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.
Compositional encoding for bounded model checking
Institute of Scientific and Technical Information of China (English)
Jun SUN; Yang LIU; Jin Song DONG; Jing SUN
2008-01-01
Verification techniques like SAT-based bounded model checking have been successfully applied to a variety of system models. Applying bounded model checking to compositional process algebras is, however, a highly non-trivial task. One challenge is that the number of system states for process algebra models is not statically known, whereas exploring the full state space is computa-tionally expensive. This paper presents a compositional encoding of hierarchical processes as SAT problems and then applies state-of-the-art SAT solvers for bounded model checking. The encoding avoids exploring the full state space for complex systems so as to deal with state space explosion. We developed an automated analyzer which combines complementing model checking tech-niques (I.e., bounded model checking and explicit on-the-fly model checking) to validate system models against event-based temporal properties. The experiment results show the analyzer handles large systems.
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.
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.
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.
Tarmo: A Framework for Parallelized Bounded Model Checking
Wieringa, Siert; Heljanko, Keijo; 10.4204/EPTCS.14.5
2009-01-01
This paper investigates approaches to parallelizing Bounded Model Checking (BMC) for shared memory environments as well as for clusters of workstations. We present a generic framework for parallelized BMC named Tarmo. Our framework can be used with any incremental SAT encoding for BMC but for the results in this paper we use only the current state-of-the-art encoding for full PLTL. Using this encoding allows us to check both safety and liveness properties, contrary to an earlier work on distributing BMC that is limited to safety properties only. Despite our focus on BMC after it has been translated to SAT, existing distributed SAT solvers are not well suited for our application. This is because solving a BMC problem is not solving a set of independent SAT instances but rather involves solving multiple related SAT instances, encoded incrementally, where the satisfiability of each instance corresponds to the existence of a counterexample of a specific length. Our framework includes a generic architecture for a ...
Tarmo: A Framework for Parallelized Bounded Model Checking
Directory of Open Access Journals (Sweden)
Siert Wieringa
2009-12-01
Full Text Available This paper investigates approaches to parallelizing Bounded Model Checking (BMC for shared memory environments as well as for clusters of workstations. We present a generic framework for parallelized BMC named Tarmo. Our framework can be used with any incremental SAT encoding for BMC but for the results in this paper we use only the current state-of-the-art encoding for full PLTL. Using this encoding allows us to check both safety and liveness properties, contrary to an earlier work on distributing BMC that is limited to safety properties only. Despite our focus on BMC after it has been translated to SAT, existing distributed SAT solvers are not well suited for our application. This is because solving a BMC problem is not solving a set of independent SAT instances but rather involves solving multiple related SAT instances, encoded incrementally, where the satisfiability of each instance corresponds to the existence of a counterexample of a specific length. Our framework includes a generic architecture for a shared clause database that allows easy clause sharing between SAT solver threads solving various such instances. We present extensive experimental results obtained with multiple variants of our Tarmo implementation. Our shared memory variants have a significantly better performance than conventional single threaded approaches, which is a result that many users can benefit from as multi-core and multi-processor technology is widely available. Furthermore we demonstrate that our framework can be deployed in a typical cluster of workstations, where several multi-core machines are connected by a network.
Applied Bounded Model Checking for Interlocking System Designs
DEFF Research Database (Denmark)
Haxthausen, Anne Elisabeth; Peleska, Jan; Pinger, Ralf
2014-01-01
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...
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...
Bounded Model Checking and Inductive Verification of Hybrid Discrete-Continuous Systems
DEFF Research Database (Denmark)
Becker, Bernd; Behle, Markus; Eisenbrand, Fritz
2004-01-01
We present a concept to signicantly advance the state of the art for bounded model checking (BMC) and inductive verication (IV) of hybrid discrete-continuous systems. Our approach combines the expertise of partners coming from dierent domains, like hybrid systems modeling and digital circuit...... 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...
Local Model Checking of Weighted CTL with Upper-Bound Constraints
DEFF Research Database (Denmark)
Jensen, Jonas Finnemann; Larsen, Kim Guldstrand; Srba, Jiri
2013-01-01
graphs. We implement all algorithms in a publicly available tool prototype and evaluate them on several experiments. The principal conclusion is that our local algorithm is the most efficient one with an order of magnitude improvement for model checking problems with a high number of “witnesses”.......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...
