Institute of Scientific and Technical Information of China (English)
Zhi-Hong Tao; Cong-Hua Zhou; Zhong Chen; Li-Fu Wang
2007-01-01
Bounded Model Checking has been recently introduced as an efficient verification method for reactive systems.This technique reduces model checking of linear temporal logic to propositional satisfiability.In this paper we first present how quantified Boolean decision procedures can replace BDDs.We introduce a bounded model checking procedure for temporal logic CTL* which reduces model checking to the satisfiability of quantified Boolean formulas.Our new technique avoids the space blow up of BDDs, and extends the concept of bounded model checking.
A PSL Bounded Model Checking Method
Institute of Scientific and Technical Information of China (English)
YU Lei; ZHAO Zongtao
2012-01-01
SAT-based bounded model checking （BMC） is introduced as an important complementary technique to OBDD-based symbolic model checking, and is an efficient verification method for parallel and reactive systems. However, until now the properties verified by bounded model checking are very finite. Temporal logic PSL is a property specification language （IEEE-1850） describing parallel systems and is divided into two parts, i.e. the linear time logic FL and the branch time logic OBE. In this paper, the specification checked by BMC is extended to PSL and its algorithm is also proposed. Firstly, define the bounded semantics of PSL, and then reduce the bounded semantics into SAT by translating PSL specification formula and the state transition relation of the system to the propositional formula A and B, respectively. Finally, verify the satisfiability of the conjunction propositional formula of A and B. The algorithm results in the translation of the existential model checking of the temporal logic PSL into the satisfiability problem of propositional formula. An example of a queue controlling circuit is used to interpret detailedly the executing procedure of the algorithm.
A Metric Encoding for Bounded Model Checking
Pradella, Matteo; Morzenti, Angelo; San Pietro, Pierluigi
In Bounded Model Checking, both the system model and the checked property are translated into a Boolean formula to be analyzed by a SAT-solver. We introduce a new encoding technique which is particularly optimized for managing quantitative future and past metric temporal operators, typically found in properties of hard real time systems. The encoding is simple and intuitive in principle, but it is made more complex by the presence, typical of the Bounded Model Checking technique, of backward and forward loops used to represent an ultimately periodic infinite domain by a finite structure. We report and comment on the new encoding technique and on an extensive set of experiments carried out to assess its feasibility and effectiveness.
Bounded Model Checking of Temporal Formulas with Alloy
Cunha, Alcino
2012-01-01
Alloy is formal modeling language based on first-order relational logic, with no specific support for specifying reactive systems. We propose the usage of temporal logic to specify such systems, and show how bounded model checking can be performed with the Alloy Analyzer.
A Metric Encoding for Bounded Model Checking (extended version)
Pradella, Matteo; Pietro, Pierluigi San
2009-01-01
In Bounded Model Checking both the system model and the checked property are translated into a Boolean formula to be analyzed by a SAT-solver. We introduce a new encoding technique which is particularly optimized for managing quantitative future and past metric temporal operators, typically found in properties of hard real time systems. The encoding is simple and intuitive in principle, but it is made more complex by the presence, typical of the Bounded Model Checking technique, of backward and forward loops used to represent an ultimately periodic infinite domain by a finite structure. We report and comment on the new encoding technique and on an extensive set of experiments carried out to assess its feasibility and effectiveness.
Applied Bounded Model Checking for Interlocking System Designs
DEFF Research Database (Denmark)
Haxthausen, Anne Elisabeth; Peleska, Jan; Pinger, Ralf
2013-01-01
In this article the verification and validation of interlocking systems is investigated. Reviewing both geographical and route-related interlocking, the verification objectives can be structured from a perspective of computer science into (1) verification of static semantics, and (2) verification...... of behavioural (operational) semantics. The former checks that the plant model – that is, the software components reflecting the physical components of the interlocking system – has been set up in an adequate way. The latter investigates trains moving through the network, with the objective to uncover potential...... safety violations. From a formal methods perspective, these verification objectives can be approached by theorem proving, global, or bounded model checking. This article explains the techniques for application of bounded model checking techniques, and discusses their advantages in comparison...
Applied Bounded Model Checking for Interlocking System Designs
DEFF Research Database (Denmark)
Haxthausen, Anne Elisabeth; Peleska, Jan; Pinger, Ralf
2014-01-01
In this paper the verification and validation of interlocking systems is investigated. Reviewing both geographical and route-related interlocking, the verification objectives can be structured from a perspective of computer science into (1) verification of static semantics, and (2) verification of...... behavioural (operational) semantics. The former checks that the plant model – that is, the software components reflecting the physical components of the interlocking system – has been set up in an adequate way. The latter investigates trains moving through the network, with the objective to uncover potential...... safety violations. From a formal methods perspective, these verification objectives can be approached by theorem proving, global, or bounded model checking. This paper explains the techniques for application of bounded model checking techniques, and discusses their advantages in comparison to the...
Improved Bounded Model Checking for the Universal Fragment of CTL
Institute of Scientific and Technical Information of China (English)
Liang Xu; Wei Chen; Yan-Yan Xu; Wen-Hui Zhang
2009-01-01
SAT-based bounded model checking (BMC) has been introduced as a complementary technique to BDD-based symbolic model checking in recent years, and a lot of successful work has been done in this direction. The approach was first introduced by A. Biere et al. in checking linear temporal logic (LTL) formulae and then also adapted to check formulae of the universal fragment of computation tree logic (ACTL) by W. Penczek et al. As the efficiency of model checking is still an important issue, we present an improved BMC approach for ACTL based on Penczek's method. We consider two aspects of the approach. One is reduction of the number of variables and transitions in the k-model by distinguishing the temporal operator EX from the others. The other is simplification of the transformation of formulae by using uniform path encoding instead of a disjunction of all paths needed in the k-model. With these improvements, for an ACTI, formula, the length of the final encoding of the formula in the worst case is reduced. The improved approach is implemented in the tool BMV and is compared with the original one by applying both to two well known examples, mutual exclusion and dining philosophers. The comparison shows the advantages of the improved approach with respect to the efficiency of model checking.
Correctness of Sensor Network Applications by Software Bounded Model Checking
Werner, Frank; Faragó, David
We investigate the application of the software bounded model checking tool CBMC to the domain of wireless sensor networks (WSNs). We automatically generate a software behavior model from a network protocol (ESAWN) implementation in a WSN development and deployment platform (TinyOS), which is used to rigorously verify the protocol. Our work is a proof of concept that automatic verification of programs of practical size (≈ 21 000 LoC) and complexity is possible with CBMC and can be integrated into TinyOS. The developer can automatically check for pointer dereference and array index out of bound errors. She can also check additional, e.g., functional, properties that she provides by assume- and assert-statements. This experience paper shows that our approach is in general feasible since we managed to verify about half of the properties. We made the verification process scalable in the size of the code by abstraction (eg, from hardware) and by simplification heuristics. The latter also achieved scalability in data type complexity for the properties that were verifiable. The others require technical advancements for complex data types within CBMC's core.
SMT-based Bounded Model Checking with Difference Logic Constraints
Bersani, Marcello M; Morzenti, Angelo; Pradella, Matteo; Rossi, Matteo; Pietro, Pierluigi San
2010-01-01
Traditional Bounded Model Checking (BMC) is based on translating the model checking problem into SAT, the Boolean satisfiability problem. This paper introduces an encoding of Linear Temporal Logic with Past operators (PLTL) into the Quantifier-Free Difference Logic with Uninterpreted Functions (QF-UFIDL). The resulting encoding is a simpler and more concise version of existing SATbased encodings, currently used in BMC. In addition, we present an extension of PLTL augmented with arithmetic relations over integers, which can express unbounded counters; as such, the extended logic is more expressive than PLTL. We introduce suitable restrictions and assumptions that are shown to make the verification problem for the extended logic decidable, and we define an encoding of the new logic into QF-UFIDL. Finally, a performance comparison with the SAT-based approach on purely PLTL examples shows significant improvements in terms of both execution time and memory occupation.
Efficient Proof Engines for Bounded Model Checking of Hybrid Systems
DEFF Research Database (Denmark)
Fränzle, Martin; Herde, Christian
2005-01-01
In this paper we present HySat, a new bounded model checker for linear hybrid systems, incorporating a tight integration of a DPLL-based pseudo-Boolean SAT solver and a linear programming routine as core engine. In contrast to related tools like MathSAT, ICS, or CVC, our tool exploits all of the...
Local Model Checking of Weighted CTL with Upper-Bound Constraints
DEFF Research Database (Denmark)
Jensen, Jonas Finnemann; Larsen, Kim Guldstrand; Srba, Jiri; Østergaard, Lars
We present a symbolic extension of dependency graphs by Liu and Smolka in order to model-check weighted Kripke structures against the logic CTL with upper-bound weight constraints. Our extension introduces a new type of edges into dependency graphs and lifts the computation of fixed-points from...... boolean domain to nonnegative integers in order to cope with the weights. We present both global and local algorithms for the fixed-point computation on symbolic dependency graphs and argue for the advantages of our approach compared to the direct encoding of the model checking problem into dependency...
SMT-Based Bounded Model Checking for Embedded ANSI-C Software
Cordeiro, Lucas; Marques-Silva, Joao
2009-01-01
Propositional bounded model checking has been applied successfully to verify embedded software but is limited by the increasing propositional formula size and the loss of structure during the translation. These limitations can be reduced by encoding word-level information in theories richer than propositional logic and using SMT solvers for the generated verification conditions. Here, we investigate the application of different SMT solvers to the verification of embedded software written in ANSI-C. We have extended the encodings from previous SMT-based bounded model checkers to provide more accurate support for finite variables, bit-vector operations, arrays, structures, unions and pointers. We have integrated the CVC3, Boolector, and Z3 solvers with the CBMC front-end and evaluated them using both standard software model checking benchmarks and typical embedded applications from telecommunications, control systems and medical devices. The experiments show that our approach can analyze larger problems and sub...
Continuous Verification of Large Embedded Software using SMT-Based Bounded Model Checking
Cordeiro, Lucas; Marques-Silva, Joao
2009-01-01
The complexity of software in embedded systems has increased significantly over the last years so that software verification now plays an important role in ensuring the overall product quality. In this context, SAT-based bounded model checking has been successfully applied to discover subtle errors, but for larger applications, it often suffers from the state space explosion problem. This paper describes a new approach called continuous verification to detect design errors as quickly as possible by looking at the Software Configuration Management (SCM) system and by combining dynamic and static verification to reduce the state space to be explored. We also give a set of encodings that provide accurate support for program verification and use different background theories in order to improve scalability and precision in a completely automatic way. A case study from the telecommunications domain shows that the proposed approach improves the error-detection capability and reduces the overall verification time by...
Bounded Model Checking and Inductive Verification of Hybrid Discrete-Continuous Systems
DEFF Research Database (Denmark)
Becker, Bernd; Behle, Markus; Eisenbrand, Fritz;
2004-01-01
verication, bounded plan- ning and heuristic search, combinatorial optimization and integer programming. Af- ter sketching the overall verication ow we present rst results indicating that the combination and tight integration of dierent verication engines is a rst step to pave the way to fully automated BMC...
Model composition in model checking
Felscher, Ingo
2014-01-01
Model-checking allows one to formally check properties of systems: these properties are modeled as logic formulas and the systems as structures like transition systems. These transition systems are often composed, i.e., they arise in form of products or sums. The composition technique allows us to deduce the truth of a formula in the composed system from "interface information": the truth of formulas for the component systems and information in which components which of these formulas hold. W...
Compositional and Quantitative Model Checking
DEFF Research Database (Denmark)
Larsen, Kim Guldstrand
This paper gives a survey of a composition model checking methodology and its succesfull instantiation to the model checking of networks of finite-state, timed, hybrid and probabilistic systems with respect; to suitable quantitative versions of the modal mu-calculus [Koz82]. The method is based on...
Model Checking Is Static Analysis of Modal Logic
DEFF Research Database (Denmark)
Nielson, Flemming; Nielson, Hanne Riis
2010-01-01
it can give an exact characterisation of the semantics of formulae in a modal logic. This shows that model checking can be performed by means of state-of-the-art approaches to static analysis and allow us to conclude that the problems of model checking and static analysis are reducible to each other....... In terms of computational complexity we show that model checking by means of static analysis gives the same complexity bounds as are known for traditional approaches to model checking....
Model Checking as Static Analysis
DEFF Research Database (Denmark)
Zhang, Fuyuan
properties which can predict safe approximations to program behaviors. In this thesis, we have developed several static analysis based techniques to solve model checking problems, aiming at showing the link between static analysis and model checking. We focus on logical approaches to static analysis......Both model checking and static analysis are prominent approaches to detecting software errors. Model Checking is a successful formal method for verifying properties specified in temporal logics with respect to transition systems. Static analysis is also a powerful method for validating program...... multi-valued setting, and we therefore obtain a multivalued analysis for temporal properties specied by CTL formulas. In particular, we have shown that the three-valued CTL model checking problem over Kripke modal transition systems can be exactly encoded in three-valued ALFP. Last, we come back to two...
Checking Model Transformation Refinement
Büttner, Fabian; Egea, Marina; Guerra, Esther; Lara, Juan De
2013-01-01
The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-38883-5_15 Proceedings of 6th International Conference, ICMT 2013, Budapest, Hungary, June 18-19, 2013 Refinement is a central notion in computer science, meaning that some artefact S can be safely replaced by a refinement R, which preserves S’s properties. Having available techniques and tools to check transformation refinement would enable (a) the reasoning on whether a transformation correctly impl...
Model Checking Algorithms for CTMDPs
DEFF Research Database (Denmark)
Buchholz, Peter; Hahn, Ernst Moritz; Hermanns, Holger;
2011-01-01
Continuous Stochastic Logic (CSL) can be interpreted over continuoustime Markov decision processes (CTMDPs) to specify quantitative properties of stochastic systems that allow some external control. Model checking CSL formulae over CTMDPs requires then the computation of optimal control strategie...
Advances in Probabilistic Model Checking
Kwiatkowska, Marta; Parker, David
2012-01-01
Probabilistic model checking is an automated verification method that aims to establish the correctness of probabilistic systems. Probability may arise, for example, due to failures of unreliable components, communication across lossy media, or through the use of randomisation in distributed protocols. Probabilistic model checking enables a range of exhaustive, quantitative analyses of properties such as "the probability of a message being delivered within 5ms is at least 0.89". In the last t...
Model checking PSL safety properties
Launiainen, Tuomas
2009-01-01
Model checking is a modern, efficient approach to gaining confidence of the correctness of complex systems. It outperforms conventional testing methods especially in cases where a high degree of confidence in the correctness of the system is required, or when the test runs of the system are difficult to reproduce accurately. In model checking the system is verified against a specification that is expressed in a formal specification language. The main challenges are that the process requires q...
Jansen, D.N.
2002-01-01
The logic ATCTL is a convenient logic to specify properties with actions and real-time. It is intended as a property language for Lightweight UML models [12], which consist mainly of simplified class diagrams and statecharts. ATCTL combines two known extensions of CTL, namely ACTL and TCTL. The reas
Direct Model Checking Matrix Algorithm
Institute of Scientific and Technical Information of China (English)
Zhi-Hong Tao; Hans Kleine Büning; Li-Fu Wang
2006-01-01
During the last decade, Model Checking has proven its efficacy and power in circuit design, network protocol analysis and bug hunting. Recent research on automatic verification has shown that no single model-checking technique has the edge over all others in all application areas. So, it is very difficult to determine which technique is the most suitable for a given model. It is thus sensible to apply different techniques to the same model. However, this is a very tedious and time-consuming task, for each algorithm uses its own description language. Applying Model Checking in software design and verification has been proved very difficult. Software architectures (SA) are engineering artifacts that provide high-level and abstract descriptions of complex software systems. In this paper a Direct Model Checking (DMC) method based on Kripke Structure and Matrix Algorithm is provided. Combined and integrated with domain specific software architecture description languages (ADLs), DMC can be used for computing consistency and other critical properties.
A k-Bounded Symbolic Execution for Checking Strong Heap Properties of Open Systems
DEFF Research Database (Denmark)
Lee, Jooyong; Deng, Xianghua; Bogor, Robby
2006-01-01
strong heap properties, and it is fully automatic and flexible in terms of its cost and the guarantees it provides. It allows a user-adjustable mixed compositional/non-compositional reasoning and naturally produces error traces as fault evidence. We implemented Kiasan using the Bogor model checking......This paper presents Kiasan, a bounded technique to reason about open systems based on a path sensitive, relatively sound and complete symbolic execution instead of the usual compositional reasoning through weakest precondition calculation that summarizes all execution paths. Kiasan is able to check...
Institute of Scientific and Technical Information of China (English)
刘怡文; 李伟琴
2002-01-01
Strand Spaces serve as a model of security protocol analysis. In this paper, the main characteristics of Strand Spaces are briefly introduced, and its advantages and disadvantages are presented . An algorithm of building an ideal model of a protocol is proposed, which is used to bound both the abilities of the penetrator and the number of concurrent protocol runs. Combining Model Checking and Strand Spaces, a method is proposed to use both the automatic reasoning mechanism of the Model Checking and the bounds on security protocol analysis to achieve effective analysis of security protocols, avoiding state explosion problems.%Strand Spaces是一种用于分析安全协议的机器证明方法.简要介绍了Strand Spaces的基本特点,分析了其优劣,提出了构造协议的理想子环的算法,并以此来约束协议入侵者的能力和协议并行运行的次数.将模型检查与Strand Spaces结合在一起,提出了一种综合分析方法来验证协议的安全特性,该方法可充分发挥模型检查与Strand Spaces二者的优势.
Bounding species distribution models
Institute of Scientific and Technical Information of China (English)
Thomas J. STOHLGREN; Catherine S. JARNEVICH; Wayne E. ESAIAS; Jeffrey T. MORISETTE
2011-01-01
Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern.Many investigators now recognize that extrapolations of these models with geographic information systems (GIS) might be sensitive to the environmental bounds of the data used in their development,yet there is no recommended best practice for “clamping” model extrapolations.We relied on two commonly used modeling approaches:classification and regression tree (CART) and maximum entropy (Maxent) models,and we tested a simple alteration of the model extrapolations,bounding extrapolations to the maximum and minimum values of primary environmental predictors,to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States.Findings suggest that multiple models of bounding,and the most conservative bounding of species distribution models,like those presented here,should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 (5):642-647,2011].
From model checking to model measuring
Henzinger, Thomas A.; Otop, Jan
2013-01-01
We define the model-measuring problem: given a model $M$ and specification~$\\varphi$, what is the maximal distance $\\rho$ such that all models $M'$ within distance $\\rho$ from $M$ satisfy (or violate)~$\\varphi$. The model measuring problem presupposes a distance function on models. We concentrate on automatic distance functions, which are defined by weighted automata. The model-measuring problem subsumes several generalizations of the classical model-checking problem, in particular, qu...
Heteroscedasticity checks for regression models
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
For checking on heteroscedasticity in regression models, a unified approach is proposed to constructing test statistics in parametric and nonparametric regression models. For nonparametric regression, the test is not affected sensitively by the choice of smoothing parameters which are involved in estimation of the nonparametric regression function. The limiting null distribution of the test statistic remains the same in a wide range of the smoothing parameters. When the covariate is one-dimensional, the tests are, under some conditions, asymptotically distribution-free. In the high-dimensional cases, the validity of bootstrap approximations is investigated. It is shown that a variant of the wild bootstrap is consistent while the classical bootstrap is not in the general case, but is applicable if some extra assumption on conditional variance of the squared error is imposed. A simulation study is performed to provide evidence of how the tests work and compare with tests that have appeared in the literature. The approach may readily be extended to handle partial linear, and linear autoregressive models.
Heteroscedasticity checks for regression models
Institute of Scientific and Technical Information of China (English)
ZHU; Lixing
2001-01-01
［1］Carroll, R. J., Ruppert, D., Transformation and Weighting in Regression, New York: Chapman and Hall, 1988.［2］Cook, R. D., Weisberg, S., Diagnostics for heteroscedasticity in regression, Biometrika, 1988, 70: 1—10.［3］Davidian, M., Carroll, R. J., Variance function estimation, J. Amer. Statist. Assoc., 1987, 82: 1079—1091.［4］Bickel, P., Using residuals robustly I: Tests for heteroscedasticity, Ann. Statist., 1978, 6: 266—291.［5］Carroll, R. J., Ruppert, D., On robust tests for heteroscedasticity, Ann. Statist., 1981, 9: 205—209.［6］Eubank, R. L., Thomas, W., Detecting heteroscedasticity in nonparametric regression, J. Roy. Statist. Soc., Ser. B, 1993, 55: 145—155.［7］Diblasi, A., Bowman, A., Testing for constant variance in a linear model, Statist. and Probab. Letters, 1997, 33: 95—103.［8］Dette, H., Munk, A., Testing heteoscedasticity in nonparametric regression, J. R. Statist. Soc. B, 1998, 60: 693—708.［9］Müller, H. G., Zhao, P. L., On a semi-parametric variance function model and a test for heteroscedasticity, Ann. Statist., 1995, 23: 946—967.［10］Stute, W., Manteiga, G., Quindimil, M. P., Bootstrap approximations in model checks for regression, J. Amer. Statist. Asso., 1998, 93: 141—149.［11］Stute, W., Thies, G., Zhu, L. X., Model checks for regression: An innovation approach, Ann. Statist., 1998, 26: 1916—1939.［12］Shorack, G. R., Wellner, J. A., Empirical Processes with Applications to Statistics, New York: Wiley, 1986.［13］Efron, B., Bootstrap methods: Another look at the jackknife, Ann. Statist., 1979, 7: 1—26.［14］Wu, C. F. J., Jackknife, bootstrap and other re-sampling methods in regression analysis, Ann. Statist., 1986, 14: 1261—1295.［15］H rdle, W., Mammen, E., Comparing non-parametric versus parametric regression fits, Ann. Statist., 1993, 21: 1926—1947.［16］Liu, R. Y., Bootstrap procedures under some non-i.i.d. models, Ann. Statist., 1988, 16: 1696—1708.［17
The model checking fingerprints of CTL operators
Krebs, Andreas; Meier, Arne; Mundhenk, Martin
2015-01-01
The aim of this study is to understand the inherent expressive power of CTL operators. We investigate the complexity of model checking for all CTL fragments with one CTL operator and arbitrary Boolean operators. This gives us a fingerprint of each CTL operator. The comparison between the fingerprints yields a hierarchy of the operators that mirrors their strength with respect to model checking.
Program Analysis as Model Checking
DEFF Research Database (Denmark)
Olesen, Mads Chr.
of an abstract interpretation. For the generalisation to lattice automata to have benefit it is important that efficient tools exist. This thesis presents multi-core tools for efficient and scalable reachability and Büchi emptiness checking of timed/lattice automata. Finally, a number of case studies...... overapproximation of the hardware is needed; the case of identifying timing anomalous hardware for which such abstractions are hard to find is considered....
Engineering Abstractions in Model Checking and Testing
Achenbach, Michael; Ostermann, Klaus
2009-01-01
Abstractions are used in model checking to tackle problems like state space explosion or modeling of IO. The application of these abstractions in real software development processes, however, lacks engineering support. This is one reason why model checking is not widely used in practice yet and testing is still state of the art in falsification. We show how user-defined abstractions can be integrated into a Java PathFinder setting with tools like AspectJ or Javassist and discuss implicati...
Model Checking Discounted Temporal Properties
Alfaro, de Luca; Faella, Marco; Henzinger, Thomas A.; Majumdar, Rupak; Stoelinga, Mariëlle
2004-01-01
Temporal logic is two-valued: formulas are interpreted as either true or false. When applied to the analysis of stochastic systems, or systems with imprecise formal models, temporal logic is therefore fragile: even small changes in the model can lead to opposite truth values for a specification. We
Model Checking Discounted Temporal Properties
Alfaro, de Luca; Faella, Marco; Henzinger, Thomas A.; Majumdar, Rupak; Stoelinga, Mariëlle
2005-01-01
Temporal logic is two-valued: formulas are interpreted as either true or false. When applied to the analysis of stochastic systems, or systems with imprecise formal models, temporal logic is therefore fragile: even small changes in the model can lead to opposite truth values for a specification. We
Model Checking Implantable Cardioverter Defibrillators
Abbas, Houssam; Jang, Kuk Jin; Jiang, Zhihao; Mangharam, Rahul
2015-01-01
Ventricular Fibrillation is a disorganized electrical excitation of the heart that results in inadequate blood flow to the body. It usually ends in death within seconds. The most common way to treat the symptoms of fibrillation is to implant a medical device, known as an Implantable Cardioverter Defibrillator (ICD), in the patient's body. Model-based verification can supply rigorous proofs of safety and efficacy. In this paper, we build a hybrid system model of the human heart+ICD closed loop...
Graded CTL Model Checking for Test Generation
Napoli, Margherita
2011-01-01
Recently there has been a great attention from the scientific community towards the use of the model-checking technique as a tool for test generation in the simulation field. This paper aims to provide a useful mean to get more insights along these lines. By applying recent results in the field of graded temporal logics, we present a new efficient model-checking algorithm for Hierarchical Finite State Machines (HSM), a well established symbolism long and widely used for representing hierarchical models of discrete systems. Performing model-checking against specifications expressed using graded temporal logics has the peculiarity of returning more counterexamples within a unique run. We think that this can greatly improve the efficacy of automatically getting test cases. In particular we verify two different models of HSM against branching time temporal properties.
Engineering Abstractions in Model Checking and Testing
DEFF Research Database (Denmark)
Achenbach, Michael; Ostermann, Klaus
2009-01-01
Abstractions are used in model checking to tackle problems like state space explosion or modeling of IO. The application of these abstractions in real software development processes, however, lacks engineering support. This is one reason why model checking is not widely used in practice yet and...... testing is still state of the art in falsification. We show how user-defined abstractions can be integrated into a Java PathFinder setting with tools like AspectJ or Javassist and discuss implications of remaining weaknesses of these tools. We believe that a principled engineering approach to designing...
Model Checking Classes of Metric LTL Properties of Object-Oriented Real-Time Maude Specifications
Erika Ábrahám; Peter Csaba Ölveczky; Daniela Lepri
2010-01-01
This paper presents a transformational approach for model checking two important classes of metric temporal logic (MTL) properties, namely, bounded response and minimum separation, for nonhierarchical object-oriented Real-Time Maude specifications. We prove the correctness of our model checking algorithms, which terminate under reasonable non-Zeno-ness assumptions when the reachable state space is finite. These new model checking features have been integrated into Real-Time Maude, and are use...
Statistical Model Checking for Biological Systems
DEFF Research Database (Denmark)
David, Alexandre; Larsen, Kim Guldstrand; Legay, Axel;
2014-01-01
Statistical Model Checking (SMC) is a highly scalable simulation-based verification approach for testing and estimating the probability that a stochastic system satisfies a given linear temporal property. The technique has been applied to (discrete and continuous time) Markov chains, stochastic...
Using chemical organization theory for model checking
Kaleta, Christoph; Richter, Stephan; Dittrich, Peter
2009-01-01
Motivation: The increasing number and complexity of biomodels makes automatic procedures for checking the models' properties and quality necessary. Approaches like elementary mode analysis, flux balance analysis, deficiency analysis and chemical organization theory (OT) require only the stoichiometric structure of the reaction network for derivation of valuable information. In formalisms like Systems Biology Markup Language (SBML), however, information about the stoichiometric coefficients re...
Efficient CSL Model Checking Using Stratification
DEFF Research Database (Denmark)
Zhang, Lijun; Jansen, David N.; Nielson, Flemming; Hermanns, Holger
2012-01-01
For continuous-time Markov chains, the model-checking problem with respect to continuous-time stochastic logic (CSL) has been introduced and shown to be decidable by Aziz, Sanwal, Singhal and Brayton in 1996 [ 1, 2]. Their proof can be turned into an approximation algorithm with worse than...
Automata-Based CSL Model Checking
DEFF Research Database (Denmark)
Zhang, Lijun; Jansen, David N.; Nielson, Flemming; Hermanns, Holger
For continuous-time Markov chains, the model-checking problem with respect to continuous-time stochastic logic (CSL) has been introduced and shown to be decidable by Aziz, Sanwal, Singhal and Brayton in 1996. The presented decision procedure, however, has exponential complexity. In this paper, we...
Statistical Model Checking for Stochastic Hybrid Systems
DEFF Research Database (Denmark)
David, Alexandre; Du, Dehui; Larsen, Kim Guldstrand; Legay, Axel; Mikučionis, Marius; Poulsen, Danny Bøgsted; Sedwards, Sean
This paper presents novel extensions and applications of the UPPAAL-SMC model checker. The extensions allow for statistical model checking of stochastic hybrid systems. We show how our race-based stochastic semantics extends to networks of hybrid systems, and indicate the integration technique...... applied for implementing this semantics in the UPPAAL-SMC simulation engine. We report on two applications of the resulting tool-set coming from systems biology and energy aware buildings....
Three Notes on the Complexity of Model Checking Fixpoint Logic with Chop
DEFF Research Database (Denmark)
Lange, Martin
2007-01-01
This paper provides lower complexity bounds of deterministic exponential time for the combined, data and expression complexity of Fixpoint Logic with Chop. This matches the previously known upper bound showing that its model checking problem is EXPTIME-complete, even when the transition system or...
Howard, Y; Gravell, A; Ferreira, C; Augusto, J C
2011-01-01
Trace analysis can be a useful way to discover problems in a program under test. Rather than writing a special purpose trace analysis tool, this paper proposes that traces can usefully be analysed by checking them against a formal model using a standard model-checker or else an animator for executable specifications. These techniques are illustrated using a Travel Agent case study implemented in J2EE. We added trace beans to this code that write trace information to a database. The traces are then extracted and converted into a form suitable for analysis by Spin, a popular model-checker, and Pro-B, a model-checker and animator for the B notation. This illustrates the technique, and also the fact that such a system can have a variety of models, in different notations, that capture different features. These experiments have demonstrated that model-based trace-checking is feasible. Future work is focussed on scaling up the approach to larger systems by increasing the level of automation.
Model Checking over Paraconsistent Temporal Logic
Institute of Scientific and Technical Information of China (English)
CHEN Dong-huo; WANG Lin-zhang; CUI Jia-lin
2008-01-01
Classical logic cannot be used to effectively reason about concurrent systems with inconsistencies (inconsistencies often occur, especially in the early stage of the development, when large and complex concurrent systems are developed). In this paper, we propose the use of a guasi-classical temporal logic (QCTL) for supporting the verification of temporal properties of such systems even where the consistent model is not available. Our models are paraKripke structures ( extended standard Kripke structures), in which both a formula and its negation are satisfied in a same state, and properties to be verified are expressed by QCTL with paraKripke structures semantics. We introduce a novel notion of paraKripke models, which grasps the paraconsistent character of the entailment relation of QCTL. Furthermore, we explore the methodology of model checking over QCTL, and describe the detailed algorithm of implementing QCTL model checker. In the sequel, a simple example is presented, showing how to exploit the proposed model checking technique to verify the temporal properties of inconsistent concurrent systems.
Statistical Model Checking of Rich Models and Properties
DEFF Research Database (Denmark)
Poulsen, Danny Bøgsted
undecidability issues for the traditional model checking approaches. Statistical model checking has proven itself a valuable supplement to model checking and this thesis is concerned with extending this software validation technique to stochastic hybrid systems. The thesis consists of two parts: the first part...... motivates why existing model checking technology should be supplemented by new techniques. It also contains a brief introduction to probability theory and concepts covered by the six papers making up the second part. The first two papers are concerned with developing online monitoring techniques for...... systems. The fifth paper shows how stochastic hybrid automata are useful for modelling biological systems and the final paper is concerned with showing how statistical model checking is efficiently distributed. In parallel with developing the theory contained in the papers, a substantial part of this work...
SAT-Based Model Checking without Unrolling
Bradley, Aaron R.
A new form of SAT-based symbolic model checking is described. Instead of unrolling the transition relation, it incrementally generates clauses that are inductive relative to (and augment) stepwise approximate reachability information. In this way, the algorithm gradually refines the property, eventually producing either an inductive strengthening of the property or a counterexample trace. Our experimental studies show that induction is a powerful tool for generalizing the unreachability of given error states: it can refine away many states at once, and it is effective at focusing the proof search on aspects of the transition system relevant to the property. Furthermore, the incremental structure of the algorithm lends itself to a parallel implementation.
Distributed Parametric and Statistical Model Checking
Directory of Open Access Journals (Sweden)
Peter Bulychev
2011-10-01
Full Text Available Statistical Model Checking (SMC is a trade-off between testing and formal verification. The core idea of the approach is to conduct some simulations of the system and verify if they satisfy some given property. In this paper we show that SMC is easily parallelizable on a master/slaves architecture by introducing a series of algorithms that scale almost linearly with respect to the number of slave computers. Our approach has been implemented in the UPPAAL SMC toolset and applied on non-trivial case studies.
Workflow Fault Tree Generation Through Model Checking
DEFF Research Database (Denmark)
Herbert, Luke Thomas; Sharp, Robin
2014-01-01
probabilistic structure of the system being modelled. From these calculations, a comprehensive fault tree is generated. Further, we show that annotating the model with rewards (data) allows the expected mean values of reward structures to be calculated at points of failure....... with probabilistic non-deterministic branching. We present an algorithm that allows for exhaustive generation of possible error states that could arise in execution of the model, where the generated error states allow for both fail-stop behaviour and continued system execution. We employ stochastic...... model checking to calculate the probabilities of reaching each non-error system state. Each generated error state is assigned a variable indicating its individual probability of occurrence. Our method can determine the probability of combined faults occurring, while accounting for the basic...
Model Checking JAVA Programs Using Java Pathfinder
Havelund, Klaus; Pressburger, Thomas
2000-01-01
This paper describes a translator called JAVA PATHFINDER from JAVA to PROMELA, the "programming language" of the SPIN model checker. The purpose is to establish a framework for verification and debugging of JAVA programs based on model checking. This work should be seen in a broader attempt to make formal methods applicable "in the loop" of programming within NASA's areas such as space, aviation, and robotics. Our main goal is to create automated formal methods such that programmers themselves can apply these in their daily work (in the loop) without the need for specialists to manually reformulate a program into a different notation in order to analyze the program. This work is a continuation of an effort to formally verify, using SPIN, a multi-threaded operating system programmed in Lisp for the Deep-Space 1 spacecraft, and of previous work in applying existing model checkers and theorem provers to real applications.
Probabilistic Model--Checking of Quantum Protocols
Gay, S; Papanikolaou, N; Gay, Simon; Nagarajan, Rajagopal; Papanikolaou, Nikolaos
2005-01-01
We establish fundamental and general techniques for formal verification of quantum protocols. Quantum protocols are novel communication schemes involving the use of quantum-mechanical phenomena for representation, storage and transmission of data. As opposed to quantum computers, quantum communication systems can and have been implemented using present-day technology; therefore, the ability to model and analyse such systems rigorously is of primary importance. While current analyses of quantum protocols use a traditional mathematical approach and require considerable understanding of the underlying physics, we argue that automated verification techniques provide an elegant alternative. We demonstrate these techniques through the use of PRISM, a probabilistic model-checking tool. Our approach is conceptually simpler than existing proofs, and allows us to disambiguate protocol definitions and assess their properties. It also facilitates detailed analyses of actual implemented systems. We illustrate our techniqu...
Model Checking of Boolean Process Models
Schneider, Christoph; Wehler, Joachim
2011-01-01
In the field of Business Process Management formal models for the control flow of business processes have been designed since more than 15 years. Which methods are best suited to verify the bulk of these models? The first step is to select a formal language which fixes the semantics of the models. We adopt the language of Boolean systems as reference language for Boolean process models. Boolean systems form a simple subclass of coloured Petri nets. Their characteristics are low tokens to mode...
Probabilistic and hybrid model checking deployments for wireless sensor networks
International Nuclear Information System (INIS)
In the early stages of system development, model checking is a good practice for examining the WSNs (Wireless Sensor Networks). Model checking involves verifying a system's properties based on the system's finite state model. For varying applications like computers and wireless communication prior to expensive simulations, model checking has become a vital requirement in order to investigate the performance and reliability. In this paper for the first time, we are presenting probabilistic and hybrid model checking tools which are being implemented to analyse and verify the WSN applications and their examples. Here we are categorizing the model checking tools and presenting how they have been used for the investigation of various behaviours of WSN solutions. Consequently, this paper helps readers/researchers to choose the appropriate model checking tool and to get benefited in shape of validating their solutions. The paper has also highlighted the problems of existing model checking tools within WSN domain. (author)
Conformant Planning via Symbolic Model Checking
Cimatti, A; 10.1613/jair.774
2011-01-01
We tackle the problem of planning in nondeterministic domains, by presenting a new approach to conformant planning. Conformant planning is the problem of finding a sequence of actions that is guaranteed to achieve the goal despite the nondeterminism of the domain. Our approach is based on the representation of the planning domain as a finite state automaton. We use Symbolic Model Checking techniques, in particular Binary Decision Diagrams, to compactly represent and efficiently search the automaton. In this paper we make the following contributions. First, we present a general planning algorithm for conformant planning, which applies to fully nondeterministic domains, with uncertainty in the initial condition and in action effects. The algorithm is based on a breadth-first, backward search, and returns conformant plans of minimal length, if a solution to the planning problem exists, otherwise it terminates concluding that the problem admits no conformant solution. Second, we provide a symbolic representation ...
Using Model Checking to Validate AI Planner Domain Models
Penix, John; Pecheur, Charles; Havelund, Klaus
1999-01-01
This report describes an investigation into using model checking to assist validation of domain models for the HSTS planner. The planner models are specified using a qualitative temporal interval logic with quantitative duration constraints. We conducted several experiments to translate the domain modeling language into the SMV, Spin and Murphi model checkers. This allowed a direct comparison of how the different systems would support specific types of validation tasks. The preliminary results indicate that model checking is useful for finding faults in models that may not be easily identified by generating test plans.
Model Checking and Model-based Testing in the Railway Domain
DEFF Research Database (Denmark)
Haxthausen, Anne Elisabeth; Peleska, Jan
2015-01-01
This chapter describes some approaches and emerging trends for verification and model-based testing of railway control systems. We describe state-of-the-art methods and associated tools for verifying interlocking systems and their configuration data, using bounded model checking and k-induction. ......This chapter describes some approaches and emerging trends for verification and model-based testing of railway control systems. We describe state-of-the-art methods and associated tools for verifying interlocking systems and their configuration data, using bounded model checking and k......-induction. Using real-world models of novel Danish interlocking systems, it is exemplified how this method scales up and is suitable for industrial application. For verification of the integrated HW/SW system performing the interlocking control tasks, a modelbased hardware-in-the-loop testing approach is presented...
Analyzing Interoperability of Protocols Using Model Checking
Institute of Scientific and Technical Information of China (English)
WUPeng
2005-01-01
In practical terms, protocol interoperability testing is still laborious and error-prone with little effect, even for those products that have passed conformance testing. Deadlock and unsymmetrical data communication are familiar in interoperability testing, and it is always very hard to trace their causes. The previous work has not provided a coherent way to analyze why the interoperability was broken among protocol implementations under test. In this paper, an alternative approach is presented to analyzing these problems from a viewpoint of implementation structures. Sequential and concurrent structures are both representative implementation structures, especially in event-driven development model. Our research mainly discusses the influence of sequential and concurrent structures on interoperability, with two instructive conclusions: (a) a sequential structure may lead to deadlock; (b) a concurrent structure may lead to unsymmetrical data communication. Therefore, implementation structures carry weight on interoperability, which may not gain much attention before. To some extent, they are decisive on the result of interoperability testing. Moreover, a concurrent structure with a sound task-scheduling strategy may contribute to the interoperability of a protocol implementation. Herein model checking technique is introduced into interoperability analysis for the first time. As the paper shows, it is an effective way to validate developers' selections on implementation structures or strategies.
Checking for normality in linear mixed models
Institute of Scientific and Technical Information of China (English)
WU Ping; ZHU LiXing; FANG Yun
2012-01-01
Linear mixed models are popularly used to fit continuous longitudinal data,and the random effects are commonly assumed to have normal distribution.However,this assumption needs to be tested so that further analysis can be proceeded well.In this paper,we consider the Baringhaus-Henze-Epps-Pulley (BHEP) tests,which are based on an empirical characteristic function.Differing from their case,we consider the normality checking for the random effects which are unobservable and the test should be based on their predictors.The test is consistent against global alternatives,and is sensitive to the local alternatives converging to the null at a certain rate arbitrarily close to 1/(√)n where n is sample size.Furthermore,to overcome the problem that the limiting null distribution of the test is not tractable,we suggest a new method:use a conditional Monte Carlo test (CMCT) to approximate the null distribution,and then to simulate p-values.The test is compared with existing methods,the power is examined,and several examples are applied to illustrate the usefulness of our test in the analysis of longitudinal data.
Modelling Chinese Smart Grid : A stochastic model checking case study
Energy Technology Data Exchange (ETDEWEB)
Yuksel, E.; Nielson, H.R.; Nielson, F. (Technical Univ. of Denmark. DTU Informatics, Kgs. Lyngby (Denmark)); Zhu, H. (East China Normal Univ. (China)); Huang, H. (Wuxi SensingNet Industrialization Research Institute (China))
2012-07-01
In this document, we consider a specific Chinese Smart Grid implementation and try to address the verification problem for certain quantitative properties including performance and battery consumption. We employ stochastic model checking approach and present our modelling and analysis study using PRISM model checker. (Author)
Verifying Multi-Agent Systems via Unbounded Model Checking
Kacprzak, M.; Lomuscio, A.; Lasica, T.; Penczek, W.; Szreter, M.
2004-01-01
We present an approach to the problem of verification of epistemic properties in multi-agent systems by means of symbolic model checking. In particular, it is shown how to extend the technique of unbounded model checking from a purely temporal setting to a temporal-epistemic one. In order to achieve this, we base our discussion on interpreted systems semantics, a popular semantics used in multi-agent systems literature. We give details of the technique and show how it can be applied to the well known train, gate and controller problem. Keywords: model checking, unbounded model checking, multi-agent systems
A Method for Model Checking Feature Interactions
DEFF Research Database (Denmark)
Pedersen, Thomas; Le Guilly, Thibaut; Ravn, Anders Peter; Skou, Arne Joachim
This paper presents a method to check for feature interactions in a system assembled from independently developed concurrent processes as found in many reactive systems. The method combines and refines existing definitions and adds a set of activities. The activities describe how to populate the ...
Modeling Environment for Component Model Checking from Hierarchical Architecture
Czech Academy of Sciences Publication Activity Database
Pařízek, P.; Plášil, František
2007-01-01
Roč. 182, - (2007), s. 139-153. ISSN 1571-0661 R&D Projects: GA ČR GA201/06/0770 Institutional research plan: CEZ:AV0Z10300504 Keywords : software components * behavior protocols * environment model checking * hierarchical component architecture Subject RIV: JC - Computer Hardware ; Software
Implementing Model-Check for Employee and Management Satisfaction
Jones, Corey; LaPha, Steven
2013-01-01
This presentation will discuss methods to which ModelCheck can be implemented to not only improve model quality, but also satisfy both employees and management through different sets of quality checks. This approach allows a standard set of modeling practices to be upheld throughout a company, with minimal interaction required by the end user. The presenter will demonstrate how to create multiple ModelCheck standards, preventing users from evading the system, and how it can improve the quality of drawings and models.
Efficient Checking of Individual Rewards Properties in Markov Population Models
Bortolussi, Luca; Hillston, Jane
2015-01-01
In recent years fluid approaches to the analysis of Markov populations models have been demonstrated to have great pragmatic value. Initially developed to estimate the behaviour of the system in terms of the expected values of population counts, the fluid approach has subsequently been extended to more sophisticated interrogations of models through its embedding within model checking procedures. In this paper we extend recent work on checking CSL properties of individual agents within a Marko...
Dynamic State Space Partitioning for External Memory Model Checking
DEFF Research Database (Denmark)
Evangelista, Sami; Kristensen, Lars Michael
2009-01-01
We describe a dynamic partitioning scheme usable by model checking techniques that divide the state space into partitions, such as most external memory and distributed model checking algorithms. The goal of the scheme is to reduce the number of transitions that link states belonging to different...... partitions, and thereby limit the amount of disk access and network communication. We report on several experiments made with our verification platform ASAP that implements the dynamic partitioning scheme proposed in this paper....
Model checking biological systems described using ambient calculus
DEFF Research Database (Denmark)
Mardare, Radu Iulian; Priami, Corrado; Qualia, Paola; Vagin, Oleksander
2005-01-01
Model checking biological systems described using ambient calculus. In Proc. of the second International Workshop on Computational Methods in Systems Biology (CMSB04), Lecture Notes in Bioinformatics 3082:85-103, Springer, 2005.......Model checking biological systems described using ambient calculus. In Proc. of the second International Workshop on Computational Methods in Systems Biology (CMSB04), Lecture Notes in Bioinformatics 3082:85-103, Springer, 2005....
Model Checking-Based Testing of Web Applications
Institute of Scientific and Technical Information of China (English)
ZENG Hongwei; MIAO Huaikou
2007-01-01
A formal model representing the navigation behavior of a Web application as the Kripke structure is proposed and an approach that applies model checking to test case generation is presented. The Object Relation Diagram as the object model is employed to describe the object structure of a Web application design and can be translated into the behavior model. A key problem of model checking-based test generation for a Web application is how to construct a set of trap properties that intend to cause the violations of model checking against the behavior model and output of counterexamples used to construct the test sequences.We give an algorithm that derives trap properties from the object model with respect to node and edge coverage criteria.
Learning Markov Decision Processes for Model Checking
Directory of Open Access Journals (Sweden)
Hua Mao
2012-12-01
Full Text Available Constructing an accurate system model for formal model verification can be both resource demanding and time-consuming. To alleviate this shortcoming, algorithms have been proposed for automatically learning system models based on observed system behaviors. In this paper we extend the algorithm on learning probabilistic automata to reactive systems, where the observed system behavior is in the form of alternating sequences of inputs and outputs. We propose an algorithm for automatically learning a deterministic labeled Markov decision process model from the observed behavior of a reactive system. The proposed learning algorithm is adapted from algorithms for learning deterministic probabilistic finite automata, and extended to include both probabilistic and nondeterministic transitions. The algorithm is empirically analyzed and evaluated by learning system models of slot machines. The evaluation is performed by analyzing the probabilistic linear temporal logic properties of the system as well as by analyzing the schedulers, in particular the optimal schedulers, induced by the learned models.
Learning Markov Decision Processes for Model Checking
DEFF Research Database (Denmark)
Mao, Hua; Chen, Yingke; Jaeger, Manfred;
2012-01-01
Constructing an accurate system model for formal model verification can be both resource demanding and time-consuming. To alleviate this shortcoming, algorithms have been proposed for automatically learning system models based on observed system behaviors. In this paper we extend the algorithm on...... learning probabilistic automata to reactive systems, where the observed system behavior is in the form of alternating sequences of inputs and outputs. We propose an algorithm for automatically learning a deterministic labeled Markov decision process model from the observed behavior of a reactive system....... The proposed learning algorithm is adapted from algorithms for learning deterministic probabilistic finite automata, and extended to include both probabilistic and nondeterministic transitions. The algorithm is empirically analyzed and evaluated by learning system models of slot machines. The...
