vargas, Christina R; Singhal, Dhruv; Lee, Bernard T

2016-01-01

The increased media attention to shark attacks has led to a heightened fear and public awareness. Although few sharks are considered dangerous, attacks on humans can result in large soft tissue defects necessitating the intervention of reconstructive surgeons. This study aims to evaluate and describe the characteristics of shark-related injuries in order to improve treatment. The Global Shark Accident File, maintained by the Shark Research Institute (Princeton, NJ, USA), is a compilation of all known worldwide shark attacks. Database records since the 1900s were reviewed to identify differences between fatal and nonfatal attacks, including: geography, injury pattern, shark species, and victim activity. Since the 1900s, there have been 5034 reported shark attacks, of which 1205 (22.7%) were fatal. Although the incidence of attacks per decade has increased, the percentage of fatalities has decreased. Characteristics of fatal attacks included swimming (p = 0.001), boating (p = 0.001), three or more bite sites (p = 0.03), limb loss (p = 0.001), or tiger shark attack (p = 0.002). The most common attacks were bites to the legs (41.8%) or arms (18.4%), with limb loss occurring in 7% of attacks. Geographically, the majority of attacks occurred in North America (36.7%) and Australia (26.5%). Most attacks in the USA occurred in Florida (49.1%) and California (13.6%). Although rare, shark attacks result in devastating injuries to patients. As these injuries often involve multiple sites and limb loss, this creates a significant challenge for reconstructive surgeons. Proper identification of the characteristics of the attack can aid in providing optimal care for those affected. Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Computing The No-Escape Envelope Of A Short-Range Missile

NASA Technical Reports Server (NTRS)

Neuman, Frank

1991-01-01

Method for computing no-escape envelope of short-range air-to-air missile devised. Useful for analysis of both strategies for avoidance and strategies for attack. With modifications, also useful in analysis of control strategies for one-on-one air-to-air combat, or wherever multiple control strategies considered.

Management of children and young people (CYP) with asthma: a clinical audit report.

PubMed

Levy, Mark L; Ward, Angela; Nelson, Sara

2018-05-21

An asthma attack or exacerbation signals treatment failure. Most attacks are preventable and failure to recognize risk of asthma attacks are well recognized as risk factors for future attacks and even death. Of the 19 recommendations made by the United Kingdom National Review of Asthma Deaths (NRAD) (1) only one has been partially implemented-a National Asthma Audit; however, this hasn't reported yet. The Harrow Clinical Commissioning Group (CCG) in London implemented a clinical asthma audit on 291 children and young people aged under 19 years (CYP) who had been treated for asthma attacks in 2016. This was funded as a Local Incentive Scheme (LIS) aimed at improving quality health care delivery. Two years after the publication of the NRAD report it is surprising that risks for future attacks were not recognized, that few patients were assessed objectively during attacks and only 10% of attacks were followed up within 2 days. However, it is encouraging that CYP hospital admissions following the audit were reduced by 16%, with clear benefit for patients, their families and the local health economy. This audit has provided an example of how clinicians can focus learning on patients who have had asthma attacks and utilize these events as a catalyst for active reflection in particular on modifiable risk factors. Through identification of these risks and active optimization of management, preventable asthma attacks could become 'never events'.

[Terrorist attack trauma - an individual entity of polytrauma : A 10-year update].

PubMed

Güsgen, C; Franke, A; Hentsch, S; Kollig, E; Schwab, R

2017-10-01

The incidence of terrorist attacks is increasing worldwide, and they have also become a permanent threat in European cities. Due to its complexity, terrorist attack trauma places high demands on the strategy of surgical treatment. The combination of various mechanisms, explosions and gunshot injuries, with the characteristic pressure (blast) damage and a high proportion of penetrating trauma with simultaneous burns are characteristic features. Unlike in military conflicts, injuries to people of all ages and without ballistic body protection (body armor) are to be expected. The mechanism of the attack and its local conditions are of relevance for the assessment of the situation and the expected injury patterns. Thus, suicide attacks result in several times higher numbers of fatalities and casualties. Explosions on free ground lead to different types of injury than those in closed or semi-enclosed spaces. The treatment principles of the Advanced Trauma Life Support (ATLS®) are based on the intrahospital care of casualties as well as damage control strategies with trigger factors. In order to prepare and educate clinics and surgeons in Germany for such scenarios, various course formats of the professional societies, the German Society for General and Visceral Surgery (DGAV) and the German Society for Trauma Surgery (DGU) have now been established.

Why AIDS? The Mystery of How HIV Attacks the Immune System.

ERIC Educational Resources Information Center

Christensen, Damaris

1999-01-01

Reviews differing theories surrounding the mystery of how human immunodeficiency virus (HIV) attacks the immune system. Claims that understanding how HIV triggers immune-cell depletion may enable researchers to block its effects. New knowledge could reveal strategies for acquired immune deficiency syndrome (AIDS) therapies that go beyond the drugs…

A Typology of Retaliation Strategies against Social Aggression among Adolescent Girls

ERIC Educational Resources Information Center

Kozlowski, Karen Phelan; Warber, Kathleen M.

2010-01-01

Girls respond to peer attacks of indirect social aggression in various ways. This study explores when and how victims retaliate against their aggressors. Qualitative interviews with 15 adolescent girls ages 10-16 suggest that victims of social aggression are likely to retaliate when their aggressors communicate the following: identity attacks,…

Mitigating Higher Ed Cyber Attacks

ERIC Educational Resources Information Center

Rogers, Gary; Ashford, Tina

2015-01-01

In this presentation we will discuss the many and varied cyber attacks that have recently occurred in the higher ed community. We will discuss the perpetrators, the victims, the impact and how these institutions have evolved to meet this threat. Mitigation techniques and defense strategies will be covered as will a discussion of effective security…

Simple mathematical law benchmarks human confrontations.

PubMed

Johnson, Neil F; Medina, Pablo; Zhao, Guannan; Messinger, Daniel S; Horgan, John; Gill, Paul; Bohorquez, Juan Camilo; Mattson, Whitney; Gangi, Devon; Qi, Hong; Manrique, Pedro; Velasquez, Nicolas; Morgenstern, Ana; Restrepo, Elvira; Johnson, Nicholas; Spagat, Michael; Zarama, Roberto

2013-12-10

Many high-profile societal problems involve an individual or group repeatedly attacking another - from child-parent disputes, sexual violence against women, civil unrest, violent conflicts and acts of terror, to current cyber-attacks on national infrastructure and ultrafast cyber-trades attacking stockholders. There is an urgent need to quantify the likely severity and timing of such future acts, shed light on likely perpetrators, and identify intervention strategies. Here we present a combined analysis of multiple datasets across all these domains which account for >100,000 events, and show that a simple mathematical law can benchmark them all. We derive this benchmark and interpret it, using a minimal mechanistic model grounded by state-of-the-art fieldwork. Our findings provide quantitative predictions concerning future attacks; a tool to help detect common perpetrators and abnormal behaviors; insight into the trajectory of a 'lone wolf'; identification of a critical threshold for spreading a message or idea among perpetrators; an intervention strategy to erode the most lethal clusters; and more broadly, a quantitative starting point for cross-disciplinary theorizing about human aggression at the individual and group level, in both real and online worlds.

Simple mathematical law benchmarks human confrontations

NASA Astrophysics Data System (ADS)

Johnson, Neil F.; Medina, Pablo; Zhao, Guannan; Messinger, Daniel S.; Horgan, John; Gill, Paul; Bohorquez, Juan Camilo; Mattson, Whitney; Gangi, Devon; Qi, Hong; Manrique, Pedro; Velasquez, Nicolas; Morgenstern, Ana; Restrepo, Elvira; Johnson, Nicholas; Spagat, Michael; Zarama, Roberto

2013-12-01

Many high-profile societal problems involve an individual or group repeatedly attacking another - from child-parent disputes, sexual violence against women, civil unrest, violent conflicts and acts of terror, to current cyber-attacks on national infrastructure and ultrafast cyber-trades attacking stockholders. There is an urgent need to quantify the likely severity and timing of such future acts, shed light on likely perpetrators, and identify intervention strategies. Here we present a combined analysis of multiple datasets across all these domains which account for >100,000 events, and show that a simple mathematical law can benchmark them all. We derive this benchmark and interpret it, using a minimal mechanistic model grounded by state-of-the-art fieldwork. Our findings provide quantitative predictions concerning future attacks; a tool to help detect common perpetrators and abnormal behaviors; insight into the trajectory of a `lone wolf' identification of a critical threshold for spreading a message or idea among perpetrators; an intervention strategy to erode the most lethal clusters; and more broadly, a quantitative starting point for cross-disciplinary theorizing about human aggression at the individual and group level, in both real and online worlds.

False Positive and False Negative Effects on Network Attacks

NASA Astrophysics Data System (ADS)

Shang, Yilun

2018-01-01

Robustness against attacks serves as evidence for complex network structures and failure mechanisms that lie behind them. Most often, due to detection capability limitation or good disguises, attacks on networks are subject to false positives and false negatives, meaning that functional nodes may be falsely regarded as compromised by the attacker and vice versa. In this work, we initiate a study of false positive/negative effects on network robustness against three fundamental types of attack strategies, namely, random attacks (RA), localized attacks (LA), and targeted attack (TA). By developing a general mathematical framework based upon the percolation model, we investigate analytically and by numerical simulations of attack robustness with false positive/negative rate (FPR/FNR) on three benchmark models including Erdős-Rényi (ER) networks, random regular (RR) networks, and scale-free (SF) networks. We show that ER networks are equivalently robust against RA and LA only when FPR equals zero or the initial network is intact. We find several interesting crossovers in RR and SF networks when FPR is taken into consideration. By defining the cost of attack, we observe diminishing marginal attack efficiency for RA, LA, and TA. Our finding highlights the potential risk of underestimating or ignoring FPR in understanding attack robustness. The results may provide insights into ways of enhancing robustness of network architecture and improve the level of protection of critical infrastructures.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haaland, C.M.; Wigner, E.P.

Given a number of short-range anti-ballistic missiles (ABM), one would like to distribute them among the possible targets in such a way as to minimize the fatalities which an attacker can cause. This mini-max problem is solved by an elementary mathematical method. There is an optimal distribution of the defending missiles which remains optimal independent of the size of the attack, provided the total number of defending missiles and the number of targets are reasonably large. Calculations for the U.S. indicate that the number of fatalities can be further reduced by a factor of 4 to 7 by means ofmore » passive defense, i.e., blast shelters, similar to those under Chinese cities.« less

Novel Psychological Formulation and Treatment of “Tic Attacks” in Tourette Syndrome

PubMed Central

Robinson, Sally; Hedderly, Tammy

2016-01-01

One important, but underreported, phenomenon in Tourette syndrome (TS) is the occurrence of “tic attacks.” These episodes have been described at conferences as sudden bouts of tics and/or functional tic-like movements, lasting from 15 min to several hours. They have also been described by patients in online TS communities. To date, there are no reports of tic attacks in the literature. The aim of this article is to stimulate discussion and inform clinical practices by describing the clinical presentation of 12 children (mean age 11 years and 3 months; SD = 2 years and 4 months) with TS and tic attacks, with a detailed case report for one case (13-year-old male). These children commonly present acutely to casualty departments and undergo unnecessary medical investigations. Interestingly, all children reported comorbid anxiety, with worries about the tics themselves and an increased internal focus of attention on tics once the attacks had started. In keeping with other children, the index case reported a strong internal focus of attention, with a relationship between physiological sensations/tic urges, worries about having tic attacks, and behavioral responses (e.g., body scanning, situational avoidance, and other responses). In our experience, the attacks reduce with psychological therapy, for example, the index case attended 13 sessions of therapy that included metacognitive and attention training techniques, as well as cognitive–behavioral strategies. Following treatment, an improvement was seen across a range of measures assessing tics, mood, anxiety, and quality of life. Thus, psychological techniques used to treat anxiety disorders are effective at supporting a reduction in tic attacks through modifying attention, worry processes, and negative beliefs. It is hypothesized that an attentional style of threat monitoring, difficulties tolerating internal sensory urges, cognitive misattributions, and maladaptive coping strategies contribute to the onset and maintenance of tic attacks. These cases provide support for the view that tic attacks are triggered and maintained by psychological factors, thereby challenging the view that tic attacks merely reflect extended bouts of tics. As such, we propose that the movements seen in tic attacks may resemble a combination of tics and functional neurological movements, with tic attacks reflecting episodes of panic and anxiety for individuals with TS. PMID:27242975

Weight Stigma Goes Viral on the Internet: Systematic Assessment of YouTube Comments Attacking Overweight Men and Women.

PubMed

Jeon, Yongwoog Andrew; Hale, Brent; Knackmuhs, Eric; Mackert, Michael

2018-03-20

Anonymous verbal attacks against overweight individuals on social media are common and widespread. These comments often use negative, misogynist, or derogatory words, which stigmatize the targeted individuals with obesity. These verbal attacks may cause depression in overweight individuals, which could subsequently promote unhealthy eating behavior (ie, binge eating) and further weight gain. To develop an intervention policy and strategies that tackle the anonymous, Web-based verbal attacks, a thorough understanding of the comments is necessary. This study aimed to examine how anonymous users verbally attack or defend overweight individuals in terms of 3 themes: (1) topic of verbal attack (ie, what aspects of overweight individuals are verbally attacked), (2) gender of commenters and targeted overweight individuals, and (3) intensity of derogation depending on the targeted gender (ie, the number of swear words used within comments). This study analyzed the content of YouTube comments that discuss overweight individuals or groups from 2 viral videos, titled "Fat Girl Tinder Date" and "Fat Guy Tinder Date." The twin videos provide an avenue through which to analyze discussions of obesity as they organically occurred in a contemporary setting. We randomly sampled and analyzed 320 comments based on a coding instrument developed for this study. First, there were twice as many comments verbally attacking overweight individuals (n=174) than comments defending them (n=89). Second, overweight women are attacked for their capacities (eg, laziness, maturity; 14/51, 28%), whereas overweight men are attacked for their heterosocial skills (eg, rudeness, annoyance; 24/29, 83%). Third, the majority of commenters who attacked overweight women are male (42/52, 81%). Fourth, attacking comments generated toward overweight women included more swear words (mean 0.44, SD 0.77) than those targeting men (mean 0.23, SD 0.48). Our data elucidate a worrying situation of frequent disinhibited aggressive messages against overweight individuals online. Importantly, the patterns of verbal aggression differ depending on the gender of the targeted overweight individuals. Thus, gender-tailored intervention strategies that specifically tackle Internet users' verbal aggression against overweight individuals need to be developed. ©Yongwoog Andrew Jeon, Brent Hale, Eric Knackmuhs, Michael Mackert. Originally published in the Interactive Journal of Medical Research (http://www.i-jmr.org/), 20.03.2018.

Attack Coverage in High-Level Men’s Volleyball: Organization on the Edge of Chaos?

PubMed Central

Laporta, Lorenzo; Nikolaidis, Pantelis; Thomas, Luke; Afonso, José

2015-01-01

Change is pervasive, but emerging patterns are occasionally detectable through analysis of systemic behaviors. Match analysis uses these patterns in order to reduce the degree of improvisation and to optimize the training process. However, it is possible that certain game phases elude systematic patterning. In this vein, our aim was to analyze the case of attack coverage in men’s volleyball, as we suspected it would elude systematic patterning and has received negligible attention in scientific research. We analyzed the occurrence of attack coverage in 4544 plays of the 2011 Volleyball World League. A Chi-square test with residual adjusted values was applied to explore significant associations between variables. A Monte Carlo correction was applied, as some cells had n<5. Effect sizes were determined using Cramer’s V. Overall, attack coverage occurred in 3.89% of ball possessions, and 23 distinct structures emerged. These structures lacked significant associations with the game complex, setting zone, and effect of attack coverage. Conversely, attack coverage structures showed significant associations with the attack zone and tempo, with very strong effect sizes (V=0.472 and V=0.521, respectively). As certain attack zones are deeply associated with attack tempo, it is apparent that quicker attack plays affect attack coverage structuring, promoting the formation of less complex structures. Ultimately, attack coverage structures seem to depend on momentary constraints, thereby rendering rigid systematization impracticable. Still, we contended that a principle-based approach might be suitable. This invites researchers to rethink how to interpret game regularities. PMID:26557208

Identification of Successive ``Unobservable'' Cyber Data Attacks in Power Systems Through Matrix Decomposition

NASA Astrophysics Data System (ADS)

Gao, Pengzhi; Wang, Meng; Chow, Joe H.; Ghiocel, Scott G.; Fardanesh, Bruce; Stefopoulos, George; Razanousky, Michael P.

2016-11-01

This paper presents a new framework of identifying a series of cyber data attacks on power system synchrophasor measurements. We focus on detecting "unobservable" cyber data attacks that cannot be detected by any existing method that purely relies on measurements received at one time instant. Leveraging the approximate low-rank property of phasor measurement unit (PMU) data, we formulate the identification problem of successive unobservable cyber attacks as a matrix decomposition problem of a low-rank matrix plus a transformed column-sparse matrix. We propose a convex-optimization-based method and provide its theoretical guarantee in the data identification. Numerical experiments on actual PMU data from the Central New York power system and synthetic data are conducted to verify the effectiveness of the proposed method.

Optimal design of studies of influenza transmission in households. I: case-ascertained studies.

PubMed

Klick, B; Leung, G M; Cowling, B J

2012-01-01

Case-ascertained household transmission studies, in which households including an 'index case' are recruited and followed up, are invaluable to understanding the epidemiology of influenza. We used a simulation approach parameterized with data from household transmission studies to evaluate alternative study designs. We compared studies that relied on self-reported illness in household contacts vs. studies that used home visits to collect swab specimens for virological confirmation of secondary infections, allowing for the trade-off between sample size vs. intensity of follow-up given a fixed budget. For studies estimating the secondary attack proportion, 2-3 follow-up visits with specimens collected from all members regardless of illness were optimal. However, for studies comparing secondary attack proportions between two or more groups, such as controlled intervention studies, designs with reactive home visits following illness reports in contacts were most powerful, while a design with one home visit optimally timed also performed well.

Conservation biology: lion attacks on humans in Tanzania.

PubMed

Packer, Craig; Ikanda, Dennis; Kissui, Bernard; Kushnir, Hadas

2005-08-18

Large carnivores inspire opposition to conservation efforts owing to their impact on livestock and human safety. Here we analyse the pattern of lion attacks over the past 15 years on humans in Tanzania, which has the largest population of lions in Africa, and find that they have killed more than 563 Tanzanians since 1990 and injured at least 308. Attacks have increased dramatically during this time: they peak at harvest time each year and are most frequent in areas with few prey apart from bush pigs (Potamochoerus larvatus), the most common nocturnal crop pest. Our findings provide an important starting point for devising strategies to reduce the risk to rural Tanzanians of lion attacks.

Intercept-Resend-Measure Attack Towards Quantum Private Comparison Protocol Using Genuine Four-Particle Entangled States and its Improvement

NASA Astrophysics Data System (ADS)

Pan, Hong-Ming

2018-03-01

Recently, Jia et al. proposed the quantum private comparison protocol with the genuine four-particle entangled states (Jia et al., Int. J. Theor. Phys. 51(4), 1187-1194 (2012)). Jia et al. claimed that in this protocol, TP cannot obtain Alice and Bob's secrets and only knows their comparison result. However, in this paper, we demonstrate that if TP is a genuine semi-honest third party, he can totally obtain Alice and Bob's secrets by launching a particular intercept-resend-measure attack. After suggesting the intercept-resend-measure attack strategy from TP first, we put forward one corresponding improvement to prevent this attack.

Using Machine Learning in Adversarial Environments.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Warren Leon Davis

Intrusion/anomaly detection systems are among the first lines of cyber defense. Commonly, they either use signatures or machine learning (ML) to identify threats, but fail to account for sophisticated attackers trying to circumvent them. We propose to embed machine learning within a game theoretic framework that performs adversarial modeling, develops methods for optimizing operational response based on ML, and integrates the resulting optimization codebase into the existing ML infrastructure developed by the Hybrid LDRD. Our approach addresses three key shortcomings of ML in adversarial settings: 1) resulting classifiers are typically deterministic and, therefore, easy to reverse engineer; 2) ML approachesmore » only address the prediction problem, but do not prescribe how one should operationalize predictions, nor account for operational costs and constraints; and 3) ML approaches do not model attackers’ response and can be circumvented by sophisticated adversaries. The principal novelty of our approach is to construct an optimization framework that blends ML, operational considerations, and a model predicting attackers reaction, with the goal of computing optimal moving target defense. One important challenge is to construct a realistic model of an adversary that is tractable, yet realistic. We aim to advance the science of attacker modeling by considering game-theoretic methods, and by engaging experimental subjects with red teaming experience in trying to actively circumvent an intrusion detection system, and learning a predictive model of such circumvention activities. In addition, we will generate metrics to test that a particular model of an adversary is consistent with available data.« less

A Novel Protective Framework for Defeating HTTP-Based Denial of Service and Distributed Denial of Service Attacks.

PubMed

Saleh, Mohammed A; Abdul Manaf, Azizah

2015-01-01

The growth of web technology has brought convenience to our life, since it has become the most important communication channel. However, now this merit is threatened by complicated network-based attacks, such as denial of service (DoS) and distributed denial of service (DDoS) attacks. Despite many researchers' efforts, no optimal solution that addresses all sorts of HTTP DoS/DDoS attacks is on offer. Therefore, this research aims to fix this gap by designing an alternative solution called a flexible, collaborative, multilayer, DDoS prevention framework (FCMDPF). The innovative design of the FCMDPF framework handles all aspects of HTTP-based DoS/DDoS attacks through the following three subsequent framework's schemes (layers). Firstly, an outer blocking (OB) scheme blocks attacking IP source if it is listed on the black list table. Secondly, the service traceback oriented architecture (STBOA) scheme is to validate whether the incoming request is launched by a human or by an automated tool. Then, it traces back the true attacking IP source. Thirdly, the flexible advanced entropy based (FAEB) scheme is to eliminate high rate DDoS (HR-DDoS) and flash crowd (FC) attacks. Compared to the previous researches, our framework's design provides an efficient protection for web applications against all sorts of DoS/DDoS attacks.

A Novel Protective Framework for Defeating HTTP-Based Denial of Service and Distributed Denial of Service Attacks

PubMed Central

Saleh, Mohammed A.; Abdul Manaf, Azizah

2015-01-01

The growth of web technology has brought convenience to our life, since it has become the most important communication channel. However, now this merit is threatened by complicated network-based attacks, such as denial of service (DoS) and distributed denial of service (DDoS) attacks. Despite many researchers' efforts, no optimal solution that addresses all sorts of HTTP DoS/DDoS attacks is on offer. Therefore, this research aims to fix this gap by designing an alternative solution called a flexible, collaborative, multilayer, DDoS prevention framework (FCMDPF). The innovative design of the FCMDPF framework handles all aspects of HTTP-based DoS/DDoS attacks through the following three subsequent framework's schemes (layers). Firstly, an outer blocking (OB) scheme blocks attacking IP source if it is listed on the black list table. Secondly, the service traceback oriented architecture (STBOA) scheme is to validate whether the incoming request is launched by a human or by an automated tool. Then, it traces back the true attacking IP source. Thirdly, the flexible advanced entropy based (FAEB) scheme is to eliminate high rate DDoS (HR-DDoS) and flash crowd (FC) attacks. Compared to the previous researches, our framework's design provides an efficient protection for web applications against all sorts of DoS/DDoS attacks. PMID:26065015

Defense of Cyber Infrastructures Against Cyber-Physical Attacks Using Game-Theoretic Models

DOE PAGES

Rao, Nageswara S. V.; Poole, Stephen W.; Ma, Chris Y. T.; ...

2015-04-06

The operation of cyber infrastructures relies on both cyber and physical components, which are subject to incidental and intentional degradations of different kinds. Within the context of network and computing infrastructures, we study the strategic interactions between an attacker and a defender using game-theoretic models that take into account both cyber and physical components. The attacker and defender optimize their individual utilities expressed as sums of cost and system terms. First, we consider a Boolean attack-defense model, wherein the cyber and physical sub-infrastructures may be attacked and reinforced as individual units. Second, we consider a component attack-defense model wherein theirmore » components may be attacked and defended, and the infrastructure requires minimum numbers of both to function. We show that the Nash equilibrium under uniform costs in both cases is computable in polynomial time, and it provides high-level deterministic conditions for the infrastructure survival. When probabilities of successful attack and defense, and of incidental failures are incorporated into the models, the results favor the attacker but otherwise remain qualitatively similar. This approach has been motivated and validated by our experiences with UltraScience Net infrastructure, which was built to support high-performance network experiments. In conclusion, the analytical results, however, are more general, and we apply them to simplified models of cloud and high-performance computing infrastructures.« less

Defense of Cyber Infrastructures Against Cyber-Physical Attacks Using Game-Theoretic Models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rao, Nageswara S. V.; Poole, Stephen W.; Ma, Chris Y. T.

The operation of cyber infrastructures relies on both cyber and physical components, which are subject to incidental and intentional degradations of different kinds. Within the context of network and computing infrastructures, we study the strategic interactions between an attacker and a defender using game-theoretic models that take into account both cyber and physical components. The attacker and defender optimize their individual utilities expressed as sums of cost and system terms. First, we consider a Boolean attack-defense model, wherein the cyber and physical sub-infrastructures may be attacked and reinforced as individual units. Second, we consider a component attack-defense model wherein theirmore » components may be attacked and defended, and the infrastructure requires minimum numbers of both to function. We show that the Nash equilibrium under uniform costs in both cases is computable in polynomial time, and it provides high-level deterministic conditions for the infrastructure survival. When probabilities of successful attack and defense, and of incidental failures are incorporated into the models, the results favor the attacker but otherwise remain qualitatively similar. This approach has been motivated and validated by our experiences with UltraScience Net infrastructure, which was built to support high-performance network experiments. In conclusion, the analytical results, however, are more general, and we apply them to simplified models of cloud and high-performance computing infrastructures.« less

Defense of Cyber Infrastructures Against Cyber-Physical Attacks Using Game-Theoretic Models.

PubMed

Rao, Nageswara S V; Poole, Stephen W; Ma, Chris Y T; He, Fei; Zhuang, Jun; Yau, David K Y

2016-04-01

The operation of cyber infrastructures relies on both cyber and physical components, which are subject to incidental and intentional degradations of different kinds. Within the context of network and computing infrastructures, we study the strategic interactions between an attacker and a defender using game-theoretic models that take into account both cyber and physical components. The attacker and defender optimize their individual utilities, expressed as sums of cost and system terms. First, we consider a Boolean attack-defense model, wherein the cyber and physical subinfrastructures may be attacked and reinforced as individual units. Second, we consider a component attack-defense model wherein their components may be attacked and defended, and the infrastructure requires minimum numbers of both to function. We show that the Nash equilibrium under uniform costs in both cases is computable in polynomial time, and it provides high-level deterministic conditions for the infrastructure survival. When probabilities of successful attack and defense, and of incidental failures, are incorporated into the models, the results favor the attacker but otherwise remain qualitatively similar. This approach has been motivated and validated by our experiences with UltraScience Net infrastructure, which was built to support high-performance network experiments. The analytical results, however, are more general, and we apply them to simplified models of cloud and high-performance computing infrastructures. © 2015 Society for Risk Analysis.

Conceptual model of acid attacks based on survivor's experiences: Lessons from a qualitative exploration.

PubMed

Sabzi Khoshnami, Mohammad; Mohammadi, Elham; Addelyan Rasi, Hamideh; Khankeh, Hamid Reza; Arshi, Maliheh

2017-05-01

Acid attack, a worldwide phenomenon, has been increasing in recent years. In addition to severe injuries to the face and body, such violence leads to psychological and social problems that affect the survivors' quality of life. The present study provides a more in-depth understanding of this phenomenon and explores the nature and dimensions of acid attacks based on survivors' experiences. A grounded theory study using semi-structured, recorded interviews and applying purposeful theoretical sampling was conducted with 12 acid attack survivors in Iran. Data were analysed using constant comparison in open, axial and selective coding stages. A conceptual model was developed to explain the relationships among the main categories extracted through the grounded theory study. Physical and psychological wounds emerged as a core category. Traditional context and extreme beauty value in society acted as the context of the physical and psychological wounds experienced. Living with a drug abuser with behavioural disorders and lack of problem-solving skills in interpersonal conflict were found to be causal conditions. Action strategies to deal with this experience were found to be composed of individual, interpersonal and structural levels. Education, percentage and place of burning acted as intervening conditions that influenced survivors' strategies. Finally, adverse consequences of social deprivation and feeling helpless and hindered were found to have an important impact. Acid attack lead to physical and psychological wounds in survivors. This is a multi-dimensional phenomenon involving illness, disability, and victimization, and requires a wide range of strategies at different levels. The conceptual model derived through this study can serve as a good basis for intervention programs. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

RISK DISCLOSURE AGAINST ATTACK ON CRITICAL INFRASTRUCTURES

NASA Astrophysics Data System (ADS)

Yoshida, Mamoru; Kobayashi, Kiyoshi

This paper analyzes the government's defensive and disclosure strategies to reduce the damage caused by terrorists that attack critical infrastructures using subjective game theory. The government recognizes a terrorist as a hidden opponent and the government's decision making about the policies against terror attacks depends on the belief about the existence of terrorist. In addition, it is not necessarily true that the government and the terrorist play the common game and make their decisions. Considering these points, the paper formulates the model in which the government and the terrorist formulate the subjective games respectively, and they induce the strategies using the equilibriums of their subjective games. The paper concluded that the government's disclosure about the implementation of the countermeasure, rather than the disclosure of warning level related with the belief about the existence of terrorist, brings about the higher increment of the subjective payoffs of the government.

Nuclear War Survival Skills

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kearny, C.H.

The purpose of this book is to provide Americans with information and instructions that will significantly increase their chances of surviving a possible nuclear attack. It brings together field-tested instructions that, if followed by a large fraction of Americans during a crisis that preceded an attack, could save millions of lives. The author is convinced that the vulnerability of our country to nuclear threat or attack must be reduced and that the wide dissemination of the information contained in this book would help achieve that objective of our overall defense strategy.

Allocation model for air tanker initial attack in firefighting

Treesearch

Francis E. Greulich; William G. O' Regan

1975-01-01

Timely and appropriate use of air tankers in firefighting can bring high returns, but their misuse can be expensive when measured in operating and other costs. An allocation model has been developed for identifying superior strategies-for air tanker initial attack, and for choosing an optimum set of allocations among airbases. Data are presented for a representative...

Parents' Emotion-Related Beliefs and Behaviours in Relation to Children's Coping with the 11 September 2001 Terrorist Attacks

ERIC Educational Resources Information Center

Halberstadt, Amy G.; Thompson, Julie A.; Parker, Alison E.; Dunsmore, Julie C.

2008-01-01

To assess relationships between parental socialization of emotion and children's coping following an intensely emotional event, parents' beliefs and behaviours regarding emotion and children's coping strategies were investigated after a set of terrorist attacks. Parents (n = 51) filled out the Parents' Beliefs about Negative Emotions questionnaire…

First-Strike Advantage: The United States’ Counter to China’s Preemptive Integrated Network Electronic Warfare Strategy

DTIC Science & Technology

2013-06-01

Ground: Chinese Capabilities for Computer Network Operations and Cyber Espionage,” 9. 57 Lolita C. Baldor, “Chinese Cyber Attacks On U.S. Continue...the Secretary of Defense, 2009. Baldor, Lolita C. “Chinese Cyber Attacks on U.S. Continue Totally Unabated, Leon Panetta.” Huffington Post (2012

Collective attacks and unconditional security in continuous variable quantum key distribution.

PubMed

Grosshans, Frédéric

2005-01-21

We present here an information theoretic study of Gaussian collective attacks on the continuous variable key distribution protocols based on Gaussian modulation of coherent states. These attacks, overlooked in previous security studies, give a finite advantage to the eavesdropper in the experimentally relevant lossy channel, but are not powerful enough to reduce the range of the reverse reconciliation protocols. Secret key rates are given for the ideal case where Bob performs optimal collective measurements, as well as for the realistic cases where he performs homodyne or heterodyne measurements. We also apply the generic security proof of Christiandl et al. to obtain unconditionally secure rates for these protocols.

Real-time monitoring of single-photon detectors against eavesdropping in quantum key distribution systems.

PubMed

da Silva, Thiago Ferreira; Xavier, Guilherme B; Temporão, Guilherme P; von der Weid, Jean Pierre

2012-08-13

By employing real-time monitoring of single-photon avalanche photodiodes we demonstrate how two types of practical eavesdropping strategies, the after-gate and time-shift attacks, may be detected. Both attacks are identified with the detectors operating without any special modifications, making this proposal well suited for real-world applications. The monitoring system is based on accumulating statistics of the times between consecutive detection events, and extracting the afterpulse and overall efficiency of the detectors in real-time using mathematical models fit to the measured data. We are able to directly observe changes in the afterpulse probabilities generated from the after-gate and faint after-gate attacks, as well as different timing signatures in the time-shift attack. We also discuss the applicability of our scheme to other general blinding attacks.

The 'Direct Attack' Strategy for Poverty Removal: Implementation Methodology.

ERIC Educational Resources Information Center

Sinha, Sanjay

1981-01-01

Discusses elements of an implementation methodology for the removal of poverty in India. Includes background, methodology, aggregation of demands, economics of the strategy, complementary activities and infrastructure, mechanics of implementation, and monitoring. (CT)

10th Annual Systems Engineering Conference: Volume 2 Wednesday

DTIC Science & Technology

2007-10-25

intelligently optimize resource performance. Self - Healing Detect hardware/software failures and reconfigure to permit continued operations. Self ...Types Wake Ice WEAPON/PLATFORM ACOUSTICS Self -Noise Radiated Noise Beam Forming Pulse Types Submarines, surface ships, and platform sensors P r o p P r o...Computing Self -Protecting Detect internal/external attacks and protect it’s resources from exploitation. Self -Optimizing Detect sub-optimal behaviors and

The robustness of multiplex networks under layer node-based attack

PubMed Central

Zhao, Da-wei; Wang, Lian-hai; Zhi, Yong-feng; Zhang, Jun; Wang, Zhen

2016-01-01

From transportation networks to complex infrastructures, and to social and economic networks, a large variety of systems can be described in terms of multiplex networks formed by a set of nodes interacting through different network layers. Network robustness, as one of the most successful application areas of complex networks, has attracted great interest in a myriad of research realms. In this regard, how multiplex networks respond to potential attack is still an open issue. Here we study the robustness of multiplex networks under layer node-based random or targeted attack, which means that nodes just suffer attacks in a given layer yet no additional influence to their connections beyond this layer. A theoretical analysis framework is proposed to calculate the critical threshold and the size of giant component of multiplex networks when nodes are removed randomly or intentionally. Via numerous simulations, it is unveiled that the theoretical method can accurately predict the threshold and the size of giant component, irrespective of attack strategies. Moreover, we also compare the robustness of multiplex networks under multiplex node-based attack and layer node-based attack, and find that layer node-based attack makes multiplex networks more vulnerable, regardless of average degree and underlying topology. PMID:27075870

The robustness of multiplex networks under layer node-based attack.

PubMed

Zhao, Da-wei; Wang, Lian-hai; Zhi, Yong-feng; Zhang, Jun; Wang, Zhen

2016-04-14

From transportation networks to complex infrastructures, and to social and economic networks, a large variety of systems can be described in terms of multiplex networks formed by a set of nodes interacting through different network layers. Network robustness, as one of the most successful application areas of complex networks, has attracted great interest in a myriad of research realms. In this regard, how multiplex networks respond to potential attack is still an open issue. Here we study the robustness of multiplex networks under layer node-based random or targeted attack, which means that nodes just suffer attacks in a given layer yet no additional influence to their connections beyond this layer. A theoretical analysis framework is proposed to calculate the critical threshold and the size of giant component of multiplex networks when nodes are removed randomly or intentionally. Via numerous simulations, it is unveiled that the theoretical method can accurately predict the threshold and the size of giant component, irrespective of attack strategies. Moreover, we also compare the robustness of multiplex networks under multiplex node-based attack and layer node-based attack, and find that layer node-based attack makes multiplex networks more vulnerable, regardless of average degree and underlying topology.

[Case of exploding head syndrome].

PubMed

Okura, Mutsumi; Taniguchi, Mitsutaka; Muraki, Hisae; Sugita, Hideko; Ohi, Motoharu

2010-01-01

Exploding head syndrome (EHS) attacks are characterized by the sensation of sudden loud banging noises, and are occasionally accompanied by the sensation of a flash light. Although these attacks in themselves are usually not painful, it is reported that EHS attacks may precede migraines and may be perceived as auras. A 53-year-old woman, with a 40-year history of fulgurating migraines, experienced 2 different types of EHS attacks. During most of the attacks, which were not painful, she heard sounds like someone yelling or cars passing by. Only 1 episode was accompanied with the sensation of a flash light and of sounds similar to those of an electrical short circuit. On the video-polysomnography, video-polysomnography showed 11 EHS attacks occurred during stage N1 and stage N2; these attacks were preceded by soft snoring. She also had moderate obstructive sleep apnea syndrome (Apnea Hypopnea Index: 16.7) for which an oral appliance was prescribed; the EHS attacks did not recur after this treatment. The pathophysiology of EHS is still unclear. A detailed analysis of PSG data may help in understanding the pathophysiology of this syndrome and also in the selection of therapeutic strategies.

Timing of cyber conflict

PubMed Central

Axelrod, Robert; Iliev, Rumen

2014-01-01

Nations are accumulating cyber resources in the form of stockpiles of zero-day exploits as well as other novel methods of engaging in future cyber conflict against selected targets. This paper analyzes the optimal timing for the use of such cyber resources. A simple mathematical model is offered to clarify how the timing of such a choice can depend on the stakes involved in the present situation, as well as the characteristics of the resource for exploitation. The model deals with the question of when the resource should be used given that its use today may well prevent it from being available for use later. The analysis provides concepts, theory, applications, and distinctions to promote the understanding strategy aspects of cyber conflict. Case studies include the Stuxnet attack on Iran’s nuclear program, the Iranian cyber attack on the energy firm Saudi Aramco, the persistent cyber espionage carried out by the Chinese military, and an analogous case of economic coercion by China in a dispute with Japan. The effects of the rapidly expanding market for zero-day exploits are also analyzed. The goal of the paper is to promote the understanding of this domain of cyber conflict to mitigate the harm it can do, and harness the capabilities it can provide. PMID:24474752

Reactance and Coping Responses to Tobacco Counter-Advertisements.

PubMed

Wehbe, Michelle S; Basil, Michael; Basil, Debra

2017-07-01

Tobacco prevention messages generally take one of three tactics: They can be educational, attack the tobacco industry, or attack particular brands. Being a smoker and smoking a particular brand may form an essential part of a person's self-identity. As such, reactance theory suggests that attack messages can unintentionally attack smokers' self-image. A 2 × 2 × 2 × 2 experiment using six different messages and 260 respondents tested whether smokers have different reactions to tobacco counter-advertisements than nonsmokers. It also examined whether attacking a smoker's brand leads to greater reactance and other maladaptive responses compared to attacking other brands. Consistent with predictions, smokers reported more maladaptive coping responses and fewer adaptive coping responses to tobacco counter-ads than nonsmokers. The study also reveals differences attributable to brand identification. These findings suggest that interventions should consider different counter-advertising tactics for smokers and nonsmokers. Similar admonitions may apply to counter-advertising strategies on other health issues.

SCA security verification on wireless sensor network node

NASA Astrophysics Data System (ADS)

He, Wei; Pizarro, Carlos; de la Torre, Eduardo; Portilla, Jorge; Riesgo, Teresa

2011-05-01

Side Channel Attack (SCA) differs from traditional mathematic attacks. It gets around of the exhaustive mathematic calculation and precisely pin to certain points in the cryptographic algorithm to reveal confidential information from the running crypto-devices. Since the introduction of SCA by Paul Kocher et al [1], it has been considered to be one of the most critical threats to the resource restricted but security demanding applications, such as wireless sensor networks. In this paper, we focus our work on the SCA-concerned security verification on WSN (wireless sensor network). A detailed setup of the platform and an analysis of the results of DPA (power attack) and EMA (electromagnetic attack) is presented. The setup follows the way of low-cost setup to make effective SCAs. Meanwhile, surveying the weaknesses of WSNs in resisting SCA attacks, especially for the EM attack. Finally, SCA-Prevention suggestions based on Differential Security Strategy for the FPGA hardware implementation in WSN will be given, helping to get an improved compromise between security and cost.

Device-independent security of quantum cryptography against collective attacks.

PubMed

Acín, Antonio; Brunner, Nicolas; Gisin, Nicolas; Massar, Serge; Pironio, Stefano; Scarani, Valerio

2007-06-08

We present the optimal collective attack on a quantum key distribution protocol in the "device-independent" security scenario, where no assumptions are made about the way the quantum key distribution devices work or on what quantum system they operate. Our main result is a tight bound on the Holevo information between one of the authorized parties and the eavesdropper, as a function of the amount of violation of a Bell-type inequality.

Bypass Ratio: The US Air Force and Light-Attack Aviation

DTIC Science & Technology

2013-06-01

for making recommendations which optimize base activity and its impact on the environment. Local and state politics can keep a base open even if it is...for the region, and this conduct can affect global commerce. Such disruption and destabilization in turn can have large impacts on the US diplomatic... IFR ) operations, emergency procedures, low-level flight and two-ship formation flight by this stage. Once track selection occurs, the light-attack

Deep Learning Method for Denial of Service Attack Detection Based on Restricted Boltzmann Machine.

PubMed

Imamverdiyev, Yadigar; Abdullayeva, Fargana

2018-06-01

In this article, the application of the deep learning method based on Gaussian-Bernoulli type restricted Boltzmann machine (RBM) to the detection of denial of service (DoS) attacks is considered. To increase the DoS attack detection accuracy, seven additional layers are added between the visible and the hidden layers of the RBM. Accurate results in DoS attack detection are obtained by optimization of the hyperparameters of the proposed deep RBM model. The form of the RBM that allows application of the continuous data is used. In this type of RBM, the probability distribution of the visible layer is replaced by a Gaussian distribution. Comparative analysis of the accuracy of the proposed method with Bernoulli-Bernoulli RBM, Gaussian-Bernoulli RBM, deep belief network type deep learning methods on DoS attack detection is provided. Detection accuracy of the methods is verified on the NSL-KDD data set. Higher accuracy from the proposed multilayer deep Gaussian-Bernoulli type RBM is obtained.