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...
Li, X Y; Yang, G W; Zheng, D S; Guo, W S; Hung, W N N
2015-01-01
Genetic regulatory networks are the key to understanding biochemical systems. One condition of the genetic regulatory network under different living environments can be modeled as a synchronous Boolean network. The attractors of these Boolean networks will help biologists to identify determinant and stable factors. Existing methods identify attractors based on a random initial state or the entire state simultaneously. They cannot identify the fixed length attractors directly. The complexity of including time increases exponentially with respect to the attractor number and length of attractors. This study used the bounded model checking to quickly locate fixed length attractors. Based on the SAT solver, we propose a new algorithm for efficiently computing the fixed length attractors, which is more suitable for large Boolean networks and numerous attractors' networks. After comparison using the tool BooleNet, empirical experiments involving biochemical systems demonstrated the feasibility and efficiency of our approach.
Institute of Scientific and Technical Information of China (English)
Wanwei LIU; Ji WANG; Huowang CHEN; Xiaodong MA; Zhaofei WANG
2009-01-01
Property specification language (PSL) is a specification language which has been accepted as an industrial standard. In PSL, SEREs are used as additional formula constructs. In this paper, we present a variant of PSL, namely APSL, which replaces SEREs with finite automata. APSL and PSL are of the exactly same expressiveness. Then, we extend the LTL symbolic model checking algorithm to that of APSL, and then present a tableau based APSL verification technique, which can be easily implemented via the BDD based symbolic approach. Moreover, we implement an extension of NuSMV, and this adapted version supports symbolic model checking of APSL. Experimental results show that this variant of PSL can be efficiently verified. Henceforth, symbolic model checking PSL can be carried out by a transformation from PSL to APSL and symbolic model checking APSL.
Parallel Software Model Checking
2015-01-08
JAN 2015 2. REPORT TYPE N/A 3. DATES COVERED 4. TITLE AND SUBTITLE Parallel Software Model Checking 5a. CONTRACT NUMBER 5b. GRANT NUMBER...AND ADDRESS(ES) Software Engineering Institute Carnegie Mellon University Pittsburgh, PA 15213 8. PERFORMING ORGANIZATION REPORT NUMBER 9...3: ∧ ≥ 10 ∧ ≠ 10 ⇒ : Parallel Software Model Checking Team Members Sagar Chaki, Arie Gurfinkel
Monteiro, Felipe R.
2016-01-01
The extensive use of digital controllers demands a growing effort to prevent design errors that appear due to finite-word length (FWL) effects. However, there is still a gap, regarding verification tools and methodologies to check implementation aspects of control systems. Thus, the present paper describes an approach, which employs bounded model checking (BMC) techniques, to verify fixed-point digital controllers represented by state-space equations. The experimental results demonstrate the ...
Model Checking Feature Interactions
DEFF Research Database (Denmark)
Le Guilly, Thibaut; Olsen, Petur; Pedersen, Thomas;
2015-01-01
This paper presents an offline approach to analyzing feature interactions in embedded systems. The approach consists of a systematic process to gather the necessary information about system components and their models. The model is first specified in terms of predicates, before being refined to t...... to timed automata. The consistency of the model is verified at different development stages, and the correct linkage between the predicates and their semantic model is checked. The approach is illustrated on a use case from home automation....
DEFF Research Database (Denmark)
Andersen, Henrik Reif
1995-01-01
A major obstacle in applying finite-state model checking to the verification of large systems is the combinatorial explosion of the state space arising when many loosely coupled parallel processes are considered. The problem also known as the state-explosion problem has been attacked from various...... sides. This paper presents a new approach based on partial model checking where parts of the concurrent system are gradually removed while transforming the specification accordingly. When the intermediate specifications constructed in this manner can be kept small, the state-explosion problem is avoided....... Experimental results with a prototype implemented in Standard ML, shows that for Milner's Scheduler-an often used benchmark-this approach improves on the published results on binary decision diagrams and is comparable to results obtained using generalized decision diagrams. Specifications are expressed...