Model checking Branching-Time Properties of Multi-Pushdown Systems is Hard
Atig, Mohamed Faouzi; Kumar, K Narayan; Saivasan, Prakash
2012-01-01
We address the model checking problem for shared memory concurrent programs modeled as multi-pushdown systems. We consider here boolean programs with a finite number of threads and recursive procedures. It is well-known that the model checking problem is undecidable for this class of programs. In this paper, we investigate the decidability and the complexity of this problem under the assumption of bounded context-switching defined by Qadeer and Rehof, and of phase-boundedness proposed by La Torre et al. On the model checking of such systems against temporal logics and in particular branching time logics such as the modal $\\mu$-calculus or CTL has received little attention. It is known that parity games, which are closely related to the modal $\\mu$-calculus, are decidable for the class of bounded-phase systems (and hence for bounded-context switching as well), but with non-elementary complexity (Seth). A natural question is whether this high complexity is inevitable and what are the ways to get around it. This...
Linear Parametric Model Checking of Timed Automata
DEFF Research Database (Denmark)
Hune, Tohmas Seidelin; Romijn, Judi; Stoelinga, Mariëlle; Vaandrager, Frits W.
We present an extension of the model checker Uppaal capable of synthesize linear parameter constraints for the correctness of parametric timed automata. The symbolic representation of the (parametric) state-space is shown to be correct. A second contribution of this paper is the identication of a...
Abstraction and Model Checking in the PEPA Plug-in for Eclipse
DEFF Research Database (Denmark)
Smith, Michael James Andrew
2010-01-01
The stochastic process algebra PEPA is a widely used language for performance modelling, and a large part of its success is due to the rich tool support that is available. As a compositional Markovian formalism, however, it suffers from the state space explosion problem, where even small models can...... lead to very large Markov chains. One way of analysing such models is to use abstraction - constructing a smaller model that bounds the properties of the original. We present an extension to the PEPA plug-in for Eclipse that enables abstracting and model checking of PEPA models. This implements two new...
Diagnostic checking for conditional heteroscedasticity models
Institute of Scientific and Technical Information of China (English)
无
2010-01-01
We suggest the score type tests for goodness-of-fit of conditional heteroscedasticity models in both univariate and multivariate time series.The tests can detect the alternatives converging to the null at a parametric rate.Weight functions are involved in the construction of the tests,which provides us with the flexibility to choose scores,especially under directional alternatives,for enhancing power performance.Furthermore,when the alternatives are not directional,we construct asymptotically distribution-free maximin tests for a large class of alternatives.A possibility to construct score-based omnibus tests is discussed when the alternative is saturated.The power performance is also investigated.A simulation study is carried out and a real data is analyzed.
Conductivity bounds in probe brane models
Ikeda, Tatsuhiko N; Nakai, Yuichiro
2016-01-01
We discuss upper and lower bounds on the electrical conductivity of finite temperature strongly coupled quantum field theories, holographically dual to probe brane models, within linear response. In a probe limit where disorder is introduced entirely through an inhomogeneous background charge density, we find simple lower and upper bounds on the electrical conductivity in arbitrary dimensions. In field theories in two spatial dimensions, we show that both bounds persist even when disorder is included in the bulk metric. We discuss the challenges with finding sharp lower bounds on conductivity in three or more spatial dimensions when the metric is inhomogeneous.
Towards Model Checking a Spi-Calculus Dialect
Gnesi, S.; Latella, D.; Lenzini, G.
2002-01-01
We present a model checking framework for a spi-calculus dialect which uses a linear time temporal logic for expressing security properties. We have provided our spi-calculus dialect, called SPID, with a semantics based on labeled transition systems (LTS), where the intruder is modeled in the Dolev-
Using Model Checking for Analyzing Distributed Power Control Problems
DEFF Research Database (Denmark)
Brihaye, Thomas; Jungers, Marc; Lasaulce, Samson; Markey, Nicolas; Oreiby, Ghassan
2010-01-01
Model checking (MC) is a formal verification technique which has been known and still knows a resounding success in the computer science community. Realizing that the distributed power control ( PC) problem can be modeled by a timed game between a given transmitter and its environment, the authors...
Model checking conditional CSL for continuous-time Markov chains
DEFF Research Database (Denmark)
Gao, Yang; Xu, Ming; Zhan, Naijun;
2013-01-01
probabilistic operator. CCSL allows us to express a richer class of properties for CTMCs. Based on a parameterized product obtained from the CTMC and an automaton extracted from a given CCSL formula, we propose an approximate model checking algorithm and analyse its complexity....
An Extended Ontology Model and Ontology Checking Based on Description Logics
Institute of Scientific and Technical Information of China (English)
王洪伟; 蒋馥; 吴家春
2004-01-01
Ontology is defined as an explicit specification of a conceptualization. In this paper, an extended ontology model was constructed using description logics, which is a 5-tuples including term set, individual set, term definition set, instantiation assertion set and term restriction set. Based on the extended model, the issue on ontology checking was studied with the conclusion that the four kinds of term checking, including term satisfiability checking, term subsumption checking, term equivalence checking and term disjointness checking, can be reduced to the satisfiability checking, and satisfiability checking can be transformed into instantiation consistence checking.
Mixed Portmanteau Test for Diagnostic Checking of Time Series Models
Directory of Open Access Journals (Sweden)
Sohail Chand
2014-01-01
Full Text Available Model criticism is an important stage of model building and thus goodness of fit tests provides a set of tools for diagnostic checking of the fitted model. Several tests are suggested in literature for diagnostic checking. These tests use autocorrelation or partial autocorrelation in the residuals to criticize the adequacy of fitted model. The main idea underlying these portmanteau tests is to identify if there is any dependence structure which is yet unexplained by the fitted model. In this paper, we suggest mixed portmanteau tests based on autocorrelation and partial autocorrelation functions of the residuals. We derived the asymptotic distribution of the mixture test and studied its size and power using Monte Carlo simulations.
Model-Checking Real-Time Properties of an Aircraft Landing Gear System Using Fiacre
Berthomieu, Bernard; Dal Zilio, Silvano; Fronc, Lukasz
2014-01-01
International audience We describe our experience with modeling the landing gear system of an aircraft using the formal specification language Fiacre. Our model takes into account the behavior and timing properties of both the physical parts and the control software of this system. We use this formal model to check safety and real-time properties on the system but also to find a safe bound on the maximal time needed for all gears to be down and locked (assuming the absence of failures). Ou...
Logic Model Checking of Unintended Acceleration Claims in Toyota Vehicles
Gamble, Ed
2012-01-01
Part of the US Department of Transportation investigation of Toyota sudden unintended acceleration (SUA) involved analysis of the throttle control software, JPL Laboratory for Reliable Software applied several techniques including static analysis and logic model checking, to the software; A handful of logic models were build, Some weaknesses were identified; however, no cause for SUA was found; The full NASA report includes numerous other analyses
Symbolic Model Checking and Analysis for E-Commerce Protocol
Institute of Scientific and Technical Information of China (English)
WEN Jing-Hua; ZHANG Mei; LI Xiang
2005-01-01
A new approach is proposed for analyzing non-repudiation and fairness of e-commerce protocols. The authentication e-mail protocol CMP1 is modeled as finite state machine and analyzed in two vital aspects - non-repudiation and fairness using SMV. As a result, the CMP1 protocol is not fair and we have improved it. This result shows that it is effective to analyze and check the new features of e-commerce protocols using SMV model checker
Schedulability of Herschel revisited using statistical model checking
DEFF Research Database (Denmark)
David, Alexandre; Larsen, Kim Guldstrand; Legay, Axel;
2015-01-01
Schedulability analysis is a main concern for several embedded applications due to their safety-critical nature. The classical method of response time analysis provides an efficient technique used in industrial practice. However, the method is based on conservative assumptions related to execution...... and blocking times of tasks. Consequently, the method may falsely declare deadline violations that will never occur during execution. This paper is a continuation of previous work of the authors in applying extended timed automata model checking (using the tool UPPAAL) to obtain more exact...... schedulability analysis, here in the presence of non-deterministic computation times of tasks given by intervals [BCET,WCET]. Computation intervals with preemptive schedulers make the schedulability analysis of the resulting task model undecidable. Our contribution is to propose a combination of model checking...
Analysis of DIRAC's behavior using model checking with process algebra
Remenska, Daniela; Willemse, Tim; Bal, Henri; Verstoep, Kees; Fokkink, Wan; Charpentier, Philippe; Diaz, Ricardo Graciani; Lanciotti, Elisa; Roiser, Stefan; Ciba, Krzysztof
2012-01-01
DIRAC is the grid solution developed to support LHCb production activities as well as user data analysis. It consists of distributed services and agents delivering the workload to the grid resources. Services maintain database back-ends to store dynamic state information of entities such as jobs, queues, staging requests, etc. Agents use polling to check and possibly react to changes in the system state. Each agent's logic is relatively simple, the main complexity lies in their cooperation. Agents run concurrently, and collaborate using the databases as shared memory. The databases can be accessed directly by the agents if running locally or through a DIRAC service interface if necessary. This shared-memory model causes entities to occasionally get into inconsistent states. Tracing and fixing such problems becomes formidable due to the inherent parallelism present. We propose more rigorous methods to cope with this. Model checking is one such technique for analysis of an abstract model of a system. Unlike con...
Stochastic Semantics and Statistical Model Checking for Networks of Priced Timed Automata
David, Alexandre; Legay, Axel; Mikučionis, Marius; Poulsen, Danny Bøgsted; van Vliet, Jonas; Wang, Zheng
2011-01-01
This paper offers a natural stochastic semantics of Networks of Priced Timed Automata (NPTA) based on races between components. The semantics provides the basis for satisfaction of probabilistic Weighted CTL properties (PWCTL), conservatively extending the classical satisfaction of timed automata with respect to TCTL. In particular the extension allows for hard real-time properties of timed automata expressible in TCTL to be refined by performance properties, e.g. in terms of probabilistic guarantees of time- and cost-bounded properties. A second contribution of the paper is the application of Statistical Model Checking (SMC) to efficiently estimate the correctness of non-nested PWCTL model checking problems with a desired level of confidence, based on a number of independent runs of the NPTA. In addition to applying classical SMC algorithms, we also offer an extension that allows to efficiently compare performance properties of NPTAs in a parametric setting. The third contribution is an efficient tool implem...
Detecting feature interactions in Web services with model checking techniques
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
As a platform-independent software system, a Web service is designed to offer interoperability among diverse and heterogeneous applications.With the introduction of service composition in the Web service creation, various message interactions among the atomic services result in a problem resembling the feature interaction problem in the telecommunication area.This article defines the problem as feature interaction in Web services and proposes a model checking-based detection method.In the method, the Web service description is translated to the Promela language - the input language of the model checker simple promela interpreter (SPIN), and the specific properties, expressed as linear temporal logic (LTL) formulas, are formulated according to our classification of feature interaction.Then, SPIN is used to check these specific properties to detect the feature interaction in Web services.
Model Checking Processes Specified In Join-Calculus Algebra
Directory of Open Access Journals (Sweden)
Sławomir Piotr Maludziński
2014-01-01
Full Text Available This article presents a model checking tool used to verify concurrent systems specified in join-calculus algebra. The temporal properties of systems under verification are expressed in CTL logic. Join-calculus algebra with its operational semantics defined by the chemical abstract machine serves as the basic method for the specification of concurrent systems and their synchronization mechanisms, and allows the examination of more complex systems.
Model Checking Processes Specified In Join-Calculus Algebra
Sławomir Piotr Maludziński; Grzegorz Dobrowolski
2014-01-01
This article presents a model checking tool used to verify concurrent systems specified in join-calculus algebra. The temporal properties of systems under verification are expressed in CTL logic. Join-calculus algebra with its operational semantics defined by the chemical abstract machine serves as the basic method for the specification of concurrent systems and their synchronization mechanisms, and allows the examination of more complex systems.
A Graphical μ-Calculus and Local Model Checking
Institute of Scientific and Technical Information of China (English)
林惠民
2002-01-01
A graphical notation for the propositionalμ-calculus, called modal graphs, ispresented. It is shown that both the textual and equational presentations of theμ-calculus canbe translated into modal graphs. A model checking algorithm based on such graphs is proposed.The algorithm is truly local in the sense that it only generates the parts of the underlyingsearch space which are necessary for the computation of the final result. The correctness of thealgorithm is proven and its complexity analysed.
Model Checking for Licensing Support in the Finnish Nuclear Industry
Energy Technology Data Exchange (ETDEWEB)
Antti, Pakonen; Janne, Valkonen [VTT Technical Research, VTT (Finland); Sami, Matinaho; Markus, Hartikainen [Protum Power and Heat, Fortum (Finland)
2014-08-15
This paper examines how model checking can be used to support the qualification of digital I and C software in nuclear power plants, in a way that is consistent with regulatory demands specifically, the common position of seven European nuclear regulators and authorised technical support organisations. As a practical example, we discuss the third-party review service provided by VTT for the power company Fortum in the I and C renewal project of the Loviisa plant in southern Finland.
Parallel State Space Construction for Model-Checking
Garavel, Hubert; Mateescu, Radu; Smarandache, Irina
2001-01-01
The verification of concurrent finite-state systems by model-checking often requires to generate (a large part of) the state space of the system under analysis. Because of the state explosion problem, this may be a resource-consuming operation, both in terms of memory and CPU time. In this report, we aim at improving the performances of state space construction by using parallelization techniques. We present parallel algorithms for constructing state spaces (or Labeled Transition Systems) on ...
Model-checking techniques based on cumulative residuals.
Lin, D Y; Wei, L J; Ying, Z
2002-03-01
Residuals have long been used for graphical and numerical examinations of the adequacy of regression models. Conventional residual analysis based on the plots of raw residuals or their smoothed curves is highly subjective, whereas most numerical goodness-of-fit tests provide little information about the nature of model misspecification. In this paper, we develop objective and informative model-checking techniques by taking the cumulative sums of residuals over certain coordinates (e.g., covariates or fitted values) or by considering some related aggregates of residuals, such as moving sums and moving averages. For a variety of statistical models and data structures, including generalized linear models with independent or dependent observations, the distributions of these stochastic processes tinder the assumed model can be approximated by the distributions of certain zero-mean Gaussian processes whose realizations can be easily generated by computer simulation. Each observed process can then be compared, both graphically and numerically, with a number of realizations from the Gaussian process. Such comparisons enable one to assess objectively whether a trend seen in a residual plot reflects model misspecification or natural variation. The proposed techniques are particularly useful in checking the functional form of a covariate and the link function. Illustrations with several medical studies are provided. PMID:11890304
Model-Checking Linear-Time Properties of Quantum Systems
Ying, Mingsheng; Yu, Nengkun; Feng, Yuan
2011-01-01
We define a formal framework for reasoning about linear-time properties of quantum systems in which quantum automata are employed in the modeling of systems and certain closed subspaces of state (Hilbert) spaces are used as the atomic propositions about the behavior of systems. We provide an algorithm for verifying invariants of quantum automata. Then automata-based model-checking technique is generalized for the verification of safety properties recognizable by reversible automata and omega-properties recognizable by reversible Buechi automata.
Model Checking Data Consistency for Cache Coherence Protocols
Institute of Scientific and Technical Information of China (English)
Hong Pan; Hui-Min Lin; Yi Lv
2006-01-01
A method for automatic verification of cache coherence protocols is presented, in which cache coherence protocols are modeled as concurrent value-passing processes, and control and data consistency requirement are described as formulas in first-orderμ-calculus. A model checker is employed to check if the protocol under investigation satisfies the required properties. Using this method a data consistency error has been revealed in a well-known cache coherence protocol.The error has been corrected, and the revised protocol has been shown free from data consistency error for any data domain size, by appealing to data independence technique.
Applying Model Checking to Industrial-Sized PLC Programs
AUTHOR|(CDS)2079190; Darvas, Daniel; Blanco Vinuela, Enrique; Tournier, Jean-Charles; Bliudze, Simon; Blech, Jan Olaf; Gonzalez Suarez, Victor M
2015-01-01
Programmable logic controllers (PLCs) are embedded computers widely used in industrial control systems. Ensuring that a PLC software complies with its specification is a challenging task. Formal verification has become a recommended practice to ensure the correctness of safety-critical software but is still underused in industry due to the complexity of building and managing formal models of real applications. In this paper, we propose a general methodology to perform automated model checking of complex properties expressed in temporal logics (\\eg CTL, LTL) on PLC programs. This methodology is based on an intermediate model (IM), meant to transform PLC programs written in various standard languages (ST, SFC, etc.) to different modeling languages of verification tools. We present the syntax and semantics of the IM and the transformation rules of the ST and SFC languages to the nuXmv model checker passing through the intermediate model. Finally, two real cases studies of \\CERN PLC programs, written mainly in th...
SoS contract verification using statistical model checking
Directory of Open Access Journals (Sweden)
Alessandro Mignogna
2013-11-01
Full Text Available Exhaustive formal verification for systems of systems (SoS is impractical and cannot be applied on a large scale. In this paper we propose to use statistical model checking for efficient verification of SoS. We address three relevant aspects for systems of systems: 1 the model of the SoS, which includes stochastic aspects; 2 the formalization of the SoS requirements in the form of contracts; 3 the tool-chain to support statistical model checking for SoS. We adapt the SMC technique for application to heterogeneous SoS. We extend the UPDM/SysML specification language to express the SoS requirements that the implemented strategies over the SoS must satisfy. The requirements are specified with a new contract language specifically designed for SoS, targeting a high-level English- pattern language, but relying on an accurate semantics given by the standard temporal logics. The contracts are verified against the UPDM/SysML specification using the Statistical Model Checker (SMC PLASMA combined with the simulation engine DESYRE, which integrates heterogeneous behavioral models through the functional mock-up interface (FMI standard. The tool-chain allows computing an estimation of the satisfiability of the contracts by the SoS. The results help the system architect to trade-off different solutions to guide the evolution of the SoS.
Stochastic Model Checking of the Stochastic Quality Calculus
DEFF Research Database (Denmark)
Nielson, Flemming; Nielson, Hanne Riis; Zeng, Kebin
2015-01-01
The Quality Calculus uses quality binders for input to express strategies for continuing the computation even when the desired input has not been received. The Stochastic Quality Calculus adds generally distributed delays for output actions and real-time constraints on the quality binders for inp...... based on stochastic model checking and we compute closed form solutions for a number of interesting scenarios. The analyses are applied to the design of an intelligent smart electrical meter of the kind to be installed in European households by 2020....
Symbolic Game Semantics for Model Checking Program Families
DEFF Research Database (Denmark)
Dimovski, Aleksandar
this paper, we propose an efficient game semantics based approach for verifying open program families, i.e. program families with free (undefined) identifiers. We use symbolic representation of algorithmic game semantics, where concrete values are replaced with symbolic ones. In this way, we can...... compactly represent program families with infinite integers as so-called (finite-state) featured symbolic automata. Specifically designed model checking algorithms are then employed to verify safety of all programs from a family at once and pinpoint those programs that are unsafe (respectively, safe). We...
Model Checking Degrees of Belief in a System of Agents
Raimondi, Franco; Primero, Giuseppe; Rungta, Neha
2014-01-01
Reasoning about degrees of belief has been investigated in the past by a number of authors and has a number of practical applications in real life. In this paper we present a unified framework to model and verify degrees of belief in a system of agents. In particular, we describe an extension of the temporal-epistemic logic CTLK and we introduce a semantics based on interpreted systems for this extension. In this way, degrees of beliefs do not need to be provided externally, but can be derived automatically from the possible executions of the system, thereby providing a computationally grounded formalism. We leverage the semantics to (a) construct a model checking algorithm, (b) investigate its complexity, (c) provide a Java implementation of the model checking algorithm, and (d) evaluate our approach using the standard benchmark of the dining cryptographers. Finally, we provide a detailed case study: using our framework and our implementation, we assess and verify the situational awareness of the pilot of Air France 447 flying in off-nominal conditions.
Generalized Symbolic Execution for Model Checking and Testing
Khurshid, Sarfraz; Pasareanu, Corina; Visser, Willem; Kofmeyer, David (Technical Monitor)
2003-01-01
Modern software systems, which often are concurrent and manipulate complex data structures must be extremely reliable. We present a novel framework based on symbolic execution, for automated checking of such systems. We provide a two-fold generalization of traditional symbolic execution based approaches: one, we define a program instrumentation, which enables standard model checkers to perform symbolic execution; two, we give a novel symbolic execution algorithm that handles dynamically allocated structures (e.g., lists and trees), method preconditions (e.g., acyclicity of lists), data (e.g., integers and strings) and concurrency. The program instrumentation enables a model checker to automatically explore program heap configurations (using a systematic treatment of aliasing) and manipulate logical formulae on program data values (using a decision procedure). We illustrate two applications of our framework: checking correctness of multi-threaded programs that take inputs from unbounded domains with complex structure and generation of non-isomorphic test inputs that satisfy a testing criterion. Our implementation for Java uses the Java PathFinder model checker.
Model checking as an aid to procedure design
International Nuclear Information System (INIS)
The OECD Halden Reactor Project has been actively working on computer assisted operating procedures for many years. The objective of the research has been to provide computerised assistance for procedure design, verification and validation, implementation and maintenance. For the verification purpose, the application of formal methods has been considered in several reports. The recent formal verification activity conducted at the Halden Project is based on using model checking to the verification of procedures. This report presents verification approaches based on different model checking techniques and tools for the formalization and verification of operating procedures. Possible problems and relative merits of the different approaches are discussed. A case study of one of the approaches is presented to show the practical application of formal verification. Application of formal verification in the traditional procedure design process can reduce the human resources involved in reviews and simulations, and hence reduce the cost of verification and validation. A discussion of the integration of the formal verification with the traditional procedure design process is given at the end of this report. (Author)
Reasoning About Strategies: On the Model-Checking Problem
Mogavero, Fabio; Perelli, Giuseppe; Vardi, Moshe Y
2011-01-01
In open systems verification, to formally check for reliability, one needs an appropriate formalism to model the interaction between agents and express the correctness of the system no matter how the environment behaves. An important contribution in this context is given by modal logics for strategic ability, in the setting of multi-agent games, such as ATL, ATL*, and the like. Recently, Chatterjee, Henzinger, and Piterman introduced Strategy Logic (CHP-SL), with the aim of getting a powerful framework for reasoning explicitly about strategies. CHP-SL is obtained by using first-order quantifications over strategies and it has been investigated in the setting of two-agents turned-based games, where a non-elementary model-checking algorithm has been provided. While CHP-SL is a very expressive logic, we claim that it does not fully capture the strategic aspects of multi-agent systems. In this paper, we introduce and study a more general strategy logic, denoted SL, for reasoning about strategies in multi-agent co...
Using Model Checking for Analyzing Distributed Power Control Problems
Directory of Open Access Journals (Sweden)
Thomas Brihaye
2010-01-01
Full Text Available Model checking (MC is a formal verification technique which has been known and still knows a resounding success in the computer science community. Realizing that the distributed power control (PC problem can be modeled by a timed game between a given transmitter and its environment, the authors wanted to know whether this approach can be applied to distributed PC. It turns out that it can be applied successfully and allows one to analyze realistic scenarios including the case of discrete transmit powers and games with incomplete information. The proposed methodology is as follows. We state some objectives a transmitter-receiver pair would like to reach. The network is modeled by a game where transmitters are considered as timed automata interacting with each other. The objectives are then translated into timed alternating-time temporal logic formulae and MC is exploited to know whether the desired properties are verified and determine a winning strategy.
Model-checking dense-time Duration Calculus
DEFF Research Database (Denmark)
Fränzle, Martin
2004-01-01
Since the seminal work of Zhou Chaochen, M. R. Hansen, and P. Sestoft on decidability of dense-time Duration Calculus [Zhou, Hansen, Sestoft, 1993] it is well-known that decidable fragments of Duration Calculus can only be obtained through withdrawal of much of the interesting vocabulary of this...... logic. While this was formerly taken as an indication that key-press verification of implementations with respect to elaborate Duration Calculus specifications were also impossible, we show that the model property is well decidable for realistic designs which feature natural constraints on their...... suitably sparser model classes we obtain model-checking procedures for rich subsets of Duration Calculus. Together with undecidability results also obtained, this sheds light upon the exact borderline between decidability and undecidability of Duration Calculi and related logics....
Methods to model-check parallel systems software.
Energy Technology Data Exchange (ETDEWEB)
Matlin, O. S.; McCune, W.; Lusk, E.
2003-12-15
We report on an effort to develop methodologies for formal verification of parts of the Multi-Purpose Daemon (MPD) parallel process management system. MPD is a distributed collection of communicating processes. While the individual components of the collection execute simple algorithms, their interaction leads to unexpected errors that are difficult to uncover by conventional means. Two verification approaches are discussed here: the standard model checking approach using the software model checker SPIN and the nonstandard use of a general-purpose first-order resolution-style theorem prover OTTER to conduct the traditional state space exploration. We compare modeling methodology and analyze performance and scalability of the two methods with respect to verification of MPD.
Analysis of DIRAC's behavior using model checking with process algebra
International Nuclear Information System (INIS)
DIRAC is the grid solution developed to support LHCb production activities as well as user data analysis. It consists of distributed services and agents delivering the workload to the grid resources. Services maintain database back-ends to store dynamic state information of entities such as jobs, queues, staging requests, etc. Agents use polling to check and possibly react to changes in the system state. Each agent's logic is relatively simple; the main complexity lies in their cooperation. Agents run concurrently, and collaborate using the databases as shared memory. The databases can be accessed directly by the agents if running locally or through a DIRAC service interface if necessary. This shared-memory model causes entities to occasionally get into inconsistent states. Tracing and fixing such problems becomes formidable due to the inherent parallelism present. We propose more rigorous methods to cope with this. Model checking is one such technique for analysis of an abstract model of a system. Unlike conventional testing, it allows full control over the parallel processes execution, and supports exhaustive state-space exploration. We used the mCRL2 language and toolset to model the behavior of two related DIRAC subsystems: the workload and storage management system. Based on process algebra, mCRL2 allows defining custom data types as well as functions over these. This makes it suitable for modeling the data manipulations made by DIRAC's agents. By visualizing the state space and replaying scenarios with the toolkit's simulator, we have detected race-conditions and deadlocks in these systems, which, in several cases, were confirmed to occur in the reality. Several properties of interest were formulated and verified with the tool. Our future direction is automating the translation from DIRAC to a formal model.
Analysis of DIRAC's behavior using model checking with process algebra
Remenska, Daniela; Templon, Jeff; Willemse, Tim; Bal, Henri; Verstoep, Kees; Fokkink, Wan; Charpentier, Philippe; Graciani Diaz, Ricardo; Lanciotti, Elisa; Roiser, Stefan; Ciba, Krzysztof
2012-12-01
DIRAC is the grid solution developed to support LHCb production activities as well as user data analysis. It consists of distributed services and agents delivering the workload to the grid resources. Services maintain database back-ends to store dynamic state information of entities such as jobs, queues, staging requests, etc. Agents use polling to check and possibly react to changes in the system state. Each agent's logic is relatively simple; the main complexity lies in their cooperation. Agents run concurrently, and collaborate using the databases as shared memory. The databases can be accessed directly by the agents if running locally or through a DIRAC service interface if necessary. This shared-memory model causes entities to occasionally get into inconsistent states. Tracing and fixing such problems becomes formidable due to the inherent parallelism present. We propose more rigorous methods to cope with this. Model checking is one such technique for analysis of an abstract model of a system. Unlike conventional testing, it allows full control over the parallel processes execution, and supports exhaustive state-space exploration. We used the mCRL2 language and toolset to model the behavior of two related DIRAC subsystems: the workload and storage management system. Based on process algebra, mCRL2 allows defining custom data types as well as functions over these. This makes it suitable for modeling the data manipulations made by DIRAC's agents. By visualizing the state space and replaying scenarios with the toolkit's simulator, we have detected race-conditions and deadlocks in these systems, which, in several cases, were confirmed to occur in the reality. Several properties of interest were formulated and verified with the tool. Our future direction is automating the translation from DIRAC to a formal model.
Malekpour, Mahyar R.
2007-01-01
This report presents the mechanical verification of a simplified model of a rapid Byzantine-fault-tolerant self-stabilizing protocol for distributed clock synchronization systems. This protocol does not rely on any assumptions about the initial state of the system. This protocol tolerates bursts of transient failures, and deterministically converges within a time bound that is a linear function of the self-stabilization period. A simplified model of the protocol is verified using the Symbolic Model Verifier (SMV) [SMV]. The system under study consists of 4 nodes, where at most one of the nodes is assumed to be Byzantine faulty. The model checking effort is focused on verifying correctness of the simplified model of the protocol in the presence of a permanent Byzantine fault as well as confirmation of claims of determinism and linear convergence with respect to the self-stabilization period. Although model checking results of the simplified model of the protocol confirm the theoretical predictions, these results do not necessarily confirm that the protocol solves the general case of this problem. Modeling challenges of the protocol and the system are addressed. A number of abstractions are utilized in order to reduce the state space. Also, additional innovative state space reduction techniques are introduced that can be used in future verification efforts applied to this and other protocols.
Of Models and Machines: Implementing Bounded Rationality.
Dick, Stephanie
2015-09-01
This essay explores the early history of Herbert Simon's principle of bounded rationality in the context of his Artificial Intelligence research in the mid 1950s. It focuses in particular on how Simon and his colleagues at the RAND Corporation translated a model of human reasoning into a computer program, the Logic Theory Machine. They were motivated by a belief that computers and minds were the same kind of thing--namely, information-processing systems. The Logic Theory Machine program was a model of how people solved problems in elementary mathematical logic. However, in making this model actually run on their 1950s computer, the JOHNNIAC, Simon and his colleagues had to navigate many obstacles and material constraints quite foreign to the human experience of logic. They crafted new tools and engaged in new practices that accommodated the affordances of their machine, rather than reflecting the character of human cognition and its bounds. The essay argues that tracking this implementation effort shows that "internal" cognitive practices and "external" tools and materials are not so easily separated as they are in Simon's principle of bounded rationality--the latter often shaping the dynamics of the former. PMID:26685521
A conceptual model of check dam hydraulics for gully control
Directory of Open Access Journals (Sweden)
C. Castillo
2013-09-01
Full Text Available There is little information in scientific literature regarding the modifications induced by check dam systems in flow regimes in restored gully reaches, despite it being a crucial issue for the design of conservation measures. Here, we develop a conceptual model to classify flow regimes in straight rectangular channels for initial and dam-filling conditions as well as a method of estimating efficiency in order to provide guidelines for optimal design. The model integrates several previous mathematical approaches for assessing the main processes involved (hydraulic jump HJ, impact flow, gradually varied flows. Its performance was compared with the simulations obtained from IBER, a bi-dimensional hydrodynamic model. The impact of check dam spacing (defined by the geometric factor of influence c on efficiency was explored. Eleven main classifications of flow regimes were identified depending on the element and level of influence. The model produced similar results when compared with IBER, but led to higher estimations of HJ and impact lengths. Total influence guaranteed maximum efficiency and HJ control defining the location of the optimal c. Geometric total influence (c = 1 was a valid criterion for the different stages of the structures in a wide range of situations provided that hydraulic roughness conditions remained high within the gully, e.g. through revegetation. Our total influence criterion involved shorter spacing than that habitually recommended in technical manuals for restoration, but was in line with those values found in spontaneous and stable step-pools systems, which might serve as a reference for man-made interventions.
Take it NP-easy: Bounded model construction for duration calculus
DEFF Research Database (Denmark)
Fränzle, Martin
Following the recent successes of bounded model-checking, we reconsider the problem of constructing models of discrete-time Duration Calculus formulae. While this problem is known to be non-elementary when arbitrary length models are considered [Hansen94], it turns out to be only NP-complete when...... constrained to bounded length. As a corollary we obtain that model construction is in NP for the formulae actually encountered in case studies using Duration Calculus, as these have a certain small-model property. First experiments with a prototype implementation of the procedures demonstrate a competitive...
Valuation models and Simon's bounded rationality
Directory of Open Access Journals (Sweden)
Alexandra Strommer de Farias Godoi
2009-09-01
Full Text Available This paper aims at reconciling the evidence that sophisticated valuation models are increasingly used by companies in their investment appraisal with the literature of bounded rationality, according to which objective optimization is impracticable in the real world because it would demand an immense level of sophistication of the analytical and computational processes of human beings. We show how normative valuation models should rather be viewed as forms of reality representation, frameworks according to which the real world is perceived, fragmented for a better understanding, and recomposed, providing an orderly method for undertaking a task as complex as the investment decision.
Combining Decision Diagrams and SAT Procedures for Efficient Symbolic Model Checking
DEFF Research Database (Denmark)
Williams, Poul Frederick; Biere, Armin; Clarke, Edmund M.;
2000-01-01
, combined with BDDs and SAT-solvers to perform satisfiability checking. As a result we are able to model check systems for which standard BDD-based methods fail. For example, we model check a liveness property of a 256 bit shift-and-add multiplier and we are able to find a previously undetected bug...
A Succinct Approach to Static Analysis and Model Checking
DEFF Research Database (Denmark)
Filipiuk, Piotr
In a number of areas software correctness is crucial, therefore it is often desirable to formally verify the presence of various properties or the absence of errors. This thesis presents a framework for concisely expressing static analysis and model checking problems. The framework facilitates...... guarantees that there always is single best solution for a problem under consideration. We also develop a solving algorithm, based on a dierential worklist, that computes the least solution guaranteed by the Moore Family result. Furthermore, we present a logic for specifying analysis problems called Layered...... Fixed Point Logic. Its most prominent feature is the direct support for both inductive computations of behaviors as well as co-inductive specications of properties. Two main theoretical contributions are a Moore Family result and a parametrized worst-case time complexity result. We develop a BDD...
Analysis of the Security of BB84 by Model Checking
Elboukhari, Mohamed; Azizi, Abdelmalek; 10.5121/ijnsa.2010.2207
2010-01-01
Quantum Cryptography or Quantum key distribution (QKD) is a technique that allows the secure distribution of a bit string, used as key in cryptographic protocols. When it was noted that quantum computers could break public key cryptosystems based on number theory extensive studies have been undertaken on QKD. Based on quantum mechanics, QKD offers unconditionally secure communication. Now, the progress of research in this field allows the anticipation of QKD to be available outside of laboratories within the next few years. Efforts are made to improve the performance and reliability of the implemented technologies. But several challenges remain despite this big progress. The task of how to test the apparatuses of QKD For example did not yet receive enough attention. These devises become complex and demand a big verification effort. In this paper we are interested in an approach based on the technique of probabilistic model checking for studying quantum information. Precisely, we use the PRISM tool to analyze ...
Analysis of the Security of BB84 by Model Checking
Directory of Open Access Journals (Sweden)
Mohamed Elboukhari
2010-04-01
Full Text Available Quantum Cryptography or Quantum key distribution (QKD is a technique that allows the secure distribution of a bit string, used as key in cryptographic protocols. When it was noted that quantum computers could break public key cryptosystems based on number theory extensive studies have been undertaken on QKD. Based on quantum mechanics, QKD offers unconditionally secure communication. Now, the progress of research in this field allows the anticipation of QKD to be available outside of laboratories within the next few years. Efforts are made to improve the performance and reliability of the implemented technologies. But several challenges remain despite this big progress. The task of how to test the apparatuses of QKD For example did not yet receive enough attention. These devises become complex and demand a big verification effort. In this paper we are interested in an approach based on the technique of probabilistic model checking for studying quantum information. Precisely, we use the PRISM tool to analyze the security of BB84 protocol and we are focused on the specific security property of eavesdropping detection. We show that this property is affected by the parameters of quantum channel and the power of eavesdropper
Optimisation of BPMN Business Models via Model Checking
DEFF Research Database (Denmark)
Herbert, Luke Thomas; Sharp, Robin
2013-01-01
synthesized BPMN components, based on probabilistic computation tree logic and real-valued reward structures of the BPMN model, allowing for the specification of complex quantitative goals. We here present a simple algorithm, inspired by concepts from evolutionary algorithms, which iteratively generates...
Model Checking of a Diabetes-Cancer Model
Gong, Haijun; Zuliani, Paolo; Clarke, Edmund M.
2011-06-01
Accumulating evidence suggests that cancer incidence might be associated with diabetes mellitus, especially Type II diabetes which is characterized by hyperinsulinaemia, hyperglycaemia, obesity, and overexpression of multiple WNT pathway components. These diabetes risk factors can activate a number of signaling pathways that are important in the development of different cancers. To systematically understand the signaling components that link diabetes and cancer risk, we have constructed a single-cell, Boolean network model by integrating the signaling pathways that are influenced by these risk factors to study insulin resistance, cancer cell proliferation and apoptosis. Then, we introduce and apply the Symbolic Model Verifier (SMV), a formal verification tool, to qualitatively study some temporal logic properties of our diabetes-cancer model. The verification results show that the diabetes risk factors might not increase cancer risk in normal cells, but they will promote cell proliferation if the cell is in a precancerous or cancerous stage characterized by losses of the tumor-suppressor proteins ARF and INK4a.
Using Stochastic Model Checking to Provision Complex Business Services
DEFF Research Database (Denmark)
Herbert, Luke Thomas; Sharp, Robin
2012-01-01
We present a framework for modelling and analysis of real-world business workflows. Business processes regularly form the basis for the design of software services, and frequently display complex stochastic behaviour. The accurate evaluation of their qualitative aspects can allow for determining ...... of business processes including transient probabilities, timing, occurrence and ordering of events, and best- and worst-case scenarios. The developments presented are illustrated using an example from the health-care industry.......We present a framework for modelling and analysis of real-world business workflows. Business processes regularly form the basis for the design of software services, and frequently display complex stochastic behaviour. The accurate evaluation of their qualitative aspects can allow for determining...... bounds on resources consumed during execution of business processes. Accurate resource provisioning is often central to ensuring the safe execution of a process. We first introduce a formalised core subset of the Business Process Modelling and Notation (BPMN), which we extend with probabilistic and non...
The Modeling Library of Eavesdropping Methods in Quantum Cryptography Protocols by Model Checking
Yang, Fan; Yang, Guowu; Hao, Yujie
2016-07-01
The most crucial issue of quantum cryptography protocols is its security. There exists many ways to attack the quantum communication process. In this paper, we present a model checking method for modeling the eavesdropping in quantum information protocols. So when the security properties of a certain protocol are needed to be verified, we can directly use the models which are already built. Here we adopt the probabilistic model checking tool—PRISM to model these attack methods. The verification results show that the detection rate of eavesdropping is approximately close to 1 when enough photons are transmitted.
The Modeling Library of Eavesdropping Methods in Quantum Cryptography Protocols by Model Checking
Yang, Fan; Yang, Guowu; Hao, Yujie
2016-03-01
The most crucial issue of quantum cryptography protocols is its security. There exists many ways to attack the quantum communication process. In this paper, we present a model checking method for modeling the eavesdropping in quantum information protocols. So when the security properties of a certain protocol are needed to be verified, we can directly use the models which are already built. Here we adopt the probabilistic model checking tool—PRISM to model these attack methods. The verification results show that the detection rate of eavesdropping is approximately close to 1 when enough photons are transmitted.
The Complexity of Model Checking Higher-Order Fixpoint Logic
DEFF Research Database (Denmark)
Axelsson, Roland; Lange, Martin; Somla, Rafal
2007-01-01
Higher Order Fixpoint Logic (HFL) is a hybrid of the simply typed λ-calculus and the modal μ-calculus. This makes it a highly expressive temporal logic that is capable of expressing various interesting correctness properties of programs that are not expressible in the modal μ-calculus. This paper...... of solving rather large parity games of small index. As a consequence of this we obtain an ExpTime upper bound on the expression complexity of each HFLk,m. The lower bound is established by a reduction from the word problem for alternating (k-1)-fold exponential space bounded Turing Machines. As a...
Family-Based Model Checking Without a Family-Based Model Checker
DEFF Research Database (Denmark)
Dimovski, Aleksandar; Al-Sibahi, Ahmad Salim; Brabrand, Claus; Wasowski, Andrzej
Many software systems are variational: they can be configured to meet diverse sets of requirements. Variability is found in both communication protocols and discrete controllers of embedded systems. In these areas, model checking is an important verification technique. For variational models...
PVeStA: A Parallel Statistical Model Checking and Quantitative Analysis Tool
AlTurki, Musab
2011-01-01
Statistical model checking is an attractive formal analysis method for probabilistic systems such as, for example, cyber-physical systems which are often probabilistic in nature. This paper is about drastically increasing the scalability of statistical model checking, and making such scalability of analysis available to tools like Maude, where probabilistic systems can be specified at a high level as probabilistic rewrite theories. It presents PVeStA, an extension and parallelization of the VeStA statistical model checking tool [10]. PVeStA supports statistical model checking of probabilistic real-time systems specified as either: (i) discrete or continuous Markov Chains; or (ii) probabilistic rewrite theories in Maude. Furthermore, the properties that it can model check can be expressed in either: (i) PCTL/CSL, or (ii) the QuaTEx quantitative temporal logic. As our experiments show, the performance gains obtained from parallelization can be very high. © 2011 Springer-Verlag.
Model checking and strategy synthesis for stochastic games: from theory to practice
Kwiatkowska, MZ
2016-01-01
Probabilistic model checking is an automatic procedure for establishing if a desired property holds in a probabilistic model, aimed at verifying quantitative probabilistic specifications such as the probability of a critical failure occurring or expected time to termination. Much progress has been made in recent years in algorithms, tools and applications of probabilistic model checking, as exemplified by the probabilistic model checker PRISM (www.prismmodelchecker.org). However, the unstoppa...
Checking Fine and Gray Subdistribution Hazards Model with Cumulative Sums of Residuals
Li, Jianing; Scheike, Thomas H.; Zhang, Mei-Jie
2014-01-01
Recently, Fine and Gray (1999) proposed a semi-parametric proportional regression model for the subdistribution hazard function which has been used extensively for analyzing competing risks data. However, failure of model adequacy could lead to severe bias in parameter estimation, and only a limited contribution has been made to check the model assumptions. In this paper, we present a class of analytical methods and graphical approaches for checking the assumptions of Fine and Gray’s model. T...
A logic for model-checking of mean-field models
Kolesnichenko, Anna; Remke, Anne; Boer, de, J.W.; Haverkort, Boudewijn R.
2012-01-01
Recently, many systems consisting of a large number of interacting objects were analysed using the mean-field method, which has only been used for performance evaluation. In this short paper, we apply it to model checking. We define logic, which allows to describe the overall properties of the large system.
Lower bounds in the quantum cell probe model
Sen, Pranab; Venkatesh, S.
2001-01-01
We introduce a new model for studying quantum data structure problems -- the "quantum cell probe model". We prove a lower bound for the static predecessor problem in the address-only version of this model where we allow quantum parallelism only over the `address lines' of the queries. The address-only quantum cell probe model subsumes the classical cell probe model, and many quantum query algorithms like Grover's algorithm fall into this framework. Our lower bound improves the previous known ...
Development of a butterfly check valve model under natural circulation conditions
International Nuclear Information System (INIS)
Highlights: • Bases on Lim’s swing check valve model, a butterfly check valve model was developed. • The method to quantify the friction torque TF in Li’s model was corrected. • The developed model was implemented into the RELAP5 code and verified. - Abstract: A butterfly check valve is widely used to prevent a reverse flow in the pipe lines of a marine nuclear power plant. Under some conditions, the natural circulation conditions in particular, the fluid velocity through the butterfly check valve might become too low to hold the valve disk fully open, thereby the flow resistance of the butterfly check valve varies with the location of the valve disk and as a result the fluid flow is significantly affected by the dynamic motion of the valve disk. Simulation of a pipe line that includes some butterfly check valves, especially under natural circulation conditions, is thus complicated. This paper focuses on the development of a butterfly check valve model to enhance the capability of the thermal–hydraulic system code and the developed model is implemented into the RELAP5 code. Both steady-state calculations and transient calculations were carried out for the primary loop system of a marine nuclear power plant and the calculation results are compared with the experimental data for verification purpose. The simulation results show an agreement with the experimental data
LHCb: Analysing DIRAC's Behavior using Model Checking with Process Algebra
Remenska, Daniela
2012-01-01
DIRAC is the Grid solution designed to support LHCb production activities as well as user data analysis. Based on a service-oriented architecture, DIRAC consists of many cooperating distributed services and agents delivering the workload to the Grid resources. Services accept requests from agents and running jobs, while agents run as light-weight components, fulfilling specific goals. Services maintain database back-ends to store dynamic state information of entities such as jobs, queues, staging requests, etc. Agents use polling to check for changes in the service states, and react to these accordingly. A characteristic of DIRAC's architecture is the relatively low complexity in the logic of each agent; the main source of complexity lies in their cooperation. These agents run concurrently, and communicate using the services' databases as a shared memory for synchronizing the state transitions. Although much effort is invested in making DIRAC reliable, entities occasionally get into inconsistent states, leadi...
Checking the new IRI model The bottomside B parameters
Mosert, M; Ezquer, R; Lazo, B; Miro, G
2002-01-01
Electron density profiles obtained at Pruhonice (50.0, 15.0), El Arenosillo (37.1, 353.2) and Havana (23, 278) were used to check the bottom-side B parameters BO (thickness parameter) and B1 (shape parameter) predicted by the new IRI - 2000 version. The electron density profiles were derived from ionograms using the ARP technique. The data base includes daytime and nighttime ionograms recorded under different seasonal and solar activity conditions. Comparisons with IRI predictions were also done. The analysis shows that: a) The parameter B1 given by IRI 2000 reproduces better the observed ARP values than the IRI-90 version and b) The observed BO values are in general well reproduced by both IRI versions: IRI-90 and IRI-2000.
A branch-and-bound methodology within algebraic modelling systems
Bisschop, J.J.; Heerink, J.B.J.; Kloosterman, G.
1998-01-01
Through the use of application-specific branch-and-bound directives it is possible to find solutions to combinatorial models that would otherwise be difficult or impossible to find by just using generic branch-and-bound techniques within the framework of mathematical programming. {\\sc Minto} is an example of a system which offers the possibility to incorporate user-provided directives (written in {\\sc C}) to guide the branch-and-bound search. Its main focus, however, remains on mathematical p...
Model Checking of Software Components: Combining Java PathFinder and Behavior Protocol Model Checker
Czech Academy of Sciences Publication Activity Database
Pařízek, P.; Plášil, František; Kofroň, Jan
Los Alamitos: IEEE Computer Society, 2006, s. 133-141. ISBN 0-7695-2624-1. [SEW 2006. Annual IEEE/NASA Software Engineering Workshop /30./. Loyola College Graduate Center, Columbia (US), 24.04.2006-28.04.2006] R&D Projects: GA ČR GA201/06/0770 Institutional research plan: CEZ:AV0Z10300504 Keywords : software components * behavior protocols * model checking * cooperation of model checkers Subject RIV: JC - Computer Hardware ; Software
An Approach to Checking 3D Model with Related Engineering Drawings
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
For some reasons, engineers build their product 3D mo del according to a set of related engineering drawings. The problem is how we ca n know the 3D model is correct. The manual checking is very boring and time cons uming, and still could not avoid mistakes. Thus, we could not confirm the model, maybe try checking again. It will effect the production preparing cycle greatly , and should be solved in a intelligent way. The difficulties are quite obvious, unlike word checking in a word processing package, ...
