CiteULike: Tag hierarchy

Hierarchical Organization of Modularity in Metabolic Networks

E Ravasz — 2005-08-24T02:24:50-00:00

Science, Vol. 297, No. 5586. (30 August 2002), pp. 1551-1555.

The Three Ways of Getting Things Done: Hierarchy, Heterarchy and Responsible Autonomy in Organizations

Gerard Fairtlough — 2006-04-05T00:54:34-00:00

When Does "Economic Man" Dominate Social Behavior?

Colin Camerer — 2006-03-03T16:06:54-00:00

Science, Vol. 311, No. 5757. (6 January 2006), pp. 47-52.

The canonical model in economics considers people to be rational and self-regarding. However, much evidence challenges this view, raising the question of when "Economic Man" dominates the outcome of social interactions, and when bounded rationality or other-regarding preferences dominate. Here we show that strategic incentives are the key to answering this question. A minority of self-regarding individuals can trigger a "noncooperative" aggregate outcome if their behavior generates incentives for the majority of other-regarding individuals to mimic the minority's behavior. Likewise, a minority of other-regarding individuals can generate a "cooperative" aggregate outcome if their behavior generates incentives for a majority of self-regarding people to behave cooperatively. Similarly, in strategic games, aggregate outcomes can be either far from or close to Nash equilibrium if players with high degrees of strategic thinking mimic or erase the effects of others who do very little strategic thinking. Recently developed theories of other-regarding preferences and bounded rationality explain these findings and provide better predictions of actual aggregate behavior than does traditional economic theory.

A practical key management scheme for access control in a user hierarchy

S Zhong — 2007-11-09T15:27:55-00:00

(November 2002), pp. 750-759.

In a user hierarchy we say that a security class is subordinate to another security class if the former has a lower security privilege than the latter. To implement such a hierarchical structure, it is often desirable to allow the user of each security class to derive the keys of its subordinating classes. This problem has been extensively studied but the existing solutions have various drawbacks. In this paper, we present a practical solution to this problem, which is an efficient key management scheme that needs only a reasonable amount of extra storage. It is secure because illegal key derivations are prevented, and key replacements do not reveal information about the relationship between the old key and the new key. It is also very flexible in that it supports convenient topological changes and membership updates. Furthermore, it provides a solution to the ex-member problem, that has been ignored in many existing research works.

Cryptographic solution to a problem of access control in a hierarchy

Selim Akl — 2007-11-08T08:43:55-00:00

ACM Trans. Comput. Syst., Vol. 1, No. 3. (August 1983), pp. 239-248.

Cryptographic implementation of a tree hierarchy for access control

Ravinderpal Sandhu — 2007-11-09T15:35:45-00:00

Inf. Process. Lett., Vol. 27, No. 2. (February 1988), pp. 95-98.

The MAXQ method for hierarchical reinforcement learning

Thomas Dietterich — 2007-07-25T22:21:25-00:00

(1998), pp. 118-126.

This paper presents a new approach to hierarchical reinforcement learning based on the MAXQ decomposition of the value function. The MAXQ decomposition has both a procedural semantics---as a subroutine hierarchy---and a declarative semantics---as a representation of the value function of a hierarchical policy. MAXQ unifies and extends previous work on hierarchical reinforcement learning by Singh, Kaelbling, and Dayan and Hinton. Conditions under which the MAXQ decomposition can represent the...

Hierarchical structure and the prediction of missing links in networks

Aaron Clauset — 2008-04-30T19:31:59-00:00

Nature, Vol. 453, No. 7191., pp. 98-101.

Revisiting the Hierarchical Data Model

H Jagadish — 2008-05-03T15:03:52-00:00

(1999)

this paper, we develop a framework for a modern hierarchical data model, substantially improved from the original version by taking advantage of the lessons learned in the relational database context. We argue that this new hierarchical data model has many benets with respect to the ubiquitous at relational data model.