Beyer, Dirk; Keremoglu, M Erkan; Wendler, Philipp
2011-01-01
Software model checking, as an undecidable problem, has three possible outcomes: (1) the program satisfies the specification, (2) the program does not satisfy the specification, and (3) the model checker fails. The third outcome usually manifests itself in a space-out, time-out, or one component of the verification tool giving up; in all of these failing cases, significant computation is performed by the verification tool before the failure, but no result is reported. We propose to reformulate the model-checking problem as follows, in order to have the verification tool report a summary of the performed work even in case of failure: given a program and a specification, the model checker returns a condition P ---usually a state predicate--- such that the program satisfies the specification under the condition P ---that is, as long as the program does not leave states in which P is satisfied. We are of course interested in model checkers that return conditions P that are as weak as possible. Instead of outcome ...
Completeness of bounded model checking temporal logic of knowledge%知识时态逻辑有界模型检测中的完备性
Institute of Scientific and Technical Information of China (English)
刘志锋; 葛云; 章东; 周从华
2010-01-01
In order to find the completeness threshold which offers a practical method of making bounded model checking complete, the over-approximation for the complete threshold is presented. First, a linear logic of knowledge is introduced into the past tense operator, and then a new temporal epistemic logic LTLKP is obtained, so that LTLKP can naturally and precisely describe the calculate the maximal reachable depth and the length of the longest of loop free paths in the structure based on the graph structure theory. Finally, some theorems are proposed to show how to approximate the complete threshold with the diameter and recurrence diameter. The proposed work resolves the completeness threshold problem so that the completeness of bounded model checking can be guaranteed.%为解决限界模型检测的完备性问题, 研究了完全界的计算问题,给出了完全界的上近似计算.首先,在线性时态认知逻辑中引入过去时态算子,得到新的时态认知逻辑LTLKP,从而可以紧凑自然地描述系统的可靠性规范;其次,依据图结构理论, 设计了一套深度优先算法计算出系统的最大可达深度和最长无循环路径的长度;最后,以定理的形式给出了最大可达深度和最长无循环路径的长度与完全界的关系,得出了完全界的一种上近似估算.所做工作有效地解决了限界模型检测中的完全界计算问题,从而保证了限界模型检测的完备性.
Semantic Importance Sampling for Statistical Model Checking
2015-01-16
approach called Statistical Model Checking (SMC) [16], which relies on Monte - Carlo -based simulations to solve this verification task more scalably...Conclusion Statistical model checking (SMC) is a prominent approach for rigorous analysis of stochastic systems using Monte - Carlo simulations. In this... Monte - Carlo simulations, for computing the bounded probability that a specific event occurs during a stochastic system’s execution. Estimating the
Model Checking as Static Analysis
DEFF Research Database (Denmark)
Zhang, Fuyuan
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...... 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......-calculus can be encoded as the intended model of SFP. Our research results have strengthened the link between model checking and static analysis. This provides a theoretical foundation for developing a unied tool for both model checking and static analysis techniques....
Compositional and Quantitative Model Checking
DEFF Research Database (Denmark)
Larsen, Kim Guldstrand
2010-01-01
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...
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...
Coverage Metrics for Model Checking
Penix, John; Visser, Willem; Norvig, Peter (Technical Monitor)
2001-01-01
When using model checking to verify programs in practice, it is not usually possible to achieve complete coverage of the system. In this position paper we describe ongoing research within the Automated Software Engineering group at NASA Ames on the use of test coverage metrics to measure partial coverage and provide heuristic guidance for program model checking. We are specifically interested in applying and developing coverage metrics for concurrent programs that might be used to support certification of next generation avionics software.
The Complexity of Model Checking Higher-Order Fixpoint Logic
DEFF Research Database (Denmark)
Axelsson, Roland; Lange, Martin; Somla, Rafal
2007-01-01
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 corollary...... provides complexity results for its model checking problem. In particular we consider its fragments HFLk,m which are formed using types of bounded order k and arity m only. We establish k-ExpTime-completeness for model checking each HFLk,m fragment. For the upper bound we reduce the problem to the problem...
Distefano, Dino; Katoen, Joost-Pieter; Rensink, Arend
2000-01-01
This paper presents a logic, called BOTL (Object-Based Temporal Logic), that facilitates the specification of dynamic and static properties of object-based systems. The logic is based on the branching temporal logic CTL and the Object Constraint Language (OCL). Eventually, the aim is to do model che
Program Analysis as Model Checking
DEFF Research Database (Denmark)
Olesen, Mads Chr.
and abstract interpretation. Model checking views the program as a finite automaton and tries to prove logical properties over the automaton model, or present a counter-example if not possible — with a focus on precision. Abstract interpretation translates the program semantics into abstract semantics...... problems as the other by a reformulation. This thesis argues that there is even a convergence on the practical level, and that a generalisation of the formalism of timed automata into lattice automata captures key aspects of both methods; indeed model checking timed automata can be formulated in terms...... 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...