Efficient model checking for duration calculus based on branching-time approximations
DEFF Research Database (Denmark)
Fränzle, Martin; Hansen, Michael Reichhardt
2008-01-01
Duration Calculus (abbreviated to DC) is an interval-based, metric-time temporal logic designed for reasoning about embedded real-time systems at a high level of abstraction. But the complexity of model checking any decidable fragment featuring both negation and chop, DC's only modality, is non......-elementary and thus impractical. We here investigate a similar approximation as frequently employed in model checking situation-based temporal logics, where linear-time problems are safely approximated by branching-time counterparts amenable to more efficient model-checking algorithms. Mimicking the role that a...... situation has in (A)CTL as origin of a set of linear traces, we define a branching-time counterpart to interval-based temporal logics building on situation pairs spanning sets of intervals. While this branching-time interval semantics yields the desired reduction in complexity of the model-checking problem...
Efficient Symmetry Reduction and the Use of State Symmetries for Symbolic Model Checking
Directory of Open Access Journals (Sweden)
Christian Appold
2010-06-01
Full Text Available One technique to reduce the state-space explosion problem in temporal logic model checking is symmetry reduction. The combination of symmetry reduction and symbolic model checking by using BDDs suffered a long time from the prohibitively large BDD for the orbit relation. Dynamic symmetry reduction calculates representatives of equivalence classes of states dynamically and thus avoids the construction of the orbit relation. In this paper, we present a new efficient model checking algorithm based on dynamic symmetry reduction. Our experiments show that the algorithm is very fast and allows the verification of larger systems. We additionally implemented the use of state symmetries for symbolic symmetry reduction. To our knowledge we are the first who investigated state symmetries in combination with BDD based symbolic model checking.
Validation of mission critical software design and implementation using model checking
Pingree, P. J.; Mikk, E.; Holzmann, G.; Smith, M.; Dams, D.
2002-01-01
Model Checking conducts an exhaustive exploration of all possible behaviors of a software system design and as such can be used to detect defects in designs that are typically difficult to discover with conventional testing approaches.
Deterministic Compilation of Temporal Safety Properties in Explicit State Model Checking
National Aeronautics and Space Administration — The translation of temporal logic specifications constitutes an essen- tial step in model checking and a major influence on the efficiency of formal verification...
Towards Symbolic Model Checking for Multi-Agent Systems via OBDDs
Raimondi, Franco; Lomunscio, Alessio
2004-01-01
We present an algorithm for model checking temporal-epistemic properties of multi-agent systems, expressed in the formalism of interpreted systems. We first introduce a technique for the translation of interpreted systems into boolean formulae, and then present a model-checking algorithm based on this translation. The algorithm is based on OBDD's, as they offer a compact and efficient representation for boolean formulae.
Phase Two Feasibility Study for Software Safety Requirements Analysis Using Model Checking
Turgeon, Gregory; Price, Petra
2010-01-01
A feasibility study was performed on a representative aerospace system to determine the following: (1) the benefits and limitations to using SCADE , a commercially available tool for model checking, in comparison to using a proprietary tool that was studied previously [1] and (2) metrics for performing the model checking and for assessing the findings. This study was performed independently of the development task by a group unfamiliar with the system, providing a fresh, external perspective free from development bias.
Energy Technology Data Exchange (ETDEWEB)
Lahtinen, J. [VTT Technical Research Centre of Finland, Espoo (Finland); Launiainen, T.; Heljanko, K.; Ropponen, J. [Aalto Univ., Espoo (Finland). Dept. of Information and Computer Science
2012-07-01
Digital instrumentation and control (I and C) systems are challenging to verify. They enable complicated control functions, and the state spaces of the models easily become too large for comprehensive verification through traditional methods. Model checking is a formal method that can be used for system verification. A number of efficient model checking systems are available that provide analysis tools to determine automatically whether a given state machine model satisfies the desired safety properties. This report reviews the work performed in the Safety Evaluation and Reliability Analysis of Nuclear Automation (SARANA) project in 2011 regarding model checking. We have developed new, more exact modelling methods that are able to capture the behaviour of a system more realistically. In particular, we have developed more detailed fault models depicting the hardware configuration of a system, and methodology to model function-block-based systems asynchronously. In order to improve the usability of our model checking methods, we have developed an algorithm for model checking large modular systems. The algorithm can be used to verify properties of a model that could otherwise not be verified in a straightforward manner. (orig.)
Verifying Real-time Commit Protocols Using Dense-time Model Checking Technology
Al-Bataineh, Omar I.; Reynolds, Mark; French, Tim; Woodings, Terry
2012-01-01
The timed-based automata model, introduced by Alur and Dill, provides a useful formalism for describing real-time systems. Over the last two decades, several dense-time model checking tools have been developed based on that model. The paper considers the verification of real-time distributed commit protocols using dense-time model checking technology. More precisely, we model and verify the well-known timed two phase commit protocol in three different state-of-the-art real-time model checkers...
Verifying Real-time Commit Protocols Using Dense-time Model Checking Technology
Al-Bataineh, Omar I; French, Tim; Woodings, Terry
2012-01-01
The timed-based automata model, introduced by Alur and Dill, provides a useful formalism for describing real-time systems. Over the last two decades, several dense-time model checking tools have been developed based on that model. The paper considers the verification of real-time distributed commit protocols using dense-time model checking technology. More precisely, we model and verify the well-known timed two phase commit protocol in three different state-of-the-art real-time model checkers: UPPAAL, Rabbit, and RED, and compare the results.
PKreport: report generation for checking population pharmacokinetic model assumptions
Directory of Open Access Journals (Sweden)
Li Jun
2011-05-01
Full Text Available Abstract Background Graphics play an important and unique role in population pharmacokinetic (PopPK model building by exploring hidden structure among data before modeling, evaluating model fit, and validating results after modeling. Results The work described in this paper is about a new R package called PKreport, which is able to generate a collection of plots and statistics for testing model assumptions, visualizing data and diagnosing models. The metric system is utilized as the currency for communicating between data sets and the package to generate special-purpose plots. It provides ways to match output from diverse software such as NONMEM, Monolix, R nlme package, etc. The package is implemented with S4 class hierarchy, and offers an efficient way to access the output from NONMEM 7. The final reports take advantage of the web browser as user interface to manage and visualize plots. Conclusions PKreport provides 1 a flexible and efficient R class to store and retrieve NONMEM 7 output, 2 automate plots for users to visualize data and models, 3 automatically generated R scripts that are used to create the plots; 4 an archive-oriented management tool for users to store, retrieve and modify figures, 5 high-quality graphs based on the R packages, lattice and ggplot2. The general architecture, running environment and statistical methods can be readily extended with R class hierarchy. PKreport is free to download at http://cran.r-project.org/web/packages/PKreport/index.html.
Model-Checking Real-Time Control Programs
DEFF Research Database (Denmark)
Iversen, T. K.; Kristoffersen, K. J.; Larsen, Kim Guldstrand; Laursen, M.; Madsen, R. G.; Mortensen, S. K.; Pettersson, P.; Thomasen, C. B.
In this paper, we present a method for automatic verification of real-time control programs running on LEGO(R) RCX(TM) bricks using the verification tool UPPALL. The control programs, consisting of a number of tasks running concurrently, are automatically translated into the mixed automata model of...... UPPAAL. The fixed scheduling algorithm used by the LEGO(R) RCX(TM) processor is modeled in UPPALL, and supply of similar (sufficient) timed automata models for the environment allows analysis of the overall real-time system using the tools of UPPALL. To illustrate our technique for sorting LEGO(R) bricks...
Cosmological bounds on oscillating dark energy models
International Nuclear Information System (INIS)
We study the cosmological constraints on the two purely phenomenological models of oscillating dark energy. In these oscillating models, the equation of state of dark energy varies periodically. The periodic equation of state may provide the natural way to unify the early acceleration (inflation) and the late time acceleration of the Universe. These models give the effective way to tackle the cosmic coincidence problem. We examine the observational constraints on the oscillatory models from the latest observational data including the gold sample of 182 SNe type Ia, the shift parameter, R, given by the WMAP and the BAO measurements from the SDSS
Practical Application of Model Checking in Software Verification
Havelund, Klaus; Skakkebaek, Jens Ulrik
1999-01-01
This paper presents our experiences in applying the JAVA PATHFINDER (J(sub PF)), a recently developed JAVA to SPIN translator, in the finding of synchronization bugs in a Chinese Chess game server application written in JAVA. We give an overview of J(sub PF) and the subset of JAVA that it supports and describe the abstraction and verification of the game server. Finally, we analyze the results of the effort. We argue that abstraction by under-approximation is necessary for abstracting sufficiently smaller models for verification purposes; that user guidance is crucial for effective abstraction; and that current model checkers do not conveniently support the computational models of software in general and JAVA in particular.
Application of Model-Checking Technology to Controller Synthesis
DEFF Research Database (Denmark)
David, Alexandre; Grunnet, Jacob Deleuran; Jessen, Jan Jacob;
2011-01-01
its continuous environment, which is modelled and taken care of in our frameworks. Our first technique does it by using Matlab to discretise the problem and then Uppaal-tiga to solve the obtained timed game. This is implemented as a toolbox. The second technique relies on the user defining a timed...... game model in Uppaal- tiga. Then the strategy is automatically imported in Simulink as an S-function for simulation and validation purposes. We demonstrate the effectiveness of these frameworks in different case-studies....
Model Checking Electronic Commerce Security Protocols Based on CTL
Institute of Scientific and Technical Information of China (English)
XIAO De-qin; ZHANG Huan-guo
2005-01-01
We present a model based on Computational Temporal Logic (CTL) methods for verifying security requirements of electronic commerce protocols. The model describes formally the authentication, confidentiality integrity,non-repudiation, denial of service and access control of the electronic commerce protocols. We illustrate as case study a variant of the Lu-Smolka protocol proposed by Lu-Smolka.Moreover, we have discovered two attacks that allow a dishonest user to purchase a good debiting the amount to another user. And also, we compared our work with relative research works and found that the formal way of this paper is more general to specify security protocols for E-Commerce.
VERIFICATION OF CONFLICTION AND UNREACHABILITY IN RULE-BASED EXPERT SYSTEMS WITH MODEL CHECKING
Directory of Open Access Journals (Sweden)
Einollah pira
2014-03-01
Full Text Available It is important to find optimal solutions for structural errors in rule-based expert systems .Solutions to discovering such errors by using model checking techniques have already been proposed, but these solutions have problems such as state space explosion. In this paper, to overcome these problems, we model the rule-based systems as finite state transition systems and express confliction and unreachabilityas Computation Tree Logic (CTL logic formula and then use the technique of model checking to detect confliction and unreachability in rule-based systems with the model checker UPPAAL.
Vulnerable Derivatives and Good Deal Bounds: A Structural Model
DEFF Research Database (Denmark)
Murgoci, Agatha
2013-01-01
new restriction in the arbitrage free model by setting upper bounds on the Sharpe ratios (SRs) of the assets. The potential prices that are eliminated represent unreasonably good deals. The constraint on the SR translates into a constraint on the stochastic discount factor. Thus, tight pricing bounds...... can be obtained. We provide a link between the objective probability measure and the range of potential risk-neutral measures, which has an intuitive economic meaning. We also provide tight pricing bounds for European calls and show how to extend the call formula to pricing other financial products in...
Hypersonic: Model Analysis and Checking in the Cloud
DEFF Research Database (Denmark)
Acretoaie, Vlad; Störrle, Harald
2014-01-01
”. Objective: In this paper we investigate the conceptual and technical feasibility of a new software architecture for modeling tools, where certain advanced features are factored out of the client and moved towards the Cloud. With this approach we plan to address the above mentioned drawbacks of existing...
Membrane Matrix models and non-perturbative checks of gauge/gravity duality
O'Connor, Denjoe
2016-01-01
We compare the bosonic and maximally supersymmetric membrane models. We find that in Hoppe regulated form the bosonic membrane is well approximated by massive Gaussian quantum matrix models. In contrast the similarly regulated supersymmetric membrane, which is equivalent to the BFSS model, has a gravity dual description. We sketch recent progress in checking gauge/gravity duality in this context.
Using Runtime Analysis to Guide Model Checking of Java Programs
Havelund, Klaus; Norvig, Peter (Technical Monitor)
2001-01-01
This paper describes how two runtime analysis algorithms, an existing data race detection algorithm and a new deadlock detection algorithm, have been implemented to analyze Java programs. Runtime analysis is based on the idea of executing the program once. and observing the generated run to extract various kinds of information. This information can then be used to predict whether other different runs may violate some properties of interest, in addition of course to demonstrate whether the generated run itself violates such properties. These runtime analyses can be performed stand-alone to generate a set of warnings. It is furthermore demonstrated how these warnings can be used to guide a model checker, thereby reducing the search space. The described techniques have been implemented in the b e grown Java model checker called PathFinder.
Optimizing algebraic petri net model checking by slicing
Khan, Yasir Imtiaz; Risoldi, Matteo
2013-01-01
High-level Petri nets make models more concise and read- able as compared to low-level Petri nets. However, usual verification techniques such as state space analysis remain an open challenge for both because of state space explosion. The contribution of this paper is to propose an approach for property based reduction of the state space of Algebraic Petri nets (a variant of high-level Petri nets). To achieve the objective, we propose a slicing algorithm for Algebraic Petri ...
Model Checking of E-Commerce Protocol using Casper FDR
Dantuluri Sravanthi
2013-01-01
In present days the popularity of electronic commerce applications are motivated the development of new e-commerce protocols. By using these new protocols the secrecy and agreement properties are achieved. This paper mainly focuses on how to model the e-commerce protocol in CSP using SPL and verified using CasperFDR whether the protocol satisfies the properties specified. Attacks are identified in this version. The specifications through which these attacks are found are presented.
Numerical modelling of granular flows: a reality check
Windows-Yule, C. R. K.; Tunuguntla, D. R.; Parker, D. J.
2016-07-01
Discrete particle simulations provide a powerful tool for the advancement of our understanding of granular media, and the development and refinement of the multitudinous techniques used to handle and process these ubiquitous materials. However, in order to ensure that this tool can be successfully utilised in a meaningful and reliable manner, it is of paramount importance that we fully understand the degree to which numerical models can be trusted to accurately and quantitatively recreate and predict the behaviours of the real-world systems they are designed to emulate. Due to the complexity and diverse variety of physical states and dynamical behaviours exhibited by granular media, a simulation algorithm capable of closely reproducing the behaviours of a given system may be entirely unsuitable for other systems with different physical properties, or even similar systems exposed to differing control parameters. In this paper, we focus on two widely used forms of granular flow, for which discrete particle simulations are shown to provide a full, quantitative replication of the behaviours of real industrial and experimental systems. We identify also situations for which quantitative agreement may fail are identified, but important general, qualitative trends are still recreated, as well as cases for which computational models are entirely unsuitable. By assembling this information into a single document, we hope not only to provide researchers with a useful point of reference when designing and executing future studies, but also to equip those involved in the design of simulation algorithms with a clear picture of the current strengths and shortcomings of contemporary models, and hence an improved knowledge of the most valuable areas on which to focus their work.
Numerical modelling of granular flows: a reality check
Windows-Yule, C. R. K.; Tunuguntla, D. R.; Parker, D. J.
2015-12-01
Discrete particle simulations provide a powerful tool for the advancement of our understanding of granular media, and the development and refinement of the multitudinous techniques used to handle and process these ubiquitous materials. However, in order to ensure that this tool can be successfully utilised in a meaningful and reliable manner, it is of paramount importance that we fully understand the degree to which numerical models can be trusted to accurately and quantitatively recreate and predict the behaviours of the real-world systems they are designed to emulate. Due to the complexity and diverse variety of physical states and dynamical behaviours exhibited by granular media, a simulation algorithm capable of closely reproducing the behaviours of a given system may be entirely unsuitable for other systems with different physical properties, or even similar systems exposed to differing control parameters. In this paper, we focus on two widely used forms of granular flow, for which discrete particle simulations are shown to provide a full, quantitative replication of the behaviours of real industrial and experimental systems. We identify also situations for which quantitative agreement may fail are identified, but important general, qualitative trends are still recreated, as well as cases for which computational models are entirely unsuitable. By assembling this information into a single document, we hope not only to provide researchers with a useful point of reference when designing and executing future studies, but also to equip those involved in the design of simulation algorithms with a clear picture of the current strengths and shortcomings of contemporary models, and hence an improved knowledge of the most valuable areas on which to focus their work.
A Check-up for the Statistical Parton Model
Buccella, Franco
2014-01-01
We compare the parton distributions deduced in the framework of a quantum statistical approach for both the longitudinal and transverse degrees of freedom with the unpolarized distributions measured at Hera and with the polarized ones proposed in a previous paper, which have been shown to be in very good agreement also with the results of experiments performed after that proposal. The agreement with Hera data in correspondence of very similar values for the 'temperature' and the 'potentials' found in the previous work gives a robust confirm of the statistical model. The feature of describing both unpolarized and polarized parton distributions in terms of few parameters fixed by data with large statistics and small systematic errors makes very attractive the parametrization proposed here.
A check-up for the statistical Parton model
Buccella, Franco; Sohaily, Sozha
2015-11-01
We compare the Parton distributions deduced in the framework of a quantum statistical approach for both the longitudinal and transverse degrees of freedom with the unpolarized distributions measured at HERA and with the polarized ones proposed in a previous paper, which have been shown to be in very good agreement also with the results of experiments performed after that proposal. The agreement with HERA data in correspondence to very similar values for the “temperature” and the “potentials” found in the previous work gives a robust confirm of the statistical model. The unpolarized distributions are compared also with the result of NNPDF. The free parameters are fixed mainly by data in the range (0.1, 0.5) for the x variable, where the valence Partons dominate, and in the small x region for the diffractive contribution. This feature makes the parametrization proposed here very attractive.
Prototype of Automated PLC Model Checking Using Continuous Integration Tools
Lettrich, Michael
2015-01-01
To deal with the complexity of operating and supervising large scale industrial installations at CERN, often Programmable Logic Controllers (PLCs) are used. A failure in these control systems can cause a disaster in terms of economic loses, environmental damages or human losses. Therefore the requirements to software quality are very high. To provide PLC developers with a way to verify proper functionality against requirements, a Java tool named PLCverif has been developed which encapsulates and thus simplifies the use of third party model checkers. One of our goals in this project is to integrate PLCverif in development process of PLC programs. When the developer changes the program, all the requirements should be verified again, as a change on the code can produce collateral effects and violate one or more requirements. For that reason, PLCverif has been extended to work with Jenkins CI in order to trigger automatically the verication cases when the developer changes the PLC program. This prototype has been...
Cascading Verification: An Integrated Method for Domain-Specific Model Checking
Zervoudakis, F.
2014-01-01
Model checking is an established formal method for verifying the desired behavioral properties of system models. But popular model checkers tend to support low-level modeling languages that require intricate models to represent even the simplest systems. Modeling complexity arises in part from the need to encode domain knowledge, including domain objects and concepts, and their relationships, at relatively low levels of abstraction. We will demonstrate that, once formalized, domain knowledge ...
Model Checking Real Time Java Using Java PathFinder
Lindstrom, Gary; Mehlitz, Peter C.; Visser, Willem
2005-01-01
The Real Time Specification for Java (RTSJ) is an augmentation of Java for real time applications of various degrees of hardness. The central features of RTSJ are real time threads; user defined schedulers; asynchronous events, handlers, and control transfers; a priority inheritance based default scheduler; non-heap memory areas such as immortal and scoped, and non-heap real time threads whose execution is not impeded by garbage collection. The Robust Software Systems group at NASA Ames Research Center has JAVA PATHFINDER (JPF) under development, a Java model checker. JPF at its core is a state exploring JVM which can examine alternative paths in a Java program (e.g., via backtracking) by trying all nondeterministic choices, including thread scheduling order. This paper describes our implementation of an RTSJ profile (subset) in JPF, including requirements, design decisions, and current implementation status. Two examples are analyzed: jobs on a multiprogramming operating system, and a complex resource contention example involving autonomous vehicles crossing an intersection. The utility of JPF in finding logic and timing errors is illustrated, and the remaining challenges in supporting all of RTSJ are assessed.
Gamble, Ed; Holzmann, Gerard
2011-01-01
Part of the US DOT investigation of Toyota SUA involved analysis of the throttle control software. JPL LaRS applied several techniques, including static analysis and logic model checking, to the software. A handful of logic models were built. Some weaknesses were identified; however, no cause for SUA was found. The full NASA report includes numerous other analyses
Requirements-level semantics and model checking of object-oriented statecharts
Eshuis, Rik; Jansen, David N.; Wieringa, Roel
2002-01-01
In this paper we define a requirements-level execution semantics for object-oriented statecharts and show how properties of a system specified by these statecharts can be model checked using tool support for model checkers. Our execution semantics is requirements-level because it uses the perfect te
Random Testing and Model Checking: Building a Common Framework for Nondeterministic Exploration
Groce, Alex; Joshi, Rajeev
2008-01-01
Two popular forms of dynamic analysis, random testing and explicit-state software model checking, are perhaps best viewed as search strategies for exploring the state spaces introduced by nondeterminism in program inputs. We present an approach that enables this nondeterminism to be expressed in the SPIN model checker's PROMELA language, and then lets users generate either model checkers or random testers from a single harness for a tested C program. Our approach makes it easy to compare model checking and random testing for models with precisely the same input ranges and probabilities and allows us to mix random testing with model checking's exhaustive exploration of non-determinism. The PROMELA language, as intended in its design, serves as a convenient notation for expressing nondeterminism and mixing random choices with nondeterministic choices. We present and discuss a comparison of random testing and model checking. The results derive from using our framework to test a C program with an effectively infinite state space, a module in JPL's next Mars rover mission. More generally, we show how the ability of the SPIN model checker to call C code can be used to extend SPIN's features, and hope to inspire others to use the same methods to implement dynamic analyses that can make use of efficient state storage, matching, and backtracking.
Directory of Open Access Journals (Sweden)
R. Lestari
2012-12-01
Full Text Available Tujuan penelitian tindakan kelas ini untuk mengetahui pengaruh proses pembelajaran dengan menggunakan model pembelajaran kooperatif tipe Pair Checks pemecahan masalah terhadap peningkatan social skill siswa. Pada proses penerapan model pembelajaran kooperatif tipe Pair Checks pemecahan masalah siswa dibagi dalam kelompok-kelompok dan satu kelompok terdiri dari dua orang. Setiap kelompok berdiskusi untuk menyelesaikan suatu masalah, kemudian hasil diskusi kelompok akan dicek oleh pasangan dari kelompok lain. Metode Penelitian yang digunakan adalah penelitian tindakan kelas yang dilaksanakan dua siklus. Metode pengumpulan data menggunakan tes dan angket skala sikap, sedangkan teknik analisis data menggunakan teknik analisis data kuantitatif. Social Skill siswa dari siklus I ke siklus II mengalami peningkatan. Hal ini didapatkan dari data angket skala sikap siklus I ke siklus II ketuntasan klasikalnya meningkat dan sebagian besar siswa sudah memiliki social skill yang baik. Hasil belajar kognitif siswa juga mengalami peningkatan. Model pembelajaran kooperatif tipe Pair Checks pemecahan masalah dapat meningkatkan social skill siswa.This two cycles-action research aimed to know learning process applying cooperative learning model-pair checks problem solving type and improvement of studentâ€™s social skills. The process of the model was as follows: deviding students into some groups consisting of two students, solving problem by each group and checking result of the discussion by other groups. Data collection method used was test and the use of attitude scale questionnaire, while technique of data analysis used was quantitative data analysis technique. The data analysis result showed that there was an increase of studentâ€™s social skill and studentsâ€™ achievement from cycle one to two. It is concluded that cooperative learning model-pair checks problem solving type can enhance studentâ€™s social skills
Electrostatic charge bounds for ball lightning models
International Nuclear Information System (INIS)
Several current theories concerning the nature of ball lightning predict a substantial electrostatic charge in order to account for its observed motion and shape (Turner 1998 Phys. Rep. 293 1; Abrahamson and Dinniss 2000 Nature 403 519). Using charged soap bubbles as a physical model for ball lightning, we show that the magnitude of charge predicted by some of these theories is too high to allow for the types of motion commonly observed in natural ball lightning, which includes horizontal motion above the ground and movement near grounded conductors. Experiments show that at charge levels of only 10-15 nC, 3-cm-diameter soap bubbles tend to be attracted by induced charges to the nearest grounded conductor and rupture. We conclude with a scaling rule that can be used to extrapolate these results to larger objects and surroundings
DiVinE-CUDA - A Tool for GPU Accelerated LTL Model Checking
Directory of Open Access Journals (Sweden)
Jiří Barnat
2009-12-01
Full Text Available In this paper we present a tool that performs CUDA accelerated LTL Model Checking. The tool exploits parallel algorithm MAP adjusted to the NVIDIA CUDA architecture in order to efficiently detect the presence of accepting cycles in a directed graph. Accepting cycle detection is the core algorithmic procedure in automata-based LTL Model Checking. We demonstrate that the tool outperforms non-accelerated version of the algorithm and we discuss where the limits of the tool are and what we intend to do in the future to avoid them.
Model Checking Process Algebra of Communicating Resources for Real-time Systems
DEFF Research Database (Denmark)
Boudjadar, Jalil; Kim, Jin Hyun; Larsen, Kim Guldstrand;
2014-01-01
This paper presents a new process algebra, called PACOR, for real-time systems which deals with resource constrained timed behavior as an improved version of the ACSR algebra. We define PACOR as a Process Algebra of Communicating Resources which allows to express preemptiveness, urgent ness and...... original semantics of PACOR and enables the verification of PACOR systems using symbolic model checking in UPPAAL and statistical model checking UPPAAL SMC. Finally we provide an example to illustrate system specification in PACOR, translation and verification....
Model checking process algebra of communicating resources for real-time systems
DEFF Research Database (Denmark)
Boudjadar, Jalil; Kim, Jin Hyun; Larsen, Kim Guldstrand;
2014-01-01
This paper presents a new process algebra, called PACoR, for real-time systems which deals with resource- constrained timed behavior as an improved version of the ACSR algebra. We define PACoR as a Process Algebra of Communicating Resources which allows to explicitly express preemptiveness...... preserves the original semantics of PACoR and enables the verification of PACoR systems using symbolic model checking in Uppaal and statistical model checking UppaalSMC. Finally we provide an example to illustrate system specification in PACoR, translation and verification....
Quark model study of the triton bound stat
Juliá-Díaz, B.; Fernández, F.; Valcarce, A.; Haidenbauer, J.
2001-01-01
The three-nucleon bound state problem is studied employing nucleon-nucleon potentials derived from a basic quark-quark interaction. We analyze the effects of the nonlocalities generated by the quark model. The calculated triton binding energies indicate that quark-model nonlocalities can yield additional binding in the order of few hundred keV.
Application safety enhancement model using self-checking with software enzymes
Subramaniam, Chandrasekaran; Ravishankar, Arthi; Gopal, Deepthi; Subramanian, Dhaarini
2011-12-01
The objective of the paper is to propose a safety enhancement model for application software in accelerating the respective self checking strategies similar to bio enzymatic actions. The application software components which are safety critical may have to be assessed periodically or on demand to achieve not only the functional correctness but also the safety specifications or features while getting executed. The design and deployment of such software modules can be formally verified for possible safety flaws using self checking capabilities and software enzymatic actions. The self checks must sense the safety holes in the software and decide to activate the built-in software components called enzymes to do the safe guard operations in a timely manner to mitigate the safety faults using the proposed enzyme calculus. The various application hazards due to the boolean faults in the functional and behavioral model that lead to software safety issues are considered in this approach.
Boson bound states in the -Fermi–Pasta–Ulam model
Indian Academy of Sciences (India)
Xin-Guang Hu; Ju Xiang; Zheng Jiao; Yang Liu; Guo-Qiu Xie; Ke Hu
2013-11-01
The bound states of four bosons in the quantum -Fermi–Pasta–Ulam model are investigated and some interesting results are presented using the number conserving approximation combined with the number state method. We find that the relative magnitude of anharmonic coefficient has a significant effect on forming localized energy in the model, and the wave number plays an important role in forming different bound states. The signature of the quantum breather is also set up by the square of the amplitudes of the corresponding eigenvectors in real space.
Nonparametric checks for count data models: an application to demand for health care in Spain
Álvarez, Begoña; Delgado, Miguel A.
1997-01-01
This paper presents model specification checking procedures for count data regression models which are consistent in the direction of nonparametric alternatives. The discussion is motivated in the context of a model of demand for health care in Spain. The parameters of the regression model are estimated by maximum likelihood based on Poisson and Negative Binomial specifications as well as by ordinary least squares and semiparametric generalized least squares. However, our interest is not only...
Incremental checking of Master Data Management model based on contextual graphs
Lamolle, Myriam; Menet, Ludovic; Le Duc, Chan
2015-10-01
The validation of models is a crucial step in distributed heterogeneous systems. In this paper, an incremental validation method is proposed in the scope of a Model Driven Engineering (MDE) approach, which is used to develop a Master Data Management (MDM) field represented by XML Schema models. The MDE approach presented in this paper is based on the definition of an abstraction layer using UML class diagrams. The validation method aims to minimise the model errors and to optimisethe process of model checking. Therefore, the notion of validation contexts is introduced allowing the verification of data model views. Description logics specify constraints that the models have to check. An experimentation of the approach is presented through an application developed in ArgoUML IDE.
Specification and Generation of Environment for Model Checking of Software Components
Czech Academy of Sciences Publication Activity Database
Pařízek, P.; Plášil, František
2007-01-01
Roč. 176, - (2007), s. 143-154. ISSN 1571-0661 R&D Projects: GA AV ČR 1ET400300504 Institutional research plan: CEZ:AV0Z10300504 Keywords : software components * behavior protocols * model checking * automated generation of environment Subject RIV: JC - Computer Hardware ; Software
On Robustness Analysis of Stochastic Biochemical Systems by Probabilistic Model Checking
Brim, Lubos; Ceska, Milan; Drazan, Sven; Safranek, David
2013-01-01
This report proposes a novel framework for a rigorous robustness analysis of stochastic biochemical systems. The technique is based on probabilistic model checking. We adapt the general definition of robustness introduced by Kitano to the class of stochastic systems modelled as continuous time Markov Chains in order to extensively analyse and compare robustness of biological models with uncertain parameters. The framework utilises novel computational methods that enable to effectively evaluat...
Machine Learning Methods in Statistical Model Checking and System Design – Tutorial
Bortolussi, Luca; Milios, Dimitrios; Sanguinetti, Guido
2015-01-01
Recent research has seen an increasingly fertile convergence of ideas from machine learning and formal modelling. Here we review some recently introduced methodologies for model checking and system design/parameter synthesis for logical properties against stochastic dynamical models. The crucial insight is a regularity result which states that the satisfaction probability of a logical formula is a smooth function of the parameters of a CTMC. This enables us to select an appropriate class of f...
An interval-valued reliability model with bounded failure rates
DEFF Research Database (Denmark)
Kozine, Igor; Krymsky, Victor
2012-01-01
The approach to deriving interval-valued reliability measures described in this paper is distinctive from other imprecise reliability models in that it overcomes the issue of having to impose an upper bound on time to failure. It rests on the presupposition that a constant interval-valued failure...
Cryptography in the Bounded Quantum-Storage Model
DEFF Research Database (Denmark)
Damgård, Ivan Bjerre; Serge, Fehr; Schaffner, Christian;
2008-01-01
We initiate the study of two-party cryptographic primitives with unconditional security, assuming that the adversary's quantum memory is of bounded size. We show that oblivious transfer and bit commitment can be implemented in this model using protocols where honest parties need no quantum memory...
Cryptography In The Bounded Quantum-Storage Model
DEFF Research Database (Denmark)
Damgård, Ivan Bjerre; Salvail, Louis; Schaffner, Christian;
2005-01-01
We initiate the study of two-party cryptographic primitives with unconditional security, assuming that the adversary's quantum memory is of bounded size. We show that oblivious transfer and bit commitment can be implemented in this model using protocols where honest parties need no quantum memory...
Directory of Open Access Journals (Sweden)
Ravie c. Muniyandi
2010-01-01
Full Text Available Problem statement: Membrane computing formalism has provided better modeling capabilities for biological systems in comparison to conventional mathematical models. Model checking could be used to reason about the biological system in detail and with precision by verifying formally whether membrane computing model meets the properties of the system. Approach: This study was carried to investigate the preservation of properties of two biological systems that had been modeled and simulated in membrane computing by a method of model checking using PRISM. The two biological systems were prey-predator population and signal processing in the legend-receptor networks of protein TGF-ß. Results: The model checking of membrane computing model of the biological systems with five different properties showed that the properties of the biological systems could be preserved in the membrane computing model. Conclusion: Membrane computing model not only provides a better approach in representing and simulating a biological system but also able to sustain the basic properties of the system.
Gilbert, David
2016-01-01
Insights gained from multilevel computational models of biological systems can be translated into real-life applications only if the model correctness has been verified first. One of the most frequently employed in silico techniques for computational model verification is model checking. Traditional model checking approaches only consider the evolution of numeric values, such as concentrations, over time and are appropriate for computational models of small scale systems (e.g. intracellular networks). However for gaining a systems level understanding of how biological organisms function it is essential to consider more complex large scale biological systems (e.g. organs). Verifying computational models of such systems requires capturing both how numeric values and properties of (emergent) spatial structures (e.g. area of multicellular population) change over time and across multiple levels of organization, which are not considered by existing model checking approaches. To address this limitation we have developed a novel approximate probabilistic multiscale spatio-temporal meta model checking methodology for verifying multilevel computational models relative to specifications describing the desired/expected system behaviour. The methodology is generic and supports computational models encoded using various high-level modelling formalisms because it is defined relative to time series data and not the models used to generate it. In addition, the methodology can be automatically adapted to case study specific types of spatial structures and properties using the spatio-temporal meta model checking concept. To automate the computational model verification process we have implemented the model checking approach in the software tool Mule (http://mule.modelchecking.org). Its applicability is illustrated against four systems biology computational models previously published in the literature encoding the rat cardiovascular system dynamics, the uterine contractions of labour
Trajectory based models. Evaluation of minmax pricing bounds
Degano, Ivan; Ferrando, Sebastian; Gonzalez, Alfredo
2015-01-01
The paper studies market models based on trajectory spaces, properties of such models are obtained without recourse to probabilistic assumptions. For a given European option, an interval of rational prices exists under a more general condition than the usual no-arbitrage requirement. The paper develops computational results in order to evaluate the option bounds; the global minmax optimization, defining the price interval, is reduced to a local minmax optimization via dynamic programming. A g...
Towards Support for Software Model Checking: Improving the Efficiency of Formal Specifications
Directory of Open Access Journals (Sweden)
Salamah Salamah
2011-01-01
presented in this paper provides improved LTL specifications for patterns and scopes over those originally provided by Prospec. This improvement comes in the efficiency of the LTL formulas as measured in terms of the number of states in the Büchi automaton generated for the formula. Minimizing the size of the Büchi automata for an LTL specification provides a significant improvement for model checking software systems using such tools as the highly acclaimed Spin model checker.
General bound of overfitting for MLP regression models
Rynkiewicz, Joseph
2012-01-01
Multilayer perceptrons (MLP) with one hidden layer have been used for a long time to deal with non-linear regression. However, in some task, MLP's are too powerful models and a small mean square error (MSE) may be more due to overfitting than to actual modelling. If the noise of the regression model is Gaussian, the overfitting of the model is totally determined by the behavior of the likelihood ratio test statistic (LRTS), however in numerous cases the assumption of normality of the noise is arbitrary if not false. In this paper, we present an universal bound for the overfitting of such model under weak assumptions, this bound is valid without Gaussian or identifiability assumptions. The main application of this bound is to give a hint about determining the true architecture of the MLP model when the number of data goes to infinite. As an illustration, we use this theoretical result to propose and compare effective criteria to find the true architecture of an MLP.
A Skyrme-like model with an exact BPS bound
Ferreira, L.A.; Zakrzewski, Wojtek J.
2013-01-01
We propose a new Skyrme-like model with fields taking values on the sphere S^3 or, equivalently, on the group SU(2). The action of the model contains a quadratic kinetic term plus a quartic term which is the same as that of the Skyrme-Faddeev model. The novelty of the model is that it possess a first order Bogomolny type equation whose solutions automatically satisfy the second order Euler-Lagrange equations. It also possesses a lower bound on the static energy which is saturated by the Bogom...
Generalized Skyrme model with the loosely bound potential
Gudnason, Sven Bjarke; Ma, Nana
2016-01-01
We study a generalization of the loosely bound Skyrme model which consists of the Skyrme model with a sixth-order derivative term and the second-order loosely bound potential. We use the rational map approximation for the 4-Skyrmion and calculate the binding energy and estimate the systematic error in using the latter approximation. In the parameter space that we can explore within the rational map approximation, we find classical binding energies as low as 1.8% and once taking into account the contribution from spin-isospin quantization we obtain binding energies as low as 5.3%. We also calculate the contribution from the sixth-order derivative term to the electric charge density and axial coupling.
Checking the Adequacy of Fit of Models from Split-Plot Designs
DEFF Research Database (Denmark)
Almini, A. A.; Kulahci, Murat; Montgomery, D. C.
2009-01-01
-plot models. In this article, we propose the computation of two R-2, R-2-adjusted, prediction error sums of squares (PRESS), and R-2-prediction statistics to measure the adequacy of fit for the WP and the SP submodels in a split-plot design. This is complemented with the graphical analysis of the two types...... of errors to check for any violation of the underlying assumptions and the adequacy of fit of split-plot models. Using examples, we show how computing two measures of model adequacy of fit for each split-plot design model is appropriate and useful as they reveal whether the correct WP and SP effects have...
HyLTL: a temporal logic for model checking hybrid systems
Directory of Open Access Journals (Sweden)
Davide Bresolin
2013-08-01
Full Text Available The model-checking problem for hybrid systems is a well known challenge in the scientific community. Most of the existing approaches and tools are limited to safety properties only, or operates by transforming the hybrid system to be verified into a discrete one, thus loosing information on the continuous dynamics of the system. In this paper we present a logic for specifying complex properties of hybrid systems called HyLTL, and we show how it is possible to solve the model checking problem by translating the formula into an equivalent hybrid automaton. In this way the problem is reduced to a reachability problem on hybrid automata that can be solved by using existing tools.
Holography and entropy bounds in the plane wave matrix model
Bousso, R; Bousso, Raphael; Mints, Aleksey L.
2006-01-01
As a quantum theory of gravity, Matrix theory should provide a realization of the holographic principle, in the sense that a holographic theory should contain one binary degree of freedom per Planck area. We present evidence that Bekenstein's entropy bound, which is related to area differences, is manifest in the plane wave matrix model. If holography is implemented in this way, we predict crossover behavior at strong coupling when the energy exceeds N^2 in units of the mass scale.
Higgs mass bound in the minimal standard model
Heller, U M
1993-01-01
A brief review of the role of the Higgs mechanism and the ensuing Higgs particle in the Minimal Standard Model is given. Then the property of triviality of the scalar sector in the Minimal Standard Model and the upper bound on the Higgs mass that follows is discussed. It is emphasized that the bound is obtained by limiting cutoff effects on physical processes. Actions that allow a parameterization and tuning of the leading cutoff effects are studied both analytically, in the large $N$ limit of the generalization of the $O(4)$ symmetry of the scalar sector to $O(N)$, and numerically for the physical case $N = 4$. Combining those results we show that the Minimal Standard Model will describe physics to an accuracy of a few percent up to energies of the order 2 to 4 times the Higgs mass, $M_H$, only if $M_H \\le 710 \\pm 60 ~ GeV$. This bound is the result of a systematic search in the space of dimension six operators and is expected to hold in the {\\it continuum}. (Complete postscript file can be obtained by anony...
Combination of Model Checking and Theorem Proving to Verify Embedded Software
Institute of Scientific and Technical Information of China (English)
XIAO Jian-yu; ZHANG De-yun; DONG Hao; CHEN Hai-quan
2005-01-01
In this paper, a scheme of combining model checking and theorem proving techniques to verify high trustworthy embedded software is proposed. The software model described in state machine of unified model language is transformed into the input modeling language of a model checker in which the model is analyzed with associated property specifications expressed in temporal logic. The software model which has been verified by model checker is then transformed into abstract specifications of a theorem prover , in which the model will be refined, verified and translated into source C code. The transformation rules from state machine to input language of model checker and abstract specifications of theorem prover are given. The experiment shows that the proposed scheme can effectively improve the development and verification of high trustworthy embedded software.
Visual Predictive Check in Models with Time-Varying Input Function.
Largajolli, Anna; Bertoldo, Alessandra; Campioni, Marco; Cobelli, Claudio
2015-11-01
The nonlinear mixed effects models are commonly used modeling techniques in the pharmaceutical research as they enable the characterization of the individual profiles together with the population to which the individuals belong. To ensure a correct use of them is fundamental to provide powerful diagnostic tools that are able to evaluate the predictive performance of the models. The visual predictive check (VPC) is a commonly used tool that helps the user to check by visual inspection if the model is able to reproduce the variability and the main trend of the observed data. However, the simulation from the model is not always trivial, for example, when using models with time-varying input function (IF). In this class of models, there is a potential mismatch between each set of simulated parameters and the associated individual IF which can cause an incorrect profile simulation. We introduce a refinement of the VPC by taking in consideration a correlation term (the Mahalanobis or normalized Euclidean distance) that helps the association of the correct IF with the individual set of simulated parameters. We investigate and compare its performance with the standard VPC in models of the glucose and insulin system applied on real and simulated data and in a simulated pharmacokinetic/pharmacodynamic (PK/PD) example. The newly proposed VPC performance appears to be better with respect to the standard VPC especially for the models with big variability in the IF where the probability of simulating incorrect profiles is higher. PMID:26265094
Bounding the Practical Error of Path Loss Models
Directory of Open Access Journals (Sweden)
Caleb Phillips
2012-01-01
Full Text Available We seek to provide practical lower bounds on the prediction accuracy of path loss models. We describe and implement 30 propagation models of varying popularity that have been proposed over the last 70 years. Our analysis is performed using a large corpus of measurements collected on production networks operating in the 2.4 GHz ISM, 5.8 GHz UNII, and 900 MHz ISM bands in a diverse set of rural and urban environments. We find that the landscape of path loss models is precarious: typical best-case performance accuracy of these models is on the order of 12–15 dB root mean square error (RMSE and in practice it can be much worse. Models that can be tuned with measurements and explicit data fitting approaches enable a reduction in RMSE to 8-9 dB. These bounds on modeling error appear to be relatively constant, even in differing environments and at differing frequencies. Based on our findings, we recommend the use of a few well-accepted and well-performing standard models in scenarios where a priori predictions are needed and argue for the use of well-validated, measurement-driven methods whenever possible.
Characteristics of successful opinion leaders in a bounded confidence model
Chen, Shuwei; Glass, David H.; McCartney, Mark
2016-05-01
This paper analyses the impact of competing opinion leaders on attracting followers in a social group based on a bounded confidence model in terms of four characteristics: reputation, stubbornness, appeal and extremeness. In the model, reputation differs among leaders and normal agents based on the weights assigned to them, stubbornness of leaders is reflected by their confidence towards normal agents, appeal of the leaders is represented by the confidence of followers towards them, and extremeness is captured by the opinion values of leaders. Simulations show that increasing reputation, stubbornness or extremeness makes it more difficult for the group to achieve consensus, but increasing the appeal will make it easier. The results demonstrate that successful opinion leaders should generally be less stubborn, have greater appeal and be less extreme in order to attract more followers in a competing environment. Furthermore, the number of followers can be very sensitive to small changes in these characteristics. On the other hand, reputation has a more complicated impact: higher reputation helps the leader to attract more followers when the group bound of confidence is high, but can hinder the leader from attracting followers when the group bound of confidence is low.
A variational study of bound states in the Higgs model
Siringo, F
2000-01-01
The possible existence of Higgs-Higgs bound states in the Higgs sector of the Standard Model is explored using the |hh>+|hhh> variational ansatz of Di Leo and Darewych. The resulting integral equations can be decoupled exactly, yielding a one-dimensional integral equation, solved numerically. We thereby avoid the extra approximations employed by Di Leo and Darewych, and we find a qualitatively different mass renormalization. Within the conventional scenario, where a not-too-large cutoff is invoked to avoid "triviality", we find, as usual, an upperbound on the Higgs mass. Bound-state solutions are only found in the very strong coupling regime, but at the same time a relatively small physical mass is required as a consequence of renormalization.
Modifying the pion mass in the loosely bound Skyrme model
Gudnason, Sven Bjarke
2016-01-01
We study the loosely bound Skyrme model with the addition of two different pion mass terms; this is the most general potential of polynomial form up to second order in the trace of the Skyrme field. The two pion mass terms are called the standard pion mass term and the modified pion mass term. We find that the binding energies are not reduced by the introduction of the modified pion mass, but slightly larger values of the coefficient of the loosely bound potential are allowed when the modified pion mass term is used compared to the standard pion mass term. We find by increasing the overall pion mass that we can reduce the classical binding energy of the 4-Skyrmion to the 2.7% level and the total binding energy including the contribution from spin/isospin quantization is reduced to the 5.8% level.
Model-Checking the Higher-Dimensional Modal mu-Calculus
Lange, Martin; 10.4204/EPTCS.77.6
2012-01-01
The higher-dimensional modal mu-calculus is an extension of the mu-calculus in which formulas are interpreted in tuples of states of a labeled transition system. Every property that can be expressed in this logic can be checked in polynomial time, and conversely every polynomial-time decidable problem that has a bisimulation-invariant encoding into labeled transition systems can also be defined in the higher-dimensional modal mu-calculus. We exemplify the latter connection by giving several examples of decision problems which reduce to model checking of the higher-dimensional modal mu-calculus for some fixed formulas. This way generic model checking algorithms for the logic can then be used via partial evaluation in order to obtain algorithms for theses problems which may benefit from improvements that are well-established in the field of program verification, namely on-the-fly and symbolic techniques. The aim of this work is to extend such techniques to other fields as well, here exemplarily done for process...
Bounds for perpetual American option prices in a jump diffusion model
Ekström, Erik
2006-01-01
We provide bounds for perpetual American option prices in a jump diffusion model in terms of American option prices in the standard Black-Scholes model. We also investigate the dependence of the bounds on different parameters of the model.
Sediment depositions upstream of open check dams: new elements from small scale models
Piton, Guillaume; Le Guern, Jules; Carbonari, Costanza; Recking, Alain
2015-04-01
numbers that the flows tend to adopt? New small scale model experiments have been undertaken focusing on depositions processes and their related hydraulics. Accurate photogrammetric measurements allowed us to better describe the deposition processes3. Large Scale Particle Image Velocimetry (LS-PIV) was performed to determine surface velocity fields in highly active channels with low grain submersion4. We will present preliminary results of our experiments showing the new elements we observed in massive deposit dynamics. REFERENCES 1.Armanini, A., Dellagiacoma, F. & Ferrari, L. From the check dam to the development of functional check dams. Fluvial Hydraulics of Mountain Regions 37, 331-344 (1991). 2.Piton, G. & Recking, A. Design of sediment traps with open check dams: a review, part I: hydraulic and deposition processes. (Accepted by the) Journal of Hydraulic Engineering 1-23 (2015). 3.Le Guern, J. Ms Thesis: Modélisation physique des plages de depot : analyse de la dynamique de remplissage.(2014) . 4.Carbonari, C. Ms Thesis: Small scale experiments of deposition processes occuring in sediment traps, LS-PIV measurments and geomorphological descriptions. (in preparation).