SDiff(2) KP hierarchy

Kanehisa Takasaki — 2007-11-30T14:56:29-00:00

(1 Feb 1993)

An analogue of the KP hierarchy, the SDiff(2) KP hierarchy, related to the group of area-preserving diffeomorphisms on a cylinder is proposed. An improved Lax formalism of the KP hierarchy is shown to give a prototype of this new hierarchy. Two important potentials, $S$ and $τ$, are introduced. The latter is a counterpart of the tau function of the ordinary KP hierarchy. A Riemann-Hilbert problem relative to the group of area-diffeomorphisms gives a twistor theoretical description (nonlinear graviton construction) of general solutions. A special family of solutions related to topological minimal models are identified in the framework of the Riemann-Hilbert problem. Further, infinitesimal symmetries of the hierarchy are constructed. At the level of the tau function, these symmetries obey anomalous commutation relations, hence leads to a central extension of the algebra of infinitesimal area-preserving diffeomorphisms (or of the associated Poisson algebra).

Heat kernel expansions on the integers and the Toda lattice hierarchy

Plamen Iliev — 2007-12-11T11:24:05-00:00

(7 Dec 2007)

We consider the heat equation $u_t=Lu$ where $L$ is a second-order difference operator in a discrete variable $n$. The fundamental solution has an expansion in terms of the Bessel functions of imaginary argument. The coefficients $α_k(n,m)$ in this expansion are analogs of Hadamard's coefficients for the (continuous) Schrodinger operator. We derive an explicit formula for $α_k$ in terms of the wave and the adjoint wave functions of the Toda lattice hierarchy. As a first application of this result, we prove that the values of these coefficients on the diagonals $n=m$ and $n=m+1$ define a hierarchy of differential-difference equations which is equivalent to the Toda lattice hierarchy. Using this fact and the correspondence between commutative rings of difference operators and algebraic curves we show that the fundamental solution can be summed up, giving a finite formula involving only two Bessel functions with polynomial coefficients in the time variable $t$, if and only if the operator $L$ belongs to the family of bispectral operators constructed in [18].

Matrix integrals, Toda symmetries, Virasoro constraints, and orthogonal polynomials

M Adler — 2007-11-05T11:31:55-00:00

Duke Math. J., Vol. 80, No. 3. (1995), pp. 863-911.

String-orthogonal polynomials, string equations, and $2$-Toda symmetries

Mark Adler — 2007-11-05T11:05:44-00:00

Comm. Pure Appl. Math., Vol. 50, No. 3. (1997), pp. 241-290.

Group factorization, moment matrices, and Toda lattices

M Adler — 2007-11-05T11:01:00-00:00

Internat. Math. Res. Notices, No. 12. (1997), pp. 555-572.

The extended bigraded Toda hierarchy

Guido Carlet — 2007-10-18T09:57:52-00:00

Journal of Physics A: Mathematical and General, Vol. 39, No. 30. (2006), pp. 9411-9435.

We generalize the Toda lattice hierarchy by considering N + M dependent variables. We construct roots and logarithms of the Lax operator which are uniquely defined operators with coefficients that are [?]-series of differential polynomials in the dependent variables, and we use them to provide a Lax pair definition of the extended bigraded Toda hierarchy, generalizing [4]. Using R-matrix theory we give the bi-Hamiltonian formulation of this hierarchy and we prove the existence of a tau function for its solutions. Finally we study the dispersionless limit and its connection with a class of Frobenius manifolds on the orbit space of the extended affine Weyl groups W^(N)(A_N+M-1) of the A series, defined by Dubrovin and Zhang (1998 Compos. Math. 111 167).

N=2 supersymmetric unconstrained matrix GNLS hierarchies are consistent

F Delduc — 2007-10-29T10:21:09-00:00

(8 Aug 2007)

We develop a pseudo-differential approach to the N=2 supersymmetric unconstrained matrix (k|n,m)-Generalized Nonlinear Schroedinger hierarchies and prove consistency of the corresponding Lax-pair representation (<a href="/abs/nlin.SI/0201026">nlin.SI/0201026</a>). Furthermore, we establish their equivalence to the integrable hierarchies derived in the super-algebraic approach of the homogeneously-graded loop superalgebra sl(2k+n|2k+m)⊗ C[lambda,lambda^-1] (<a href="/abs/nlin.SI/0206037">nlin.SI/0206037</a>). We introduce an unconventional definition of N=2 supersymmetric strictly pseudo-differential operators so as to close their algebra among themselves.