Model checking of component connectors
Izadi, Mohammad
2011-01-01
We present a framework for automata theoretic model checking of coordination systems specified in Reo coordination language. To this goal, we introduce Buchi automata of records (BAR) and their augmented version (ABAR) as an operational modeling formalism that covers several intended forms of behavi
基于Verics的组合Web服务有界模型检测%Bounded Model Checking Web Services Composition via Verics
Institute of Scientific and Technical Information of China (English)
骆翔宇; 轩爱成; 沙宗鲁
2011-01-01
传统的模型检测技术无法描述系统的认知逻辑特性,而在分布式系统领域,系统和协议的规范适合用多智能体时态认知逻辑来描述.组合Web服务是典型的分布式系统.为了保证组合Web服务运行的正确性,把组合Web服务看成多智能体系统,将其建模成一组相互通信的时间自动机.采用时态认知逻辑模型检测工具Verics对该组合Web服务的可用性、可靠性和时效性的时态认知逻辑特性进行检测.本文以旅游预订系统组合Web服务为例,阐述了上述过程.%The traditional model checking techniques can not describe the epistemic logic for systems. However, for distributed systems , the multi-agent temporal epistemic logics are suitable to express the desired properties of systems and protocols. The Web services composition is a typical kind of distributed systems. In order to guarantee the correctness of Web services, we first regard a Web services composition as a multi-agent system and translate the system description into a network of timed automata. We then apply Verics, a model checker for timed and multi-agent systems, to the verification of the usability, reliability and time-efficiency of Web services compositions, via temporal epistemic logic. To illustrate the effectiveness of the proposed method, we model a particular case study of a travel reservation system and check the related properties.
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.
Model Checking Linearizability via Refinement
Liu, Yang; Chen, Wei; Liu, Yanhong A.; Sun, Jun
Linearizability is an important correctness criterion for implementations of concurrent objects. Automatic checking of linearizability is challenging because it requires checking that 1) all executions of concurrent operations be serializable, and 2) the serialized executions be correct with respect to the sequential semantics. This paper describes a new method to automatically check linearizability based on refinement relations from abstract specifications to concrete implementations. Our method avoids the often difficult task of determining linearization points in implementations, but can also take advantage of linearization points if they are given. The method exploits model checking of finite state systems specified as concurrent processes with shared variables. Partial order reduction is used to effectively reduce the search space. The approach is built into a toolset that supports a rich set of concurrent operators. The tool has been used to automatically check a variety of implementations of concurrent objects, including the first algorithms for the mailbox problem and scalable NonZero indicators. Our system was able to find all known and injected bugs in these implementations.
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
Directory of Open Access Journals (Sweden)
Thomas J. STOHLGREN, Catherine S. JARNEVICH, Wayne E. ESAIAS,Jeffrey T. MORISETTE
2011-10-01
Full Text Available 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].
Timing analysis by model checking
Naydich, Dimitri; Guaspari, David
2000-01-01
The safety of modern avionics relies on high integrity software that can be verified to meet hard real-time requirements. The limits of verification technology therefore determine acceptable engineering practice. To simplify verification problems, safety-critical systems are commonly implemented under the severe constraints of a cyclic executive, which make design an expensive trial-and-error process highly intolerant of change. Important advances in analysis techniques, such as rate monotonic analysis (RMA), have provided a theoretical and practical basis for easing these onerous restrictions. But RMA and its kindred have two limitations: they apply only to verifying the requirement of schedulability (that tasks meet their deadlines) and they cannot be applied to many common programming paradigms. We address both these limitations by applying model checking, a technique with successful industrial applications in hardware design. Model checking algorithms analyze finite state machines, either by explicit state enumeration or by symbolic manipulation. Since quantitative timing properties involve a potentially unbounded state variable (a clock), our first problem is to construct a finite approximation that is conservative for the properties being analyzed-if the approximation satisfies the properties of interest, so does the infinite model. To reduce the potential for state space explosion we must further optimize this finite model. Experiments with some simple optimizations have yielded a hundred-fold efficiency improvement over published techniques.