An Efficient Explicit-time Description Method for Timed Model Checking
Wang, Hao; 10.4204/EPTCS.14.6
2009-01-01
Timed model checking, the method to formally verify real-time systems, is attracting increasing attention from both the model checking community and the real-time community. Explicit-time description methods verify real-time systems using general model constructs found in standard un-timed model checkers. Lamport proposed an explicit-time description method using a clock-ticking process (Tick) to simulate the passage of time together with a group of global variables to model time requirements. Two methods, the Sync-based Explicit-time Description Method using rendezvous synchronization steps and the Semaphore-based Explicit-time Description Method using only one global variable were proposed; they both achieve better modularity than Lamport's method in modeling the real-time systems. In contrast to timed automata based model checkers like UPPAAL, explicit-time description methods can access and store the current time instant for future calculations necessary for many real-time systems, especially those with p...
Constraint LTL Satisfiability Checking without Automata
Bersani, Marcello M; Morzenti, Angelo; Pradella, Matteo; Rossi, Matteo; Pietro, Pierluigi San
2012-01-01
This paper introduces a novel technique to decide the satisfiability of formulae written in the language of Linear Temporal Logic with Both future and past operators and atomic formulae belonging to constraint system D (CLTLB(D) for short). The technique is based on the concept of bounded satisfiability, and hinges on an encoding of CLTLB(D) formulae into QF-EUD, the theory of quantifier-free equality and uninterpreted functions combined with D. Similarly to standard LTL, where bounded model-checking and SAT-solvers can be used as an alternative to automata-theoretic approaches to model-checking, our approach allows users to solve the satisfiability problem for CLTLB(D) formulae through SMT-solving techniques, rather than by checking the emptiness of the language of a suitable automaton A{\\phi}. The technique is effective, and it has been implemented in our Zot formal verification tool.
Model Checking and Code Generation for UML Diagrams Using Graph Transformation
Directory of Open Access Journals (Sweden)
Wafa Chama
2012-12-01
Full Text Available UML is considered as the standard for object-oriented modelling language adopted by the ObjectManagement Group. However, UML has been criticized due to the lack of formal semantics and theambiguity of its models. In other hands, UML models can be mathematically verified and checked by usingits equivalent formal representation. So, in this paper, we propose an approach and a tool based on graphtransformation to perform an automatic mapping for verification purposes. This transformation aims tobridge the gap between informal and formal notations and allows a formal verification of concurrent UMLmodels using Maude language. We consider both static (Class Diagram and dynamic (StateChart andCommunication Diagrams features of concurrent object-oriented system. Then, we use Maude LTL ModelChecker to verify the formal model obtained (Automatic Code Generation Maude. The meta-modellingAToM3 tool is used. A case study is presented to illustrate our approach.
Stieltjes electrostatic model interpretation for bound state problems
Indian Academy of Sciences (India)
K V S Shiv Chaitanya
2014-07-01
In this paper, it is shown that Stieltjes electrostatic model and quantum Hamilton Jacobi formalism are analogous to each other. This analogy allows the bound state problem to mimic as unit moving imaginary charges $i\\hbar$, which are placed in between the two fixed imaginary charges arising due to the classical turning points of the potential. The interaction potential between unit moving imaginary charges $i\\hbar$ is given by the logarithm of the wave function. For an exactly solvable potential, this system attains stable equilibrium position at the zeros of the orthogonal polynomials depending upon the interval of the classical turning points.
Directory of Open Access Journals (Sweden)
Christian Krause
2011-11-01
Full Text Available The assurance of quality of service properties is an important aspect of service-oriented software engineering. Notations for so-called service level agreements (SLAs, such as the Web Service Level Agreement (WSLA language, provide a formal syntax to specify such assurances in terms of (legally binding contracts between a service provider and a customer. On the other hand, formal methods for veriﬁcation of probabilistic real-time behavior have reached a level of expressiveness and efﬁciency which allows to apply them in real-world scenarios. In this paper, we suggest to employ the recently introduced model of Interval Probabilistic Timed Automata (IPTA for formal veriﬁcation of QoS properties of service-oriented systems. Speciﬁcally, we show that IPTA in contrast to Probabilistic Timed Automata (PTA are able to capture the guarantees speciﬁed in SLAs directly. A particular challenge in the analysis of IPTA is the fact that their naive semantics usually yields an inﬁnite set of states and inﬁnitely-branching transitions. However, using symbolic representations, IPTA can be analyzed rather efﬁciently. We have developed the ﬁrst implementation of an IPTA model checker by extending the PRISM tool and show that model checking IPTA is only slightly more expensive than model checking comparable PTA.
Directory of Open Access Journals (Sweden)
Marcus Völp
2012-11-01
Full Text Available Reliability in terms of functional properties from the safety-liveness spectrum is an indispensable requirement of low-level operating-system (OS code. However, with evermore complex and thus less predictable hardware, quantitative and probabilistic guarantees become more and more important. Probabilistic model checking is one technique to automatically obtain these guarantees. First experiences with the automated quantitative analysis of low-level operating-system code confirm the expectation that the naive probabilistic model checking approach rapidly reaches its limits when increasing the numbers of processes. This paper reports on our work-in-progress to tackle the state explosion problem for low-level OS-code caused by the exponential blow-up of the model size when the number of processes grows. We studied the symmetry reduction approach and carried out our experiments with a simple test-and-test-and-set lock case study as a representative example for a wide range of protocols with natural inter-process dependencies and long-run properties. We quickly see a state-space explosion for scenarios where inter-process dependencies are insignificant. However, once inter-process dependencies dominate the picture models with hundred and more processes can be constructed and analysed.
Model checking of safety-critical software in the nuclear engineering domain
International Nuclear Information System (INIS)
Instrumentation and control (I and C) systems play a vital role in the operation of safety-critical processes. Digital programmable logic controllers (PLC) enable sophisticated control tasks which sets high requirements for system validation and verification methods. Testing and simulation have an important role in the overall verification of a system but are not suitable for comprehensive evaluation because only a limited number of system behaviors can be analyzed due to time limitations. Testing is also performed too late in the development lifecycle and thus the correction of design errors is expensive. This paper discusses the role of formal methods in software development in the area of nuclear engineering. It puts forward model checking, a computer-aided formal method for verifying the correctness of a system design model, as a promising approach to system verification. The main contribution of the paper is the development of systematic methodology for modeling safety critical systems in the nuclear domain. Two case studies are reviewed, in which we have found errors that were previously not detected. We also discuss the actions that should be taken in order to increase confidence in the model checking process.
Lochbihler, Andreas
2012-01-01
The Java programming language provides safety and security guarantees such as type safety and its security architecture. They distinguish it from other mainstream programming languages like C and C++. In this work, we develop a machine-checked model of concurrent Java and the Java memory model and investigate the impact of concurrency on these guarantees. From the formal model, we automatically obtain an executable verified compiler to bytecode and a validated virtual machine.
Unitarity bound in the most general two Higgs doublet model
Directory of Open Access Journals (Sweden)
Shinya Kanemura
2015-12-01
Full Text Available We investigate unitarity bounds in the most general two Higgs doublet model without a discrete Z2 symmetry nor CP conservation. S-wave amplitudes for two-body elastic scatterings of Nambu–Goldstone bosons and physical Higgs bosons are calculated at high energies for all possible initial and final states (14 neutral, 8 singly-charged and 3 doubly-charged states. We obtain analytic formulae for the block-diagonalized scattering matrix by the classification of the two body scattering states using the conserved quantum numbers at high energies. Imposing the condition of perturbative unitarity to the eigenvalues of the scattering matrix, constraints on the model parameters can be obtained. We apply our results to constrain the mass range of the next-to-lightest Higgs state in the model.
Monitor-Based Statistical Model Checking for Weighted Metric Temporal Logic
DEFF Research Database (Denmark)
Bulychev, Petr; David, Alexandre; Larsen, Kim Guldstrand;
2012-01-01
We present a novel approach and implementation for ana- lysing weighted timed automata (WTA) with respect to the weighted metric temporal logic (WMTL≤ ). Based on a stochastic semantics of WTAs, we apply statistical model checking (SMC) to estimate and test probabilities of satisfaction with...... desired levels of confidence. Our ap- proach consists in generation of deterministic monitors for formulas in WMTL≤ , allowing for efficient SMC by run-time evaluation of a given formula. By necessity, the deterministic observers are in general approx- imate (over- or under-approximations), but are most...
Bringing Automated Model Checking to PLC Program Development - A CERN Case Study
Fernandez Adiego, B; Tournier, J-C; Blanco Vinuela, E; Gonzalez Suarez, V M
2014-01-01
Verification of critical software is a high priority but a challenging task for industrial control systems. Model checking appears to be an appropriate approach for this purpose. However, this technique is not widely used in industry yet, due to some obstacles. The main obstacles encountered when trying to apply formal verification techniques at industrial installations are the difficulty of creating models out of PLC programs and defining formally the specification requirements. In addition, models produced out of real-life programs have a huge state space, thus preventing the verification due to performance issues. Our work at CERN (European Organization for Nuclear Research) focuses on developing efficient automatic verification methods for industrial critical installations based on PLC (Programmable Logic Controller) control systems. In this paper, we present a tool generating automatically formal models out of PLC code. The tool implements a general methodology which can support several input languages, ...
Directory of Open Access Journals (Sweden)
G. Bussi
2013-08-01
Full Text Available Soil loss and sediment transport in Mediterranean areas are driven by complex non-linear processes which have been only partially understood. Distributed models can be very helpful tools for understanding the catchment-scale phenomena which lead to soil erosion and sediment transport. In this study, a modelling approach is proposed to reproduce and evaluate erosion and sediment yield processes in a Mediterranean catchment (Rambla del Poyo, Valencia, Spain. Due to the lack of sediment transport records for model calibration and validation, a detailed description of the alluvial stratigraphy infilling a check dam that drains a 12.9 km2 sub-catchment was used as indirect information of sediment yield data. These dam infill sediments showed evidences of at least 15 depositional events (floods over the time period 1990–2009. The TETIS model, a distributed conceptual hydrological and sediment model, was coupled to the Sediment Trap Efficiency for Small Ponds (STEP model for reproducing reservoir retention, and it was calibrated and validated using the sedimentation volume estimated for the depositional units associated with discrete runoff events. The results show relatively low net erosion rates compared to other Mediterranean catchments (0.136 Mg ha−1 yr−1, probably due to the extensive outcrops of limestone bedrock, thin soils and rather homogeneous vegetation cover. The simulated sediment production and transport rates offer model satisfactory results, further supported by in-site palaeohydrological evidences and spatial validation using additional check dams, showing the great potential of the presented data assimilation methodology for the quantitative analysis of sediment dynamics in ungauged Mediterranean basins.
Model Checking Artificial Intelligence Based Planners: Even the Best Laid Plans Must Be Verified
Smith, Margaret H.; Holzmann, Gerard J.; Cucullu, Gordon C., III; Smith, Benjamin D.
2005-01-01
Automated planning systems (APS) are gaining acceptance for use on NASA missions as evidenced by APS flown On missions such as Orbiter and Deep Space 1 both of which were commanded by onboard planning systems. The planning system takes high level goals and expands them onboard into a detailed of action fiat the spacecraft executes. The system must be verified to ensure that the automatically generated plans achieve the goals as expected and do not generate actions that would harm the spacecraft or mission. These systems are typically tested using empirical methods. Formal methods, such as model checking, offer exhaustive or measurable test coverage which leads to much greater confidence in correctness. This paper describes a formal method based on the SPIN model checker. This method guarantees that possible plans meet certain desirable properties. We express the input model in Promela, the language of SPIN and express the properties of desirable plans formally.
Entropy Bound for the Crystalline Vacuum Cosmic Space Model
Montemayor-Aldrete, J A; Morales-Mori, A; Mendoza-Allende, A; Cabrera-Bravo, E; Montemayor-Varela, A
2005-01-01
By applying the Heisenberg's uncertainty principle for a macroscopic quantum gas formed by gravitational waves an expression for the universal bound on the entropy proposed by Bekenstein for any system of maximum radius R and total energy E has been obtained. By using such expression, in the theoretical scheme of the crystalline vacuum cosmic model, the low entropy value at the Big Bang beginning, 1088k, is explained. According to our analysis the time arrow is well defined and the theoretical time flow occurs only in one direction as requested by the physical processes of gravitational stabilization of the vacuum space crystalline structure around equilibrium conditions. PACS numbers: 65.50.+m, 97.60.Lf, 03.65.-w, 61.50.-f, 98.80.Ft, 04.20.-q
A Skyrme-like model with an exact BPS bound
Ferreira, L. A.; Zakrzewski, Wojtek J.
2013-09-01
We propose a new Skyrme-like model with fields taking values on the sphere S 3 or, equivalently, on the group SU(2). The action of the model contains a quadratic kinetic term plus a quartic term which is the same as that of the Skyrme-Faddeev model. The novelty of the model is that it possess a first order Bogomolny type equation whose solutions automatically satisfy the second order Euler-Lagrange equations. It also possesses a lower bound on the static energy which is saturated by the Bogomolny solutions. Such Bogomolny equation is equivalent to the so-called force free equation used in plasma and solar Physics, and which possesses large classes of solutions. An old result due to Chandrasekhar prevents the existence of finite energy solutions for the force free equation on the entire three-dimensional space . We construct new exact finite energy solutions to the Bogomolny equations for the case where the space is the three-sphere S 3, using toroidal like coordinates.
A Skyrme-like model with an exact BPS bound
Ferreira, L A
2013-01-01
We propose a new Skyrme-like model with fields taking values on the sphere S^3 or, equivalently, on the group SU(2). The action of the model contains a quadratic kinetic term plus a quartic term which is the same as that of the Skyrme-Faddeev model. The novelty of the model is that it possess a first order Bogomolny type equation whose solutions automatically satisfy the second order Euler-Lagrange equations. It also possesses a lower bound on the static energy which is saturated by the Bogomolny solutions. Such Bogomolny equation is equivalent to the so-called force free equation used in plasma and solar Physics, and which possesses large classes of solutions. An old result due to Chandrasekhar prevents the existence of finite energy solutions for the force free equation on the entire tridimensional space R^3. We construct new exact finite energy solutions to the Bogomolny equations for the case where the space is the three-sphere S^3, using toroidal like coordinates.
Distance bound for nonconvex polyhedral models in close proximity
Jiménez Schlegl, Pablo; Torras, Carme
2006-01-01
In many applications, it suffices to know a lower bound on the distance between objects, instead of the exact distance itself, which may be more difficult to compute. Such an easy-to-compute lower bound on the distance between two nonconvex polyhedra is presented here, which does not require a decomposition of the original polyhedra into convex entities. Furthermore, a suitable preprocessing of the polyhedra permits lowering the effort needed to compute this lower bound, and improves its qual...
Application of a hazard-based visual predictive check to evaluate parametric hazard models.
Huh, Yeamin; Hutmacher, Matthew M
2016-02-01
Parametric models used in time to event analyses are evaluated typically by survival-based visual predictive checks (VPC). Kaplan-Meier survival curves for the observed data are compared with those estimated using model-simulated data. Because the derivative of the log of the survival curve is related to the hazard--the typical quantity modeled in parametric analysis--isolation, interpretation and correction of deficiencies in the hazard model determined by inspection of survival-based VPC's is indirect and thus more difficult. The purpose of this study is to assess the performance of nonparametric hazard estimators of hazard functions to evaluate their viability as VPC diagnostics. Histogram-based and kernel-smoothing estimators were evaluated in terms of bias of estimating the hazard for Weibull and bathtub-shape hazard scenarios. After the evaluation of bias, these nonparametric estimators were assessed as a method for VPC evaluation of the hazard model. The results showed that nonparametric hazard estimators performed reasonably at the sample sizes studied with greater bias near the boundaries (time equal to 0 and last observation) as expected. Flexible bandwidth and boundary correction methods reduced these biases. All the nonparametric estimators indicated a misfit of the Weibull model when the true hazard was a bathtub shape. Overall, hazard-based VPC plots enabled more direct interpretation of the VPC results compared to survival-based VPC plots. PMID:26563504
Taming Numbers and Durations in the Model Checking Integrated Planning System
Edelkamp, S
2011-01-01
The Model Checking Integrated Planning System (MIPS) is a temporal least commitment heuristic search planner based on a flexible object-oriented workbench architecture. Its design clearly separates explicit and symbolic directed exploration algorithms from the set of on-line and off-line computed estimates and associated data structures. MIPS has shown distinguished performance in the last two international planning competitions. In the last event the description language was extended from pure propositional planning to include numerical state variables, action durations, and plan quality objective functions. Plans were no longer sequences of actions but time-stamped schedules. As a participant of the fully automated track of the competition, MIPS has proven to be a general system; in each track and every benchmark domain it efficiently computed plans of remarkable quality. This article introduces and analyzes the most important algorithmic novelties that were necessary to tackle the new layers of expressiven...
International Nuclear Information System (INIS)
For those who run an organization, it is critical to identify the causal relationship between the organization's characteristics and the safety-checking action of its staff, in order to effectively implement activities for promoting safety. In this research. a causal model of the safety-checking action was developed and factors affecting it were studied. A questionnaire survey, which includes safety awareness, attitude toward safety, safety culture and others, was conducted at three nuclear power plants and eight factors were extracted by means of factor analysis of the questionnaire items. The extracted eight interrelated factors were as follows: work norm, supervisory action, interest in training, recognition of importance, safety-checking action, the subject of safety, knowledge/skills, and the attitude of an organization. Among them, seven factors except the recognition of importance were defined as latent variables and a causal model of safety-checking action was constructed. By means of covariance structure analysis, it was found that the three factors: the attitude of an organization, supervisory action and the subject of safety, have a significant effect on the safety-checking action. Moreover, it was also studied that workplaces in which these three factors are highly regarded form social environment where safety-checking action is fully supported by the workplace as a whole, while workplaces in which these three factors are poorly regarded do not fully form social environment where safety-checking action is supported. Therefore, the workplaces form an organizational environment where safety-checking action tends to depend strongly upon the knowledge or skills of individuals. On top of these, it was noted that the attitude of an organization and supervisory action are important factors that serve as the first trigger affecting the formation of the organizational climate for safety. (author)
International Nuclear Information System (INIS)
The work of Krommes and Smith on rigorous upper bounds for the turbulent transport of a passively advected scalar [/ital Ann. Phys./ 177:246 (1987)] is extended in two directions: (1) For their ''reference model,'' improved upper bounds are obtained by utilizing more sophisticated two-time constraints which include the effects of cross-correlations up to fourth order. Numerical solutions of the model stochastic differential equation are also obtained; they show that the new bounds compare quite favorably with the exact results, even at large Reynolds and Kubo numbers. (2) The theory is extended to take account of a finite spatial autocorrelation length L/sub c/. As a reasonably generic example, the problem of particle transport due to statistically specified stochastic magnetic fields in a collisionless turbulent plasma is revisited. A bound is obtained which reduces for small L/sub c/ to the quasilinear limit and for large L/sub c/ to the strong turbulence limit, and which provides a reasonable and rigorous interpolation for intermediate values of L/sub c/. 18 refs., 6 figs
WAVE EQUATION MODEL FOR SHIP WAVES IN BOUNDED SHALLOW WATER
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
Ships were modelled as moving pressure disturbances on the free surface of a shallow water basin in the present paper.The moving-pressure generating waves were subjected to the reflection of land boundaries and the radiation of open boundaries.This paper proposed and examined a wave equation model (WEM) to solve the shallow water equations with moving surface pressures simulating ship waves in a bounded shallow water region.The Galerkin finite element method was used to solve a second order wave equation for the free surface elevations and the hydrodynamic pressure of the ship bottom simultaneously.Horizontal velocities were obtained from the momentum equations.Numerical solutions of Series 60 CB=0.6 ships moving with the depth Froude number of Fh=0.6, 1.0, 1.3 in a rectangular shallow water harbor were investigated.Three dimensional surface elevation profiles and the depth-averaged horizontal velocities were analysed.The numerical results characterised very well the ship waves in shallow water.Strong boundary reflection waves were found in the case of high depth Froude number (Fh=1.3).Waves generated by the interactions of two ships moving in the same directions and in the opposite directions were also numerically investigated in the present study.
Perturbative Unitarity Bounds in Composite 2-Higgs Doublet Models
De Curtis, Stefania; Yagyu, Kei; Yildirim, Emine
2016-01-01
We study bounds from perturbative unitarity in a Composite 2-Higgs Doublet Model (C2HDM) based on the spontaneous breakdown of a global symmetry $SO(6)\\to SO(4)\\times SO(2)$ at the compositeness scale $f$. The eight pseudo Nambu-Goldstone Bosons (pNGBs) emerging from such a dynamics are identified as two isospin doublet Higgs fields. We calculate the $S$-wave amplitude for all possible 2-to-2-body elastic (pseudo)scalar boson scatterings at energy scales $\\sqrt{s}$ reachable at the Large Hadron Collider (LHC) and beyond it, including the longitudinal components of weak gauge boson states as the corresponding pNGB states. In our calculation, the Higgs potential is assumed to have the same form as that in the Elementary 2-Higgs Doublet Model (E2HDM) with a discrete $Z_2$ symmetry, which is expected to be generated at the one-loop level via the Coleman-Weinberg (CW) mechanism. We find that the $S$-wave amplitude matrix can be block-diagonalized with maximally $2\\times 2$ submatrices in a way similar to the E2HDM...
Pricing bounds for discrete arithmetic Asian options under Lévy models
Lemmens, D.; Liang, L. Z. J.; Tempere, J.; De Schepper, A.
2010-11-01
Analytical bounds for Asian options are almost exclusively available in the Black-Scholes framework. In this paper we derive bounds for the price of a discretely monitored arithmetic Asian option when the underlying asset follows an arbitrary Lévy process. Explicit formulas are given for Kou’s model, Merton’s model, the normal inverse Gaussian model, the CGMY model and the variance gamma model. The results are compared with the comonotonic upper bound, existing numerical results, Monte carlo simulations and in the case of the variance gamma model with an existing lower bound. The method outlined here provides lower and upper bounds that are quick to evaluate, and more accurate than existing bounds.
Extended FRAM by Integrating with Model Checking to Effectively Explore Hazard Evolution
Directory of Open Access Journals (Sweden)
Guihuan Duan
2015-01-01
Full Text Available Functional Resonance Analysis Method (FRAM, which defines a systemic framework to model complex systems from the perspective of function and views accidents as emergent phenomenon of function’s variability, is playing an increasingly significant role in the development of systemic accident theory. However, as FRAM is typically taken as a theoretic method, there is a lack of specific approaches or supportive tools to bridge the theory and practice. To fill the gap and contribute to the development of FRAM, (1 function’s variability was described further, with the rules of interaction among variability of different functions being determined and (2 the technology of model checking (MC was used for the analysis of function’s variability to automatically search the potential paths that could lead to hazards. By means of MC, system’s behaviors (normal or abnormal are simulated and the counter example(s that violates the safety constraints and requirements can be provided, if there is any, to improve the system design. The extended FRAM approach was applied to a typical air accident analysis, with more details drawn than the conclusions in the accident report issued officially by Agenzia Nazionale per la Sicurezza del Volo (ANSV.
International Nuclear Information System (INIS)
A check valve for use in a GDCS of a nuclear reactor and having a motor driven disk including a rotatable armature for rotating the check valve disk over its entire range of motion is described. In one embodiment, the check valve includes a valve body having a coolant flow channel extending therethrough. The coolant flow channel includes an inlet end and an outlet end. A valve body seat is located on an inner surface of the valve body. The check valve further includes a disk assembly, sometimes referred to as the motor driven disc, having a counterweight and a disk shaped valve. The disk valve includes a disk base having a seat for seating with the valve body seat. The disk assembly further includes a first hinge pin member which extends at least partially through the disk assembly and is engaged to the disk. The disk valve is rotatable relative to the first hinge pin member. The check valve also includes a motor having a stator frame with a stator bore therein. An armature is rotatably positioned within the stator bore and the armature is coupled to the disk valve to cause the disk valve to rotate about its full range of motion. 5 figs
New perspective in statistical modeling of wall-bounded turbulence
She, Zhen-Su; Chen, Xi; Wu, You; Hussain, Fazle
2010-12-01
Despite dedicated effort for many decades, statistical description of highly technologically important wall turbulence remains a great challenge. Current models are unfortunately incomplete, or empirical, or qualitative. After a review of the existing theories of wall turbulence, we present a new framework, called the structure ensemble dynamics (SED), which aims at integrating the turbulence dynamics into a quantitative description of the mean flow. The SED theory naturally evolves from a statistical physics understanding of non-equilibrium open systems, such as fluid turbulence, for which mean quantities are intimately coupled with the fluctuation dynamics. Starting from the ensemble-averaged Navier-Stokes (EANS) equations, the theory postulates the existence of a finite number of statistical states yielding a multi-layer picture for wall turbulence. Then, it uses order functions (ratios of terms in the mean momentum as well as energy equations) to characterize the states and transitions between states. Application of the SED analysis to an incompressible channel flow and a compressible turbulent boundary layer shows that the order functions successfully reveal the multi-layer structure for wall-bounded turbulence, which arises as a quantitative extension of the traditional view in terms of sub-layer, buffer layer, log layer and wake. Furthermore, an idea of using a set of hyperbolic functions for modeling transitions between layers is proposed for a quantitative model of order functions across the entire flow domain. We conclude that the SED provides a theoretical framework for expressing the yet-unknown effects of fluctuation structures on the mean quantities, and offers new methods to analyze experimental and simulation data. Combined with asymptotic analysis, it also offers a way to evaluate convergence of simulations. The SED approach successfully describes the dynamics at both momentum and energy levels, in contrast with all prevalent approaches describing
Two-vibron bound states in the β-Fermi-Pasta-Ulam model
Institute of Scientific and Technical Information of China (English)
Hu Xin-Guang; Tang Yi
2008-01-01
This paper studies the two-vibron bound states in the β-Fermi-Pasta-Ulam model by means of the number conserving approximation combined with the number state method.The results indicate that on-site,adjacent-site and mixed two-vibron bound states may exist in the model.Specially,wave number has a significant effect on such bound states,which may be considered as the quantum effects of the localized states in quantum systems.
Hussain, Faraz; Jha, Sumit K.; Jha, Susmit; Langmead, Christopher J.
2014-01-01
Stochastic models are increasingly used to study the behaviour of biochemical systems. While the structure of such models is often readily available from first principles, unknown quantitative features of the model are incorporated into the model as parameters. Algorithmic discovery of parameter values from experimentally observed facts remains a challenge for the computational systems biology community. We present a new parameter discovery algorithm that uses simulated annealing, sequential ...
DEFF Research Database (Denmark)
Vester, Steen
We study the complexity of the model-checking problem for the branching-time logic CTL ∗ and the alternating-time temporal logics ATL/ATL ∗ in one-counter processes and one-counter games respectively. The complexity is determined for all three logics when integer weights are input in unary (non...
K-nuclear bound states in a dynamical model
Czech Academy of Sciences Publication Activity Database
Mareš, Jiří; Friedman, E.; Gal, A.
2006-01-01
Roč. 770, 1/2 (2006), s. 84-105. ISSN 0375-9474 Institutional research plan: CEZ:AV0Z10480505 Keywords : kaonic atoms * K-nuclear bound states * K-nucleus interaction Subject RIV: BE - Theoretical Physics Impact factor: 2.155, year: 2006
Improved shape hardening function for bounding surface model for cohesive soils
Directory of Open Access Journals (Sweden)
Andrés Nieto-Leal
2014-08-01
Full Text Available A shape hardening function is developed that improves the predictive capabilities of the generalized bounding surface model for cohesive soils, especially when applied to overconsolidated specimens. This improvement is realized without any changes to the simple elliptical shape of the bounding surface, and actually reduces the number of parameters associated with the model by one.
Skyrmion model in 2+1 dimensions with soliton bound states
Energy Technology Data Exchange (ETDEWEB)
Piette, B.; Zakrzewski, W.J. (Dept. of Mathematical Sciences, Univ. Durham (United Kingdom))
1993-03-22
We consider a class of skyrmion models in 2+1 dimensions which possess bound stable solitons. We show that these models have one-soliton solutions as well as static solutions corresponding to their bound states. We study the scattering and stability properties of these solutions, compute their energies and estimate their binding energies. (orig.).
Automated parameter estimation for biological models using Bayesian statistical model checking
Hussain, Faraz; Langmead, Christopher J.; Mi, Qi; Dutta-Moscato, Joyeeta; Vodovotz, Yoram; Jha, Sumit K.
2015-01-01
Background Probabilistic models have gained widespread acceptance in the systems biology community as a useful way to represent complex biological systems. Such models are developed using existing knowledge of the structure and dynamics of the system, experimental observations, and inferences drawn from statistical analysis of empirical data. A key bottleneck in building such models is that some system variables cannot be measured experimentally. These variables are incorporated into the mode...
Dependence in probabilistic modeling, Dempster-Shafer theory, and probability bounds analysis.
Energy Technology Data Exchange (ETDEWEB)
Oberkampf, William Louis; Tucker, W. Troy (Applied Biomathematics, Setauket, NY); Zhang, Jianzhong (Iowa State University, Ames, IA); Ginzburg, Lev (Applied Biomathematics, Setauket, NY); Berleant, Daniel J. (Iowa State University, Ames, IA); Ferson, Scott (Applied Biomathematics, Setauket, NY); Hajagos, Janos (Applied Biomathematics, Setauket, NY); Nelsen, Roger B. (Lewis & Clark College, Portland, OR)
2004-10-01
This report summarizes methods to incorporate information (or lack of information) about inter-variable dependence into risk assessments that use Dempster-Shafer theory or probability bounds analysis to address epistemic and aleatory uncertainty. The report reviews techniques for simulating correlated variates for a given correlation measure and dependence model, computation of bounds on distribution functions under a specified dependence model, formulation of parametric and empirical dependence models, and bounding approaches that can be used when information about the intervariable dependence is incomplete. The report also reviews several of the most pervasive and dangerous myths among risk analysts about dependence in probabilistic models.
Evading Lyth bound in models of quintessential inflation
International Nuclear Information System (INIS)
Quintessential inflation refers to an attempt to unify inflation and late-time cosmic acceleration using a single scalar field. In this letter we consider two different classes of quintessential inflation, one of which is based upon a Lagrangian with non-canonical kinetic term k2(ϕ)∂μϕ∂μϕ and a steep exponential potential while the second class uses the concept of steep brane world inflation. We show that in both cases the Lyth bound can be evaded, despite the large tensor-to-scalar ratio of perturbations. The post-inflationary dynamics is consistent with nucleosynthesis constraint in these cases
Mixed and Mixture Regression Models for Continuous Bounded Responses Using the Beta Distribution
Verkuilen, Jay; Smithson, Michael
2012-01-01
Doubly bounded continuous data are common in the social and behavioral sciences. Examples include judged probabilities, confidence ratings, derived proportions such as percent time on task, and bounded scale scores. Dependent variables of this kind are often difficult to analyze using normal theory models because their distributions may be quite…
Model of bound interface dynamics for coupled magnetic domain walls
Politi, P.; Metaxas, P. J.; Jamet, J.-P.; Stamps, R. L.; Ferré, J.
2011-08-01
A domain wall in a ferromagnetic system will move under the action of an external magnetic field. Ultrathin Co layers sandwiched between Pt have been shown to be a suitable experimental realization of a weakly disordered 2D medium in which to study the dynamics of 1D interfaces (magnetic domain walls). The behavior of these systems is encapsulated in the velocity-field response v(H) of the domain walls. In a recent paper [P. J. Metaxas , Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.104.237206 104, 237206 (2010)] we studied the effect of ferromagnetic coupling between two such ultrathin layers, each exhibiting different v(H) characteristics. The main result was the existence of bound states over finite-width field ranges, wherein walls in the two layers moved together at the same speed. Here we discuss in detail the theory of domain wall dynamics in coupled systems. In particular, we show that a bound creep state is expected for vanishing H and we give the analytical, parameter free expression for its velocity which agrees well with experimental results.
Gluino bounds: Simplified Models vs a Particular SO(10) Model (A Snowmass white paper)
Anandakrishnan, Archana; Raby, Stuart; Wingerter, Akin
2013-01-01
We consider the results from the first run of LHC studied in the context of simplified models and re-interpret them for a particular SO(10) model with a non-simplified topology. Hadronic searches have been designed to obtain the best sensitivity for the simplified models. They require multiple b-jets in the final state. But we show that the bounds obtained from these searches are weaker in the case of the particular model studied here, since there are fewer b-jets.
Relevance of the ICRP biokinetic model for dietary organically bound tritium
International Nuclear Information System (INIS)
Ingested dietary tritium can participate in metabolic processes, and become synthesized into organically bound tritium in the tissues and organs. The distribution and retention of the organically bound tritium throughout the body are much different than tritium in the body water. The International Commission on Radiological Protection (ICRP) Publication 56 (1989) has a biokinetic model to calculate dose from the ingestion of organically bound dietary tritium. The model predicts that the dose from the ingestion of organically bound dietary tritium is about 2.3 times higher than from the ingestion of the same activity of tritiated water. Under steady-state conditions, the calculated dose rate (using the first principle approach) from the ingestion of dietary organically bound tritium can be twice that from the ingestion of tritiated water. For an adult, the upper-bound dose estimate for the ingestion of dietary organically bound tritium is estimated to be close to 2.3 times higher than that of tritiated water. Therefore, given the uncertainty in the dose calculation with respect to the actual relevant dose, the ICRP biokinetic model for organically bound tritium is sufficient for dosimetry for adults. (author)
Electrostatic self-energy and Bekenstein entropy bound in the massive Schwinger model
Sadjadi, H M
2005-01-01
We obtain the electrostatic energy of two opposite charges near the horizon of stationary black-holes in the massive Schwinger model. Besides the confining aspects of the model, we discuss the Bekenstein entropy upper bound of a charged object using the generalized second law. We show that despite the massless case, in the massive Schwinger model the entropy of the black hole and consequently the Bekenstein bound are altered by the vacuum polarization.
A heterogeneous boundedly rational expectation model for housing market
Institute of Scientific and Technical Information of China (English)
Andrew Y. T. LEUNG; Jia-na XU; Wing Shum TSUI
2009-01-01
This research aims to test the housing price dynamics when considering heterogeneous boundedly rational expectations such as naive expectation, adaptive expectation and biased belief. The housing market is investigated as an evolutionary system with heterogeneous and competing expectations. The results show that the dynamics of the expected housing price varies substantially when heterogeneous expectations are considered together with some other endogenous factors. Simulation results explain some stylized phenomena such as equilibrium or oscillation, convergence or divergence, and over-shooting or under-shooting. Furthermore, the results suggest that variation of the proportion of groups of agents is basically dependent on the selected strategies. It also indicates that control policies should be chosen carefully in consistence with a unique real estate market during a unique period since certain parameter portfolio may increase or suppress oscillation.
A practical approach to model checking Duration Calculus using Presburger Arithmetic
DEFF Research Database (Denmark)
Hansen, Michael Reichhardt; Dung, Phan Anh; Brekling, Aske Wiid
upper bound. The generated Presburger formulas have a rich Boolean structure, many quantifiers and quantifier alternations. Such formulas are simplified using so-called guarded formulas, where a guard provides a context used to simplify the rest of the formula. A normal form for guarded formulas...
Tools for model-independent bounds in direct dark matter searches
Del Nobile, Eugenio; Panci, Paolo
2013-01-01
We discuss a framework (based on non-relativistic operators) and a self-contained set of numerical tools to derive the bounds from some current direct detection experiments on any arbitrary model of Dark Matter.
Upper Higgs boson mass bounds from a chirally invariant lattice Higgs-Yukawa Model
Energy Technology Data Exchange (ETDEWEB)
Gerhold, P. [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; John von Neumann-Institut fuer Computing NIC/DESY, Zeuthen (Germany); Jansen, K. [John von Neumann-Institut fuer Computing NIC/DESY, Zeuthen (Germany)
2010-02-15
We establish the cutoff-dependent upper Higgs boson mass bound by means of direct lattice computations in the framework of a chirally invariant lattice Higgs-Yukawa model emulating the same chiral Yukawa coupling structure as in the Higgs-fermion sector of the Standard Model. As expected from the triviality picture of the Higgs sector, we observe the upper mass bound to decrease with rising cutoff parameter {lambda}. Moreover, the strength of the fermionic contribution to the upper mass bound is explored by comparing to the corresponding analysis in the pure {phi}{sup 4}-theory. (orig.)
Brustein, Ram
2000-01-01
The identification of a causal-connection scale motivates us to propose a new covariant bound on entropy within a generic space-like region. This "causal entropy bound", scaling as the square root of EV, and thus lying around the geometric mean of Bekenstein's S/ER and holographic S/A bounds, is checked in various "critical" situations. In the case of limited gravity, Bekenstein's bound is the strongest while naive holography is the weakest. In the case of strong gravity, our bound and Bousso's holographic bound are stronger than Bekenstein's, while naive holography is too tight, and hence typically wrong.
Tools for model-independent bounds in direct dark matter searches
DEFF Research Database (Denmark)
Cirelli, M.; Del Nobile, E.; Panci, P.
2013-01-01
We discuss a framework (based on non-relativistic operators) and a self-contained set of numerical tools to derive the bounds from some current direct detection experiments on virtually any arbitrary model of Dark Matter elastically scattering on nuclei.......We discuss a framework (based on non-relativistic operators) and a self-contained set of numerical tools to derive the bounds from some current direct detection experiments on virtually any arbitrary model of Dark Matter elastically scattering on nuclei....
The effect of η-η' mixing in the bound state version of the Skyrme model
International Nuclear Information System (INIS)
The η-η' mixing is incorporated in the symmetry breaking term in the extended Skyrme model Lagrangian. Besides η-soliton bound states, an s-wave and a p-wave η'-soliton bound states are found. After fixing the value of the strength parameter X of the ''alternative term'' to fit the s-wave η'-soliton bound state to the N(1535) negative-parity nucleon resonance, the η-soliton bound states disappear. Then only η'-soliton bound states are identified with nucleon resonances (I=1/2) and delta resonances (I=3/2). The predicted resonance masses agree well with experimental values. The decay widths ΓN*→N+η of the relevant nucleon resonances are also calculated to explain why these particles have large branching ratios in the ηN channel. (orig.)
Model checking of time Petri nets using the state class timed automaton
DEFF Research Database (Denmark)
Lime, Didier; Roux, Olivier H.
2006-01-01
behavioral semantics of the TPN (the initial TPN and the obtained TA are proved timed-bisimilar). It allows us to check real-time properties on TPN by using the state class TA. This can be done efficiently thanks to a reduction of the number of clocks. We have implemented the method, and give some...... experimental results illustrating the efficiency of the translation algorithm in terms of number of clocks. Using the state class TA, we also give a framework for expressing and efficiently verifying TCTL properties on the initial TPN....
General bound of overfitting for MLP regression models
Rynkiewicz, Joseph
2012-01-01
Multilayer perceptrons (MLP) with one hidden layer have been used for a long time to deal with non-linear regression. However, in some task, MLP's are too powerful models and a small mean square error (MSE) may be more due to overfitting than to actual modelling. If the noise of the regression model is Gaussian, the overfitting of the model is totally determined by the behavior of the likelihood ratio test statistic (LRTS), however in numerous cases the assumption of normality of the noise is...
Computational and Game-Theoretic Approaches for Modeling Bounded Rationality
L. Waltman (Ludo)
2011-01-01
textabstractThis thesis studies various computational and game-theoretic approaches to economic modeling. Unlike traditional approaches to economic modeling, the approaches studied in this thesis do not rely on the assumption that economic agents behave in a fully rational way. Instead, economic age
Directory of Open Access Journals (Sweden)
Katie Ovens
2012-01-01
Full Text Available Introduction: Delta checks use two specimen test results taken in succession in order to detect test result changes greater than expected physiological variation. One of the most common and serious errors detected by delta checks is specimen mix-up errors. The positive and negative predictive values of delta checks for detecting specimen mix-up errors, however, are largely unknown. Materials and Methods: We addressed this question by first constructing a stochastic dynamic model using repeat test values for five analytes from approximately 8000 inpatients in Calgary, Alberta, Canada. The analytes examined were sodium, potassium, chloride, bicarbonate, and creatinine. The model simulated specimen mix-up errors by randomly switching a set number of pairs of second test results. Sensitivities and specificities were then calculated for each analyte for six combinations of delta check equations and cut-off values from the published literature. Results: Delta check specificities obtained from this model ranged from 50% to 99%; however the sensitivities were generally below 20% with the exception of creatinine for which the best performing delta check had a sensitivity of 82.8%. Within a plausible incidence range of specimen mix-ups the positive predictive values of even the best performing delta check equation and analyte became negligible. Conclusion: This finding casts doubt on the ongoing clinical utility of delta checks in the setting of low rates of specimen mix-ups.
DEFF Research Database (Denmark)
Odgaard, Peter Fogh; Stoustrup, Jakob; Mataji, B.
2007-01-01
of the prediction error. These proposed dynamical uncertainty models result in an upper and lower bound on the predicted performance of the plant. The dynamical uncertainty models are used to estimate the uncertainty of the predicted performance of a coal-fired power plant. The proposed scheme, which uses dynamical......Predicting the performance of large scale plants can be difficult due to model uncertainties etc, meaning that one can be almost certain that the prediction will diverge from the plant performance with time. In this paper output multiplicative uncertainty models are used as dynamical models...... models, is applied to two different sets of measured plant data. The computed uncertainty bounds cover the measured plant output, while the nominal prediction is outside these uncertainty bounds for some samples in these examples. ...
Two-polariton bound states in the Jaynes-Cummings-Hubbard model
International Nuclear Information System (INIS)
We examine the eigenstates of the one-dimensional Jaynes-Cummings-Hubbard model in the two-excitation subspace. We discover that two-excitation bound states emerge when the ratio of vacuum Rabi frequency to the tunneling rate between cavities exceeds a critical value. We determine the critical value as a function of the quasimomentum quantum number, and indicate that the bound states carry a strong correlation in which the two polaritons appear to be spatially confined together.
Surface-bounded growth modeling applied to human mandibles
DEFF Research Database (Denmark)
Andresen, Per Rønsholt
1999-01-01
pointing more upward. The full dataset consists of 31 mandibles from six patients. Each patient is longitudinally CT scanned between three and seven times. Age range is 1 month to 12 years old for the scans. Growth modeling consists of three overall steps: 1.extraction of features. 2.registration of the...... old mandible based on the 3 month old scan. When using successively more recent scans as basis for the model the error drops to 2.0 mm for the 11 years old scan. Thus, it seems reasonable to assume that the mandibular growth is linear.......This thesis presents mathematical and computational techniques for three dimensional growth modeling applied to human mandibles. The longitudinal shape changes make the mandible a complex bone. The teeth erupt and the condylar processes change direction, from pointing predominantly backward to...
Composite models of hadrons and relativistic bound states
International Nuclear Information System (INIS)
The following problems are considered: what the constituents of the hadrons are; what their quantum numbers and their broken and unbroken symmetries are; what the dynamics of the constituents (equations, binding forces and the origin of symmetry violations) is. The most puzzling question is: why the constituents ''escape from freedom'' and are confined inside the hadrons; what experimentalists can report about the hadron constituents and their dynamics if not finding them. There are no final answers to all these questions. The achievements of quark model are described, some problems concerning the comparison of the quark model with experiment are considered. The attempt is also made to present alternative views on the same problems
Hong, Sungwook E.; Park, Changbom; Kim, Juhan
2016-01-01
We develop a galaxy assignment scheme that populates dark matter halos with galaxies by tracing the most bound member particles (MBPs) of simulated halos. Several merger-timescale models based on analytic calculations and numerical simulations are adopted as the survival time of mock satellite galaxies. We build mock galaxy samples from halo merger data of the Horizon Run 4 $N$-body simulation from $z = 12-0$. We compare group properties and two-point correlation functions (2pCFs) of mock gal...
Directory of Open Access Journals (Sweden)
Cătălin Dima
2010-06-01
Full Text Available We present a variant of ATL with distributed knowledge operators based on a synchronous and perfect recall semantics. The coalition modalities in this logic are based on partial observation of the full history, and incorporate a form of cooperation between members of the coalition in which agents issue their actions based on the distributed knowledge, for that coalition, of the system history. We show that model-checking is decidable for this logic. The technique utilizes two variants of games with imperfect information and partially observable objectives, as well as a subset construction for identifying states whose histories are indistinguishable to the considered coalition.
Dimer model for Tau proteins bound in microtubule bundles
Hall, Natalie; Kluber, Alexander; Hayre, N. Robert; Singh, Rajiv; Cox, Daniel
2013-03-01
The microtubule associated protein tau is important in nucleating and maintaining microtubule spacing and structure in neuronal axons. Modification of tau is implicated as a later stage process in Alzheimer's disease, but little is known about the structure of tau in microtubule bundles. We present preliminary work on a proposed model for tau dimers in microtubule bundles (dimers are the minimal units since there is one microtubule binding domain per tau). First, a model of tau monomer was created and its characteristics explored using implicit solvent molecular dynamics simulation. Multiple simulations yield a partially collapsed form with separate positively/negatively charged clumps, but which are a factor of two smaller than required by observed microtubule spacing. We argue that this will elongate in dimer form to lower electrostatic energy at a cost of entropic ``spring'' energy. We will present preliminary results on steered molecular dynamics runs on tau dimers to estimate the actual force constant. Supported by US NSF Grant DMR 1207624.
Physical modelling of sediment transport in mountain torrents upstream of open check dams
Schwindt, Sebastian; Franca, Mario J.; Schleiss, Anton J.
2015-04-01
Dynamic morphological processes in mountain torrents do not only attract the attention of many contemporary researchers, but are also a relevant issue for the design of flood protection measures in the downstream sections where dwellers may be threatened by the important potential of flows with high concentration of sediments. Events which have a morphodynamic effect are simulated at the Laboratory of Hydraulic Constructions (LCH) in order to optimize the design of a flood protection measure, notably open check dams. Different scenarios with a fix bed consisting of boulders as well as mobile beds are studied and the influence of flow constrictions, i.e. distinct geometric configurations of open check dams are analysed. Three varying water pumped discharges in the order of 5 to 20 l/s are tested with progressively increasing solid discharges of 1, 3 and 6 % of the liquid discharge according to the transport capacity. The moistened sediments are introduced via a system of conveyor belts and are then mixed with the liquid discharge in an about 3 m long rough trapezoidal channel with a base width of 24 cm. The mean diameter Dm of the injected sediments is 0.86 cm and the dimensionless grain size distribution is in line with a normalized shape derived from over 60 streams in the Alps. A wide range of frequent floods in morphologically diverging types of mountain torrents is covered, in particular regarding the sediment availability in the catchment area and along the river. A basic assumption here is considering that the frequent floods are floods with return periods between 1 to 5 years and are the most important process in terms of amounts of sediment transport. This may be arguable for some mountain torrents and landscape effective processes which are driven by floods with return periods of more than several decades. In order to identify benchmarks for hydraulic parameters which lead to the obstruction of flow restrictions at mountain torrents, the water depth is
Upper Bound on the Gluino Mass in Supersymmetric Models with Extra Matters
Moroi, Takeo; Yokozaki, Norimi
2016-01-01
We discuss the upper bound on the gluino mass in supersymmetric models with vector-like extra matters. In order to realize the observed Higgs mass of 125 GeV, the gluino mass is bounded from above in supersymmetric models. With the existence of the vector-like extra matters at around TeV, we show that such an upper bound on the gluino mass is significantly reduced compared to the case of minimal supersymmetric standard model. This is due to the fact that radiatively generated stop masses as well the stop trilinear coupling are enhanced in the presence of the vector-like multiplets. In a wide range of parameter space of the model with extra matters, the gluino is required to be lighter than $\\sim 3$ TeV, which is likely to be within the reach of forthcoming LHC experiment.