Jamming Attack in Wireless Sensor Network: From Time to Space

NASA Astrophysics Data System (ADS)

Sun, Yanqiang; Wang, Xiaodong; Zhou, Xingming

Classical jamming attack models in the time domain have been proposed, such as constant jammer, random jammer, and reactive jammer. In this letter, we consider a new problem: given k jammers, how does the attacker minimize the pair-wise connectivity among the nodes in a Wireless Sensor Network (WSN)? We call this problem k-Jammer Deployment Problem (k-JDP). To the best of our knowledge, this is the first attempt at considering the position-critical jamming attack against wireless sensor network. We mainly make three contributions. First, we prove that the decision version of k-JDP is NP-complete even in the ideal situation where the attacker has full knowledge of the topology information of sensor network. Second, we propose a mathematical formulation based on Integer Programming (IP) model which yields an optimal solution. Third, we present a heuristic algorithm HAJDP, and compare it with the IP model. Numerical results show that our heuristic algorithm is computationally efficient.

Defense Strategies for Asymmetric Networked Systems with Discrete Components.

PubMed

Rao, Nageswara S V; Ma, Chris Y T; Hausken, Kjell; He, Fei; Yau, David K Y; Zhuang, Jun

2018-05-03

We consider infrastructures consisting of a network of systems, each composed of discrete components. The network provides the vital connectivity between the systems and hence plays a critical, asymmetric role in the infrastructure operations. The individual components of the systems can be attacked by cyber and physical means and can be appropriately reinforced to withstand these attacks. We formulate the problem of ensuring the infrastructure performance as a game between an attacker and a provider, who choose the numbers of the components of the systems and network to attack and reinforce, respectively. The costs and benefits of attacks and reinforcements are characterized using the sum-form, product-form and composite utility functions, each composed of a survival probability term and a component cost term. We present a two-level characterization of the correlations within the infrastructure: (i) the aggregate failure correlation function specifies the infrastructure failure probability given the failure of an individual system or network, and (ii) the survival probabilities of the systems and network satisfy first-order differential conditions that capture the component-level correlations using multiplier functions. We derive Nash equilibrium conditions that provide expressions for individual system survival probabilities and also the expected infrastructure capacity specified by the total number of operational components. We apply these results to derive and analyze defense strategies for distributed cloud computing infrastructures using cyber-physical models.

Defense Strategies for Asymmetric Networked Systems with Discrete Components

PubMed Central

Rao, Nageswara S. V.; Ma, Chris Y. T.; Hausken, Kjell; He, Fei; Yau, David K. Y.

2018-01-01

We consider infrastructures consisting of a network of systems, each composed of discrete components. The network provides the vital connectivity between the systems and hence plays a critical, asymmetric role in the infrastructure operations. The individual components of the systems can be attacked by cyber and physical means and can be appropriately reinforced to withstand these attacks. We formulate the problem of ensuring the infrastructure performance as a game between an attacker and a provider, who choose the numbers of the components of the systems and network to attack and reinforce, respectively. The costs and benefits of attacks and reinforcements are characterized using the sum-form, product-form and composite utility functions, each composed of a survival probability term and a component cost term. We present a two-level characterization of the correlations within the infrastructure: (i) the aggregate failure correlation function specifies the infrastructure failure probability given the failure of an individual system or network, and (ii) the survival probabilities of the systems and network satisfy first-order differential conditions that capture the component-level correlations using multiplier functions. We derive Nash equilibrium conditions that provide expressions for individual system survival probabilities and also the expected infrastructure capacity specified by the total number of operational components. We apply these results to derive and analyze defense strategies for distributed cloud computing infrastructures using cyber-physical models. PMID:29751588

Application of variable-gain output feedback for high-alpha control

NASA Technical Reports Server (NTRS)

Ostroff, Aaron J.

1990-01-01

A variable-gain, optimal, discrete, output feedback design approach that is applied to a nonlinear flight regime is described. The flight regime covers a wide angle-of-attack range that includes stall and post stall. The paper includes brief descriptions of the variable-gain formulation, the discrete-control structure and flight equations used to apply the design approach, and the high performance airplane model used in the application. Both linear and nonlinear analysis are shown for a longitudinal four-model design case with angles of attack of 5, 15, 35, and 60 deg. Linear and nonlinear simulations are compared for a single-point longitudinal design at 60 deg angle of attack. Nonlinear simulations for the four-model, multi-mode, variable-gain design include a longitudinal pitch-up and pitch-down maneuver and high angle-of-attack regulation during a lateral maneuver.

Relevance of terrorism for Italian students not directly exposed to it: The affective impact of the 2015 Paris and the 2016 Brussels attacks.

PubMed

Raccanello, Daniela; Burro, Roberto; Brondino, Margherita; Pasini, Margherita

2018-04-01

Notwithstanding the dramatically increasing frequency of acts of terrorism in Europe and the extent of their media coverage, there is lack of knowledge on people's affective reactions and associated emotion regulation strategies. We explored the affective impact on two cohorts of Italian students (n = 193) possibly exposed vicariously through the mass media to the 2015 Paris or the 2016 Brussels terrorist attacks, respectively. We accessed data from three online questionnaires: one on emotion regulation administered before each attack; one on daily affect administered just before and after each attack; and one on causes of weekly affect and life satisfaction administered at the end of the week in which each attack occurred. The attacks were perceived as relevant for influencing negative affect for 22% of the students. For them, suppression-less frequently used than reappraisal-was associated with an improvement of affect after each attack but negatively related to life satisfaction concerning the week in which the attacks occurred. Our data showed that the recent terrorist attacks occurring in Europe had an affective impact on people at some distance who were vicariously exposed and point to the protective role of emotion regulation as a key resource for individuals' well-being. Copyright © 2017 John Wiley & Sons, Ltd.

An Optimal Method for Detecting Internal and External Intrusion in MANET

NASA Astrophysics Data System (ADS)

Rafsanjani, Marjan Kuchaki; Aliahmadipour, Laya; Javidi, Mohammad M.

Mobile Ad hoc Network (MANET) is formed by a set of mobile hosts which communicate among themselves through radio waves. The hosts establish infrastructure and cooperate to forward data in a multi-hop fashion without a central administration. Due to their communication type and resources constraint, MANETs are vulnerable to diverse types of attacks and intrusions. In this paper, we proposed a method for prevention internal intruder and detection external intruder by using game theory in mobile ad hoc network. One optimal solution for reducing the resource consumption of detection external intruder is to elect a leader for each cluster to provide intrusion service to other nodes in the its cluster, we call this mode moderate mode. Moderate mode is only suitable when the probability of attack is low. Once the probability of attack is high, victim nodes should launch their own IDS to detect and thwart intrusions and we call robust mode. In this paper leader should not be malicious or selfish node and must detect external intrusion in its cluster with minimum cost. Our proposed method has three steps: the first step building trust relationship between nodes and estimation trust value for each node to prevent internal intrusion. In the second step we propose an optimal method for leader election by using trust value; and in the third step, finding the threshold value for notifying the victim node to launch its IDS once the probability of attack exceeds that value. In first and third step we apply Bayesian game theory. Our method due to using game theory, trust value and honest leader can effectively improve the network security, performance and reduce resource consumption.

Long-Term Preservation of Left Ventricular Systolic Function in Patients With Refractory Angina Pectoris and Inducible Myocardial Ischemia on Optimal Medical Therapy.

PubMed

Slavich, Massimo; Maranta, Francesco; Fumero, Andrea; Godino, Cosmo; Giannini, Francesco; Oppizzi, Michele; Colombo, Antonio; Fragasso, Gabriele; Margonato, Alberto

2016-05-15

Refractory angina pectoris (RAP) represents a clinical condition characterized by frequent episodes of chest pain despite therapy optimization. According to myocardial stunning and myocardial hibernation definitions, RAP should represent the ideal condition for systolic dysfunction development. We aim to investigate the evolution of left ventricular (LV) function in patients with RAP. A retrospective study which encompasses 144 patients with RAP referred to our institution from 1999 to December 2014 was performed. Of them, 88 met the inclusion criteria, and LV function was assessed by echocardiography. All of them had persistent angina episodes on top of optimal medical therapy and evidence of significant inducible myocardial ischemia and no further revascularization options. Nitrates consumption rate, time of angina duration, and the number of angina attacks were evaluated. In the whole population, ejection fraction (EF) was 44% ± 2. EF was significantly lower in patients with previous myocardial infarction (41% ± 1.5 vs 51% ± 1.8, p <0.0001). The duration time and the number of angina attacks did not correlate with EF in the whole population and in patients without previous myocardial infarction. In patients with previous myocardial infarction, the number of anginal attacks did not correlate with EF, but EF appeared higher in patients with angina duration >5 years (<5 years EF 37% ± 1 [n = 26]; >5 years 44% ± 2 [n = 44]; p 0.02). Long-term LV function in patients with RAP is generally preserved. A previous history of myocardial infarction is the only determinant in the development of systolic dysfunction. In conclusion, frequent angina attacks and a long-term history of angina are not apparently associated to worse LV function. Copyright © 2016 Elsevier Inc. All rights reserved.

Topological Vulnerability Analysis

NASA Astrophysics Data System (ADS)

Jajodia, Sushil; Noel, Steven

Traditionally, network administrators rely on labor-intensive processes for tracking network configurations and vulnerabilities. This requires a great deal of expertise, and is error prone because of the complexity of networks and associated security data. The interdependencies of network vulnerabilities make traditional point-wise vulnerability analysis inadequate. We describe a Topological Vulnerability Analysis (TVA) approach that analyzes vulnerability dependencies and shows all possible attack paths into a network. From models of the network vulnerabilities and potential attacker exploits, we compute attack graphs that convey the impact of individual and combined vulnerabilities on overall security. TVA finds potential paths of vulnerability through a network, showing exactly how attackers may penetrate a network. From this, we identify key vulnerabilities and provide strategies for protection of critical network assets.

Securing Cyberspace: Approaches to Developing an Effective Cyber-Security Strategy

DTIC Science & Technology

2011-05-15

attackers, cyber - criminals or even teenage hackers. Protecting cyberspace is a national security priority. President Obama’s National Security...prefers to engage international law enforcement to investigate and catch cyber criminals .40 International cooperation could resolve jurisdictional...sheltered them. Similarly, a state that fails to prosecute cyber - criminals , or who gives safe haven to individuals or groups that conduct cyber-attacks

Adaptive and Defensive Strategies in Post-Traumatic Play of Young Children Exposed to Violent Attacks

ERIC Educational Resources Information Center

Chazan, Saralea; Cohen, Esther

2010-01-01

Twenty-three children, aged four to eight years, who had been exposed to violent attacks, were videotaped in individual 40-minute play sessions. These play narratives were recorded by a student researcher trained in narrative analysis and play therapy. She then sorted these play vignettes into three patterns of post-traumatic play, defined in the…

Aircrew Training Devices: Fidelity Features.

DTIC Science & Technology

1981-01-01

providing artificial cues for glideslope and lineup . He found that an adaptive strategy for using augmenting cues, where the presence or absence of the...with continuously available sources of augmented information for lineup and glideslope in the simulatot, they performed more poorly on test trials...flown: fighting wing, barrel roll attack, sequential attack, free engagement, aileron roll and loop. Results indicated higher ratings of realism for

Metasystox-R, applied in Mauget injectors, ineffective in protecting individual ponderosa pines from western pine beetles

Treesearch

Michael I. Haverty; Patrick J. Shea; John M. Wenz

1996-01-01

The effectiveness of registered application rates of the insecticide metasystox-R applied with Mauget tree injectors (INJECT-A-CIDE) was assessed in two strategies: (1) treatment of trees before western pine beetle attack (preventive treatment), and (2) treatment of trees after attack by western pine beetle (remedial treatment) for protection of individual, high-value...

Simple mathematical law benchmarks human confrontations

PubMed Central

Johnson, Neil F.; Medina, Pablo; Zhao, Guannan; Messinger, Daniel S.; Horgan, John; Gill, Paul; Bohorquez, Juan Camilo; Mattson, Whitney; Gangi, Devon; Qi, Hong; Manrique, Pedro; Velasquez, Nicolas; Morgenstern, Ana; Restrepo, Elvira; Johnson, Nicholas; Spagat, Michael; Zarama, Roberto

2013-01-01

Many high-profile societal problems involve an individual or group repeatedly attacking another – from child-parent disputes, sexual violence against women, civil unrest, violent conflicts and acts of terror, to current cyber-attacks on national infrastructure and ultrafast cyber-trades attacking stockholders. There is an urgent need to quantify the likely severity and timing of such future acts, shed light on likely perpetrators, and identify intervention strategies. Here we present a combined analysis of multiple datasets across all these domains which account for >100,000 events, and show that a simple mathematical law can benchmark them all. We derive this benchmark and interpret it, using a minimal mechanistic model grounded by state-of-the-art fieldwork. Our findings provide quantitative predictions concerning future attacks; a tool to help detect common perpetrators and abnormal behaviors; insight into the trajectory of a ‘lone wolf'; identification of a critical threshold for spreading a message or idea among perpetrators; an intervention strategy to erode the most lethal clusters; and more broadly, a quantitative starting point for cross-disciplinary theorizing about human aggression at the individual and group level, in both real and online worlds. PMID:24322528

Various chemical strategies to deceive ants in three Arhopala species (lepidoptera: Lycaenidae) exploiting Macaranga myrmecophytes.

PubMed

Inui, Yoko; Shimizu-Kaya, Usun; Okubo, Tadahiro; Yamsaki, Eri; Itioka, Takao

2015-01-01

Macaranga myrmecophytes (ant-plants) are generally well protected from herbivore attacks by their symbiotic ants (plant-ants). However, larvae of Arhopala (Lepidoptera: Lycaenidae) species survive and develop on specific Macaranga ant-plant species without being attacked by the plant-ants of their host species. We hypothesized that Arhopala larvae chemically mimic or camouflage themselves with the ants on their host plant so that the larvae are accepted by the plant-ant species of their host. Chemical analyses of cuticular hydrocarbons showed that chemical congruency varied among Arhopala species; A. dajagaka matched well the host plant-ants, A. amphimuta did not match, and unexpectedly, A. zylda lacked hydrocarbons. Behaviorally, the larvae and dummies coated with cuticular chemicals of A. dajagaka were well attended by the plant-ants, especially by those of the host. A. amphimuta was often attacked by all plant-ants except for the host plant-ants toward the larvae, and those of A. zylda were ignored by all plant-ants. Our results suggested that conspicuous variations exist in the chemical strategies used by the myrmecophilous butterflies that allow them to avoid ant attack and be accepted by the plant-ant colonies.

Various Chemical Strategies to Deceive Ants in Three Arhopala Species (Lepidoptera: Lycaenidae) Exploiting Macaranga Myrmecophytes

PubMed Central

Inui, Yoko; Shimizu-kaya, Usun; Okubo, Tadahiro; Yamsaki, Eri; Itioka, Takao

2015-01-01

Macaranga myrmecophytes (ant-plants) are generally well protected from herbivore attacks by their symbiotic ants (plant-ants). However, larvae of Arhopala (Lepidoptera: Lycaenidae) species survive and develop on specific Macaranga ant-plant species without being attacked by the plant-ants of their host species. We hypothesized that Arhopala larvae chemically mimic or camouflage themselves with the ants on their host plant so that the larvae are accepted by the plant-ant species of their host. Chemical analyses of cuticular hydrocarbons showed that chemical congruency varied among Arhopala species; A. dajagaka matched well the host plant-ants, A. amphimuta did not match, and unexpectedly, A. zylda lacked hydrocarbons. Behaviorally, the larvae and dummies coated with cuticular chemicals of A. dajagaka were well attended by the plant-ants, especially by those of the host. A. amphimuta was often attacked by all plant-ants except for the host plant-ants toward the larvae, and those of A. zylda were ignored by all plant-ants. Our results suggested that conspicuous variations exist in the chemical strategies used by the myrmecophilous butterflies that allow them to avoid ant attack and be accepted by the plant-ant colonies. PMID:25853675

An Optimal Algorithm towards Successive Location Privacy in Sensor Networks with Dynamic Programming

NASA Astrophysics Data System (ADS)

Zhao, Baokang; Wang, Dan; Shao, Zili; Cao, Jiannong; Chan, Keith C. C.; Su, Jinshu

In wireless sensor networks, preserving location privacy under successive inference attacks is extremely critical. Although this problem is NP-complete in general cases, we propose a dynamic programming based algorithm and prove it is optimal in special cases where the correlation only exists between p immediate adjacent observations.

Enhancing robustness of interdependent network by adding connectivity and dependence links

NASA Astrophysics Data System (ADS)

Cui, Pengshuai; Zhu, Peidong; Wang, Ke; Xun, Peng; Xia, Zhuoqun

2018-05-01

Enhancing robustness of interdependent networks by adding connectivity links has been researched extensively, however, few of them are focusing on adding both connectivity and dependence links to enhance robustness. In this paper, we aim to study how to allocate the limited costs reasonably to add both connectivity and dependence links. Firstly, we divide the attackers into stubborn attackers and smart attackers according to whether would they change their attack modes with the changing of network structure; Then by simulations, link addition strategies are given separately according to different attackers, with which we can allocate the limited costs to add connectivity links and dependence links reasonably and achieve more robustness than only adding connectivity links or dependence links. The results show that compared to only adding connectivity links or dependence links, allocating the limited resources reasonably and adding both connectivity links and dependence links could bring more robustness to the interdependent networks.

Recovery of infrastructure networks after localised attacks.

PubMed

Hu, Fuyu; Yeung, Chi Ho; Yang, Saini; Wang, Weiping; Zeng, An

2016-04-14

The stability of infrastructure network is always a critical issue studied by researchers in different fields. A lot of works have been devoted to reveal the robustness of the infrastructure networks against random and malicious attacks. However, real attack scenarios such as earthquakes and typhoons are instead localised attacks which are investigated only recently. Unlike previous studies, we examine in this paper the resilience of infrastructure networks by focusing on the recovery process from localised attacks. We introduce various preferential repair strategies and found that they facilitate and improve network recovery compared to that of random repairs, especially when population size is uneven at different locations. Moreover, our strategic repair methods show similar effectiveness as the greedy repair. The validations are conducted on simulated networks, and on real networks with real disasters. Our method is meaningful in practice as it can largely enhance network resilience and contribute to network risk reduction.

Recovery of infrastructure networks after localised attacks

PubMed Central

Hu, Fuyu; Yeung, Chi Ho; Yang, Saini; Wang, Weiping; Zeng, An

2016-01-01

The stability of infrastructure network is always a critical issue studied by researchers in different fields. A lot of works have been devoted to reveal the robustness of the infrastructure networks against random and malicious attacks. However, real attack scenarios such as earthquakes and typhoons are instead localised attacks which are investigated only recently. Unlike previous studies, we examine in this paper the resilience of infrastructure networks by focusing on the recovery process from localised attacks. We introduce various preferential repair strategies and found that they facilitate and improve network recovery compared to that of random repairs, especially when population size is uneven at different locations. Moreover, our strategic repair methods show similar effectiveness as the greedy repair. The validations are conducted on simulated networks, and on real networks with real disasters. Our method is meaningful in practice as it can largely enhance network resilience and contribute to network risk reduction. PMID:27075559

Potential use of advanced process control for safety purposes during attack of a process plant.

PubMed

Whiteley, James R

2006-03-17

Many refineries and commodity chemical plants employ advanced process control (APC) systems to improve throughputs and yields. These APC systems utilize empirical process models for control purposes and enable operation closer to constraints than can be achieved with traditional PID regulatory feedback control. Substantial economic benefits are typically realized from the addition of APC systems. This paper considers leveraging the control capabilities of existing APC systems to minimize the potential impact of a terrorist attack on a process plant (e.g., petroleum refinery). Two potential uses of APC are described. The first is a conventional application of APC and involves automatically moving the process to a reduced operating rate when an attack first begins. The second is a non-conventional application and involves reconfiguring the APC system to optimize safety rather than economics. The underlying intent in both cases is to reduce the demands on the operator to allow focus on situation assessment and optimal response planning. An overview of APC is provided along with a brief description of the modifications required for the proposed new applications of the technology.

Reactive strategies for containing developing outbreaks of pandemic influenza

PubMed Central

2011-01-01

Background In 2009 and the early part of 2010, the northern hemisphere had to cope with the first waves of the new influenza A (H1N1) pandemic. Despite high-profile vaccination campaigns in many countries, delays in administration of vaccination programs were common, and high vaccination coverage levels were not achieved. This experience suggests the need to explore the epidemiological and economic effectiveness of additional, reactive strategies for combating pandemic influenza. Methods We use a stochastic model of pandemic influenza to investigate realistic strategies that can be used in reaction to developing outbreaks. The model is calibrated to documented illness attack rates and basic reproductive number (R0) estimates, and constructed to represent a typical mid-sized North American city. Results Our model predicts an average illness attack rate of 34.1% in the absence of intervention, with total costs associated with morbidity and mortality of US$81 million for such a city. Attack rates and economic costs can be reduced to 5.4% and US$37 million, respectively, when low-coverage reactive vaccination and limited antiviral use are combined with practical, minimally disruptive social distancing strategies, including short-term, as-needed closure of individual schools, even when vaccine supply-chain-related delays occur. Results improve with increasing vaccination coverage and higher vaccine efficacy. Conclusions Such combination strategies can be substantially more effective than vaccination alone from epidemiological and economic standpoints, and warrant strong consideration by public health authorities when reacting to future outbreaks of pandemic influenza. PMID:21356128

ON THE PROBLEM OF CORRECTING TWISTED TURBINE BLADES,

DTIC Science & Technology

TURBINE BLADES , DESIGN), GAS TURBINES , STEAM TURBINES , BLADE AIRFOILS , ASPECT RATIO, FLUID DYNAMICS, SECONDARY FLOW, ANGLE OF ATTACK, INLET GUIDE VANES , CORRECTIONS, PERFORMANCE( ENGINEERING ), OPTIMIZATION, USSR

Towards Reliable Evaluation of Anomaly-Based Intrusion Detection Performance

NASA Technical Reports Server (NTRS)

Viswanathan, Arun

2012-01-01

This report describes the results of research into the effects of environment-induced noise on the evaluation process for anomaly detectors in the cyber security domain. This research was conducted during a 10-week summer internship program from the 19th of August, 2012 to the 23rd of August, 2012 at the Jet Propulsion Laboratory in Pasadena, California. The research performed lies within the larger context of the Los Angeles Department of Water and Power (LADWP) Smart Grid cyber security project, a Department of Energy (DoE) funded effort involving the Jet Propulsion Laboratory, California Institute of Technology and the University of Southern California/ Information Sciences Institute. The results of the present effort constitute an important contribution towards building more rigorous evaluation paradigms for anomaly-based intrusion detectors in complex cyber physical systems such as the Smart Grid. Anomaly detection is a key strategy for cyber intrusion detection and operates by identifying deviations from profiles of nominal behavior and are thus conceptually appealing for detecting "novel" attacks. Evaluating the performance of such a detector requires assessing: (a) how well it captures the model of nominal behavior, and (b) how well it detects attacks (deviations from normality). Current evaluation methods produce results that give insufficient insight into the operation of a detector, inevitably resulting in a significantly poor characterization of a detectors performance. In this work, we first describe a preliminary taxonomy of key evaluation constructs that are necessary for establishing rigor in the evaluation regime of an anomaly detector. We then focus on clarifying the impact of the operational environment on the manifestation of attacks in monitored data. We show how dynamic and evolving environments can introduce high variability into the data stream perturbing detector performance. Prior research has focused on understanding the impact of this variability in training data for anomaly detectors, but has ignored variability in the attack signal that will necessarily affect the evaluation results for such detectors. We posit that current evaluation strategies implicitly assume that attacks always manifest in a stable manner; we show that this assumption is wrong. We describe a simple experiment to demonstrate the effects of environmental noise on the manifestation of attacks in data and introduce the notion of attack manifestation stability. Finally, we argue that conclusions about detector performance will be unreliable and incomplete if the stability of attack manifestation is not accounted for in the evaluation strategy.

Deterrence and Risk Preferences in Sequential Attacker-Defender Games with Continuous Efforts.

PubMed

Payyappalli, Vineet M; Zhuang, Jun; Jose, Victor Richmond R

2017-11-01

Most attacker-defender games consider players as risk neutral, whereas in reality attackers and defenders may be risk seeking or risk averse. This article studies the impact of players' risk preferences on their equilibrium behavior and its effect on the notion of deterrence. In particular, we study the effects of risk preferences in a single-period, sequential game where a defender has a continuous range of investment levels that could be strategically chosen to potentially deter an attack. This article presents analytic results related to the effect of attacker and defender risk preferences on the optimal defense effort level and their impact on the deterrence level. Numerical illustrations and some discussion of the effect of risk preferences on deterrence and the utility of using such a model are provided, as well as sensitivity analysis of continuous attack investment levels and uncertainty in the defender's beliefs about the attacker's risk preference. A key contribution of this article is the identification of specific scenarios in which the defender using a model that takes into account risk preferences would be better off than a defender using a traditional risk-neutral model. This study provides insights that could be used by policy analysts and decisionmakers involved in investment decisions in security and safety. © 2017 Society for Risk Analysis.

The Tonya Harding Controversy: An Analysis of Image Restoration Strategies.

ERIC Educational Resources Information Center

Benoit, William L.; Hanczor, Robert S.

1994-01-01

Analyzes Tonya Harding's defense of her image in "Eye to Eye with Connie Chung," applying the theory of image restoration discourse. Finds that the principal strategies employed in her behalf were bolstering, denial, and attacking her accuser, but that these strategies were not developed very effectively in this instance. (SR)

Flight-management strategies for escape from microburst encounters. M.S. Thesis - George Washington Univ.

NASA Technical Reports Server (NTRS)

Hinton, David A.

1988-01-01

An effort is underway by NASA, FAA, and industry to reduce the threat of convective microburst wind shear phenomena to aircraft. The goal is to develop and test a candidate set of strategies for recovery from inadvertent microburst encounters during takeoff. Candidate strategies were developed and evaluated using a fast-time simulation consisting of a simple point-mass performance model of a transport-category airplane and an analytical microburst model. The results indicate that the recovery strategy characteristics that best utilize available airplane energy include an initial reduction in pitch attitude to reduce the climb rate, followed by an increase in pitch up to the stick shaker angle of attack. The stick shaker angle of attack should be reached just as the airplane is exiting the microburst. The shallowest angle of climb necessary for obstacle clearance should be used. If the altitude is higher than necessary, an intentional descent to reduce the airspeed deceleration should be used. Of the strategies tested, two flight-path-angle based strategies had the highest recovery altitudes and the least sensitivity to variations in the encounter scenarios.

System design optimization for a Mars-roving vehicle and perturbed-optimal solutions in nonlinear programming

NASA Technical Reports Server (NTRS)

Pavarini, C.

1974-01-01

Work in two somewhat distinct areas is presented. First, the optimal system design problem for a Mars-roving vehicle is attacked by creating static system models and a system evaluation function and optimizing via nonlinear programming techniques. The second area concerns the problem of perturbed-optimal solutions. Given an initial perturbation in an element of the solution to a nonlinear programming problem, a linear method is determined to approximate the optimal readjustments of the other elements of the solution. Then, the sensitivity of the Mars rover designs is described by application of this method.

Simulating cyber warfare and cyber defenses: information value considerations

NASA Astrophysics Data System (ADS)

Stytz, Martin R.; Banks, Sheila B.

2011-06-01

Simulating cyber warfare is critical to the preparation of decision-makers for the challenges posed by cyber attacks. Simulation is the only means we have to prepare decision-makers for the inevitable cyber attacks upon the information they will need for decision-making and to develop cyber warfare strategies and tactics. Currently, there is no theory regarding the strategies that should be used to achieve objectives in offensive or defensive cyber warfare, and cyber warfare occurs too rarely to use real-world experience to develop effective strategies. To simulate cyber warfare by affecting the information used for decision-making, we modify the information content of the rings that are compromised during in a decision-making context. The number of rings affected and value of the information that is altered (i.e., the closeness of the ring to the center) is determined by the expertise of the decision-maker and the learning outcome(s) for the simulation exercise. We determine which information rings are compromised using the probability that the simulated cyber defenses that protect each ring can be compromised. These probabilities are based upon prior cyber attack activity in the simulation exercise as well as similar real-world cyber attacks. To determine which information in a compromised "ring" to alter, the simulation environment maintains a record of the cyber attacks that have succeeded in the simulation environment as well as the decision-making context. These two pieces of information are used to compute an estimate of the likelihood that the cyber attack can alter, destroy, or falsify each piece of information in a compromised ring. The unpredictability of information alteration in our approach adds greater realism to the cyber event. This paper suggests a new technique that can be used for cyber warfare simulation, the ring approach for modeling context-dependent information value, and our means for considering information value when assigning cyber resources to information protection tasks. The first section of the paper introduces the cyber warfare simulation challenge and the reasons for its importance. The second section contains background information related to our research. The third section contains a discussion of the information ring technique and its use for simulating cyber attacks. The fourth section contains a summary and suggestions for research.

Influence of prehospital airway management on neurological outcome in patients transferred to a heart attack centre following out-of-hospital cardiac arrest.

PubMed

Edwards, Timothy; Williams, Julia; Cottee, Michaela

2018-05-11

To describe the association between prehospital airway management and neurological outcomes in patients transferred by the ambulance service directly to a heart attack centre (HAC) post-return of spontaneous circulation (ROSC). A retrospective observational cohort study in which ambulance records were reviewed to determine prehospital airway management strategy and collect physiological and demographic data. HAC notes were obtained to determine in-hospital management and quantify neurological outcome via the cerebral performance category (CPC) scale. Statistical analyses were performed via χ 2 -test, Mann-Whitney U-test, odds ratios and binomial logistic regression. Two hundred and twenty patients were included between August 2013 and August 2014, with complete outcome data obtained for 209. Median age of patients with complete outcome data was 67 years and 71.3% were male (n = 149). Airway management was provided using a supraglottic airway (SGA) in 72.7% of cases (n = 152) with the remainder undergoing endotracheal intubation (ETI). There was no significant difference in the proportion of patients who had a good neurological outcome (CPC 1 and 2) at discharge between the SGA and ETI groups (P = 0.29). Binomial logistic regression incorporating factors known to influence outcome demonstrated no significant difference in neurological outcomes between the SGA and ETI groups (adjusted OR 0.73, 95% CI 0.34-1.56). In this observational study, there was no significant difference in the proportion of good neurological outcomes in patients managed with SGA versus ETI during cardiac arrest and in the post-ROSC transfer phase. Further research is required to provide more definitive evidence in relation to the optimal airway management strategy in out-of-hospital cardiac arrest. © 2018 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

Network Science Based Quantification of Resilience Demonstrated on the Indian Railways Network.

PubMed

Bhatia, Udit; Kumar, Devashish; Kodra, Evan; Ganguly, Auroop R

2015-01-01

The structure, interdependence, and fragility of systems ranging from power-grids and transportation to ecology, climate, biology and even human communities and the Internet have been examined through network science. While response to perturbations has been quantified, recovery strategies for perturbed networks have usually been either discussed conceptually or through anecdotal case studies. Here we develop a network science based quantitative framework for measuring, comparing and interpreting hazard responses as well as recovery strategies. The framework, motivated by the recently proposed temporal resilience paradigm, is demonstrated with the Indian Railways Network. Simulations inspired by the 2004 Indian Ocean Tsunami and the 2012 North Indian blackout as well as a cyber-physical attack scenario illustrate hazard responses and effectiveness of proposed recovery strategies. Multiple metrics are used to generate various recovery strategies, which are simply sequences in which system components should be recovered after a disruption. Quantitative evaluation of these strategies suggests that faster and more efficient recovery is possible through network centrality measures. Optimal recovery strategies may be different per hazard, per community within a network, and for different measures of partial recovery. In addition, topological characterization provides a means for interpreting the comparative performance of proposed recovery strategies. The methods can be directly extended to other Large-Scale Critical Lifeline Infrastructure Networks including transportation, water, energy and communications systems that are threatened by natural or human-induced hazards, including cascading failures. Furthermore, the quantitative framework developed here can generalize across natural, engineered and human systems, offering an actionable and generalizable approach for emergency management in particular as well as for network resilience in general.

Network Science Based Quantification of Resilience Demonstrated on the Indian Railways Network

PubMed Central

Bhatia, Udit; Kumar, Devashish; Kodra, Evan; Ganguly, Auroop R.

2015-01-01

The structure, interdependence, and fragility of systems ranging from power-grids and transportation to ecology, climate, biology and even human communities and the Internet have been examined through network science. While response to perturbations has been quantified, recovery strategies for perturbed networks have usually been either discussed conceptually or through anecdotal case studies. Here we develop a network science based quantitative framework for measuring, comparing and interpreting hazard responses as well as recovery strategies. The framework, motivated by the recently proposed temporal resilience paradigm, is demonstrated with the Indian Railways Network. Simulations inspired by the 2004 Indian Ocean Tsunami and the 2012 North Indian blackout as well as a cyber-physical attack scenario illustrate hazard responses and effectiveness of proposed recovery strategies. Multiple metrics are used to generate various recovery strategies, which are simply sequences in which system components should be recovered after a disruption. Quantitative evaluation of these strategies suggests that faster and more efficient recovery is possible through network centrality measures. Optimal recovery strategies may be different per hazard, per community within a network, and for different measures of partial recovery. In addition, topological characterization provides a means for interpreting the comparative performance of proposed recovery strategies. The methods can be directly extended to other Large-Scale Critical Lifeline Infrastructure Networks including transportation, water, energy and communications systems that are threatened by natural or human-induced hazards, including cascading failures. Furthermore, the quantitative framework developed here can generalize across natural, engineered and human systems, offering an actionable and generalizable approach for emergency management in particular as well as for network resilience in general. PMID:26536227

Practical, Real-Time, and Robust Watermarking on the Spatial Domain for High-Definition Video Contents

NASA Astrophysics Data System (ADS)

Kim, Kyung-Su; Lee, Hae-Yeoun; Im, Dong-Hyuck; Lee, Heung-Kyu

Commercial markets employ digital right management (DRM) systems to protect valuable high-definition (HD) quality videos. DRM system uses watermarking to provide copyright protection and ownership authentication of multimedia contents. We propose a real-time video watermarking scheme for HD video in the uncompressed domain. Especially, our approach is in aspect of practical perspectives to satisfy perceptual quality, real-time processing, and robustness requirements. We simplify and optimize human visual system mask for real-time performance and also apply dithering technique for invisibility. Extensive experiments are performed to prove that the proposed scheme satisfies the invisibility, real-time processing, and robustness requirements against video processing attacks. We concentrate upon video processing attacks that commonly occur in HD quality videos to display on portable devices. These attacks include not only scaling and low bit-rate encoding, but also malicious attacks such as format conversion and frame rate change.

Creative Persuasion: A Study on Adversarial Behaviors and Strategies in Phishing Attacks

PubMed Central

Rajivan, Prashanth; Gonzalez, Cleotilde

2018-01-01

Success of phishing attacks depend on effective exploitation of human weaknesses. This research explores a largely ignored, but crucial aspect of phishing: the adversarial behavior. We aim at understanding human behaviors and strategies that adversaries use, and how these may determine the end-user response to phishing emails. We accomplish this through a novel experiment paradigm involving two phases. In the adversarial phase, 105 participants played the role of a phishing adversary who were incentivized to produce multiple phishing emails that would evade detection and persuade end-users to respond. In the end-user phase, 340 participants performed an email management task, where they examined and classified phishing emails generated by participants in phase-one along with benign emails. Participants in the adversary role, self-reported the strategies they employed in each email they created, and responded to a test of individual creativity. Data from both phases of the study was combined and analyzed, to measure the effect of adversarial behaviors on end-user response to phishing emails. We found that participants who persistently used specific attack strategies (e.g., sending notifications, use of authoritative tone, or expressing shared interest) in all their attempts were overall more successful, compared to others who explored different strategies in each attempt. We also found that strategies largely determined whether an end-user was more likely to respond to an email immediately, or delete it. Individual creativity was not a reliable predictor of adversarial performance, but it was a predictor of an adversary's ability to evade detection. In summary, the phishing example provided initially, the strategies used, and the participants' persistence with some of the strategies led to higher performance in persuading end-users to respond to phishing emails. These insights may be used to inform tools and training procedures to detect phishing strategies in emails. PMID:29515478

Human Perceptions Mirror Realities of Carnivore Attack Risk for Livestock: Implications for Mitigating Human-Carnivore Conflict

PubMed Central

Miller, Jennifer R. B.; Jhala, Yadvendradev V.; Schmitz, Oswald J.

2016-01-01

Human-carnivore conflict is challenging to quantify because it is shaped by both the realities and people’s perceptions of carnivore threats. Whether perceptions align with realities can have implications for conflict mitigation: misalignments can lead to heightened and indiscriminant persecution of carnivores whereas alignments can offer deeper insights into human-carnivore interactions. We applied a landscape-scale spatial analysis of livestock killed by tigers and leopards in India to model and map observed attack risk, and surveyed owners of livestock killed by tigers and leopards for their rankings of threats across habitats to map perceived attack risk. Observed tiger risk to livestock was greatest near dense forests and at moderate distances from human activity while leopard risk was greatest near open vegetation. People accurately perceived spatial differences between tiger and leopard hunting patterns, expected greater threat in areas with high values of observed risk for both carnivores. Owners’ perception of threats largely did not depend on environmental conditions surrounding their village (spatial location, dominant land-use or observed carnivore risk). Surveys revealed that owners who previously lost livestock to carnivores used more livestock protection methods than those who had no prior losses, and that owners who had recently lost livestock for the first time expressed greater interest in changing their protection methods than those who experienced prior losses. Our findings suggest that in systems where realities and perceptions of carnivore risk align, conservation programs and policies can optimize conservation outcomes by (1) improving the effectiveness of livestock protection methods and (2) working with owners who have recently lost livestock and are most willing to invest effort in adapting protection strategies to mitigate human-carnivore conflict. PMID:27617831

Human Perceptions Mirror Realities of Carnivore Attack Risk for Livestock: Implications for Mitigating Human-Carnivore Conflict.

PubMed

Miller, Jennifer R B; Jhala, Yadvendradev V; Schmitz, Oswald J

2016-01-01

Human-carnivore conflict is challenging to quantify because it is shaped by both the realities and people's perceptions of carnivore threats. Whether perceptions align with realities can have implications for conflict mitigation: misalignments can lead to heightened and indiscriminant persecution of carnivores whereas alignments can offer deeper insights into human-carnivore interactions. We applied a landscape-scale spatial analysis of livestock killed by tigers and leopards in India to model and map observed attack risk, and surveyed owners of livestock killed by tigers and leopards for their rankings of threats across habitats to map perceived attack risk. Observed tiger risk to livestock was greatest near dense forests and at moderate distances from human activity while leopard risk was greatest near open vegetation. People accurately perceived spatial differences between tiger and leopard hunting patterns, expected greater threat in areas with high values of observed risk for both carnivores. Owners' perception of threats largely did not depend on environmental conditions surrounding their village (spatial location, dominant land-use or observed carnivore risk). Surveys revealed that owners who previously lost livestock to carnivores used more livestock protection methods than those who had no prior losses, and that owners who had recently lost livestock for the first time expressed greater interest in changing their protection methods than those who experienced prior losses. Our findings suggest that in systems where realities and perceptions of carnivore risk align, conservation programs and policies can optimize conservation outcomes by (1) improving the effectiveness of livestock protection methods and (2) working with owners who have recently lost livestock and are most willing to invest effort in adapting protection strategies to mitigate human-carnivore conflict.

Technology Against Terrorism: Structuring Security

DTIC Science & Technology

1992-01-01

outbreak of non is global in scope and, unfortunately, continues hostilities in January 1991, the number of interna- to demand attention and protective...against non -combatants, ranging from attacks on clinics by foes of abortion to mass murder by sophisticated international terrorist groups (e.g., attacks...findings were reached The fourth chapter discusses strategies for design - that involved first, the overall Federal funding of ing integrated systems

A Dynamic Game on Network Topology for Counterinsurgency Applications

DTIC Science & Technology

2015-03-26

scenario. This study creates a dynamic game on network topology to provide insight into the effec- tiveness of offensive targeting strategies determined by...focused upon the diffusion of thoughts and innovations throughout complex social networks. Coleman et al. (1966) and Ryan & Gross (1950) investigated...free networks make them extremely resilient against errors but very vulnerable to attack. Most interest- ingly, a determined attacker can remove well

DOE Office of Scientific and Technical Information (OSTI.GOV)

Filip, Radim; Marek, Petr; Fiurasek, Jaromir

We analyze a reversibility of optimal Gaussian 1{yields}2 quantum cloning of a coherent state using only local operations on the clones and classical communication between them and propose a feasible experimental test of this feature. Performing Bell-type homodyne measurement on one clone and anticlone, an arbitrary unknown input state (not only a coherent state) can be restored in the other clone by applying appropriate local unitary displacement operation. We generalize this concept to a partial reversal of the cloning using only local operations and classical communication (LOCC) and we show that this procedure converts the symmetric cloner to an asymmetricmore » cloner. Further, we discuss a distributed LOCC reversal in optimal 1{yields}M Gaussian cloning of coherent states which transforms it to optimal 1{yields}M{sup '} cloning for M{sup '}

Optimism and death: predicting the course and consequences of depression trajectories in response to heart attack.

PubMed

Galatzer-Levy, Isaac R; Bonanno, George A

2014-12-01

The course of depression in relation to myocardial infarction (MI), commonly known as heart attack, and the consequences for mortality are not well characterized. Further, optimism may predict both the effects of MI on depression as well as mortality secondary to MI. In the current study, we utilized a large population-based prospective sample of older adults (N=2,147) to identify heterogeneous trajectories of depression from 6 years prior to their first-reported MI to 4 years after. Findings indicated that individuals were at significantly increased risk for mortality when depression emerged after their first-reported MI, compared with resilient individuals who had no significant post-MI elevation in depression symptomatology. Individuals with chronic depression and those demonstrating pre-event depression followed by recovery after MI were not at increased risk. Further, optimism, measured before MI, prospectively differentiated all depressed individuals from participants who were resilient. © The Author(s) 2014.