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].
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
C/C ++program memory leak detection based on bounded model checking%基于有界模型检测的C/C＋＋程序内存泄露检测
Institute of Scientific and Technical Information of China (English)
黄蔚; 洪玫; 杨秋辉; 郭鑫宇; 代声馨; 徐保平; 高婉玲; 赵鹤
2016-01-01
The dynamic memory management mechanism in C /C ++programming language is free and flexible,but when used by developer it is easy to introduce memory leaks which lead to performance degradation and even failure of system.In order to detect memory leak more effectively,this paper proposed a memory leak detection method based on bounded model checking for C program called MLD-CBMC.It took C /C ++program files as input,unwound the program and inserted memory leak proper-ties,encoded the program constraints and properties into verification conditions using satisfiability modulo theory,then passed the verification conditions to a SMT solver.Thus it converted detecting memory leaks to solving satisfiability problems.By ex-periment and cooperation with other bounded model checking tools,MLD-CBMC shows its feasibility and effectiveness.%C ／C ＋＋语言中的动态内存管理机制自由且灵活，但动态内存的使用容易引入内存泄露，导致系统性能降低甚至系统崩溃。为了更加有效地检测内存泄露，提出了一个基于有界模型检测技术的 C ／C ＋＋程序内存泄露检测方案 MLD-CBMC。该方案以 C ／C ＋＋程序文件为输入，利用有界模型检测技术对程序进行展开处理，加入内存泄露性质，并利用可满足性模理论（SMT）对程序约束和性质组成的验证条件编码，使用 SMT 求解器对验证条件求解，将检测内存泄露问题转换为求解可满足性问题，实现 C ／C ＋＋程序内存泄露的检测。通过实验验证了方案的有效性，并与其他有界模型检测工具进行对比实验，实验证明方案对内存泄露的检测能力更强。
Model Checking Timed Automata with Priorities using DBM Subtraction
DEFF Research Database (Denmark)
David, Alexandre; Larsen, Kim Guldstrand; Pettersson, Paul;
2006-01-01
In this paper we describe an extension of timed automata with priorities, and efficient algorithms to compute subtraction on DBMs (difference bounded matrices), needed in symbolic model-checking of timed automata with priorities. The subtraction is one of the few operations on DBMs that result in...
Institute of Scientific and Technical Information of China (English)
骆翔宇; 苏开乐; 杨晋吉
2006-01-01
提出在同步的多智体系统中验证时态认知逻辑的有界模型检测(bounded model checking,简称BMC)算法.基于同步解释系统语义,在时态逻辑CTL*的语言中引入认知模态词,从而得到一个新的时态认知逻辑ECKLn.通过引入状态位置函数的方法获得同步系统的智能体知识,避免了为时间域而扩展通常的时态认知模型的状态及迁移关系编码.ECKLn的时态认知表达能力强于另一个逻辑CTLK.给出该算法的技术细节及正确性证明,并用火车控制系统实例解释算法的执行过程.
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...... and implementing abstractions will improve the applicability of model checking in practice....
Model Checking of Boolean Process Models
Schneider, Christoph
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 model explicitly states with a subsequent skipping of activations and arbitrary logical rules of type AND, XOR, OR etc. to model the split and join of the control flow. We apply model checking as a verification method for the safeness and liveness of Boolean systems. Model checking of Boolean systems uses the elementary theory of propositional logic, no modal operators are needed. Our verification builds on a finite complete prefix of a certain T-system attached to the Boolean system. It splits the processes of the Boolean sy...
Model Checking Software Systems: A Case Study.
1995-03-10
gained. We suggest a radically different tack: model checking. The two formal objects compared are a finite state machine model of the software...simply terminates. 3.1.1. State Machine Model Let’s consider a simplified model with just one client, one server, and one file. The top graph
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 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
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.
Posterior Predictive Model Checking in Bayesian Networks
Crawford, Aaron
2014-01-01
This simulation study compared the utility of various discrepancy measures within a posterior predictive model checking (PPMC) framework for detecting different types of data-model misfit in multidimensional Bayesian network (BN) models. The investigated conditions were motivated by an applied research program utilizing an operational complex…
A Method for Model Checking Feature Interactions
DEFF Research Database (Denmark)
Pedersen, Thomas; Le Guilly, Thibaut; Ravn, Anders Peter;
2015-01-01
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 ...... the definitions with models to ensure that all interactions are captured. The method is illustrated on a home automation example with model checking as analysis tool. In particular, the modelling formalism is timed automata and the analysis uses UPPAAL to find interactions....