QQqq Four-Quark Bound States in Chiral SU(3) Quark Model
Institute of Scientific and Technical Information of China (English)
ZHANG Ming; ZHANG Hai-Xia; ZHANG Zong-Ye
2008-01-01
The possibility of QQqq heavy-light four-quark bound states has been analyzed by means of the chiral SU(3) quark model, where Q is the heavy quark (c or b) and q is the light quark (u, d, or s). We obtain a bound state for the bbnn configuration with quantum number JP=1+, I=0 and for the ccnn (JP=1+, I=0) configuration, which is not bound but slightly above the D*D* threshold (n is u or d quark). Meanwhile, we also conclude that a weakly bound state in bbnn system can also be found without considering the chiral quark interactions between the two light quarks, yet its binding energy is weaker than that with the chiral quark interactions.
Brustein, R; Veneziano, G
1999-01-01
The identification of a causal-connection scale motivates us to propose a new covariant bound on entropy within a generic space-like region. This "causal entropy bound", scaling as the square root of EV, and thus lying around the geometric mean of Bekenstein's S/ER and holographic S/A bounds, is checked in various "critical" situations. In the case of limited gravity, Bekenstein's bound is the strongest while naive holography is the weakest. In the case of strong gravity, our bound and Bousso...
Song, Yunquan; Lin, Lu; Jian, Ling
2016-07-01
Single-index varying-coefficient model is an important mathematical modeling method to model nonlinear phenomena in science and engineering. In this paper, we develop a variable selection method for high-dimensional single-index varying-coefficient models using a shrinkage idea. The proposed procedure can simultaneously select significant nonparametric components and parametric components. Under defined regularity conditions, with appropriate selection of tuning parameters, the consistency of the variable selection procedure and the oracle property of the estimators are established. Moreover, due to the robustness of the check loss function to outliers in the finite samples, our proposed variable selection method is more robust than the ones based on the least squares criterion. Finally, the method is illustrated with numerical simulations.
Transverse momentum bounds and scaling in the hydrodynamical model
Chaichian, Masud; Suhonen, E
1974-01-01
It is shown that the equation of state of an ideal relativistic gas, as applied in the hydrodynamical model, leads not only to deviations from scaling in longitudinal rapidity distributions, but also to an average transverse momentum increasing asymptotically as a power of the incident energy. To prevent such an increase, one must use the equation of state of an interacting gas, in which the velocity of sound becomes asymptotically equal to that of light. This then also restores scaling (up to logarithmic terms) in longitudinal rapidity. (25 refs).
International Nuclear Information System (INIS)
Numerical valve models for simulation of selfactuating safety valves and damped check valves are introduced for the computer programs TRAC-PF1 and ROLAST. As examples of application post-test calculations and stability analysis are given. (orig.)
Gutiérrez-Rodríguez, A
2003-01-01
A bound on the nu /sup tau / magnetic moment is calculated through the reaction e/sup +/e/sup -/ to nu nu gamma at the Z/sub 1/-pole, and in the framework of a left-right symmetric model at LEP energies. We find that the bound is almost independent of the mixing angle phi of the model in the allowed experimental range for this parameter. (31 refs).
Hong, Sungwook E; Kim, Juhan
2016-01-01
We develop a galaxy assignment scheme that populates dark matter halos with galaxies by tracing the most bound member particles (MBPs) of simulated halos. Several merger-timescale models based on analytic calculations and numerical simulations are adopted as the survival time of mock satellite galaxies. We build mock galaxy samples from halo merger data of the Horizon Run 4 $N$-body simulation from $z = 12-0$. We compare group properties and two-point correlation functions (2pCFs) of mock galaxies with those of volume-limited SDSS galaxies, with $r$-band absolute magnitudes of $\\mathcal{M}_r - 5 \\log h 10^{14} h^{-1} M_{\\odot}$) and the small-scale 2pCF ($r_{\\rm p} < 10 h^{-1} {\\rm Mpc}$) quite well for the majority of the merger timescale models adopted. The new scheme outperforms the previous subhalo-galaxy correspondence scheme by more than $2\\sigma$.
Two-phase bounded acceleration traffic flow model: Analytical solutions and applications
LEBACQUE, JP
2003-01-01
The present paper describes a two phase traffic flow model. One phase is traffic equilibrium: flow and speed are functions of density, and traffic acceleration is low. The second phase is characterized by constant acceleration. This model extends first order traffic flow models and recaptures the fact that traffic acceleration is bounded. The paper show how to calculate analytical solutions of the two-phase model for dynamic traffic situations, provides a set of calculation rules, and analyze...
Shell-model description of weakly bound and unbound nuclear states
International Nuclear Information System (INIS)
A consistent description of weakly bound and unbound nuclei requires an accurate description of the particle continuum properties when carrying out multiconfiguration mixing. This is the domain of the Gamow Shell Model (GSM) which is the multiconfigurational shell model in the complex k-plane formulated using a complete Berggren ensemble representing bound single-particle (s.p.) states, s.p. resonances, and non-resonant complex energy continuum states. We discuss the salient features of effective interactions in weakly bound systems and show selected applications of the GSM formalism to p-shell nuclei. Finally, a development of the new non-perturbative scheme based on Density Matrix Renormalization Group methods to select the most significant continuum configurations in GSM calculations is discussed shortly. (orig.)
A tightly bound soil-water scheme within an atmosphere-land-surface model
White, Rachel; Toumi, Ralf
2012-07-01
SummaryThe concept of tightly bound water, in which a reservoir of soil water is bound tightly within small soil pores but is still available for evapotranspiration, is parameterised for the first time within the land surface scheme of a fully-coupled regional-scale atmosphere-land surface model. The Weather Research and Forecasting (WRF) regional climate model and the NOAH land surface scheme are selected and a case study is performed on the Olifants River Basin in the Limpopo region of South Africa. Accurate knowledge of water availability in this water-stressed region is of great importance for adaptation and future water policy. Results of a simulation forced by ERA40 re-analysis show that the standard land surface scheme is unable to reproduce the observed runoff despite rainfall and atmospheric conditions similar to observed. This version of the model over-estimates mean annual runoff by 120%. The tightly bound water scheme shows a significant improvement, reducing the bias to 22%. The inclusion of the tightly bound water scheme has little effect on the basin average annual rainfall despite increasing annual evapotranspiration. The tightly bound water physics dampens the response of runoff to precipitation and provides additional de-coupling between precipitation and runoff, increasing the variability in this relationship. Simulations with the WRF model forced with both 1980s and 2040s CCSM3 data show that the tightly bound water scheme significantly reduces runoff in different climates and projects a greater relative future decrease in runoff, from 4% to 10% for the same precipitation decrease of 2.5%. The scheme also affects the projected changes in spatially averaged 100-year return precipitation and runoff with significance at the 0.9 confidence level.
Tang, Tie-Qiao; Luo, Xiao-Feng; Liu, Kai
2016-09-01
The driver's bounded rationality has significant influences on the micro driving behavior and researchers proposed some traffic flow models with the driver's bounded rationality. However, little effort has been made to explore the effects of the driver's bounded rationality on the trip cost. In this paper, we use our recently proposed car-following model to study the effects of the driver's bounded rationality on his running cost and the system's total cost under three traffic running costs. The numerical results show that considering the driver's bounded rationality will enhance his each running cost and the system's total cost under the three traffic running costs.
THE EXPERIMENTAL CHECK OF RELIABILITY OF MATHEMATICAL MODELS OF FRICTION JOINTS
Directory of Open Access Journals (Sweden)
A. Yu. Klyukin
2011-07-01
Full Text Available Problem statement. Up to now, there has been no model describing work of friction joints on high-strength bolts in elastic stage. All previous models describe the structure after macrodis-placement when bolt was subjected to shearing and crushing. There also has been no model of complex joint with gusset and linings.Results and conclusions. The bolted joint model involving substitution of the friction rigidity for elastic links is presented. Stresses in complex joints of metal bridge are determined experimentally. The results obtained with the use of the model are compared with experimental results. Stresses at the points of joint beyond the reach of experiment are calculated. Experimental results supported the validity of the model.
Frequency Weighted Model Order Reduction Technique and Error Bounds for Discrete Time Systems
Directory of Open Access Journals (Sweden)
Muhammad Imran
2014-01-01
for whole frequency range. However, certain applications (like controller reduction require frequency weighted approximation, which introduce the concept of using frequency weights in model reduction techniques. Limitations of some existing frequency weighted model reduction techniques include lack of stability of reduced order models (for two sided weighting case and frequency response error bounds. A new frequency weighted technique for balanced model reduction for discrete time systems is proposed. The proposed technique guarantees stable reduced order models even for the case when two sided weightings are present. Efficient technique for frequency weighted Gramians is also proposed. Results are compared with other existing frequency weighted model reduction techniques for discrete time systems. Moreover, the proposed technique yields frequency response error bounds.
Logic Model Checking of Time-Periodic Real-Time Systems
Florian, Mihai; Gamble, Ed; Holzmann, Gerard
2012-01-01
In this paper we report on the work we performed to extend the logic model checker SPIN with built-in support for the verification of periodic, real-time embedded software systems, as commonly used in aircraft, automobiles, and spacecraft. We first extended the SPIN verification algorithms to model priority based scheduling policies. Next, we added a library to support the modeling of periodic tasks. This library was used in a recent application of the SPIN model checker to verify the engine control software of an automobile, to study the feasibility of software triggers for unintended acceleration events.
Bounded confidence model on a still growing scale-free network
Sousa, A. O.
2004-01-01
A Bounded Confidence (BC) model of socio-physics, in which the agents have continuous opinions and can influence each other only if the distance between their opinions is below a threshold, is simulated on a still growing scale-free network considering several different strategies: for each new node (or vertex), that is added to the network all individuals of the network have their opinions updated following a BC model recipe. The results obtained are compared with the original model, with nu...
Sato, Kimiko; ODA, MEGUMI
2011-01-01
A questionnaire survey was administered to 317 parents who attended infant health check-ups in City B, Okayama Prefecture between October, 2008 and March, 2009. The questionnaire survey studied 7 factors based on the PRECEDE-PROCEED Model. We analysed factors that affected oral health behaviour and attendance at scheduled dental health check-ups. The survey containing 22 items concerning matters such as 'QOL' and 'health problems' was posted to parents and guardians in advance, and then colle...
DEFF Research Database (Denmark)
Guedes, J.M.; Rodrigues, H.C.; Bendsøe, Martin P.
2003-01-01
This paper describes a computational model, based on inverse homogenization and topology design, for approximating energy bounds for two-phase composites under multiple load cases. The approach allows for the identification of possible single-scale cellular materials that give rise to the optimal...
Orthogonality-condition model for bound states with a separable expansion of the potential
International Nuclear Information System (INIS)
A very efficient solution of the equation of Saito's orthogonality-condition model (OCM) is reported for bound states by means of a separable expansion of the potential (PSE method). Some simplifications of the published formulae of the PSE method is derived, which facilitate its application to the OCM and may be useful in solving the Schroedinger equation as well. (author)
Checking Fine and Gray subdistribution hazards model with cumulative sums of residuals
DEFF Research Database (Denmark)
Li, Jianing; Scheike, Thomas; Zhang, Mei Jie
2015-01-01
of residuals, which validate the model in three aspects: (1) proportionality of hazard ratio, (2) the linear functional form and (3) the link function. For each assumption testing, we provide a p-values and a visualized plot against the null hypothesis using a simulation-based approach. We also consider......Recently, Fine and Gray (J Am Stat Assoc 94:496–509, 1999) proposed a semi-parametric proportional regression model for the subdistribution hazard function which has been used extensively for analyzing competing risks data. However, failure of model adequacy could lead to severe bias in parameter...
A Framework for Relating Timed Transition Systems and Preserving TCTL Model Checking
DEFF Research Database (Denmark)
Jacobsen, Lasse; Jacobsen, Morten; Møller, Mikael Harkjær; Srba, Jiri
2010-01-01
Many formal translations between time dependent models have been proposed over the years. While some of them produce timed bisimilar models, others preserve only reachability or (weak) trace equivalence. We suggest a general framework for arguing when a translation preserves Timed Computation Tree...... Logic (TCTL) or its safety fragment.The framework works at the level of timed transition systems, making it independent of the modeling formalisms and applicable to many of the translations published in the literature. Finally, we present a novel translation from extended Timed-Arc Petri Nets to...
Propagators for scalar bound states at finite temperature in a NJL model
Zhou Bang Rong
2002-01-01
We show that, in a chiral $U_L(1)\\times U_R(1)$ NJL model, the physical propagators at finite temperature for scalar and pseudoscalar bound states in the imaginary-time formalism defined by amputated four-point functions, may have identical expressions to corresponding ones in the real-time formalism defined by diagonalization of amputated four-point function matrices only if the momentum $p$ of those bound states satisfy the condition $0\\leq p^2 < 4m^2$ ($m$ is the dynamical fermion mass). In the other case, the propagators in the two formalisms will have different imaginary parts in their denominators.
A Model-Free No-arbitrage Price Bound for Variance Options
Energy Technology Data Exchange (ETDEWEB)
Bonnans, J. Frederic, E-mail: frederic.bonnans@inria.fr [Ecole Polytechnique, INRIA-Saclay (France); Tan Xiaolu, E-mail: xiaolu.tan@polytechnique.edu [Ecole Polytechnique, CMAP (France)
2013-08-01
We suggest a numerical approximation for an optimization problem, motivated by its applications in finance to find the model-free no-arbitrage bound of variance options given the marginal distributions of the underlying asset. A first approximation restricts the computation to a bounded domain. Then we propose a gradient projection algorithm together with the finite difference scheme to solve the optimization problem. We prove the general convergence, and derive some convergence rate estimates. Finally, we give some numerical examples to test the efficiency of the algorithm.
Improved Frechet bounds and model-free pricing of multi-asset options
Tankov, Peter
2010-01-01
We compute the improved bounds on the copula of a bivariate random vector when partial information is available, such as the values of the copula on the subset of $[0,1]^2$, or the value of a functional of the copula, monotone with respect to the concordance order. These results are then used to compute model-free bounds on the prices of two-asset options which make use of extra information about the dependence structure, such as the price of another two-asset option.
DEFF Research Database (Denmark)
Herbert, Luke Thomas; Hansen, Zaza Nadja Lee
2016-01-01
This article presents a framework for the automated restructuring of stochastic workflows to reduce the impact of faults. The framework allows for the modelling of workflows by means of a formalised subset of the BPMN workflow language. We extend this modelling formalism to describe faults and...... model resources, associated with a workflow. The approach is fully automated and only the modelling of the production workflows, potential faults and the expression of the goals require manual input. We present the design of a software tool implementing this framework and explore the practical utility...... of this approach through an industrial case study in which the risk of production failures and their impact are reduced by restructuring the workflow....
Automated evolutionary restructuring of workflows to minimise errors via stochastic model checking
DEFF Research Database (Denmark)
Herbert, Luke Thomas; Hansen, Zaza Nadja Lee; Jacobsen, Peter
2014-01-01
This paper presents a framework for the automated restructuring of workflows that allows one to minimise the impact of errors on a production workflow. The framework allows for the modelling of workflows by means of a formalised subset of the Business Process Modelling and Notation (BPMN) language......, a well-established visual language for modelling workflows in a business context. The framework’s modelling language is extended to include the tracking of real-valued quantities associated with the process (such as time, cost, temperature). In addition, this language also allows for an intention...... by means of a case study from the food industry. Through this case study we explore the extent to which the risk of production faults can be reduced and the impact of these can be minimised, primarily through restructuring of the production workflows. This approach is fully automated and only the...
Kick, Alexander
2007-01-01
We present a reduction algorithm which reduces Kripke structures by eliminating transitions from the model which do not affect the visible components of the model. These are exactly the variables contained in the specification formula. The reduction algorithm preserves the truth of special CTL formulae. In contrast to formula-dependent reduction algorithms presented so far, which are mostly computationally expensive, our algorithm needs only one pass through the reachable ...
On the cosmic ray bound for models of extragalactic neutrino production
Mannheim, K; Rachen, J P
2001-01-01
We obtain the maximum diffuse neutrino intensity predicted by hadronic photoproduction models of active galactic nuclei, and other sources such as gamma ray bursts, that is consistent with the observed cosmic ray spectrum and diffuse extragalactic gamma ray background. For this, we compare the contributions to the cosmic ray intensity of extragalactic neutrino sources with the experimental data at energies above 10^15 eV, employing a transport calculation of energetic protons traversing cosmic photon backgrounds. We take into account source evolution, optical depth effects in the sources, and adiabatic losses of protons in magnetic fields on scales of galaxy clusters. The strongest cosmic ray bound applies to photoproduction sources which are optically thin for the emission of neutrons, and for which adiabatic losses of the protons resulting from neutron decay can be neglected. We find that our upper bound is strongly energy dependent, and is much higher than the bound obtained by Waxman and Bahcall at most e...
Efficient Localization Bounds in a Continuous N-Particle Anderson Model with Long-Range Interaction
Chulaevsky, Victor
2016-04-01
We establish strong dynamical and exponential spectral localization for a class of multi-particle Anderson models in a Euclidean space with an alloy-type random potential and a sub-exponentially decaying interaction of infinite range. For the first time in the mathematical literature, the uniform decay bounds on the eigenfunction correlators (EFCs) at low energies are proved, in the multi-particle continuous configuration space, in the (symmetrized) norm-distance, which is a natural distance in the multi-particle configuration space, and not in the Hausdorff distance. This results in uniform bounds on the EFCs in arbitrarily large but bounded domains in the physical configuration space, and not only in the actually infinite space, as in prior works on multi-particle localization in Euclidean spaces.
Propagators for Scalar Bound States at Finite Temperature in an NJL Model
Institute of Scientific and Technical Information of China (English)
ZHOU BangRong
2002-01-01
We re-examine physical causal propagators for scalar and pseudoscalar bound states at finite temperaturein a chiral Ut(1) x UR(1) NJL model, defined by four-point amputated fimctions subtracted through the gap equation,and prove that they are completely equivalent in the imaginary-time and real-time formalisms by separating carefiullythe imaginary part of the zero-temperature loop integral. It is shown that the same thermal transformation matrix ofthe matrix propagators for these bound states in the real-time formalism is precisely the one of the matrix propagatorfor an elementary scalar particle and this fact shows the similarity of thermodynamic property between a composite andelementary scalar particle. The retarded and advanced propagators for these bound states are also given explicitly fromthe imaginary-time formalism.
Kumar, Rajendra; Grubmüller, Helmut
2016-01-19
During replication of the ϕ29 bacteriophage inside a bacterial host cell, a DNA packaging motor transports the viral DNA into the procapsid against a pressure difference of up to 40 ± 20 atm. Several models have been proposed for the underlying molecular mechanism. Here we have used molecular dynamics simulations to examine the role of the connector part of the motor, and specifically the one-way revolution and the push-roll model. We have focused at the structure and intermolecular interactions between the DNA and the connector, for which a near-complete structure is available. The connector is found to induce considerable DNA deformations with respect to its canonical B-form. We further assessed by force-probe simulations to which extent the connector is able to prevent DNA leakage and found that the connector can act as a partial one-way valve by a check-valve mechanism via its mobile loops. Analysis of the geometry, flexibility, and energetics of channel lysine residues suggested that this arrangement of residues is incompatible with the observed DNA packaging step-size of ∼2.5 bp, such that the step-size is probably determined by the other components of the motor. Previously proposed DNA revolution and rolling motions inside the connector channel are both found implausible due to structural entanglement between the DNA and connector loops that have not been resolved in the crystal structure. Rather, in the simulations, the connector facilitates minor DNA rotation during the packaging process compatible with recent optical-tweezers experiments. Combined with the available experimental data, our simulation results suggest that the connector acts as a check-valve that prevents DNA leakage and induces DNA compression and rotation during DNA packaging. PMID:26789768
Brat, Guillaume P.; Martinie, Celia; Palanque, Philippe
2013-01-01
During early phases of the development of an interactive system, future system properties are identified (through interaction with end users in the brainstorming and prototyping phase of the application, or by other stakehold-ers) imposing requirements on the final system. They can be specific to the application under development or generic to all applications such as usability principles. Instances of specific properties include visibility of the aircraft altitude, speed… in the cockpit and the continuous possibility of disengaging the autopilot in whatever state the aircraft is. Instances of generic properties include availability of undo (for undoable functions) and availability of a progression bar for functions lasting more than four seconds. While behavioral models of interactive systems using formal description techniques provide complete and unambiguous descriptions of states and state changes, it does not provide explicit representation of the absence or presence of properties. Assessing that the system that has been built is the right system remains a challenge usually met through extensive use and acceptance tests. By the explicit representation of properties and the availability of tools to support checking these properties, it becomes possible to provide developers with means for systematic exploration of the behavioral models and assessment of the presence or absence of these properties. This paper proposes the synergistic use two tools for checking both generic and specific properties of interactive applications: Petshop and Java PathFinder. Petshop is dedicated to the description of interactive system behavior. Java PathFinder is dedicated to the runtime verification of Java applications and as an extension dedicated to User Interfaces. This approach is exemplified on a safety critical application in the area of interactive cockpits for large civil aircrafts.
Stringent dilepton bounds on left-right models using LHC data
Patra, Sudhanwa; Queiroz, Farinaldo S.; Rodejohann, Werner
2016-01-01
In canonical left-right symmetric models the lower mass bounds on the charged gauge bosons are in the ballpark of 3-4 TeV, resulting in much stronger limits on the neutral gauge boson ZR, making its production unreachable at the LHC. However, if one evokes different patterns of left-right symmetry breaking the ZR might be lighter than the WR± motivating an independent ZR collider study. In this work, we use the 8 TeV ATLAS 20.3 fb-1 luminosity data to derive robust bounds on the ZR mass using dilepton data. We find strong lower bounds on the ZR mass for different right-handed gauge couplings, excluding ZR masses up to ˜ 3.2 TeV. For the canonical LR model we place a lower mass bound of ˜ 2.5 TeV. Our findings are almost independent of the right-handed neutrino masses (˜ 2% effect) and applicable to general left-right models.
Model checking a cache coherence protocol for a Java DSM implementation
Pang, J.; Fokkink, W.J.; Hofman, R.; Veldema, R.
2007-01-01
Jackal is a fine-grained distributed shared memory implementation of the Java programming language. It aims to implement Java's memory model and allows multithreaded Java programs to run unmodified on a distributed memory system. It employs a multiple-writer cache coherence protocol. In this paper,
Lee, Young-Sun; Wollack, James A.; Douglas, Jeffrey
2009-01-01
The purpose of this study was to assess the model fit of a 2PL through comparison with the nonparametric item characteristic curve (ICC) estimation procedures. Results indicate that three nonparametric procedures implemented produced ICCs that are similar to that of the 2PL for items simulated to fit the 2PL. However for misfitting items,…
Model based feasibility study on bidirectional check valves in wave energy converters
DEFF Research Database (Denmark)
Hansen, Anders Hedegaard; Pedersen, Henrik C.; Andersen, Torben Ole
2014-01-01
valves in wave energy converters to improve the system efficiency. A single float arm of the Wavestar wave energy converter is modelled including the power take-off (PTO) system. The primary stage of the utilised PTO-system is a discrete fluid power force system consisting of a multi-chamber cylinder and...
Fluid-structure interaction model to check up discharging pipe system
International Nuclear Information System (INIS)
Within phenomena group that occur in a pipelines system that lead some fluid in stationary state, the loss of lateral stability is which one of the more common and important of them since it is showed in periodic vibrations or aleatories, way against whose effects it will have to be designed the piping to avoid catastrophic failures. The present work is a part of the realized effort for incorporating to the programs of digital computers used for the structural analysis of piping systems based in the finite element method. It is a model that includes the lateral effect that induces the fluid on the pipes. For this effect was planted and obtained a model or element for straight pipes segments. It was through the use of analytical variational methods and polynomial approximations (typical techniques using in finite elements). When were effected the calculations of characteristic frequencies in straight pipe sections configurations. It was obtained concordance with the analytical predictions. There fore it was demonstrated that the model is correct. A continuation of this work will be to obtain the models for curved segments of piping. (Author)
Invariant Measures and Asymptotic Gaussian Bounds for Normal Forms of Stochastic Climate Model
Institute of Scientific and Technical Information of China (English)
Yuan YUAN; Andrew J.MAJDA
2011-01-01
The systematic development of reduced low-dimensional stochastic climate models from observations or comprehensive high dimensional climate models is an important topic for atmospheric low-frequency variability, climate sensitivity, and improved extended range forecasting. Recently, techniques from applied mathematics have been utilized to systematically derive normal forms for reduced stochastic climate models for low-frequency variables. It was shown that dyad and multiplicative triad interactions combine with the climatological linear operator interactions to produce a normal form with both strong nonlinear cubic dissipation and Correlated Additive and Multiplicative (CAM) stochastic noise. The probability distribution functions (PDFs) of low frequency climate variables exhibit small but significant departure from Gaussianity but have asymptotic tails which decay at most like a Gaussian. Here, rigorous upper bounds with Gaussian decay are proved for the invariant measure of general normal form stochastic models. Asymptotic Gaussian lower bounds are also established under suitable hypotheses.
A Machine Checked Model of Idempotent MGU Axioms For Lists of Equational Constraints
Kothari, Sunil; 10.4204/EPTCS.42.3
2010-01-01
We present formalized proofs verifying that the first-order unification algorithm defined over lists of satisfiable constraints generates a most general unifier (MGU), which also happens to be idempotent. All of our proofs have been formalized in the Coq theorem prover. Our proofs show that finite maps produced by the unification algorithm provide a model of the axioms characterizing idempotent MGUs of lists of constraints. The axioms that serve as the basis for our verification are derived from a standard set by extending them to lists of constraints. For us, constraints are equalities between terms in the language of simple types. Substitutions are formally modeled as finite maps using the Coq library Coq.FSets.FMapInterface. Coq's method of functional induction is the main proof technique used in proving many of the axioms.
A Machine Checked Model of Idempotent MGU Axioms For Lists of Equational Constraints
Directory of Open Access Journals (Sweden)
Sunil Kothari
2010-12-01
Full Text Available We present formalized proofs verifying that the first-order unification algorithm defined over lists of satisfiable constraints generates a most general unifier (MGU, which also happens to be idempotent. All of our proofs have been formalized in the Coq theorem prover. Our proofs show that finite maps produced by the unification algorithm provide a model of the axioms characterizing idempotent MGUs of lists of constraints. The axioms that serve as the basis for our verification are derived from a standard set by extending them to lists of constraints. For us, constraints are equalities between terms in the language of simple types. Substitutions are formally modeled as finite maps using the Coq library Coq.FSets.FMapInterface. Coq's method of functional induction is the main proof technique used in proving many of the axioms.
Directory of Open Access Journals (Sweden)
Jörg Becker
2012-11-01
Full Text Available With a steady increase of regulatory requirements for business processes, automation support of compliance management is a field garnering increasing attention in Information Systems research. Several approaches have been developed to support compliance checking of process models. One major challenge for such approaches is their ability to handle different modeling techniques and compliance rules in order to enable widespread adoption and application. Applying a structured literature search strategy, we reflect and discuss compliance-checking approaches in order to provide an insight into their generalizability and evaluation. The results imply that current approaches mainly focus on special modeling techniques and/or a restricted set of types of compliance rules. Most approaches abstain from real-world evaluation which raises the question of their practical applicability. Referring to the search results, we propose a roadmap for further research in model-based business process compliance checking.
Directory of Open Access Journals (Sweden)
Lin Chen
2014-01-01
Full Text Available To reduce time for collision detection among articulated models, the collision detection algorithm of Hybrid Bounding Volume Hierarchy Tree (HBVHT was proposed to accelerate the speed of culling away triangles. The HBVHT was composed of two phases: A broad phase and a narrow phase. The broad phase consisted of Axis-Aligned Bounding Box (AABB and the Bounding Volume (BV was used to build a Multi-Level Hierarchy Tree (MLHT; the narrow phase was made up of the Oriented Bounding Box (OBB hierarchy trees and triangles. Furthermore, according to the characteristic of hierarchical structure of the HBVHT, an improved cost function was given to analyze the performance of the HBVHT. Experiments were performed between two 6-DOF robots under the Open GL environment. Two robots with the same number of triangles moved with the same trajectory for the collision experiments. Experimental results show that the efficiency of HBVHT algorithm is higher than that of the RAPID and the other two HBVHTs with different structure. The results indicate that the HBVHT algorithm can effectively improve the efficiency of collision detection among the articulated model robots.
Modelling light-cone distribution amplitudes from non-relativistic bound states
International Nuclear Information System (INIS)
We calculate light-cone distribution amplitudes for non-relativistic bound states, including radiative corrections from relativistic gluon exchange to first order in the strong coupling constant. We distinguish between bound states of quarks with equal (or similar) mass, m1 ∼ m2, and between bound states where the quark masses are hierarchical, m1 >> m2. For both cases we calculate the distribution amplitudes at the non-relativistic scale and discuss the renormalization-group evolution for the leading-twist and 2-particle distributions. Our results apply to hard exclusive reactions with non-relativistic bound states in the QCD factorization approach like, for instance, Bc → ηclν or e+e- → J/ψηc. They also serve as a toy model for light-cone distribution amplitudes of light mesons or heavy B and D mesons, for which certain model-independent properties can be derived. In particular, we calculate the anomalous dimension for the B meson distribution amplitude φB-(ω) in the Wandzura-Wilczek approximation and derive the according solution of the evolution equation at leading logarithmic accuracy
Kang, Soo Hoon; Lim, Yaeji; Lee, Hyuk; Kim, Joungyoun; Chi, Sangah; Min, Yang Won; Min, Byung-Hoon; Lee, Jun Haeng; Son, Hee Jung; Ryu, Seungho; Rhee, Poong-Lyul; Kim, Jae J
2016-01-01
Erosive esophagitis is a major risk factor for Barrett esophagus and esophageal adenocarcinoma. Information regarding the putative risk factors for developing erosive esophagitis is considerably heterogeneous; thus, a risk model is required to clinically predict the incidence of erosive esophagitis. This study was to derive and validate a predictive model for the incidence of developing erosive esophagitis after negative index endoscopy in a population subjected to routine health check-ups. This retrospective cohort study of health check-ups included 11,535 patients who underwent repeated screening endoscopy after >3 years from a negative index endoscopy. We used logistic regression analysis to predict the incidence of erosive esophagitis, and a Simple Prediction of Erosive Esophagitis Development score for risk assessment was developed and internally validated using the split-sample approach. The development and validation cohorts included 5765 patients (675 with erosive esophagitis [11.7%]) and 5770 patients (670 with erosive esophagitis [11.6%]), respectively. The final model included sex, smoking behavior, body mass index, hypertension, and the triglyceride level as variables. This model predicted 667 cases of erosive esophagitis, yielding an expected-to-observed ratio of 1.00 (95% confidence interval [CI], 0.92-1.07). A simplified 5-item risk scoring system based on coefficients was developed, with a risk of erosive esophagitis of 6.2% (95% CI, 5.2-7.1) for the low-risk group (score ≤2), 15.1% (95% CI, 13.5-16.6) for the intermediate-risk group (score ≤3, 4), and 18.2% (95% CI, 15.2-21.3) for the high-risk group (score ≥5). The discriminative performance of the risk-prediction score was consistent in the derivation cohort and validation cohort (c-statistics 0.68 and 0.64, respectively); the calibration was good (Brier score 0.099 and 0.1, respectively). In conclusion, a simple risk-scoring model using putative risk factors can predict the future
Faria, J. M.; Mahomad, S.; Silva, N.
2009-05-01
The deployment of complex safety-critical applications requires rigorous techniques and powerful tools both for the development and V&V stages. Model-based technologies are increasingly being used to develop safety-critical software, and arguably, turning to them can bring significant benefits to such processes, however, along with new challenges. This paper presents the results of a research project where we tried to extend current V&V methodologies to be applied on UML/SysML models and aiming at answering the demands related to validation issues. Two quite different but complementary approaches were investigated: (i) model checking and the (ii) extraction of robustness test-cases from the same models. These two approaches don't overlap and when combined provide a wider reaching model/design validation ability than each one alone thus offering improved safety assurance. Results are very encouraging, even though they either fell short of the desired outcome as shown for model checking, or still appear as not fully matured as shown for robustness test case extraction. In the case of model checking, it was verified that the automatic model validation process can become fully operational and even expanded in scope once tool vendors help (inevitably) to improve the XMI standard interoperability situation. For the robustness test case extraction methodology, the early approach produced interesting results but need further systematisation and consolidation effort in order to produce results in a more predictable fashion and reduce reliance on expert's heuristics. Finally, further improvements and innovation research projects were immediately apparent for both investigated approaches, which point to either circumventing current limitations in XMI interoperability on one hand and bringing test case specification onto the same graphical level as the models themselves and then attempting to automate the generation of executable test cases from its standard UML notation.
Tevatron Higgs Mass Bounds: Projecting U(1)' Models to LHC Domain
Sert, Hale; Demir, Durmus A; Solmaz, Levent
2010-01-01
We study Higgs boson masses in supersymmetric models with an extra U(1) symmetry to be called U(1)$^{\\prime}$. Such extra gauge symmetries are urged by the $\\mu$ problem of the MSSM, and they also arise frequently in low-energy supersymmetric models stemming from GUTs and strings. We analyze mass of the lightest Higgs boson and various other particle masses and couplings by taking into account the LEP bounds as well as the recent bounds from Tevatron experiments. We find that the $\\mu$-problem motivated generic low-energy U(1)$^{\\prime}$ model yields Higgs masses as large as $\\sim 200\\ {\\rm GeV}$ and violate the Tevatron bounds for certain ranges of parameters. We analyze correlations among various model parameters, and determine excluded regions by both scanning the parameter space and by examining certain likely parameter values. We also make educated projections for LHC measurements in light of the Tevatron restrictions on the parameter space. We further analyze certain benchmark models stemming from E(6) ...
Directory of Open Access Journals (Sweden)
Bonura Carlo A
2001-04-01
Full Text Available Abstract Background A previous report showed that the open field behavior of rats sensitized to the dopamine agonist quinpirole satisfies 5 performance criteria for compulsive checking behavior. In an effort to extend the parallel between the drug-induced phenomenon and human obsessive-compulsive disorder (OCD, the present study investigated whether the checking behavior of quinpirole rats is subject to interruption, which is an attribute characteristic of OCD compulsions. For this purpose, the rat's home-cage was placed into the open field at the beginning or the middle of a 2-hr test. Results Introduction of the home-cage reduced checking behavior, as rats stayed inside the cage. After 40 min, checking resurfaced, as quinpirole rats exited the home-cage often. An unfamiliar cage had no such effects on quinpirole rats or saline controls. Conclusions Checking behavior induced by quinpirole is not irrepressible but can be suspended. Results strengthen the quinpirole preparation as an animal model of OCD compulsive checking.
Krause, Christian; 10.4204/EPTCS.73.8
2011-01-01
The assurance of quality of service properties is an important aspect of service-oriented software engineering. Notations for so-called service level agreements (SLAs), such as the Web Service Level Agreement (WSLA) language, provide a formal syntax to specify such assurances in terms of (legally binding) contracts between a service provider and a customer. On the other hand, formal methods for verification of probabilistic real-time behavior have reached a level of expressiveness and efficiency which allows to apply them in real-world scenarios. In this paper, we suggest to employ the recently introduced model of Interval Probabilistic Timed Automata (IPTA) for formal verification of QoS properties of service-oriented systems. Specifically, we show that IPTA in contrast to Probabilistic Timed Automata (PTA) are able to capture the guarantees specified in SLAs directly. A particular challenge in the analysis of IPTA is the fact that their naive semantics usually yields an infinite set of states and infinitely...
Model Checking of Credit Setting in AFDX Traffic Policing%AFDX流量管制信用量设置的模型检查
Institute of Scientific and Technical Information of China (English)
高宇; 李峭; 熊华钢
2011-01-01
航空电子全双工交换式以太网(AFDX)实时通信中,交换节点采用信用量令牌桶(creditedtoken bucket)进行流量管制.分别对基于帧和基于字节的信用量令牌桶流量管制进行时间自动机建模,并构建模型的并发交互场景;采用测试自动机,进行有界活性(bounded liveness)模型检查.通过形式化验证,发现流量管制通过约束突发度限制多路复用输出排队的时延抖动,但信用量值的设置必须考虑输入虚拟链路(VL)的时延抖动,否则可能导致已经聚合的流量中属于不同VL的帧的先后次序被破坏,反而造成更大的时延抖动.通过分析时延抖动对信用量设置的影响,归纳并给出流量管制信用量设置的注意事项.%In the Avionics Full Duplex Switchsd Ethernet (AFDX) real- time communications,credited token buckets are applied in switched nodes for traffic policing. Test antomata are designed for bounded liveness nodel checking under concurrent interaction scenarios with the thme automata models,which are.built for the frame- based and byte- based credited token buckets respectively. According to the formal verification ,it's shown that latency jitters in multiplexer output queuing are limited by traffic policing with burstiness constraints. However,jitters of input virtual links (VL) should also be considered when setting the credit values ;otherwise,the greater jitter values may be caused by disturbing aggregated frames belong to different VLs. By analyzing the inter- relations of credit setting and jitters,some notes are summarized for traffic policing configurations.
Automatic Verification of Biochemical Network Using Model Checking Method%基于模型校核的生化网络自动辨别方法
Institute of Scientific and Technical Information of China (English)
Jinkyung Kim; Younghee Lee; Il Moon
2008-01-01
This study focuses on automatic searching and verifying methods for the reachability, transition logics and hierarchical structure in all possible paths of biological processes using model checking. The automatic search and verification for alternative paths within complex and large networks in biological process can provide a consid-erable amount of solutions, which is difficult to handle manually. Model checking is an automatic method for veri-fying if a circuit or a condition, expressed as a concurrent transition system, satisfies a set of properties expressed ina temporal logic, such as computational tree logic (CTL). This article represents that model checking is feasible in biochemical network verification and it shows certain advantages over simulation for querying and searching of special behavioral properties in biochemical processes.
DEFF Research Database (Denmark)
Grønhøj Larsen, Christian; Jørgensen, Karsten Juhl; Gøtzsche, Peter C
2012-01-01
To investigate whether Danish providers of general health checks present a balanced account of possible benefits and harms on their websites and whether the health checks are evidence-based.......To investigate whether Danish providers of general health checks present a balanced account of possible benefits and harms on their websites and whether the health checks are evidence-based....
Upper bound on the gluino mass in supersymmetric models with extra matters
Moroi, Takeo; Yanagida, Tsutomu T.; Yokozaki, Norimi
2016-09-01
We discuss the upper bound on the gluino mass in supersymmetric models with vector-like extra matters. In order to realize the observed Higgs mass of 125 GeV, the gluino mass is bounded from above in supersymmetric models. With the existence of the vector-like extra matters at around TeV, we show that such an upper bound on the gluino mass is significantly reduced compared to the case of minimal supersymmetric standard model. This is due to the fact that radiatively generated stop masses as well the stop trilinear coupling are enhanced in the presence of the vector-like multiplets. In a wide range of parameter space of the model with extra matters, particularly with sizable tan β (which is the ratio of the vacuum expectation values of the two Higgs bosons), the gluino is required to be lighter than ∼ 3 TeV, which is likely to be within the reach of forthcoming LHC experiment.
International Nuclear Information System (INIS)
We calculate upper and lower bounds on the modulus of the pion electromagnetic form factor on the unitarity cut below the ωπ inelastic threshold, using as input the phase in the elastic region known via the Fermi-Watson theorem from the ππ P-wave phase shift, and a suitably weighted integral of the modulus squared above the inelastic threshold. The normalization at t=0, the pion charge radius and experimental values at spacelike momenta are used as additional input information. The bounds are model independent, in the sense that they do not rely on specific parametrizations and do not require assumptions on the phase of the form factor above the inelastic threshold. The results provide nontrivial consistency checks on the recent experimental data on the modulus available below the ωπ threshold from e + e - annihilation and τ-decay experiments. In particular, at low energies the calculated bounds offer a more precise description of the modulus than the experimental data. (orig.)
Model-Independent Analysis of B -> pi K Decays and Bounds on the Weak Phase gamma
Neubert, Matthias(PRISMA Cluster of Excellence & Mainz Institut for Theoretical Physics, Johannes Gutenberg University, D-55099, Mainz, Germany)
1998-01-01
A general parametrization of the amplitudes for the rare two-body decays B -> pi K is introduced, which makes maximal use of theoretical constraints arising from flavour symmetries of the strong interactions and the structure of the low-energy effective weak Hamiltonian. With the help of this parametrization, a model-independent analysis of the branching ratios and direct CP asymmetries in the various B -> pi K decay modes is performed, and the impact of hadronic uncertainties on bounds on th...
A relativistic gauge model describing N particles bound by harmonic forces
International Nuclear Information System (INIS)
Application of the principle of gauging to linear canonical symmetries of simplest (rudimentary) bilinear lagrangians is shown to produce a relativistic version of the lagrangian describing N particles bound by harmonic forces. For pairwise coupled identical particles the gauge group is T1xU1xSUN-1. A model for the relativistic discrete string (a chain of N particles) is also discussed. All these gauge theories of particles can be quantized by standard methods. (orig.)
Two Gamma Decay Width of D Meson in Bound State Model
International Nuclear Information System (INIS)
We have estimated the two gamma decay width of D meson by using the bound state model of Holdom and Sutherland. Here we have derived an effective quark level Lagrangian for c → uγ and c → uγγ and hence we have calculated the decay width of D → γγ. We have obtained the branching ratio for the above decay mode as: Br (Do → 2γ) 8.63 x 10-6. (author)
Energy Technology Data Exchange (ETDEWEB)
Melintescu, A.; Galeriu, D. [' Horia Hulubei' National Institute for Physics and Nuclear Engineering, Bucharest-Magurele (Romania); Diabate, S.; Strack, S. [Institute of Toxicology and Genetics, Karlsruhe Institute of Technology - KIT, Eggenstein-Leopoldshafen (Germany)
2015-03-15
The processes involved in tritium transfer in crops are complex and regulated by many feedback mechanisms. A full mechanistic model is difficult to develop due to the complexity of the processes involved in tritium transfer and environmental conditions. First, a review of existing models (ORYZA2000, CROPTRIT and WOFOST) presenting their features and limits, is made. Secondly, the preparatory steps for a robust model are discussed, considering the role of dry matter and photosynthesis contribution to the OBT (Organically Bound Tritium) dynamics in crops.
Vacuum stability bounds in Anomaly and Gaugino Mediated SUSY breaking models
Gabrielli, E; Roy, S; Gabrielli, Emidio; Huitu, Katri; Roy, Sourov
2002-01-01
We constrain the parameter space of the minimal and gaugino-assisted anomaly mediation, and gaugino mediation models by requiring that the electroweak vacuum corresponds to the deepest minimum of the scalar potential. In the framework of anomaly mediation models we find strong lower bounds on slepton and squark masses. In the gaugino mediation models the mass spectrum is forced to be at the TeV scale. We find extensive regions of the parameter space which are ruled out, even at low tan(beta). The implications of these results on the g-2 of the muon are also analyzed.
International Nuclear Information System (INIS)
The processes involved in tritium transfer in crops are complex and regulated by many feedback mechanisms. A full mechanistic model is difficult to develop due to the complexity of the processes involved in tritium transfer and environmental conditions. First, a review of existing models (ORYZA2000, CROPTRIT and WOFOST) presenting their features and limits, is made. Secondly, the preparatory steps for a robust model are discussed, considering the role of dry matter and photosynthesis contribution to the OBT (Organically Bound Tritium) dynamics in crops
Bounds for avalanche critical values of the Bak-Sneppen model
Gillett, Alexis; Meester, Ronald; Nuyens, Misja
2005-01-01
We study the Bak-Sneppen model on locally finite transitive graphs $G$, in particular on Z^d and on T_Delta, the regular tree with common degree Delta. We show that the avalanches of the Bak-Sneppen model dominate independent site percolation, in a sense to be made precise. Since avalanches of the Bak-Sneppen model are dominated by a simple branching process, this yields upper and lower bounds for the so-called avalanche critical value $p_c^{BS}(G)$. Our main results imply that 1/(Delta+1)
Directory of Open Access Journals (Sweden)
Saeid Mokhtarian
2014-01-01
Full Text Available Despite extensive area of applications, simulation of complex wall bounded problems or any deformable boundary is still a challenge in a Dissipative Particle Dynamics simulation. This limitation is rooted in the soft force nature of DPD and the fact that we need to use an antipenetration model for escaped particles. In the present paper, we propose a new model of antipenetration which preserves the conservation of linear momentum on the boundaries and enables us to simulate complex and flexible boundaries. Finally by performing numerical simulations, we demonstrate the validity of our new model.
Directory of Open Access Journals (Sweden)
NEETHU GEORGE , J.SELVAKUMAR
2013-04-01
Full Text Available Natural language (NL is any language that arises in an unpremeditated fashion as the result of the innate facility for language possessed by the human intellect. A natural language is typically used for communication, and may be spoken, signed/written. Natural language (NL is still widely used for developing software requirements specifications or other artifacts created for documenting requirements. However, natural language deliverables suffer from ambiguity, inconsistency and incompleteness. This work presents a methodology that produces model based test cases considering natural language requirements. Natural language requirements are converted in to state chart models and test cases are generated from state chart models. Inconsistency is a major problem that permeates all aspects of software development. Inconsistency occurs when a specification contains conflicting, contradictory description of the expected behavior of the system to be built or of its domain.Incompleteness contributes to one of the very serious problems that are present in software specifications. Existence of defects such as incompleteness certainly generates a source code that doesn’t meet the undisclosed goals of the customers resulting in the generation of incoherent system and acceptance test cases. This paper proposes a methodology for dealing with defects such as incompleteness and inconsistency in natural language requirements deliverables. Model checking combined with k-permutations of n values of variables and specification patterns were used to detect incompleteness in software specifications. A method using both theorem-proving and model-checking techniques were used for automatically discovering inconsistencies in the requirements.
A Bounding Surface Plasticity Model for Intact Rock Exhibiting Size-Dependent Behaviour
Masoumi, Hossein; Douglas, Kurt J.; Russell, Adrian R.
2016-01-01
A new constitutive model for intact rock is presented recognising that rock strength, stiffness and stress-strain behaviour are affected by the size of the rock being subjected to loading. The model is formulated using bounding surface plasticity theory. It is validated against a new and extensive set of unconfined compression and triaxial compression test results for Gosford sandstone. The samples tested had diameters ranging from 19 to 145 mm and length-to-diameter ratios of 2. The model captures the continuous nonlinear stress-strain behaviour from initial loading, through peak strength to large shear strains, including transition from brittle to ductile behaviour. The size dependency was accounted for through a unified size effect law applied to the unconfined compressive strength—a key model input parameter. The unconfined compressive strength increases with sample size before peaking and then decreasing with further increasing sample size. Inside the constitutive model two hardening laws act simultaneously, each driven by plastic shear strains. The elasticity is stress level dependent. Simple linear loading and bounding surfaces are adopted, defined using the Mohr-Coulomb criterion, along with a non-associated flow rule. The model simulates well the stress-strain behaviour of Gosford sandstone at confining pressures ranging from 0 to 30 MPa for the variety of sample sizes considered.