Adjoint Airfoil Optimization of Darrieus-Type Vertical Axis Wind Turbine

NASA Astrophysics Data System (ADS)

Fuchs, Roman; Nordborg, Henrik

2012-11-01

We present the feasibility of using an adjoint solver to optimize the torque of a Darrieus-type vertical axis wind turbine (VAWT). We start with a 2D cross section of a symmetrical airfoil and restrict us to low solidity ratios to minimize blade vortex interactions. The adjoint solver of the ANSYS FLUENT software package computes the sensitivities of airfoil surface forces based on a steady flow field. Hence, we find the torque of a full revolution using a weighted average of the sensitivities at different wind speeds and angles of attack. The weights are computed analytically, and the range of angles of attack is given by the tip speed ratio. Then the airfoil geometry is evolved, and the proposed methodology is evaluated by transient simulations.

Characterization of attacks on public telephone networks

NASA Astrophysics Data System (ADS)

Lorenz, Gary V.; Manes, Gavin W.; Hale, John C.; Marks, Donald; Davis, Kenneth; Shenoi, Sujeet

2001-02-01

The U.S. Public Telephone Network (PTN) is a massively connected distributed information systems, much like the Internet. PTN signaling, transmission and operations functions must be protected from physical and cyber attacks to ensure the reliable delivery of telecommunications services. The increasing convergence of PTNs with wireless communications systems, computer networks and the Internet itself poses serious threats to our nation's telecommunications infrastructure. Legacy technologies and advanced services encumber well-known and as of yet undiscovered vulnerabilities that render them susceptible to cyber attacks. This paper presents a taxonomy of cyber attacks on PTNs in converged environments that synthesizes exploits in computer and communications network domains. The taxonomy provides an opportunity for the systematic exploration of mitigative and preventive strategies, as well as for the identification and classification of emerging threats.

The ecology of human fear: survival optimization and the nervous system

PubMed Central

Mobbs, Dean; Hagan, Cindy C.; Dalgleish, Tim; Silston, Brian; Prévost, Charlotte

2015-01-01

We propose a Survival Optimization System (SOS) to account for the strategies that humans and other animals use to defend against recurring and novel threats. The SOS attempts to merge ecological models that define a repertoire of contextually relevant threat induced survival behaviors with contemporary approaches to human affective science. We first propose that the goal of the nervous system is to reduce surprise and optimize actions by (i) predicting the sensory landscape by simulating possible encounters with threat and selecting the appropriate pre-encounter action and (ii) prevention strategies in which the organism manufactures safe environments. When a potential threat is encountered the (iii) threat orienting system is engaged to determine whether the organism ignores the stimulus or switches into a process of (iv) threat assessment, where the organism monitors the stimulus, weighs the threat value, predicts the actions of the threat, searches for safety, and guides behavioral actions crucial to directed escape. When under imminent attack, (v) defensive systems evoke fast reflexive indirect escape behaviors (i.e., fight or flight). This cascade of responses to threat of increasing magnitude are underwritten by an interconnected neural architecture that extends from cortical and hippocampal circuits, to attention, action and threat systems including the amygdala, striatum, and hard-wired defensive systems in the midbrain. The SOS also includes a modulatory feature consisting of cognitive appraisal systems that flexibly guide perception, risk and action. Moreover, personal and vicarious threat encounters fine-tune avoidance behaviors via model-based learning, with higher organisms bridging data to reduce face-to-face encounters with predators. Our model attempts to unify the divergent field of human affective science, proposing a highly integrated nervous system that has evolved to increase the organism's chances of survival. PMID:25852451

Visualization of the Serratia Type VI Secretion System Reveals Unprovoked Attacks and Dynamic Assembly

PubMed Central

Gerc, Amy J.; Diepold, Andreas; Trunk, Katharina; Porter, Michael; Rickman, Colin; Armitage, Judith P.; Stanley-Wall, Nicola R.; Coulthurst, Sarah J.

2015-01-01

Summary The Type VI secretion system (T6SS) is a bacterial nanomachine that fires toxic proteins into target cells. Deployment of the T6SS represents an efficient and widespread means by which bacteria attack competitors or interact with host organisms and may be triggered by contact from an attacking neighbor cell as a defensive strategy. Here, we use the opportunist pathogen Serratia marcescens and functional fluorescent fusions of key components of the T6SS to observe different subassemblies of the machinery simultaneously and on multiple timescales in vivo. We report that the localization and dynamic behavior of each of the components examined is distinct, revealing a multi-stage and dynamic assembly process for the T6SS machinery. We also show that the T6SS can assemble and fire without needing a cell contact trigger, defining an aggressive strategy that broadens target range and suggesting that activation of the T6SS is tailored to survival in specific niches. PMID:26387948

Bartonella and Brucella—Weapons and Strategies for Stealth Attack

PubMed Central

Ben-Tekaya, Houchaima; Gorvel, Jean-Pierre; Dehio, Christoph

2013-01-01

Bartonella spp. and Brucella spp. are closely related α-proteobacterial pathogens that by distinct stealth-attack strategies cause chronic infections in mammals including humans. Human infections manifest by a broad spectrum of clinical symptoms, ranging from mild to fatal disease. Both pathogens establish intracellular replication niches and subvert diverse pathways of the host’s immune system. Several virulence factors allow them to adhere to, invade, proliferate, and persist within various host-cell types. In particular, type IV secretion systems (T4SS) represent essential virulence factors that transfer effector proteins tailored to recruit host components and modulate cellular processes to the benefit of the bacterial intruders. This article puts the remarkable features of these two pathogens into perspective, highlighting the mechanisms they use to hijack signaling and trafficking pathways of the host as the basis for their stealthy infection strategies. PMID:23906880

Systematic review of strategies to manage and allocate scarce resources during mass casualty events.

PubMed

Timbie, Justin W; Ringel, Jeanne S; Fox, D Steven; Pillemer, Francesca; Waxman, Daniel A; Moore, Melinda; Hansen, Cynthia K; Knebel, Ann R; Ricciardi, Richard; Kellermann, Arthur L

2013-06-01

Efficient management and allocation of scarce medical resources can improve outcomes for victims of mass casualty events. However, the effectiveness of specific strategies has never been systematically reviewed. We analyze published evidence on strategies to optimize the management and allocation of scarce resources across a wide range of mass casualty event contexts and study designs. Our literature search included MEDLINE, Scopus, EMBASE, Cumulative Index to Nursing and Allied Health Literature, Global Health, Web of Science, and the Cochrane Database of Systematic Reviews, from 1990 through late 2011. We also searched the gray literature, using the New York Academy of Medicine's Grey Literature Report and key Web sites. We included both English- and foreign-language articles. We included studies that evaluated strategies used in actual mass casualty events or tested through drills, exercises, or computer simulations. We excluded studies that lacked a comparison group or did not report quantitative outcomes. Data extraction, quality assessment, and strength of evidence ratings were conducted by a single researcher and reviewed by a second; discrepancies were reconciled by the 2 reviewers. Because of heterogeneity in outcome measures, we qualitatively synthesized findings within categories of strategies. From 5,716 potentially relevant citations, 74 studies met inclusion criteria. Strategies included reducing demand for health care services (18 studies), optimizing use of existing resources (50), augmenting existing resources (5), implementing crisis standards of care (5), and multiple categories (4). The evidence was sufficient to form conclusions on 2 strategies, although the strength of evidence was rated as low. First, as a strategy to reduce demand for health care services, points of dispensing can be used to efficiently distribute biological countermeasures after a bioterrorism attack or influenza pandemic, and their organization influences speed of distribution. Second, as a strategy to optimize use of existing resources, commonly used field triage systems do not perform consistently during actual mass casualty events. The number of high-quality studies addressing other strategies was insufficient to support conclusions about their effectiveness because of differences in study context, comparison groups, and outcome measures. Our literature search may have missed key resource management and allocation strategies because of their extreme heterogeneity. Interrater reliability was not assessed for quality assessments or strength of evidence ratings. Publication bias is likely, given the large number of studies reporting positive findings. The current evidence base is inadequate to inform providers and policymakers about the most effective strategies for managing or allocating scarce resources during mass casualty events. Consensus on methodological standards that encompass a range of study designs is needed to guide future research and strengthen the evidence base. Evidentiary standards should be developed to promote consensus interpretations of the evidence supporting individual strategies. Copyright © 2013 American College of Emergency Physicians. Published by Mosby, Inc. All rights reserved.

Vulnerability analysis and critical areas identification of the power systems under terrorist attacks

NASA Astrophysics Data System (ADS)

Wang, Shuliang; Zhang, Jianhua; Zhao, Mingwei; Min, Xu

2017-05-01

This paper takes central China power grid (CCPG) as an example, and analyzes the vulnerability of the power systems under terrorist attacks. To simulate the intelligence of terrorist attacks, a method of critical attack area identification according to community structures is introduced. Meanwhile, three types of vulnerability models and the corresponding vulnerability metrics are given for comparative analysis. On this basis, influence of terrorist attacks on different critical areas is studied. Identifying the vulnerability of different critical areas will be conducted. At the same time, vulnerabilities of critical areas under different tolerance parameters and different vulnerability models are acquired and compared. Results show that only a few number of vertex disruptions may cause some critical areas collapse completely, they can generate great performance losses the whole systems. Further more, the variation of vulnerability values under different scenarios is very large. Critical areas which can cause greater damage under terrorist attacks should be given priority of protection to reduce vulnerability. The proposed method can be applied to analyze the vulnerability of other infrastructure systems, they can help decision makers search mitigation action and optimum protection strategy.

Improving the management and referral of patients with transient ischaemic attacks: a change strategy for a health community

PubMed Central

Wright, J; Harrison, S; McGeorge, M; Patterson, C; Russell, I; Russell, D; Small, N; Taylor, M; Walsh, M; Warren, E; Young, J

2006-01-01

Problem Rapid referral and management of patients with transient ischaemic attacks is a key component in the national strategy for stroke prevention. However, patients with transient ischaemic attacks are poorly identified and undertreated. Design and setting Before and after evaluation of quality improvement programme with controlled comparison in three primary care trusts reflecting diverse populations and organisational structures in an urban district in the North of England. Key measures for improvement The proportion of patients receiving antiplatelet drugs and safe driving advice on referral to a speciality clinic, and the numbers of referrals, adjusted for age, to the specialist clinic before and after the improvement programme. Strategies for change Interviews with patient and professionals to identify gaps and barriers to good practice; development of evidence based guidelines for the management of patients with transient ischaemic attacks; interactive multidisciplinary workshops for each primary care trust with feedback of individual audit results of referral practice; outreach visits to teams who were unable to attend the workshops; referral templates and desktop summaries to provide reminders of the guidelines to clinicians; incorporation of standards into professional contracts. Effects of change A significant improvement occurred in identification and referral of patients with transient ischaemic attacks to specialist clinics, with a 41% increase in referrals from trained practices compared with control practices. There were also significant improvements in the early treatment and safety advice provided to patients before referral. Lessons learnt A strategic approach to effective quality improvement across a diverse health community is feasible and achievable. Careful planning with patient and professional involvement to develop a tailored and multifaceted quality improvement programme to implement evidence based practice can work in very different primary care settings. Key components of the effectiveness of the model include contextual analysis, strong professional support, clear recommendations based on robust evidence, simplicity of adoption, good communication, and use of established networks and opinion leaders. PMID:16456203

Colombia’s National Security Strategy, A New COIN Approach

DTIC Science & Technology

2008-03-07

theory by the book. Massive attacks over platoon, company and even battalion size posts , became part of the country’s life. Surprise attacks over the...peace process failure. Also, these threats had the purpose of coercing all presidential candidates and their electorate . Indiscriminate terrorist...Eduardo Pizarro, Una Democracia Asediada, Balance y Perspectivas del Conflicto Armado en Colombia (Bogotá: Grupo Editorial Norma, Marzo 2004), 94. 24

Extended Deterrence and Allied Assurance: Key Concepts and Current Challenges for U.S. Policy

DTIC Science & Technology

2013-09-01

include adversary nuclear forces and stockpiles) in the pre- satellite era required a strategy using large numbers of bombers, large numbers of...radar and sensor capabilities related to TMD, activities Canberra considered important to “bolstering 59 the [U.S.-Australia] alliance.” 146 In...external attack; with potential adversaries developing anti- satellite 90 capabilities, and conducting cyber incursions and attacks against U.S. and

Research on Network Defense Strategy Based on Honey Pot Technology

NASA Astrophysics Data System (ADS)

Hong, Jianchao; Hua, Ying

2018-03-01

As a new network security technology of active defense, The honeypot technology has become a very effective and practical method of decoy attackers. The thesis discusses the theory, structure, characteristic, design and implementation of Honeypot in detail. Aiming at the development of means of attack, put forward a kind of network defense technology based on honeypot technology, constructing a virtual Honeypot demonstrate the honeypot’s functions.

Phytohormone mediation of interactions between herbivores and plant pathogens.

PubMed

Lazebnik, Jenny; Frago, Enric; Dicke, Marcel; van Loon, Joop J A

2014-07-01

Induced plant defenses against either pathogens or herbivore attackers are regulated by phytohormones. These phytohormones are increasingly recognized as important mediators of interactions between organisms associated with plants. In this review, we discuss the role of plant defense hormones in sequential tri-partite interactions among plants, pathogenic microbes, and herbivorous insects, based on the most recent literature. We discuss the importance of pathogen trophic strategy in the interaction with herbivores that exhibit different feeding modes. Plant resistance mechanisms also affect plant quality in future interactions with attackers. We discuss exemplary evidence for the hypotheses that (i) biotrophic pathogens can facilitate chewing herbivores, unless plants exhibit effector-triggered immunity, but (ii) facilitate or inhibit phloem feeders. (iii) Necrotrophic pathogens, on the other hand, can inhibit both phloem feeders and chewers. We also propose herbivore feeding mode as predictor of effects on pathogens of different trophic strategies, providing evidence for the hypotheses that (iv) phloem feeders inhibit pathogen attack by increasing SA induction, whereas (v) chewing herbivores tend not to affect necrotrophic pathogens, while they may either inhibit or facilitate biotrophic pathogens. Putting these hypotheses to the test will increase our understanding of phytohormonal regulation of plant defense to sequential attack by plant pathogens and insect herbivores. This will provide valuable insight into plant-mediated ecological interactions among members of the plant-associated community.

Composable security proof for continuous-variable quantum key distribution with coherent States.

PubMed

Leverrier, Anthony

2015-02-20

We give the first composable security proof for continuous-variable quantum key distribution with coherent states against collective attacks. Crucially, in the limit of large blocks the secret key rate converges to the usual value computed from the Holevo bound. Combining our proof with either the de Finetti theorem or the postselection technique then shows the security of the protocol against general attacks, thereby confirming the long-standing conjecture that Gaussian attacks are optimal asymptotically in the composable security framework. We expect that our parameter estimation procedure, which does not rely on any assumption about the quantum state being measured, will find applications elsewhere, for instance, for the reliable quantification of continuous-variable entanglement in finite-size settings.

Low-speed longitudinal and lateral-directional aerodynamic characteristics of the X-31 configuration

NASA Technical Reports Server (NTRS)

Banks, Daniel W.; Gatlin, Gregory M.; Paulson, John W., Jr.

1992-01-01

An experimental investigation of a 19 pct. scale model of the X-31 configuration was completed in the Langley 14 x 22 Foot Subsonic Tunnel. This study was performed to determine the static low speed aerodynamic characteristics of the basic configuration over a large range of angle of attack and sideslip and to study the effects of strakes, leading-edge extensions (wing-body strakes), nose booms, speed-brake deployment, and inlet configurations. The ultimate purpose was to optimize the configuration for high angle of attack and maneuvering-flight conditions. The model was tested at angles of attack from -5 to 67 deg and at sideslip angles from -16 to 16 deg for speeds up to 190 knots (dynamic pressure of 120 psf).

Robust shot-noise measurement for continuous-variable quantum key distribution

NASA Astrophysics Data System (ADS)

Kunz-Jacques, Sébastien; Jouguet, Paul

2015-02-01

We study a practical method to measure the shot noise in real time in continuous-variable quantum key distribution systems. The amount of secret key that can be extracted from the raw statistics depends strongly on this quantity since it affects in particular the computation of the excess noise (i.e., noise in excess of the shot noise) added by an eavesdropper on the quantum channel. Some powerful quantum hacking attacks relying on faking the estimated value of the shot noise to hide an intercept and resend strategy were proposed. Here, we provide experimental evidence that our method can defeat the saturation attack and the wavelength attack.

Level I center triage and mass casualties.

PubMed

Hoey, Brian A; Schwab, C William

2004-05-01

The world has been marked by a recent series of high-profile terrorist attacks, including the attack of September 11, 2001, in New York City. Similar to natural disasters, these attacks often result in a large number of casualties necessitating triage strategies. The end of the twentieth century was marked by the development of trauma systems in the United States and abroad. By their very nature, trauma centers are best equipped to handle mass casualties resulting from natural and manmade disasters. Triage assessment tools and scoring systems have evolved to facilitate this triage process and to potentially reduce the morbidity and mortality associated with these events.

Experimental Optimization Methods for Multi-Element Airfoils

NASA Technical Reports Server (NTRS)

Landman, Drew; Britcher, Colin P.

1996-01-01

A modern three element airfoil model with a remotely activated flap was used to investigate optimum flap testing position using an automated optimization algorithm in wind tunnel tests. Detailed results for lift coefficient versus flap vertical and horizontal position are presented for two angles of attack: 8 and 14 degrees. An on-line first order optimizer is demonstrated which automatically seeks the optimum lift as a function of flap position. Future work with off-line optimization techniques is introduced and aerodynamic hysteresis effects due to flap movement with flow on are discussed.

Optimization and guidance of flight trajectories for the national aerospace plane

NASA Technical Reports Server (NTRS)

Miele, Angelo

1990-01-01

The research on optimal trajectories for the National Aerospace Plane (NASP) performed by the Aero-Astronautics Group of Rice University from June 22, 1989 to December 31, 1990 is summarized. The aerospace plane is assumed to be controlled via the angle of attack and the power setting. The time history of the controls is optimized simultaneously with the switch times from one powerplant to another and the final time. The intent is to arrive at NASP guidance trajectories exhibiting many of the desirable characteristics of NASP optimal trajectories.

Eavesdropping-aware routing and spectrum allocation based on multi-flow virtual concatenation for confidential information service in elastic optical networks

NASA Astrophysics Data System (ADS)

Bai, Wei; Yang, Hui; Yu, Ao; Xiao, Hongyun; He, Linkuan; Feng, Lei; Zhang, Jie

2018-01-01

The leakage of confidential information is one of important issues in the network security area. Elastic Optical Networks (EON) as a promising technology in the optical transport network is under threat from eavesdropping attacks. It is a great demand to support confidential information service (CIS) and design efficient security strategy against the eavesdropping attacks. In this paper, we propose a solution to cope with the eavesdropping attacks in routing and spectrum allocation. Firstly, we introduce probability theory to describe eavesdropping issue and achieve awareness of eavesdropping attacks. Then we propose an eavesdropping-aware routing and spectrum allocation (ES-RSA) algorithm to guarantee information security. For further improving security and network performance, we employ multi-flow virtual concatenation (MFVC) and propose an eavesdropping-aware MFVC-based secure routing and spectrum allocation (MES-RSA) algorithm. The presented simulation results show that the proposed two RSA algorithms can both achieve greater security against the eavesdropping attacks and MES-RSA can also improve the network performance efficiently.

Optimal Level of Expenditure to Control the Southern Pine Beetle

Treesearch

Joseph E. de Steiguer; Roy L. Hedden; John M. Pye

1987-01-01

Optimal level of expenditure to control damage to commercial timber stands by the southern pine beetle was determined by models that simulated and analyzed beetle attacks during a typical season for 11 Southern States. At a real discount rate of 4 percent, maximized net benefits for the Southern region are estimated at about $50 million; at 10 percent, more than $30...

Optimization of controllability and robustness of complex networks by edge directionality

NASA Astrophysics Data System (ADS)

Liang, Man; Jin, Suoqin; Wang, Dingjie; Zou, Xiufen

2016-09-01

Recently, controllability of complex networks has attracted enormous attention in various fields of science and engineering. How to optimize structural controllability has also become a significant issue. Previous studies have shown that an appropriate directional assignment can improve structural controllability; however, the evolution of the structural controllability of complex networks under attacks and cascading has always been ignored. To address this problem, this study proposes a new edge orientation method (NEOM) based on residual degree that changes the link direction while conserving topology and directionality. By comparing the results with those of previous methods in two random graph models and several realistic networks, our proposed approach is demonstrated to be an effective and competitive method for improving the structural controllability of complex networks. Moreover, numerical simulations show that our method is near-optimal in optimizing structural controllability. Strikingly, compared to the original network, our method maintains the structural controllability of the network under attacks and cascading, indicating that the NEOM can also enhance the robustness of controllability of networks. These results alter the view of the nature of controllability in complex networks, change the understanding of structural controllability and affect the design of network models to control such networks.

Game Theory Meets Wireless Sensor Networks Security Requirements and Threats Mitigation: A Survey.

PubMed

Abdalzaher, Mohamed S; Seddik, Karim; Elsabrouty, Maha; Muta, Osamu; Furukawa, Hiroshi; Abdel-Rahman, Adel

2016-06-29

We present a study of using game theory for protecting wireless sensor networks (WSNs) from selfish behavior or malicious nodes. Due to scalability, low complexity and disseminated nature of WSNs, malicious attacks can be modeled effectively using game theory. In this study, we survey the different game-theoretic defense strategies for WSNs. We present a taxonomy of the game theory approaches based on the nature of the attack, whether it is caused by an external attacker or it is the result of an internal node acting selfishly or maliciously. We also present a general trust model using game theory for decision making. We, finally, identify the significant role of evolutionary games for WSNs security against intelligent attacks; then, we list several prospect applications of game theory to enhance the data trustworthiness and node cooperation in different WSNs.

An engineering optimization method with application to STOL-aircraft approach and landing trajectories

NASA Technical Reports Server (NTRS)

Jacob, H. G.

1972-01-01

An optimization method has been developed that computes the optimal open loop inputs for a dynamical system by observing only its output. The method reduces to static optimization by expressing the inputs as series of functions with parameters to be optimized. Since the method is not concerned with the details of the dynamical system to be optimized, it works for both linear and nonlinear systems. The method and the application to optimizing longitudinal landing paths for a STOL aircraft with an augmented wing are discussed. Noise, fuel, time, and path deviation minimizations are considered with and without angle of attack, acceleration excursion, flight path, endpoint, and other constraints.

Strategic Word Attack: Acquired Contextual Strategies in Young Readers.

ERIC Educational Resources Information Center

Matz, Karl A.

A study demonstrated that young children who have difficulty with phonics can be taught to read through other methods, that phonics is only one of the many useful strategies that a child can employ, and that many contextual strategies are easier to learn and more reliable than phonics. A case study was conducted during an intervention with a young…

Traumatic stress symptoms after the November 13th 2015 Terrorist Attacks among Young Adults: The relation to media and emotion regulation.

PubMed

Monfort, Emmanuel; Afzali, Mohammad Hassan

2017-05-01

A major terror attack occurred in the Paris region on 13th November 2015. This event was widely showed, described, and commented in the media. Media consumption may lead to a widespread diffusion of trauma-related symptoms following a collective trauma. These effects may depend on the type of media and emotion regulation strategies used by the media consumer. Trauma history, traumatic symptoms, media consumption, psychological distress, and emotion regulation strategies of 451 young adults were assessed by an online survey. Findings reveal the joint role of social networks use and dysfunctional emotion regulation strategies on anxiety, depression, and somatization symptoms and also on cognitive and emotional alteration among traumatic symptoms. Consistent with the emotional contagion hypothesis, individuals who reported spending more time on social networks were also those who were experiencing more psychological distress. Copyright © 2017 Elsevier Inc. All rights reserved.

Limits of Predictability of Cascading Overload Failures in Spatially-Embedded Networks with Distributed Flows.

PubMed

Moussawi, A; Derzsy, N; Lin, X; Szymanski, B K; Korniss, G

2017-09-15

Cascading failures are a critical vulnerability of complex information or infrastructure networks. Here we investigate the properties of load-based cascading failures in real and synthetic spatially-embedded network structures, and propose mitigation strategies to reduce the severity of damages caused by such failures. We introduce a stochastic method for optimal heterogeneous distribution of resources (node capacities) subject to a fixed total cost. Additionally, we design and compare the performance of networks with N-stable and (N-1)-stable network-capacity allocations by triggering cascades using various real-world node-attack and node-failure scenarios. We show that failure mitigation through increased node protection can be effectively achieved against single-node failures. However, mitigating against multiple node failures is much more difficult due to the combinatorial increase in possible sets of initially failing nodes. We analyze the robustness of the system with increasing protection, and find that a critical tolerance exists at which the system undergoes a phase transition, and above which the network almost completely survives an attack. Moreover, we show that cascade-size distributions measured in this region exhibit a power-law decay. Finally, we find a strong correlation between cascade sizes induced by individual nodes and sets of nodes. We also show that network topology alone is a weak predictor in determining the progression of cascading failures.

Risk-based decision making for staggered bioterrorist attacks : resource allocation and risk reduction in "reload" scenarios.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lemaster, Michelle Nicole; Gay, David M.; Ehlen, Mark Andrew

2009-10-01

Staggered bioterrorist attacks with aerosolized pathogens on population centers present a formidable challenge to resource allocation and response planning. The response and planning will commence immediately after the detection of the first attack and with no or little information of the second attack. In this report, we outline a method by which resource allocation may be performed. It involves probabilistic reconstruction of the bioterrorist attack from partial observations of the outbreak, followed by an optimization-under-uncertainty approach to perform resource allocations. We consider both single-site and time-staggered multi-site attacks (i.e., a reload scenario) under conditions when resources (personnel and equipment whichmore » are difficult to gather and transport) are insufficient. Both communicable (plague) and non-communicable diseases (anthrax) are addressed, and we also consider cases when the data, the time-series of people reporting with symptoms, are confounded with a reporting delay. We demonstrate how our approach develops allocations profiles that have the potential to reduce the probability of an extremely adverse outcome in exchange for a more certain, but less adverse outcome. We explore the effect of placing limits on daily allocations. Further, since our method is data-driven, the resource allocation progressively improves as more data becomes available.« less

Security attack detection algorithm for electric power gis system based on mobile application

NASA Astrophysics Data System (ADS)

Zhou, Chao; Feng, Renjun; Wang, Liming; Huang, Wei; Guo, Yajuan

2017-05-01

Electric power GIS is one of the key information technologies to satisfy the power grid construction in China, and widely used in power grid construction planning, weather, and power distribution management. The introduction of electric power GIS based on mobile applications is an effective extension of the geographic information system that has been widely used in the electric power industry. It provides reliable, cheap and sustainable power service for the country. The accurate state estimation is the important conditions to maintain the normal operation of the electric power GIS. Recent research has shown that attackers can inject the complex false data into the power system. The injection attack of this new type of false data (load integrity attack LIA) can successfully bypass the routine detection to achieve the purpose of attack, so that the control center will make a series of wrong decision. Eventually, leading to uneven distribution of power in the grid. In order to ensure the safety of the electric power GIS system based on mobile application, it is very important to analyze the attack mechanism and propose a new type of attack, and to study the corresponding detection method and prevention strategy in the environment of electric power GIS system based on mobile application.

Impact modeling and prediction of attacks on cyber targets

NASA Astrophysics Data System (ADS)

Khalili, Aram; Michalk, Brian; Alford, Lee; Henney, Chris; Gilbert, Logan

2010-04-01

In most organizations, IT (information technology) infrastructure exists to support the organization's mission. The threat of cyber attacks poses risks to this mission. Current network security research focuses on the threat of cyber attacks to the organization's IT infrastructure; however, the risks to the overall mission are rarely analyzed or formalized. This connection of IT infrastructure to the organization's mission is often neglected or carried out ad-hoc. Our work bridges this gap and introduces analyses and formalisms to help organizations understand the mission risks they face from cyber attacks. Modeling an organization's mission vulnerability to cyber attacks requires a description of the IT infrastructure (network model), the organization mission (business model), and how the mission relies on IT resources (correlation model). With this information, proper analysis can show which cyber resources are of tactical importance in a cyber attack, i.e., controlling them enables a large range of cyber attacks. Such analysis also reveals which IT resources contribute most to the organization's mission, i.e., lack of control over them gravely affects the mission. These results can then be used to formulate IT security strategies and explore their trade-offs, which leads to better incident response. This paper presents our methodology for encoding IT infrastructure, organization mission and correlations, our analysis framework, as well as initial experimental results and conclusions.

Immigrant Integration: A Missing Component of Homeland Security Strategy and Policy

DTIC Science & Technology

2010-03-01

Kobach, 2007). JFK airport in New York (Kobach, 2007) The four JFK terrorists include two nationals of Guyana, one of Trinidad, and one former...words of the terrorist themselves. In one conversation taped by the FBI, Defreitas (the lead plotter of the thwarted attack at JFK airport in...another recorded conversation with his conspirators in May 2007, Defreitas compared the plot to attack JFK airport with the September 11, 2001

Bayes, Bugs, and Bioterrorists: Lessons Learned from the Anthrax Attacks

DTIC Science & Technology

2005-04-01

characteristics of Bacillus anthracis, the causative organism. Anthrax was known primarily as a disease of cattle, sheep, and other types of livestock, but it...REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Bayes, Bugs, and Bioterrorists: Lessons Learned from the Anthrax Attacks 5a. CONTRACT...develop a strategy for managing the risks of bioterrorism. Using this type of approach, the government can better characterize the costs, risks and

Development of corrosion resistant heat exchangers for flue gas desulfurization

NASA Astrophysics Data System (ADS)

Ernst, E.; Lorentz, R.

1984-12-01

A glass lining as protection against corrosion in flue gas desulfurization plants was developed. Glasses were evaluated under corrosive attack of fluoride-containing acids. The corrosion properties of one-layer and two-layer glass enamels are optimized. Two-layer systems always show better resistance and longer life. The optimized glass linings were tested in a power plant. Manufacturing principles for glass-lined heat exchanger elements are derived. The optimized glasses may be used as protective lining design for heat exchangers or parts of them.

Education and non-pharmacological approaches for gout.

PubMed

Abhishek, Abhishek; Doherty, Michael

2018-01-01

The objectives of this review are as follows: to highlight the gaps in patient and physician knowledge of gout and how this might impede optimal disease management; to provide recommended core knowledge points that should be conveyed to people with gout; and to review non-pharmacological interventions that can be used in gout management. MeSH terms were used to identify eligible studies examining patients' and health-care professionals' knowledge about gout and its management. A narrative review of non-pharmacological management of gout is provided. Many health-care professionals have significant gaps in their knowledge about gout that have the potential to impede optimal management. Likewise, people with gout and the general population lack knowledge about causes, consequences and treatment of this condition. Full explanation about gout, including the potential benefits of urate-lowering treatment (ULT), motivates people with gout to want to start such treatment, and there is evidence, albeit limited, that educational interventions can improve uptake and adherence to ULT. Additionally, several non-pharmacological approaches, such as rest and topical ice application for acute attacks, avoidance of risk factors that can trigger acute attacks, and dietary interventions that may reduce gout attack frequency (e.g. cherry or cherry juice extract, skimmed milk powder or omega-3 fatty acid intake) or lower serum uric acid (e.g. vitamin C), can be used as adjuncts to ULT. There is a pressing need to educate health-care professionals, people with gout and society at large to remove the negative stereotypes associated with gout, which serve as barriers to optimal gout management, and to perceive gout as a significant medical condition. Moreover, there is a paucity of high-quality trial evidence on whether certain simple individual dietary and lifestyle factors can reduce the risk of recurrent gout attacks, and further studies are required in this field. © The Author 2018. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A Systems Engineering Framework for Implementing a Security and Critical Patch Management Process in Diverse Environments (Academic Departments' Workstations)

NASA Astrophysics Data System (ADS)

Mohammadi, Hadi

Use of the Patch Vulnerability Management (PVM) process should be seriously considered for any networked computing system. The PVM process prevents the operating system (OS) and software applications from being attacked due to security vulnerabilities, which lead to system failures and critical data leakage. The purpose of this research is to create and design a Security and Critical Patch Management Process (SCPMP) framework based on Systems Engineering (SE) principles. This framework will assist Information Technology Department Staff (ITDS) to reduce IT operating time and costs and mitigate the risk of security and vulnerability attacks. Further, this study evaluates implementation of the SCPMP in the networked computing systems of an academic environment in order to: 1. Meet patch management requirements by applying SE principles. 2. Reduce the cost of IT operations and PVM cycles. 3. Improve the current PVM methodologies to prevent networked computing systems from becoming the targets of security vulnerability attacks. 4. Embed a Maintenance Optimization Tool (MOT) in the proposed framework. The MOT allows IT managers to make the most practicable choice of methods for deploying and installing released patches and vulnerability remediation. In recent years, there has been a variety of frameworks for security practices in every networked computing system to protect computer workstations from becoming compromised or vulnerable to security attacks, which can expose important information and critical data. I have developed a new mechanism for implementing PVM for maximizing security-vulnerability maintenance, protecting OS and software packages, and minimizing SCPMP cost. To increase computing system security in any diverse environment, particularly in academia, one must apply SCPMP. I propose an optimal maintenance policy that will allow ITDS to measure and estimate the variation of PVM cycles based on their department's requirements. My results demonstrate that MOT optimizes the process of implementing SCPMP in academic workstations.

Developing a Media Moisture Threshold for Nurseries to Reduce Tree Stress and Ambrosia Beetle Attacks.

PubMed

Frank, Steven D; Ranger, Christopher M

2016-08-01

Exotic ambrosia beetles are among the most damaging pests of trees grown in nurseries. The primary pests Xylosandrus crassiusculus Motschulsky and Xylosandrus germanus Blandford use ethanol to locate vulnerable trees. Research, primarily with X. germanus, has shown that flood-stressed trees emit ethanol and are preferentially attacked by ambrosia beetles. Our goal was to develop a media (also called potting soil) moisture threshold as an integrated pest management (IPM) tactic and assess grower practices that lead to ambrosia beetle attacks. Flooded Cornus florida L., Cornus kousa Burg., and Magnolia grandiflora L. trees incurred more attacks than unflooded trees that were not attacked. To determine optimal media moisture levels, we grew flood-tolerant Acer rubrum L. and flood-intolerant C. florida in containers with 10, 30, 50, 70, or 90% media moisture. No flooded or unflooded A. rubrum were attacked. However, C. florida grown in 70 or 90% moisture were attacked and died, whereas trees at 30 and 50% moisture were not attacked. Thus, we suggest an upper moisture threshold of 50% when growing C. florida and other flood-intolerant trees. However, during peak ambrosia beetle flight activity in spring 2013 and 2014, we found that media moisture levels in commercial nurseries were often between 50 and 90%. Implementing a media moisture threshold, as a new IPM tool, could reduce ambrosia beetle attacks and the need for insecticide applications, which is currently the only available management tactic. Future research should focus on how changes in substrates, irrigation, and other practices could help growers meet this threshold. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Health-Related Quality of Life with Subcutaneous C1-Inhibitor for Prevention of Attacks of Hereditary Angioedema.

PubMed

Lumry, William R; Craig, Timothy; Zuraw, Bruce; Longhurst, Hilary; Baker, James; Li, H Henry; Bernstein, Jonathan A; Anderson, John; Riedl, Marc A; Manning, Michael E; Keith, Paul K; Levy, Donald S; Caballero, Teresa; Banerji, Aleena; Gower, Richard G; Farkas, Henriette; Lawo, John-Philip; Pragst, Ingo; Machnig, Thomas; Watson, Douglas J

2018-01-31

Hereditary angioedema with C1-inhibitor deficiency (C1-INH-HAE) impairs health-related quality of life (HRQoL). The objective of this study was to assess HRQoL outcomes in patients self-administering subcutaneous C1-INH (C1-INH[SC]; HAEGARDA) for routine prevention of HAE attacks. Post hoc analysis of data from the placebo-controlled, crossover phase III COMPACT study (Clinical Studies for Optimal Management of Preventing Angioedema with Low-Volume Subcutaneous C1-Inhibitor Replacement Therapy). Ninety patients with C1-INH-HAE were randomized to 1 of 4 treatment sequences: C1-INH(SC) 40 or 60 IU/kg twice weekly for 16 weeks, preceded or followed by 16 weeks of twice weekly placebo injections. All HAE attacks were treated with open-label on-demand treatment as necessary. HRQoL assessments at week 14 (last visit) included the European Quality of Life-5 Dimensions Questionnaire (EQ-5D-3L), the Hospital Anxiety and Depression Scale (HADS), the Work Productivity and Activity Impairment Questionnaire (WPAI), and the Treatment Satisfaction Questionnaire for Medication (TSQM). Compared with placebo (on-demand treatment alone), treatment with twice weekly C1-INH(SC) (both doses combined) was associated with better EQ-5D visual analog scale general health, less HADS anxiety, less WPAI presenteeism, work productivity loss, and activity impairment, and greater TSQM effectiveness and overall treatment satisfaction. More patients self-reported a "good/excellent" response during routine prevention with C1-INH(SC) compared with on-demand only (placebo prophylaxis) management. For each HRQoL measure, a greater proportion of patients had a clinically meaningful improvement during C1-INH(SC) treatment compared with placebo. In patients with frequent HAE attacks, a treatment strategy of routine prevention with self-administered twice weekly C1-INH(SC) had a greater impact on improving multiple HAE-related HRQoL impairments, most notably anxiety and work productivity, compared with on-demand treatment alone (placebo prophylaxis). Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Relational Aggression: A Different Kind of Bullying.

ERIC Educational Resources Information Center

Mullin-Rindler, Nancy

2003-01-01

Relational aggression is a form of bullying that includes both overt name-calling and verbal attacks as well as such indirect strategies as spreading gossip and rumors, manipulating friendships, or intentionally excluding or isolating someone. Educators must become more attuned and vigilant in their responses to it. Offers successful strategies.…

The Efficacy of Shared Reading with Teens.

ERIC Educational Resources Information Center

Hicks, Karen; Wadlington, Beth

An instructional strategy adapted the Big Book reading experience to the adolescent student to increase enthusiasm for reading, vocabulary development, and sound word attack and comprehension strategies. Criteria for choosing books to read aloud with teenagers include: (1) select well written books; (2) select books that reflect students'…

A Citadel under Siege: A Strategy against the Censor.

ERIC Educational Resources Information Center

North, William D.

1986-01-01

Identifies the tasks that the library administrator must complete if the collection is to successfully withstand censorship. Using an analogy of the construction, arming, and manning of a "citadel," a strategy is presented which is adaptable to the broadest range of attack on collection, acquisition, and dissemination policies of…

Beyond Iraq: The Lessons of a Hard Place

DTIC Science & Technology

2007-07-01

Hegemony or Survival, widely read since Venezuelan President Huga Chavez called attention to it in his UN General Assembly speech in the fall of 2006, Noam ... Chomsky makes a sport of attacking the 2002 National Security Strategy upon which the 2004 NMS is based. 39. 2006 National Security Strategy

Improving World Health: A Least Cost Strategy. Worldwatch Paper 59.

ERIC Educational Resources Information Center

Chandler, William U.

Least-cost health strategies designed to attack the world's leading causes of unnecessary death are explored. Section 1 emphasizes the value of primary health-care procedures--midwifery, maternal education on breastfeeding and weaning, vaccinations, oral rehydration of victims of diarrhea, and antibiotics against respiratory infections--in…

Security issues of Internet-based biometric authentication systems: risks of Man-in-the-Middle and BioPhishing on the example of BioWebAuth

NASA Astrophysics Data System (ADS)

Zeitz, Christian; Scheidat, Tobias; Dittmann, Jana; Vielhauer, Claus; González Agulla, Elisardo; Otero Muras, Enrique; García Mateo, Carmen; Alba Castro, José L.

2008-02-01

Beside the optimization of biometric error rates the overall security system performance in respect to intentional security attacks plays an important role for biometric enabled authentication schemes. As traditionally most user authentication schemes are knowledge and/or possession based, firstly in this paper we present a methodology for a security analysis of Internet-based biometric authentication systems by enhancing known methodologies such as the CERT attack-taxonomy with a more detailed view on the OSI-Model. Secondly as proof of concept, the guidelines extracted from this methodology are strictly applied to an open source Internet-based biometric authentication system (BioWebAuth). As case studies, two exemplary attacks, based on the found security leaks, are investigated and the attack performance is presented to show that during the biometric authentication schemes beside biometric error performance tuning also security issues need to be addressed. Finally, some design recommendations are given in order to ensure a minimum security level.

AVQS: attack route-based vulnerability quantification scheme for smart grid.

PubMed

Ko, Jongbin; Lim, Hyunwoo; Lee, Seokjun; Shon, Taeshik

2014-01-01

A smart grid is a large, consolidated electrical grid system that includes heterogeneous networks and systems. Based on the data, a smart grid system has a potential security threat in its network connectivity. To solve this problem, we develop and apply a novel scheme to measure the vulnerability in a smart grid domain. Vulnerability quantification can be the first step in security analysis because it can help prioritize the security problems. However, existing vulnerability quantification schemes are not suitable for smart grid because they do not consider network vulnerabilities. We propose a novel attack route-based vulnerability quantification scheme using a network vulnerability score and an end-to-end security score, depending on the specific smart grid network environment to calculate the vulnerability score for a particular attack route. To evaluate the proposed approach, we derive several attack scenarios from the advanced metering infrastructure domain. The experimental results of the proposed approach and the existing common vulnerability scoring system clearly show that we need to consider network connectivity for more optimized vulnerability quantification.

Coping strategies among adolescents: Israeli Jews and Arabs facing missile attacks.

PubMed

Braun-Lewensohn, Orna; Sagy, Shifra; Roth, Guy

2010-01-01

The study examined the use of coping strategies among Israeli Jewish and Arab adolescents who faced missile attacks during the Second Lebanon War. We further explored the role of ethnicity, gender and age in explaining psychological distress and the ways in which different coping strategies relate to health outcomes in the two ethnic groups. Data were gathered from 303 Israeli adolescents (231 Jews and 72 Arabs), 12-19 years old, who filled out self-reported questionnaires among which were demographics; Adolescent Coping Scale, Scale of Psychological Distress (SPD), state anxiety and state anger. Both Jewish and Arab adolescents mostly used "problem solving" coping strategies and reported relatively low levels of psychological distress. Similarities among Jews and Arabs were indicated in the use of "problem solving" coping strategies but not in the use of "reference to others"--and "non-productive" coping strategies. Significant but small effects were indicated for gender and interaction of ethnicity and age on "psychological distress." The coping strategies explained only 35% of the variance of stress reactions for the Jewish group but 51% for the Arab group. The results are discussed against the background of an interactionist approach, considering coping as a function of interaction between the stressful war event and the individual-cultural background.