Temporal Hierarchical Control of Singing in Birds

Albert Yu — 2007-06-06T14:25:59-00:00

Science, Vol. 273, No. 5283. (27 September 1996), pp. 1871-1875.

10.1126/science.273.5283.1871

Discovering hierarchy in reinforcement learning with hexq

B Hengst — 2007-09-25T14:49:53-00:00

(2002)

An open problem in reinforcement learning is discovering hierarchical structure. HEXQ, an algorithm which automatically attempts to decompose and solve a model-free factored MDP hierarchically is described. By searching for aliased Markov sub-space regions based on the state variables the algorithm uses temporal and state abstraction to construct a hierarchy of interlinked smaller MDPs.

The Use of Multiplayer Game Theory in the Modeling of Biological Populations

M Broom — 2007-07-04T22:23:09-00:00

The use of game theory in modeling the natural world is widespread. However, this modeling mainly involves two player games only, or "playing the field" games where an individual plays against an entire (infinite) population. Game-theoretic models are common in economics as well, but in this case the use of multiplayer games has not been neglected. This article outlines where multiplayer games have been used in evolutionary modeling and the merits and limitations of these games. Finally, we discuss why there has been so little use of multiplayer games in the biological setting and what developments might be useful.

The Evolution of Social Dominance I: Two-player Models

GS Van Doorn — 2005-07-21T18:50:49-00:00

Behaviour, Vol. 140, No. 10. (2003), pp. 1305-1332.

A difference in dominance rank is an often-used cue to resolve conflicts between two animals without escalated fights. At the group level, adherence to a dominance convention efficiently reduces the costs associated with conflicts, but from an individual's point of view, it is difficult to explain why a low ranking individual should accept its subordinate status. This is especially true if, as suggested by several authors, dominance not necessarily reflects differences in fighting ability but rather results from arbitrary historical asymmetries. According to this idea, rank differentiation emerges from behavioural strategies, referred to as winner and loser effects, in which winners of previous conflicts are more likely to win the current conflict, whereas the losers of previous conflicts are less likely to do so. In order to investigate whether dominance, based on such winner and loser effects, can be evolutionarily stable, we analyse a game theoretical model. The model focuses on an extreme case in which there are no differences in fighting ability between individuals at all. The only asymmetries that may arise between individuals are generated by the outcome of previous conflicts. By means of numerical analysis, we find alternative evolutionarily stable strategies, which all utilize these asymmetries for conventional conflict resolution. One class of these strategies is based on winner and loser effects, thus generating evolutionarily stable dominance relations even in the absence of differences in resource holding potential.

The Evolution of Social Dominance II: Multi-Player Models

Sander Van Doorn — 2008-05-31T06:37:55-00:00

tilized for conventionalcon# ict resolution.Several evolutionarilystable strategiesare based on winner and loser effects and these strategies give rise to transitive hierarchies. Corresponding author's e-mail address: doorngs@biol.rug.nl The authors wish to thank Charlotte Hemelrijk, Bernard Thierry and an anonymous referee for their useful suggestions to improve the quality of the manuscript. Koninklijke Brill NV, Leiden, 2003 Behaviour 140, 1333-1358 Also available online - ...

Mathematical model of self-organizing hierarchies in animal societies

Eric Bonabeau — 2007-07-04T22:02:43-00:00

Bulletin of Mathematical Biology, Vol. 58, No. 4. (July 1996), pp. 661-717.