Directory of Open Access Journals (Sweden)
Sato,Kimiko
2011-04-01
Full Text Available A questionnaire survey was administered to 317 parents who attended infant health check-ups in City B, Okayama Prefecture between October, 2008 and March, 2009. The questionnaire survey studied 7 factors based on the PRECEDE-PROCEED Model. We analysed factors that affected oral health behaviour and attendance at scheduled dental health check-ups. The survey containing 22 items concerning matters such as 'QOL' and 'health problems' was posted to parents and guardians in advance, and then collected on the day of the medical check-up. The collected data was analysed using the t-test and Pearson's correlation coefficient, following which we conducted a covariance structure analysis. The results showed that dental health behaviour was directly affected by reinforcing factors, and indirectly associated with enabling and predisposing factors influenced by reinforcing factors. It was also shown that predisposing factors and oral health behaviour were associated with attendance at scheduled oral health check-ups. The results indicated that strengthening oral health education by sharing knowledge that acts as predisposing factors and introducing adaptations of oral health behaviour that that fit individual lives will lead to improved attendance at scheduled dental health check-ups.
Sato, Kimiko; Oda, Megumi
2011-04-01
A questionnaire survey was administered to 317 parents who attended infant health check-ups in City B, Okayama Prefecture between October, 2008 and March, 2009. The questionnaire survey studied 7 factors based on the PRECEDE-PROCEED Model. We analysed factors that affected oral health behaviour and attendance at scheduled dental health check-ups. The survey containing 22 items concerning matters such as 'QOL' and 'health problems' was posted to parents and guardians in advance, and then collected on the day of the medical check-up. The collected data was analysed using the t-test and Pearson's correlation coefficient, following which we conducted a covariance structure analysis. The results showed that dental health behaviour was directly affected by reinforcing factors, and indirectly associated with enabling and predisposing factors influenced by reinforcing factors. It was also shown that predisposing factors and oral health behaviour were associated with attendance at scheduled oral health check-ups. The results indicated that strengthening oral health education by sharing knowledge that acts as predisposing factors and introducing adaptations of oral health behaviour that that fit individual lives will lead to improved attendance at scheduled dental health check-ups. PMID:21519364
Models of atoms in plasmas based on common formalism for bound and free electrons
International Nuclear Information System (INIS)
Atom-in-plasma models: Thomas-Fermi (TF) and INFERNO, AJCI and VAAQP, that use the same formalism for all electrons are briefly described and analyzed from the point of view of their thermodynamic consistence. While the TF and VAAQP models may be derived from variational principle and respect the virial theorem, it appears that two earlier quantum extensions of the quasi-classical TF model, INFERNO and AJCI, are not fully variational. The problems of the two latter approaches are analyzed from the point of view of the VAAQP model. However all quantum models seem to give unrealistic description of atoms in plasma at low temperature and high plasma densities. These difficulties are connected with the Wigner-Seitz cavity approach to non-central ions that is present in all considered models. Comparison of some equation-of-state data from TF, INFERNO and VAAQP models are shown on a chosen example. We report also on the status of our research on the frequency-dependent linear-response theory of atoms in plasma. A new Ehrenfest-type sum rule, originally proposed in the quantum VAAQP model, was proven in the case of the response of the TF atom with the Bloch hydrodynamics (TFB) and checked by numerical example. The TFB case allows one to have a direct insight into the rather involved mathematics of the self-consistent linear response calculations in situations when both the central atom and its plasma vicinity are perturbed by an electric field. (authors)
Models of atoms in plasmas based on common formalism for bound and free electrons
Blenski, T.; Piron, R.; Caizergues, C.; Cichocki, B.
2013-12-01
Atom-in-plasma models: Thomas-Fermi (TF) and INFERNO, AJCI and VAAQP, that use the same formalism for all electrons are briefly described and analyzed from the point of view of their thermodynamic consistence. While the TF and VAAQP models may be derived from variational principle and respect the virial theorem, it appears that two earlier quantum extensions of the quasi-classical TF model, INFERNO and AJCI, are not fully variational. The problems of the two latter approaches are analyzed from the point of view of the VAAQP model. However all quantum models seem to give unrealistic description of atoms in plasma at low temperature and high plasma densities. These difficulties are connected with the Wigner-Seitz cavity approach to non-central ions that is present in all considered models. Comparison of some equation-of-state data from TF, INFERNO and VAAQP models are shown on a chosen example. We report also on the status of our research on the frequency-dependent linear-response theory of atoms in plasma. A new Ehrenfest-type sum rule, originally proposed in the quantum VAAQP model, was proven in the case of the response of the TF atom with the Bloch hydrodynamics (TFB) and checked by numerical example. The TFB case allows one to have a direct insight into the rather involved mathematics of the self-consistent linear response calculations in situations when both the central atom and its plasma vicinity are perturbed by an electric field.
Atmospheric inverse modeling with known physical bounds: an example from trace gas emissions
Directory of Open Access Journals (Sweden)
S. M. Miller
2013-09-01
Full Text Available Many inverse problems in the atmospheric sciences involve parameters with known physical constraints. Examples include non-negativity (e.g., emissions of some urban air pollutants or upward limits implied by reaction or solubility constants. However, probabilistic inverse modeling approaches based on Gaussian assumptions cannot incorporate such bounds and thus often produce unrealistic results. The atmospheric literature lacks consensus on the best means to overcome this problem, and existing atmospheric studies rely on a limited number of the possible methods with little examination of the relative merits of each. This paper investigates the applicability of several approaches to bounded inverse problems and is also the first application of Markov chain Monte Carlo (MCMC to estimation of atmospheric trace gas fluxes. The approaches discussed here are broadly applicable. A common method of data transformations is found to unrealistically skew estimates for the examined example application. The method of Lagrange multipliers and two MCMC methods yield more realistic and accurate results. In general, the examined MCMC approaches produce the most realistic result but can require substantial computational time. Lagrange multipliers offer an appealing alternative for large, computationally intensive problems when exact uncertainty bounds are less central to the analysis. A synthetic data inversion of US anthropogenic methane emissions illustrates the strengths and weaknesses of each approach.
... Medical Conditions Nutrition & Fitness Emotional Health Annual Check-Up Posted under Health Guides . Updated 7 January 2015. + ... I get ready for my annual medical check-up? If this is your first visit to your ...
Darwin, Ian
2007-01-01
This Short Cut tells you about tools that will improve the quality of your Java code, using checking above and beyond what the standard tools do, including: Using javac options, JUnit and assertions Making your IDE work harder Checking your source code with PMD Checking your compiled code (.class files) with FindBugs Checking your program's run-time behavior with Java PathFinder
Preferential Attachment Model with Degree Bound and its Application to Key Predistribution in WSN
Ruj, Sushmita
2016-01-01
Preferential attachment models have been widely studied in complex networks, because they can explain the formation of many networks like social networks, citation networks, power grids, and biological networks, to name a few. Motivated by the application of key predistribution in wireless sensor networks (WSN), we initiate the study of preferential attachment with degree bound. Our paper has two important contributions to two different areas. The first is a contribution in the study of complex networks. We propose preferential attachment model with degree bound for the first time. In the normal preferential attachment model, the degree distribution follows a power law, with many nodes of low degree and a few nodes of high degree. In our scheme, the nodes can have a maximum degree $d_{\\max}$, where $d_{\\max}$ is an integer chosen according to the application. The second is in the security of wireless sensor networks. We propose a new key predistribution scheme based on the above model. The important features ...
The Cramer-Rao Bound and DMT Signal Optimisation for the Identification of a Wiener-Type Model
Directory of Open Access Journals (Sweden)
H. Koeppl
2004-09-01
Full Text Available In linear system identification, optimal excitation signals can be determined using the Cramer-Rao bound. This problem has not been thoroughly studied for the nonlinear case. In this work, the Cramer-Rao bound for a factorisable Volterra model is derived. The analytical result is supported with simulation examples. The bound is then used to find the optimal excitation signal out of the class of discrete multitone signals. As the model is nonlinear in the parameters, the bound depends on the model parameters themselves. On this basis, a three-step identification procedure is proposed. To illustrate the procedure, signal optimisation is explicitly performed for a third-order nonlinear model. Methods of nonlinear optimisation are applied for the parameter estimation of the model. As a baseline, the problem of optimal discrete multitone signals for linear FIR filter estimation is reviewed.
Bound and unbound nuclear systems at the drip lines: a one-dimensional model
Moschini, L.; Pérez-Bernal, F.; Vitturi, A.
2016-08-01
We construct a one-dimensional toy model to describe the main features of Borromean nuclei at the continuum threshold. The model consists of a core and two valence neutrons, unbound in the mean potential, that are bound by a residual point contact density-dependent interaction. Different discretization procedures are used (harmonic oscillator and transformed harmonic oscillator bases, or use of large rigid wall box). Resulting energies and wave functions, as well as inelastic transition intensities, are compared within the different discretization techniques, as well as with the exact results in the case of one particle and with the results of the di-neutron cluster model in the two particles case. Despite its simplicity, this model includes the main physical features of the structure of Borromean nuclei in an intuitive and computationally affordable framework, and will be extended to direct reaction calculations.
Pexeso ("Concentration game") as an arbiter of bounded-rationality models
Czech Academy of Sciences Publication Activity Database
Kuběna, Aleš Antonín
České Budějovice : University of South Bohemia, 2010 - (Houda, M.; Friebelová, J.), s. 337-380 ISBN 978-80-7394-218-2. [28-th International Conference on Mathematical Methods in Economics. České Budějovice (CZ), 08.09.2010-10.09.2010] R&D Projects: GA ČR GD402/09/H045 Institutional research plan: CEZ:AV0Z10750506 Keywords : Concentration game * pexeso * perfect players Subject RIV: AH - Economics http://library.utia.cas.cz/separaty/2010/E/kubena-pexeso (concentration game) as an arbiter of bounded-rationality models.pdf
What is a leader of opinion formation in bounded confidence models?
Kurmyshev, E
2013-01-01
Taking a decision in democratic social groups is based on the opinion of the majority or on the consensus. So, the study of opinion dynamics is of great interest in analyzing social phenomena. Among the different models of opinion dynamics, bounded confidence models have been studied in different contexts and shown interesting dynamics [1-3]. In [E. Kurmyshev, H.A. Ju\\'arez, and R.A. Gonz\\'alez-Silva, Phys. A 390, 16 (2011)] we proposed a new bounded confidence model and studied the self-formation of opinion in heterogeneous societies composed by agents of two psychological types, concord (C-) and partial antagonism (PA-) agents. In this work we study the influence of "leaders" on the clustering of opinions. Mixed C/PA-societies along with the pure C- and PA-society are studied. The influence of the leader's connectivity in the network, his toughness or tolerance and his opinion on the opinion dynamics is studied as a function of the initial opinion uncertainty (tolerance) of the population. Numerical results...
Directory of Open Access Journals (Sweden)
Zhili Liang
2016-04-01
Full Text Available Peptide-bound advanced glycation end-products (peptide-bound AGEs can be formed when peptides are heated with reducing saccharides. Pyrraline is the one of most commonly studied AGEs in foods, but the relative importance of the precursor peptide structure is uncertain. In the present study, model systems were prepared by heating peptides with glucose from 60 °C to 220 °C for up to 65 min, and the amounts of peptide-bound pyrraline formed were monitored to evaluate the effect of the neighboring amino acids on the peptide-bound pyrraline formation. The physico-chemical properties were introduced to explore the quantitative structure-reactivity relationships between physicochemical properties and peptide bound formation. 3-DG content in dipeptide-glucose model system was higher than that in the corresponding tripeptide-glucose model systems. Dipeptides produced higher amounts of peptide-bound pyrraline than the corresponding tripeptides. The peptide-bound pyrraline and 3-DG production were influenced by the physico-chemical properties of the side chain of amino acids adjacent to Lys in the following order: Lys-Leu/glucose > Lys-Ile/glucose > Lys-Val/ glucose > Lys-Thr/glucose > Lys-Ser/glucose > Lys-Ala/ glucose > Lys-Gly/glucose; Lys-Leu-Gly/glucose > Lys-Ile-Gly/glucose > Lys-Val-Gly/glucose > Lys-Thr-Gly/glucose > Lys-Ser-Gly/glucose > Lys-Ala-Gly/glucose > Lys-Gly-Gly/glucose. For the side chain of amino acids adjacent to Lys in dipeptides, residue volume, polarizability, molecular volume and localized electrical effect were positively related to the yield of peptide bound pyrraline, while hydrophobicity and pKb were negatively related to the yield of peptide bound pyrraline. In terms of side chain of amino acid adjacent to Lys in tripeptides, a similar result was observed, except hydrophobicity was positively related to the yield of peptide bound pyrraline.
Unitarity and Monojet Bounds on Models for DAMA, CoGeNT, and CRESST-II
Shoemaker, Ian M
2011-01-01
If dark matter interacts with quarks or gluons, the mediator of these interactions is either directly accessible at the LHC or is so heavy that its effects are encoded in contact operators. We find that the self-consistency of a contact operator description at the LHC implies bounds on the mediator scale stronger than those found from missing energy searches. This translates into spin-independent elastic scattering cross-sections at a level < 10^-40 cm^2, with clear implications for the DAMA, CoGeNT, and CRESST-II anomalies. We then carefully explore the potential of monojet searches in the light mediator limit, focusing on a Z' model with arbitrary couplings to quarks and dark matter. We find that the Tevatron data currently provides the most stringent bounds for dark matter and Z' masses below 100 GeV, and that these searches can constrain models for the DAMA, CoGeNT, and CRESST-II anomalies only if the mediator can decay to a pair of dark matter particles.
Systematic model-dependent behaviour of fusion involving weakly bound projectiles 6,7Li
International Nuclear Information System (INIS)
Many measurements on complete fusion (CF) cross section at above barrier energies involving weakly bound stable projectiles (e.g., 6Li, 7Li and 9Be) show suppression by various degrees compared to theoretical estimates as well as experimental CF cross sections of reactions involving strongly bound projectiles. However, there is no concrete picture at sub-barrier energies. The conclusions based on coupled-channels (CC) calculations using different codes (e.g., FRESCO or CCFULL) may differ as the theoretical models used to calculate fusion are not same. In a recent paper on complete fusion in 7Li+152Sm system, the fusion cross sections calculated by CCFULL and FRESCO have been shown to be different despite using same bare potential. It was observed that with the inclusion of only inelastic couplings, the results of FRESCO were much closer to the experimental data in the above barrier region, while the CCFULL results overpredict the data over the entire range. To explore the above observation in different systems involving 6,7Li as projectile, in the present work, a systematic and detailed study has been carried out by means of CC calculations using both FRESCO and CCFULL. The aim is to analyze the differences between the two models of calculations
Myers, S.; Flanagan, M.; Pasyanos, M.; Schultz, C.
2003-04-01
location accuracy and validate epicenter confidence bounds. These tests demonstrate that application of calibrated travel-time models significantly reduces location bias and results in random errors that are predicted by location confidence bounds. Research was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48 for the Office of Research and Development, NN-20, within the Office of NonProliferation and National Security, NN-1.
de Lara-Castells, María Pilar; Mitrushchenkov, Alexander O
2015-11-01
The interaction potential of molecular hydrogen physisorbed on a graphene sheet is evaluated using the ab initio-based periodic dlDF+Das scheme and its accuracy is assessed by comparing the nuclear bound-state energies supported by the H2(D2/HD)/graphite potentials with the experimental energies. The periodic dlDF+Das treatment uses DFT-based symmetry-adapted perturbation theory on surface cluster models to extract the dispersion contribution to the interaction whereas periodic dispersionless density functional (dlDF) calculations are performed to determine the dispersion-free counterpart. It is shown that the H2/graphene interaction is effectively two-dimensional (2D), with the distance from the molecule center-of-mass to the surface plane and the angle between the diatomic axis and the surface normal as the relevant degrees of freedom. The global potential minimum is found at the orthogonal orientation of the molecule with respect to the surface plane, with an equilibrium distance of 3.17 Å and a binding energy of -51.9 meV. The comparison of the binding energies shows an important improvement of our approach over the vdW-corrected DFT schemes when we are dealing with the very weak H2/surface interaction. Next, the 2D nuclear bound-state energies are calculated numerically. As a cross-validation of the interaction potential, the bound states are also determined for molecular hydrogen on the graphite surface (represented as an assembly of graphene sheets). With the largest absolute deviation being 1.7 meV, the theoretical and experimental energy levels compare very favorably. PMID:26479965
Upper Bound on $R_b$ in Two Higgs Doublet Model from Lepton Universality
Hisano, J; Murayama, H; Hisano, Junji; Kiyoura, Shingo; Murayama, Hitoshi
1997-01-01
It has been known that $R_b$ can be enhanced in the two Higgs doublet model if $\\tan \\beta$ is large. We point out that a similar enhancement in possibility. We obtain a 95% CL upper bound $\\Delta R_b/R_{b} < 0.73%$ in this model for the $\\overline{MS}$ mass $m_{b} (m_{Z}) = 3.0$ GeV. The 1996 world average is $\\Delta R_{b}/R_{b}$ = $0.97% \\pm 0.51%$. We used the $m_{b}(m_{Z})$ to determine the bottom Yukawa coupling instead of $m_b(m_{b})$ unlike in previous analyses, and also an improved experimental test of the lepton universality in $Z$ decay, which made our results qualitatively different.
From superWIMPs to decaying dark matter. Models, bounds and indirect searches
Energy Technology Data Exchange (ETDEWEB)
Weniger, Christoph
2010-06-15
Despite lots of observational and theoretical efforts, the particle nature of dark matter remains unknown. Beyond the paradigmatic WIMPs (Weakly Interacting Massive Particles), many theoretically well motivated models exist where dark matter interacts much more weakly than electroweak with Standard Model particles. In this case new phenomena occur, like the decay of dark matter or the interference with the standard cosmology of the early Universe. In this thesis we study some of these aspects of superweakly coupled dark matter in general, and in the special case of hidden U(1){sub X} gauginos that kinetically mix with hypercharge. There, we will assume that the gauge group remains unbroken, similar to the Standard Model U(1){sub em}. We study different kinds of cosmological bounds, including bounds from thermal overproduction, from primordial nucleosynthesis and from structure formation. Furthermore, we study the possible cosmic-ray signatures predicted by this scenario, with emphasis on the electron and positron channel in light of the recent observations by PAMELA and Fermi LAT. Moreover we study the cosmic-ray signatures of decaying dark matter independently of concrete particle-physics models. In particular we analyze in how far the rise in the positron fraction above 10 GeV, as observed by PAMELA, can be explained by dark matter decay. Lastly, we concentrate on related predictions for gamma-ray observations with the Fermi LAT, and propose to use the dipole-like anisotropy of the prompt gamma-ray dark matter signal to distinguish exotic dark matter contributions from the extragalactic gamma-ray background. (orig.)
Checking Security Policy Compliance
Gowadia, Vaibhav; Kudo, Michiharu
2008-01-01
Ensuring compliance of organizations to federal regulations is a growing concern. This paper presents a framework and methods to verify whether an implemented low-level security policy is compliant to a high-level security policy. Our compliance checking framework is based on organizational and security metadata to support refinement of high-level concepts to implementation specific instances. Our work uses the results of refinement calculus to express valid refinement patterns and their properties. Intuitively, a low-level security policy is compliant to a high-level security policy if there is a valid refinement path from the high-level security policy to the low-level security policy. Our model is capable of detecting violations of security policies, failures to meet obligations, and capability and modal conflicts.
Charge–mass ratio bound and optimization in the Parikh–Wilczek tunneling model of Hawking radiation
International Nuclear Information System (INIS)
In this Letter, we study the mutual information hidden in the Parikh–Wilczek tunneling model of Hawking radiation for Reissner–Nordström black holes. We argue that the condition of nonnegativity of mutual information suggests bound(s) for charge–mass ratio of emitted particles. We further view the radiation as an optimization process and discuss its effect on time evolution of a charged black hole.
Charge–mass ratio bound and optimization in the Parikh–Wilczek tunneling model of Hawking radiation
Energy Technology Data Exchange (ETDEWEB)
Kim, Kyung Kiu, E-mail: kimkyungkiu@gmail.com [Department of Physics, Kyung Hee University, Seoul (Korea, Republic of); Center for Quantum Space Time, Sogang University, Seoul (Korea, Republic of); Department of Physics and Photon Science, School of Physics and Chemistry, GIST (Korea, Republic of); Wen, Wen-Yu, E-mail: steve.wen@gmail.com [Department of Physics and Center for High Energy Physics, Chung Yuan Christian University, Chung Li City, Taiwan (China); Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, Taipei 106, Taiwan (China)
2014-04-04
In this Letter, we study the mutual information hidden in the Parikh–Wilczek tunneling model of Hawking radiation for Reissner–Nordström black holes. We argue that the condition of nonnegativity of mutual information suggests bound(s) for charge–mass ratio of emitted particles. We further view the radiation as an optimization process and discuss its effect on time evolution of a charged black hole.
Self-bound quark matter in the NJL model revisited: from schematic droplets to solitonic lasagne
Buballa, Michael
2012-01-01
The existence and the properties of self-bound quark matter in the NJL model at zero temperature are investigated in mean-field approximation, focusing on inhomogeneous structures with one-dimensional spatial modulations. It is found that the most stable homogeneous solutions which have previously been interpreted as schematic quark droplets are unstable against formation of a one-dimensional soliton-antisoliton lattice. The solitons repel each other, so that the minimal energy per quark is realized in the single-soliton limit. The properties of the solitons and their interactions are discussed in detail, and the effect of vector interactions is estimated. The results may be relevant for the dynamics of expanding quark matter.
Pattern Selection and Super-patterns in the Bounded Confidence Model
Ben-Naim, E
2015-01-01
We study pattern formation in the bounded confidence model of opinion dynamics. In this random process, opinion is quantified by a single variable. Two agents may interact and reach a fair compromise, but only if their difference of opinion falls below a fixed threshold. Starting from a uniform distribution of opinions with compact support, a traveling wave forms and it propagates from the domain boundary into the unstable uniform state. Consequently, the system reaches a steady state with isolated clusters that are separated by distance larger than the interaction range. These clusters form a quasi-periodic pattern where the sizes of the clusters and the separations between them are nearly constant. We obtain analytically the average separation between clusters L. Interestingly, there are also very small quasi-periodic modulations in the size of the clusters. The spatial periods of these modulations are a series of integers that follow from the continued fraction representation of the irrational average sepa...
Wallace, Rodrick
2015-08-01
The stabilization of human cognition via feedback from embedding social and cultural contexts is a dynamic process deeply intertwined with it, constituting, in a sense, the riverbanks directing the flow of a stream of generalized consciousness at different scales: Cultural norms and social interaction are synergistic with individual and group cognition and their disorders. A canonical failure mode in atomistic cultures is found to be a 'ground state' collapse well represented by atomistic models of economic interaction that are increasingly characterized as divorced from reality by heterodox economists. That is, high rates of psychopathic and antisocial personality disorder and obsessive compulsive disorder emerge as culture-bound syndromes particular to Western or Westernizing societies, or to those undergoing social disintegration. PMID:26003470
Uncertainty in Cross Orthogonality Checks
Matsumura, Yuichi
Finite element structural dynamic models are typically validated using data obtained from a modal testing. Although it is known that test variability may affect the verification, the test variability is typically ignored in the verification process. This paper describes the sensitivities of cross orthogonality check to the test variability. The cross orthogonality check is one of correlation techniques which is gaining acceptance in the structural dynamics community, because of its improved accuracy over the standard modal assurance criterion. Then an uncertainty index of the cross orthogonality check is proposed based on the fact that the sensitivities are much dependent on sensor placement. The results of some artificially generated test cases are presented to demonstrate the applicability of the proposed approach.
Buboltz, Jeffrey T; Kamburov, Dobromir
2007-01-01
The two most common metrics used to assess Forster resonance energy transfer (FRET) between fluorophores are (i) acceptor-quenching of donor fluorescence, E(a.k.a. transfer efficiency); and (ii) donor-excited acceptor fluorescence, F(A-Dex). It is still true that E is more widely used, but F(A-Dex) has been gaining in popularity among experimentalists for practical reasons. It is therefore notable that while a number of theoretical models have long been available for interpreting measurements of E, the same cannot be said for F(A-Dex). Here, for the special case of membrane-bound fluorophores, we present a substantial body of experimental evidence that justifies the use of a simple Stern-Volmer approach when modeling the concentration dependence of F(A-Dex) under commonly encountered experimental conditions. Moreover, the approach seems equally successful in modeling the acceptor-dependence of E under the same conditions, so we have been able to make a close comparison between our simple Stern-Volmer treatmen...
Structural model of nicotinic acetylcholine receptor isotypes bound to acetylcholine and nicotine
Directory of Open Access Journals (Sweden)
Abagyan Ruben
2002-01-01
Full Text Available Abstract Background Nicotine is a psychoactive drug presenting a diverse array of biological activities, some positive, such as enhancement of cognitive performances, others negative, such as addiction liability. Ligands that discriminate between the different isotypes of nicotinic acetylcholine receptors (nAChRs could present improved pharmacology and toxicity profile. Results Based on the recent crystal structure of a soluble acetylcholine binding protein from snails, we have built atomic models of acetylcholine and nicotine bound to the pocket of four different human nAChR subtypes. The structures of the docked ligands correlate with available biochemical data, and reveal that the determinants for isotype selectivity are relying essentially on four residues, providing diversity of the ligand binding pocket both in terms of Van der Waals boundary, and electrostatic potential. We used our models to screen in silico a large compound database and identify a new ligand candidate that could display subtype selectivity. Conclusion The nAChR-agonist models should be useful for the design of nAChR agonists with diverse specificity profiles.
Das, Arindam; Oda, Satsuki; Okada, Nobuchika; Takahashi, Dai-suke
2016-06-01
We consider the minimal U(1 ) ' extension of the standard model (SM) with the classically conformal invariance, where an anomaly-free U(1 ) ' gauge symmetry is introduced along with three generations of right-handed neutrinos and a U(1 ) ' Higgs field. Since the classically conformal symmetry forbids all dimensional parameters in the model, the U(1 ) ' gauge symmetry is broken by the Coleman-Weinberg mechanism, generating the mass terms of the U(1 ) ' gauge boson (Z' boson) and the right-handed neutrinos. Through a mixing quartic coupling between the U(1 ) ' Higgs field and the SM Higgs doublet field, the radiative U(1 ) ' gauge symmetry breaking also triggers the breaking of the electroweak symmetry. In this model context, we first investigate the electroweak vacuum instability problem in the SM. Employing the renormalization group equations at the two-loop level and the central values for the world average masses of the top quark (mt=173.34 GeV ) and the Higgs boson (mh=125.09 GeV ), we perform parameter scans to identify the parameter region for resolving the electroweak vacuum instability problem. Next we interpret the recent ATLAS and CMS search limits at the LHC Run-2 for the sequential Z' boson to constrain the parameter region in our model. Combining the constraints from the electroweak vacuum stability and the LHC Run-2 results, we find a bound on the Z' boson mass as mZ'≳3.5 TeV . We also calculate self-energy corrections to the SM Higgs doublet field through the heavy states, the right-handed neutrinos and the Z' boson, and find the naturalness bound as mZ'≲7 TeV , in order to reproduce the right electroweak scale for the fine-tuning level better than 10%. The resultant mass range of 3.5 TeV ≲mZ'≲7 TeV will be explored at the LHC Run-2 in the near future.
Asynchronous Bounded Expected Delay Networks
Bakhshi, Rena; Endrullis, Jörg; Fokkink, Wan; Pang, Jun
2010-01-01
The commonly used asynchronous bounded delay (ABD) network models assume a fixed bound on message delay. We propose a probabilistic network model, called asynchronous bounded expected delay (ABE) model. Instead of a strict bound, the ABE model requires only a bound on the expected message delay. While the conditions of ABD networks restrict the set of possible executions, in ABE networks all asynchronous executions are possible, but executions with extremely long delays are less probable. In ...
40 CFR 86.327-79 - Quench checks; NOX analyzer.
2010-07-01
... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Quench checks; NOX analyzer. 86.327-79... Quench checks; NOX analyzer. (a) Perform the reaction chamber quench check for each model of high vacuum... capillary, and if used, dilution capillary. (c) Quench check as follows: (1) Calibrate the NOX analyzer...
Left Ventricular Finite Element Model Bounded by a Systemic Circulation Model
Veress, A. I.; Raymond, G.M.; Gullberg, G. T.; Bassingthwaighte, J.B.
2013-01-01
A series of models were developed in which a circulatory system model was coupled to an existing series of finite element (FE) models of the left ventricle (LV). The circulatory models were used to provide realistic boundary conditions for the LV models. This was developed for the JSim analysis package and was composed of a systemic arterial, capillary, and venous system in a closed loop with a varying elastance LV and left atria to provide the driving pressures and flows matching those of th...
On Possible S-Wave Bound States for an N-(N) System Within a Constituent Quark Model
Institute of Scientific and Technical Information of China (English)
CHANG Chao-Hsi; PANG Hou-Rong
2005-01-01
We try to apply a constituent quark model (a variety chiral constituent quark model) and the resonating group approach for the multi-quark problems to compute the effective potential between the NN- in S-wave (the quarks in the nucleons N and N-, and the two nucleons relatively as well, are in S wave) so as to see the possibility if there may be a tight bound state of six quarks as indicated by a strong enhancement at threshold of pp- in J/ψ and B decays. The effective potential which we obtain in terms of the model and approach shows if the experimental enhancement is really caused by a tight S-wave bound state of six quarks, then the quantum number of the bound state is very likely to be I = 1, JPC= 0-+.
Leung, Ming Lam; Zhang, Shengyu
2011-01-01
We study the communication complexity of symmetric XOR functions, namely functions $f: \\{0,1\\}^n \\times \\{0,1\\}^n \\rightarrow \\{0,1\\}$ that can be formulated as $f(x,y)=D(|x\\oplus y|)$ for some predicate $D: \\{0,1,...,n\\} \\rightarrow \\{0,1\\}$, where $|x\\oplus y|$ is the Hamming weight of the bitwise XOR of $x$ and $y$. We give a public-coin randomized protocol in the Simultaneous Message Passing (SMP) model, with the communication cost matching the known lower bound for the \\emph{quantum} and \\emph{two-way} model up to a logarithm factor. As a corollary, this closes a quadratic gap between quantum lower bound and randomized upper bound for the one-way model, answering an open question raised in Shi and Zhang \\cite{SZ09}.
Anonymity control in electronic check systems
Institute of Scientific and Technical Information of China (English)
Ma Chunguang; Yang Yixian; Hu Zhengming
2005-01-01
Electronic check systems, as one of electronic payment systems, are more desirable than other electronic cash systems. In the system, only a single check is used to pay any price that is not more than the face value. The main problem in check systems is to design an efficient refund mechanism that makes refund checks undistinguished from initial checks during payment and deposit. The problem of anonymity control also called fairness is also an important issue in check systems. All check systems yet are unconditional anonymity that opens the door to misuse for crime such as laundering and blackmailing. In this paper, the notion of anonymity revocation is introduced to electronic check system for the first time, and a model of fair electronic check system is proposed. An efficient fair online electronic check system with reusable refund is presented. In the system, a passive trustee is employed to revoke the anonymity of un-honest users. Moreover, the system solves the reusability problem of refunds thanks to the RSA-based partially signature. The system is efficient and meets all basic security requirements.
Saric, Dragomir
2006-01-01
We give a short proof of the fact that bounded earthquakes of the unit disk induce quasisymmetric maps of the unit circle. By a similar method, we show that symmetric maps are induced by bounded earthquakes with asymptotically trivial measures.
McNicholl, Patrick J.; Crabtree, Peter N.
2014-09-01
Applications of stellar occultation by solar system objects have a long history for determining universal time, detecting binary stars, and providing estimates of sizes of asteroids and minor planets. More recently, extension of this last application has been proposed as a technique to provide information (if not complete shadow images) of geosynchronous satellites. Diffraction has long been recognized as a source of distortion for such occultation measurements, and models subsequently developed to compensate for this degradation. Typically these models employ a knife-edge assumption for the obscuring body. In this preliminary study, we report on the fundamental limitations of knife-edge position estimates due to shot noise in an otherwise idealized measurement. In particular, we address the statistical bounds, both Cramér- Rao and Hammersley-Chapman-Robbins, on the uncertainty in the knife-edge position measurement, as well as the performance of the maximum-likelihood estimator. Results are presented as a function of both stellar magnitude and sensor passband; the limiting case of infinite resolving power is also explored.
... https://www.nlm.nih.gov/medlineplus/healthchecktools.html Health Check Tools To use the sharing features on ... Schedule (Centers for Disease Control and Prevention) Children's Health Body Mass Index: Calculator for Child and Teen ( ...
... Materials The Healthy Heart Handbook for Women Check it Out Tests That Can Help Protect Your Heart ... years, or more often if your doctor recommends it. Other Tests There also are several tests that ...
DEFF Research Database (Denmark)
Henriksen, Jørgen; Nielsen, Mette Benedicte Olaf; Madsen, Jørgen;
2009-01-01
This check list, financed by DanChurchAid, highlights all issues should be carefully investigated before investing in distribution of goats and in interventions to assist poor rural communities to improve their livelihood through goat production.......This check list, financed by DanChurchAid, highlights all issues should be carefully investigated before investing in distribution of goats and in interventions to assist poor rural communities to improve their livelihood through goat production....
RG running in a minimal UED model in light of recent LHC Higgs mass bounds
International Nuclear Information System (INIS)
We study how the recent ATLAS and CMS Higgs mass bounds affect the renormalization group running of the physical parameters in universal extra dimensions. Using the running of the Higgs self-coupling constant, we derive bounds on the cutoff scale of the extra-dimensional theory itself. We show that the running of physical parameters, such as the fermion masses and the CKM mixing matrix, is significantly restricted by these bounds. In particular, we find that the running of the gauge couplings cannot be sufficient to allow gauge unification at the cutoff scale.
Super-Grid Modeling of the Elastic Wave Equation in Semi-Bounded Domains
Energy Technology Data Exchange (ETDEWEB)
Petersson, N. Anders; Sjögreen, Björn
2014-10-01
We develop a super-grid modeling technique for solving the elastic wave equation in semi-bounded two- and three-dimensional spatial domains. In this method, waves are slowed down and dissipated in sponge layers near the far-field boundaries. Mathematically, this is equivalent to a coordinate mapping that transforms a very large physical domain to a significantly smaller computational domain, where the elastic wave equation is solved numerically on a regular grid. To damp out waves that become poorly resolved because of the coordinate mapping, a high order artificial dissipation operator is added in layers near the boundaries of the computational domain. We prove by energy estimates that the super-grid modeling leads to a stable numerical method with decreasing energy, which is valid for heterogeneous material properties and a free surface boundary condition on one side of the domain. Our spatial discretization is based on a fourth order accurate finite difference method, which satisfies the principle of summation by parts. We show that the discrete energy estimate holds also when a centered finite difference stencil is combined with homogeneous Dirichlet conditions at several ghost points outside of the far-field boundaries. Therefore, the coefficients in the finite difference stencils need only be boundary modified near the free surface. This allows for improved computational efficiency and significant simplifications of the implementation of the proposed method in multi-dimensional domains. Numerical experiments in three space dimensions show that the modeling error from truncating the domain can be made very small by choosing a sufficiently wide super-grid damping layer. The numerical accuracy is first evaluated against analytical solutions of Lamb’s problem, where fourth order accuracy is observed with a sixth order artificial dissipation. We then use successive grid refinements to study the numerical accuracy in the more
Neutron scattering from elemental indium, the optical model, and the bound-state potential
International Nuclear Information System (INIS)
Neutron differential elastic-scattering cross sections of elemental indium are measured from 4.5 to 10 MeV at incident-energy intervals of ∼500 keV. Seventy or more differential values are obtained at each incident energy, distributed between ∼18 degree and 160 degree. These experimental results are combined with lower-energy values previously obtained at this laboratory, and with 11 and 14 MeV results in the literature, to form a comprehensive elastic-scattering database extending from ∼1.5 to 14 MeV. These data are interpreted in terms of a conventional spherical optical model. The resulting potential is extrapolated to the bound-state regime. It is shown that in the middle of the 50--82 neutron shell, the potential derived from the scattering results adequately describes the binding energies of article states, but does not do well for hole states. The latter shortcoming is attributed to the holes states having occupational probabilities sufficiently different from unity, so that the exclusion principle become a factor, and to the rearrangement of the neutron core. 68 refs
THE PERIODIC CAPACITATED ARC ROUTING PROBLEM LINEAR PROGRAMMING MODEL,METAHEURISTIC AND LOWER BOUNDS
Institute of Scientific and Technical Information of China (English)
Feng CHU; Nacima LABADI; Christian PRINS
2004-01-01
The Periodic Capacitated Arc Routing Problem (PCARP) generalizes the well known NP-hard Capacitated Arc Routing Problem (CARP) by extending the single period to multi-period horizon.The Capacitated Arc Routing Problem (CARP) is defined on an undirected network in which a fleet of identical vehicles is based at a depot node. A subset of edges, called tasks, must be serviced by a vehicle. The CARP consists of determining a set of feasible vehicle trips that minimizes the total cost of traversed edges. The PCARP involves the assignment of tasks to periods and the determination of vehicles trips in each period, to minimize the total cost on the whole horizon. This new problem arises in various real life applications such as waste collection, mail delivery, etc. In this paper, a new linear programming model and preliminary lower bounds based on graph transformation are proposed. A meta-heuristic approach - Scatter Search (SS) is developed for the PCARP and evaluated on a large variety of instances.
Physical Uncertainty Bounds (PUB)
Energy Technology Data Exchange (ETDEWEB)
Vaughan, Diane Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Preston, Dean L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2015-03-19
This paper introduces and motivates the need for a new methodology for determining upper bounds on the uncertainties in simulations of engineered systems due to limited fidelity in the composite continuum-level physics models needed to simulate the systems. We show that traditional uncertainty quantification methods provide, at best, a lower bound on this uncertainty. We propose to obtain bounds on the simulation uncertainties by first determining bounds on the physical quantities or processes relevant to system performance. By bounding these physics processes, as opposed to carrying out statistical analyses of the parameter sets of specific physics models or simply switching out the available physics models, one can obtain upper bounds on the uncertainties in simulated quantities of interest.
Ackermann error checking method based on CATIA Parametric-modeling%基于 CATIA 参数化建模校核 Ackermann误差的方法
Institute of Scientific and Technical Information of China (English)
杨洪云; 胡伟; 陈琪; 施正生
2016-01-01
介绍了 Ackermann 误差概念和传统校核方法的局限性，提出采用 CATIA 参数化建模方式，建立全空间转向机构硬点-骨架模型，依靠 CATIA 参数化驱动功能，通过改变参数得到非常精确的 Ackermann 误差，并且利用参数与设计表关联，快速得到所有车型转向系统的骨架模型，实现了高效、准确校核大量车型 Ackermann 误差的目的。%This article presents the concept of Ackermann error and the defects of traditional checking method , building full-geometrical steering hard-point model by the parametric- modeling method to obtain the precise Ackermann error with the function of parameter-driven, realized the goal of checking Ackermann error of a mount of vehicles with high efficiency and precision utilizing the Design table to build the skeleton model of steering system of all vehicles.
Directory of Open Access Journals (Sweden)
Hylander Ingrid
2010-07-01
Full Text Available Abstract Background Worldwide, multicultural interaction within health care seems to be challenging and problematic. This is also true among Primary Child Health Care nurses (PCHC nurses in the Swedish Primary Child Health Care services (PCHC services. Therefore, there was a need to investigate the parents' perspective in-depth. Aim The aim of the study was to construct a theoretical model that could promote further understanding of the variety of experiences of parents of foreign origin regarding their interaction with the PCHC nurses at PCHC services. Method The study used Grounded Theory Methodology. Twenty-one parents of foreign origin in contact with PCHC servicies were interviewed. Results In our study parents were watchfully checking rapport, i.e. if they could perceive sympathy and understanding from the PCHC nurses. This was done by checking the nurse's demeanour and signs of judgement. From these interviews we created a theoretical model illustrating the interactive process between parents and PCHC nurses. Conclusion We found it to be of utmost importance for parents to be certain that it was possible to establish rapport with the PCHC nurse. If not, disruptions in the child's attendance at PCHC services could result. PCHC nurses can use the theoretical model resulting from this study as a basis for understanding parents, avoiding a demeanour and judgements that may cause misunderstandings thus promoting high-quality interaction in PCHC services.
Ackermann error checking method based on CATIA Parametric-modeling%基于 CATIA 参数化建模校核 Ackermann误差的方法
Institute of Scientific and Technical Information of China (English)
杨洪云; 胡伟; 陈琪; 施正生
2016-01-01
This article presents the concept of Ackermann error and the defects of traditional checking method , building full-geometrical steering hard-point model by the parametric- modeling method to obtain the precise Ackermann error with the function of parameter-driven, realized the goal of checking Ackermann error of a mount of vehicles with high efficiency and precision utilizing the Design table to build the skeleton model of steering system of all vehicles.%介绍了 Ackermann 误差概念和传统校核方法的局限性，提出采用 CATIA 参数化建模方式，建立全空间转向机构硬点-骨架模型，依靠 CATIA 参数化驱动功能，通过改变参数得到非常精确的 Ackermann 误差，并且利用参数与设计表关联，快速得到所有车型转向系统的骨架模型，实现了高效、准确校核大量车型 Ackermann 误差的目的。
Han, Hyojung; Rojewski, Jay W.
2015-01-01
A Korean national database, the High School Graduates Occupational Mobility Survey, was used to examine the influence of perceived social supports (family and school) and career adaptability on the subsequent job satisfaction of work-bound adolescents 4 months after their transition from high school to work. Structural equation modeling analysis…
Xie, Rui-Hua; Gong, Jiangbin
2005-01-01
Based on a simplest molecular orbital theory of H$_{2}^{+}$, a three-parameter model potential function is proposed to describe ground-state diatomic systems with closed-shell and/or S-type valence-shell constituents over a significantly wide range of internuclear distances. More than 200 weakly and strongly bound diatomics have been studied, including neutral and singly-charged diatomics (e.g., H$_{2}$, Li$_{2}$, LiH, Cd$_{2}$, Na$_{2}^{+}$, and RbH$^{-}$), long-range bound diatomics (e.g., ...
Yan, Zheng; Wang, Jun
2014-03-01
This paper presents a neural network approach to robust model predictive control (MPC) for constrained discrete-time nonlinear systems with unmodeled dynamics affected by bounded uncertainties. The exact nonlinear model of underlying process is not precisely known, but a partially known nominal model is available. This partially known nonlinear model is first decomposed to an affine term plus an unknown high-order term via Jacobian linearization. The linearization residue combined with unmodeled dynamics is then modeled using an extreme learning machine via supervised learning. The minimax methodology is exploited to deal with bounded uncertainties. The minimax optimization problem is reformulated as a convex minimization problem and is iteratively solved by a two-layer recurrent neural network. The proposed neurodynamic approach to nonlinear MPC improves the computational efficiency and sheds a light for real-time implementability of MPC technology. Simulation results are provided to substantiate the effectiveness and characteristics of the proposed approach. PMID:24807443
Wingerter, Akin
2011-01-01
We revisit the stability and triviality bounds on the Higgs boson mass in the context of the Standard Model with three and four generations (SM3 and SM4, respectively). In light of the recent results from LHC the triviality bound in the SM3 has now become obsolete, and the stability bound implies for a Higgs mass of e.g. mH=115 GeV the onset of new physics before 650 TeV, whereas there are no limits for mH>133 GeV. For the SM4, the stability and triviality curves intersect and bound a finite region. As a consequence, the fourth generation fermions place stringent theoretical limits on the Higgs mass, and there is a maximal scale beyond which the theory cannot be perturbatively valid. We find that the Higgs mass cannot exceed 700 GeV for any values of the fourth generation fermion masses. Turning the argument around, the absence of a Higgs signal for mH<600 GeV excludes a fourth generation with quark masses below 300 GeV and lepton masses below 350 GeV. In particular, the quark bounds also hold for the smal...
International Nuclear Information System (INIS)
In support of the NRC Nuclear Plant Aging Research (NPAR) program, the Oak Ridge National Laboratory (ORNL) has carried out an assessment of several check value diagnostic monitoring methods, in particular, those based on measurements of acoustic emission, ultrasonics, and magnetic flux. The evaluations have focussed on the capabilities of each method to provide information useful in determining check valve aging and service wear effects, check valve failures, and undesirable operating modes. This paper describes the benefits and limitations associated with each method and includes recent laboratory and field test data, including data obtained from the vendors who recently participated in a comprehensive series of tests directed by a nuclear industry users group. In addition, as part of the ORNL Advanced Diagnostic Engineering Research and Development Center (ADEC), two novel nonintrusive monitoring methods were developed that provide several unique capabilities. These methods, based on external ac- an dc-magnetic monitoring are also described. None of the examined methods could, by themselves, monitor both the instantaneous position and motion of check valve internals and valve leakage; however, the combination of acoustic emission monitoring with one of the other methods provides the means to determine vital check valve operational information
Sociable interface-based model checking for Web applications%基于交际接口的Web应用模型检验
Institute of Scientific and Technical Information of China (English)
李决龙; 李亮; 邢建春; 杨启亮
2011-01-01
为了验证Web应用的质量,首次采用了基于交际接口及其工具TICC的建筑智能化系统Web应用验证方法,通过一个简单的能源管理Web应用系统实例说明了整个建模、构件模块组合验证和系统性质验证过程.结果表明验证能够顺利实现,因而该方法是一种合适的Web应用验证方法.%In order to verify Web applications' quality, the paper firstly adopted the methodology based on sociable interface and its tool TICC to check Web applications in the intelligent building systems, used a simple case of energy sources management Web application system to illustrate the whole process of modeling, component composing verification and characteristic model checking.The result shows that verification is done successfully, so it is an appropriate verification method for Web applications.
Energy Technology Data Exchange (ETDEWEB)
Montano, Joshua Daniel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2015-03-23
Coordinate Measuring Machines (CMM) are widely used in industry, throughout the Nuclear Weapons Complex and at Los Alamos National Laboratory (LANL) to verify part conformance to design definition. Calibration cycles for CMMs at LANL are predominantly one year in length. Unfortunately, several nonconformance reports have been generated to document the discovery of a certified machine found out of tolerance during a calibration closeout. In an effort to reduce risk to product quality two solutions were proposed – shorten the calibration cycle which could be costly, or perform an interim check to monitor the machine’s performance between cycles. The CMM interim check discussed makes use of Renishaw’s Machine Checking Gauge. This off-the-shelf product simulates a large sphere within a CMM’s measurement volume and allows for error estimation. Data was gathered, analyzed, and simulated from seven machines in seventeen different configurations to create statistical process control run charts for on-the-floor monitoring.