Modeling Resources Allocation in Attacker-Defender Games with "Warm Up" CSF.

PubMed

Guan, Peiqiu; Zhuang, Jun

2016-04-01

Like many other engineering investments, the attacker's and defender's investments may have limited impact without initial capital to "warm up" the systems. This article studies such "warm up" effects on both the attack and defense equilibrium strategies in a sequential-move game model by developing a class of novel and more realistic contest success functions. We first solve a single-target attacker-defender game analytically and provide numerical solutions to a multiple-target case. We compare the results of the models with and without consideration of the investment "warm up" effects, and find that the defender would suffer higher expected damage, and either underestimate the attacker effort or waste defense investment if the defender falsely believes that no investment "warm up" effects exist. We illustrate the model results with real data, and compare the results of the models with and without consideration of the correlation between the "warm up" threshold and the investment effectiveness. Interestingly, we find that the defender is suggested to give up defending all the targets when the attack or the defense "warm up" thresholds are sufficiently high. This article provides new insights and suggestions on policy implications for homeland security resource allocation. © 2015 Society for Risk Analysis.

Secure Fusion Estimation for Bandwidth Constrained Cyber-Physical Systems Under Replay Attacks.

PubMed

Chen, Bo; Ho, Daniel W C; Hu, Guoqiang; Yu, Li; Bo Chen; Ho, Daniel W C; Guoqiang Hu; Li Yu; Chen, Bo; Ho, Daniel W C; Hu, Guoqiang; Yu, Li

2018-06-01

State estimation plays an essential role in the monitoring and supervision of cyber-physical systems (CPSs), and its importance has made the security and estimation performance a major concern. In this case, multisensor information fusion estimation (MIFE) provides an attractive alternative to study secure estimation problems because MIFE can potentially improve estimation accuracy and enhance reliability and robustness against attacks. From the perspective of the defender, the secure distributed Kalman fusion estimation problem is investigated in this paper for a class of CPSs under replay attacks, where each local estimate obtained by the sink node is transmitted to a remote fusion center through bandwidth constrained communication channels. A new mathematical model with compensation strategy is proposed to characterize the replay attacks and bandwidth constrains, and then a recursive distributed Kalman fusion estimator (DKFE) is designed in the linear minimum variance sense. According to different communication frameworks, two classes of data compression and compensation algorithms are developed such that the DKFEs can achieve the desired performance. Several attack-dependent and bandwidth-dependent conditions are derived such that the DKFEs are secure under replay attacks. An illustrative example is given to demonstrate the effectiveness of the proposed methods.

One-Year Outcomes After Minor Stroke or High-Risk Transient Ischemic Attack: Korean Multicenter Stroke Registry Analysis.

PubMed

Park, Hong-Kyun; Kim, Beom Joon; Han, Moon-Ku; Park, Jong-Moo; Kang, Kyusik; Lee, Soo Joo; Kim, Jae Guk; Cha, Jae-Kwan; Kim, Dae-Hyun; Nah, Hyun-Wook; Park, Tai Hwan; Park, Sang-Soon; Lee, Kyung Bok; Lee, Jun; Hong, Keun-Sik; Cho, Yong-Jin; Lee, Byung-Chul; Yu, Kyung-Ho; Oh, Mi-Sun; Kim, Joon-Tae; Choi, Kang-Ho; Kim, Dong-Eog; Ryu, Wi-Sun; Choi, Jay Chol; Johansson, Saga; Lee, Su Jin; Lee, Won Hee; Lee, Ji Sung; Lee, Juneyoung; Bae, Hee-Joon

2017-11-01

Patients with minor ischemic stroke or transient ischemic attack are at high risk of recurrent stroke and vascular events, which are potentially disabling or fatal. This study aimed to evaluate contemporary subsequent vascular event risk after minor ischemic stroke or transient ischemic attack in Korea. Patients with minor ischemic stroke or high-risk transient ischemic attack admitted within 7 days of symptom onset were identified from a Korean multicenter stroke registry database. We estimated 3-month and 1-year event rates of the primary outcome (composite of stroke recurrence, myocardial infarction, or all-cause death), stroke recurrence, a major vascular event (composite of stroke recurrence, myocardial infarction, or vascular death), and all-cause death and explored differences in clinical characteristics and event rates according to antithrombotic strategies at discharge. Of 9506 patients enrolled in this study, 93.8% underwent angiographic assessment and 72.7% underwent cardiac evaluations; 25.1% had symptomatic stenosis or occlusion of intracranial arteries. At discharge, 95.2% of patients received antithrombotics (antiplatelet polytherapy, 37.1%; anticoagulation, 15.3%) and 86.2% received statins. The 3-month cumulative event rate was 5.9% for the primary outcome, 4.3% for stroke recurrence, 4.6% for a major vascular event, and 2.0% for all-cause death. Corresponding values at 1 year were 9.3%, 6.1%, 6.7%, and 4.1%, respectively. Patients receiving nonaspirin antithrombotic strategies or no antithrombotic agent had higher baseline risk profiles and at least 1.5× higher event rates for clinical event outcomes than those with aspirin monotherapy. Contemporary secondary stroke prevention strategies based on thorough diagnostic evaluation may contribute to the low subsequent vascular event rates observed in real-world clinical practice in Korea. © 2017 American Heart Association, Inc.

Air Force Research Laboratory Resident Associateship Program Continuation

DTIC Science & Technology

2014-12-04

2011-7/17/2012 United States Received Veremyev, Alexander Fedorovich Pasiliao, Eduardo Lewis 8/1/2012-7/31/2013 Russia Sensors Directorate Aga...mass and damping on their modal characteristics. 5 Aerodynamic loads were estimated from the wind -tunnel test data, where the angle of attack of the... Wireless Networks; Throughput Optimization for Cognitive Radio Network with Slowly Varying Channels. 2 Capacity Optimization of MIMO Links with

Response to Nadler's Commentary on Arch and Craske's (2011) "Addressing Relapse in Cognitive Behavioral Therapy for Panic Disorder: Methods for Optimizing Long-Term Treatment Outcomes"

ERIC Educational Resources Information Center

Arch, Joanna J.; Craske, Michelle G.

2012-01-01

Nadler (this issue), in his commentary of our article, "Addressing Relapse in Cognitive Behavioral Therapy for Panic Disorder: Methods for Optimizing Long-Term Treatment Outcomes" (Arch & Craske, 2011), argues that we misrepresent the role of panic attacks within learning theory and overlook cognitive treatment targets. He presents several case…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Almajali, Anas; Rice, Eric; Viswanathan, Arun

This paper presents a systems analysis approach to characterizing the risk of a Smart Grid to a load-drop attack. A characterization of the risk is necessary for the design of detection and remediation strategies to address the consequences of such attacks. Using concepts from systems health management and system engineering, this work (a) first identifies metrics that can be used to generate constraints for security features, and (b) lays out an end-to-end integrated methodology using separate network and power simulations to assess system risk. We demonstrate our approach by performing a systems-style analysis of a load-drop attack implemented over themore » AMI subsystem and targeted at destabilizing the underlying power grid.« less

Insecurity of Detector-Device-Independent Quantum Key Distribution.

PubMed

Sajeed, Shihan; Huang, Anqi; Sun, Shihai; Xu, Feihu; Makarov, Vadim; Curty, Marcos

2016-12-16

Detector-device-independent quantum key distribution (DDI-QKD) held the promise of being robust to detector side channels, a major security loophole in quantum key distribution (QKD) implementations. In contrast to what has been claimed, however, we demonstrate that the security of DDI-QKD is not based on postselected entanglement, and we introduce various eavesdropping strategies that show that DDI-QKD is in fact insecure against detector side-channel attacks as well as against other attacks that exploit devices' imperfections of the receiver. Our attacks are valid even when the QKD apparatuses are built by the legitimate users of the system themselves, and thus, free of malicious modifications, which is a key assumption in DDI-QKD.

Lethal aggression in Pan is better explained by adaptive strategies than human impacts.

PubMed

Wilson, Michael L; Boesch, Christophe; Fruth, Barbara; Furuichi, Takeshi; Gilby, Ian C; Hashimoto, Chie; Hobaiter, Catherine L; Hohmann, Gottfried; Itoh, Noriko; Koops, Kathelijne; Lloyd, Julia N; Matsuzawa, Tetsuro; Mitani, John C; Mjungu, Deus C; Morgan, David; Muller, Martin N; Mundry, Roger; Nakamura, Michio; Pruetz, Jill; Pusey, Anne E; Riedel, Julia; Sanz, Crickette; Schel, Anne M; Simmons, Nicole; Waller, Michel; Watts, David P; White, Frances; Wittig, Roman M; Zuberbühler, Klaus; Wrangham, Richard W

2014-09-18

Observations of chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) provide valuable comparative data for understanding the significance of conspecific killing. Two kinds of hypothesis have been proposed. Lethal violence is sometimes concluded to be the result of adaptive strategies, such that killers ultimately gain fitness benefits by increasing their access to resources such as food or mates. Alternatively, it could be a non-adaptive result of human impacts, such as habitat change or food provisioning. To discriminate between these hypotheses we compiled information from 18 chimpanzee communities and 4 bonobo communities studied over five decades. Our data include 152 killings (n = 58 observed, 41 inferred, and 53 suspected killings) by chimpanzees in 15 communities and one suspected killing by bonobos. We found that males were the most frequent attackers (92% of participants) and victims (73%); most killings (66%) involved intercommunity attacks; and attackers greatly outnumbered their victims (median 8:1 ratio). Variation in killing rates was unrelated to measures of human impacts. Our results are compatible with previously proposed adaptive explanations for killing by chimpanzees, whereas the human impact hypothesis is not supported.

Game Theory Meets Wireless Sensor Networks Security Requirements and Threats Mitigation: A Survey

PubMed Central

Abdalzaher, Mohamed S.; Seddik, Karim; Elsabrouty, Maha; Muta, Osamu; Furukawa, Hiroshi; Abdel-Rahman, Adel

2016-01-01

We present a study of using game theory for protecting wireless sensor networks (WSNs) from selfish behavior or malicious nodes. Due to scalability, low complexity and disseminated nature of WSNs, malicious attacks can be modeled effectively using game theory. In this study, we survey the different game-theoretic defense strategies for WSNs. We present a taxonomy of the game theory approaches based on the nature of the attack, whether it is caused by an external attacker or it is the result of an internal node acting selfishly or maliciously. We also present a general trust model using game theory for decision making. We, finally, identify the significant role of evolutionary games for WSNs security against intelligent attacks; then, we list several prospect applications of game theory to enhance the data trustworthiness and node cooperation in different WSNs. PMID:27367700

Violent extremist group ecologies under stress

PubMed Central

Cebrian, Manuel; Torres, Manuel R.; Huerta, Ramon; Fowler, James H.

2013-01-01

Violent extremist groups are currently making intensive use of Internet fora for recruitment to terrorism. These fora are under constant scrutiny by security agencies, private vigilante groups, and hackers, who sometimes shut them down with cybernetic attacks. However, there is a lack of experimental and formal understanding of the recruitment dynamics of online extremist fora and the effect of strategies to control them. Here, we utilize data on ten extremist fora that we collected for four years to develop a data-driven mathematical model that is the first attempt to measure whether (and how) these external attacks induce extremist fora to self-regulate. The results suggest that an increase in the number of groups targeted for attack causes an exponential increase in the cost of enforcement and an exponential decrease in its effectiveness. Thus, a policy to occasionally attack large groups can be very efficient for limiting violent output from these fora. PMID:23536118

Violent extremist group ecologies under stress.

PubMed

Cebrian, Manuel; Torres, Manuel R; Huerta, Ramon; Fowler, James H

2013-01-01

Violent extremist groups are currently making intensive use of Internet fora for recruitment to terrorism. These fora are under constant scrutiny by security agencies, private vigilante groups, and hackers, who sometimes shut them down with cybernetic attacks. However, there is a lack of experimental and formal understanding of the recruitment dynamics of online extremist fora and the effect of strategies to control them. Here, we utilize data on ten extremist fora that we collected for four years to develop a data-driven mathematical model that is the first attempt to measure whether (and how) these external attacks induce extremist fora to self-regulate. The results suggest that an increase in the number of groups targeted for attack causes an exponential increase in the cost of enforcement and an exponential decrease in its effectiveness. Thus, a policy to occasionally attack large groups can be very efficient for limiting violent output from these fora.

Air data system optimization using a genetic algorithm

NASA Technical Reports Server (NTRS)

Deshpande, Samir M.; Kumar, Renjith R.; Seywald, Hans; Siemers, Paul M., III

1992-01-01

An optimization method for flush-orifice air data system design has been developed using the Genetic Algorithm approach. The optimization of the orifice array minimizes the effect of normally distributed random noise in the pressure readings on the calculation of air data parameters, namely, angle of attack, sideslip angle and freestream dynamic pressure. The optimization method is applied to the design of Pressure Distribution/Air Data System experiment (PD/ADS) proposed for inclusion in the Aeroassist Flight Experiment (AFE). Results obtained by the Genetic Algorithm method are compared to the results obtained by conventional gradient search method.

Automation of On-Board Flightpath Management

NASA Technical Reports Server (NTRS)

Erzberger, H.

1981-01-01

The status of concepts and techniques for the design of onboard flight path management systems is reviewed. Such systems are designed to increase flight efficiency and safety by automating the optimization of flight procedures onboard aircraft. After a brief review of the origins and functions of such systems, two complementary methods are described for attacking the key design problem, namely, the synthesis of efficient trajectories. One method optimizes en route, the other optimizes terminal area flight; both methods are rooted in optimal control theory. Simulation and flight test results are reviewed to illustrate the potential of these systems for fuel and cost savings.

Hypergame theory applied to cyber attack and defense

NASA Astrophysics Data System (ADS)

House, James Thomas; Cybenko, George

2010-04-01

This work concerns cyber attack and defense in the context of game theory--specifically hypergame theory. Hypergame theory extends classical game theory with the ability to deal with differences in players' expertise, differences in their understanding of game rules, misperceptions, and so forth. Each of these different sub-scenarios, or subgames, is associated with a probability--representing the likelihood that the given subgame is truly "in play" at a given moment. In order to form an optimal attack or defense policy, these probabilities must be learned if they're not known a-priori. We present hidden Markov model and maximum entropy approaches for accurately learning these probabilities through multiple iterations of both normal and modified game play. We also give a widely-applicable approach for the analysis of cases where an opponent is aware that he is being studied, and intentionally plays to spoil the process of learning and thereby obfuscate his attributes. These are considered in the context of a generic, abstract cyber attack example. We demonstrate that machine learning efficacy can be heavily dependent on the goals and styles of participant behavior. To this end detailed simulation results under various combinations of attacker and defender behaviors are presented and analyzed.

Egypt: Security, Political, and Islamist Challenges

DTIC Science & Technology

2007-09-01

vehicles used had been traced to Greater Cairo, and that Mubarak was withholding critique of al-Qa’ida in these attacks.121 After the attacks, 12,000...American film producers shot here], they don’t care about us . And if we weren’t cheap labor or better than the [topographical] maps, neither the...military strategy with emphasis on geostrategic analysis. The mission of SSI is to use independent analysis to conduct strategic studies that develop policy

Human-Wildlife Conflicts in Nepal: Patterns of Human Fatalities and Injuries Caused by Large Mammals.

PubMed

Acharya, Krishna Prasad; Paudel, Prakash Kumar; Neupane, Prem Raj; Köhl, Michael

2016-01-01

Injury and death from wildlife attacks often result in people feeling violent resentment and hostility against the wildlife involved and, therefore, may undermine public support for conservation. Although Nepal, with rich biodiversity, is doing well in its conservation efforts, human-wildlife conflicts have been a major challenge in recent years. The lack of detailed information on the spatial and temporal patterns of human-wildlife conflicts at the national level impedes the development of effective conflict mitigation plans. We examined patterns of human injury and death caused by large mammals using data from attack events and their spatiotemporal dimensions collected from a national survey of data available in Nepal over five years (2010-2014). Data were analyzed using logistic regression and chi-square or Fisher's exact tests. The results show that Asiatic elephants and common leopards are most commonly involved in attacks on people in terms of attack frequency and fatalities. Although one-horned rhinoceros and bears had a higher frequency of attacks than Bengal tigers, tigers caused more fatalities than each of these two species. Attacks by elephants peaked in winter and most frequently occurred outside protected areas in human settlements. Leopard attacks occurred almost entirely outside protected areas, and a significantly greater number of attacks occurred in human settlements. Attacks by one-horned rhinoceros and tigers were higher in the winter, mainly in forests inside protected areas; similarly, attacks by bears occurred mostly within protected areas. We found that human settlements are increasingly becoming conflict hotspots, with burgeoning incidents involving elephants and leopards. We conclude that species-specific conservation strategies are urgently needed, particularly for leopards and elephants. The implications of our findings for minimizing conflicts and conserving these imperiled species are discussed.

Human-Wildlife Conflicts in Nepal: Patterns of Human Fatalities and Injuries Caused by Large Mammals

PubMed Central

Acharya, Krishna Prasad; Paudel, Prakash Kumar; Neupane, Prem Raj; Köhl, Michael

2016-01-01

Injury and death from wildlife attacks often result in people feeling violent resentment and hostility against the wildlife involved and, therefore, may undermine public support for conservation. Although Nepal, with rich biodiversity, is doing well in its conservation efforts, human-wildlife conflicts have been a major challenge in recent years. The lack of detailed information on the spatial and temporal patterns of human-wildlife conflicts at the national level impedes the development of effective conflict mitigation plans. We examined patterns of human injury and death caused by large mammals using data from attack events and their spatiotemporal dimensions collected from a national survey of data available in Nepal over five years (2010–2014). Data were analyzed using logistic regression and chi-square or Fisher's exact tests. The results show that Asiatic elephants and common leopards are most commonly involved in attacks on people in terms of attack frequency and fatalities. Although one-horned rhinoceros and bears had a higher frequency of attacks than Bengal tigers, tigers caused more fatalities than each of these two species. Attacks by elephants peaked in winter and most frequently occurred outside protected areas in human settlements. Leopard attacks occurred almost entirely outside protected areas, and a significantly greater number of attacks occurred in human settlements. Attacks by one-horned rhinoceros and tigers were higher in the winter, mainly in forests inside protected areas; similarly, attacks by bears occurred mostly within protected areas. We found that human settlements are increasingly becoming conflict hotspots, with burgeoning incidents involving elephants and leopards. We conclude that species-specific conservation strategies are urgently needed, particularly for leopards and elephants. The implications of our findings for minimizing conflicts and conserving these imperiled species are discussed. PMID:27612174

Mass casualty response in the 2008 Mumbai terrorist attacks.

PubMed

Roy, Nobhojit; Kapil, Vikas; Subbarao, Italo; Ashkenazi, Isaac

2011-12-01

The November 26-29, 2008, terrorist attacks on Mumbai were unique in its international media attention, multiple strategies of attack, and the disproportionate national fear they triggered. Everyone was a target: random members of the general population, iconic targets, and foreigners alike were under attack by the terrorists. A retrospective, descriptive study of the distribution of terror victims to various city hospitals, critical radius, surge capacity, and the nature of specialized medical interventions was gathered through police, legal reports, and interviews with key informants. Among the 172 killed and 304 injured people, about four-fifths were men (average age, 33 years) and 12% were foreign nationals. The case-fatality ratio for this event was 2.75:1, and the mortality rate among those who were critically injured was 12%. A total of 38.5% of patients arriving at the hospitals required major surgical intervention. Emergency surgical operations were mainly orthopedic (external fixation for compound fractures) and general surgical interventions (abdominal explorations for penetrating bullet/shrapnel injuries). The use of heavy-duty automatic weapons, explosives, hostages, and arson in these terrorist attacks alerts us to new challenges to medical counterterrorism response. The need for building central medical control for a coordinated response and for strengthening public hospital capacity are lessons learned for future attacks. These particular terrorist attacks had global consequences, in terms of increased security checks and alerts for and fears of further similar "Mumbai-style" attacks. The resilience of the citizens of Mumbai is a critical measure of the long-term effects of terror attacks.

Numerical Investigations of an Optimized Airfoil with a Rotary Cylinder

NASA Astrophysics Data System (ADS)

Gada, Komal; Rahai, Hamid

2015-11-01

Numerical Investigations of an optimized thin airfoil with a rotary cylinder as a control device for reducing separation and improving lift to drag ratio have been performed. Our previous investigations have used geometrical optimization for development of an optimized airfoil with increased torque for applications in a vertical axis wind turbine. The improved performance was due to contributions of lift to torque at low angles of attack. The current investigations have been focused on using the optimized airfoil for micro-uav applications with an active flow control device, a rotary cylinder, to further control flow separation, especially during wind gust conditions. The airfoil has a chord length of 19.66 cm and a width of 25 cm with 0.254 cm thickness. Previous investigations have shown flow separation at approximately 85% chord length at moderate angles of attack. Thus the rotary cylinder with a 0.254 cm diameter was placed slightly downstream of the location of flow separation. The free stream mean velocity was 10 m/sec. and investigations have been performed at different cylinder's rotations with corresponding tangential velocities higher than, equal to and less than the free stream velocity. Results have shown more than 10% improvement in lift to drag ratio when the tangential velocity is near the free stream mean velocity. Graduate Assistant, Center for Energy and Environmental Research and Services (CEERS), College of Engineering, California State University, Long Beach.

Anthrax vaccination strategies

PubMed Central

Cybulski, Robert J.; Sanz, Patrick; O'Brien, Alison D.

2009-01-01

The biological attack conducted through the U.S. postal system in 2001 broadened the threat posed by anthrax from one pertinent mainly to soldiers on the battlefield to one understood to exist throughout our society. The expansion of the threatened population placed greater emphasis on the reexamination of how we vaccinate against Bacillus anthracis. The currently-licensed Anthrax Vaccine, Adsorbed (AVA) and Anthrax Vaccine, Precipitated (AVP) are capable of generating a protective immune response but are hampered by shortcomings that make their widespread use undesirable or infeasible. Efforts to gain U.S. Food and Drug Administration (FDA) approval for licensure of a second generation recombinant protective antigen (rPA)-based anthrax vaccine are ongoing. However, this vaccine's reliance on the generation of a humoral immune response against a single virulence factor has led a number of scientists to conclude that the vaccine is likely not the final solution to optimal anthrax vaccine design. Other vaccine approaches, which seek a more comprehensive immune response targeted at multiple components of the B. anthracis organism, are under active investigation. This review seeks to summarize work that has been done to build on the current PA-based vaccine methodology and to evaluate the search for future anthrax prophylaxis strategies. PMID:19729034

Adversarial Feature Selection Against Evasion Attacks.

PubMed

Zhang, Fei; Chan, Patrick P K; Biggio, Battista; Yeung, Daniel S; Roli, Fabio

2016-03-01

Pattern recognition and machine learning techniques have been increasingly adopted in adversarial settings such as spam, intrusion, and malware detection, although their security against well-crafted attacks that aim to evade detection by manipulating data at test time has not yet been thoroughly assessed. While previous work has been mainly focused on devising adversary-aware classification algorithms to counter evasion attempts, only few authors have considered the impact of using reduced feature sets on classifier security against the same attacks. An interesting, preliminary result is that classifier security to evasion may be even worsened by the application of feature selection. In this paper, we provide a more detailed investigation of this aspect, shedding some light on the security properties of feature selection against evasion attacks. Inspired by previous work on adversary-aware classifiers, we propose a novel adversary-aware feature selection model that can improve classifier security against evasion attacks, by incorporating specific assumptions on the adversary's data manipulation strategy. We focus on an efficient, wrapper-based implementation of our approach, and experimentally validate its soundness on different application examples, including spam and malware detection.

Contextual and Personal Predictors of Adaptive Outcomes under Terror Attack: The Case of Israeli Adolescents

ERIC Educational Resources Information Center

Zeidner, Moshe

2005-01-01

This paper explores individual differences in perceptions of political violence, strategies for coping with violence, and adaptive outcomes. Data on political violence stress, personal variables, coping strategies, and stress reactions were gathered on a sample of 227 Israeli adolescents in Haifa and Northern Israel confronted with a prolonged…

10 Ways to Find More Time

ERIC Educational Resources Information Center

Hitch, Chris

2008-01-01

There are two ways to avoid time-crunch panic attacks: work smarter and delegate wisely. In this article, the author provides a list of some strategies and tactics he has used to help more than 500 school executives in North Carolina work smarter, delegate more effectively and become more effective instructional leaders. These strategies fall into…

Administrative Challenges and Response Strategies to the Job Performance of Marketing Department Chairs.

ERIC Educational Resources Information Center

Dyer, Beverly G.; Miller, Michael T.

This study reports on the job challenges and corresponding response strategies that department chairs at graduate and undergraduate colleges and universities encounter and rely upon. Literature and research related to marketing department chairs, marketing education, and marketing majors indicates that business schools have come under attack by…

Physical-enhanced secure strategy in an OFDM-PON.

PubMed

Zhang, Lijia; Xin, Xiangjun; Liu, Bo; Yu, Jianjun

2012-01-30

The physical layer of optical access network is vulnerable to various attacks. As the dramatic increase of users and network capacity, the issue of physical-layer security becomes more and more important. This paper proposes a physical-enhanced secure strategy for orthogonal frequency division multiplexing passive optical network (OFDM-PON) by employing frequency domain chaos scrambling. The Logistic map is adopted for the chaos mapping. The chaos scrambling strategy can dynamically allocate the scrambling matrices for different OFDM frames according to the initial condition, which enhance the confidentiality of the physical layer. A mathematical model of this secure system is derived firstly, which achieves a secure transmission at physical layer in OFDM-PON. The results from experimental implementation using Logistic mapped chaos scrambling are also given to further demonstrate the efficiency of this secure strategy. An 10.125 Gb/s 64QAM-OFDM data with Logistic mapped chaos scrambling are successfully transmitted over 25-km single mode fiber (SMF), and the experimental results show that proposed security scheme can protect the system from eavesdropper and attacker, while keep a good performance for the legal ONU.

A Game-Theoretical Model to Improve Process Plant Protection from Terrorist Attacks.

PubMed

Zhang, Laobing; Reniers, Genserik

2016-12-01

The New York City 9/11 terrorist attacks urged people from academia as well as from industry to pay more attention to operational security research. The required focus in this type of research is human intention. Unlike safety-related accidents, security-related accidents have a deliberate nature, and one has to face intelligent adversaries with characteristics that traditional probabilistic risk assessment techniques are not capable of dealing with. In recent years, the mathematical tool of game theory, being capable to handle intelligent players, has been used in a variety of ways in terrorism risk assessment. In this article, we analyze the general intrusion detection system in process plants, and propose a game-theoretical model for security management in such plants. Players in our model are assumed to be rational and they play the game with complete information. Both the pure strategy and the mixed strategy solutions are explored and explained. We illustrate our model by an illustrative case, and find that in our case, no pure strategy but, instead, a mixed strategy Nash equilibrium exists. © 2016 Society for Risk Analysis.

A Methodological Approach for Assessing Amplified Reflection Distributed Denial of Service on the Internet of Things

PubMed Central

Costa Gondim, João José; de Oliveira Albuquerque, Robson; Clayton Alves Nascimento, Anderson; García Villalba, Luis Javier; Kim, Tai-Hoon

2016-01-01

Concerns about security on Internet of Things (IoT) cover data privacy and integrity, access control, and availability. IoT abuse in distributed denial of service attacks is a major issue, as typical IoT devices’ limited computing, communications, and power resources are prioritized in implementing functionality rather than security features. Incidents involving attacks have been reported, but without clear characterization and evaluation of threats and impacts. The main purpose of this work is to methodically assess the possible impacts of a specific class–amplified reflection distributed denial of service attacks (AR-DDoS)–against IoT. The novel approach used to empirically examine the threat represented by running the attack over a controlled environment, with IoT devices, considered the perspective of an attacker. The methodology used in tests includes that perspective, and actively prospects vulnerabilities in computer systems. This methodology defines standardized procedures for tool-independent vulnerability assessment based on strategy, and the decision flows during execution of penetration tests (pentests). After validation in different scenarios, the methodology was applied in amplified reflection distributed denial of service (AR-DDoS) attack threat assessment. Results show that, according to attack intensity, AR-DDoS saturates reflector infrastructure. Therefore, concerns about AR-DDoS are founded, but expected impact on abused IoT infrastructure and devices will be possibly as hard as on final victims. PMID:27827931

A Methodological Approach for Assessing Amplified Reflection Distributed Denial of Service on the Internet of Things.

PubMed

Costa Gondim, João José; de Oliveira Albuquerque, Robson; Clayton Alves Nascimento, Anderson; García Villalba, Luis Javier; Kim, Tai-Hoon

2016-11-04

Concerns about security on Internet of Things (IoT) cover data privacy and integrity, access control, and availability. IoT abuse in distributed denial of service attacks is a major issue, as typical IoT devices' limited computing, communications, and power resources are prioritized in implementing functionality rather than security features. Incidents involving attacks have been reported, but without clear characterization and evaluation of threats and impacts. The main purpose of this work is to methodically assess the possible impacts of a specific class-amplified reflection distributed denial of service attacks (AR-DDoS)-against IoT. The novel approach used to empirically examine the threat represented by running the attack over a controlled environment, with IoT devices, considered the perspective of an attacker. The methodology used in tests includes that perspective, and actively prospects vulnerabilities in computer systems. This methodology defines standardized procedures for tool-independent vulnerability assessment based on strategy, and the decision flows during execution of penetration tests (pentests). After validation in different scenarios, the methodology was applied in amplified reflection distributed denial of service (AR-DDoS) attack threat assessment. Results show that, according to attack intensity, AR-DDoS saturates reflector infrastructure. Therefore, concerns about AR-DDoS are founded, but expected impact on abused IoT infrastructure and devices will be possibly as hard as on final victims.

Genetics algorithm optimization of DWT-DCT based image Watermarking

NASA Astrophysics Data System (ADS)

Budiman, Gelar; Novamizanti, Ledya; Iwut, Iwan

2017-01-01

Data hiding in an image content is mandatory for setting the ownership of the image. Two dimensions discrete wavelet transform (DWT) and discrete cosine transform (DCT) are proposed as transform method in this paper. First, the host image in RGB color space is converted to selected color space. We also can select the layer where the watermark is embedded. Next, 2D-DWT transforms the selected layer obtaining 4 subband. We select only one subband. And then block-based 2D-DCT transforms the selected subband. Binary-based watermark is embedded on the AC coefficients of each block after zigzag movement and range based pixel selection. Delta parameter replacing pixels in each range represents embedded bit. +Delta represents bit “1” and -delta represents bit “0”. Several parameters to be optimized by Genetics Algorithm (GA) are selected color space, layer, selected subband of DWT decomposition, block size, embedding range, and delta. The result of simulation performs that GA is able to determine the exact parameters obtaining optimum imperceptibility and robustness, in any watermarked image condition, either it is not attacked or attacked. DWT process in DCT based image watermarking optimized by GA has improved the performance of image watermarking. By five attacks: JPEG 50%, resize 50%, histogram equalization, salt-pepper and additive noise with variance 0.01, robustness in the proposed method has reached perfect watermark quality with BER=0. And the watermarked image quality by PSNR parameter is also increased about 5 dB than the watermarked image quality from previous method.

Exposure‐Response Model of Subcutaneous C1‐Inhibitor Concentrate to Estimate the Risk of Attacks in Patients With Hereditary Angioedema

PubMed Central

Tortorici, Michael A.; Pawaskar, Dipti; Pragst, Ingo; Machnig, Thomas; Hutmacher, Matthew; Zuraw, Bruce; Cicardi, Marco; Craig, Timothy; Longhurst, Hilary; Sidhu, Jagdev

2018-01-01

Subcutaneous C1‐inhibitor (HAEGARDA, CSL Behring), is a US Food and Drug Administration (FDA)‐approved, highly concentrated formulation of a plasma‐derived C1‐esterase inhibitor (C1‐INH), which, in the phase III Clinical Studies for Optimal Management in Preventing Angioedema with Low‐Volume Subcutaneous C1‐inhibitor Replacement Therapy (COMPACT) trial, reduced the incidence of hereditary angioedema (HAE) attacks when given prophylactically. Data from the COMPACT trial were used to develop a repeated time‐to‐event model to characterize the timing and frequency of HAE attacks as a function of C1‐INH activity, and then develop an exposure–response model to assess the relationship between C1‐INH functional activity levels (C1‐INH(f)) and the risk of an attack. The C1‐INH(f) values of 33.1%, 40.3%, and 63.1% were predicted to correspond with 50%, 70%, and 90% reductions in the HAE attack risk, respectively, relative to no therapy. Based on trough C1‐INH(f) values for the 40 IU/kg (40.2%) and 60 IU/kg (48.0%) C1‐INH (SC) doses, the model predicted that 50% and 67% of the population, respectively, would see at least a 70% decrease in the risk of an attack. PMID:29316335

Air and Space Power Journal. Volume 29, Number 4. July-August 2015

DTIC Science & Technology

2015-08-01

Afghanistan, and Pakistan. It is incredibly difficult to prevent these attacks when the most explicit strategies are reactive ex post facto military...Editor, Strategic Studies Quarterly Air Force Research Institute Dr. Grant T. Hammond USAF Center for Strategy and Technology Dr. Dale L. Hayden Air Force...of War Studies at King’s College London, researches nonproliferation, terrorism, and US security policy. He observes that deterrence strategies

Oscillations in interconnected complex networks under intentional attack

NASA Astrophysics Data System (ADS)

Zhang, Wen-Ping; Xia, Yongxiang; Tan, Fei

2016-01-01

Many real-world networks are interconnected with each other. In this paper, we study the traffic dynamics in interconnected complex networks under an intentional attack. We find that with the shortest time delay routing strategy, the traffic dynamics can show the stable state, periodic, quasi-periodic and chaotic oscillations, when the capacity redundancy parameter changes. Moreover, compared with isolated complex networks, oscillations always take place in interconnected networks more easily. Thirdly, in interconnected networks, oscillations are affected strongly by the coupling probability and coupling preference.

Using Physical Models for Anomaly Detection in Control Systems

NASA Astrophysics Data System (ADS)

Svendsen, Nils; Wolthusen, Stephen

Supervisory control and data acquisition (SCADA) systems are increasingly used to operate critical infrastructure assets. However, the inclusion of advanced information technology and communications components and elaborate control strategies in SCADA systems increase the threat surface for external and subversion-type attacks. The problems are exacerbated by site-specific properties of SCADA environments that make subversion detection impractical; and by sensor noise and feedback characteristics that degrade conventional anomaly detection systems. Moreover, potential attack mechanisms are ill-defined and may include both physical and logical aspects.

'I was in control of it from the start': A qualitative study of men's experiences of positive adjustment following a heart attack.

PubMed

Smith, Fran; Banwell, Elizabeth; Rakhit, Roby

2017-09-01

A qualitative design was used to explore the experience of positive adjustment following a heart attack. Ten men attending a cardiac rehabilitation programme completed in-depth semi-structured interviews. An overarching theme: 'I was in control of it from the start' emerged with six subthemes, relating to intrapersonal and interpersonal factors and processes. The subthemes reflected the importance of identifying controllable versus non-controllable factors and employing adaptive coping strategies.

Proceedings of Seminar on Air Antitank Warfare Held at Springfield, Virginia on 25-26 May 1978

DTIC Science & Technology

1979-05-01

there is strategy . You have to get inside your adversary’s organization—learn his strengths, weaknesses, movement, and intentions. In other words...doing it maybe on a larger scale instead of down at the battalion or platoon levels . Finally, our third basis of attack is army. You should still do...all these things at the army level so that you can literally shatter them and pull them apart. Finally he brings up the notion of attacking cities

Pre-systemic metabolism of orally administered drugs and strategies to overcome it.

PubMed

Pereira de Sousa, Irene; Bernkop-Schnürch, Andreas

2014-10-28

The oral bioavailability of numerous drugs is not only limited by poor solubility and/or poor membrane permeability as addressed by the biopharmaceutical classification system (BCS) but also by a pre-systemic metabolism taking place to a high extent in the intestine. Enzymes responsible for metabolic reactions in the intestine include cytochromes P450 (CYP450), transferases, peptidases and proteases. Furthermore, in the gut nucleases, lipases as well as glycosidases influence the metabolic pathway of drugs and nutrients. A crucial role is also played by the intestinal microflora able to metabolize a wide broad of pharmaceutical compounds. Strategies to provide a protective effect towards an intestinal pre-systemic metabolism are based on the co-administration of enzyme inhibitor being optimally immobilized on unabsorbable and undegradable polymeric excipients in order to keep them concentrated there where an inhibitory effect is needed. Furthermore, certain polymeric excipients such as polyacrylates exhibit per se enzyme inhibitory properties. In addition, by incorporating drugs in cyclodextrines, in self-emulsifying drug delivery systems (SEDDS) or liposomes a protective effect towards an intestinal enzymatic attack can be achieved. Being aware of the important role of this pre-systemic metabolism by integrating it in the BCS as third dimension and keeping strategies to overcome this enzymatic barrier in mind, the therapeutic efficacy of many orally given drugs can certainly be substantially improved. Copyright © 2014 Elsevier B.V. All rights reserved.

Model-Based Comprehensive Analysis of School Closure Policies for Mitigating Influenza Epidemics and Pandemics

PubMed Central

Fumanelli, Laura; Ajelli, Marco; Merler, Stefano; Ferguson, Neil M.; Cauchemez, Simon

2016-01-01

School closure policies are among the non-pharmaceutical measures taken into consideration to mitigate influenza epidemics and pandemics spread. However, a systematic review of the effectiveness of alternative closure policies has yet to emerge. Here we perform a model-based analysis of four types of school closure, ranging from the nationwide closure of all schools at the same time to reactive gradual closure, starting from class-by-class, then grades and finally the whole school. We consider policies based on triggers that are feasible to monitor, such as school absenteeism and national ILI surveillance system. We found that, under specific constraints on the average number of weeks lost per student, reactive school-by-school, gradual, and county-wide closure give comparable outcomes in terms of optimal infection attack rate reduction, peak incidence reduction or peak delay. Optimal implementations generally require short closures of one week each; this duration is long enough to break the transmission chain without leading to unnecessarily long periods of class interruption. Moreover, we found that gradual and county closures may be slightly more easily applicable in practice as they are less sensitive to the value of the excess absenteeism threshold triggering the start of the intervention. These findings suggest that policy makers could consider school closure policies more diffusely as response strategy to influenza epidemics and pandemics, and the fact that some countries already have some experience of gradual or regional closures for seasonal influenza outbreaks demonstrates that logistic and feasibility challenges of school closure strategies can be to some extent overcome. PMID:26796333

Model-Based Comprehensive Analysis of School Closure Policies for Mitigating Influenza Epidemics and Pandemics.

PubMed

Fumanelli, Laura; Ajelli, Marco; Merler, Stefano; Ferguson, Neil M; Cauchemez, Simon

2016-01-01

School closure policies are among the non-pharmaceutical measures taken into consideration to mitigate influenza epidemics and pandemics spread. However, a systematic review of the effectiveness of alternative closure policies has yet to emerge. Here we perform a model-based analysis of four types of school closure, ranging from the nationwide closure of all schools at the same time to reactive gradual closure, starting from class-by-class, then grades and finally the whole school. We consider policies based on triggers that are feasible to monitor, such as school absenteeism and national ILI surveillance system. We found that, under specific constraints on the average number of weeks lost per student, reactive school-by-school, gradual, and county-wide closure give comparable outcomes in terms of optimal infection attack rate reduction, peak incidence reduction or peak delay. Optimal implementations generally require short closures of one week each; this duration is long enough to break the transmission chain without leading to unnecessarily long periods of class interruption. Moreover, we found that gradual and county closures may be slightly more easily applicable in practice as they are less sensitive to the value of the excess absenteeism threshold triggering the start of the intervention. These findings suggest that policy makers could consider school closure policies more diffusely as response strategy to influenza epidemics and pandemics, and the fact that some countries already have some experience of gradual or regional closures for seasonal influenza outbreaks demonstrates that logistic and feasibility challenges of school closure strategies can be to some extent overcome.

Towards improved migraine management: Determining potential trigger factors in individual patients.

PubMed

Peris, Francesc; Donoghue, Stephen; Torres, Ferran; Mian, Alec; Wöber, Christian

2017-04-01

Background Certain chronic diseases such as migraine result in episodic, debilitating attacks for which neither cause nor timing is well understood. Historically, possible triggers were identified through analysis of aggregated data from populations of patients. However, triggers common in populations may not be wholly responsible for an individual's attacks. To explore this hypothesis we developed a method to identify individual 'potential trigger' profiles and analysed the degree of inter-individual variation. Methods We applied N = 1 statistical analysis to a 326-migraine-patient database from a study in which patients used paper-based diaries for 90 days to track 33 factors (potential triggers or premonitory symptoms) associated with their migraine attacks. For each patient, univariate associations between factors and migraine events were analysed using Cox proportional hazards models. Results We generated individual factor-attack association profiles for 87% of the patients. The average number of factors associated with attacks was four per patient: Factor profiles were highly individual and were unique in 85% of patients with at least one identified association. Conclusion Accurate identification of individual factor-attack profiles is a prerequisite for testing which are true triggers and for development of trigger avoidance or desensitisation strategies. Our methodology represents a necessary development toward this goal.

Norms in Conflict: Statecraft, Preventive Force, and Counter Proliferation

DTIC Science & Technology

2016-12-01

power. Finally, the ethical character of norms offers a framework for the attacking state to justify its actions to the international community ...national identity, sanctions, and ethics play in counter-proliferation strategies. Finally, it concludes by offering policy recommendations for...role that national identity, sanctions, and ethics play in counter-proliferation strategies. Finally, it concludes by offering policy

Optimal Control of Airfoil Flow Separation using Fluidic Excitation

NASA Astrophysics Data System (ADS)

Shahrabi, Arireza F.