Model checking coalitional games in shortage resource scenarios
Directory of Open Access Journals (Sweden)
Dario Della Monica
2013-07-01
Full Text Available Verification of multi-agents systems (MAS has been recently studied taking into account the need of expressing resource bounds. Several logics for specifying properties of MAS have been presented in quite a variety of scenarios with bounded resources. In this paper, we study a different formalism, called Priced Resource-Bounded Alternating-time Temporal Logic (PRBATL, whose main novelty consists in moving the notion of resources from a syntactic level (part of the formula to a semantic one (part of the model. This allows us to track the evolution of the resource availability along the computations and provides us with a formalisms capable to model a number of real-world scenarios. Two relevant aspects are the notion of global availability of the resources on the market, that are shared by the agents, and the notion of price of resources, depending on their availability. In a previous work of ours, an initial step towards this new formalism was introduced, along with an EXPTIME algorithm for the model checking problem. In this paper we better analyze the features of the proposed formalism, also in comparison with previous approaches. The main technical contribution is the proof of the EXPTIME-hardness of the the model checking problem for PRBATL, based on a reduction from the acceptance problem for Linearly-Bounded Alternating Turing Machines. In particular, since the problem has multiple parameters, we show two fixed-parameter reductions.
Model checking Quasi Birth Death processes
Remke, A.K.I.
2004-01-01
Quasi-Birth Death processes (QBDs) are a special class of infinite state CTMCs that combines a large degree of modeling expressiveness with efficient solution methods. This work adapts the well-known stochastic logic CSL for use on QBDs as CSL and presents model checking algorithms for so-called lev
Statistical Model Checking for Stochastic Hybrid Systems
DEFF Research Database (Denmark)
David, Alexandre; Du, Dehui; Larsen, Kim Guldstrand
2012-01-01
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 ap...
A Game-Based Approach for PCTL* Stochastic Model Checking with Evidence
Institute of Scientific and Technical Information of China (English)
Yang Liu; Xuan-Dong Li; Yan Ma
2016-01-01
Stochastic model checking is a recent extension and generalization of the classical model checking, which focuses on quantitatively checking the temporal property of a system model. PCTL* is one of the important quantitative property specification languages, which is strictly more expressive than either PCTL (probabilistic computation tree logic) or LTL (linear temporal logic) with probability bounds. At present, PCTL* stochastic model checking algorithm is very complicated, and cannot provide any relevant explanation of why a formula does or does not hold in a given model. For dealing with this problem, an intuitive and succinct approach for PCTL* stochastic model checking with evidence is put forward in this paper, which includes: presenting the game semantics for PCTL* in release-PNF (release-positive normal form), defining the PCTL*stochastic model checking game, using strategy solving in game to achieve the PCTL*stochastic model checking, and refining winning strategy as the evidence to certify stochastic model checking result. The soundness and the completeness of game-based PCTL* stochastic model checking are proved, and its complexity matches the known lower and upper bounds. The game-based PCTL*stochastic model checking algorithm is implemented in a visual prototype tool, and its feasibility is demonstrated by an illustrative example.
Using Stochastic Model Checking to Provision Complex Business Services
DEFF Research Database (Denmark)
Herbert, Luke Thomas; Sharp, Robin
2012-01-01
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......-deterministic branching and reward annotations. We then develop an algorithm for the efficient translation of these models into the guarded command language used by the model checker PRISM, in turn enabling model checking of BPMN processes and allowing for the calculation of a wide range of quantitative properties...
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...
Model Checking as Static Analysis: Revisited
DEFF Research Database (Denmark)
Zhang, Fuyuan; Nielson, Flemming; Nielson, Hanne Riis
2012-01-01
We show that the model checking problem of the μ-calculus can be viewed as an instance of static analysis. We propose Succinct Fixed Point Logic (SFP) within our logical approach to static analysis as an extension of Alternation-free Least Fixed Logic (ALFP). We generalize the notion...
Efficient CSL Model Checking Using Stratification
DEFF Research Database (Denmark)
Zhang, Lijun; Jansen, David N.; Nielson, Flemming;
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 expone...