Directory of Open Access Journals (Sweden)
Estoup Arnaud
2010-07-01
Full Text Available Abstract Background Approximate Bayesian computation (ABC is a recent flexible class of Monte-Carlo algorithms increasingly used to make model-based inference on complex evolutionary scenarios that have acted on natural populations. The software DIYABC offers a user-friendly interface allowing non-expert users to consider population histories involving any combination of population divergences, admixtures and population size changes. We here describe and illustrate new developments of this software that mainly include (i inference from DNA sequence data in addition or separately to microsatellite data, (ii the possibility to analyze five categories of loci considering balanced or non balanced sex ratios: autosomal diploid, autosomal haploid, X-linked, Y-linked and mitochondrial, and (iii the possibility to perform model checking computation to assess the "goodness-of-fit" of a model, a feature of ABC analysis that has been so far neglected. Results We used controlled simulated data sets generated under evolutionary scenarios involving various divergence and admixture events to evaluate the effect of mixing autosomal microsatellite, mtDNA and/or nuclear autosomal DNA sequence data on inferences. This evaluation included the comparison of competing scenarios and the quantification of their relative support, and the estimation of parameter posterior distributions under a given scenario. We also considered a set of scenarios often compared when making ABC inferences on the routes of introduction of invasive species to illustrate the interest of the new model checking option of DIYABC to assess model misfit. Conclusions Our new developments of the integrated software DIYABC should be particularly useful to make inference on complex evolutionary scenarios involving both recent and ancient historical events and using various types of molecular markers in diploid or haploid organisms. They offer a handy way for non-expert users to achieve model checking
Causal Entropy Bound for a Spacelike Region
Brustein, R.; Veneziano, G.
2000-06-01
The identification of a causal-connection scale motivates us to propose a new covariant bound on entropy within a generic spacelike region. This ``causal entropy bound,'' scaling as EV, and thus lying around the geometric mean of Bekenstein's S/ER and holographic S/A bounds, is checked in various ``critical'' situations. In the case of limited gravity, Bekenstein's bound is the strongest while naive holography is the weakest. In the case of strong gravity, our bound and Bousso's holographic bound are stronger than Bekenstein's, while naive holography is too tight, and hence typically wrong.
Hoyer, Paul
2016-01-01
Even a first approximation of bound states requires contributions of all powers in the coupling. This means that the concept of "lowest order bound state" needs to be defined. In these lectures I discuss the "Born" (no loop, lowest order in $\\hbar$) approximation. Born level states are bound by gauge fields which satisfy the classical field equations. As a check of the method, Positronium states of any momentum are determined as eigenstates of the QED Hamiltonian, quantized at equal time. Analogously, states bound by a strong external field $A^\\mu(\\xv)$ are found as eigenstates of the Dirac Hamiltonian. Their Fock states have dynamically created $e^+e^-$ pairs, whose distribution is determined by the Dirac wave function. The linear potential of $D=1+1$ dimensions confines electrons but repels positrons. As a result, the mass spectrum is continuous and the wave functions have features of both bound states and plane waves. The classical solutions of Gauss' law are explored for hadrons in QCD. A non-vanishing bo...
Prediction Interval Development for Wind-Tunnel Balance Check-Loading
Landman, Drew; Toro, Kenneth G.; Commo, Sean A.; Lynn, Keith C.
2014-01-01
Results from the Facility Analysis Verification and Operational Reliability project revealed a critical gap in capability in ground-based aeronautics research applications. Without a standardized process for check-loading the wind-tunnel balance or the model system, the quality of the aerodynamic force data collected varied significantly between facilities. A prediction interval is required in order to confirm a check-loading. The prediction interval provides an expected upper and lower bound on balance load prediction at a given confidence level. A method has been developed which accounts for sources of variability due to calibration and check-load application. The prediction interval method of calculation and a case study demonstrating its use is provided. Validation of the methods is demonstrated for the case study based on the probability of capture of confirmation points.
International Nuclear Information System (INIS)
We revisit the stability and triviality bounds on the Higgs boson mass in the context of the standard model with three and four generations (SM3 and SM4, respectively). In light of the recent results from LHC, the triviality bound in the SM3 has now become obsolete, and the stability bound implies for a Higgs mass of e.g. mH=115 GeV the onset of new physics before Λ=650 TeV, whereas there are no limits for mH≥133 GeV. For the SM4, the stability and triviality curves intersect and bound a finite region. As a consequence, the fourth generation fermions place stringent theoretical limits on the Higgs mass, and there is a maximal scale beyond which the theory cannot be perturbatively valid. We find that the Higgs mass cannot exceed 700 GeV for any values of the fourth generation fermion masses. Turning the argument around, the absence of a Higgs signal for mH≤600 GeV excludes a fourth generation with quark masses below 300 GeV and lepton masses below 350 GeV. In particular, the quark bounds also hold for the small mixing scenarios for which the direct limits from Tevatron and LHC are not applicable, and the lepton bounds we obtain are stronger than the collider limits. If a Higgs boson lighter than 700 GeV is not observed, a fourth generation of chiral fermions with perturbative Yukawa couplings will be conclusively excluded for the full range of parameters.
On devising Boussinesq-type models with bounded eigenspectra: One horizontal dimension
DEFF Research Database (Denmark)
Eskilsson, Claes; Engsig-Karup, Allan Peter
2014-01-01
The propagation of water waves in the nearshore region can be described by depth-integrated Boussinesq-type equations. The dispersive and nonlinear characteristics of the equations are governed by tuneable parameters. We examine the associated linear eigenproblem both analytically and numerically...... requires Δt∝p−2. We derive and present conditions on the parameters under which implicitly-implicit Boussinesq-type equations will exhibit bounded eigenspectra. Two new bounded versions having comparable nonlinear and dispersive properties as the equations of Nwogu (1993) and Schäffer and Madsen (1995) are...
Atmospheric inverse modeling with known physical bounds: an example from trace gas emissions
Directory of Open Access Journals (Sweden)
S. M. Miller
2014-02-01
the relative merits of each. This paper investigates the applicability of several approaches to bounded inverse problems. A common method of data transformations is found to unrealistically skew estimates for the examined example application. The method of Lagrange multipliers and two Markov chain Monte Carlo (MCMC methods yield more realistic and accurate results. In general, the examined MCMC approaches produce the most realistic result but can require substantial computational time. Lagrange multipliers offer an appealing option for large, computationally intensive problems when exact uncertainty bounds are less central to the analysis. A synthetic data inversion of US anthropogenic methane emissions illustrates the strengths and weaknesses of each approach.
Bound states of the $\\phi^4$ model via the Non-Perturbative Renormalization Group
Rose, F; Leonard, F; Delamotte, B
2016-01-01
Using the nonperturbative renormalization group, we study the existence of bound states in the symmetry-broken phase of the scalar $\\phi^4$ theory in all dimensions between two and four and as a function of the temperature. The accurate description of the momentum dependence of the two-point function, required to get the spectrum of the theory, is provided by means of the Blaizot--M\\'endez-Galain--Wschebor approximation scheme. We confirm the existence of a bound state in dimension three, with a mass within 1% of previous Monte-Carlo and numerical diagonalization values.
... by Mail Close www.diabetes.org > Living With Diabetes > Treatment and Care > Blood Glucose Testing Share: Print Page Text Size: ... glucose-and-a1c, In this section Living With Diabetes Treatment and Care Blood Glucose Testing Checking Your Blood Glucose A1C ...
Semantic rule-checking for regulation compliance checking: an overview of strategies and approaches
Pauwels, Pieter; Zhang, Sijie
2015-01-01
As more and more architectural design and construction data is represented in the Resource Description Framework (RDF) data model, it makes sense to take advantage of the underlying logical basis of RDF and realise a semantic rule-checking process as it is currently not available in architectural design and construction industry. Such a semantic rule-checking process would be of considerable value to regulation compliance checking procedures, because the additional logical basis would (1) all...
Directory of Open Access Journals (Sweden)
Ümit Baran Metin
2015-07-01
Full Text Available Soldiering is defined as engaging behaviourally or cognitively into non-work-related activities during working hours with no intention of harming the employer, co-workers, and/or clients. The present study will investigate this phenomenon using the Job-Demands Resources Model. The proposed model will consider the influence of job demands and resources on soldiering, as well as the relationship of soldiering with employee wellbeing and performance. The data, collected via online questionnaires across seven European countries, will be analysed using structural equation modelling in order to explore the goodness-of-fit of the proposed model as well as its potential cross cultural variations.
Bounded Gaussian process regression
DEFF Research Database (Denmark)
Jensen, Bjørn Sand; Nielsen, Jens Brehm; Larsen, Jan
2013-01-01
We extend the Gaussian process (GP) framework for bounded regression by introducing two bounded likelihood functions that model the noise on the dependent variable explicitly. This is fundamentally different from the implicit noise assumption in the previously suggested warped GP framework. We...
QoS-enhanced TNPOSS Network Model and its E2E Delay Bound for Multimedia Flows
Directory of Open Access Journals (Sweden)
Ke Xiong
2009-10-01
Full Text Available In our previous work, we proposed the TNPOSS (To Next-hop Port Sequence Switch network which can achieve scalable fast forwarding and is suitable for delivering multimedia flows. However, TNPOSS network has no Quality of Service (QoS tools to provide better QoS guarantee for multimedia flows which often have long-range dependence (LRD property. To enhance the QoS ability of TNPOSS network, this paper proposes a QoS-enhanced TNPOSS (QTNPOSS network model by introducing Fractal Leak Bucket (FLB shaper and Weighted Fair Queuing (WFQ scheduler into the original TNPOSS network. In the new QTNPOSS network, each packet of multimedia flows is shaped by the FLB when arriving at a node and is scheduled by the WFQ before being outputted. Based on study above, we further analyze the end-to-end (E2E delay bound of QTNPOSS network by means of the network calculus theory which is an effective mathematical tool on analyzing the worst-case QoS performances of networks. The service curve and the formulation of E2E delay bound of QTNPOSS network are presented and proved. Extensive numerical experiments show that both the LRD property of multimedia flows and the WFQ weight have influences on the E2E delay bound, and the WFQ weight influences the E2E delay bound more greatly than the LRD property does.
Charged Higgs Mass Bounds from $b \\to s \\gamma $in a Bilinear R-Parity Violating Model
Díaz, M A; Valle, José W F; Diaz, Marco A.
1999-01-01
The experimental measurement of the branching ratio $B(b\\to s\\gamma)$ imposes important constraints on the charged Higgs boson mass within the MSSM. We show that by adding bilinear R--Parity violation (BRpV) in the tau sector, these bounds are relaxed. In this model, a non--zero tau neutrino mass is induced. If squark masses are of a few TeV, the charged Higgs boson mass in the MSSM has to satisfy $m_{H^{\\pm}}\\gsim 570$ GeV. This bound on $m_{H^{\\pm}}$ is $\\sim 100$ GeV smaller in MSSM--BRpV. If squarks are lighter, then light charged Higgs bosons can be reconciled with $B(b\\to s\\gamma)$ only if there is also a light chargino. In the MSSM if we impose $m_{\\chi^{\\pm}_1}>90$ GeV then we need $m_{H^{\\pm}}\\gsim 110$ GeV. This bound on $m_{H^{\\pm}}$ is $\\sim 30$ GeV smaller in MSSM--BRpV. The relaxation of the bounds is due to the fact that charged Higgs bosons mix with staus and they contribute importantly to $B(b\\to contribution to $B(b\\to s\\gamma)$ can be safely neglected.
Bound states and the Bekenstein bound
Bousso, R
2004-01-01
We explore the validity of the generalized Bekenstein bound, S <= pi M a. We define the entropy S as the logarithm of the number of states which have energy eigenvalue below M and are localized to a flat space region of width a. If boundary conditions that localize field modes are imposed by fiat, then the bound encounters well-known difficulties with negative Casimir energy and large species number, as well as novel problems arising only in the generalized form. In realistic systems, however, finite-size effects contribute additional energy. We study two different models for estimating such contributions. Our analysis suggests that the bound is both valid and nontrivial if interactions are properly included, so that the entropy S counts the bound states of interacting fields.
Directory of Open Access Journals (Sweden)
Ballester Pla, Coralio
2012-03-01
Full Text Available The observation of the actual behavior by economic decision makers in the lab and in the field justifies that bounded rationality has been a generally accepted assumption in many socio-economic models. The goal of this paper is to illustrate the difficulties involved in providing a correct definition of what a rational (or irrational agent is. In this paper we describe two frameworks that employ different approaches for analyzing bounded rationality. The first is a spatial segregation set-up that encompasses two optimization methodologies: backward induction and forward induction. The main result is that, even under the same state of knowledge, rational and non-rational agents may match their actions. The second framework elaborates on the relationship between irrationality and informational restrictions. We use the beauty contest (Nagel, 1995 as a device to explain this relationship.
La observación del comportamiento de los agentes económicos tanto en el laboratorio como en la vida real justifica que la racionalidad acotada sea un supuesto aceptado en numerosos modelos socio-económicos. El objetivo de este artículo es ilustrar las dificultades que conlleva una correcta definición de qué es un agente racional (irracional. En este artículo se describen dos marcos que emplean diferentes metodologías para analizar la racionalidad acotada. El primero es un modelo de segregación espacial donde se contrastan dos metodologías de optimización: inducción hacia atrás y hacia adelante. El resultado principal es que, incluso con el mismo nivel de conocimiento, tanto agentes racionales como irracionales podrían coincidir en sus acciones. El segundo marco trabaja sobre la relación entre irracionalidad y restricción de información. Se utiliza el juego llamado “beauty contest” (Nagel 1995 como mecanismo para explicar dicha relación.
International Nuclear Information System (INIS)
A swing check valve which includes a valve body having an inlet and outlet is described. A recess in the valve body designed to hold a seal ring and a check valve disc swingable between open and closed positions. The disc is supported by a high strength wire secured at one end in a support spacer pinned through bearing blocks fixed to the valve body and at its other end in a groove formed on the outer peripheral surface of the disc. The parts are designed and chosen such to provide a lightweight valve disc which is held open by minimum velocity of fluid flowing through the valve which thus reduces oscillations and accompanying wear of bearings supporting the valve operating parts. (Auth.)
A Berry-Esseen bound for the uniform multinomial occupancy model
Bartroff, Jay
2012-01-01
The inductive size bias coupling technique and Stein's method yield a Berry-Esseen theorem for the number of urns having occupancy $d \\ge 2$ when $n$ balls are uniformly distributed over $m$ urns. In particular, there exists a constant $C$ depending only on $d$ such that $$ \\sup_{z \\in \\mathbb{R}}|P(W_{n,m} \\le z) -P(Z \\le z)| \\le C \\frac{\\sigma_{n,m}}{1+(\\frac{n}{m})^3} \\quad {for all $n \\ge d$ and $m \\ge 2$,} $$ where $W_{n,m}$ and $\\sigma_{n,m}^2$ are the standardized count and variance, respectively, of the number of urns with $d$ balls, and $Z$ is a standard normal random variable. Asymptotically, the bound is optimal up to constants if $n$ and $m$ tend to infinity together in a way such that $n/m$ stays bounded.
International Nuclear Information System (INIS)
Check valves are located in almost all safety and non-safety related fluid systems in a nuclear power plant. Malfunction or failure of these valves during plant operations, or in some cases under cold shutdown conditions, can seriously affect plant safety and result in costly, time-consuming maintenance. A major cause of check valve failure in the past has been excessive wear of internal components due to high disc flutter. Valve operation under conditions that cause the valve disc and hinge arm to oscillate or flutter can lead to degradations which, if undetected and not corrected, may result in malfunction or failure. Checkmate II, a portable, non-intrusive diagnostic system, has been developed to test various types of check valves using patented ultrasonic testing technology. The system comprises a computer, ultrasonic oscilloscope, transducers, and supporting hardware, and can identify many different phenomena, including: disc position and disc flutter; backstop and seat tapping; relative motion between hinge arm and disc; hinge pin wear and uneven hinge pin wear; disc stud wear and loosened stud nuts; combined stud and hinge pin wear, stuck and missing discs; broken springs. (author)
Ground-State Entanglement Bound for Quantum Energy Teleportation of General Spin-Chain Models
Hotta, Masahiro
2013-01-01
In protocols of quantum energy teleportation (QET), ground-state entanglement of many-body systems plays a crucial role. For a general class of spin-chain systems, we show analytically that the entanglement entropy is lower bounded by a positive quadratic function of the teleported energy between the regions of a QET protocol. This supports a general conjecture that ground-state entanglement is an evident physical resource for energy transportation in the context of QET
Czech Academy of Sciences Publication Activity Database
Aussel, D.; Červinka, Michal; Marechal, M.
2016-01-01
Roč. 50, č. 1 (2016), s. 19-38. ISSN 0399-0559 R&D Projects: GA ČR GAP402/12/1309; GA ČR GA201/09/1957 Institutional support: RVO:67985556 Keywords : Deregulated electricity market * production bounds * mathematical program with complementarity constraints * M-stationarity * calmness Subject RIV: BA - General Mathematics Impact factor: 0.405, year: 2014
Lower Bounds for Sorted Geometric Queries in the I/O Model
DEFF Research Database (Denmark)
Afshani, Peyman; Zeh, Norbert
2012-01-01
be optimal and in fact we can show that, for a particular class of “persistence-based” data structures, the space lower bound can be improved to Ω(N2 / MO(1)). Both these lower bounds are a first step towards understanding the complexity of sorted geometric query problems. All our lower bounds assume......We study sorted geometric query problems, a class of problems that, to the best of our knowledge and despite their applications, have not received much attention so far. Two of the most prominent problems in this class are angular sorting queries and sorted K-nearest neighbour queries. The former...... asks us to preprocess an input point set S in the plane so that, given a query point q, the clockwise ordering of the points in S around q can be computed efficiently. In the latter problem, the output is the list of K points in S closest to q, sorted by increasing distance from q. The goal in both...
Asokan, Shilpa M.; Destouni, Georgia
2014-05-01
The future of water resources in a region invariably depends on its historic as well as present water use management policy. In order to understand the past hydro-climatic conditions and changes, one needs to analyze observation data and their implications for climate and hydrology, such as Temperature, Precipitation, Runoff and Evapotranspiration in the region. In addition to the changes in climate, human re-distribution of water through land- and wateruse changes is found to significantly alter the water transfer from land to atmosphere through an increase or decrease in evapotranspiration. The Aral region in Central Asia, comprising the Aral Sea Drainage Basin and the Aral Sea, is an example case where the human induced changes in water-use have led to one of the worst environmental disasters of our time, the desiccation of the Aral Sea. Identification of the historical hydro-climatic changes that have happened in this region and their drivers is required before one can project future changes to water and its availability in the landscape. Knowledge of the future of water resources in the Aral region is needed for planning to meet increasing water and food demands of the growing population in conjunction with ecosystem sustainability. In order to project future scenarios of water on land, the Global Climate Model (GCM) ensemble of the Coupled Model Intercomparison Project, Phase 5 (CMIP5) was analyzed for their performance against hydrologically important, basin-scale observational climate and hydrological datasets. We found that the ensemble mean of 22 GCMs over-estimated the observed temperature by about 1°C for the historic period of 1961-1990. For the future extreme climate scenario RCP8.5 the increase in temperature was projected to be about 5°C by 2070-2099, the accuracy of which is questionable from identified biases of GCMs and their ensemble results compared with observations for the period 1961-1990. In particular, the water balance components
Model independent bounds on tensor modes and stringy parameters from CMB
Mazumdar, Anupam
2014-01-01
In this paper we will derive bounds on tensor-to-scalar ratio, $r$, string coupling, $g_s$ and compactification volume, ${\\cal V}_E$, by demanding the validity of an effective field theory - the inflationary scale and the Hubble parameter during inflation must be well below the Kaluza-Klein (KK) mass scale, string scale, and $4$ dimensional Planck mass. Within type IIB orientifold compactifications, we can put further constraints on the parameters by invoking the hierarchy between gravitino mass in $4$ dimensions and inflationary scale.
A Reduced Nonlinear Model of Wall-Bounded Shear Flow Turbulence
Farrell, Brian; Ioannou, Petros; Nikolaidis, Marios; Lozano-Duran, Adrian; Jimenez, Javier; Gayme, Dennice; Thomas, Vaughan
2015-11-01
The roll/streak is the dominant structure in the dynamics of wall-bounded shear flow turbulence. It appears that this structure arises from a nonlinear instability, the various proposed mechanisms for which are referred to as self-sustaining processes. However, even once the nonlinear instability is identified there remains the problem of understanding how this instability is regulated to maintain the observed turbulent state. Here both of these questions will be addressed by adopting the perspective of statistical state dynamics (SSD), specifically its reduced nonlinear (RNL) implementation. RNL comprises the joint evolution of the streamwise constant mean flow (first cumulant) and second order perturbation statistics (second cumulant). This restriction greatly reduces the complexity of the dynamics while retaining a realistic SSP. The perturbations supporting the SSP in RNL arise from parametric instability of the time-dependence streak the statistical stability of these perturbations being enforced by a feedback mediated control process operating between the mean flow and the perturbations. In this talk it will be shown how the maintenance and regulation of RNL turbulence allows insight into the mechanism of turbulence in wall-bounded shear flow.
Search for an upper bound of the renormalized Yukawa coupling in a lattice fermion-Higgs model
International Nuclear Information System (INIS)
We study the scaling laws for the fermion mass and the scalar field expectation value in the weak coupling region of the broken phase of a lattice regularized chiral-invariant SU(2)LxSU(2)R fermion-Higgs model with bare Yukawa coupling y and Wilson-Yukawa coupling w. In particular we concentrate on the region in the vicinity of the line A, which is the line of maximal values of y+4w on the critical surface containing the gaussian fixed point. We have not found any indication for the existence of a nontrivial fixed point on that line or anywhere else in the weak coupling region. The renormalized Yukawa coupling yR as a function of the fermionic correlation length appears to be bounded from above. The upper bound obtained from the numerical data at w=0 is compatible with the perturbation unitarity bound. Furthermore, in the weak coupling region, including the line A, it is not possible to choose w such that the unwanted fermion doublers would be removed from the physical particle spectrum. (orig.)
Call, Jared A.; Kwok, John H.; Fisher, Forest W.
2013-01-01
This innovation is a tool used to verify and validate spacecraft sequences at the predicted events file (PEF) level for the GRAIL (Gravity Recovery and Interior Laboratory, see http://www.nasa. gov/mission_pages/grail/main/index. html) mission as part of the Multi-Mission Planning and Sequencing Team (MPST) operations process to reduce the possibility for errors. This tool is used to catch any sequence related errors or issues immediately after the seqgen modeling to streamline downstream processes. This script verifies and validates the seqgen modeling for the GRAIL MPST process. A PEF is provided as input, and dozens of checks are performed on it to verify and validate the command products including command content, command ordering, flight-rule violations, modeling boundary consistency, resource limits, and ground commanding consistency. By performing as many checks as early in the process as possible, grl_pef_check streamlines the MPST task of generating GRAIL command and modeled products on an aggressive schedule. By enumerating each check being performed, and clearly stating the criteria and assumptions made at each step, grl_pef_check can be used as a manual checklist as well as an automated tool. This helper script was written with a focus on enabling the user with the information they need in order to evaluate a sequence quickly and efficiently, while still keeping them informed and active in the overall sequencing process. grl_pef_check verifies and validates the modeling and sequence content prior to investing any more effort into the build. There are dozens of various items in the modeling run that need to be checked, which is a time-consuming and errorprone task. Currently, no software exists that provides this functionality. Compared to a manual process, this script reduces human error and saves considerable man-hours by automating and streamlining the mission planning and sequencing task for the GRAIL mission.
Non intrusive check valve diagnostics at Bruce A
International Nuclear Information System (INIS)
Bruce A purchased non intrusive check valve diagnostic equipment in 1995 to ensure operability and availability of critical check valves in the Station. Diagnostics can be used to locate and monitor check valve degradation modes. Bruce A initiated a pilot program targeting check valves with flow through them and ones that completed open or close cycles. Approaches to determine how to confirm operability of passive check valves using non intrusive techniques were explored. A sample population of seventy-three check valves was selected to run the pilot program on prior to complete implementation. The pilot program produced some significant results and some inconclusive results. The program revealed a major finding that check valve performance modeling is required to ensure continuous operability of check valves. (author)
Non intrusive check valve diagnostics at Bruce A
Energy Technology Data Exchange (ETDEWEB)
Marsch, S.P. [Ontario Hydro, Bruce Nuclear Generating Station A, Tiverton, ON (Canada)
1997-07-01
Bruce A purchased non intrusive check valve diagnostic equipment in 1995 to ensure operability and availability of critical check valves in the Station. Diagnostics can be used to locate and monitor check valve degradation modes. Bruce A initiated a pilot program targeting check valves with flow through them and ones that completed open or close cycles. Approaches to determine how to confirm operability of passive check valves using non intrusive techniques were explored. A sample population of seventy-three check valves was selected to run the pilot program on prior to complete implementation. The pilot program produced some significant results and some inconclusive results. The program revealed a major finding that check valve performance modeling is required to ensure continuous operability of check valves. (author)
Online treatment compliance checking for clinical pathways.
Huang, Zhengxing; Bao, Yurong; Dong, Wei; Lu, Xudong; Duan, Huilong
2014-10-01
Compliance checking for clinical pathways (CPs) is getting increasing attention in health-care organizations due to stricter requirements for cost control and treatment excellence. Many compliance measures have been proposed for treatment behavior inspection in CPs. However, most of them look at aggregated data seen from an external perspective, e.g. length of stay, cost, infection rate, etc., which may provide only a posterior impression of the overall conformance with the established CPs such that in-depth and in near real time checking on the compliance of the essential/critical treatment behaviors of CPs is limited. To provide clinicians real time insights into violations of the established CP specification and support online compliance checking, this article presents a semantic rule-based CP compliance checking system. In detail, we construct a CP ontology (CPO) model to provide a formal grounding of CP compliance checking. Using the proposed CPO, domain treatment constraints are modeled into Semantic Web Rule Language (SWRL) rules to specify the underlying treatment behaviors and their quantified temporal structure in a CP. The established SWRL rules are integrated with the CP workflow such that a series of applicable compliance checking and evaluation can be reminded and recommended during the pathway execution. The proposed approach can, therefore, provides a comprehensive compliance checking service as a paralleling activity to the patient treatment journey of a CP rather than an afterthought. The proposed approach is illustrated with a case study on the unstable angina clinical pathway implemented in the Cardiology Department of a Chinese hospital. The results demonstrate that the approach, as a feasible solution to provide near real time conformance checking of CPs, not only enables clinicians to uncover non-compliant treatment behaviors, but also empowers clinicians with the capability to make informed decisions when dealing with treatment compliance
Model Study of Three-Body Forces in the Three-Body Bound State
Liu, H; Glöckle, W; Elster, Ch.
2003-01-01
The Faddeev equations for the three-body bound state with two- and three-body forces are solved directly as three-dimensional integral equation. The numerical feasibility and stability of the algorithm, which does not employ partial wave decomposition is demonstrated. The three-body binding energy and the full wave function are calculated with Malfliet-Tjon-type two-body potentials and scalar Fujita-Miyazawa type three-body forces. The influence of the strength and range of the three-body force on the wave function, single particle momentum distributions and the two-body correlation functions are studied in detail. The extreme case of pure three-body forces is investigated as well.
Research on Model Checking Formal Language Object-Z%形式语言Object-Z的模型检测研究
Institute of Scientific and Technical Information of China (English)
吴彩燕
2015-01-01
Object-Z是一种用于表示面向对象系统规约的高层抽象语言，由于缺乏自动验证工具的支持，很难建立直接证明由Object-Z表示的面向对象系统规约正确性，成为Object-Z被广泛采用的最大障碍。模型检测是一种验证系统规约正确性的自动化技术。使用模型检测工具SPIN验证Object-Z描述的正确性，把Object-Z的规约转换成标记转换系统，然后把标记转换系统转换为SPIN的输入语言Promela，使用线性时序逻辑刻画Object-Z中的历史不变式。通过对订票系统类的Object-Z描述的验证，结果表明该方案具有可行性。%Object-Z is a high-level abstract language used to represent the specification of the object-oriented system.For lack of support of automatic verification tools,it is difficult to verify the correctness of the specification of the object-oriented system represented by Object-Z.Model checking is such an automatic verification technique.This paper verifies the correctness of the Object-Z specification using model checking tool-SPIN,which translates the Object-Z specification into label transition system (LTS)firstly,and then converts the LTS format into the input language Promelaof SPIN.Subsequently,the history invariant in Object-Z is described by Linear Temporal Logic (LTL).Through verifying the Object-Z specification of the booking system class,the results show that this method is feasible.
Model Checking Multivariate State Rewards
DEFF Research Database (Denmark)
Nielsen, Bo Friis; Nielson, Flemming; Nielson, Hanne Riis
2010-01-01
We consider continuous stochastic logics with state rewards that are interpreted over continuous time Markov chains. We show how results from multivariate phase type distributions can be used to obtain higher-order moments for multivariate state rewards (including covariance). We also generalise...
2010-01-01
... checking: Check pilots (aircraft), check pilots (simulator). 91.1093 Section 91.1093 Aeronautics and Space....1093 Initial and transition training and checking: Check pilots (aircraft), check pilots (simulator... observation check may be accomplished in part or in full in an aircraft, in a flight simulator, or in a...
Takahashi, Takéo
2003-01-01
In this paper, we study a fluid--rigid-body interaction problem. The motion of the fluid is modeled by the Navier-Stokes equations, written in an unknown bounded domain depending on the displacement of the rigid body. Our main result yields existence and uniqueness of strong solutions. In the two-dimensional case, the solutions are global provided that the rigid body does not touch the boundary. In the three-dimensional case, we obtain local-in-time existence and global existen...
Model-independent analysis of B → π K decays and bounds on the weak phase γ
International Nuclear Information System (INIS)
A general parametrization of the amplitudes for the rare two-body decays B → π K is introduced, which makes maximal use of theoretical constraints arising from flavour symmetries of the strong interactions and the structure of the low-energy effective weak Hamiltonian. With the help of this parametrization, a model-independent analysis of the branching ratios and direct CP asymmetries in the various B → π K decay modes is performed, and the impact of hadronic uncertainties on bounds on the weak phase γ = arg(Vub*) is investigated. (author)
Feasibility Checking for Dial-a-Ride Problems
DEFF Research Database (Denmark)
Haugland, Dag; Ho, Sin C.
Hunsaker and Savelsbergh have proposed an algorithm for testing feasibility of a route in the solution to the dial-a-ride problem. The constraints that are checked are load capacity constraints, time windows, ride time bounds and wait time bounds. The algorithm has linear running time. By virtue ...... a simple example, we show in this work that their algorithm is incorrect. We also prove that by increasing the time complexity by only a logarithmic factor, a correct algorithm is obtained....
International Nuclear Information System (INIS)
In this work some families of relativistic anisotropic charged fluid spheres have been obtained by solving the Einstein-Maxwell field equations with a preferred form of one of the metric potentials, and suitable forms of electric charge distribution and pressure anisotropy functions. The resulting equation of state (EOS) of the matter distribution has been obtained. Physical analysis shows that the relativistic stellar structure for the matter distribution considered in this work may reasonably model an electrically charged compact star whose energy density associated with the electric fields is on the same order of magnitude as the energy density of fluid matter itself (e.g., electrically charged bare strange stars). Furthermore these models permit a simple method of systematically fixing bounds on the maximum possible mass of cold compact electrically charged self-bound stars. It has been demonstrated, numerically, that the maximum compactness and mass increase in the presence of an electric field and anisotropic pressures. Based on the analytic models developed in this present work, the values of some relevant physical quantities have been calculated by assuming the estimated masses and radii of some well-known potential strange star candidates like PSR J1614-2230, PSR J1903+327, Vela X-1, and 4U 1820-30. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Murad, Mohammad Hassan [BRAC University, Department of Mathematics and Natural Sciences, Dhaka (Bangladesh); Fatema, Saba [Daffodil International University, Department of Natural Sciences, Dhaka (Bangladesh)
2015-11-15
In this work some families of relativistic anisotropic charged fluid spheres have been obtained by solving the Einstein-Maxwell field equations with a preferred form of one of the metric potentials, and suitable forms of electric charge distribution and pressure anisotropy functions. The resulting equation of state (EOS) of the matter distribution has been obtained. Physical analysis shows that the relativistic stellar structure for the matter distribution considered in this work may reasonably model an electrically charged compact star whose energy density associated with the electric fields is on the same order of magnitude as the energy density of fluid matter itself (e.g., electrically charged bare strange stars). Furthermore these models permit a simple method of systematically fixing bounds on the maximum possible mass of cold compact electrically charged self-bound stars. It has been demonstrated, numerically, that the maximum compactness and mass increase in the presence of an electric field and anisotropic pressures. Based on the analytic models developed in this present work, the values of some relevant physical quantities have been calculated by assuming the estimated masses and radii of some well-known potential strange star candidates like PSR J1614-2230, PSR J1903+327, Vela X-1, and 4U 1820-30. (orig.)
Quark model calculation of $\\eta \\to l^+ l^-$ to all orders in the bound state relative momentum
Margolis, B; Phipps, M; Trottier, H D
1993-01-01
The electromagnetic box diagram for the leptonic decays of pseudoscalar mesons in the quark model is evaluated to all orders in ${\\bf p} / m_q$, where ${\\bf p}$ is the relative three-momentum of the quark-antiquark pair and $m_q$ is the quark mass. We compute $B_P \\equiv \\Gamma(\\eta \\to l^+ l^-) / \\Gamma(\\eta \\to \\gamma\\gamma)$ using a popular nonrelativistic (NR) harmonic oscillator wave function, and with a relativistic momentum space wave function that we derive from the MIT bag model. We also compare with a calculation in the limit of extreme NR binding due to Bergstr\\"om. Numerical calculations of $B_P$ using these three parameterizations of the wave function agree to within a few percent over a wide kinematical range. We find that the quark model leads in a natural way to a negligible value for the ratio of dispersive to absorptive parts of the electromagnetic amplitude for $\\eta \\to \\mu^+ \\mu^-$ (unitary bound). However we find substantial deviations from the unitary bound in other kinematical regions,...
Bonura Carlo A; Boersma Jonathan T; Tse Wai S; Eckert Michael J; Szechtman Henry; McClelland Jessica Z; Culver Kirsten E; Eilam David
2001-01-01
Abstract Background A previous report showed that the open field behavior of rats sensitized to the dopamine agonist quinpirole satisfies 5 performance criteria for compulsive checking behavior. In an effort to extend the parallel between the drug-induced phenomenon and human obsessive-compulsive disorder (OCD), the present study investigated whether the checking behavior of quinpirole rats is subject to interruption, which is an attribute characteristic of OCD compulsions. For this purpose, ...
Bounding the ντ magnetic moment the process e+e- → ν ν-bar γ in a left-right symmetric model
International Nuclear Information System (INIS)
A bound on the ντ magnetic moment is calculated through the reaction e+e- → ν ν-bar γ at the Z1-pole, and in the framework of a left-right symmetric model at LEP energies. We find that the bound is almost independent of the mixing angle φ of the model in the allowed experimental range for this parameter (Authors)
Quark model calculation of η→l+l- to all orders in the bound-state relative momentum
International Nuclear Information System (INIS)
We analyze the electromagnetic amplitude for the leptonic decays of pseudoscalar mesons in the quark model, with particular emphasis on η→l+l- (l=e,μ). We evaluate the electromagnetic box diagram for a quark-antiquark pair with an arbitrary distribution of relative three-momentum p: the amplitude is obtained to all orders in p/mq, where mq is the quark mass. We compute BP≡Γ(η→l+l-)/Γ(η→γγ) using a harmonic oscillator wave function that is widely used in nonrelativistic (NR) quark model calculations, and with a relativistic momentum space wave function that we derive from the MIT bag model. We also compare with a quark model calculation in the limit of extreme NR binding due to Bergstroem. Numerical calculations of BP using these three parametrizations of the wave function agree to within a few percent over a wide kinematical range. Our results show that the quark model leads in a natural way to a negligible value for the ratio of dispersive to absorptive parts of the electromagnetic amplitude for η→μ+μ- (unitary bound). However we find substantial deviations from the unitary bound in other kinematical regions, such as η,π0→e+e-. Using the experimental branching ratio for η→γγ as input, these quark models yield B(η→μ+μ-)∼4.3x10-6, within errors of the recent SATURNE measurement of 5.1±0.8x10-6, and B(η→e+e-)∼6.3x10-9
Ground-state-entanglement bound for quantum energy teleportation of general spin-chain models
Hotta, Masahiro
2013-03-01
Many-body quantum systems in the ground states have zero-point energy due to the uncertainty relation. In many cases, the system in the ground state accompanies spatially entangled energy density fluctuation via the noncommutativity of the energy density operators, though the total energy takes a fixed value, i.e., the lowest eigenvalue of the Hamiltonian. Quantum energy teleportation (QET) is a protocol for the extraction of the zero-point energy out of one subsystem using information of a remote measurement of another subsystem. From an operational viewpoint of protocol users, QET can be regarded as an effective rapid energy transportation without breaking all physical laws, including causality and local energy conservation. In the protocol, the ground-state entanglement plays a crucial role. In this paper, we show analytically for a general class of spin-chain systems that the entanglement entropy is lower bounded by a positive quadratic function of the teleported energy between the regions of a QET protocol. This supports a general conjecture that ground-state entanglement is an evident physical resource for energy transportation in the context of QET. The result may also deepen our understanding of the energy density fluctuation in condensed-matter systems from a perspective of quantum information theory.
NLO+NLL Collider Bounds, Dirac Fermion and Scalar Dark Matter in the B-L Model
Klasen, Michael; Queiroz, Farinaldo S
2016-01-01
Baryon and lepton numbers being accidental global symmetries of the Standard Model (SM), it is natural to promote them to local symmetries. However, to preserve anomaly freedom, only combinations of B-L are viable. In this spirit, we investigate possible dark matter realizations in the context of the $U(1)_{B-L}$ model: (i) Dirac fermion with unbroken B-L; (ii) Dirac fermion with broken B-L; (iii) scalar dark matter; (iv) two component dark matter. We compute the relic abundance, direct and indirect detection observables and confront them with recent results from Planck, LUX-2016, and Fermi-LAT and prospects from XENON1T. In addition to the well known LEP bound $M_{Z^{\\prime}}/g_{BL} \\gtrsim 7$ TeV, we include often ignored LHC bounds using 13 TeV dilepton (dimuon+dielectron) data at next-to-leading order plus next-to-leading logarithmic accuracy. We show that, for gauge couplings smaller than $0.4$, the LHC gives rise to the strongest collider limit. In particular, we find $M_{Z^{\\prime}}/g_{BL} > 8.7$ TeV f...
International Nuclear Information System (INIS)
Highlights: • A grid-spacing free, instability-sensitive Reynolds stress model is formulated. • The model is capable of capturing turbulence fluctuations. • Substantial improvement concerning proper turbulence activity enhancement is achieved. • The model is intensively validated in a series of 2D and 3D separating flows. • The model feasibility is also checked in some attached flows. - Abstract: The incapability of the conventional Unsteady RANS (Reynolds–Averaged Navier Stokes) models to adequately capture turbulence unsteadiness presents the prime motivation of the present work, which focuses on formulating an instability-sensitive, eddy-resolving turbulence model on the Second-Moment Closure level. The model scheme adopted, functioning as a ‘sub-scale’ model in the Unsteady RANS framework, represents a differential near-wall Reynolds stress model formulated in conjunction with the scale-supplying equation governing the homogeneous part of the inverse turbulent time scale ωh (ωh = εh/k). The latter equation was straightforwardly obtained from the model equation describing the dynamics of the homogeneous part of the total viscous dissipation rate ε, defined as εh = ε − 0.5ν∂2k/(∂xj∂xj) (Jakirlic and Hanjalic, 2002), by applying the derivation rules to the expression for ωh. The model capability to account for vortex length and time scales variability was enabled through an additional term in the corresponding length-scale determining equation, providing a selective enhancement of its production, pertinent particularly to the highly unsteady separated shear layer region, modeled in terms of the von Karman length scale (comprising the second derivative of the velocity field) in line with the SAS (Scale-Adaptive Simulation) proposal (Menter and Egorov, 2010). The present model formulation, termed as SRANS model (Sensitized RANS), does not comprise any parameter depending explicitly on grid spacing. The predictive capabilities of the
A standard-model self-consistent multibody bound-state Higgs scalar near the tt-bar threshold
International Nuclear Information System (INIS)
We consider a simple model in which a non-elementary electroweak neutral Higgs scalar (H) can arise primarily as a multibody bound state which can include large numbers of constituent particles. Only standard-model elementary particles and effects with an energy scale ∼1 TeV have to be introduced explicitly. We do this by working with a non-perturbative analytic tt-bar scattering-amplitude unitarization scheme (basically a relativistic generalization of the usual Schroedinger equation), but with a strong high-energy (multibody) inelastic contribution added in, and with no divergences requiring arbitrary cut-offs or subtraction constants. The H itself is required to be simultaneously consistent in both mass and coupling with the exchange of the same H in the crossed channel when constructing the relativistic generalization of the input potential. The strong energy dependence of our amplitude near the tt-bar threshold then leads to a bound-state H with standard-model coupling and mass calculated to be near that tt-bar threshold, a result which is expected to persist for a broad class of similar models and suggests that alternative solutions may be obtained with H immediately below the ZZ or W+W- thresholds. We also find that our high-energy tt-bar scattering-amplitude multibody inelastic contribution can be constructed explicitly from the exchange of a Regge trajectory passing through the H and generated dynamically in the same way (but for unphysical angular momentum). Finally, we find that we can have massive W± and Z with longitudinal polarizations and approximately correct masses and standard-model couplings. These may be accompanied by higher-mass states with the same quantum numbers. (author)
Formal verification of SDG diagnosability via symbolic model checking%基于符号模型检测的SDG模型可诊断性验证
Institute of Scientific and Technical Information of China (English)
宁宁; 张骏; 高向阳; 薛静
2011-01-01
由于定量信息和非线性因果关系的丢失,符号有向图(signed directed graph,SDG)模型的可诊断性需要进一步地进行校核与验证.为此,提出了基于符号模型检测的SDG模型可诊断性形式化验证方法.首先定义了SDG模型的有限状态变迁系统形式化描述,建立了符号模型验证器(symbolic model verifier,SMV)模型;其次利用SDG的深层知识,构造了可诊断性函数,设定了可诊断性上下文,给出了可诊断性定义.然后,构造了SDG耦合孪生SMV模型,定义了可诊断性的计算树时态逻辑公式,提出了验证算法SDGD-CSMV.最后,通过一个实例验证了可诊断性的判定和算法的有效性.%Because of quantitative and nonlinear causal information, diagosability of the signed directed graph(SDG) model needs to be further verified and validated. A formal verification approach to diagnosability via symbolic model checking is proposed. A formal characterization of SDG, as a finite state transition system,is transformed firstly, and a symbolic model verifier (SMV) module is modeled. In the framework of the finite state transition system, a diagnosis function is established, and then the diagnosable definition of a diagnosis condition is defined using the idea of diagnosis context. By means of NuSMV, a coupled SMV module is constructed, and then the SDGD_CSMV algorithm is designed with the computation temporal logic (CTL) definition of diagnosable property. Finally, the practical applicability within a simple water tank SDG model is demonstrated, which proves the validation of the diagnosable definition and SDGD_CSMV.
Bersani, Marcello M; Frigeri, Achille; Pradella, Matteo; Rossi, Matteo
2010-01-01
An important problem that arises during the execution of service-based applications concerns the ability to determine whether a running service can be substituted with one with a different interface, for example if the former is no longer available. Standard Bounded Model Checking techniques can be used to perform this check, but they must be able to provide answers very quickly, lest the check hampers the operativeness of the application, instead of aiding it. The problem becomes even more complex when conversational services are considered, i.e., services that expose operations that have Input/Output data dependencies among them. In this paper we introduce a formal verification technique for an extension of Linear Temporal Logic that allows users to include in formulae constraints on integer variables. This technique applied to the substitutability problem for conversational services is shown to be considerably faster and with smaller memory footprint than existing ones.
Bounds on the slope and curvature of Isgur-Wise function in a QCD-inspired quark model
Energy Technology Data Exchange (ETDEWEB)
Hazarika, Bhaskar Jyoti [Department of Physics, Pandu College, Guwahati (India); Choudhury, D.K. [Department of Physics, Gauhati University, Guwahati (India)
2011-09-15
The quantum chromodynamics-inspired potential model pursued by us earlier has been recently modified to incorporate an additional factor 'c' in the linear cum Coulomb potential. While it felicitates the inclusion of standard confinement parameter b = 0.183 GeV{sup 2} unlike in previous work, it still falls short of explaining the Isgur-Wise function for the B mesons without ad hoc adjustment of the strong coupling constant. In this work, we determine the factor 'c' from the experimental values of decay constants and masses and show that the reality constraint on 'c' yields bounds on the strong coupling constant as well as on slope and curvature of Isgur-Wise function allowing more flexibility to the model. (author)
DEFF Research Database (Denmark)
Baadsgaard, Mikkel; Nielsen, Jan Nygaard; Madsen, Henrik
2000-01-01
An econometric analysis of continuous-timemodels of the term structure of interest rates is presented. A panel of coupon bond prices with different maturities is used to estimate the embedded parameters of a continuous-discrete state space model of unobserved state variables: the spot interest rate...... stochastic noise term should account for model errors. A nonlinear filtering method is used to compute estimates of the state variables, and the model parameters are estimated by a quasimaximum likelihood method provided that some assumptions are imposed on the model residuals. Both Monte Carlo simulation...
Connolly, Joseph W.; Kopasakis, George
2010-01-01
This paper covers the propulsion system component modeling and controls development of an integrated mixed compression inlet and turbojet engine that will be used for an overall vehicle Aero-Propulso-Servo-Elastic (APSE) model. Using previously created nonlinear component-level propulsion system models, a linear integrated propulsion system model and loop shaping control design have been developed. The design includes both inlet normal shock position control and jet engine rotor speed control for a potential supersonic commercial transport. A preliminary investigation of the impacts of the aero-elastic effects on the incoming flow field to the propulsion system are discussed, however, the focus here is on developing a methodology for the propulsion controls design that prevents unstart in the inlet and minimizes the thrust oscillation experienced by the vehicle. Quantitative Feedback Theory (QFT) specifications and bounds, and aspects of classical loop shaping are used in the control design process. Model uncertainty is incorporated in the design to address possible error in the system identification mapping of the nonlinear component models into the integrated linear model.
Institute of Scientific and Technical Information of China (English)
丁国兴; 王宏彦; 邱建斌; 高伟
2014-01-01
According to non-standardized modeling in the system integration of smart substation, a standardized model checking software which checks model files of relay devices is developed to improve the efficiency of system integration. The checking is firstly based on IEC 61850 SCL schema to determine if there are mistakes to lead to analysis fault. A rules bank is built based on relay applying model published by SGCC. The checking also compares the model and rules bank to determine if the definition of logic objects follows the standard of SGCC, such as naming regular, mandatory existing, etc. The checking software is developed using Java/Netbeans and can be compatible to Win32 or Linux platform. The checking software runs quickly and accurately which nicely meets the needs of system integration. An application example is introduced finally, which proves the design of the model checking software is effective.%针对智能变电站系统集成中保护装置建模不规范的情况，开发一种保护模型规范化测试软件对装置模型进行规范化检测，以提高智能变电站系统集成效率。软件基于IEC 61850 SCL schema对模型进行语法检查，以确定其中是否存在导致解析错误的定义；并根据国网公司《IEC 61850工程继电保护应用模型》创建规则库，比对检查模型中各种逻辑对象的建模，如命名要求、强制包含性要求等，以确定模型是否遵循国网公司标准。软件采用Java/Netbeans工具开发，兼容Win32/Linux平台，检测准确迅速，满足智能变电站系统集成中模型检测的需要。最后提供了对实际保护模型文件进行检测的实例。
Butera, P; Pernici, M
2015-01-01
Using a relation between the virial expansion coefficients of the pressure and the entropy expansion coefficients in the case of the monomer-dimer model on infinite regular lattices, we have shown that, on hypercubic lattices of any dimension, the virial coefficients are positive through the 20th order. We have observed that all virial coefficients so far known for this system are positive also on infinite regular lattices with different structure. We are thus led to conjecture that the virial expansion coefficients $m_k $ are always positive. These considerations can be extended to the study of related bounds on finite graphs generalizing the infinite regular lattices, namely the finite grids and the regular biconnected graphs. The validity of the bounds $\\Delta^k {\\rm ln}(i! N(i)) \\le 0$ for $k \\ge 2$, where $N(i)$ is the number of configurations of $i$ dimers on the graph and $\\Delta$ is the forward difference operator, is shown to correspond to the positivity of the virial coefficients. Our tests on many ...