This thesis deals with the control of flow separation around a symmetric airfoils with the aid of multiple synthetic jet actuators (SJAs). CFD simulation methods have been implemented to uncover the flow separation regimes and associated properties such as frequencies and momentum ratio. In the first part of the study, the SJA was studied thoroughly. Large Eddy Simulations (LES) were performed for one individual cavity; the time history of SJA of the outlet velocity profile and the net momentum imparted to the flow were analyzed. The studied SJA is asymmetrical and operates with the aid of a piezoelectric (PZT) ceramic circular plate actuator. A three-dimensional mesh for the computational domain of the SJA and the surrounding volume was developed and was used to evaluate the details of the airflow conditions inside the SJA as well as at the outlet. The vibration of the PZT ceramic actuator was used as a boundary condition in the computational model to drive the SJA. Particular attention was given to developing a predictive model of the SJA outlet velocity. Results showed that the SJA velocity output is correlated to the PZT ceramic plate vibration, especially for the first frequency mode. SJAs are a particular class of zero net mass flux (ZNMF) fluidic devices with net imparted momentum to the flow. The net momentum imparted to the flow in the separated region is such that positive enhancement during AFC operations is achieved. Flows around the NACA 0015 airfoil were simulated for a range of operating conditions. Attention was given to the active open and closed loop control solutions for an airfoil with SJA at different angles of attack and flap angles. A large number of simulations using RANS & LES models were performed to study the effects of the momentum ratio (Cμ) in the range of 0 to 11% and of the non-dimensional frequency, F+, in the range of 0 to 2 for the control of flow separation at a practical angle of attack and flap angle. The optimum value of Cμ as well as F+ were evaluated and discussed. The computational model predictions showed good agreement with the experimental data. It was observed that different angles of attack and flap angles have different requirements for the minimum value of the momentum coefficient, Cμ, in order for the SJA to be effective for control of separation. It was also found that the variation of F + noticeably affects the lift and drag forces acting on the airfoil. The optimum values of parameters during open loop control simulations have been applied in order to introduce the optimal open loop control outcome. An innovative approach has been implemented to formulate optimal frequencies and momentum ratios of vortex shedding which depends on angle of attack and static pressure of the separation zone in the upper chord. Optimal open loop results have been compared with the optimal closed loop results. Cumulative case studies in the matter of angle of attacks, flap angles, Re, Cμ and F+ provide a convincing collection of evidence to the following conclusion. An improvement of a direct closed loop control was demonstrated, and an analytical formula describing the properties of a separated flow and vortex shedding was proposed. Best AFC solutions are offered by providing optimal frequencies and momentum ratios at a variety of flow conditions.

Quantum hacking on a practical continuous-variable quantum cryptosystem by inserting an external light

NASA Astrophysics Data System (ADS)

Qin, Hao; Kumar, Rupesh; Alleaume, Romain

2015-10-01

We report here a new side channel attack on a practical continuous-variable (CV) quantum key distribution (QKD) system. Inspired by blinding attack in discrete-variable QKD, we formalize an attack strategy by inserting an external light into a CV QKD system implemented Gaussian-modulated coherent state protocol and show that our attack can compromise its practical security. In this attack, we concern imperfections of a balanced homodyne detector used in CV QKD. According to our analysis, if one inserts an external light into Bob's signal port, due to the imperfect subtraction from the homodyne detector, the leakage of the external light contributes a displacement on the homodyne signal which causes detector electronics saturation. In consequence, Bob's quadrature measurement is not linear with the quadrature sent by Alice. By considering such vulnerability, a potential Eve can launch a full intercept-resend attack meanwhile she inserts an external light into Bob's signal port. By selecting proper properties of the external light, Eve actively controls the induced displacement value from the inserted light which results saturation of homodyne detection. In consequence, Eve can bias the excess noise due to the intercept-resend attack and the external light, such that Alice and Bob believe their excess noise estimation is below the null key threshold and they can still share a secret key. Our attack shows that the detector loopholes also exist in CV QKD, and it seems influence all the CV QKD systems using homodyne detection, since all the practical detectors have finite detection range.

Selective Optimization

DTIC Science & Technology

2015-07-06

NUMBER 5b. GRANT NUMBER AFOSR FA9550-12-1-0154 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Shabbir Ahmed and Santanu S. Dey 5d. PROJECT NUMBER 5e. TASK...standard mixed-integer programming (MIP) formulations of selective optimization problems. While such formulations can be attacked by commercial...F33615-86-C-5169. 5b. GRANT NUMBER. Enter all grant numbers as they appear in the report, e.g. AFOSR-82-1234. 5c. PROGRAM ELEMENT NUMBER. Enter

Modeling Adversaries in Counterterrorism Decisions Using Prospect Theory.

PubMed

Merrick, Jason R W; Leclerc, Philip

2016-04-01

Counterterrorism decisions have been an intense area of research in recent years. Both decision analysis and game theory have been used to model such decisions, and more recently approaches have been developed that combine the techniques of the two disciplines. However, each of these approaches assumes that the attacker is maximizing its utility. Experimental research shows that human beings do not make decisions by maximizing expected utility without aid, but instead deviate in specific ways such as loss aversion or likelihood insensitivity. In this article, we modify existing methods for counterterrorism decisions. We keep expected utility as the defender's paradigm to seek for the rational decision, but we use prospect theory to solve for the attacker's decision to descriptively model the attacker's loss aversion and likelihood insensitivity. We study the effects of this approach in a critical decision, whether to screen containers entering the United States for radioactive materials. We find that the defender's optimal decision is sensitive to the attacker's levels of loss aversion and likelihood insensitivity, meaning that understanding such descriptive decision effects is important in making such decisions. © 2014 Society for Risk Analysis.

AVQS: Attack Route-Based Vulnerability Quantification Scheme for Smart Grid

PubMed Central

Lim, Hyunwoo; Lee, Seokjun; Shon, Taeshik

2014-01-01

A smart grid is a large, consolidated electrical grid system that includes heterogeneous networks and systems. Based on the data, a smart grid system has a potential security threat in its network connectivity. To solve this problem, we develop and apply a novel scheme to measure the vulnerability in a smart grid domain. Vulnerability quantification can be the first step in security analysis because it can help prioritize the security problems. However, existing vulnerability quantification schemes are not suitable for smart grid because they do not consider network vulnerabilities. We propose a novel attack route-based vulnerability quantification scheme using a network vulnerability score and an end-to-end security score, depending on the specific smart grid network environment to calculate the vulnerability score for a particular attack route. To evaluate the proposed approach, we derive several attack scenarios from the advanced metering infrastructure domain. The experimental results of the proposed approach and the existing common vulnerability scoring system clearly show that we need to consider network connectivity for more optimized vulnerability quantification. PMID:25152923

Information hiding techniques for infrared images: exploring the state-of-the art and challenges

NASA Astrophysics Data System (ADS)

Pomponiu, Victor; Cavagnino, Davide; Botta, Marco; Nejati, Hossein

2015-10-01

The proliferation of Infrared technology and imaging systems enables a different perspective to tackle many computer vision problems in defense and security applications. Infrared images are widely used by the law enforcement, Homeland Security and military organizations to achieve a significant advantage or situational awareness, and thus is vital to protect these data against malicious attacks. Concurrently, sophisticated malware are developed which are able to disrupt the security and integrity of these digital media. For instance, illegal distribution and manipulation are possible malicious attacks to the digital objects. In this paper we explore the use of a new layer of defense for the integrity of the infrared images through the aid of information hiding techniques such as watermarking. In this context, we analyze the efficiency of several optimal decoding schemes for the watermark inserted into the Singular Value Decomposition (SVD) domain of the IR images using an additive spread spectrum (SS) embedding framework. In order to use the singular values (SVs) of the IR images with the SS embedding we adopt several restrictions that ensure that the values of the SVs will maintain their statistics. For both the optimal maximum likelihood decoder and sub-optimal decoders we assume that the PDF of SVs can be modeled by the Weibull distribution. Furthermore, we investigate the challenges involved in protecting and assuring the integrity of IR images such as data complexity and the error probability behavior, i.e., the probability of detection and the probability of false detection, for the applied optimal decoders. By taking into account the efficiency and the necessary auxiliary information for decoding the watermark, we discuss the suitable decoder for various operating situations. Experimental results are carried out on a large dataset of IR images to show the imperceptibility and efficiency of the proposed scheme against various attack scenarios.

The Adherence eValuation After Ischemic Stroke Longitudinal (AVAIL) registry: design, rationale, and baseline patient characteristics.

PubMed

Bushnell, Cheryl; Zimmer, Louise; Schwamm, Lee; Goldstein, Larry B; Clapp-Channing, Nancy; Harding, Tina; Drew, Laura; Zhao, Xin; Peterson, Eric

2009-03-01

Approximately one third of the 780,000 people in the United States who have a stroke each year have recurrent events. Although efficacious secondary prevention measures are available, levels of adherence to these strategies in patients who have had stroke are largely unknown. Understanding medication-taking behavior in this population is an important step to optimizing the appropriate use of proven secondary preventive therapies and reducing the risk of recurrent stroke. The Adherence eValuation After Ischemic Stroke Longitudinal (AVAIL) registry is a prospective study of adherence to stroke prevention medications from hospital discharge to 1 year in patients admitted with stroke or transient ischemic attack. The primary outcomes are medication usage as determined by patient interviews after 3 and 12 months. Potential patient-, provider-, and system-level barriers to persistence of medication use are also collected. Secondary outcomes include the rates of recurrent stroke or transient ischemic attack, vascular events, and rehospitalization and functional status as measured by the modified Rankin score. The AVAIL enrolled about 2,900 subjects from 106 hospitals from July 2006 through July 2008. The 12-month follow-up will be completed in August 2009. The AVAIL registry will document the current state of adherence and persistence to stroke prevention medications among a nationwide sample of patients. These data will be used to design interventions to improve the quality of care post acute hospitalization and reduce the risks of future stroke and cardiovascular events.

Binary Hypothesis Testing With Byzantine Sensors: Fundamental Tradeoff Between Security and Efficiency

NASA Astrophysics Data System (ADS)

Ren, Xiaoqiang; Yan, Jiaqi; Mo, Yilin

2018-03-01

This paper studies binary hypothesis testing based on measurements from a set of sensors, a subset of which can be compromised by an attacker. The measurements from a compromised sensor can be manipulated arbitrarily by the adversary. The asymptotic exponential rate, with which the probability of error goes to zero, is adopted to indicate the detection performance of a detector. In practice, we expect the attack on sensors to be sporadic, and therefore the system may operate with all the sensors being benign for extended period of time. This motivates us to consider the trade-off between the detection performance of a detector, i.e., the probability of error, when the attacker is absent (defined as efficiency) and the worst-case detection performance when the attacker is present (defined as security). We first provide the fundamental limits of this trade-off, and then propose a detection strategy that achieves these limits. We then consider a special case, where there is no trade-off between security and efficiency. In other words, our detection strategy can achieve the maximal efficiency and the maximal security simultaneously. Two extensions of the secure hypothesis testing problem are also studied and fundamental limits and achievability results are provided: 1) a subset of sensors, namely "secure" sensors, are assumed to be equipped with better security countermeasures and hence are guaranteed to be benign, 2) detection performance with unknown number of compromised sensors. Numerical examples are given to illustrate the main results.

Shilling attack detection for recommender systems based on credibility of group users and rating time series.

PubMed

Zhou, Wei; Wen, Junhao; Qu, Qiang; Zeng, Jun; Cheng, Tian

2018-01-01

Recommender systems are vulnerable to shilling attacks. Forged user-generated content data, such as user ratings and reviews, are used by attackers to manipulate recommendation rankings. Shilling attack detection in recommender systems is of great significance to maintain the fairness and sustainability of recommender systems. The current studies have problems in terms of the poor universality of algorithms, difficulty in selection of user profile attributes, and lack of an optimization mechanism. In this paper, a shilling behaviour detection structure based on abnormal group user findings and rating time series analysis is proposed. This paper adds to the current understanding in the field by studying the credibility evaluation model in-depth based on the rating prediction model to derive proximity-based predictions. A method for detecting suspicious ratings based on suspicious time windows and target item analysis is proposed. Suspicious rating time segments are determined by constructing a time series, and data streams of the rating items are examined and suspicious rating segments are checked. To analyse features of shilling attacks by a group user's credibility, an abnormal group user discovery method based on time series and time window is proposed. Standard testing datasets are used to verify the effect of the proposed method.

Protecting water and wastewater infrastructure from cyber attacks

NASA Astrophysics Data System (ADS)

Panguluri, Srinivas; Phillips, William; Cusimano, John

2011-12-01

Multiple organizations over the years have collected and analyzed data on cyber attacks and they all agree on one conclusion: cyber attacks are real and can cause significant damages. This paper presents some recent statistics on cyber attacks and resulting damages. Water and wastewater utilities must adopt countermeasures to prevent or minimize the damage in case of such attacks. Many unique challenges are faced by the water and wastewater industry while selecting and implementing security countermeasures; the key challenges are: 1) the increasing interconnection of their business and control system networks, 2) large variation of proprietary industrial control equipment utilized, 3) multitude of cross-sector cyber-security standards, and 4) the differences in the equipment vendor's approaches to meet these security standards. The utilities can meet these challenges by voluntarily selecting and adopting security standards, conducting a gap analysis, performing vulnerability/risk analysis, and undertaking countermeasures that best meets their security and organizational requirements. Utilities should optimally utilize their limited resources to prepare and implement necessary programs that are designed to increase cyber-security over the years. Implementing cyber security does not necessarily have to be expensive, substantial improvements can be accomplished through policy, procedure, training and awareness. Utilities can also get creative and allocate more funding through annual budgets and reduce dependence upon capital improvement programs to achieve improvements in cyber-security.

Shilling attack detection for recommender systems based on credibility of group users and rating time series

PubMed Central

Wen, Junhao; Qu, Qiang; Zeng, Jun; Cheng, Tian

2018-01-01

Recommender systems are vulnerable to shilling attacks. Forged user-generated content data, such as user ratings and reviews, are used by attackers to manipulate recommendation rankings. Shilling attack detection in recommender systems is of great significance to maintain the fairness and sustainability of recommender systems. The current studies have problems in terms of the poor universality of algorithms, difficulty in selection of user profile attributes, and lack of an optimization mechanism. In this paper, a shilling behaviour detection structure based on abnormal group user findings and rating time series analysis is proposed. This paper adds to the current understanding in the field by studying the credibility evaluation model in-depth based on the rating prediction model to derive proximity-based predictions. A method for detecting suspicious ratings based on suspicious time windows and target item analysis is proposed. Suspicious rating time segments are determined by constructing a time series, and data streams of the rating items are examined and suspicious rating segments are checked. To analyse features of shilling attacks by a group user’s credibility, an abnormal group user discovery method based on time series and time window is proposed. Standard testing datasets are used to verify the effect of the proposed method. PMID:29742134

Prior Population Immunity Reduces the Expected Impact of CTL-Inducing Vaccines for Pandemic Influenza Control

PubMed Central

Bolton, Kirsty J.; McCaw, James M.; Brown, Lorena; Jackson, David; Kedzierska, Katherine; McVernon, Jodie

2015-01-01

Vaccines that trigger an influenza-specific cytotoxic T cell (CTL) response may aid pandemic control by limiting the transmission of novel influenza A viruses (IAV). We consider interventions with hypothetical CTL-inducing vaccines in a range of epidemiologically plausible pandemic scenarios. We estimate the achievable reduction in the attack rate, and, by adopting a model linking epidemic progression to the emergence of IAV variants, the opportunity for antigenic drift. We demonstrate that CTL-inducing vaccines have limited utility for modifying population-level outcomes if influenza-specific T cells found widely in adults already suppress transmission and prove difficult to enhance. Administration of CTL-inducing vaccines that are efficacious in "influenza-experienced" and "influenza-naive" hosts can likely slow transmission sufficiently to mitigate a moderate IAV pandemic. However if neutralising cross-reactive antibody to an emerging IAV are common in influenza-experienced hosts, as for the swine-variant H3N2v, boosting CTL immunity may be ineffective at reducing population spread, indicating that CTL-inducing vaccines are best used against novel subtypes such as H7N9. Unless vaccines cannot readily suppress transmission from infected hosts with naive T cell pools, targeting influenza-naive hosts is preferable. Such strategies are of enhanced benefit if naive hosts are typically intensively mixing children and when a subset of experienced hosts have pre-existing neutralising cross-reactive antibody. We show that CTL-inducing vaccination campaigns may have greater power to suppress antigenic drift than previously suggested, and targeting adults may be the optimal strategy to achieve this when the vaccination campaign does not have the power to curtail the attack rate. Our results highlight the need to design interventions based on pre-existing cellular immunity and knowledge of the host determinants of vaccine efficacy, and provide a framework for assessing the performance requirements of high-impact CTL-inducing vaccines. PMID:25811654

Initiating and optimizing acute therapy for migraine: the role of patient-centered stratified care.

PubMed

Diamond, Merle; Cady, Roger

2005-03-01

Migraine is a chronic, intermittently disabling condition that affects physical, mental, and social aspects of health-related quality of life. Because patients seeking assistance with migraine most often present to primary care providers, these healthcare professionals play critical roles in the diagnosis and treatment process. A comprehensive migraine management plan involves a partnership between the patient and healthcare professional where treatment goals and strategies are established. Elements of such a plan should include preventive strategies to reduce the frequency and effects of future attacks as well as the use of acute treatments to address the immediate need for relief during an attack. Approaches to prevention include education, lifestyle modification, and, often, appropriate medication. Many medications have been used for acute treatment. Nonspecific agents include nonsteroidal anti-inflammatory drugs (NSAIDs), single or combination analgesics (sometimes including antiemetics or caffeine), and narcotics. Migraine-specific medications include ergot alkaloids and triptans (5-hydroxytryptamine(1B/1D) agonists). Various professional organizations have created guidelines to help providers in choosing appropriate management interventions. Clinical approaches to the patient with migraine include step care, whereby all patients begin on a simple or nonspecific treatment, stepping up to the next level of therapy if treatment is unsuccessful; or stratified care, whereby first-line therapy is tailored to the severity of the patient's pattern of headache. Studies have demonstrated that for more disabled headache patients, the stratified-care approach results in more robust headache response with less disability and greater cost-effectiveness than step care. Patient satisfaction studies demonstrate that the use of migraine-specific abortive medications (triptans) is associated with a higher satisfaction rate than over-the-counter preparations, NSAIDs, and analgesic combinations. Patients who initially reported satisfaction with the latter medications also reported a preference for triptan therapy. Healthcare professionals can assist patients, not only by choosing the most appropriate medication but also by assessing whether the level of benefit the patient is currently receiving could be improved.

Prior population immunity reduces the expected impact of CTL-inducing vaccines for pandemic influenza control.

PubMed

Bolton, Kirsty J; McCaw, James M; Brown, Lorena; Jackson, David; Kedzierska, Katherine; McVernon, Jodie

2015-01-01

Vaccines that trigger an influenza-specific cytotoxic T cell (CTL) response may aid pandemic control by limiting the transmission of novel influenza A viruses (IAV). We consider interventions with hypothetical CTL-inducing vaccines in a range of epidemiologically plausible pandemic scenarios. We estimate the achievable reduction in the attack rate, and, by adopting a model linking epidemic progression to the emergence of IAV variants, the opportunity for antigenic drift. We demonstrate that CTL-inducing vaccines have limited utility for modifying population-level outcomes if influenza-specific T cells found widely in adults already suppress transmission and prove difficult to enhance. Administration of CTL-inducing vaccines that are efficacious in "influenza-experienced" and "influenza-naive" hosts can likely slow transmission sufficiently to mitigate a moderate IAV pandemic. However if neutralising cross-reactive antibody to an emerging IAV are common in influenza-experienced hosts, as for the swine-variant H3N2v, boosting CTL immunity may be ineffective at reducing population spread, indicating that CTL-inducing vaccines are best used against novel subtypes such as H7N9. Unless vaccines cannot readily suppress transmission from infected hosts with naive T cell pools, targeting influenza-naive hosts is preferable. Such strategies are of enhanced benefit if naive hosts are typically intensively mixing children and when a subset of experienced hosts have pre-existing neutralising cross-reactive antibody. We show that CTL-inducing vaccination campaigns may have greater power to suppress antigenic drift than previously suggested, and targeting adults may be the optimal strategy to achieve this when the vaccination campaign does not have the power to curtail the attack rate. Our results highlight the need to design interventions based on pre-existing cellular immunity and knowledge of the host determinants of vaccine efficacy, and provide a framework for assessing the performance requirements of high-impact CTL-inducing vaccines.

Danger Comes from All Fronts: Predator-Dependent Escape Tactics of Túngara Frogs

PubMed Central

Bulbert, Matthew W.; Page, Rachel A.; Bernal, Ximena E.

2015-01-01

The escape response of an organism is generally its last line of defense against a predator. Because the effectiveness of an escape varies with the approach behaviour of the predator, it should be advantageous for prey to alter their escape trajectories depending on the mode of predator attack. To test this hypothesis we examined the escape responses of a single prey species, the ground-dwelling túngara frog (Engystomops pustulosus), to disparate predators approaching from different spatial planes: a terrestrial predator (snake) and an aerial predator (bat). Túngara frogs showed consistently distinct escape responses when attacked by terrestrial versus aerial predators. The frogs fled away from the snake models (Median: 131°). In stark contrast, the frogs moved toward the bat models (Median: 27°); effectively undercutting the bat’s flight path. Our results reveal that prey escape trajectories reflect the specificity of their predators’ attacks. This study emphasizes the flexibility of strategies performed by prey to outcompete predators with diverse modes of attack. PMID:25874798

Minimum State Awareness for Resilient Control Systems Under Cyber-Attack

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kisner, Roger; Fugate, David L; McIntyre, Timothy J

2012-01-01

State awareness for a control system is the accurate knowledge of the internal states of the system realization. To maintain stable operation, a controller requires a certain degree of state awareness. By definition, a cyber-attacker decreases the state awareness by modifying or removing the information available to the operator and control system. By doing so, the attacker can directly cause damage to the physical system through the control system, or indirectly by causing the operator to react in a damaging manner to the false information. In a number of recent papers, detection and mitigation strategies have been proposed that assumemore » state awareness. The goal of the attacker to reduce or remove state awareness makes this assumption invalid for most situations. One of the central problems of resilient control is developing methods to retain sufficient state awareness to continue operation during a cyberattack. In this paper, we will define state awareness, discuss the consequences of loss of state awareness, and some potential research directions for maintaining state awareness.« less

An attack aimed at active phase compensation in one-way phase-encoded QKD systems

NASA Astrophysics Data System (ADS)

Dong, Zhao-Yue; Yu, Ning-Na; Wei, Zheng-Jun; Wang, Jin-Dong; Zhang, Zhi-Ming

2014-08-01

Phase drift is an inherent problem in one-way phase-encoded quantum key distribution (QKD) systems. Although combining passive with active phase compensation (APC) processes can effectively compensate for the phase drift, the security problems brought about by these processes are rarely considered. In this paper, we point out a security hole in the APC process and put forward a corresponding attack scheme. Under our proposed attack, the quantum bit error rate (QBER) of the QKD can be close to zero for some conditions. However, under the same conditions the ratio r of the key "0" and the key "1" which Bob (the legal communicators Alice and Bob) gets is no longer 1:1 but 2:1, which may expose Eve (the eavesdropper). In order to solve this problem, we modify the resend strategy of the attack scheme, which can force r to reach 1 and the QBER to be lower than the tolerable QBER.

Mediating the social and psychological impacts of terrorist attacks: the role of risk perception and risk communication.

PubMed

Rogers, M Brooke; Amlôt, Richard; Rubin, G James; Wessely, Simon; Krieger, Kristian

2007-06-01

The public's understanding of chemical, biological, radiological and nuclear (CBRN) related issues and their likely actions following a CBRN incident is an issue of great concern, as public psychological and behavioural responses will help determine subsequent morbidity and mortality rates. This paper explores the role of effective government communication with the public and its role in mediating the social and psychological impact of terrorist attacks. We examine the importance of effective communication in reducing morbidity and mortality in the event of a terrorist attack and explore the impact of risk perceptions in determining the success or failure of risk communication strategies. This includes the examination of the role of fear as a health risk, and the identification of factors relevant to public trust in risk communication. Finally, an investigation of the type of information desired by members of the public leads the authors to make risk communication recommendations targeted at the promotion of more adaptive behaviours in response to CBRN attacks.

Understanding public confidence in government to prevent terrorist attacks.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baldwin, T. E.; Ramaprasad, A,; Samsa, M. E.

A primary goal of terrorism is to instill a sense of fear and vulnerability in a population and to erode its confidence in government and law enforcement agencies to protect citizens against future attacks. In recognition of its importance, the Department of Homeland Security includes public confidence as one of the principal metrics used to assess the consequences of terrorist attacks. Hence, a detailed understanding of the variations in public confidence among individuals, terrorist event types, and as a function of time is critical to developing this metric. In this exploratory study, a questionnaire was designed, tested, and administered tomore » small groups of individuals to measure public confidence in the ability of federal, state, and local governments and their public safety agencies to prevent acts of terrorism. Data was collected from three groups before and after they watched mock television news broadcasts portraying a smallpox attack, a series of suicide bomber attacks, a refinery explosion attack, and cyber intrusions on financial institutions, resulting in identity theft. Our findings are: (a) although the aggregate confidence level is low, there are optimists and pessimists; (b) the subjects are discriminating in interpreting the nature of a terrorist attack, the time horizon, and its impact; (c) confidence recovery after a terrorist event has an incubation period; and (d) the patterns of recovery of confidence of the optimists and the pessimists are different. These findings can affect the strategy and policies to manage public confidence after a terrorist event.« less

Does fluoride in drinking water delay tooth eruption?

PubMed

Jolaoso, Ismail Adeyemi; Kumar, Jayanth; Moss, Mark E

2014-01-01

The objectives of this study are to determine the effect of fluoride exposure on permanent tooth eruption patterns as well as to understand its effect on caries attack rate by accounting for the number of erupted tooth surfaces. We analyzed data from the 1986-1987 National Survey of Oral Health of US Schoolchildren to determine the mean number of erupted permanent teeth and permanent first molars according to fluoride level in drinking water. The analysis included 13,348 children aged 5-17 years with a history of single residence. We also estimated the attack rate (decayed, missing, and filled surfaces/surfaces at risk) for fluoride deficient, suboptimal, and optimally fluoridated areas adjusting for covariates. Multivariable statistical analyses were performed to control for potential confounders. By age 7, almost all permanent first molars had erupted. The adjusted mean number of erupted permanent first molars per child were 3.81, 3.67, and 3.92 in areas with <0.3, 0.3-<0.7, and 0.7-1.2 ppm of fluoride, respectively. The adjusted caries attack rate in the first permanent molars among 5- to 17-year-old children was 93, 81, and 78 per 1,000 surfaces in fluoride deficient, suboptimal, and optimally fluoridated areas, respectively (P < 0.0001). This pattern of higher first molar attack rate among children in the fluoride-deficient communities was also observed in all erupted teeth. Exposure to fluoride in drinking water did not delay the eruption of permanent teeth. The observed difference in dental caries experience among children exposed to different fluoride levels could not be explained by the timing of eruption of permanent teeth. © 2014 American Association of Public Health Dentistry.

Cerebrovascular blood pressure autoregulation monitoring and postoperative transient ischemic attack in pediatric moyamoya vasculopathy.

PubMed

Lee, Jennifer K; Williams, Monica; Reyes, Michael; Ahn, Edward S

2018-02-01

Children with moyamoya vasculopathy are at high risk of perioperative cerebral ischemia or hyperperfusion. Maintaining blood pressure within the range of functional cerebrovascular blood pressure autoregulation might reduce the risk of perioperative neurologic injury. We tested whether blood pressure autoregulation is associated with postoperative transient ischemic attack in a study of patients with pediatric moyamoya vasculopathy. We conducted an observational study of 15 pediatric patients undergoing surgical revascularization with pial synangiosis. Nine patients had bilateral moyamoya and 6 had unilateral moyamoya. We measured autoregulatory vasoreactivity intraoperatively and during the first postoperative night with the hemoglobin volume index, a value derived from near-infrared spectroscopy. We also identified the optimal mean arterial blood pressure at which autoregulation was most robust in each patient. Of the 15 children monitored, 3 with bilateral moyamoya and one with unilateral moyamoya experienced a transient ischemic attack. Poorer autoregulation during surgery was associated with postoperative transient ischemic attack among those with bilateral vasculopathy (P = .048, difference in hemoglobin volume index medians: 0.023, 95% confidence interval: 0.003-0.071). This relationship was not observed with postoperative autoregulation. The optimal mean arterial blood pressure was identifiable during surgery in all monitored patients, varied among patients, and often differed between the intraoperative and postoperative periods. Dysfunctional intraoperative autoregulation may increase the risk of TIA in patients with pediatric moyamoya vasculopathy. The blood pressure range that supports autoregulation appears to vary among patients. Using autoregulation monitoring to guide individualized blood pressure goals should be studied as a potential method to reduce perioperative neurologic morbidity in pediatric patients with moyamoya. © 2017 John Wiley & Sons Ltd.

Optimizing a tandem disk model

NASA Astrophysics Data System (ADS)

Healey, J. V.

1983-08-01

The optimum values of the solidity ratio, tip speed ratio (TSR), and the preset angle of attack, the corresponding distribution, and the breakdown mechanism for a tandem disk model for a crosswind machine such as a Darrieus are examined analytically. Equations are formulated for thin blades with zero drag in consideration of two plane rectangular disks, both perpendicular to the wind flow. Power coefficients are obtained for both disks and comparisons are made between a single-disk system and a two-disk system. The power coefficient for the tandem disk model is shown to be a sum of the coefficients of the individual disks, with a maximum value of twice the Betz limit at an angle of attack of -1 deg and the TSR between 4-7. The model, applied to the NACA 0012 profile, gives a maximum power coefficient of 0.967 with a solidity ratio of 0.275 and highly limited ranges for the angle of attack and TSR.

A simple analytical aerodynamic model of Langley Winged-Cone Aerospace Plane concept

NASA Technical Reports Server (NTRS)

Pamadi, Bandu N.

1994-01-01

A simple three DOF analytical aerodynamic model of the Langley Winged-Coned Aerospace Plane concept is presented in a form suitable for simulation, trajectory optimization, and guidance and control studies. The analytical model is especially suitable for methods based on variational calculus. Analytical expressions are presented for lift, drag, and pitching moment coefficients from subsonic to hypersonic Mach numbers and angles of attack up to +/- 20 deg. This analytical model has break points at Mach numbers of 1.0, 1.4, 4.0, and 6.0. Across these Mach number break points, the lift, drag, and pitching moment coefficients are made continuous but their derivatives are not. There are no break points in angle of attack. The effect of control surface deflection is not considered. The present analytical model compares well with the APAS calculations and wind tunnel test data for most angles of attack and Mach numbers.

Experimental quantum key distribution with finite-key security analysis for noisy channels.

PubMed

Bacco, Davide; Canale, Matteo; Laurenti, Nicola; Vallone, Giuseppe; Villoresi, Paolo

2013-01-01

In quantum key distribution implementations, each session is typically chosen long enough so that the secret key rate approaches its asymptotic limit. However, this choice may be constrained by the physical scenario, as in the perspective use with satellites, where the passage of one terminal over the other is restricted to a few minutes. Here we demonstrate experimentally the extraction of secure keys leveraging an optimal design of the prepare-and-measure scheme, according to recent finite-key theoretical tight bounds. The experiment is performed in different channel conditions, and assuming two distinct attack models: individual attacks or general quantum attacks. The request on the number of exchanged qubits is then obtained as a function of the key size and of the ambient quantum bit error rate. The results indicate that viable conditions for effective symmetric, and even one-time-pad, cryptography are achievable.

A Strategy Based on Protein-Protein Interface Motifs May Help in Identifying Drug Off-Targets

PubMed Central

Engin, H. Billur; Keskin, Ozlem; Nussinov, Ruth; Gursoy, Attila

2014-01-01

Networks are increasingly used to study the impact of drugs at the systems level. From the algorithmic standpoint, a drug can ‘attack’ nodes or edges of a protein-protein interaction network. In this work, we propose a new network strategy, “The Interface Attack”, based on protein-protein interfaces. Similar interface architectures can occur between unrelated proteins. Consequently, in principle, a drug that binds to one has a certain probability of binding others. The interface attack strategy simultaneously removes from the network all interactions that consist of similar interface motifs. This strategy is inspired by network pharmacology and allows inferring potential off-targets. We introduce a network model which we call “Protein Interface and Interaction Network (P2IN)”, which is the integration of protein-protein interface structures and protein interaction networks. This interface-based network organization clarifies which protein pairs have structurally similar interfaces, and which proteins may compete to bind the same surface region. We built the P2IN of p53 signaling network and performed network robustness analysis. We show that (1) ‘hitting’ frequent interfaces (a set of edges distributed around the network) might be as destructive as eleminating high degree proteins (hub nodes); (2) frequent interfaces are not always topologically critical elements in the network; and (3) interface attack may reveal functional changes in the system better than attack of single proteins. In the off-target detection case study, we found that drugs blocking the interface between CDK6 and CDKN2D may also affect the interaction between CDK4 and CDKN2D. PMID:22817115

Suicide Bombing Attacks

PubMed Central

Almogy, Gidon; Belzberg, Howard; Mintz, Yoaz; Pikarsky, Alon K.; Zamir, Gideon; Rivkind, Avraham I.

2004-01-01

Objective: To review the experience of a large-volume trauma center in managing and treating casualties of suicide bombing attacks. Summary Background Data: The threat of suicide bombing attacks has escalated worldwide. The ability of the suicide bomber to deliver a relatively large explosive load accompanied by heavy shrapnel to the proximity of his or her victims has caused devastating effects. Methods: The authors reviewed and analyzed the experience obtained in treating victims of suicide bombings at the level I trauma center of the Hadassah University Hospital in Jerusalem, Israel from 2000 to 2003. Results: Evacuation is usually rapid due to the urban setting of these attacks. Numerous casualties are brought into the emergency department over a short period. The setting in which the device is detonated has implications on the type of injuries sustained by survivors. The injuries sustained by victims of suicide bombing attacks in semi-confined spaces are characterized by the degree and extent of widespread tissue damage and include multiple penetrating wounds of varying severity and location, blast injury, and burns. Conclusions: The approach to victims of suicide bombings is based on the guidelines for trauma management. Attention is given to the moderately injured, as these patients may harbor immediate life-threatening injuries. The concept of damage control can be modified to include rapid packing of multiple soft-tissue entry sites. Optimal utilization of manpower and resources is achieved by recruiting all available personnel, adopting a predetermined plan, and a centrally coordinated approach. Suicide bombing attacks seriously challenge the most experienced medical facilities. PMID:15075644

Suicide bombing attacks: update and modifications to the protocol.

PubMed

Almogy, Gidon; Belzberg, Howard; Mintz, Yoaz; Pikarsky, Alon K; Zamir, Gideon; Rivkind, Avraham I

2004-03-01

To review the experience of a large-volume trauma center in managing and treating casualties of suicide bombing attacks. The threat of suicide bombing attacks has escalated worldwide. The ability of the suicide bomber to deliver a relatively large explosive load accompanied by heavy shrapnel to the proximity of his or her victims has caused devastating effects. The authors reviewed and analyzed the experience obtained in treating victims of suicide bombings at the level I trauma center of the Hadassah University Hospital in Jerusalem, Israel from 2000 to 2003. Evacuation is usually rapid due to the urban setting of these attacks. Numerous casualties are brought into the emergency department over a short period. The setting in which the device is detonated has implications on the type of injuries sustained by survivors. The injuries sustained by victims of suicide bombing attacks in semi-confined spaces are characterized by the degree and extent of widespread tissue damage and include multiple penetrating wounds of varying severity and location, blast injury, and burns. The approach to victims of suicide bombings is based on the guidelines for trauma management. Attention is given to the moderately injured, as these patients may harbor immediate life-threatening injuries. The concept of damage control can be modified to include rapid packing of multiple soft-tissue entry sites. Optimal utilization of manpower and resources is achieved by recruiting all available personnel, adopting a predetermined plan, and a centrally coordinated approach. Suicide bombing attacks seriously challenge the most experienced medical facilities.

Exposure-Response Model of Subcutaneous C1-Inhibitor Concentrate to Estimate the Risk of Attacks in Patients With Hereditary Angioedema.

PubMed

Zhang, Ying; Tortorici, Michael A; Pawaskar, Dipti; Pragst, Ingo; Machnig, Thomas; Hutmacher, Matthew; Zuraw, Bruce; Cicardi, Marco; Craig, Timothy; Longhurst, Hilary; Sidhu, Jagdev

2018-03-01

Subcutaneous C1-inhibitor (HAEGARDA, CSL Behring), is a US Food and Drug Administration (FDA)-approved, highly concentrated formulation of a plasma-derived C1-esterase inhibitor (C1-INH), which, in the phase III Clinical Studies for Optimal Management in Preventing Angioedema with Low-Volume Subcutaneous C1-inhibitor Replacement Therapy (COMPACT) trial, reduced the incidence of hereditary angioedema (HAE) attacks when given prophylactically. Data from the COMPACT trial were used to develop a repeated time-to-event model to characterize the timing and frequency of HAE attacks as a function of C1-INH activity, and then develop an exposure-response model to assess the relationship between C1-INH functional activity levels (C1-INH(f)) and the risk of an attack. The C1-INH(f) values of 33.1%, 40.3%, and 63.1% were predicted to correspond with 50%, 70%, and 90% reductions in the HAE attack risk, respectively, relative to no therapy. Based on trough C1-INH(f) values for the 40 IU/kg (40.2%) and 60 IU/kg (48.0%) C1-INH (SC) doses, the model predicted that 50% and 67% of the population, respectively, would see at least a 70% decrease in the risk of an attack. © 2018 The Authors CPT: Pharmacometrics & Systems Pharmacology published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.

Depredation of domestic herds by pumas based on farmer's information in Southern Brazil.

PubMed

Schulz, Francine; Printes, Rodrigo C; Oliveira, Larissa R

2014-10-15

Large carnivores such as pumas are frequently killed due to conflicts with human populations involving predation on domestic herds. In Southern Brazil, traditional pasture systems, where animals feed without specific husbandry practices is typical, becoming the herds vulnerable to puma attacks. The aim of this study was to examine the conflict between local people and pumas in a Protected Areas mosaic in southern Brazil. Forty-five face-to-face interviews with local people were performed during the year of 2011, using a structured questionnaire with open and closed questions about puma attack episodes in some farms. Based on responses, the conflict and puma attacks were described, and the characteristics of attacked farms and estimated financial losses were evaluated. The first respondents were indicated by the Local Environmental Agency, and the others were indicated by the first one and so on, which is known as "snow-ball" method. Our data suggested that pumas used to attack in unfavorable conditions of visibility (foggy days) and on easier prey (e.g. sheep). Most of the attacks reported were close to forested areas and were focused on free herds during feeding activities. Some farmers said they gave up their sheep breeding activity due to losses caused by puma attacks. However, some farmers could over estimate their losses. Moreover, pumas were considered a threat to domestic herds and respondents mentioned cases of illegal puma hunting in the area. The results of questionnaires suggested that puma attack episodes were related to fragmentation of their habitat associated to incorrect management of herds in the farms studied. The diagnosis of this type of conflict and the characterization of most attacked sites are extremely important to create strategies to prevent and control attacks by wild carnivores. Deep changes in husbandry practices added to educational programs should be implemented, in order to maintain the sustainability of rural activities as well as the survival of pumas in southern Brazil.

Investigating the Self-Protective Potential of Immobility in Victims of Rape.

PubMed

de Heer, Brooke A; Jones, Lynn C

2017-04-01

Using a nationwide sample of reported rape cases collected by the Federal Bureau of Investigation (FBI; 389 victims; 89% stranger rapes), this study investigates assumptions about self-protective behaviors for rape victims. Past research on victim resistance strategies often specifies active resistance as self-protective, inadvertently underestimating the potential for biologically based reactions, such as tonic immobility, to be self-protective as well. Results confirm that rape victims who were verbally and physically immobile during the attack were less likely to be injured and have force used against them. In addition, victims who were verbally immobile suffered a less severe attack. The results indicate that immobility may protect the victim from increased injury, force, and severity of the attack. Implications for the legal and public definition of consent are discussed.

Hazardous material transportation and the security externality : what should be done?

DOT National Transportation Integrated Search

2013-04-01

This project examined the safety and security externalities which exists in the : transportation of hazardous materials (particularly Toxic Inhalant Hazards) and : identified alterative mitigation strategies. The combination of terrorist attack...

Logistics modelling: improving resource management and public information strategies in Florida.

PubMed

Walsh, Daniel M; Van Groningen, Chuck; Craig, Brian

2011-10-01

One of the most time-sensitive and logistically-challenging emergency response operations today is to provide mass prophylaxis to every man, woman and child in a community within 48 hours of a bioterrorism attack. To meet this challenge, federal, state and local public health departments in the USA have joined forces to develop, test and execute large-scale bioterrorism response plans. This preparedness and response effort is funded through the US Centers for Disease Control and Prevention's Cities Readiness Initiative, a programme dedicated to providing oral antibiotics to an entire population within 48 hours of a weaponised inhalation anthrax attack. This paper will demonstrate how the State of Florida used a logistics modelling tool to improve its CRI mass prophylaxis plans. Special focus will be on how logistics modelling strengthened Florida's resource management policies and validated its public information strategies.

Coping responses in the midst of terror: the July 22 terror attack at Utøya Island in Norway.

PubMed

Jensen, Tine K; Thoresen, Siri; Dyb, Grete

2015-02-01

This study examined the peri-trauma coping responses of 325 survivors, mostly youth, after the July 22, 2011 terror attack on Utøya Island in Norway. The aim was to understand peri-trauma coping responses and their relation to subsequent post-traumatic stress (PTS) reactions. Respondents were interviewed face-to-face 4-5 months after the shooting, and most were interviewed at their homes. Peri-trauma coping was assessed using ten selected items from the "How I Cope Under Pressure Scale" (HICUPS), covering the dimensions of problem solving, positive cognitive restructuring, avoidance, support seeking, seeking understanding, and religious coping. PTS reactions were assessed with the UCLA PTSD Reaction Index. The participants reported using a wide variety of coping strategies. Problem solving, positive cognitive restructuring, and seeking understanding strategies were reported most often. Men reported using more problem-solving strategies, whereas women reported more emotion-focused strategies. There were no significant associations between age and the use of coping strategies. Problem solving and positive cognitive restructuring were significantly associated with fewer PTS reactions. The results are discussed in light of previous research and may help to inform early intervention efforts for survivors of traumatic events. © 2014 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

Questing for an optimal, universal viral agent for oncolytic virotherapy

NASA Astrophysics Data System (ADS)

Paiva, L. R.; Martins, M. L.; Ferreira, S. C.