Abstract We propose a mathematical approach to the modelling of self-organizing hierarchies in animal societies. This approach relies on a basic positive feedback mechanism that reinforces the ability of a given individual to win or to lose in a hierarchical interaction, depending on how many times it won or lost in previous interactions. Motivated by experiments carried out on primitively eusocial waspsPolistes, the model, is based on coupled differential equations supplemented with a small stochastic term. Numerical integrations allow many different hierarchical profiles to be obtained depending on the model parameters: (1) the particular form of the probability for an individual to win or lose a fight given its history, (2) the probability of interaction between two individuals, (3) the forgetting strength, which determines the rate at which events in the past are forgotten and no longer influence the force of an individual and (4) two individual recognition parameters, which set the contribution of individual recognition in the process of hierarchical genesis. We compare the results, expressed in terms of a hierarchical index or of the Landau number that describes the degree of linearity of the hierarchy, with various experimental results.

Toward a theory of dominance hierarchies: effects of assessment, group size, and variation in fighting ability

Michael Mesterton-Gibbons — 2008-05-11T17:27:33-00:00

Behav. Ecol., Vol. 6, No. 4. (1 January 1995), pp. 416-423.

We introduce assessment to the analysis of dominance hierarchies by exploring the effect of an evolutionarily stable fighting rule when there is variation in resource holding potential (RHP) and RHP is not a perfectly reliable predictor of the outcome of a fight. With assessment, the probability of a linear hierarchy decreases with group size but can remain appreciable for groups of up to seven or eight individuals, whereas it decreases virtually to zero if there is no assessment. The probability of a hierarchy that correlates perfectly with RHP is low unless group size is small. 10.1093/beheco/6.4.416

Structures of power in naturally occurring communities

Levi — 2008-05-11T17:17:06-00:00

Social Networks, Vol. 20, No. 3. (July 1998), pp. 197-225.

This paper uses the sample of communes from Zablocki's study [Zablocki, Benjamin, 1980. Alienation and Charisma: A Study of Contemporary American Communes. The Free Press, New York] to test formal models of how interpersonal power relations are structured. Three alternative possibilities are explored--that observed power relations are derived from a single underlying status dimension, that they are derived from a differentiated status structure, and that there is no underlying structure at all. Some communes have latent status dimensions, others do not, but none have differentiated structures. Certain causes and effects of the production of such status orders are explored.

Graph theoretical dimensions of informal organizations

David Krackhardt — 2007-09-18T14:05:00-00:00

(1994), pp. 89-111.

A Hierarchical Model of Web Graph

Jie Han — 2008-03-21T03:59:34-00:00

Advanced Data Mining and Applications (2006), pp. 790-797.

The pages on the World Wide Web and their hyperlinks induce a huge directed graph – the Web Graph. Many models have been brought up to explain the static and dynamic properties of the graph. Most of them pay much attention to the pages without considering their essential relations. In fact, Web pages are well organized in Web sites as a tree hierarchy. In this paper, we propose a hierarchical model of Web graph which exploits both link structure and hierarchical relations of Web pages. The analysis of the model reveals many properties about the evolution of pages, sites and the relation among them.

Extracting the hierarchical organization of complex systems

Marta Sales-Pardo — 2007-09-28T11:11:46-00:00

Proceedings of the National Academy of Sciences, Vol. 104, No. 39. (25 September 2007), pp. 15224-15229.

Extracting understanding from the growing "sea" of biological and socioeconomic data is one of the most pressing scientific challenges facing us. Here, we introduce and validate an unsupervised method for extracting the hierarchical organization of complex biological, social, and technological networks. We define an ensemble of hierarchically nested random graphs, which we use to validate the method. We then apply our method to real-world networks, including the air-transportation network, an electronic circuit, an e-mail exchange network, and metabolic networks. Our analysis of model and real networks demonstrates that our method extracts an accurate multiscale representation of a complex system. 10.1073/pnas.0703740104

Why social dominance theory has been falsified

JC Turner — 2008-04-15T20:53:27-00:00

British Journal of Social Psychology (June 2003), pp. 199-206.