2010-01-01
... checking: Check airmen (aircraft), check airmen (simulator). 135.339 Section 135.339 Aeronautics and Space... and checking: Check airmen (aircraft), check airmen (simulator). (a) No certificate holder may use a... an aircraft, in a flight simulator, or in a flight training device. This paragraph applies...
Phase separation in random cluster models I: uniform upper bounds on local deviation
Hammond, Alan
2010-01-01
This is the first in a series of three papers that addresses the behaviour of the droplet that results, in the percolating phase, from conditioning the Fortuin-Kasteleyn planar random cluster model on the presence of an open dual circuit Gamma_0 encircling the origin and enclosing an area of at least (or exactly) n^2. (By the Fortuin-Kasteleyn representation, the model is a close relative of the droplet formed by conditioning the Potts model on an excess of spins of a given type.) We consider...
Pusey, Jason L.; Yoo, Jin-Hyeong
2014-06-01
We document the design and preliminary numerical simulation study of a high fidelity model of Canid, a recently introduced bounding robot. Canid is a free-standing, power-autonomous quadrupedal machine constructed from standard commercially available electromechanical and structural elements, incorporating compliant C-shaped legs like those of the decade old RHex design, but departing from that standard (and, to the best of our knowledge, from any prior) robot platform in its parallel actuated elastic spine. We have used a commercial modeling package to develop a finite-element model of the actuated, cable-driven, rigid-plate-reinforced harness for the carbon-fiber spring that joins the robot's fore- and hind-quarters. We compare a numerical model of this parallel actuated elastic spine with empirical data from preliminary physical experiments with the most important component of the spine assembly: the composite leaf spring. Specifically, we report our progress in tuning the mechanical properties of a standard modal approximation to a conventional compliant beam model whose boundary conditions represent constraints imposed by the actuated cable driven vertebral plates that comprise the active control affordance over the spine. We conclude with a brief look ahead at near-term future experiments that will compare predictions of this fitted composite spring model with data taken from the physical spine flexed in isolation from the actuated harness.
Bounded Rational Managers Struggle with Talent Management - An Agent-based Modelling Approach
DEFF Research Database (Denmark)
Adamsen, Billy; Thomsen, Svend Erik
This study applies an agent-based modeling approach to explore some aspects of an important managerial task: finding and cultivating talented individuals capable of creating value for their organization at some future state. Given that the term talent in talent management is an empty signifier...... of past success will provide failure rather than success in the future (Capelli.2008). Finally, we model the talent selection process either as a collective decision making process made by a group of managers or a decision process made by a single manager.It is argued that agent-based modeling is a useful...... method for studying this type of problems. The approach is particularly suitable to topics where understanding processes and their consequences is important. Agent-based models can include agents that are heterogeneous in their features and abilities, and can deal directly with the consequences...
An extension of the cosmological standard model with a bounded Hubble expansion rate
Cortés, J. L.; Induráin, J.
2009-01-01
Abstract The possibility of having an extension of the cosmological standard model with a Hubble expansion rate H constrained to a finite interval is considered. Two periods of accelerated expansion arise naturally when the Hubble expansion rate approaches to the two limiting values. The new description of the history of the universe is confronted with cosmological data and with several theoretical ideas going beyond the standard cosmological model.
Bounds on Higgs-Portal models from the LHC Higgs data
Cheung, Kingman; Lee, Jae Sik; Tseng, Po-Yan
2015-01-01
In a number of Higgs-portal models, an $SU(2)$ isospin-singlet scalar boson generically appears at the electroweak scale and can mix with the Standard Model (SM) Higgs boson with a mixing angle $\\alpha$. This singlet scalar boson can have renormalizable couplings to a pair of dark matter particles, vectorlike leptons or quarks, or new gauge bosons, thereby modifying the Higgs signal strengths in a nontrivial way. In this work, we perform global fits to such models using the most updated LHC Higgs-boson data and discuss the corresponding implications on Higgs-portal-type models. In particular we find that the current LHC Higgs-boson data slightly favors the SM over the Higgs-portal singlet-scalar models, which has to be further examined using the upcoming LHC Higgs-boson data. Finally the Higgs-portal models are constrained as follows: $\\cos\\alpha \\gtrsim 0.86$ and $\\Delta \\Gamma_{\\rm tot} \\lesssim 1.9$ MeV at 95 \\% CL.
Social Rationality as a Unified Model of Man (Including Bounded Rationality)
Lindenberg, Siegwart
2001-01-01
In 1957, Simon published a collection of his essays under the title of “Models of Man: Social and Rational”. In the preface, he explains the choice for this title: All of the essays “are concerned with laying foundations for a science of man that will comfortably accommodate his dual nature as a social and as a rational animal.” (p. vii) Observe that the title of the book refers to two models of man, one social and one rational. Throughout his life, Simon kept contributing to this science of ...
Energy Technology Data Exchange (ETDEWEB)
Nasser, I [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Abdelmonem, M S [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Bahlouli, H [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Alhaidari, A D [Shura Council, Riyadh 11212 (Saudi Arabia)
2007-11-14
This is the first in a series of articles in which we study the rotating Morse potential model for diatomic molecules in the tridiagonal J-matrix representation. Here, we compute the bound-state energy spectrum by diagonalizing the finite-dimensional Hamiltonian matrix of H{sub 2}, LiH, HCl and CO molecules for arbitrary angular momentum. The calculation was performed using the J-matrix basis that supports a tridiagonal matrix representation for the reference Hamiltonian. Our results for these diatomic molecules have been compared with available numerical data satisfactorily. The proposed method is handy, very efficient, and it enhances accuracy by combining analytic power with a convergent and stable numerical technique.
Hadizadeh, M R; Bayegan, S
2011-01-01
A recently developed three-dimensional approach (without partial-wave decomposition) is considered to investigate solutions of Faddeev-Yakubovsky integral equations in momentum space for three- and four-body bound states, with the inclusion of three-body forces. In the calculations of the binding energies, spin-dependent nucleon-nucleon (NN) potential models (named, S$_{3}$, MT-I/III, YS-type and P$_{5.5}$GL) are considered along with the scalar two-meson exchange three-body potential. Good agreement of the presently reported results with the ones obtained by other techniques are obtained, demonstrating the advantage of an approach in which the formalism is much more simplified and easy to manage for direct computation.
High-order lattice Boltzmann models for wall-bounded flows at finite Knudsen numbers
Feuchter, C
2015-01-01
We analyze a large number of high-order discrete velocity models for solving the Boltzmann-BGK equation for finite Knudsen number flows. Using the Chapman-Enskog formalism, we prove for isothermal flows a relation identifying the resolved flow regimes for low Mach numbers. Although high-order lattice Boltzmann models recover flow regimes beyond the Navier-Stokes level we observe for several models significant deviations from reference results. We found this to be caused by their inability to recover the Maxwell boundary condition exactly. By using supplementary conditions for the gas-surface interaction it is shown how to systematically generate discrete velocity models of any order with the inherent ability to fulfill the diffuse Maxwell boundary condition accurately. Both high-order quadratures and an exact representation of the boundary condition turn out to be crucial for achieving reliable results. For Poiseuille flow, we can reproduce the mass flow and slip velocity up to the Knudsen number of 1. Moreov...
Social Rationality as a Unified Model of Man (Including Bounded Rationality)
Lindenberg, Siegwart
2001-01-01
In 1957, Simon published a collection of his essays under the title of “Models of Man: Social and Rational”. In the preface, he explains the choice for this title: All of the essays “are concerned with laying foundations for a science of man that will comfortably accommodate his dual nature as a soc
Numerical Model of Turbulence, Sediment Transport, and Sediment Cover in a Large Canyon-Bound River
Alvarez, L. V.; Schmeeckle, M. W.
2013-12-01
The Colorado River in Grand Canyon is confined by bedrock and coarse-grained sediments. Finer grain sizes are supply limited, and sandbars primarily occur in lateral separation eddies downstream of coarse-grained tributary debris fans. These sandbars are important resources for native fish, recreational boaters, and as a source of aeolian transport preventing the erosion of archaeological resources by gully extension. Relatively accurate prediction of deposition and, especially, erosion of these sandbar beaches has proven difficult using two- and three-dimensional, time-averaged morphodynamic models. We present a parallelized, three-dimensional, turbulence-resolving model using the Detached-Eddy Simulation (DES) technique. DES is a hybrid large eddy simulation (LES) and Reynolds-averaged Navier Stokes (RANS). RANS is applied to the near-bed grid cells, where grid resolution is not sufficient to fully resolve wall turbulence. LES is applied further from the bed and banks. We utilize the Spalart-Allmaras one equation turbulence closure with a rough wall extension. The model resolves large-scale turbulence using DES and simultaneously integrates the suspended sediment advection-diffusion equation. The Smith and McLean suspended sediment boundary condition is used to calculate the upward and downward settling of sediment fluxes in the grid cells attached to the bed. The model calculates the entrainment of five grain sizes at every time step using a mixing layer model. Where the mixing layer depth becomes zero, the net entrainment is zero or negative. As such, the model is able to predict the exposure and burial of bedrock and coarse-grained surfaces by fine-grained sediments. A separate program was written to automatically construct the computational domain between the water surface and a triangulated surface of a digital elevation model of the given river reach. Model results compare favorably with ADCP measurements of flow taken on the Colorado River in Grand Canyon
Interference checking approach with tolerance based on assembly dimension chain
Institute of Scientific and Technical Information of China (English)
Wang Lei; Li Yingguang; Wang Wei; and Liao Wenhe
2012-01-01
CAD model with nominal dimension is implemented in interference checking of assembly simulation of aircraft complex parts at present, which causes inadequate availability. In order to address this challenging issue, interference checking method with tolerance based on assembly dimension chain was proposed. Worst case and maximum error probability of tolerance of composing loop were used, and CAD models were respectively re-constructed and inserted into simulation system. Before dynamic interference checking, engineering semantic interference condition was set to assembly requirements. Finally, the interface checking result was a basis for reasonability of assembly process and tolerance. A prototype system was developed based on the above research.
Nearly Optimal Bounds for Distributed Wireless Scheduling in the SINR Model
Halldorsson, Magnus M
2011-01-01
We study the wireless scheduling problem in the physically realistic SINR model. More specifically: we are given a set of $n$ links, each a sender-receiver pair. We would like to schedule the links using the minimum number of slots, using the SINR model of interference among simultaneously transmitting links. In the basic problem, all senders transmit with the same uniform power. In this work, we provide a distributed $O(\\log n)$-approximation for the scheduling problem, matching the best ratio known for centralized algorithms. This is based on an algorithm studied by Kesselheim and V\\"ocking, improving their analysis by a logarithmic factor. We show this to be best possible for any such distributed algorithm. Our analysis extends also to linear power assignments, and as well as for more general assignments, modulo assumptions about message acknowledgement mechanisms.
Configurational entropy as a bounding of Gauss-Bonnet braneworld models
Correa, R A C; Dutra, A de Souza; de Paula, W; Frederico, T
2016-01-01
Configurational entropy has been revealed as a reliable method for constraining some parameters of a given model [Phys. Rev. D \\textbf{92} (2015) 126005, Eur. Phys. J. C \\textbf{76} (2016) 100]. In this letter we calculate the configurational entropy in Gauss-Bonnet braneworld models. Our results restrict the range of acceptability of the Gauss-Bonnet scalar values. In this way, the information theoretical measure in Gauss-Bonnet scenarios opens a new window to probe situations where the additional parameters, responsible for the Gauss-Bonnet sector, are arbitrary. We also show that such an approach is very important in applications that include p and Dp-branes and various superstring-motivated theories.
Cluster Model for Near-barrier Fusion Induced by Weakly Bound and Halo Nuclei
Beck, C; Keeley, N.; Diaz-Torres, A.
2007-01-01
The influence on the fusion process of coupling transfer/breakup channels is investigated for the medium weight $^{6,7}$Li+$^{59}$Co systems in the vicinity of the Coulomb barrier. Coupling effects are discussed within a comparison of predictions of the Continuum Discretized Coupled-Channels model. Applications to $^{6}$He+$^{59}$Co induced by the borromean halo nucleus $^{6}$He are also proposed.
Bounds on heat transport in Rayleigh's and related models of Bénard convection
Doering, Charles R.; Souza, Andre N.; Wen, Baole; Chini, Gregory P.; Kerswell, Richard R.
2015-11-01
We present new upper limits on convective heat transport in both the full and several low-dimensional Galerkin truncations of Rayleigh's 1916 model of buoyancy-driven Bénard convection using both the so-called background method as well as optimal control variational techniques. Research supported in part by by NSF Awards PHY-1205219, PHY-1338407, PHY-1443836, PHY-1533555 and DMS-1515161.
Variational bounds for a dyadic model of the bilinear Hilbert transform
Do, Yen; Palsson, Eyvindur Ari
2012-01-01
We prove variation-norm estimates for the Walsh model of the truncated bilinear Hilbert transform, extending related results of Lacey, Thiele, and Demeter. The proof uses analysis on the Walsh phase plane and two new ingredients: (i) a variational extension of a lemma of Bourgain by Nazarov-Oberlin-Thiele, and (ii) a variation-norm Rademacher-Menshov theorem of Lewko-Lewko.
Foreign aid and fiscal behavior in a bounded rationality model: Different policy regimes
Gang, Ira N.; Haider Ali Khan
1999-01-01
We examine how the source of foreign aid affects the composition of the recipient government's spending. Does the source of aid - bilateral or multilateral - influence recipient policy-makers' choice between development and nondevelopment expenditure? We depart from previous literature by introducing strong asymmetries in policy-makers' preferences. With the financial constraints set by foreign aid and domestic revenues, this formalization allows us to model and estimate the fiscal behavior o...
Das, Arindam; Okada, Nobuchika; Takahashi, Dai-suke
2016-01-01
We consider the minimal U(1)' extension of the Standard Model (SM) with the classically conformal invariance, where an anomaly free U(1)' gauge symmetry is introduced along with three generations of right-handed neutrinos and a U(1)' Higgs field. Since the classically conformal symmetry forbids all dimensional parameters in the model, the U(1)' gauge symmetry is broken through the Coleman-Weinberg mechanism, generating the mass terms of the U(1)' gauge boson (Z' boson) and the right-handed neutrinos. Through a mixing quartic coupling between the U(1)' Higgs field and the SM Higgs doublet field, the radiative U(1)' gauge symmetry breaking also triggers the breaking of the electroweak symmetry. In this model context, we first investigate the electroweak vacuum instability problem in the SM. Employing the renormalization group equations at the two-loop level and the central values for the world average masses of the top quark ($m_t=173.34$ GeV) and the Higgs boson ($m_h=125.09$ GeV), we perform parameter scans t...
Phase separation in random cluster models I: uniform upper bounds on local deviation
Hammond, Alan
2010-01-01
This is the first in a series of three papers that addresses the behaviour of the droplet that results, in the percolating phase, from conditioning the Fortuin-Kasteleyn random cluster model on the presence of an open dual circuit Gamma_0 encircling the origin and enclosing an area of at least (or exactly) n^2. (By the Fortuin-Kasteleyn representation, the model is a close relative of the droplet formed by conditioning the Potts model on an excess of spins of a given type.) We consider local deviation of the droplet boundary, measured in a radial sense by the maximum local roughness, MLR(Gamma_0), this being the maximum distance from a point in the circuit Gamma_0 to the boundary of the circuit's convex hull; and in a longitudinal sense by what we term maximum facet length, MFL(Gamma_0), namely, the length of the longest line segment of which the boundary of the convex hull is formed. The principal conclusion of the series of papers is the following uniform control on local deviation: that there are positive ...
Lower bound on the pseudoscalar mass in the minimal supersymmetric standard model
International Nuclear Information System (INIS)
In the Higgs sector of the minimal supersymmetric standard model, the mass of the pseudoscalar A is an independent parameter together with tanβ≡v2/v1. If mA is small, then the process e+e-→h+A is kinematically allowed and is suppressed only if tanβ is small, i.e., less than one. On the other hand, the mass of the charged Higgs boson is now near MW, and the decay t→b+h+ is enhanced if tanβA of at least 60 GeV for all values of tanβ. copyright 1997 The American Physical Society
Sufficiency-based Filtering of Invariants for Sequential Equivalence Checking
Hu, Wei
2011-01-01
Verification, as opposed to Testing and Post-Silicon Validation, is a critical step for Integrated Circuits (IC) Design, answering the question â Are we designing the right function?â before the chips are manufactured. One of the core areas of Verification is Equivalence Checking (EC), which is a special yet independent case of Model Checking (MC). Equivalence Checking aims to prove that two circuits, when fed with the same inputs, produce the exact same outputs. There are broadly two ways...
Czech Academy of Sciences Publication Activity Database
Hamilton, A. J.; Novotný, Vojtěch; Waters, E. K.; Basset, Y.; Benke, K. K.; Grimbacher, P. S.; Miller, S. E.; Samuelson, G. A.; Weiblen, G. D.; Yen, J. D. L.; Stork, N. E.
2013-01-01
Roč. 171, č. 2 (2013), s. 357-365. ISSN 0029-8549 R&D Projects: GA MŠk(CZ) LH11008; GA ČR GA206/09/0115 Grant ostatní: Czech Ministry of Education(CZ) CZ.1.07/2.3.00/20.0064; National Science Foundarion(US) DEB-0841885; Otto Kinne Foundation, Darwin Initiative(GB) 19-008 Institutional research plan: CEZ:AV0Z50070508 Institutional support: RVO:60077344 Keywords : host specificity * model * Monte Carlo Subject RIV: EH - Ecology, Behaviour Impact factor: 3.248, year: 2013 http://link.springer.com/article/10.1007%2Fs00442-012-2434-5
Laminar-turbulent patterning in wall-bounded shear flows: a Galerkin model
Seshasayanan, K
2015-01-01
On its way to turbulence, plane Couette flow - the flow between counter-translating parallel plates - displays a puzzling steady oblique laminar-turbulent pattern. We approach this problem via Galerkin modelling of the Navier-Stokes equations. The wall-normal dependence of the hydrodynamic field is treated by means of expansions on functional bases fitting the boundary conditions exactly. This yields a set of partial differential equations for the spatiotemporal dynamics in the plane of the flow. Truncating this set beyond lowest nontrivial order is numerically shown to produce the expected pattern, therefore improving over what was obtained at cruder effective wall-normal resolution. Perspectives opened by the approach are discussed.
Plasma Processes : A self-consistent kinetic modeling of a 1-D, bounded, plasma in equilibrium
Indian Academy of Sciences (India)
Monojoy Goswami; H Ramachandran
2000-11-01
A self-consistent kinetic treatment is presented here, where the Boltzmann equation is solved for a particle conserving Krook collision operator. The resulting equations have been implemented numerically. The treatment solves for the entire quasineutral column, making no assumptions about mfp/, where mfp is the ion-neutral collision mean free path and the size of the device. Coulomb collisions are neglected in favour of collisions with neutrals, and the particle source is modeled as a uniform Maxwellian. Electrons are treated as an inertialess but collisional ﬂuid. The ion distribution function for the trapped and the transiting orbits is obtained. Interesting ﬁndings include the anomalous heating of ions as they approach the presheath, the development of strongly non-Maxwellian features near the last mfp, and strong modiﬁcations of the sheath criterion.
Parameterized Expectations Algorithm and the Moving Bounds: a comment on convergence properties
Pérez, Javier J.; A. Jesús Sánchez
2005-01-01
In this paper we analyze the convergence properties of the moving bounds algorithm to initialize the Parameterized Expectations Algorithm suggested by Maliar and Maliar (2003) [Journal of Business and Economic Statistics 1, pp. 88-92]. We carry out a Monte Carlo experiment to check its performance against some initialization alternatives based on homotopy principles. We do so within the framework of two standard neoclassical growth models. We show that: (i) speed of convergence is poor as com...
Chang, Sanghyeon; Shim, So Young; Song, Jeonghyeon
2012-01-01
In the minimal Universal Extra Dimension (mUED) model, the second Kaluza-Klein (KK) gluon $g^{(2)}$ has loop-induced vertices with the standard model quarks, mediated by the first KK modes of the quark and the gluon/Higgs boson. With a top quark pair, this vertex is enhanced by the cooperation of the strong coupling of a gluon and the large Yukawa coupling of a top quark, leading to substantial branching ratio of $Br(g^{(2)} \\to t \\bar{t}) \\approx 7%-8%$. As the $g^{(2)}$ coupling with a gluon pair is forbidden by the Landau-Yang theorem, $q\\bar{q}\\to g^{(2)}\\to t\\bar{t}$ is the golden mode for the mUED model. Hence the best channel is the $t\\bar{t}$ resonance search in $p\\bar{p}$ collisions. The recent Tevatron data at $\\sqrt{s}=1.96$ TeV with an integrated luminosity of 8.7 fb$^{-1}$ are shown to give the first direct bound on the $g^{(2)}$ mass above 800 GeV. The implication and future prospect at the LHC are discussed also.
The η′N interaction from a chiral effective model and η′-N bound state
International Nuclear Information System (INIS)
The η′ mass reduction in the nuclear medium is expected owing to the degeneracy of the pseudoscalar-singlet and octet mesons in the restoration of the spontaneous chiral symmetry breaking. In this study, we investigate the η′N 2body interaction, which is the fundamental interaction of the in-medium η′ properties, using the linear sigma model as a chiral effective model. The η′N interaction in the linear sigma model comes from the scalar meson exchange with U A(1) symmetry effect and is found to be fairly strong attraction. The transition amplitude of η′N to the ηN channel is relatively small compared to that of elastic channel. From the analysis of the η′N 2body system, we find a η′N bound state with the binding energy 12.3-3.3iMeV. We expect that this strongly attractive two body interaction leads to a deep and attractive optical potential
Rodríguez, David; Ranganathan, Anirudh; Carlsson, Jens
2014-07-28
The recent increase in the number of atomic-resolution structures of G protein-coupled receptors (GPCRs) has contributed to a deeper understanding of ligand binding to several important drug targets. However, reliable modeling of GPCR-ligand complexes for the vast majority of receptors with unknown structure remains to be one of the most challenging goals for computer-aided drug design. The GPCR Dock 2013 assessment, in which researchers were challenged to predict the crystallographic structures of serotonin 5-HT(1B) and 5-HT(2B) receptors bound to ergotamine, provided an excellent opportunity to benchmark the current state of this field. Our contributions to GPCR Dock 2013 accurately predicted the binding mode of ergotamine with RMSDs below 1.8 Å for both receptors, which included the best submissions for the 5-HT(1B) complex. Our models also had the most accurate description of the binding sites and receptor-ligand contacts. These results were obtained using a ligand-guided homology modeling approach, which combines extensive molecular docking screening with incorporation of information from multiple crystal structures and experimentally derived restraints. In this work, we retrospectively analyzed thousands of structures that were generated during the assessment to evaluate our modeling strategies. Major contributors to accuracy were found to be improved modeling of extracellular loop two in combination with the use of molecular docking to optimize the binding site for ligand recognition. Our results suggest that modeling of GPCR-drug complexes has reached a level of accuracy at which structure-based drug design could be applied to a large number of pharmaceutically relevant targets. PMID:25030302
Bounds on quantum gravity parameter from the $SU(2)$ NJL effective model of QCD
Nozari, K; Gorji, M A
2015-01-01
Existence of a minimal measurable length, as an effective cutoff in the ultraviolet regime, is a common feature of all approaches to the quantum gravity proposal. It is widely believed that this length scale will be of the order of the Planck length $\\lambda=\\lambda_0\\,l_{_{\\rm Pl}}$, where $\\lambda_0\\sim{\\mathcal O}(1)$ is a dimensionless parameter that should be fixed only by the experiments. This issue can be taken into account through the deformed momentum spaces with compact topologies. In this paper, we consider minimum length effects on the physical quantities related to three parameters of the $SU(2)$ Nambu-Jona-Lasinio effective model of QCD by means of the deformed measure which is defined on compact momentum space with ${\\mathbf S}^3$ topology. This measure is suggested by the doubly special relativity theories, Snyder deformed spaces, and the deformed algebra that is obtained in the light of the stability theory of Lie algebras. Using the current experimental data of the particle physics collabora...
Scram system with continuos check
International Nuclear Information System (INIS)
The equipment described pretends to be a further step to the use of integrated circuits in nuclear instrumentation, considering that this type of control was traditionally carried out on the bases of electromechanical elements. A continuous self-check method has been applied in accordance with the high reliability requiered for this type of equipments. The developed equipment fulfils the condition that any deficiency in its component elements, causes an anormal self-detected operation. The equipment covers two systems: the Scram one, that includes the sequence generator-detector, the rods check and scram chain, and the Check system that uses pulses from the sequence detector. (author)
New methods of concurrent checking
Goessel, Michael; Sogomonyan, Egor; Marienfeld, Daniel
2008-01-01
Written by a team of two leading experts and two very successful young former PhD students, New Methods of Concurrent Checking describes new methods of concurrent checking, such as partial duplication, use of output dependencies, complementary circuits, self-dual parity, self-dual duplication and others. A special chapter demonstrates how the new general methods of concurrent checking can be more specifically applied to regular structures to obtain optimum results. This is exemplified for all types of adders up to 64 bits with a level of detail never before presented in the literature. The cle
Alexander, Karyn E; Brijnath, Bianca; Mazza, Danielle
2014-01-01
Background More than a fifth of Australian children arrive at school developmentally vulnerable. To counteract this, the Healthy Kids Check (HKC), a one-off health assessment aimed at preschool children, was introduced in 2008 into Australian general practice. Delivery of services has, however, remained low. The Theoretical Domains Framework, which provides a method to understand behaviours theoretically, can be condensed into three core components: capability, opportunity and motivation, and...
Bounds on the Threshold of Linear Programming Decoding
Vontobel, Pascal O.; Koetter, Ralf
2006-01-01
Whereas many results are known about thresholds for ensembles of low-density parity-check codes under message-passing iterative decoding, this is not the case for linear programming decoding. Towards closing this knowledge gap, this paper presents some bounds on the thresholds of low-density parity-check code ensembles under linear programming decoding.
A model of charmed baryon-nucleon potential and 2- and 3-body bound states with charmed baryon
Maeda, Saori; Yokota, Akira; Hiyama, Emiko; Liu, Yan-Rui
2015-01-01
Potential models of the interaction between a charmed baryon ($Y_c$) and the nucleon ($N$) are constructed on the basis of a long-range meson ($\\pi$ and $\\sigma$) exchange potential as well as a short-distance quark exchange interaction. The quark cluster model is used to evaluate the short-range repulsion between $Y_c$ and $N$, while the meson exchange potentials are modified by a form factor at short distances. We determine the cutoff parameters of the form factors so as to fit the $NN$ scattering data with the same approach. The ground state charmed baryons, $\\Lambda_c$, $\\Sigma_c$ and $\\Sigma_c^*$, are included as $Y_c$, and channel couplings of relevant $Y_c N$ channels are taken into account. We propose four sets of parameters (a -- d), among which the most attractive potential (d) predicts bound $\\Lambda_c N$ $J^\\pi= 0^+$ and $1^+$ states. In order to apply the potential to a many-body problem, we construct an effective $\\Lambda_c N$ one-channel potential for the parameter set (d). It is applied to the...
Treasury Check Verification Query (TCVQ)
Social Security Administration — The TCVQ system determines the SSN of an individual whose check has been returned to a local field office. The FO is able to request this information via the TCVQ...
Community perspectives: Community check cashing
Daniel Leibsohn
2011-01-01
In May of 2009, Community Development Finance (CDF) opened the first nonprofit, full-service check cashing store in the country in Fruitvale, California. The project is designed to provide low-income households with the financial services they need, without the asset-stripping characteristics common to the fringe banking industry. In addition to providing affordable check cashing services and a payday loan product, CDF also provides financial coaching and literacy training, small business ass...
Body checking behaviors in men
Walker, D. Catherine; Anderson, Drew A.; Hildebrandt, Thomas
2009-01-01
Males have been facing increasing pressure from the media to attain a lean, muscular physique, and are at risk for body dissatisfaction, disturbed eating and exercise behaviors, and abuse of appearance- and performance-enhancing drugs (APEDs). The aim of the current study was to examine the relationship between body checking and mood, symptoms of muscle dysmorphia, importance of shape and weight, and APED use in undergraduate males. Body checking in males was correlated with weight and shape ...
Towards Secure Distance Bounding
Boureanu, Ioana; Mitrokotsa, Aikaterini; Vaudenay, Serge
2013-01-01
Relay attacks (and, more generally, man-in-the-middle attacks) are a serious threat against many access control and payment schemes. In this work, we present distance-bounding protocols, how these can deter relay attacks, and the security models formalizing these protocols. We show several pitfalls making existing protocols insecure (or at least, vulnerable, in some cases). Then, we introduce the SKI protocol which enjoys resistance to all popular attack-models and features provable security....
Static Checking of Interrupt-driven Software
DEFF Research Database (Denmark)
Brylow, Dennis; Damgaard, Niels; Palsberg, Jens
2001-01-01
Resource-constrained devices are becoming ubiquitous. Examples include cell phones, palm pilots, and digital thermostats. It can be difficult to fit required functionality into such a device without sacrificing the simplicity and clarity of the software. Increasingly complex embedded systems...... require extensive brute-force testing, making development and maintenance costly. This is particularly true for system components that are written in assembly language. Static checking has the potential of alleviating these problems, but until now there has been little tool support for programming at the...... assembly level. In this paper we present the design and implementation of a static checker for interrupt-driven Z86-based software with hard real-time requirements. For six commercial microcontrollers, our checker has produced upper bounds on interrupt latencies and stack sizes, as well as verified...
基于有限理性智能体的生态经济模型%The Ecological Economic Model Based on Bounded Rational Agents
Institute of Scientific and Technical Information of China (English)
姜继娇
2005-01-01
From the view of hominine bounded rationalities, this paper analyzes the important relationships between ecology and economics with behavioral finance. With a different focus, this paper adopts a new conceptualization of stock to show how this conceptualization leads to a new measure of the interaction between ecology and economics, based on bounded rational agents. The hierarchical structure of ecological economic system is described with a multi-agent simulation program. This paper also develops an ecological economic model, in which behavioral finance theories are applied to simulating the dynamics system. With the model, this paper confirms that macro-level indicators of sustainability are predictably influenced by behaviors of bounded rational agents at the micro-level. We discuss the significance of these findings in order to better understand the ecological-economic system based on behavioral finance.
International Nuclear Information System (INIS)
We present a general discussion of the unitarity triangle from εK, ΔMd,s and K → πν anti ν in models with minimal flavour violation (MFV), allowing for arbitrary signs of the generalized Inami-Lim functions Ftt and X relevant for (εK, ΔMd,s) and K → πν anti ν, respectively. The models in which Ftt has a sign opposite to the one in the standard model, i.e. Ftt K, ΔMd,s) imply an absolute lower bound on the Bd → ψKS CP asymmetry aψKS of 0.69, which is substantially stronger than in the case of Ftt > 0. We find absolute lower and upper bounds on the branching ratio Br(KL → π0ν anti ν) as functions of Br(K+ → π+ν anti ν). Moreover, we point out that for given Br(K+ → π+ν anti ν) and aψKS only two values for Br(KL → π0ν anti ν), corresponding to the two signs of X, are possible in the full class of MFV models, independently of any new parameters arising in these models. The present upper bounds on Br(K+ → π+ν anti ν) and vertical stroke Vub/Vcb vertical stroke imply the absolute upper bound Br(KL → π0ν anti ν) -10 (90% C.L.). (orig.)
Check Verbraucherpolitik und Verbraucherbeteiligung
DEFF Research Database (Denmark)
Hagen, Kornelia; Micklitz, Hans-W.; Oehler, Andreas;
2013-01-01
information-seeking consumer. Yet, both everyday practice and research in behavioural economics show that this view lacks empirical ground. In fact, there are different consumer types and different forms of rationalities at work. Effective consumer policy making should be based on the empirically revealed......The paper discusses the opportunities for an empirically grounded decision support system as an instrument for independent and scientifically based consumer policy consulting. To date, consumer policy is dominated by the information paradigm and the leitbild of the rational, sovereign and...... behaviour of consumers, not on an ideal model. Moreover, it is often not clear how much consumer policy measures actually contribute to the consumer interest, and whether there would be more effective and efficient policy instruments to strengthen the consumer position. The authors suggest introducing an...
International Nuclear Information System (INIS)
We present high-precision trap loss spectroscopy of excited Na2 molecules obtained by the photoassociation of ultracold sodium atoms. Near the 3 2S+3 2P3/2 dissociation limit, hyperfine and rotational (Coriolis-type) interactions cause significant mixing of states of different nominal Hund's case (c) symmetry resulting in a complex pattern of spectral lines. We construct a theoretical model of the large, slowly rotating molecule starting from a long-range, atomic viewpoint. Interaction potentials are derived from the known long-range resonant dipole and van der Waals forces between atoms, supplemented at short range by the results of ab initio electronic-structure calculations. Spin-dependent interactions coupling the various angular momenta--nuclear spin, electron spin, electron orbit, and the mechanical rotation of the molecule as a whole--are derived from known atomic parameters. We avoid imposing approximate symmetries or coupling schemes and consequently include all nonadiabatic mixing of different degrees of freedom. Quantitative agreement between experiment and theory for both line positions and intensities is found. Specifically, we observe and calculate mixing of levels of 0g-, 0u+, and 1g symmetry bound by 2S+3 2P3/2 asymptote
Yang, Kuo-Shu
2003-01-01
Maslow's theory of basic human needs is criticized with respect to two of its major aspects, unidimensional linearity and cross-cultural validity. To replace Maslow's linear theory, a revised Y model is proposed on the base of Y. Yu's original Y model. Arranged on the stem of the Y are Maslow's physiological needs (excluding sexual needs) and safety needs. Satisfaction of these needs is indispensable to genetic survival. On the left arm of the Y are interpersonal and belongingness needs, esteem needs, and the self-actualization need. The thoughts and behaviors required for the fulfillment of these needs lead to genetic expression. Lastly, on the right arm of the Y are sexual needs, childbearing needs, and parenting needs. The thoughts and behaviors entailed in the satisfaction of these needs result in genetic transmission. I contend that needs for genetic survival and transmission are universal and that needs for genetic expression are culture-bound. Two major varieties of culture-specific expression needs are distinguished for each of the three levels of needs on the left arm of the Y model. Collectivistic needs for interpersonal affiliation and belongingness, esteem, and self-actualization prevail in collectivist cultures like those found in East Asian countries. Individualistic needs are dominant in individualist cultures like those in North America and certain European nations. I construct two separate Y models, one for people in collectivist cultures and the other for those in individualist ones. In the first (the Yc model), the three levels of expression needs on the left arm are collectivistic in nature, whereas in the second (the Yi model), the three levels of needs on the left arm are individualistic in nature. Various forms of the double-Y model are formulated by conceptually combining the Yc and Yi models at the cross-cultural, crossgroup, and intra-individual levels. Research directions for testing the various aspects of the double-Y model are
Matthews, Edward; Sen, Ananya; Yoshikawa, Naruo; Bergström, Ed; Dessent, Caroline E H
2016-06-01
Isolated molecular clusters of adenine, cytosine, thymine and uracil bound to hexachloroplatinate, PtCl6(2-), have been studied using laser electronic photodissociation spectroscopy to investigate photoactivation of a platinum complex in the vicinity of a nucleobase. These metal complex-nucleobase clusters represent model systems for identifying the fundamental photochemical processes occurring in photodynamic platinum drug therapies that target DNA. This is the first study to explore the specific role of a strongly photoactive platinum compound in the aggregate complex. Each of the clusters studied displays a broadly similar absorption spectra, with a strong λmax ∼ 4.6 eV absorption band and a subsequent increase in the absorption intensity towards higher spectral-energy. The absorption bands are traced to ligand-to-metal-charge-transfer excitations on the PtCl6(2-) moiety within the cluster, and result in Cl(-)·nucleobase and PtCl5(-) as primary photofragments. These results demonstrate how selective photoexcitation can drive distinctive photodecay channels for a model photo-pharmaceutical. In addition, cluster absorption due to excitation of nucleobase-centred chromophores is observed in the region around 5 eV. For the uracil cluster, photofragments consistent with ultrafast decay of the excited state and vibrational predissociation on the ground-state surface are observed. However, this decay channel becomes successively weaker on going from thymine to cytosine to adenine, due to differential coupling of the excited states to the electron detachment continuum. These effects demonstrate the distinctive photophysical characteristics of the different nucleobases, and are discussed in the context of the recently recorded photoelectron spectra of theses clusters. PMID:27198464
Complex bounds for multimodal maps: bounded combinatorics
Smania, Daniel
2000-01-01
We proved the so called complex bounds for multimodal, infinitely renormalizable analytic maps with bounded combinatorics: deep renormalizations have polynomial-like extensions with definite modulus. The complex bounds is the first step to extend the renormalization theory of unimodal maps to multimodal maps.
KETENCI, Uktu Gorkem; Bremond, Roland; Auberlet, Jean Michel; GRISLIN, Emmanuelle
2010-01-01
There are two kinds of perception : active and passive. This paper is an attempt to take advantage of active perception to improve the agent's perception of relevant information. Through the data filtering capacity, active perception is a useful tool for modeling human-like bounded perception. Using such filters, either the agent or the environment take an active role. We determine several unsolved issues in active perception and do several proposals to implement our concept on the active per...
International Nuclear Information System (INIS)
We obtain bounds on the anomalous magnetic and electric dipole moments of the tau-neutrino through the reaction e+e-→ννγ at the Z1-pole in the framework of a Left-Right symmetric model and a class of E6 inspired models with an additional neutral vector boson Zθ. We use the data collected by the L3 Collaboration at LEP. For the parameters of the E6 model we consider the mixing angle θE6=37.8 deg. and MZθ=7MZ1. We find that our bounds are of the same order of magnitude as those obtained in other extensions of the standard model
Upper Bounds on Numerical Approximation Errors
DEFF Research Database (Denmark)
Raahauge, Peter
2004-01-01
This paper suggests a method for determining rigorous upper bounds on approximationerrors of numerical solutions to infinite horizon dynamic programming models.Bounds are provided for approximations of the value function and the policyfunction as well as the derivatives of the value function. The...... approximations of a standard (strictly concave)growth model.KEYWORDS: Numerical approximation errors, Bellman contractions, Error bounds...
Keilani, Serene; Lun, Yi; Stevens, Anthony C; Williams, Hadis N; Sjoberg, Eric R; Khanna, Richie; Valenzano, Kenneth J; Checler, Frederic; Buxbaum, Joseph D; Yanagisawa, Katsuhiko; Lockhart, David J; Wustman, Brandon A; Gandy, Sam
2012-04-11
Alterations in the lipid composition of endosomal-lysosomal membranes may constitute an early event in Alzheimer's disease (AD) pathogenesis. In this study, we investigated the possibility that GM2 ganglioside accumulation in a mouse model of Sandhoff disease might be associated with the accumulation of intraneuronal and extracellular proteins commonly observed in AD. Our results show intraneuronal accumulation of amyloid-β peptide (Aβ)-like, α-synuclein-like, and phospho-tau-like immunoreactivity in the brains of β-hexosaminidase knock-out (HEXB KO) mice. Biochemical and immunohistochemical analyses confirmed that at least some of the intraneuronal Aβ-like immunoreactivity (iAβ-LIR) represents amyloid precursor protein C-terminal fragments (APP-CTFs) and/or Aβ. In addition, we observed increased levels of Aβ40 and Aβ42 peptides in the lipid-associated fraction of HEXB KO mouse brains, and intraneuronal accumulation of ganglioside-bound Aβ (GAβ) immunoreactivity in a brain region-specific manner. Furthermore, α-synuclein and APP-CTFs and/or Aβ were found to accumulate in different regions of the substantia nigra, indicating different mechanisms of accumulation or turnover pathways. Based on the localization of the accumulated iAβ-LIR to endosomes, lysosomes, and autophagosomes, we conclude that a significant accumulation of iAβ-LIR may be associated with the lysosomal-autophagic turnover of Aβ and fragments of APP-containing Aβ epitopes. Importantly, intraneuronal GAβ immunoreactivity, a proposed prefibrillar aggregate found in AD, was found to accumulate throughout the frontal cortices of postmortem human GM1 gangliosidosis, Sandhoff disease, and Tay-Sachs disease brains. Together, these results establish an association between the accumulation of gangliosides, autophagic vacuoles, and the intraneuronal accumulation of proteins associated with AD. PMID:22496568
International Nuclear Information System (INIS)
This research concerns with the development of a linear three-dimensional numerical model in a quantum environment. We use the semi inverse variational method together with B-spline bases to extract the structures of bound states of the Schrödinger equation. The model performances are demonstrated for the Coulomb type problem. From realistic examples, some state configurations are presented to illustrate the effectiveness and the exactitude of the proposed method. (general)
Mazumder, Nairwita; Chakraborty, Subenoy
2010-01-01
In this letter, we investigate the validity of the generalized second law of thermodynamics of the universe bounded by the event horizon in the holographic dark energy model. The universe is chosen to be homogeneous and isotropic and the validity of the first law has been assumed here. The matter in the universe is taken in the form of non-interacting two fluid system- one component is the holographic dark energy model and the other component is in the form of dust.
Advanced techniques for efficient data integrity checking
DEFF Research Database (Denmark)
Martinenghi, Davide
Integrity constraint checking, understood as the verification of data correctness and well-formedness conditions that must be satisfied in any state of a database, is not fully supported by current database technology. In a typical scenario, a database is required to comply with given semantic cr...... contexts, such as recursive databases, concurrent database systems, data integration systems and XML document collections, and provide a performance evaluation of the proposed model.......Integrity constraint checking, understood as the verification of data correctness and well-formedness conditions that must be satisfied in any state of a database, is not fully supported by current database technology. In a typical scenario, a database is required to comply with given semantic...... criteria (the integrity constraints) and to maintain the compliance each time data are updated. Since the introduction of the SQL2 standard, the SQL language started supporting assertions, which allow one to define general data consistency requirements expressing arbitrarily complex “business rules” that...
From preventive to permissive checks
DEFF Research Database (Denmark)
Weisdorf, Jacob Louis; Sharp, Paul Richard
2009-01-01
The Malthusian "preventive check" mechanism has been well documented for pre-industrial England through evidence for a negative correlation between the marriage rate and the price of wheat. Other literature, however, speculates that the correlation was in fact positive from the early nineteenth...
DEFF Research Database (Denmark)
Damgård, Ivan Bjerre; Faust, Sebastian; Mukherjee, Pratyay; Venturi, Daniele
Related key attacks (RKAs) are powerful cryptanalytic attacks where an adversary can change the secret key and observe the effect of such changes at the output. The state of the art in RKA security protects against an a-priori unbounded number of certain algebraic induced key relations, e...... bounded tamper and leakage resilient CCA secure public key cryptosystem based on the DDH assumption. We first define a weaker CPA-like security notion that we can instantiate based on DDH, and then we give a general compiler that yields CCA-security with tamper and leakage resilience. This requires a...... public tamper-proof common reference string. Finally, we explain how to boost bounded tampering and leakage resilience (as in 1. and 2. above) to continuous tampering and leakage resilience, in the so-called floppy model where each user has a personal hardware token (containing leak- and tamper...
Garcilazo, H
2016-01-01
We have used realistic local interactions based on the recent update of the strangeness $-2$ Nijmegen ESC08c potential to calculate the bound state problem of the $\\Xi NN$ system in the $(I)J^P=(\\frac{1}{2})\\frac{3}{2}^+$ state. We found that this system presents a deeply bound state lying $13.5$ MeV below the $\\Xi d$ threshold. Since in lowest order, pure S$-$wave configuration, this system can not decay into the open $\\Lambda\\Lambda N$ channel, its decay width is expected to be very small. We have also recalculated the $(I)J^P=(\\frac{3}{2})\\frac{1}{2}^+$ state and we have compared with results of quark-model based potentials.
Transaction management with integrity checking
DEFF Research Database (Denmark)
Martinenghi, Davide; Christiansen, Henning
2005-01-01
Database integrity constraints, understood as logical conditions that must hold for any database state, are not fully supported by current database technology. It is typically up to the database designer and application programmer to enforce integrity via triggers or tests at the application level......, which are difficult to maintain and error prone. Two important aspects must be taken care of. 1.~It is too time consuming to check integrity constraints from scratch after each update, so simplified checks before each update should be used relying on the assumption that the current state is consistent....... 2.~In concurrent database systems, besides the traditional correctness criterion, the execution schedule must ensure that the different transactions can overlap in time without destroying the consistency requirements tested by other, concurrent transactions....
From Preventive to Permissive Checks
DEFF Research Database (Denmark)
Sharp, Paul Richard; Weisdorf, Jacob Louis
The Malthusian "preventive check" mechanism has been well documented for pre-industrial England through evidence for a negativcorrelation between the marriage rate and the price of wheat. Other literature, however, speculates that the correlation was in fact positive from the early nineteenth cen...... shows that this result is not in fact inconsistent with a stylized Malthusian mechanism, and can be understood within the context of an increasing dominance of shocks to aggregate demand rather than to aggregate supply...
Checking modes of HAL programs
de la Banda, MG; Harvey, W; Marriott, K.; Stuckey, PJ; Demoen, Bart
2005-01-01
Recent constraint logic programming (CLP) languages, such as HAL and Mercury, require type, mode and determinism declarations for predicates. This information allows the generation of efficient target code and the detection of many errors at compile-time. Unfortunately, mode checking in such languages is difficult. One of the main reasons is that, for each predicate mode declaration, the compiler is required to appropriately re-order literals in the predicate's definition. The task is further...
Diaz-Torres, Alexis
2007-01-01
A self-contained Fortran-90 program based on a classical trajectory model with stochastic breakup is presented, which should be a powerful tool for quantifying complete and incomplete fusion, and breakup in reactions induced by weakly-bound two-body projectiles near the Coulomb barrier. The code calculates complete and incomplete fusion cross sections and their angular momentum distribution, as well as breakup observables (angle, kinetic energy and relative energy distributions).
Bounds on Integrals of the Wigner Function
Bracken, A J; Wood, J G
1999-01-01
The integral of the Wigner function over a subregion of the phase-space of a quantum system may be less than zero or greater than one. It is shown that for systems with one degree of freedom, the problem of determining the best possible upper and lower bounds on such an integral, over all possible states, reduces to the problem of finding the greatest and least eigenvalues of an hermitian operator corresponding to the subregion. The problem is solved exactly in the case of an arbitrary elliptical region. These bounds provide checks on experimentally measured quasiprobability distributions.