2011-10-01

One of the most promising strategies to treat cancer is attacking it with viruses designed to exploit specific altered pathways. Here, the effects of oncolytic virotherapy on tumors having compact, papillary, and disconnected morphologies are investigated through computer simulations of a multiscale model coupling macroscopic reaction-diffusion equations for the nutrients with microscopic stochastic rules for the actions of individual cells and viruses. The interaction among viruses and tumor cells involves cell infection, intracellular virus replication, and the release of new viruses in the tissue after cell lysis. The evolution over time of both the viral load and cancer cell population, as well as the probabilities for tumor eradication, were evaluated for a range of multiplicities of infection, viral entries, and burst sizes. It was found that in immunosuppressed hosts, the antitumor efficacy of a virus is primarily determined by its entry efficiency, its replicative capacity within the tumor, and its ability to spread over the tissue. However, the optimal traits for oncolytic viruses depend critically on the tumor growth dynamics and do not necessarily include rapid replication, cytolysis, or spreading, currently assumed as necessary conditions for a successful therapeutic outcome. Our findings have potential implications on the design of new vectors for the viral therapy of cancer.

Austrian Security Strategy: Need For Reformulation Due To Security Developments

DTIC Science & Technology

2016-02-14

migration from Africa and the Middle East, and reality has overtaken the security strategy. The terrorist attacks in Paris and the sexual assaults on women...legitimate use of physical force” i.e., a state is a system based on the legitimate “relation of domination of man over man.”6, 7 Strategy is...called peace dividend to stimulate the economy and invest in infrastructure projects. Modern security policy must be assessed in all areas, since

French Naval Policy Outside of Europe.

DTIC Science & Technology

1980-09-01

strategy" and "indi- rect strategy.ŝ In today’s world, direct strategy used against France would consist of overt armed aggression against French ter...8217 away at French interests one by one when he is afraid or unable to attack France directly. He would alternate local thrusts with calls for nego...of little importance to France were it not for the fact that it can endanger vital French inter- 4 ests without triggering France’s strategic

National Aviation Security Policy, Strategy, and Mode-Specific Plans: Background and Considerations for Congress

DTIC Science & Technology

2009-02-02

aviation security . The approach to aviation security was largely shaped by past events, such as the bombing of Pan Am flight 103 in December 1988, rather...community. Following the September 11, 2001, attacks, U.S. aviation security policy and strategy was closely linked to the changes called for in the...have been considered security sensitive thus limiting public discourse on the DHS strategy for aviation security . However, in June 2006 President

US Counter-Islamic State Strategy: It Could Be Worse

DTIC Science & Technology

2017-03-31

to achieve US political objectives. US Policy Towards Islamic State Modern Islamic terrorism , defined as groups professing Islamic motivations...networks, these extremist organizations adopted terrorism strategies to achieve their political goals.4 Bombing, kidnappings, hijackings and shootings...fueled by US enmity, and focused on striking the West outside of the Middle East. These efforts manifested themselves as the terror attacks on

Debugging classification and anti-debugging strategies

NASA Astrophysics Data System (ADS)

Gao, Shang; Lin, Qian; Xia, Mingyuan; Yu, Miao; Qi, Zhengwei; Guan, Haibing

2011-12-01

Debugging, albeit useful for software development, is also a double-edge sword since it could also be exploited by malicious attackers. This paper analyzes the prevailing debuggers and classifies them into 4 categories based on the debugging mechanism. Furthermore, as an opposite, we list 13 typical anti-debugging strategies adopted in Windows. These methods intercept specific execution points which expose the diagnostic behavior of debuggers.

Combating Terrorism: Issues in Managing Counterterrorist Programs

DTIC Science & Technology

2000-04-06

major effort to develop a national strategy, to date the strategy does not include a clear desired outcome to be achieved. Resources to combat...Federal exercises, in contrast to earlier years, are now practicing crisis and consequence management simultaneously and including state and local...categories—crisis management and consequence management. Crisis management includes efforts to stop a terrorist attack, arrest terrorists, and gather

Blood pressure and LDL-cholesterol targets for prevention of recurrent strokes and cognitive decline in the hypertensive patient: design of the European Society of Hypertension-Chinese Hypertension League Stroke in Hypertension Optimal Treatment randomized trial.

PubMed

Zanchetti, Alberto; Liu, Lisheng; Mancia, Giuseppe; Parati, Gianfranco; Grassi, Guido; Stramba-Badiale, Marco; Silani, Vincenzo; Bilo, Grzegorz; Corrao, Giovanni; Zambon, Antonella; Scotti, Lorenza; Zhang, Xinhua; Wang, HayYan; Zhang, Yuqing; Zhang, Xuezhong; Guan, Ting Rui; Berge, Eivind; Redon, Josep; Narkiewicz, Krzysztof; Dominiczak, Anna; Nilsson, Peter; Viigimaa, Margus; Laurent, Stéphane; Agabiti-Rosei, Enrico; Wu, Zhaosu; Zhu, Dingliang; Rodicio, José Luis; Ruilope, Luis Miguel; Martell-Claros, Nieves; Pinto, Fernando; Schmieder, Roland E; Burnier, Michel; Banach, Maciej; Cifkova, Renata; Farsang, Csaba; Konradi, Alexandra; Lazareva, Irina; Sirenko, Yuriy; Dorobantu, Maria; Postadzhiyan, Arman; Accetto, Rok; Jelakovic, Bojan; Lovic, Dragan; Manolis, Athanasios J; Stylianou, Philippos; Erdine, Serap; Dicker, Dror; Wei, Gangzhi; Xu, Chengbin; Xie, Hengge; Coca, Antonio; O'Brien, John; Ford, Gary

2014-09-01

The SBP values to be achieved by antihypertensive therapy in order to maximize reduction of cardiovascular outcomes are unknown; neither is it clear whether in patients with a previous cardiovascular event, the optimal values are lower than in the low-to-moderate risk hypertensive patients, or a more cautious blood pressure (BP) reduction should be obtained. Because of the uncertainty whether 'the lower the better' or the 'J-curve' hypothesis is correct, the European Society of Hypertension and the Chinese Hypertension League have promoted a randomized trial comparing antihypertensive treatment strategies aiming at three different SBP targets in hypertensive patients with a recent stroke or transient ischaemic attack. As the optimal level of low-density lipoprotein cholesterol (LDL-C) level is also unknown in these patients, LDL-C-lowering has been included in the design. The European Society of Hypertension-Chinese Hypertension League Stroke in Hypertension Optimal Treatment trial is a prospective multinational, randomized trial with a 3 × 2 factorial design comparing: three different SBP targets (1, <145-135; 2, <135-125; 3, <125  mmHg); two different LDL-C targets (target A, 2.8-1.8; target B, <1.8  mmol/l). The trial is to be conducted on 7500 patients aged at least 65 years (2500 in Europe, 5000 in China) with hypertension and a stroke or transient ischaemic attack 1-6 months before randomization. Antihypertensive and statin treatments will be initiated or modified using suitable registered agents chosen by the investigators, in order to maintain patients within the randomized SBP and LDL-C windows. All patients will be followed up every 3 months for BP and every 6 months for LDL-C. Ambulatory BP will be measured yearly. Primary outcome is time to stroke (fatal and non-fatal). Important secondary outcomes are: time to first major cardiovascular event; cognitive decline (Montreal Cognitive Assessment) and dementia. All major outcomes will be adjudicated by committees blind to randomized allocation. A Data and Safety Monitoring Board has open access to data and can recommend trial interruption for safety. It has been calculated that 925 patients would reach the primary outcome after a mean 4-year follow-up, and this should provide at least 80% power to detect a 25% stroke difference between SBP targets and a 20% difference between LDL-C targets.

Nuclear Attack on U.S. Space-Based Assets: Current Strategy, Policy, Reality, and Implications for the Future.

DTIC Science & Technology

1998-06-05

other.46 This can be useful when certain links 70 have been negated through the destruction of a ground station or actual jamming or interference...system is to attack the enemy’s ground station.59 The link segment can be jammed or spoofed60. However, the DoD has nothing in its inventory currently...currently conducted primarily by jamming assets that prevent the enemy use of his systems. These systems are classified and can only be discussed in

Optimal number of spacers in CRISPR arrays

PubMed Central

Severinov, Konstantin; Ispolatov, Iaroslav

2017-01-01

Prokaryotic organisms survive under constant pressure of viruses. CRISPR-Cas system provides its prokaryotic host with an adaptive immune defense against viruses that have been previously encountered. It consists of two components: Cas-proteins that cleave the foreign DNA and CRISPR array that suits as a virus recognition key. CRISPR array consists of a series of spacers, short pieces of DNA that originate from and match the corresponding parts of viral DNA called protospacers. Here we estimate the number of spacers in a CRISPR array of a prokaryotic cell which maximizes its protection against a viral attack. The optimality follows from a competition between two trends: too few distinct spacers make host vulnerable to an attack by a virus with mutated corresponding protospacers, while an excessive variety of spacers dilutes the number of the CRISPR complexes armed with the most recent and thus most useful spacers. We first evaluate the optimal number of spacers in a simple scenario of an infection by a single viral species and later consider a more general case of multiple viral species. We find that depending on such parameters as the concentration of CRISPR-Cas interference complexes and its preference to arm with more recently acquired spacers, the rate of viral mutation, and the number of viral species, the predicted optimal number of spacers lies within a range that agrees with experimentally-observed values. PMID:29253874

Electronic Attack Platform Placement Optimization

DTIC Science & Technology

2014-09-01

Processing in VBA ...............................................................33 2. Client-Server Using Two Different Excel Application...6 Figure 3. Screenshot of the VBA IDE contained within all Microsoft Office products...application using MS Excel’s Applicatin.OnTime method. .....................................33 Figure 20. WINSOCK API Functions needed to use TCP via VBA

Tri-Level Optimization Algorithms for Solving Defender-Attacker-Defender Network Models

DTIC Science & Technology

2016-06-01

ed.). New York: Springer. Brimberg, J., Hansen, P., Lin, K., Mladenović, N., & Breton, M. (2003). An Oil Pipeline Design Problem. Operations...H. (2012). Critical infrastructure protection: The vulnerability conundrum. Telematics and informatics , 29(1), 56–65. Retrieved from http

Efficacy of "Verbenone Plus" for protecting ponderosa pine trees and stands from Dendroctonus brevicomis (Coleoptera: Curculionidae) attack in British Columbia and California.

PubMed

Fettig, Christopher J; McKelvey, Stephen R; Dabney, Christopher P; Huber, Dezene P W; Lait, Cameron G; Fowler, Donald L; Borden, John H

2012-10-01

The western pine beetle, Dendroctonus brevicomis LeConte (Coleoptera: Curculionidae, Scolytinae), is a major cause of ponderosa pine, Pinus ponderosa Douglas ex Lawson, mortality in much of western North America. We review several years of research that led to the identification of Verbenone Plus, a novel four-component semiochemcial blend [acetophenone, (E)-2-hexen-1-ol + (Z)-2-hexen-1-ol, and (-)-verbenone] that inhibits the response of D. brevicomis to attractant-baited traps, and examine the efficacy of Verbenone Plus for protecting individual trees and forest stands from D. brevicomis infestations in British Columbia and California. In all experiments, semiochemicals were stapled around the bole of treated trees at approximately equal to 2 m in height. (-)-Verbenone alone had no effect on the density of total attacks and successful attacks by D. brevicomis on attractant-baited P. ponderosa, but significantly increased the percentage of pitchouts (unsuccessful D. brevicomis attacks). Verbenone Plus significantly reduced the density of D. brevicomis total attacks and D. brevicomis successful attacks on individual trees. A significantly higher percentage of pitchouts occurred on Verbenone Plus-treated trees. The application of Verbenone Plus to attractant-baited P. ponderosa significantly reduced levels of tree mortality. In stand protection studies, Verbenone Plus significantly reduced the percentage of trees mass attacked by D. brevicomis in one study, but in a second study no significant treatment effect was observed. Future research should concentrate on determining optimal release rates and spacings of release devices in stand protection studies, and expansion of Verbenone Plus into other systems where verbenone alone has not provided adequate levels of tree protection.

Numerical investigation on the performance of fin and tube heat exchangers using rectangular vortex generators

NASA Astrophysics Data System (ADS)

Zeeshan, Mohd; Hazarika, Saheera Azmi; Nath, Sujit; Bhanja, Dipankar

2017-07-01

In the present work, a 3-D numerical investigation has been performed to explore the effect of attack angles on the thermal-hydraulic performance of fin and tube heat exchanger (FTHE) using rectangular winglet pairs (RWPs). RWPs are placed adjacent to the tubes and three attack angels are considered for the study i.e. 5°, 15° and 25°. The effect of attack angles are examined on the heat transfer characteristics as well as in pressure drop penalty with airside Reynolds number Rea ranges from 500 to 900. Two performance evaluation criteria namely PEC1 i.e. area goodness factor (j/f) and PEC2 i.e. heat transfer rate per unit fan power consumption (Q/Pf) are considered for the performance evaluation. Furthermore, MOORA method is applied to obtain the performance order of FTHE configurations by taking PEC1 and PEC2 as beneficial attributes and fan power Pf as a non-beneficial attribute, keeping equal importance to each attribute. The results show that 5° attack angle provides the better performance in terms of PEC1 as heat transfer coefficient is increased by 27.70% at Rea=500 and 32.73% at Rea=900 respectively with 13.01% increased pressure drop penalty at Rea=500 and 14.26% at Rea=900 respectively. In terms of PEC2, though the 5° attack angle provides the high values of Q/Pf factor among the 15° and 25° attack angles, but it is found insignificant to replace the baseline configuration i.e. plain fin and tube heat exchanger configuration without vortex generators. Moreover, in MOORA optimization analysis also, it is found that 5° attack angle provides the better thermal-hydraulic performance.

Cooperative Strategies to Develop Effective Stroke and Heart Attack Awareness Messages in Rural American Indian Communities, 2009–2010

PubMed Central

Gohdes, Dorothy; Fogle, Crystelle C.; Tadios, Fawn; Doore, Velva; Bell, Doreen S.; Harwell, Todd S.; Helgerson, Steven D.

2013-01-01

Introduction National initiatives to improve the recognition of heart attack and stroke warning signs have encouraged symptomatic people to seek early treatment, but few have shown significant effects in rural American Indian (AI) communities. Methods During 2009 and 2010, the Montana Cardiovascular Health Program, in collaboration with 2 tribal health departments, developed and conducted culturally specific public awareness campaigns for signs and symptoms of heart attack and stroke via local media. Telephone surveys were conducted before and after each campaign to evaluate the effectiveness of the campaigns. Results Knowledge of 3 or more heart attack warning signs and symptoms increased significantly on 1 reservation from 35% at baseline to 47% postcampaign. On the second reservation, recognition of 2 or more stroke signs and symptoms increased from 62% at baseline to 75% postcampaign, and the level of awareness remained at 73% approximately 4 months after the high-intensity campaign advertisements ended. Intent to call 9-1-1 did not increase in the heart attack campaign but did improve in the stroke campaign for specific symptoms. Recall of media campaigns on both reservations increased significantly from baseline to postcampaign for both media outlets (ie, radio and newspaper). Conclusion Carefully designed, culturally specific campaigns may help eliminate disparities in the recognition of heart attack and stroke warning signs in AI communities. PMID:23680509

Cooperative strategies to develop effective stroke and heart attack awareness messages in rural american Indian communities, 2009-2010.

PubMed

Oser, Carrie S; Gohdes, Dorothy; Fogle, Crystelle C; Tadios, Fawn; Doore, Velva; Bell, Doreen S; Harwell, Todd S; Helgerson, Steven D

2013-05-16

National initiatives to improve the recognition of heart attack and stroke warning signs have encouraged symptomatic people to seek early treatment, but few have shown significant effects in rural American Indian (AI) communities. During 2009 and 2010, the Montana Cardiovascular Health Program, in collaboration with 2 tribal health departments, developed and conducted culturally specific public awareness campaigns for signs and symptoms of heart attack and stroke via local media. Telephone surveys were conducted before and after each campaign to evaluate the effectiveness of the campaigns. Knowledge of 3 or more heart attack warning signs and symptoms increased significantly on 1 reservation from 35% at baseline to 47% postcampaign. On the second reservation, recognition of 2 or more stroke signs and symptoms increased from 62% at baseline to 75% postcampaign, and the level of awareness remained at 73% approximately 4 months after the high-intensity campaign advertisements ended. Intent to call 9-1-1 did not increase in the heart attack campaign but did improve in the stroke campaign for specific symptoms. Recall of media campaigns on both reservations increased significantly from baseline to postcampaign for both media outlets (ie, radio and newspaper). Carefully designed, culturally specific campaigns may help eliminate disparities in the recognition of heart attack and stroke warning signs in AI communities.

Using LTI Dynamics to Identify the Influential Nodes in a Network

PubMed Central

Jorswieck, Eduard; Scheunert, Christian

2016-01-01

Networks are used for modeling numerous technical, social or biological systems. In order to better understand the system dynamics, it is a matter of great interest to identify the most important nodes within the network. For a large set of problems, whether it is the optimal use of available resources, spreading information efficiently or even protection from malicious attacks, the most important node is the most influential spreader, the one that is capable of propagating information in the shortest time to a large portion of the network. Here we propose the Node Imposed Response (NiR), a measure which accurately evaluates node spreading power. It outperforms betweenness, degree, k-shell and h-index centrality in many cases and shows the similar accuracy to dynamics-sensitive centrality. We utilize the system-theoretic approach considering the network as a Linear Time-Invariant system. By observing the system response we can quantify the importance of each node. In addition, our study provides a robust tool set for various protective strategies. PMID:28030548

Inverse Problem in Self-assembly

NASA Astrophysics Data System (ADS)

Tkachenko, Alexei

2012-02-01

By decorating colloids and nanoparticles with DNA, one can introduce highly selective key-lock interactions between them. This leads to a new class of systems and problems in soft condensed matter physics. In particular, this opens a possibility to solve inverse problem in self-assembly: how to build an arbitrary desired structure with the bottom-up approach? I will present a theoretical and computational analysis of the hierarchical strategy in attacking this problem. It involves self-assembly of particular building blocks (``octopus particles''), that in turn would assemble into the target structure. On a conceptual level, our approach combines elements of three different brands of programmable self assembly: DNA nanotechnology, nanoparticle-DNA assemblies and patchy colloids. I will discuss the general design principles, theoretical and practical limitations of this approach, and illustrate them with our simulation results. Our crucial result is that not only it is possible to design a system that has a given nanostructure as a ground state, but one can also program and optimize the kinetic pathway for its self-assembly.

Spatial Pattern of Attacks of the Invasive Woodwasp Sirex noctilio, at Landscape and Stand Scales.

PubMed

Lantschner, M Victoria; Corley, Juan C

2015-01-01

Invasive insect pests are responsible for important damage to native and plantation forests, when population outbreaks occur. Understanding the spatial pattern of attacks by forest pest populations is essential to improve our understanding of insect population dynamics and for predicting attack risk by invasives or planning pest management strategies. The woodwasp Sirex noctilio is an invasive woodwasp that has become probably the most important pest of pine plantations in the Southern Hemisphere. Our aim was to study the spatial dynamics of S. noctilio populations in Southern Argentina. Specifically we describe: (1) the spatial patterns of S. noctilio outbreaks and their relation with environmental factors at a landscape scale; and (2) characterize the spatial pattern of attacked trees at the stand scale. We surveyed the spatial distribution of S. noctilio outbreaks in three pine plantation landscapes, and we assessed potential associations with topographic variables, habitat characteristics, and distance to other outbreaks. We also looked at the spatial distribution of attacked trees in 20 stands with different levels of infestation, and assessed the relationship of attacks with stand composition and management. We found that the spatial pattern of pine stands with S. noctilio outbreaks at the landscape scale is influenced mainly by the host species present, slope aspect, and distance to other outbreaks. At a stand scale, there is strong aggregation of attacked trees in stands with intermediate infestation levels, and the degree of attacks is influenced by host species and plantation management. We conclude that the pattern of S. noctilio damage at different spatial scales is influenced by a combination of both inherent population dynamics and the underlying patterns of environmental factors. Our results have important implications for the understanding and management of invasive insect outbreaks in forest systems.

Emotional and cognitive changes during and post a near fatal heart attack and one-year after: a case study.

PubMed

Lane, Andrew M; Godfrey, Richard

2010-01-01

This case study reports on changes in emotions before and during an unexpected heart rate in a young, apparently healthy male with a life-long history of exercise in the absence of family history of heart problems. He completed the Brunel Mood Scale (Terry et al. , 2003) to assess emotions before, during, and after the heart attack, and also describing his thoughts during these periods. Results indicate he experienced unpleasant emotions in the build up to the heart attack, feelings he attributed at the time to frustration to achieve fitness goals. He maintained an exercise regime prior to having a heart attack, a finding consistent with previous research suggesting that early diagnosis, although vital for survival, is not likely to be identified among seemingly healthy individuals. During the heart attack, he experienced a rapid emotional change characterised by a rapid increase in anger coupled with thoughts of needing to survive. The intensity of emotions and regulation strategies employed before and during the heart attack provide insight this experience, and we suggest future research should investigate emotional change during adverse conditions. Key pointsThe present case study details emotions experienced and attempts to regulate these emotions before, during and post a heart attack. Unpleasant emotions experienced before the heart were attributed to lack of progress toward fitness goals, a perception that is plausible as he was a regular exerciser.Early identification of heart attack is critical as "Time is Muscle" (Whyte et al., 2009) and therefore even people perceived to be at low risk should consider the possibility of such an eventuality, and seek medical treatment early in the process.

Flight Test Validation of Optimal Input Design and Comparison to Conventional Inputs

NASA Technical Reports Server (NTRS)

Morelli, Eugene A.

1997-01-01

A technique for designing optimal inputs for aerodynamic parameter estimation was flight tested on the F-18 High Angle of Attack Research Vehicle (HARV). Model parameter accuracies calculated from flight test data were compared on an equal basis for optimal input designs and conventional inputs at the same flight condition. In spite of errors in the a priori input design models and distortions of the input form by the feedback control system, the optimal inputs increased estimated parameter accuracies compared to conventional 3-2-1-1 and doublet inputs. In addition, the tests using optimal input designs demonstrated enhanced design flexibility, allowing the optimal input design technique to use a larger input amplitude to achieve further increases in estimated parameter accuracy without departing from the desired flight test condition. This work validated the analysis used to develop the optimal input designs, and demonstrated the feasibility and practical utility of the optimal input design technique.

A taxonomy and discussion of software attack technologies

NASA Astrophysics Data System (ADS)

Banks, Sheila B.; Stytz, Martin R.

2005-03-01

Software is a complex thing. It is not an engineering artifact that springs forth from a design by simply following software coding rules; creativity and the human element are at the heart of the process. Software development is part science, part art, and part craft. Design, architecture, and coding are equally important activities and in each of these activities, errors may be introduced that lead to security vulnerabilities. Therefore, inevitably, errors enter into the code. Some of these errors are discovered during testing; however, some are not. The best way to find security errors, whether they are introduced as part of the architecture development effort or coding effort, is to automate the security testing process to the maximum extent possible and add this class of tools to the tools available, which aids in the compilation process, testing, test analysis, and software distribution. Recent technological advances, improvements in computer-generated forces (CGFs), and results in research in information assurance and software protection indicate that we can build a semi-intelligent software security testing tool. However, before we can undertake the security testing automation effort, we must understand the scope of the required testing, the security failures that need to be uncovered during testing, and the characteristics of the failures. Therefore, we undertook the research reported in the paper, which is the development of a taxonomy and a discussion of software attacks generated from the point of view of the security tester with the goal of using the taxonomy to guide the development of the knowledge base for the automated security testing tool. The representation for attacks and threat cases yielded by this research captures the strategies, tactics, and other considerations that come into play during the planning and execution of attacks upon application software. The paper is organized as follows. Section one contains an introduction to our research and a discussion of the motivation for our work. Section two contains a presents our taxonomy of software attacks and a discussion of the strategies employed and general weaknesses exploited for each attack. Section three contains a summary and suggestions for further research.

Rocket ascent G-limited moment-balanced optimization program (RAGMOP)

NASA Technical Reports Server (NTRS)

Lyons, J. T.; Woltosz, W. S.; Abercrombie, G. E.; Gottlieb, R. G.

1972-01-01

This document describes the RAGMOP (Rocket Ascent G-limited Momentbalanced Optimization Program) computer program for parametric ascent trajectory optimization. RAGMOP computes optimum polynomial-form attitude control histories, launch azimuth, engine burn-time, and gross liftoff weight for space shuttle type vehicles using a search-accelerated, gradient projection parameter optimization technique. The trajectory model available in RAGMOP includes a rotating oblate earth model, the option of input wind tables, discrete and/or continuous throttling for the purposes of limiting the thrust acceleration and/or the maximum dynamic pressure, limitation of the structural load indicators (the product of dynamic pressure with angle-of-attack and sideslip angle), and a wide selection of intermediate and terminal equality constraints.

Neural Network Prediction of New Aircraft Design Coefficients

NASA Technical Reports Server (NTRS)

Norgaard, Magnus; Jorgensen, Charles C.; Ross, James C.

1997-01-01

This paper discusses a neural network tool for more effective aircraft design evaluations during wind tunnel tests. Using a hybrid neural network optimization method, we have produced fast and reliable predictions of aerodynamical coefficients, found optimal flap settings, and flap schedules. For validation, the tool was tested on a 55% scale model of the USAF/NASA Subsonic High Alpha Research Concept aircraft (SHARC). Four different networks were trained to predict coefficients of lift, drag, moment of inertia, and lift drag ratio (C(sub L), C(sub D), C(sub M), and L/D) from angle of attack and flap settings. The latter network was then used to determine an overall optimal flap setting and for finding optimal flap schedules.

Drug discovery: Fighting evolution with chemical synthesis

NASA Astrophysics Data System (ADS)

Yan, Ming; Baran, Phil S.

2016-05-01

A synthetic strategy has been developed that provides easy access to structurally diverse analogues of naturally occurring antibiotics, providing a fresh means of attack in the war against drug-resistant bacteria. See Article p.338

Home and Clinical Cardiovascular Care Center (H4C): a Framework for Integrating Body Sensor Networks and QTRU Cryptography System.

PubMed

Zakerolhosseini, Ali; Sokouti, Massoud; Pezeshkian, Massoud

2013-01-01

Quick responds to heart attack patients before arriving to hospital is a very important factor. In this paper, a combined model of Body Sensor Network and Personal Digital Access using QTRU cipher algorithm in Wifi networks is presented to efficiently overcome these life threatening attacks. The algorithm for optimizing the routing paths between sensor nodes and an algorithm for reducing the power consumption are also applied for achieving the best performance by this model. This system is consumes low power and has encrypting and decrypting processes. It also has an efficient routing path in a fast manner.

Home and Clinical Cardiovascular Care Center (H4C): a Framework for Integrating Body Sensor Networks and QTRU Cryptography System

PubMed Central

Zakerolhosseini, Ali; Sokouti, Massoud; Pezeshkian, Massoud

2013-01-01

Quick responds to heart attack patients before arriving to hospital is a very important factor. In this paper, a combined model of Body Sensor Network and Personal Digital Access using QTRU cipher algorithm in Wifi networks is presented to efficiently overcome these life threatening attacks. The algorithm for optimizing the routing paths between sensor nodes and an algorithm for reducing the power consumption are also applied for achieving the best performance by this model. This system is consumes low power and has encrypting and decrypting processes. It also has an efficient routing path in a fast manner. PMID:24252988

Optimization of Cholinesterase-Based Catalytic Bioscavengers Against Organophosphorus Agents.

PubMed

Lushchekina, Sofya V; Schopfer, Lawrence M; Grigorenko, Bella L; Nemukhin, Alexander V; Varfolomeev, Sergei D; Lockridge, Oksana; Masson, Patrick

2018-01-01

Organophosphorus agents (OPs) are irreversible inhibitors of acetylcholinesterase (AChE). OP poisoning causes major cholinergic syndrome. Current medical counter-measures mitigate the acute effects but have limited action against OP-induced brain damage. Bioscavengers are appealing alternative therapeutic approach because they neutralize OPs in bloodstream before they reach physiological targets. First generation bioscavengers are stoichiometric bioscavengers. However, stoichiometric neutralization requires administration of huge doses of enzyme. Second generation bioscavengers are catalytic bioscavengers capable of detoxifying OPs with a turnover. High bimolecular rate constants ( k cat / K m > 10 6 M -1 min -1 ) are required, so that low enzyme doses can be administered. Cholinesterases (ChE) are attractive candidates because OPs are hemi-substrates. Moderate OP hydrolase (OPase) activity has been observed for certain natural ChEs and for G117H-based human BChE mutants made by site-directed mutagenesis. However, before mutated ChEs can become operational catalytic bioscavengers their dephosphylation rate constant must be increased by several orders of magnitude. New strategies for converting ChEs into fast OPase are based either on combinational approaches or on computer redesign of enzyme. The keystone for rational conversion of ChEs into OPases is to understand the reaction mechanisms with OPs. In the present work we propose that efficient OP hydrolysis can be achieved by re-designing the configuration of enzyme active center residues and by creating specific routes for attack of water molecules and proton transfer. Four directions for nucleophilic attack of water on phosphorus atom were defined. Changes must lead to a novel enzyme, wherein OP hydrolysis wins over competing aging reactions. Kinetic, crystallographic, and computational data have been accumulated that describe mechanisms of reactions involving ChEs. From these studies, it appears that introducing new groups that create a stable H-bonded network susceptible to activate and orient water molecule, stabilize transition states (TS), and intermediates may determine whether dephosphylation is favored over aging. Mutations on key residues (L286, F329, F398) were considered. QM/MM calculations suggest that mutation L286H combined to other mutations favors water attack from apical position. However, the aging reaction is competing. Axial direction of water attack is not favorable to aging. QM/MM calculation shows that F329H+F398H-based multiple mutants display favorable energy barrier for fast reactivation without aging.

Cyber secure systems approach for NPP digital control systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCreary, T. J.; Hsu, A.

2006-07-01

Whether fossil or nuclear power, the chief operations goal is to generate electricity. The heart of most plant operations is the I and C system. With the march towards open architecture, the I and C system is more vulnerable than ever to system security attacks (denial of service, virus attacks and others), thus jeopardizing plant operations. Plant staff must spend large amounts of time and money setting up and monitoring a variety of security strategies to counter the threats and actual attacks to the system. This time and money is a drain on the financial performance of a plant andmore » distracts valuable operations resources from their real goals: product. The pendulum towards complete open architecture may have swung too far. Not all aspects of proprietary hardware and software are necessarily 'bad'. As the aging U.S. fleet of nuclear power plants starts to engage in replacing legacy control systems, and given the on-going (and legitimate) concern about the security of present digital control systems, decisions about how best to approach cyber security are vital to the specification and selection of control system vendors for these upgrades. The authors maintain that utilizing certain resources available in today's digital technology, plant control systems can be configured from the onset to be inherently safe, so that plant staff can concentrate on the operational issues of the plant. The authors postulate the concept of the plant I and C being bounded in a 'Cyber Security Zone' and present a design approach that can alleviate the concern and cost at the plant level of dealing with system security strategies. Present approaches through various IT cyber strategies, commercial software, and even postulated standards from various industry/trade organizations are almost entirely reactive and simply add to cost and complexity. This Cyber Security Zone design demonstrates protection from the four classes of cyber security attacks: 1)Threat from an intruder attempting to disrupt network communications by entering the system from an attached utility network or utilizing a modem connected to a control system PC that is in turn connected to a publicly accessible phone; 2)Threat from a user connecting an unauthorized computer to the control network; 3)Threat from a security attack when an unauthorized user gains access to a PC connected to the plant network;. 4)Threat from internal disruption (by plant staff, whether, malicious or otherwise) by unauthorized usage of files or file handling media that opens the system to security threat (as typified in current situation in most control rooms). The plant I and C system cyber security design and the plant specific procedures should adequately demonstrate protection from the four pertinent classes of cyber security attacks. The combination of these features should demonstrate that the system is not vulnerable to any analyzed cyber security attacks either from internal sources or through network connections. The authors will provide configurations that will demonstrate the Cyber Security Zone. (authors)« less

National Aviation Security Policy, Strategy, and Mode-Specific Plans: Background and Considerations for Congress

DTIC Science & Technology

2008-01-02

aviation security . The approach to aviation security was largely shaped by past events, such as the bombing of Pan Am flight 103 in December 1988, rather...2001 attacks, U.S. aviation security policy and strategy was closely linked to the changes called for in the Aviation and Transportation Security Act...sensitive thus limiting public discourse on the DHS strategy for aviation security . However, in June 2006 President Bush directed the DHS to establish and

Optimism, coping and long-term recovery from coronary artery surgery in women.

PubMed

King, K B; Rowe, M A; Kimble, L P; Zerwic, J J

1998-02-01

Optimism, coping strategies, and psychological and functional outcomes were measured in 55 women undergoing coronary artery surgery. Data were collected in-hospital and at 1, 6, and 12 months after surgery. Optimism was related to positive moods and life satisfaction, and inversely related to negative moods. Few relationships were found between optimism and functional ability. Cognitive coping strategies accounted for a mediating effect between optimism and negative mood. Optimists were more likely to accept their situation, and less likely to use escapism. In turn, these coping strategies were inversely related to negative mood and mediated the relationship between optimism and this outcome. Optimism was not related to problem-focused coping strategies; this, these coping strategies cannot explain the relationship between optimism and outcomes.

Inducible defense against pathogens and parasites: optimal choice among multiple options.

PubMed

Shudo, E; Iwasa, Y

2001-03-21

Defense against pathogen, parasites and herbivores is often enhanced after their invasion into the host's body. Sometimes different options are adopted depending on the identity and the quantity of the pathogen, exemplified by the switch between Th1 and Th2 systems in mammalian immunity. In this paper, we study the optimal defense of the host when two alternative responses are available, which differ in the effectiveness of suppressing the growth of pathogen (parasite, or herbivore), the damage to the host caused by the defense response, and the magnitude of time delay before the defense response becomes fully effective. The optimal defense is the one that minimizes the sum of the damages caused by the pathogen and the cost due to defense activities. The damage by pathogens increases in proportion to the time integral of the pathogen abundance, and the cost is proportional to the defense activity. We can prove that a single globally optimal combination of defense options always exists and there is no other local optimum. Depending on the parameters, the optimal is to adopt only the early response, only the late response, or both responses. The defense response with a shorter time delay is more heavily used when the pathogen grows fast, the initial pathogen abundance is large, and the difference in time delay is long. We also study the host's optimal choice between constitutive and inducible defenses. In the constitutive defense, the response to pathogen attack works without delay, but it causes the cost even when the pathogen attack does not occur. We discuss mammalian immunity and the plant chemical defense from the model's viewpoint. Copyright 2001 Academic Press.

Predictors of influenza vaccination uptake among adults with a history of heart attack.

PubMed

Jiménez-García, Rodrigo; Hernández-Barrera, Valentín; de Andres, Ana Lopez; Jimenez-Trujillo, Isabel; Esteban, Jesus; Gil, Angel; Carrasco-Garrido, Pilar

2010-07-01

Influenza vaccination can reduce morbidity and mortality caused by cardiovascular diseases. This study sought to evaluate influenza vaccination coverage among adults with a history of heart attack and to determine which variables were associated with vaccine uptake. A total of 716 adults reported having suffered a heart attack. The coverage among sufferers was 67.9% as against 35% for non sufferers. The variables that were significantly associated with a higher likelihood of receiving the vaccine among sufferers were: higher age; male gender, no smoking habit, "Physician visits in the preceding four weeks"; and, "Blood pressure control in the preceding three months". A descriptive study was conducted using individual data from adults aged ≥40 years included in the year 2006/7 Spanish Health Survey and comparing subjects with a history of heart attack with those who had not suffered this event. The number of participants surveyed was 20,060. Subjects were classified as heart attack sufferers if they answered affirmatively to the question: "Has your doctor told you that you have suffered a heart attack?" To assess influenza vaccination status we considered the response to the question, "Did you have a 'flu shot in the latest campaign?". Independent variables included sociodemographic, health-related, lifestyles and periodic control of cardiovascular risk factors. Influenza vaccination coverage among subjects who have suffered a heart attack is below desirable levels. Multiple strategies focused on providers and patients are needed to improve influenza vaccination coverage among these high risk subjects, particularly now with the emerging H1N1 pandemic.

Impediments to the success of management actions for species recovery.

PubMed

Ng, Chooi Fei; Possingham, Hugh P; McAlpine, Clive A; de Villiers, Deidré L; Preece, Harriet J; Rhodes, Jonathan R

2014-01-01

Finding cost-effective management strategies to recover species declining due to multiple threats is challenging, especially when there are limited resources. Recent studies offer insights into how costs and threats can influence the best choice of management actions. However, when implementing management actions in the real-world, a range of impediments to management success often exist that can be driven by social, technological and land-use factors. These impediments may limit the extent to which we can achieve recovery objectives and influence the optimal choice of management actions. Nonetheless, the implications of these impediments are not well understood, especially for recovery planning involving multiple actions. We used decision theory to assess the impact of these types of impediments for allocating resources among recovery actions to mitigate multiple threats. We applied this to a declining koala (Phascolarctos cinereus) population threatened by habitat loss, vehicle collisions, dog attacks and disease. We found that the unwillingness of dog owners to restrain their dogs at night (a social impediment), the effectiveness of wildlife crossings to reduce vehicle collisions (a technological impediment) and the unavailability of areas for restoration (a land-use impediment) significantly reduced the effectiveness of our actions. In the presence of these impediments, achieving successful recovery may be unlikely. Further, these impediments influenced the optimal choice of recovery actions, but the extent to which this was true depended on the target koala population growth rate. Given that species recovery is an important strategy for preserving biodiversity, it is critical that we consider how impediments to the success of recovery actions modify our choice of actions. In some cases, it may also be worth considering whether investing in reducing or removing impediments may be a cost-effective course of action.

Explaining the unexplainable: designing a national strategy on classroom communication concerning the 22 July terror attack in Norway

PubMed Central

Schultz, Jon-Håkon; Langballe, Åse; Raundalen, Magne

2014-01-01

Background In the context of crisis and disasters, school-aged children are a vulnerable group with fewer coping resources than adults. The school is a key arena for preventive interventions; teachers can be given a key role in large-scale school-based interventions following a man-made or natural disaster. Objectives This paper describes a practical example of designing a school-based population-level intervention. Methods The preventive measures were delivered as a national communication strategy between teachers and pupils aged 6–19 concerning the terror attack on 22 July 2011 in Norway. The strategy is based on principles from international research. Results The presentation contributes to the discussion of defining the teacher's role in school-based crisis interventions and dealing with high-intensity media coverage of war, terror, and catastrophes. Conclusions The presentation provides educational and psychological perspectives on how teachers can take an active role in helping pupils to deal with such events through two approaches: the therapeutic approach, to restore calm and feelings of safety; and the educational approach, to foster reflection and deeper understanding. PMID:25018859

Explaining the unexplainable: designing a national strategy on classroom communication concerning the 22 July terror attack in Norway.

PubMed

Schultz, Jon-Håkon; Langballe, Ase; Raundalen, Magne

2014-01-01

In the context of crisis and disasters, school-aged children are a vulnerable group with fewer coping resources than adults. The school is a key arena for preventive interventions; teachers can be given a key role in large-scale school-based interventions following a man-made or natural disaster. This paper describes a practical example of designing a school-based population-level intervention. The preventive measures were delivered as a national communication strategy between teachers and pupils aged 6-19 concerning the terror attack on 22 July 2011 in Norway. The strategy is based on principles from international research. The presentation contributes to the discussion of defining the teacher's role in school-based crisis interventions and dealing with high-intensity media coverage of war, terror, and catastrophes. THE PRESENTATION PROVIDES EDUCATIONAL AND PSYCHOLOGICAL PERSPECTIVES ON HOW TEACHERS CAN TAKE AN ACTIVE ROLE IN HELPING PUPILS TO DEAL WITH SUCH EVENTS THROUGH TWO APPROACHES: the therapeutic approach, to restore calm and feelings of safety; and the educational approach, to foster reflection and deeper understanding.

Coping strategies as mediators of the relationship between sense of coherence and stress reactions: Israeli adolescents under missile attacks.

PubMed

Braun-Lewensohn, Orna; Sagy, Shifra; Roth, Guy

2011-05-01

This study aimed to explore the relationships between sense of coherence (SOC) and stress reactions as mediated by cognitive appraisal and coping strategies among adolescents facing the acute stressful situation of missile attacks. Employing the Salutogenic Model and the interactionist approach to coping, we asked what the roles of situational factors such as coping strategies and cognitive appraisal were in mediating the relationship between SOC and stress reactions. Data were gathered during January 2009 when hundreds of missiles fell in southern Israel. One hundred and thirty eight adolescents filled out questionnaires dealing with SOC, cognitive appraisal (endangerment feelings), Adolescent Coping Scale, state anxiety, state anger, and psychological distress. Overall, our model explained 55% of the variance in stress reactions. SOC had the strongest total direct and indirect effects. Previous findings have indicated SOC as playing only a limited role in explaining stress reactions in acute stress situations. The results of this study highlight the potential of SOC as a powerful resilience factor even in an acute situation, through mediation of situational factors.