Schmitt, Branscombe and Kappen (2003) and Wilson and Lui (2003) present a persuasive series of studies which raise major problems for the conceptualization of social dominance orientation in social dominance theory. Building on these and other data in the literature, this commentary summarizes six fundamental criticisms which can be made of the theory. We conclude that social dominance theory is flawed by conceptual inconsistencies and has been disconfirmed empirically in relation to its key hypothesis of behavioural asymmetry. The reaction of subordinate groups to the social hierarchy is better explained by social identity theory.

Fish can infer social rank by observation alone

Logan Grosenick — 2007-01-25T23:40:59-00:00

Nature, Vol. 445, No. 7126., pp. 429-432.

Structural Inference of Hierarchies in Networks

Aaron Clauset — 2006-10-25T01:00:19-00:00

(9 Oct 2006)

One property of networks that has received comparatively little attention is hierarchy, i.e., the property of having vertices that cluster together in groups, which then join to form groups of groups, and so forth, up through all levels of organization in the network. Here, we give a precise definition of hierarchical structure, give a generic model for generating arbitrary hierarchical structure in a random graph, and describe a statistically principled way to learn the set of hierarchical features that most plausibly explain a particular real-world network. By applying this approach to two example networks, we demonstrate its advantages for the interpretation of network data, the annotation of graphs with edge, vertex and community properties, and the generation of generic null models for further hypothesis testing.

Functional Magnetic Resonance Imaging Evidence for a Hierarchical Organization of the Prefrontal Cortex.

David Badre — 2007-09-27T13:58:38-00:00

J Cogn Neurosci (24 September 2007)

Abstract The prefrontal cortex (PFC) is central to flexible and organized action. Recent theoretical and empirical results suggest that the rostro-caudal axis of the frontal lobes may reflect a hierarchical organization of control. Here, we test whether the rostro-caudal axis of the PFC is organized hierarchically, based on the level of abstraction at which multiple representations compete to guide selection of action. Four functional magnetic resonance imaging (fMRI) experiments parametrically manipulated the set of task-relevant (a) responses, (b) features, (c) dimensions, and (d) overlapping cue-to-dimension mappings. A systematic posterior to anterior gradient was evident within the PFC depending on the manipulated level of representation. Furthermore, across four fMRI experiments, activation in PFC subregions was consistent with the sub- and superordinate relationships that define an abstract representational hierarchy. In addition to providing further support for a representational hierarchy account of the rostro-caudal gradient in the PFC, these data provide important empirical constraints on current theorizing about control hierarchies and the PFC.

Hierarchical Structure in Financial Markets

Rosario Mantegna — 2007-03-20T09:16:24-00:00

(24 Feb 1998)

I find a topological arrangement of stocks traded in a financial market which has associated a meaningful economic taxonomy. The topological space is a graph connecting the stocks of the portfolio analyzed. The graph is obtained starting from the matrix of correlation coefficient computed between all pairs of stocks of the portfolio by considering the synchronous time evolution of the difference of the logarithm of daily stock price. The hierarchical tree of the subdominant ultrametric space associated with the graph provides information useful to investigate the number and nature of the common economic factors affecting the time evolution of logarithm of price of well defined groups of stocks.

Mobile robot autonomy via hierarchical fuzzy behavior control

E Tunstel — 2007-06-21T13:21:17-00:00

(1996), pp. 837-842.

Realization of autonomous behavior in mobile robots, using fuzzy logic control, requires formulation of rules which are collectively responsible for necessary levels of intelligence. This collection of rules can be conveniently decomposed and efficiently implemented as a hierarchy of fuzzy-behaviors. This paper describes how this can be done using a behavior-based architecture. The approach is motivated by ethological models which suggest hierarchical organizations of behavior. A behavior...

Towards Automatic Partitioning of Class Hierarchies

Heiner Stuckenschmidt — 2007-07-31T12:36:39-00:00

The increasing awareness of the benefits of ontologies for information processing has lead to the creation of a number of large ontologies about real world domains. The size of these ontologies and their monolithic character cause serious problems in handling them. In other areas, e.g. software engineering, these problems are tackled by partitioning monolithic entities into sets of meaningful and mostly self-contained modules. In this paper, we suggest a similar approach for ontologies. We...

