Incorporating the threat of terrorist attacks in the design of public service facility networks

In this paper, we consider the design problem of a public service facility network with existing facilities when there is a threat of possible terrorist attacks. The aim of the system planner, who is responsible for the operation of the network, is to open new facilities, relocate existing ones if necessary, and protect some of the facilities to ensure a maximum coverage of the demand that is assumed to be aggregated at customer zones. By doing so, the system planner anticipates that a number of unprotected facilities will be rendered out-of-service by terrorist attacks. It is assumed that the sum of the fixed cost of opening new facilities, the relocation costs, and the protection costs cannot exceed a predetermined budget level. Adopting the approach of gradual (or partial) coverage, we formulate a bilevel programming model where the system planner is the leader and the attacker is the follower. The objective of the former is the maximization of the total service coverage, whereas the latter wants to minimize it. We propose a heuristic solution procedure based on tabu search where the search space consists of the decisions of the system planner, and the corresponding objective value is computed by optimally solving the attacker??s problem using CPLEX. To assess the quality of the solutions produced by the tabu search (TS) heuristic, we also develop an exhaustive enumeration method, which explores all the possible combinations of opening new facilities, relocating existing ones, and protecting them. Since its time complexity is exponential, it can only be used for relatively small instances. Therefore, to be used as a benchmark method, we also implement a hill climbing procedure employed with the same type of moves as the TS heuristic. Besides, we carry out a sensitivity analysis on some of the problem parameters to investigate their effect on the solution characteristics.     

The development and interaction of terrorist and fanatic groups

Through the mathematical study of two models we quantify some of the theories of co-development and co-existence of focused groups in the social sciences. This work attempts to develop the mathematical framework behind the social sciences of community formation. By using well developed theories and concepts from ecology and epidemiology we hope to extend the theoretical framework of organizing and self-organizing social groups and communities, including terrorist groups. The main goal of our work is to gain insight into the role of recruitment and retention in the formation and survival of social organizations. Understanding the underlining mechanisms of the spread of ideologies under competition is a fundamental component of this work. Here contacts between core and non-core individuals extend beyond its physical meaning to include indirect interaction and spread of ideas through phone conversations, emails, media sources and other similar mean. This work focuses on the dynamics of formation of interest groups, either ideological, economical or ecological and thus we explore the questions such as, how do interest groups initiate and co-develop by interacting within a common environment and how do they sustain themselves? Our results show that building and maintaining the core group is essential for the existence and survival of an extreme ideology. Our research also indicates that in the absence of competitive ability (i.e., ability to take from the other core group or share prospective members) the social organization or group that is more committed to its group ideology and manages to strike the right balance between investment in recruitment and retention will prevail. Thus under no cross interaction between two social groups a single trade-off (of these efforts) can support only a single organization. The more efforts that an organization implements to recruit and retain its members the more effective it will be in transmitting the ideology to other vulnerable individuals and thus converting them to believers.     

The diffraction of Kelvin wave due to an island

This paper describes a numerical method to determine the diffraction effect of an oceanographic Kelvin wave system by an island. A standard shallow water approximation theory is assumed for the oceanographic equation. The problem is solved in two cases, when the island is elliptic and circular in shape and when it is far or near to the coastline, also when the island becomes narrow and perpendicular to an infinitely long coastline. Numerical computation of diffraction of the Kelvin waves has been calculated and plotted.     

The flow due to a rough rotating disk

Von Kármáns problem of a rotating disk in an infinite viscous fluid is extended to the case where the disk surface admits partial slip. The nonlinear similarity equations are integrated accurately for the full range of slip coefficients. The effects of slip are discussed. An existence proof is also given.     

The flow due to a rough rotating disk

Von Kármáns problem of a rotating disk in an infinite viscous fluid is extended to the case where the disk surface admits partial slip. The nonlinear similarity equations are integrated accurately for the full range of slip coefficients. The effects of slip are discussed. An existence proof is also given.     

Games of timing related to distribution of resources

The paper considers a class of zero-sum, two-person games which are related to distribution of resources. Each of the players is in possession of an amount of resource, to be distributed by him in the time interval [0, 1] according to an arbitrary measure. The payoff function is defined in such a manner that the games are a generalization of the so-called silent, nondiscrete duels. It is proven that these games have a value, and the optimal strategies for the players are found. The results of the paper bring to light new, essential elements, common to almost all games of timing on [0, 1].     