A Bernoulli Gaussian Watermark for Detecting Integrity Attacks in Control Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weerakkody, Sean; Ozel, Omur; Sinopoli, Bruno

We examine the merit of Bernoulli packet drops in actively detecting integrity attacks on control systems. The aim is to detect an adversary who delivers fake sensor measurements to a system operator in order to conceal their effect on the plant. Physical watermarks, or noisy additive Gaussian inputs, have been previously used to detect several classes of integrity attacks in control systems. In this paper, we consider the analysis and design of Gaussian physical watermarks in the presence of packet drops at the control input. On one hand, this enables analysis in a more general network setting. On the othermore » hand, we observe that in certain cases, Bernoulli packet drops can improve detection performance relative to a purely Gaussian watermark. This motivates the joint design of a Bernoulli-Gaussian watermark which incorporates both an additive Gaussian input and a Bernoulli drop process. We characterize the effect of such a watermark on system performance as well as attack detectability in two separate design scenarios. Here, we consider a correlation detector for attack recognition. We then propose efficiently solvable optimization problems to intelligently select parameters of the Gaussian input and the Bernoulli drop process while addressing security and performance trade-offs. Finally, we provide numerical results which illustrate that a watermark with packet drops can indeed outperform a Gaussian watermark.« less

Event-triggered distributed filtering over sensor networks with deception attacks and partial measurements

NASA Astrophysics Data System (ADS)

Bu, Xianye; Dong, Hongli; Han, Fei; Li, Gongfa

2018-07-01

This paper is concerned with the distributed filtering problem for a class of time-varying systems subject to deception attacks and event-triggering protocols. Due to the bandwidth limitation, an event-triggered communication strategy is adopted to alleviate the data transmission pressure in the algorithm implementation process. The partial nodes-based filtering problem is considered, where only a partial of nodes can measure the information of the plant. Meanwhile, the measurement information possibly suffers the deception attacks in the transmission process. Sufficient conditions can be established such that the error dynamics satisfies the prescribed average ? performance constraints. The parameters of designed filters can be calculated by solving a series of recursive linear matrix inequalities. A simulation example is presented to demonstrate the effectiveness of the proposed filtering method in this paper.

Cryptanalysis and security enhancement of optical cryptography based on computational ghost imaging

NASA Astrophysics Data System (ADS)

Yuan, Sheng; Yao, Jianbin; Liu, Xuemei; Zhou, Xin; Li, Zhongyang

2016-04-01

Optical cryptography based on computational ghost imaging (CGI) has attracted much attention of researchers because it encrypts plaintext into a random intensity vector rather than complexed-valued function. This promising feature of the CGI-based cryptography reduces the amount of data to be transmitted and stored and therefore brings convenience in practice. However, we find that this cryptography is vulnerable to chosen-plaintext attack because of the linear relationship between the input and output of the encryption system, and three feasible strategies are proposed to break it in this paper. Even though a large number of plaintexts need to be chosen in these attack methods, it means that this cryptography still exists security risks. To avoid these attacks, a security enhancement method utilizing an invertible matrix modulation is further discussed and the feasibility is verified by numerical simulations.

The role of revenge, denial, and terrorism distress in restoring just world beliefs: the impact of the 2008 Mumbai attacks on British and Indian students.

PubMed

Ferguson, Neil; Kamble, Shanmukh V

2012-01-01

Just world beliefs for students (N = 413) from India and the United Kingdom were measured. The participants then read a scenario about the 2008 terrorist attacks on Mumbai. The participants were then assessed for terrorism distress and offered multiple strategies (revenge and denial) to restore their just world beliefs. The findings indicate that students resident in India along with those who hold strong just world beliefs felt more distress, held a greater desire for revenge, and demonstrated more denial than the British students and those who had weak beliefs in a just world. These results indicate the important role just world beliefs play in responding to the threat created by mass casualty terrorist attacks. The implications for just world theory are also discussed.

Trophic strategies, animal diversity and body size

USGS Publications Warehouse

Lafferty, Kevin D.; Kuris, Armand M.

2002-01-01

A primary difference between predators and parasites is the number of victims that an individual attacks throughout a life-history stage. A key division within natural enemies is whether a successful attack eliminates the fitness of the prey or the host. A third distinctive axis for parasites is whether the host must die to further parasite development. The presence or absence of intensity-dependent pathology is a fourth factor that separates macroparasites from microparasites; this also distinguishes between social and solitary predators. Combining these four dichotomies defines seven types of parasitism, seven corresponding parasites, three forms of predation and, when one considers obligate and facultative combinations of these forms, four types of predator. Here, we argue that the energetics underlying the relative and absolute sizes of natural enemies and their victims is the primary selective factor responsible for the evolution of these different trophic strategies.

Security solutions: strategy and architecture

NASA Astrophysics Data System (ADS)

Seto, Myron W. L.

2002-04-01

Producers of banknotes, other documents of value and brand name goods are being presented constantly with new challenges due to the ever increasing sophistication of easily-accessible desktop publishing and color copying machines, which can be used for counterfeiting. Large crime syndicates have also shown that they have the means and the willingness to invest large sums of money to mimic security features. To ensure sufficient and appropriate protection, a coherent security strategy has to be put into place. The feature has to be appropriately geared to fight against the different types of attacks and attackers, and to have the right degree of sophistication or ease of authentication depending upon by whom or where a check is made. Furthermore, the degree of protection can be considerably increased by taking a multi-layered approach and using an open platform architecture. Features can be stratified to encompass overt, semi-covert, covert and forensic features.

A two-dimensional air-to-air combat game - Toward an air-combat advisory system

NASA Technical Reports Server (NTRS)

Neuman, Frank

1987-01-01

Air-to-air combat is modeled as a discrete differential game, and by constraining the game to searching for the best guidance laws from the sets of those considered for each opponent, feedback and outcome charts are obtained which can be used to turn one of the automatic opponents into an intelligent opponent against a human pilot. A one-on-one two-dimensional fully automatic, or manned versus automatic, air-to-air combat game has been designed which includes both attack and evasion alternatives for both aircraft. Guidance law selection occurs by flooding the initial-condition space with four simulated fights for each initial condition, depicting the various attack/evasion strategies for the two opponents, and recording the outcomes. For each initial condition, the minimax method from differential games is employed to determine the best choice from the available strategies.

Cyber / Physical Security Vulnerability Assessment Integration

DOE Office of Scientific and Technical Information (OSTI.GOV)

MacDonald, Douglas G.; Simpkins, Bret E.

Abstract Both physical protection and cyber security domains offer solutions for the discovery of vulnerabilities through the use of various assessment processes and software tools. Each vulnerability assessment (VA) methodology provides the ability to identify and categorize vulnerabilities, and quantifies the risks within their own areas of expertise. Neither approach fully represents the true potential security risk to a site and/or a facility, nor comprehensively assesses the overall security posture. The technical approach to solving this problem was to identify methodologies and processes that blend the physical and cyber security assessments, and develop tools to accurately quantify the unaccounted formore » risk. SMEs from both the physical and the cyber security domains developed the blending methodologies, and cross trained each other on the various aspects of the physical and cyber security assessment processes. A local critical infrastructure entity volunteered to host a proof of concept physical/cyber security assessment, and the lessons learned have been leveraged by this effort. The four potential modes of attack an adversary can use in approaching a target are; Physical Only Attack, Cyber Only Attack, Physical Enabled Cyber Attack, and the Cyber Enabled Physical Attack. The Physical Only and the Cyber Only pathway analysis are two of the most widely analyzed attack modes. The pathway from an off-site location to the desired target location is dissected to ensure adversarial activity can be detected and neutralized by the protection strategy, prior to completion of a predefined task. This methodology typically explores a one way attack from the public space (or common area) inward towards the target. The Physical Enabled Cyber Attack and the Cyber Enabled Physical Attack are much more intricate. Both scenarios involve beginning in one domain to affect change in the other, then backing outward to take advantage of the reduced system effectiveness, before penetrating further into the defenses. The proper identification and assessment of the overlapping areas (and interaction between these areas) in the VA process is necessary to accurately assess the true risk.« less

Improving the management and referral of patients with transient ischaemic attacks: a change strategy for a health community.

PubMed

Wright, J; Harrison, S; McGeorge, M; Patterson, C; Russell, I; Russell, D; Small, N; Taylor, M; Walsh, M; Warren, E; Young, J

2006-02-01

Rapid referral and management of patients with transient ischaemic attacks is a key component in the national strategy for stroke prevention. However, patients with transient ischaemic attacks are poorly identified and undertreated. Before and after evaluation of quality improvement programme with controlled comparison in three primary care trusts reflecting diverse populations and organisational structures in an urban district in the North of England. The proportion of patients receiving antiplatelet drugs and safe driving advice on referral to a specialty clinic, and the numbers of referrals, adjusted for age, to the specialist clinic before and after the improvement programme. Interviews with patient and professionals to identify gaps and barriers to good practice; development of evidence based guidelines for the management of patients with transient ischaemic attacks; interactive multidisciplinary workshops for each primary care trust with feedback of individual audit results of referral practice; outreach visits to teams who were unable to attend the workshops; referral templates and desktop summaries to provide reminders of the guidelines to clinicians; incorporation of standards into professional contracts. A significant improvement occurred in identification and referral of patients with transient ischaemic attacks to specialist clinics, with a 41% increase in referrals from trained practices compared with control practices. There were also significant improvements in the early treatment and safety advice provided to patients before referral. A strategic approach to effective quality improvement across a diverse health community is feasible and achievable. Careful planning with patient and professional involvement to develop a tailored and multifaceted quality improvement programme to implement evidence based practice can work in very different primary care settings. Key components of the effectiveness of the model include contextual analysis, strong professional support, clear recommendations based on robust evidence, simplicity of adoption, good communication, and use of established networks and opinion leaders.

Fuzzy-information-based robustness of interconnected networks against attacks and failures

NASA Astrophysics Data System (ADS)

Zhu, Qian; Zhu, Zhiliang; Wang, Yifan; Yu, Hai

2016-09-01

Cascading failure is fatal in applications and its investigation is essential and therefore became a focal topic in the field of complex networks in the last decade. In this paper, a cascading failure model is established for interconnected networks and the associated data-packet transport problem is discussed. A distinguished feature of the new model is its utilization of fuzzy information in resisting uncertain failures and malicious attacks. We numerically find that the giant component of the network after failures increases with tolerance parameter for any coupling preference and attacking ambiguity. Moreover, considering the effect of the coupling probability on the robustness of the networks, we find that the robustness of the assortative coupling and random coupling of the network model increases with the coupling probability. However, for disassortative coupling, there exists a critical phenomenon for coupling probability. In addition, a critical value that attacking information accuracy affects the network robustness is observed. Finally, as a practical example, the interconnected AS-level Internet in South Korea and Japan is analyzed. The actual data validates the theoretical model and analytic results. This paper thus provides some guidelines for preventing cascading failures in the design of architecture and optimization of real-world interconnected networks.

Attack on Lignified Grass Cell Walls by a Facultatively Anaerobic Bacterium

PubMed Central

Akin, Danny E.

1980-01-01

A filamentous, facultatively anaerobic microorganism that attacked lignified tissue in forage grasses was isolated from rumen fluid with a Bermuda grass-containing anaerobic medium in roll tubes. The microbe, designated 7-1, demonstrated various colony and cellular morphologies under different growth conditions. Scanning electron microscopy revealed that 7-1 attacked lignified cell walls in aerobic and anaerobic culture. 7-1 predominately degraded tissues reacting positively for lignin with the chlorine-sulfite stain (i.e., sclerenchyma in leaf blades and parenchyma in stems) rather than the more resistant acid phloroglucinol-positive tissues (i.e., lignified vascular tissue and sclerenchyma ring in stems), although the latter tissues were occasionally attacked. Turbidimetric tests showed that 7-1 in anaerobic culture grew optimally at 39°C at a pH of 7.4 to 8.0. Tests for growth on plant cell wall carbohydrates showed that 7-1 grew on xylan and pectin slowly in aerobic cultures but not with pectin and only slightly with xylan in anaerobic culture. 7-1 was noncellulolytic as shown by filter paper tests. The microbe used the phenolic acids sinapic, ferulic, and p-coumaric acids as substrates for growth; the more highly methoxylated acids were used more effectively. Images PMID:16345651

Hedging against terrorism: Are US businesses prepared?

PubMed

Kahan, Jerome H

2015-01-01

Private US companies face risks in connection with financial matters, but are not necessarily prepared to cope with risks that can seriously disrupt or even halt their operations, notably terrorist attacks and natural disasters. Enhancing the resilience of businesses when dealing with terrorism is especially challenging, as these groups or individuals can adapt tactics to exploit the vulnerabilities of companies they wish to target. Business managers need to formulate flexible preparedness plans that reduce risks from large-scale natural disasters as well as terrorist attacks. In doing so, they can take advantage of post-9/11 US government guidance for these endeavours as well as programmes that eliminate risks to private insurance entities so they can issue policies that cover terrorist strikes of high consequences. Just as business executives use hedging strategies in the world of finance, they also need operational hedging strategies as a means of exploiting as well as lowering the risks surrounding future uncertainties. Resources devoted to planning and hedging are investments that can increase the odds of businesses surviving and thriving, even if they experience high-impact terrorist attacks, threats or large-scale natural disasters, making suppliers, customers and stakeholders happy. The purpose of this paper is to give executives the incentive to take steps to do just that.

Cotton defense induction patterns under spatially, temporally and quantitatively varying herbivory levels

USDA-ARS?s Scientific Manuscript database

The optimal defense theory (ODT) predicts that plants allocate defense compounds to their tissues depending on its value and the likelihood of herbivore attack. Whereas ODT has been confirmed for static damage levels it remains poorly understood if ODT holds true for defense organization of inducibl...

Essential Web Sites to Research the Globalization Process

ERIC Educational Resources Information Center

Scott, Thomas J.; O'Sullivan, Michael

2002-01-01

The terrorist attacks of September 11, 2001, brought a stark reality to social studies classrooms throughout the United States. Globalism and the expansion of world trade relations created optimism about enhanced cultural understanding, peace, and economic prosperity. However, it is clear that globalization also has a dark side. Suddenly…

Correlations and forecast of death tolls in the Syrian conflict.

PubMed

Fujita, Kazuki; Shinomoto, Shigeru; Rocha, Luis E C

2017-11-16

The Syrian armed conflict has been ongoing since 2011 and has already caused thousands of deaths. The analysis of death tolls helps to understand the dynamics of the conflict and to better allocate resources and aid to the affected areas. In this article, we use information on the daily number of deaths to study temporal and spatial correlations in the data, and exploit this information to forecast events of deaths. We found that the number of violent deaths per day in Syria varies more widely than that in England in which non-violent deaths dominate. We have identified strong positive auto-correlations in Syrian cities and non-trivial cross-correlations across some of them. The results indicate synchronization in the number of deaths at different times and locations, suggesting respectively that local attacks are followed by more attacks at subsequent days and that coordinated attacks may also take place across different locations. Thus the analysis of high temporal resolution data across multiple cities makes it possible to infer attack strategies, warn potential occurrence of future events, and hopefully avoid further deaths.

A Game-Theoretic Response Strategy for Coordinator Attack in Wireless Sensor Networks

PubMed Central

Liu, Jianhua; Yue, Guangxue; Shang, Huiliang; Li, Hongjie

2014-01-01

The coordinator is a specific node that controls the whole network and has a significant impact on the performance in cooperative multihop ZigBee wireless sensor networks (ZWSNs). However, the malicious node attacks coordinator nodes in an effort to waste the resources and disrupt the operation of the network. Attacking leads to a failure of one round of communication between the source nodes and destination nodes. Coordinator selection is a technique that can considerably defend against attack and reduce the data delivery delay, and increase network performance of cooperative communications. In this paper, we propose an adaptive coordinator selection algorithm using game and fuzzy logic aiming at both minimizing the average number of hops and maximizing network lifetime. The proposed game model consists of two interrelated formulations: a stochastic game for dynamic defense and a best response policy using evolutionary game formulation for coordinator selection. The stable equilibrium best policy to response defense is obtained from this game model. It is shown that the proposed scheme can improve reliability and save energy during the network lifetime with respect to security. PMID:25105171

A game-theoretic response strategy for coordinator attack in wireless sensor networks.

PubMed

Liu, Jianhua; Yue, Guangxue; Shen, Shigen; Shang, Huiliang; Li, Hongjie

2014-01-01

The coordinator is a specific node that controls the whole network and has a significant impact on the performance in cooperative multihop ZigBee wireless sensor networks (ZWSNs). However, the malicious node attacks coordinator nodes in an effort to waste the resources and disrupt the operation of the network. Attacking leads to a failure of one round of communication between the source nodes and destination nodes. Coordinator selection is a technique that can considerably defend against attack and reduce the data delivery delay, and increase network performance of cooperative communications. In this paper, we propose an adaptive coordinator selection algorithm using game and fuzzy logic aiming at both minimizing the average number of hops and maximizing network lifetime. The proposed game model consists of two interrelated formulations: a stochastic game for dynamic defense and a best response policy using evolutionary game formulation for coordinator selection. The stable equilibrium best policy to response defense is obtained from this game model. It is shown that the proposed scheme can improve reliability and save energy during the network lifetime with respect to security.

A Probabilistic Approach to Mitigate Composition Attacks on Privacy in Non-Coordinated Environments

PubMed Central

Sarowar Sattar, A.H.M.; Li, Jiuyong; Liu, Jixue; Heatherly, Raymond; Malin, Bradley

2014-01-01

Organizations share data about individuals to drive business and comply with law and regulation. However, an adversary may expose confidential information by tracking an individual across disparate data publications using quasi-identifying attributes (e.g., age, geocode and sex) associated with the records. Various studies have shown that well-established privacy protection models (e.g., k-anonymity and its extensions) fail to protect an individual’s privacy against this “composition attack”. This type of attack can be thwarted when organizations coordinate prior to data publication, but such a practice is not always feasible. In this paper, we introduce a probabilistic model called (d, α)-linkable, which mitigates composition attack without coordination. The model ensures that d confidential values are associated with a quasi-identifying group with a likelihood of α. We realize this model through an efficient extension to k-anonymization and use extensive experiments to show our strategy significantly reduces the likelihood of a successful composition attack and can preserve more utility than alternative privacy models, such as differential privacy. PMID:25598581

A Cascade Optimization Strategy for Solution of Difficult Multidisciplinary Design Problems

NASA Technical Reports Server (NTRS)

Patnaik, Surya N.; Coroneos, Rula M.; Hopkins, Dale A.; Berke, Laszlo

1996-01-01

A research project to comparatively evaluate 10 nonlinear optimization algorithms was recently completed. A conclusion was that no single optimizer could successfully solve all 40 problems in the test bed, even though most optimizers successfully solved at least one-third of the problems. We realized that improved search directions and step lengths, available in the 10 optimizers compared, were not likely to alleviate the convergence difficulties. For the solution of those difficult problems we have devised an alternative approach called cascade optimization strategy. The cascade strategy uses several optimizers, one followed by another in a specified sequence, to solve a problem. A pseudorandom scheme perturbs design variables between the optimizers. The cascade strategy has been tested successfully in the design of supersonic and subsonic aircraft configurations and air-breathing engines for high-speed civil transport applications. These problems could not be successfully solved by an individual optimizer. The cascade optimization strategy, however, generated feasible optimum solutions for both aircraft and engine problems. This paper presents the cascade strategy and solutions to a number of these problems.

Optimized plasma actuation on asymmetric vortex over a slender body

NASA Astrophysics Data System (ADS)

Long, Yuexiao; Li, Huaxing; Meng, Xuanshi; Hu, Haiyang

2018-01-01

Detailed particle-image-velocimetry and surface pressure measurements are conducted to study asymmetric vortex control over a slender body at high angles of attack by using a pair of optimized alternating current surface-dielectric-barrier discharge plasma actuators. The Reynolds number based on the base diameter of the model is ReD = 3.8 × 105. Steady and duty-cycle manipulations are employed. The results demonstrate the effectiveness of the optimized actuator with a thick Teflon barrier at a high free-stream speed. Perfect linear proportional control is also achieved under duty-cycle control with a reduced frequency of f+ = 0.17.

Emergency strategy optimization for the environmental control system in manned spacecraft

NASA Astrophysics Data System (ADS)

Li, Guoxiang; Pang, Liping; Liu, Meng; Fang, Yufeng; Zhang, Helin

2018-02-01

It is very important for a manned environmental control system (ECS) to be able to reconfigure its operation strategy in emergency conditions. In this article, a multi-objective optimization is established to design the optimal emergency strategy for an ECS in an insufficient power supply condition. The maximum ECS lifetime and the minimum power consumption are chosen as the optimization objectives. Some adjustable key variables are chosen as the optimization variables, which finally represent the reconfigured emergency strategy. The non-dominated sorting genetic algorithm-II is adopted to solve this multi-objective optimization problem. Optimization processes are conducted at four different carbon dioxide partial pressure control levels. The study results show that the Pareto-optimal frontiers obtained from this multi-objective optimization can represent the relationship between the lifetime and the power consumption of the ECS. Hence, the preferred emergency operation strategy can be recommended for situations when there is suddenly insufficient power.

Network Robustness: the whole story

NASA Astrophysics Data System (ADS)

Longjas, A.; Tejedor, A.; Zaliapin, I. V.; Ambroj, S.; Foufoula-Georgiou, E.

2014-12-01

A multitude of actual processes operating on hydrological networks may exhibit binary outcomes such as clean streams in a river network that may become contaminated. These binary outcomes can be modeled by node removal processes (attacks) acting in a network. Network robustness against attacks has been widely studied in fields as diverse as the Internet, power grids and human societies. However, the current definition of robustness is only accounting for the connectivity of the nodes unaffected by the attack. Here, we put forward the idea that the connectivity of the affected nodes can play a crucial role in proper evaluation of the overall network robustness and its future recovery from the attack. Specifically, we propose a dual perspective approach wherein at any instant in the network evolution under attack, two distinct networks are defined: (i) the Active Network (AN) composed of the unaffected nodes and (ii) the Idle Network (IN) composed of the affected nodes. The proposed robustness metric considers both the efficiency of destroying the AN and the efficiency of building-up the IN. This approach is motivated by concrete applied problems, since, for example, if we study the dynamics of contamination in river systems, it is necessary to know both the connectivity of the healthy and contaminated parts of the river to assess its ecological functionality. We show that trade-offs between the efficiency of the Active and Idle network dynamics give rise to surprising crossovers and re-ranking of different attack strategies, pointing to significant implications for decision making.

Specialised use of working memory by Portia africana, a spider-eating salticid.

PubMed

Cross, Fiona R; Jackson, Robert R

2014-03-01

Using expectancy-violation methods, we investigated the role of working memory in the predatory strategy of Portia africana, a salticid spider from Kenya that preys by preference on other spiders. One of this predator's tactics is to launch opportunistic leaping attacks on to other spiders in their webs. Focussing on this particular tactic, our experiments began with a test spider on a ramp facing a lure (dead prey spider mounted on a cork disc) that could be reached by leaping. After the test spider faced the lure for 30 s, we blocked the test spider's view of the lure by lowering an opaque shutter before the spider leapt. When the shutter was raised 90 s later, either the same lure came into view again (control) or a different lure came into view (experimental: different prey type in same orientation or same prey type in different orientation). We recorded attack frequency (number of test spiders that leapt at the lure) and attack latency (time elapsing between shutter being raised and spiders initiating a leap). Attack latencies in control trials were not significantly different from attack latencies in experimental trials, regardless of whether it was prey type or prey orientation that changed in the experimental trials. However, compared with test spiders in the no-change control trials, significantly fewer test spiders leapt when prey type changed. There was no significant effect on attack frequency when prey orientation changed. These findings suggest that this predator represents prey type independently of prey orientation.

A study of the application of singular perturbation theory. [development of a real time algorithm for optimal three dimensional aircraft maneuvers

NASA Technical Reports Server (NTRS)

Mehra, R. K.; Washburn, R. B.; Sajan, S.; Carroll, J. V.

1979-01-01

A hierarchical real time algorithm for optimal three dimensional control of aircraft is described. Systematic methods are developed for real time computation of nonlinear feedback controls by means of singular perturbation theory. The results are applied to a six state, three control variable, point mass model of an F-4 aircraft. Nonlinear feedback laws are presented for computing the optimal control of throttle, bank angle, and angle of attack. Real Time capability is assessed on a TI 9900 microcomputer. The breakdown of the singular perturbation approximation near the terminal point is examined Continuation methods are examined to obtain exact optimal trajectories starting from the singular perturbation solutions.

Fast Fragmentation of Networks Using Module-Based Attacks

PubMed Central

Requião da Cunha, Bruno; González-Avella, Juan Carlos; Gonçalves, Sebastián

2015-01-01

In the multidisciplinary field of Network Science, optimization of procedures for efficiently breaking complex networks is attracting much attention from a practical point of view. In this contribution, we present a module-based method to efficiently fragment complex networks. The procedure firstly identifies topological communities through which the network can be represented using a well established heuristic algorithm of community finding. Then only the nodes that participate of inter-community links are removed in descending order of their betweenness centrality. We illustrate the method by applying it to a variety of examples in the social, infrastructure, and biological fields. It is shown that the module-based approach always outperforms targeted attacks to vertices based on node degree or betweenness centrality rankings, with gains in efficiency strongly related to the modularity of the network. Remarkably, in the US power grid case, by deleting 3% of the nodes, the proposed method breaks the original network in fragments which are twenty times smaller in size than the fragments left by betweenness-based attack. PMID:26569610

Nonlinear time-series-based adaptive control applications

NASA Technical Reports Server (NTRS)

Mohler, R. R.; Rajkumar, V.; Zakrzewski, R. R.

1991-01-01

A control design methodology based on a nonlinear time-series reference model is presented. It is indicated by highly nonlinear simulations that such designs successfully stabilize troublesome aircraft maneuvers undergoing large changes in angle of attack as well as large electric power transients due to line faults. In both applications, the nonlinear controller was significantly better than the corresponding linear adaptive controller. For the electric power network, a flexible AC transmission system with series capacitor power feedback control is studied. A bilinear autoregressive moving average reference model is identified from system data, and the feedback control is manipulated according to a desired reference state. The control is optimized according to a predictive one-step quadratic performance index. A similar algorithm is derived for control of rapid changes in aircraft angle of attack over a normally unstable flight regime. In the latter case, however, a generalization of a bilinear time-series model reference includes quadratic and cubic terms in angle of attack.

Cascading failures in interconnected networks with dynamical redistribution of loads

NASA Astrophysics Data System (ADS)

Zhao, Zhuang; Zhang, Peng; Yang, Hujiang

2015-09-01

Cascading failures of loads in isolated networks and coupled networks have been studied in the past few years. In most of the corresponding results, the topologies of the networks are destroyed. Here, we present an interconnected network model considering cascading failures based on the dynamic redistribution of flow in the networks. Compared with the results of single scale-free networks, we find that interconnected scale-free networks have higher vulnerability. Additionally, the network heterogeneity plays an important role in the robustness of interconnected networks under intentional attacks. Considering the effects of various coupling preferences, the results show that there are almost no differences. Finally, the application of our model to the Beijing interconnected traffic network, which consists of a subway network and a bus network, shows that the subway network suffers more damage under the attack. Moreover, the interconnected traffic network may be more exposed to damage after initial attacks on the bus network. These discussions are important for the design and optimization of interconnected networks.

A Study on Secure Medical-Contents Strategies with DRM Based on Cloud Computing

PubMed Central

Měsíček, Libor; Choi, Jongsun

2018-01-01

Many hospitals and medical clinics have been using a wearable sensor in its health care system because the wearable sensor, which is able to measure the patients' biometric information, has been developed to analyze their patients remotely. The measured information is saved to a server in a medical center, and the server keeps the medical information, which also involves personal information, on a cloud system. The server and network devices are used by connecting each other, and sensitive medical records are dealt with remotely. However, these days, the attackers, who try to attack the server or the network systems, are increasing. In addition, the server and the network system have a weak protection and security policy against the attackers. In this paper, it is suggested that security compliance of medical contents should be followed to improve the level of security. As a result, the medical contents are kept safely. PMID:29796233

Anthrax vaccines: present status and future prospects.

PubMed

Kaur, Manpreet; Singh, Samer; Bhatnagar, Rakesh

2013-08-01

The management of anthrax remains a top priority among the biowarfare/bioterror agents. It was the Bacillus anthracis spore attack through the US mail system after the September 11, 2001, terrorist attacks in the USA that highlighted the potential of B. anthracis as a bioterrorism agent and the threat posed by its deliberate dissemination. These attacks invigorated the efforts toward understanding the anthrax pathogenesis and development of more comprehensive medical intervention strategies for its containment in case of both natural disease and manmade, accidental or deliberate infection of a non-suspecting population. Currently, efforts are directed toward the development of safe and efficacious vaccines as well as intervention tools for controlling the disease in the advanced fulminant stage when toxemia has already developed. This work presents an overview of the current understanding of anthrax pathogenesis and recent advances made, particularly after 2001, for the successful management of anthrax and outlines future perspectives.

Measurement-device-independent quantum coin tossing

NASA Astrophysics Data System (ADS)

Zhao, Liangyuan; Yin, Zhenqiang; Wang, Shuang; Chen, Wei; Chen, Hua; Guo, Guangcan; Han, Zhengfu

2015-12-01

Quantum coin tossing (QCT) is an important primitive of quantum cryptography and has received continuous interest. However, in practical QCT, Bob's detectors can be subjected to detector-side channel attacks launched by dishonest Alice, which will possibly make the protocol completely insecure. Here, we report a simple strategy of a detector-blinding attack based on a recent experiment. To remove all the detector side channels, we present a solution of measurement-device-independent QCT (MDI-QCT). This method is similar to the idea of MDI quantum key distribution (QKD). MDI-QCT is loss tolerant with single-photon sources and has the same bias as the original loss-tolerant QCT under a coherent attack. Moreover, it provides the potential advantage of doubling the secure distance for some special cases. Finally, MDI-QCT can also be modified to fit the weak coherent-state sources. Thus, based on the rapid development of practical MDI-QKD, our proposal can be implemented easily.

A Study on Secure Medical-Contents Strategies with DRM Based on Cloud Computing.

PubMed

Ko, Hoon; Měsíček, Libor; Choi, Jongsun; Hwang, Seogchan

2018-01-01

Many hospitals and medical clinics have been using a wearable sensor in its health care system because the wearable sensor, which is able to measure the patients' biometric information, has been developed to analyze their patients remotely. The measured information is saved to a server in a medical center, and the server keeps the medical information, which also involves personal information, on a cloud system. The server and network devices are used by connecting each other, and sensitive medical records are dealt with remotely. However, these days, the attackers, who try to attack the server or the network systems, are increasing. In addition, the server and the network system have a weak protection and security policy against the attackers. In this paper, it is suggested that security compliance of medical contents should be followed to improve the level of security. As a result, the medical contents are kept safely.

Suicide to harass others: clues from mythology to understanding suicide bombing attacks.

PubMed

Preti, Antonio

2006-01-01

Suicide by revenge, the Samsonic suicide, and the suicide by devotio, all described in classical mythology and also reported in the ethnographic literature, belong to the same class of suicidal behaviors as kamikaze suicide and the suicide bombing attack: suicide to harass and burden others or suicide with a hostile intent. The lack of a social dimension to share in a positive manner may lead an individual to integrate him/herself in another social structure, e.g., a military organization, which allows the individual to express his/her desires and personal identity only by destroying others and themselves. The dynamics of these forms of suicide are also likely to work in other displays of life-threatening behavior, such as family annihilation, mass murder, and spree killing. A more thorough investigation of the dynamics operating in suicide bombing attacks could, therefore, contribute to preventative strategies against violence at large.

[Optimization of acupoint application scheme in the treatment of bronchial asthma based on the orthogonal design method].

PubMed

Shi, Kuan; Wu, Wenzhong; Liu, Lanying; Wang, Hesheng; Chen, Dong; Liu, Chengyong; Zhang, Cong

2017-06-12

To study the primary and secondary factors of the allergic history, the frequency of acupoint application and the time of acupoint application in the treatment of bronchial asthma and optimize its scheme. Eighty patients of bronchial asthma were selected as the subjects in the orthogonal trial. The herbal medicines were the empirical formula of acupoint application (prepared at the ratio as 2:2:1:1:1:1:1:1:1 of semen brassicae , rhizome corydalis , unprocessed radix kansui , asarum sieboldii , ephedra , semen lepidii , syzygium aromaticum , cortex cinnamomi and fructus gleditsiae ) and used on bilateral Feishu (BL 13), Xinshu (BL 15), Geshu (BL 17) and Shenshu (BL 23). Firstly, two groups were divided according to allergic history (40 cases with allergic history and 40 cases without allergic history), and then four subgroups were divided on the basis of the two main groups, 10 cases in each one. Through studying three factors and two levels, i.e. allergic history (Factor A:A Ⅰ :with allergic history; A Ⅱ :without allergic history), the frequency of acupoint application (Factor B:B Ⅰ :4 times; B Ⅱ :10 times, in which, in the group of 4-time applications, the application was given once every 10 days; in the group of 10-time applications, the application was given once every 4 days); and the time of application (Factor C:C Ⅰ :4 h; C Ⅱ :8 h), the optimal scheme was screened on the basis of the attack frequency before and after treatment and the score of the asthma quality life questionnaire (AQLQ) before treatment and 6 months after treatment in the patients of each group. ① The orthogonal trial indicated that the best optimal scheme was A Ⅰ B Ⅱ C Ⅰ , meaning the patients with allergic history were treated with acupoint application for 10 times, remained for 4 h. ②Factor B (frequency of acupoint application) and C (time of acpoint application) were the significant influential factors of AQLQ scores (both P <0.05). ③The comparison of the attack frequency and AQLQ score before and after treatment in all of the patients showed that the different combinations of factor levels induced the different impacts on the asthma attack frequency and AQLQ scores. Except in the group No.1 and the group No.5, the improvements were all significant in the rest groups, indicating the significant differences ( P <0.05, P <0.01). Acupoint application reduces apparently the attack frequency of asthma in the patients and improves the living quality. The primary and secondary relationship among the allergic history, the frequency of acupoint application and the time of acupoint application for the impacts on the therapeutic effects are:the frequency of acupoint application > the time of acupoint application > the allergic history. The best optimal scheme is A Ⅰ B Ⅱ C Ⅰ , meaning the patients with allergic history are treated with acupoint application for 10 times, remained for 4h.

A new way to improve the robustness of complex communication networks by allocating redundancy links

NASA Astrophysics Data System (ADS)

Shi, Chunhui; Peng, Yunfeng; Zhuo, Yue; Tang, Jieying; Long, Keping

2012-03-01

We investigate the robustness of complex communication networks on allocating redundancy links. The protecting key nodes (PKN) strategy is proposed to improve the robustness of complex communication networks against intentional attack. Our numerical simulations show that allocating a few redundant links among key nodes using the PKN strategy will significantly increase the robustness of scale-free complex networks. We have also theoretically proved and demonstrated the effectiveness of the PKN strategy. We expect that our work will help achieve a better understanding of communication networks.

Optimal resource allocation for defense of targets based on differing measures of attractiveness.

PubMed

Bier, Vicki M; Haphuriwat, Naraphorn; Menoyo, Jaime; Zimmerman, Rae; Culpen, Alison M

2008-06-01

This article describes the results of applying a rigorous computational model to the problem of the optimal defensive resource allocation among potential terrorist targets. In particular, our study explores how the optimal budget allocation depends on the cost effectiveness of security investments, the defender's valuations of the various targets, and the extent of the defender's uncertainty about the attacker's target valuations. We use expected property damage, expected fatalities, and two metrics of critical infrastructure (airports and bridges) as our measures of target attractiveness. Our results show that the cost effectiveness of security investment has a large impact on the optimal budget allocation. Also, different measures of target attractiveness yield different optimal budget allocations, emphasizing the importance of developing more realistic terrorist objective functions for use in budget allocation decisions for homeland security.

A real-time guidance algorithm for aerospace plane optimal ascent to low earth orbit

NASA Technical Reports Server (NTRS)

Calise, A. J.; Flandro, G. A.; Corban, J. E.

1989-01-01

Problems of onboard trajectory optimization and synthesis of suitable guidance laws for ascent to low Earth orbit of an air-breathing, single-stage-to-orbit vehicle are addressed. A multimode propulsion system is assumed which incorporates turbojet, ramjet, Scramjet, and rocket engines. An algorithm for generating fuel-optimal climb profiles is presented. This algorithm results from the application of the minimum principle to a low-order dynamic model that includes angle-of-attack effects and the normal component of thrust. Maximum dynamic pressure and maximum aerodynamic heating rate constraints are considered. Switching conditions are derived which, under appropriate assumptions, govern optimal transition from one propulsion mode to another. A nonlinear transformation technique is employed to derived a feedback controller for tracking the computed trajectory. Numerical results illustrate the nature of the resulting fuel-optimal climb paths.

Determining the scope of attacks on health in four governorates of Syria in 2016: Results of a field surveillance program

PubMed Central

Risko, Casey B.; Rayes, Diana; Albaik, Ahmad; Alnajar, Mohammed; Kewara, Mazen; Baker, Elise; Rubenstein, Leonard S.

2018-01-01

Background Violent attacks on and interferences with hospitals, ambulances, health workers, and patients during conflict destroy vital health services during a time when they are most needed and undermine the long-term capacity of the health system. In Syria, such attacks have been frequent and intense and represent grave violations of the Geneva Conventions, but the number reported has varied considerably. A systematic mechanism to document these attacks could assist in designing more protection strategies and play a critical role in influencing policy, promoting justice, and addressing the health needs of the population. Methods and findings We developed a mobile data collection questionnaire to collect data on incidents of attacks on healthcare directly from the field. Data collectors from the Syrian American Medical Society (SAMS), using the tool or a text messaging system, recorded information on incidents across four of Syria’s northern governorates (Aleppo, Idleb, Hama, and Homs) from January 1, 2016, to December 31, 2016. SAMS recorded a total of 200 attacks on healthcare in 2016, 102 of them using the mobile data collection tool. Direct attacks on health facilities comprised the majority of attacks recorded (88.0%; n = 176). One hundred and twelve healthcare staff and 185 patients were killed in these incidents. Thirty-five percent of the facilities were attacked more than once over the data collection period; hospitals were significantly more likely to be attacked more than once compared to clinics and other types of healthcare facilities. Aerial bombs were used in the overwhelming majority of cases (91.5%). We also compared the SAMS data to a separate database developed by Physicians for Human Rights (PHR) based on media reports and matched the incidents to compare the results from the two methods (this analysis was limited to incidents at health facilities). Among 90 relevant incidents verified by PHR and 177 by SAMS, there were 60 that could be matched to each other, highlighting the differences in results from the two methods. This study is limited by the complexities of data collection in a conflict setting, only partial use of the standardized reporting tool, and the fact that limited accessibility of some health facilities and workers and may be biased towards the reporting of attacks on larger or more visible health facilities. Conclusions The use of field data collectors and use of consistent definitions can play an important role in the tracking incidents of attacks on health services. A mobile systematic data collection tool can complement other methods for tracking incidents of attacks on healthcare and ensure the collection of detailed information about each attack that may assist in better advocacy, programs, and accountability but can be practically challenging. Comparing attacks between SAMS and PHR suggests that there may have been significantly more attacks than previously captured by any one methodology. This scale of attacks suggests that targeting of healthcare in Syria is systematic and highlights the failure of condemnation by the international community and medical groups working in Syria of such attacks to stop them. PMID:29689085

Kevlar: Transitioning Helix from Research to Practice

DTIC Science & Technology

2015-04-01

protective transformations are applied to application binaries before they are deployed. Salient features of Kevlar include applying high- entropy ...variety of classes. Kevlar uses novel, fine-grained, high- entropy diversification transformations to prevent an attacker from successfully exploiting...Kevlar include applying high- entropy randomization techniques, automated program repairs, leveraging highly-optimized virtual machine technology, and in

Kevlar: Transitioning Helix for Research to Practice

DTIC Science & Technology

2016-03-01

entropy randomization techniques, automated program repairs leveraging highly-optimized virtual machine technology, and developing a novel framework...attacker from exploiting residual vulnerabilities in a wide variety of classes. Helix/Kevlar uses novel, fine-grained, high- entropy diversification...the Air Force, and IARPA). Salient features of Helix/Kevlar include developing high- entropy randomization techniques, automated program repairs

Back to the Future: Integrated Air and Missile Defense in the Pacific

DTIC Science & Technology

2015-02-01

US assets with those of our allies and partners, we have optimized our defense design, pre- venting the waste of precious interceptors. The Pacific...Good Offense: Attack Operations Power projection is, and always will be, th e bread and butter of the US Air Force. Only the United States can

The role of aquaporins in pH-Dependent germination of Rhizopus delemar spores

USDA-ARS?s Scientific Manuscript database

Rhizopus delemar and associated species attack a wide range of fruit and vegetables after harvest. Host nutrients and acidic pH are required for optimal germination of R. delemar, and we studied how this process is triggered. Glucose induced spore swelling in an acidic environment, expressed by an u...

Effects of temperature on the life history parameters of Anoplophora Glabripennis (Coleoptera: Cerambycidae)

Treesearch

Melody A. Keena; Paul M. Moore; Steve M. Ulanecki

2003-01-01

There is a critical need for information on the basic biology of the Asian longhorned beetle, Anoplophora glabripennis (Motschulsky), to provide the biological basis for predicting developmental phenology in order to optimize the timing of exclusion and eradication treatments and to predict attack rates under different environmental conditions. In...

A Hypergraph and Arithmetic Residue-based Probabilistic Neural Network for classification in Intrusion Detection Systems.

PubMed

Raman, M R Gauthama; Somu, Nivethitha; Kirthivasan, Kannan; Sriram, V S Shankar

2017-08-01

Over the past few decades, the design of an intelligent Intrusion Detection System (IDS) remains an open challenge to the research community. Continuous efforts by the researchers have resulted in the development of several learning models based on Artificial Neural Network (ANN) to improve the performance of the IDSs. However, there exists a tradeoff with respect to the stability of ANN architecture and the detection rate for less frequent attacks. This paper presents a novel approach based on Helly property of Hypergraph and Arithmetic Residue-based Probabilistic Neural Network (HG AR-PNN) to address the classification problem in IDS. The Helly property of Hypergraph was exploited for the identification of the optimal feature subset and the arithmetic residue of the optimal feature subset was used to train the PNN. The performance of HG AR-PNN was evaluated using KDD CUP 1999 intrusion dataset. Experimental results prove the dominance of HG AR-PNN classifier over the existing classifiers with respect to the stability and improved detection rate for less frequent attacks. Copyright © 2017 Elsevier Ltd. All rights reserved.

The adaptive function of tiger moth clicks against echolocating bats: an experimental and synthetic approach.