Permissions and obligations in hierarchical normative systems

G Boella — 2007-06-10T16:45:04-00:00

(2003)

In this paper we discuss different types of permissions and their roles in deontic logic. We study the distinction between weak and strong permissions in the context of input/output logic, combining the logic with constraints, priorities and hierarchies of normative authorities. In this setting we observe that the notion of prohibition immunity no longer applies, and we introduce a new notion of permission as exception and a new distinction between static and dynamic norms. We show that strong...

Ultimate Computing

SR Hameroff — 2007-10-25T13:24:45-00:00

(01 August 1987)

Hierarchical reasoning: simulating complex processes over multiple levels of abstraction

Paul Fishwick — 2007-08-19T14:40:44-00:00

(1986)

A parameterised hierarchy of argumentation semantics for extended logic programming and its application to the well-founded semantics

Ralf Schweimeier — 2007-07-02T12:39:14-00:00

Theory Pract. Log. Program., Vol. 5, No. 1-2. (2005), pp. 207-242.

Lead-Lag Patterns Between Small and Large Size Portfolios in the London Stock Exchange

Terence And — 2007-12-15T21:49:09-00:00

this paper is to investigate whether similar lead-lag patterns hold between small and large firm portfolios from the London Stock Exchange. On finding that such patterns do exist, we then investigate the dynamic linkages between the portfolios using some recently developed techniques of time series econometrics, as these allow for a richer exploration of lead-lag patterns than do standard autocorrelation and cross-correlation analysis.

Feynman Clocks, Casual Networks, and the Origin of Hierarchical 'Arrows of Time' in Complex Systems from the Big Bang to the Brain

SM Hitchcock — 2007-11-01T14:27:27-00:00

ArXiv Quantum Physics e-prints (October 2000)

A theory of 'time' as a form of 'information' is proposed. New tools such as Feynman Clocks, Collective Excitation Networks, Sequential Excitation Networks, Plateaus of Complexity, and Causal Networks are used to unify previously separate 'arrows of time'.

Scale hierarchy created in plasma flow

Z Yoshida — 2006-09-06T17:55:26-00:00

Physics of Plasmas, Vol. 11, No. 7. (2004), pp. 3660-3664.

The cooperation of nonlinearity (producing collapsed characteristics) and dispersion (unfolding singularities) underlies a robust mechanism that imparts two distinct scales (L measuring the system size, and i typically of the order of the ion skin depth) to the double Beltrami states of a two-fluid plasma. It is shown that the conventional single-fluid model [magnetohydrodynamic (MHD)] seemingly valid for a large system (i/L0), fails to capture the small scale that is created by the singular perturbation of the two-fluid effect (dispersion). The small-scale component plays an important role in various plasma phenomena, such as coronal heating. The double Beltrami model is compared and contrasted with the standard MHD pathway (Parker's model of current sheet, for instance). ©2004 American Institute of Physics.

Hierarchies relating Topology and Geometry

Walter Yll — 2006-09-19T15:24:48-00:00

Cognitive Vision has to represent, reason and learn about objects in its environment it has to manipulate and react to. There are deformable objects like humans which cannot be described easily in simple geometric terms. In many cases they are composed of several pieces forming a "structured subset" of R or Z . We introduce the potential topological representations for structured objects: plane graphs, combinatorial and generalized maps. They capture abstract spatial relations...

Virial statistical description of non-extensive hierarchical systems

D Pfenniger — 2007-03-31T01:25:21-00:00

ArXiv Condensed Matter e-prints (May 2006)