Cooperative game theoretic centrality analysis of terrorist networks: The cases of Jemaah Islamiyah and Al Qaeda

The identification of key players in a terrorist organization aids in preventing attacks, the efficient allocation of surveillance measures, and the destabilization of the corresponding network. In this paper, we introduce a game theoretic approach to identify key players in terrorist networks. In particular we use the Shapley value as a measure of importance in cooperative games that are specifically designed to reflect the context of the terrorist organization at hand. The advantage of this approach is that both the structure of the terrorist network, which usually reflects a communication and interaction structure, as well as non-network features, i.e., individual based parameters such as financial means or bomb building skills, can be taken into account. The application of our methodology to the analysis results in rankings of the terrorists in the network. We illustrate our methodology through two case studies: Jemaah Islamiyah’s Bali bombing and Al Qaedas 9/11 attack, which lead to new insights in the operational networks responsible for these attacks.     

The relevance of system dynamics to engineering systems design

With the recent advent of new technology using micro computers for the centralised monitoring of information, the scope for totally automatic, real time control of large engineering systems has been advanced. We are entering a period which, retrospectively, may well be seen as the era of control; where for the first time it is both feasible and necessary to design system in terms of the way in which they will be operated, as well as in the traditional terms of their capacity requirements. However, before such comprehensive design can be undertaken compatible advances are required in information usage technology.The purpose of this paper is to demonstrate how the subject of System Dynamics can be used to assist with this problem, though its capacity to model information feedback and hence to model and test alternative system control rules based on the information retrieved. This type of application in the hard system area of engineering provides a strong contrast to the more usual applications of System Dynamics in softer socio-economic systems.The problem described is taken from the coal mining industry and related to the design of large scale underground conveyor belt systems used for the clearance of coal from mines. The demonstration presented, therefore, concerns research in this field, but has considerable scope for application in the general area of large scale bulk handling system.Of particular importance in the results is an indication of the potential savings in physical capacity which can stem from the careful design and implementation of control in such systems.     

Location of terror response facilities: A game between state and terrorist

We study a leader follower game with two players: a terrorist and a state where the later one installs facilities that provide support in case of a terrorist attack. While the Terrorist attacks one of the metropolitan areas to maximize his utility, the State, which acts as a leader, installs the facilities such that the metropolitan area attacked is the one that minimizes her disutility (i.e., minimizes ‘loss’). We solve the problem efficiently for one facility and we formulate it as a mathematical programming problem for a general number of facilities. We demonstrate the problem via a case study of the 20 largest metropolitan areas in the United States.     

The dynamics of turbo-flow

Zusammenfassung Ausgehend von der Tatsache, dass eine Schaufelreihe äquivalent ist einem Kraft- und damit auch einem Wirbelfeld, wird der Begriff der Potential-Kraft-Strömung erweitert. Diese schliesst den «von Mises-Fall» ein, wenn das Euler-Integral im ganzen Feld konstant ist.Die Struktur des Wirbelfeldes, sowohl des freien als auch des gebundenen, wird analysiert. Das Problem der Turbinenströmung reduziert sich auf die Lösung von zwei partiellen Differentialgleichungen, für die ein vollständiger Satz von Randbedingungen gegeben ist; die Rechnung wird auf bekannte numerische Methoden zurückgeführt.Während die üblichen Rechnungsmethoden nur Eintritts- und Austrittsdiagramme liefern, erhalten wir hier die vollständige Geschwindigkeitsverteilung im ganzen Kraftfeld. Die Schaufelform wird angegeben, und es ist möglich, das Zusammenwirken verschiedener Entwurfsparameter zu untersuchen.

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Nomenclature

Symbol a a constantL ² T ^–2 - B blade surface 0 - C velocity vectorLT ^–1 - C speedLT ^–1 - C _a average axial velocityLT ^–1 - d diameterL - F force per unit massLT ^–2 - f blade shape function 0 - g angular momentum per unit mass (g=C r)L ² T ^–1 - h blade heightL - H Bernoulli's constant (stator)L ² T ^–2 - H ^* Bernoulli's constant (rotor)L ² T ^–2 - k a constantL ² T ^–2 - K a parameterL ^–1 T ^–2 - p pressureML ^–1 T ^–2 - r radius, distance from axisL - R ₀ outer radiusL - R _i hub or inner radiusL - s arc lengthL - t timeT - u a unit vector depending on use - W relative velocityLT ^–1 - load functionL ² T ^–2 - family of surfaces 0 - a parameter 0 - r-component of vorticityT ^–1 - -component of vorticityT ^–1 - angle or direction 0 - a parameter 0 - z-component of vorticityT ^–1 - the number 0 - densityML ^–3 - a functionL ^–1 T ^–1 - direction or angular coordinate in rotors 0 - stream functionL ³ T ^–1 - angular velocityT ^–1 - vorticity vectorT ^–1 - vorticityT ^–1 This work, finished in August 1953, was done while the author was at the Aircraft Gas Turbine Division of the General Electric Company, Cincinnati, Ohio.     

The round plume due to a falling point source of heat

Summary The natural convection due to a point source of heat, which falls with constant velocity, is given in the form of an asymptotic series.