PubMed

Ratcliffe, John M; Fullard, James H

2005-12-01

We studied the efficiency and effects of the multiple sensory cues of tiger moths on echolocating bats. We used the northern long-eared bat, Myotis septentrionalis, a purported moth specialist that takes surface-bound prey (gleaning) and airborne prey (aerial hawking), and the dogbane tiger moth, Cycnia tenera, an eared species unpalatable to bats that possesses conspicuous colouration and sound-producing organs (tymbals). This is the first study to investigate the interaction of tiger moths and wild-caught bats under conditions mimicking those found in nature and to demand the use of both aerial hawking and gleaning strategies by bats. Further, it is the first to report spectrograms of the sounds produced by tiger moths while under aerial attack by echolocating bats. During both aerial hawking and gleaning trials, all muted C. tenera and perched intact C. tenera were attacked by M. septentrionalis, indicating that M. septentrionalis did not discriminate C. tenera from palatable moths based on potential echoic and/or non-auditory cues. Intact C. tenera were attacked significantly less often than muted C. tenera during aerial hawking attacks: tymbal clicks were therefore an effective deterrent in an aerial hawking context. During gleaning attacks, intact and muted C. tenera were always attacked and suffered similar mortality rates, suggesting that while handling prey this bat uses primarily chemical signals. Our results also show that C. tenera temporally matches the onset of click production to the ;approach phase' echolocation calls produced by aerial hawking attacking bats and that clicks themselves influence the echolocation behaviour of attacking bats. In the context of past research, these findings support the hypotheses that the clicks of arctiid moths are both an active defence (through echolocation disruption) and a reliable indicator of chemical defence against aerial-hawking bats. We suggest these signals are specialized for an aerial context.

Cholera in Cameroon, 2000-2012: Spatial and Temporal Analysis at the Operational (Health District) and Sub Climate Levels.

PubMed

Ngwa, Moise C; Liang, Song; Kracalik, Ian T; Morris, Lillian; Blackburn, Jason K; Mbam, Leonard M; Ba Pouth, Simon Franky Baonga; Teboh, Andrew; Yang, Yang; Arabi, Mouhaman; Sugimoto, Jonathan D; Morris, John Glenn

2016-11-01

Recurrent cholera outbreaks have been reported in Cameroon since 1971. However, case fatality ratios remain high, and we do not have an optimal understanding of the epidemiology of the disease, due in part to the diversity of Cameroon's climate subzones and a lack of comprehensive data at the health district level. A unique health district level dataset of reported cholera case numbers and related deaths from 2000-2012, obtained from the Ministry of Public Health of Cameroon and World Health Organization (WHO) country office, served as the basis for the analysis. During this time period, 43,474 cholera cases were reported: 1748 were fatal (mean annual case fatality ratio of 7.9%), with an attack rate of 17.9 reported cases per 100,000 inhabitants per year. Outbreaks occurred in three waves during the 13-year time period, with the highest case fatality ratios at the beginning of each wave. Seasonal patterns of illness differed strikingly between climate subzones (Sudano-Sahelian, Tropical Humid, Guinea Equatorial, and Equatorial Monsoon). In the northern Sudano-Sahelian subzone, highest number of cases tended to occur during the rainy season (July-September). The southern Equatorial Monsoon subzone reported cases year-round, with the lowest numbers during peak rainfall (July-September). A spatial clustering analysis identified multiple clusters of high incidence health districts during 2010 and 2011, which were the 2 years with the highest annual attack rates. A spatiotemporal autoregressive Poisson regression model fit to the 2010-2011 data identified significant associations between the risk of transmission and several factors, including the presence of major waterbody or highway, as well as the average daily maximum temperature and the precipitation levels over the preceding two weeks. The direction and/or magnitude of these associations differed between climate subzones, which, in turn, differed from national estimates that ignored subzones differences in climate variables. The epidemiology of cholera in Cameroon differs substantially between climate subzones. Development of an optimal comprehensive country-wide control strategy for cholera requires an understanding of the impact of the natural and built environment on transmission patterns at the local level, particularly in the setting of ongoing climate change.

Optimal Design of Passive Flow Control for a Boundary-Layer-Ingesting Offset Inlet Using Design-of-Experiments

NASA Technical Reports Server (NTRS)

Allan, Brian G.; Owens, Lewis R.; Lin, John C.

2006-01-01

This research will investigate the use of Design-of-Experiments (DOE) in the development of an optimal passive flow control vane design for a boundary-layer-ingesting (BLI) offset inlet in transonic flow. This inlet flow control is designed to minimize the engine fan-face distortion levels and first five Fourier harmonic half amplitudes while maximizing the inlet pressure recovery. Numerical simulations of the BLI inlet are computed using the Reynolds-averaged Navier-Stokes (RANS) flow solver, OVERFLOW, developed at NASA. These simulations are used to generate the numerical experiments for the DOE response surface model. In this investigation, two DOE optimizations were performed using a D-Optimal Response Surface model. The first DOE optimization was performed using four design factors which were vane height and angles-of-attack for two groups of vanes. One group of vanes was placed at the bottom of the inlet and a second group symmetrically on the sides. The DOE design was performed for a BLI inlet with a free-stream Mach number of 0.85 and a Reynolds number of 2 million, based on the length of the fan-face diameter, matching an experimental wind tunnel BLI inlet test. The first DOE optimization required a fifth order model having 173 numerical simulation experiments and was able to reduce the DC60 baseline distortion from 64% down to 4.4%, while holding the pressure recovery constant. A second DOE optimization was performed holding the vanes heights at a constant value from the first DOE optimization with the two vane angles-of-attack as design factors. This DOE only required a second order model fit with 15 numerical simulation experiments and reduced DC60 to 3.5% with small decreases in the fourth and fifth harmonic amplitudes. The second optimal vane design was tested at the NASA Langley 0.3- Meter Transonic Cryogenic Tunnel in a BLI inlet experiment. The experimental results showed a 80% reduction of DPCP(sub avg), the circumferential distortion level at the engine fan-face.

Optimal Design of Passive Flow Control for a Boundary-Layer-Ingesting Offset Inlet Using Design-of-Experiments

NASA Technical Reports Server (NTRS)

Allan, Brian G.; Owens, Lewis R., Jr.; Lin, John C.

2006-01-01

This research will investigate the use of Design-of-Experiments (DOE) in the development of an optimal passive flow control vane design for a boundary-layer-ingesting (BLI) offset inlet in transonic flow. This inlet flow control is designed to minimize the engine fan face distortion levels and first five Fourier harmonic half amplitudes while maximizing the inlet pressure recovery. Numerical simulations of the BLI inlet are computed using the Reynolds-averaged Navier-Stokes (RANS) flow solver, OVERFLOW, developed at NASA. These simulations are used to generate the numerical experiments for the DOE response surface model. In this investigation, two DOE optimizations were performed using a D-Optimal Response Surface model. The first DOE optimization was performed using four design factors which were vane height and angles-of-attack for two groups of vanes. One group of vanes was placed at the bottom of the inlet and a second group symmetrically on the sides. The DOE design was performed for a BLI inlet with a free-stream Mach number of 0.85 and a Reynolds number of 2 million, based on the length of the fan face diameter, matching an experimental wind tunnel BLI inlet test. The first DOE optimization required a fifth order model having 173 numerical simulation experiments and was able to reduce the DC60 baseline distortion from 64% down to 4.4%, while holding the pressure recovery constant. A second DOE optimization was performed holding the vanes heights at a constant value from the first DOE optimization with the two vane angles-of-attack as design factors. This DOE only required a second order model fit with 15 numerical simulation experiments and reduced DC60 to 3.5% with small decreases in the fourth and fifth harmonic amplitudes. The second optimal vane design was tested at the NASA Langley 0.3-Meter Transonic Cryogenic Tunnel in a BLI inlet experiment. The experimental results showed a 80% reduction of DPCPavg, the circumferential distortion level at the engine fan face.

Assessing Maritime Aspects of the AirSea Battle Concept

DTIC Science & Technology

2012-03-23

AirSea Battle centered on the assessment that in hostilities the PRC would conduct a rapid preemptive attack to knock back U.S. and allied forces in...these factors provide the foundational need for a clear maritime strategy backed by strong naval power. ! The core of PRC maritime security strategy...Law Enforcement Command. This direct and indirect approach hearkens back to the theories of Sunzi and Mao Tse-tung. ! China’s 2010 National Defense

An Efficient Missile Loadout Planning Tool for Operational Planners

DTIC Science & Technology

2017-06-01

defense. Two cases were explored : one in which combat air patrol (CAP) was able to assist against the attack, and one without such assets. Dugan (2007...the Navy Operational Planner (NOP) to help decision makers with maritime operational planning. His work explores our Navy’s capability to accomplish...the elitist strategy of genetic algorithms. This strategy forms each new generation as a mix of the elite, or best, solutions carried over from

On Cyber Warfare Command and Control Systems

DTIC Science & Technology

2004-06-01

longer adequate to rely solely on the now traditional defense-in-depth strategy. We must recognize that we are engaged in a form of warfare, cyber warfare , and... warfare . This causes security devices to be used ineffectively and responses to be untimely. Cyber warfare then becomes a one-sided battle where the... cyber warfare strategy and tactics requires a cyber warfare command and control system. Responses to cyber attacks do not require offensive measures

U.S. Counterterrorism Landscape: An Examination of Policy and Strategy Using a Conceptual Approach

DTIC Science & Technology

2015-06-12

deterrence, destroy) may yield a different agency lead to implement CT strategy depending on the terrorist organization. The current struggle against...marshal and present evidence in overseas attack, while the FBI and the Justice Department would pursue traditional law enforcement methods to conduct...also fighting for the future of CIA/DOD integrated counterterrorism warfare around the globe. While we will make mistakes as we chart new territory

Writing Away from Fear: Mina Shaughnessy and the Uses of Authority.

ERIC Educational Resources Information Center

Allen, Michael

1980-01-01

Responds to John Rouse's attack on Mina Shaughnessy's teaching strategies for composition instruction (see EJ 209 264). Offers personal experiences to illustrate the role of the basic writing teacher and the uses of authority in the basic writing classroom. (JT)

A STRATEGY FOR INTEGRATED ECOLOGICAL RESTORATION OF RIPARIAN BUFFERS IN THE MID-ATLANTIC REGION

EPA Science Inventory

Increased sediments, nutrients, and other contaminants in the Mid-Atlantic region contribute to environmental problems ranging from stream degradation to possibly Pfiesteria attacks in Chesapeake Bay. Restoring riparian areas - the filters between terrestrial watersheds and aquat...

Plant Lectins: Wheat Defense Strategy Against Hessian Fly

USDA-ARS?s Scientific Manuscript database

Plants produce a variety of defense proteins, including lectins in response to attack by phytophagous insects. Ultrastructural studies reveal that binding to insect gut structures and resistance to proteolytic degradation by insect digestive enzymes are the two main prerequisites for the lectins to...

Theoretical studies of the transition state structures and free energy barriers for base-catalyzed hydrolysis of amides

PubMed Central

Xiong, Ying; Zhan, Chang-Guo

2010-01-01

The transition state structures and free energy barriers for the rate-determining step (i.e. the formation of a tetrahedral intermediate) of base-catalyzed hydrolysis of a series of amides in aqueous solution have been studied by performing first-principle electronic structure calculations using a hybrid supermolecule-polarizable continuum approach. The calculated results and a revisit of recently reported experimental proton inventory data reveal that the favorable transition state structure optimized for the tetrahedral intermediate formation of hydroxide ion-catalyzed hydrolysis of formamide may have three solvating water molecules remaining on the attacking hydroxide oxygen and two additional water molecules attached to the carbonyl oxygen of formamide. The calculated results have also demonstrated interesting substituent effects on the optimized transition state geometries, on the transition-state stabilization, and on the calculated free energy barriers for the base-catalyzed hydrolysis of amides. When some or all of the hydrogen atoms of formamide are replaced by methyl groups, the total number of water molecules hydrogen-bonding with the attacking hydroxide in the transition state decreases from three for formamide to two for N-methylacetamide, N,N-dimethylformamide (DMF), and N,N-dimethylacetamide (DMA). The larger substituents of the amide hinder the solvent water molecules approaching the attacking hydroxide oxygen in the transition state and, therefore, destabilize the transition state structure and increase the free energy barrier. By using the optimized most favorable transition state structures, the calculated free energy barriers, i.e. 21.6 (or 21.7), 22.7, 23.1, and 26.0 kcal/mol for formamide, N-methylacetamide, DMF, and DMA, respectively, are in good agreement with the available experimental free energy barriers, i.e. 21.2, 21.5, 22.6, and 24.1 kcal/mol for formamide, N-methylacetamide, DMF, and DMA, respectively. PMID:17107116

Density functional calculations on the effect of sulfur substitution for 2'-hydroxypropyl-p-nitrophenyl phosphate: C-O vs. P-O bond cleavage.

PubMed

Xia, Futing; Zhu, Hua

2012-02-01

Density functional theory calculations have been used to investigate the intra-molecular attack of 2'-hydroxypropyl-p-nitrophenyl phosphate (HPpNP) and its analogous compound 2-thiouridyl-p-nitrophenyl phosphate (s-2'pNP). Bulk solvent effect has been tested at the geometry optimization level with the polarized continuum model. It is found that the P-path involving the intra-molecular attack at the phosphorus atom and C-path involving the attack at the beta carbon atom proceed through the S(N)2-type mechanism for HPpNP and s-2'pNP. The calculated results indicate that the P-path with the free energy barrier of about 11 kcal/mol is more accessible than the C-path for the intra-molecular attack of HPpNP, which favors the formation of the five-membered phosphate diester. While for s-2'pNP, the C-path with the free energy barrier of about 21 kcal/mol proceeds more favorably than the P-path. The calculated energy barriers of the favorable pathways for HPpNP and s-2'pNP are both in agreement with the experimental results. Crown Copyright © 2011. Published by Elsevier Inc. All rights reserved.

Security of Continuous-Variable Quantum Key Distribution via a Gaussian de Finetti Reduction

NASA Astrophysics Data System (ADS)

Leverrier, Anthony

2017-05-01

Establishing the security of continuous-variable quantum key distribution against general attacks in a realistic finite-size regime is an outstanding open problem in the field of theoretical quantum cryptography if we restrict our attention to protocols that rely on the exchange of coherent states. Indeed, techniques based on the uncertainty principle are not known to work for such protocols, and the usual tools based on de Finetti reductions only provide security for unrealistically large block lengths. We address this problem here by considering a new type of Gaussian de Finetti reduction, that exploits the invariance of some continuous-variable protocols under the action of the unitary group U (n ) (instead of the symmetric group Sn as in usual de Finetti theorems), and by introducing generalized S U (2 ,2 ) coherent states. Crucially, combined with an energy test, this allows us to truncate the Hilbert space globally instead as at the single-mode level as in previous approaches that failed to provide security in realistic conditions. Our reduction shows that it is sufficient to prove the security of these protocols against Gaussian collective attacks in order to obtain security against general attacks, thereby confirming rigorously the widely held belief that Gaussian attacks are indeed optimal against such protocols.

Security of Continuous-Variable Quantum Key Distribution via a Gaussian de Finetti Reduction.

PubMed

Leverrier, Anthony

2017-05-19

Establishing the security of continuous-variable quantum key distribution against general attacks in a realistic finite-size regime is an outstanding open problem in the field of theoretical quantum cryptography if we restrict our attention to protocols that rely on the exchange of coherent states. Indeed, techniques based on the uncertainty principle are not known to work for such protocols, and the usual tools based on de Finetti reductions only provide security for unrealistically large block lengths. We address this problem here by considering a new type of Gaussian de Finetti reduction, that exploits the invariance of some continuous-variable protocols under the action of the unitary group U(n) (instead of the symmetric group S_{n} as in usual de Finetti theorems), and by introducing generalized SU(2,2) coherent states. Crucially, combined with an energy test, this allows us to truncate the Hilbert space globally instead as at the single-mode level as in previous approaches that failed to provide security in realistic conditions. Our reduction shows that it is sufficient to prove the security of these protocols against Gaussian collective attacks in order to obtain security against general attacks, thereby confirming rigorously the widely held belief that Gaussian attacks are indeed optimal against such protocols.

Malaria attacks due to P. vivax or P. ovale in two French military teaching hospitals (2000 to 2009).

PubMed

Demaison, X; Rapp, C; de Laval, F; Simon, F

2013-04-01

Non-falciparum malaria is less studied than Plasmodium falciparum malaria, both in endemic and non-endemic zones. A retrospective study was made of the medical files of patients managed for attacks of malaria due to Plasmodium vivax or Plasmodium ovale, between 2000 and 2009, in two French military teaching hospitals. Seventy-five percent of attacks occurred after a stay in French Guiana, in the Comoros Archipelago, or in the Ivory Coast Republic. The most frequent symptoms two months after coming back were a flu-like syndrome with headaches, and occasional digestive symptoms, without any difference between the first attack and recurrence. One third of patients presented with anemia, 78% with thrombocytopenia, and 12% with liver dysfunction. This study was the most important made in France on imported non-falciparum malaria. Military patients and immigrants accounted for a majority of patients due to the specificity of military hospitals and local recruitment. Clinical and biological features were not specific and did not allow guiding the diagnosis. Diagnostic tools were less sensitive for P. ovale. Patient management could be optimized by more efficient diagnostic tools, specific guidelines for the diagnostic and therapeutic management, and a dedicated medical training for family practitioners as well as hospitals practice. Copyright © 2013. Published by Elsevier SAS.

Coping styles as moderating the relationships between terrorist attacks and well-being outcomes.

PubMed

Braun-Lewensohn, Orna; Celestin-Westreich, Smadar; Celestin, Leon-Patrice; Verleye, Gino; Verté, Dominique; Ponjaert-Kristoffersen, Ingrid

2009-06-01

This study aims to explore use of coping strategies among adolescents and their relationships with well being in the context of ongoing terrorism. Furthermore, we aim to explore to what extent coping styles in addition to exposure variables explain well being of adolescents facing ongoing terror. During September 2003, after three years of ongoing terror attacks, 913 Israeli adolescents aged 12-18 years, completed the following questionnaires during regular class sessions: Demographics, Achenbach's Youth Self Report; Exposure to Terror and Post Traumatic Stress (PTS) questionnaire; Adolescent Coping Scale (ACS) and Brief Symptoms Inventory. Adolescents employed mainly problem solving strategies which mean they have the capacity to cope well in spite of stressful events. Emotional focused coping was associated with PTS and mental health problems. Regression analysis of different exposure and coping variables revealed that exposure, appraisal (subjective exposure) and coping styles explained 26-37% of the variance of different psychological problems. The findings highlight the importance of appraisal (subjective exposure) and coping strategies, for understanding adolescents' mental health outcomes. Moreover, these findings are relevant to the development of prevention/intervention programs that facilitate youth's cognitive and emotional adjustments to ongoing trauma risks and terror threats.

Robustness of weighted networks

NASA Astrophysics Data System (ADS)

Bellingeri, Michele; Cassi, Davide

2018-01-01

Complex network response to node loss is a central question in different fields of network science because node failure can cause the fragmentation of the network, thus compromising the system functioning. Previous studies considered binary networks where the intensity (weight) of the links is not accounted for, i.e. a link is either present or absent. However, in real-world networks the weights of connections, and thus their importance for network functioning, can be widely different. Here, we analyzed the response of real-world and model networks to node loss accounting for link intensity and the weighted structure of the network. We used both classic binary node properties and network functioning measure, introduced a weighted rank for node importance (node strength), and used a measure for network functioning that accounts for the weight of the links (weighted efficiency). We find that: (i) the efficiency of the attack strategies changed using binary or weighted network functioning measures, both for real-world or model networks; (ii) in some cases, removing nodes according to weighted rank produced the highest damage when functioning was measured by the weighted efficiency; (iii) adopting weighted measure for the network damage changed the efficacy of the attack strategy with respect the binary analyses. Our results show that if the weighted structure of complex networks is not taken into account, this may produce misleading models to forecast the system response to node failure, i.e. consider binary links may not unveil the real damage induced in the system. Last, once weighted measures are introduced, in order to discover the best attack strategy, it is important to analyze the network response to node loss using nodes rank accounting the intensity of the links to the node.

Multi-constituent cardiovascular pills (MCCP)--challenges and promises of population-based prophylactic drug therapy for prevention of heart attack.

PubMed

Jamieson, Michael J; Naghavi, Morteza

2007-01-01

Risk factors for atherosclerotic cardiovascular disease (CVD) are highly co-prevalent but poorly identified and treated. The Screening for Heart Attack Prevention and Education (SHAPE) Task Force from the Association for Eradication of Heart Attack (AEHA) has recently proposed a new strategy that recommends screening for subclinical atherosclerosis and implementing aggressive treatment of "vulnerable patients". The Task Force has also envisioned future developments that may shift mass screening strategies to mass prophylactic therapy. The "Polypill" concept, introduced by Wald and Law suggests a combination of statin, low-dose antihypertensives, aspirin and folic acid, in a single pill, taken prophylactically by high risk population can cut CVD event rates by as much as 80%. In this communication, we review the challenges and promises of such a strategy. "Polypill" is but one of an astronomical number of possible multiconstituent pills (MCCP). Attractive as the MCCP concept is, it lacks evidence from randomized controlled trials, and begs numerous questions about the credibility of the concept, the design and synthesis of such complex pills, pharmacokinetics, pharmacodynamics, bioequivalence, "class" vs. unique properties, interactions, evidence of clinical efficacy and safety, regulatory approval, post-marketing surveillance, prescription vs. over-the-counter use, responsibility for initiating and monitoring therapy, patient education, counterfeiting and importation, reimbursement, advertisement, patent protection, commercial viability, etc. If these issues are favorably addressed, MCCP stand to dramatically change the manner in which CVD is prevented particularly in developing societies. Notwithstanding, assuming low commercial interests, realizing the promises of MCCP will demand serious attention from national public health policymakers. The clinical and regulatory implications of population-based secondary prevention (which rely on a different evidence base, and in which entirely different risk-benefit and cost-effectiveness considerations apply) remain issues for active debate.

Data security issues arising from integration of wireless access into healthcare networks.

PubMed

Frenzel, John C

2003-04-01

The versatility of having Ethernet speed connectivity without wires is rapidly driving adoption of wireless data networking by end users across all types of industry. Designed to be easy to configure and work among diverse platforms, wireless brings online data to mobile users. This functionality is particularly useful in modern clinical medicine. Wireless presents operators of networks containing or transmitting sensitive and confidential data with several new types of security vulnerabilities, and potentially opens previously protected core network resources to outside attack. Herein, we review the types of vulnerabilities, the tools necessary to exploit them, and strategies to thwart a successful attack.

Simple Backdoors on RSA Modulus by Using RSA Vulnerability

NASA Astrophysics Data System (ADS)

Sun, Hung-Min; Wu, Mu-En; Yang, Cheng-Ta

This investigation proposes two methods for embedding backdoors in the RSA modulus N=pq rather than in the public exponent e. This strategy not only permits manufacturers to embed backdoors in an RSA system, but also allows users to choose any desired public exponent, such as e=216+1, to ensure efficient encryption. This work utilizes lattice attack and exhaustive attack to embed backdoors in two proposed methods, called RSASBLT and RSASBES, respectively. Both approaches involve straightforward steps, making their running time roughly the same as that of normal RSA key-generation time, implying that no one can detect the backdoor by observing time imparity.

Security of a sessional blind signature based on quantum cryptograph

NASA Astrophysics Data System (ADS)

Wang, Tian-Yin; Cai, Xiao-Qiu; Zhang, Rui-Ling

2014-08-01

We analyze the security of a sessional blind signature protocol based on quantum cryptograph and show that there are two security leaks in this protocol. One is that the legal user Alice can change the signed message after she gets a valid blind signature from the signatory Bob, and the other is that an external opponent Eve also can forge a valid blind message by a special attack, which are not permitted for blind signature. Therefore, this protocol is not secure in the sense that it does not satisfy the non-forgeability of blind signatures. We also discuss the methods to prevent the attack strategies in the end.

Strategies of Echinococcus species responses to immune attacks: implications for therapeutic tool development.

PubMed

Zheng, Yadong

2013-11-01

Echinococcus species have been studied as a model to investigate parasite-host interactions. Echinococcus spp. can actively communicate dynamically with a host to facilitate infection, growth and proliferation partially via secretion of molecules, especially in terms of harmonization of host immune attacks. This review systematically outlines our current knowledge of how the Echinococcus species have evolved to adapt to their host's microenvironment. This understanding of parasite-host interplay has implications in profound appreciation of parasite plasticity and is informative in designing novel and effective tools including vaccines and drugs for the treatment of echinococcosis and other diseases. © 2013.

Transgenic sugarcane overexpressing CaneCPI-1 negatively affects the growth and development of the sugarcane weevil Sphenophorus levis.

PubMed

Schneider, Vanessa Karine; Soares-Costa, Andrea; Chakravarthi, Mohan; Ribeiro, Carolina; Chabregas, Sabrina Moutinho; Falco, Maria Cristina; Henrique-Silva, Flavio

2017-01-01

Transgenic sugarcane expressing CaneCPI-1 exhibits resistance to Sphenophorus levis larvae. Transgenic plants have widely been used to improve resistance against insect attack. Sugarcane is an economically important crop; however, great losses are caused by insect attack. Sphenophorus levis is a sugarcane weevil that digs tunnels in the stem base, leading to the destruction of the crop. This insect is controlled inefficiently by chemical insecticides. Transgenic plants expressing peptidase inhibitors represent an important strategy for impairing insect growth and development. Knowledge of the major peptidase group present in the insect gut is critical when choosing the most effective inhibitor. S. levis larvae use cysteine peptidases as their major digestive enzymes, primarily cathepsin L-like activity. In this study, we developed transgenic sugarcane plants that overexpress sugarcane cysteine peptidase inhibitor 1 (CaneCPI-1) and assessed their potential through feeding bioassays with S. levis larvae. Cystatin overexpression in the transgenic plants was evaluated using semi-quantitative RT-PCR, RT-qPCR, and immunoblot assays. A 50% reduction of the average weight was observed in larvae that fed on transgenic plants in comparison to larvae that fed on non-transgenic plants. In addition, transgenic sugarcane exhibited less damage caused by larval attack than the controls. Our results suggest that the overexpression of CaneCPI-1 in sugarcane is a promising strategy for improving resistance against this insect.

Secure estimation, control and optimization of uncertain cyber-physical systems with applications to power networks

NASA Astrophysics Data System (ADS)

Taha, Ahmad Fayez

Transportation networks, wearable devices, energy systems, and the book you are reading now are all ubiquitous cyber-physical systems (CPS). These inherently uncertain systems combine physical phenomena with communication, data processing, control and optimization. Many CPSs are controlled and monitored by real-time control systems that use communication networks to transmit and receive data from systems modeled by physical processes. Existing studies have addressed a breadth of challenges related to the design of CPSs. However, there is a lack of studies on uncertain CPSs subject to dynamic unknown inputs and cyber-attacks---an artifact of the insertion of communication networks and the growing complexity of CPSs. The objective of this dissertation is to create secure, computational foundations for uncertain CPSs by establishing a framework to control, estimate and optimize the operation of these systems. With major emphasis on power networks, the dissertation deals with the design of secure computational methods for uncertain CPSs, focusing on three crucial issues---(1) cyber-security and risk-mitigation, (2) network-induced time-delays and perturbations and (3) the encompassed extreme time-scales. The dissertation consists of four parts. In the first part, we investigate dynamic state estimation (DSE) methods and rigorously examine the strengths and weaknesses of the proposed routines under dynamic attack-vectors and unknown inputs. In the second part, and utilizing high-frequency measurements in smart grids and the developed DSE methods in the first part, we present a risk mitigation strategy that minimizes the encountered threat levels, while ensuring the continual observability of the system through available, safe measurements. The developed methods in the first two parts rely on the assumption that the uncertain CPS is not experiencing time-delays, an assumption that might fail under certain conditions. To overcome this challenge, networked unknown input observers---observers/estimators for uncertain CPSs---are designed such that the effect of time-delays and cyber-induced perturbations are minimized, enabling secure DSE and risk mitigation in the first two parts. The final part deals with the extreme time-scales encompassed in CPSs, generally, and smart grids, specifically. Operational decisions for long time-scales can adversely affect the security of CPSs for faster time-scales. We present a model that jointly describes steady-state operation and transient stability by combining convex optimal power flow with semidefinite programming formulations of an optimal control problem. This approach can be jointly utilized with the aforementioned parts of the dissertation work, considering time-delays and DSE. The research contributions of this dissertation furnish CPS stakeholders with insights on the design and operation of uncertain CPSs, whilst guaranteeing the system's real-time safety. Finally, although many of the results of this dissertation are tailored to power systems, the results are general enough to be applied for a variety of uncertain CPSs.

Ocular Involvement of Behçet's Syndrome: a Comprehensive Review.

PubMed

Ozyazgan, Yilmaz; Ucar, Didar; Hatemi, Gulen; Yazici, Yusuf

2015-12-01

Behçet's syndrome (BS) is a vasculitis involving several organ systems including the eyes. Ocular involvement is one of the most disabling complications of BS, causing loss of vision that may progress to blindness if left untreated. The typical form of ocular involvement is a relapsing and remitting panuveitis and retinal vasculitis. Initial attacks may spontaneously improve and subsequently disappear in a few weeks but tend to recur if left untreated. Destructive and recurrent attacks, especially with posterior segment and retina involvement, may cause irreversible ocular structural changes and permanent damage in sensory retina, resulting in loss of vision. The risk of irreversible damage to ocular tissue which may result in loss of vision warrants early and intensive treatment especially in patients at high risk such as young men who tend to follow an aggressive disease course. The management strategy involves rapid suppression of inflammation during the attacks and prevention of recurrent attacks. Local and systemic measures including immunosuppressives, corticosteroids, and biologic agents are used for this purpose. Surgery may be required in selected cases. The prognosis of eye involvement has greatly improved over the last decades with the effective use of immunosuppressives.

Moth tails divert bat attack: evolution of acoustic deflection.

PubMed

Barber, Jesse R; Leavell, Brian C; Keener, Adam L; Breinholt, Jesse W; Chadwell, Brad A; McClure, Christopher J W; Hill, Geena M; Kawahara, Akito Y

2015-03-03

Adaptations to divert the attacks of visually guided predators have evolved repeatedly in animals. Using high-speed infrared videography, we show that luna moths (Actias luna) generate an acoustic diversion with spinning hindwing tails to deflect echolocating bat attacks away from their body and toward these nonessential appendages. We pit luna moths against big brown bats (Eptesicus fuscus) and demonstrate a survival advantage of ∼ 47% for moths with tails versus those that had their tails removed. The benefit of hindwing tails is equivalent to the advantage conferred to moths by bat-detecting ears. Moth tails lured bat attacks to these wing regions during 55% of interactions between bats and intact luna moths. We analyzed flight kinematics of moths with and without hindwing tails and suggest that tails have a minimal role in flight performance. Using a robust phylogeny, we find that long spatulate tails have independently evolved four times in saturniid moths, further supporting the selective advantage of this anti-bat strategy. Diversionary tactics are perhaps more common than appreciated in predator-prey interactions. Our finding suggests that focusing on the sensory ecologies of key predators will reveal such countermeasures in prey.

General immunity and superadditivity of two-way Gaussian quantum cryptography.

PubMed

Ottaviani, Carlo; Pirandola, Stefano

2016-03-01

We consider two-way continuous-variable quantum key distribution, studying its security against general eavesdropping strategies. Assuming the asymptotic limit of many signals exchanged, we prove that two-way Gaussian protocols are immune to coherent attacks. More precisely we show the general superadditivity of the two-way security thresholds, which are proven to be higher than the corresponding one-way counterparts in all cases. We perform the security analysis first reducing the general eavesdropping to a two-mode coherent Gaussian attack, and then showing that the superadditivity is achieved by exploiting the random on/off switching of the two-way quantum communication. This allows the parties to choose the appropriate communication instances to prepare the key, accordingly to the tomography of the quantum channel. The random opening and closing of the circuit represents, in fact, an additional degree of freedom allowing the parties to convert, a posteriori, the two-mode correlations of the eavesdropping into noise. The eavesdropper is assumed to have no access to the on/off switching and, indeed, cannot adapt her attack. We explicitly prove that this mechanism enhances the security performance, no matter if the eavesdropper performs collective or coherent attacks.

Force production and time-averaged flow structure around thin, non-slender delta wings

NASA Astrophysics Data System (ADS)

Tu, Han; Green, Melissa

2017-11-01

Experimental force measurement and time-averaged three dimensional flow visualization of low Reynolds number baseline cases have been carried out on a steady flat plate delta wing. Current data will serve as steady reference for future unsteady flow and actuation cases. The comprehensive study will compare force production in highly unsteady environments, which is necessary to consider in unmanned combat aerial vehicle (UCAV) control strategies. Force measurements are carried out at angles of attack 10, 15, 20, 25 and 30 degrees. The coefficient of drag increases with angle of attack, while the coefficient of lift reaches a maximum value at 20 degrees. Time-averaged flow visualization conducted at angles of attack of 20, 25 and 30 degrees shows vortices with larger magnitude that persist farther into wake are generated at higher angles of attack. These results compare analogously with similar steady baseline experiment results of high Reynolds number conducted by collaborators. This work was supported by the Office of Naval Research under ONR Award No. N00014-16-1-2732. We also acknowledge the collaborative support of Dr. David Rival and Mr. Matthew Marzanek at Queen's University.

General immunity and superadditivity of two-way Gaussian quantum cryptography

PubMed Central

Ottaviani, Carlo; Pirandola, Stefano

2016-01-01

We consider two-way continuous-variable quantum key distribution, studying its security against general eavesdropping strategies. Assuming the asymptotic limit of many signals exchanged, we prove that two-way Gaussian protocols are immune to coherent attacks. More precisely we show the general superadditivity of the two-way security thresholds, which are proven to be higher than the corresponding one-way counterparts in all cases. We perform the security analysis first reducing the general eavesdropping to a two-mode coherent Gaussian attack, and then showing that the superadditivity is achieved by exploiting the random on/off switching of the two-way quantum communication. This allows the parties to choose the appropriate communication instances to prepare the key, accordingly to the tomography of the quantum channel. The random opening and closing of the circuit represents, in fact, an additional degree of freedom allowing the parties to convert, a posteriori, the two-mode correlations of the eavesdropping into noise. The eavesdropper is assumed to have no access to the on/off switching and, indeed, cannot adapt her attack. We explicitly prove that this mechanism enhances the security performance, no matter if the eavesdropper performs collective or coherent attacks. PMID:26928053

Invasive plant species and the new bioeconomy

USDA-ARS?s Scientific Manuscript database

Simulation models of management effects on weed demography and the experience of successful organic and low-external-input farmers point in the same direction: long-term weed management success depends on diversified strategies that attack multiple weed life stages. In an era of declining research b...

Addressing Issues of Workplace Harassment: Counseling the Targets.

ERIC Educational Resources Information Center

Lewis, Jacqueline; Coursol, Diane; Wahl, Kay Herting

2002-01-01

Workplace harassment includes dysfunctional personal interactions characterized by bullying behaviors, personal attacks, and attempts to denigrate others. Targets of workplace harassment may experience stress, depression, low self-esteem, loss of sleep, and even posttraumatic stress disorder. Strategies that counselors can use to work effectively…

Combating terrorism : federal agencies' efforts to implement national policy and strategy

DOT National Transportation Integrated Search

1997-09-01

The threat of terrorist attacks against U.S. citizens and property both at home and abroad has been an issue of growing national concern. As requested, the General Accounting Office (GAO) reviewed U.S. efforts to combat terrorism. This report discuss...

Experimental Demonstration of Polarization Encoding Measurement-Device-Independent Quantum Key Distribution

NASA Astrophysics Data System (ADS)

Tang, Zhiyuan; Liao, Zhongfa; Xu, Feihu; Qi, Bing; Qian, Li; Lo, Hoi-Kwong

2014-05-01

We demonstrate the first implementation of polarization encoding measurement-device-independent quantum key distribution (MDI-QKD), which is immune to all detector side-channel attacks. Active phase randomization of each individual pulse is implemented to protect against attacks on imperfect sources. By optimizing the parameters in the decoy state protocol, we show that it is feasible to implement polarization encoding MDI-QKD with commercial off-the-shelf devices. A rigorous finite key analysis is applied to estimate the secure key rate. Our work paves the way for the realization of a MDI-QKD network, in which the users only need compact and low-cost state-preparation devices and can share complicated and expensive detectors provided by an untrusted network server.

Experimental demonstration of polarization encoding measurement-device-independent quantum key distribution.

PubMed

Tang, Zhiyuan; Liao, Zhongfa; Xu, Feihu; Qi, Bing; Qian, Li; Lo, Hoi-Kwong

2014-05-16

We demonstrate the first implementation of polarization encoding measurement-device-independent quantum key distribution (MDI-QKD), which is immune to all detector side-channel attacks. Active phase randomization of each individual pulse is implemented to protect against attacks on imperfect sources. By optimizing the parameters in the decoy state protocol, we show that it is feasible to implement polarization encoding MDI-QKD with commercial off-the-shelf devices. A rigorous finite key analysis is applied to estimate the secure key rate. Our work paves the way for the realization of a MDI-QKD network, in which the users only need compact and low-cost state-preparation devices and can share complicated and expensive detectors provided by an untrusted network server.

OPTIMIZATION OF INTEGRATED URBAN WET-WEATHER CONTROL STRATEGIES

EPA Science Inventory

An optimization method for urban wet weather control (WWC) strategies is presented. The developed optimization model can be used to determine the most cost-effective strategies for the combination of centralized storage-release systems and distributed on-site WWC alternatives. T...

Global Epidemiology of Plasmodium vivax

PubMed Central

Howes, Rosalind E.; Battle, Katherine E.; Mendis, Kamini N.; Smith, David L.; Cibulskis, Richard E.; Baird, J. Kevin; Hay, Simon I.

2016-01-01

Plasmodium vivax is the most widespread human malaria, putting 2.5 billion people at risk of infection. Its unique biological and epidemiological characteristics pose challenges to control strategies that have been principally targeted against Plasmodium falciparum. Unlike P. falciparum, P. vivax infections have typically low blood-stage parasitemia with gametocytes emerging before illness manifests, and dormant liver stages causing relapses. These traits affect both its geographic distribution and transmission patterns. Asymptomatic infections, high-risk groups, and resulting case burdens are described in this review. Despite relatively low prevalence measurements and parasitemia levels, along with high proportions of asymptomatic cases, this parasite is not benign. Plasmodium vivax can be associated with severe and even fatal illness. Spreading resistance to chloroquine against the acute attack, and the operational inadequacy of primaquine against the multiple attacks of relapse, exacerbates the risk of poor outcomes among the tens of millions suffering from infection each year. Without strategies accounting for these P. vivax-specific characteristics, progress toward elimination of endemic malaria transmission will be substantially impeded. PMID:27402513

Emergency response guidance for the first 48 hours after the outdoor detonation of an explosive radiological dispersal device.

PubMed

Musolino, Stephen V; Harper, Frederick T

2006-04-01

Strategies and decisions to protect emergency responders, the public, and critical infrastructure against the effects of a radiological dispersal device detonated outdoors must be made in the planning stage, not in the early period just after an attack. This contrasts with planning for small-scale types of radiological or nuclear emergencies, or for a large-scale nuclear-power-type accident that evolves over many hours or days before radioactivity is released to the environment, such that its effects can be prospectively modeled and analyzed. By the time it is known an attack has occurred, most likely there will have been casualties, all the radioactive material will have been released, plume growth will be progressing, and there will be no time left for evaluating possible countermeasures. This paper offers guidance to planners, first responders, and senior decision makers to assist them in developing strategies for protective actions and operational procedures for the first 48 hours after an explosive radiological dispersal device has been detonated.

"Asia is now the priority target for the world anti-tobacco movement": attempts by the tobacco industry to undermine the Asian anti-smoking movement

PubMed Central

Knight, J; Chapman, S

2004-01-01

Study objective: To identify and examine the strategies utilised by multinational tobacco companies to undermine and discredit key anti-tobacco activists and organisations in the Asian region. Method: A series of case studies drawing upon material gathered through systematic reviews of internal tobacco industry documents. Date sources: Tobacco industry documents made public as part of the settlement of the Minnesota Tobacco Trial and the Master Settlement Agreement. Results: The industry sought to identify, monitor, and isolate key individuals and organisations. The way industry went about fulfilling this mandate in the Asian region is discussed. Industry targetted individuals and agencies along with the region's primary anti-smoking coalition. Conclusions: Attack by multinational tobacco companies is a virtual quid pro quo for any individual or agency seriously challenging industry practices and policies. Understanding their tactics allows anticipatory strategies to be developed to minimise the effectiveness of these attacks. PMID:15564217

Children's affective reactions and coping under threat of missile attack: a semiprojective assessment procedure.

PubMed

Zeidner, M; Klingman, A; Itskowitz, R

1993-06-01

This study reports on 170 Israeli school children at risk for missile attack during the Persian Gulf War. The Bar-Ilan Picture Test for Children (Itskowitz & Strauss, 1982, 1986) was specially adapted to the war situation specifically to measure children's affective reactions and coping strategies. Children with a greater sense of control and social support, and more complex defenses, tended to demonstrate better coping strategies. Children who were less defensive showed higher levels of anxiety under stress. Children scoring higher in social support showed greater perceived control over their immediate environment and more verbal expressivity with respect to the crisis situation. Girls scored higher than boys on emotional and verbal expressiveness. These data, elicited through semiprojective procedures, are consistent with much of the prior research based mainly on objective scales or self-report questionnaires. Overall, the results lend additional validity to the nexus of relations (largely established through conventional objective scales) between resources, coping, and outcomes in a naturalistic stressor situation.

Battles between an insurgent army and an advanced army - focus on strategy

NASA Astrophysics Data System (ADS)

Sen, Surajit; Shanahan, Linda

2008-03-01

Detailed and aggregate analyses of the outcome of past battles focusing on rates of troop losses or on the ratios of forces on each side is at the heart of present knowledge about battles. Here we present non-equilibrium statistical mechanics based studies of possible outcomes of well matched strategic battles by a ``blue'' army against insurgency based attacks by well matched opponents in a ``red'' army in red territory. We assume that the red army attacks with randomly varying force levels to potentially confuse and drive the blue's strategies. The temporal evolution of the model battles incorporate randomness in the deployment of the reds and hence possess attendant history dependence. Our results reveal that while unpredictable events play a major role in battles, a balance between risk of exposure in a battlefield and the use of short range intelligence is needed in determining whether one side can decimate the other, and hence force a battle to end.