In a first part the scope of classical thermodynamics and statistical mechanics is discussed in the broader context of formal dynamical systems, including computer programmes. In this context classical thermodynamics appears as a particular theory suited to a subset of all dynamical systems. A statistical mechanics similar to the one derived with the microcanonical ensemble emerges from dynamical systems provided it contains, 1) a finite non-integrable part of its phase space which is, 2) ergodic at a satisfactory degree after a finite time. The integrable part of phase space provides the constraints that shape the particular system macroscopical properties, and the chaotic part provides well behaved statistical properties over a relevant finite time. More generic semi-ergodic systems lead to intermittent behaviour, thus may be unsuited for a statistical description of steady states. Following these lines of thought, in a second part non-extensive hierarchical systems with statistical scale-invariance and power law interactions are explored. Only the virial constraint, consistent with their microdynamics, is included. No assumptions of classical thermodynamics are used, in particular extensivity and local homogeneity. In the limit of a large hierarchical range new constraints emerge in some conditions that depend on the interaction law range. In particular for the gravitational case, a velocity-site scaling relation is derived which is consistant with the ones empirically observed in the fractal interstellar medium.

Formal goal generation for intelligent control systems

Richard Dapoigny — 2006-11-21T08:31:42-00:00

(2005), pp. 712-721.

Hierarchical Selectivity for Object-based Visual Attention

Y Sun — 2006-09-18T11:12:37-00:00

(2002)

This paper presents a novel "hierarchical selectivity" mechanism for object-based visual attention. This mechanism integrates visual salience from bottom-up groupings and the top-down attentional setting. Under its guidance, covert visual attention can shift not only from one grouping to another but also from a grouping to its sub-groupings at a single resolution or multiple varying resolutions. Both object-based and space-based selection is integrated to give a visual attention mechanism ...

Hierarchical Monte Carlo methods for fractal random fields

Frank Elliott — 2007-02-03T12:40:51-00:00

Journal of Statistical Physics, Vol. V81, No. 3. (30 November 1995), pp. 717-736.

The Memory Evolutive Systems as a Model of Rosenâs Organisms â (Metabolic, Replication) Systems

Axiomathes, Vol. V16, No. 1. (15 March 2006), pp. 137-154.

An infinite hierarchy of temporal logics over branching time

Alexander Rabinovich — 2007-02-04T16:16:40-00:00

Inf. Comput., Vol. 171, No. 2. (December 2001), pp. 306-332.

The Theory of Incentives : The Principal-Agent Model

Jean-Jacques Laffont — 2005-02-27T16:26:00-00:00

(26 December 2001)

Economics has much to do with incentives--not least, incentives to work hard, to produce quality products, to study, to invest, and to save. Although Adam Smith amply confirmed this more than two hundred years ago in his analysis of sharecropping contracts, only in recent decades has a theory begun to emerge to place the topic at the heart of economic thinking. In this book, Jean-Jacques Laffont and David Martimort present the most thorough yet accessible introduction to incentives theory to date. Central to this theory is a simple question as pivotal to modern-day management as it is to economics research: What makes people act in a particular way in an economic or business situation? In seeking an answer, the authors provide the methodological tools to design institutions that can ensure good incentives for economic agents.<p>This book focuses on the principal-agent model, the "simple" situation where a principal, or company, delegates a task to a single agent through a contract--the essence of management and contract theory. How does the owner or manager of a firm align the objectives of its various members to maximize profits? Following a brief historical overview showing how the problem of incentives has come to the fore in the past two centuries, the authors devote the bulk of their work to exploring principal-agent models and various extensions thereof in light of three types of information problems: adverse selection, moral hazard, and non-verifiability. Offering an unprecedented look at a subject vital to industrial organization, labor economics, and behavioral economics, this book is set to become the definitive resource for students, researchers, and others who might find themselves pondering what contracts, and the incentives they embody, are really all about.

On Topological Hierarchies of Temporal Properties

Christel Baier — 2007-02-04T16:13:51-00:00

Fundamenta Informaticae, Vol. 41, No. 3. (2000), pp. 259-294.

. The classification of properties of concurrent programs into safety and liveness was first proposed by Lamport [20]. Since then several characterizations of hierarchies of properties have been given, see e.g. [4, 18, 8, 19]; this includes syntactic characterizations (in terms classes of formulas of logics such as the linear temporal logic) as well as extensional (as sets of computations in some abstract domain). The latter often admits a topological characterization with respect to the...