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Zusammenfassung Die natürliche Konvektion einer Wärmequelle (die mit konstanter Geschwindigkeit fällt) wird in einer asymptotischen Reihe dargestellt.

     

Survival of systems with protection subject to two types of external attacks

We consider a large system that, due to its importance and (or) large economic value, should be protected from possible harmful attacks. The attacker executes two types of attacks modeled by the corresponding shock processes: those that target the repairable defense system and those that target the non-repairable ‘main’ system itself. The quality of the performance of the defense system, i.e., the ability to neutralize the attacks on the main system depends on its state defined by the accumulated damage. In order to obtain the survival probabilities for the main system, we develop a new class of state-dependent extreme shock models, where the accumulated damage caused by the shock process of one type affects the probability of failure from shocks of the other type.     

Combinatorial lemmas and applications to dynamics

The well-known combinatorial lemma of Karpovsky, Milman and Alon and a very recent one of Kerr and Li are extended. The obtained lemmas are applied to study the maximal pattern entropy introduced in the paper. It turns out that the maximal pattern entropy is equal to the supremum of sequence entropies over all sequences both in topological and measure-theoretical settings. Moreover, it is shown the maximal pattern entropy of any topological system is logk for some with k the maximal length of intrinsic sequence entropy tuples; and a zero-dimensional system has zero sequence entropy for any sequence if and only if the maximal pattern with respect to any open cover is of polynomial order.     

The entropy of Garfinkle-Horne dilaton black hole due to arbitrary spin fields

Using the membrane model which is based on brick wall model, we calculated the free energy and entropy of Garfinkle-Horne dilatonic black hole due to arbitrary spin fields. The result shows that the entropy of scalar field and the entropy of Fermionic field have similar formulas. There is only a coefficient between them.     

固定资产投资对产业结构变动的影响分析

产业结构提升是一国或地区经济素质的重要表现,在产业结构演变的过程中,固定资产投资起着推动和促进的作用。本文运用成分分析的基本原理,对1980年以来我国产业结构的变化以及与固定资产投资活动的关系进行了测算分析。主要内容包括:产业结构成分变动的描述,产业结构成分变动检验,产业结构与固定资产投资之间关系的成分回归模拟等。     

The sound field due to a periodic array of forced wave-bearing strips

A compressible fluid in a two-dimensional half-space (y >0) is bounded by a plane surface (y = 0) which is acousticallyhard except for a set of periodically arranged strips S_n givenby nd – a < x < nd + a, y = 0 with n = 0, 1, 2,....The velocity potential Re {(x, y)exp(–it)} satisfies theHelmholtz wave equation in the fluid region y>0, with /y= 0 on the plane y = 0, x S_n. The boundary condition on thepistons S_n is taken to have the form where the prescribed forcing function V(x) is the same on eachstrip, so that V(x + nd) = V(x), and the operators L and M arepolynomial functions of the second derivative ²/x². This boundarycondition includes the possibilities of an elastic plate, amembrane, or an impedance surface for S_n. When the separationdistance d is much greater than the strip width 2a and wavelength2/k, the problem is reduced to that of finding the potential_p due to a single piston S_o set in a rigid baffle, togetherwith a potential _c subject to a similar condition with forcingfunctions exp (ikx) in place of V(x). The problem is generalizedto allow for the possibility of a phased forcing function V(x),such that V(x + nd) = exp (ißnd)V(x), where ßis a given constant.     

The effective communication of system dynamics to improve insight and learning in management education

Experienced exponents of system dynamics in management education appreciate that feedback, non-linearities and delays are ubiquitous, and create difficulties for making intuitive judgements about the dynamic behaviour of business systems. They have applied much effort to solving this problem, offering simple, high-level causal mapping techniques to conceptualise dynamic issues, formal simulation modelling, and simulation-based learning environments. However, the use of these methods is still not extensive, and it is often disconnected from other management development pedagogies.System dynamics is ideally suited to operationalising certain concepts central to the management field, notably the resource-based and competence-based view of strategic management. However, three developments must be made if this potential is to be exploited. Firstly, system dynamics must connect with those established concepts and frameworks in the management field. Secondly, the barriers for managers to appreciate the power of system dynamics must be lowered, to make the method an integral part of the managerial mind-set. Thirdly, managers need help to climb the learning curve of understanding regarding the dynamic behaviour of the business systems they endeavour to manage, through a comprehensive set of resource-mapping and gaming simulation tools.This paper describes how these developments can be implemented, reports on experience of using the resulting learning devices and comments on possible future directions. There is an exciting opportunity for system dynamics to make a major contribution to a new strategy paradigm, based on a dynamic resource-system view of the firm, a perspective that can be extended to other fields in management and to non-business contexts.