Automata-Based CSL Model Checking
DEFF Research Database (Denmark)
Zhang, Lijun; Jansen, David N.; Nielson, Flemming;
2011-01-01
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. The presented decision procedure, however, has exponential complexity. In this paper, we...
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 t...
Software Model Checking for Verifying Distributed Algorithms
2014-10-28
Verification procedure is an intelligent exhaustive search of the state space of the design Model Checking 6 Verifying Synchronous Distributed App...Distributed App Sagar Chaki, June 11, 2014 © 2014 Carnegie Mellon University Tool Usage Project webpage (http://mcda.googlecode.com) • Tutorial
Model checking the HAVi leader election protocol
Romijn, J.M.T.
1999-01-01
The HAVi specification proposes an architecture for audio/video interoperability in home networks. Part of the HAVi specification is a distributed leader election protocol. We have modelled this leader election protocol in Promela and Lotos and have checked several properties with the tools Spin a
Model Checking the Remote Agent Planner
Khatib, Lina; Muscettola, Nicola; Havelund, Klaus; Norvig, Peter (Technical Monitor)
2001-01-01
This work tackles the problem of using Model Checking for the purpose of verifying the HSTS (Scheduling Testbed System) planning system. HSTS is the planner and scheduler of the remote agent autonomous control system deployed in Deep Space One (DS1). Model Checking allows for the verification of domain models as well as planning entries. We have chosen the real-time model checker UPPAAL for this work. We start by motivating our work in the introduction. Then we give a brief description of HSTS and UPPAAL. After that, we give a sketch for the mapping of HSTS models into UPPAAL and we present samples of plan model properties one may want to verify.
Model Checking with Probabilistic Tabled Logic Programming
Gorlin, Andrey; Smolka, Scott A
2012-01-01
We present a formulation of the problem of probabilistic model checking as one of query evaluation over probabilistic logic programs. To the best of our knowledge, our formulation is the first of its kind, and it covers a rich class of probabilistic models and probabilistic temporal logics. The inference algorithms of existing probabilistic logic-programming systems are well defined only for queries with a finite number of explanations. This restriction prohibits the encoding of probabilistic model checkers, where explanations correspond to executions of the system being model checked. To overcome this restriction, we propose a more general inference algorithm that uses finite generative structures (similar to automata) to represent families of explanations. The inference algorithm computes the probability of a possibly infinite set of explanations directly from the finite generative structure. We have implemented our inference algorithm in XSB Prolog, and use this implementation to encode probabilistic model...
Model checking the HAVi leader election protocol
Romijn, J.M.T.
1999-01-01
The HAVi specification proposes an architecture for audio/video interoperability in home networks. Part of the HAVi specification is a distributed leader election protocol. We have modelled this leader election protocol in Promela and Lotos and have checked several properties with the tools Spin and Xtl (from the Caesar/Aldebaran package). It turns out that the protocol does not meet some safety properties and that there are situations in which the protocol may never converge to designate a l...
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...
Statistical Model Checking of Rich Models and Properties
DEFF Research Database (Denmark)
Poulsen, Danny Bøgsted
in 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......Software is in increasing fashion embedded within safety- and business critical processes of society. Errors in these embedded systems can lead to human casualties or severe monetary loss. Model checking technology has proven formal methods capable of finding and correcting errors in software....... However, software is approaching the boundary in terms of the complexity and size that model checking can handle. Furthermore, software systems are nowadays more frequently interacting with their environment hence accurately modelling such systems requires modelling the environment as well - resulting...
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.
Automated Environment Generation for Software Model Checking
Tkachuk, Oksana; Dwyer, Matthew B.; Pasareanu, Corina S.
2003-01-01
A key problem in model checking open systems is environment modeling (i.e., representing the behavior of the execution context of the system under analysis). Software systems are fundamentally open since their behavior is dependent on patterns of invocation of system components and values defined outside the system but referenced within the system. Whether reasoning about the behavior of whole programs or about program components, an abstract model of the environment can be essential in enabling sufficiently precise yet tractable verification. In this paper, we describe an approach to generating environments of Java program fragments. This approach integrates formally specified assumptions about environment behavior with sound abstractions of environment implementations to form a model of the environment. The approach is implemented in the Bandera Environment Generator (BEG) which we describe along with our experience using BEG to reason about properties of several non-trivial concurrent Java programs.
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.
Statistical Model Checking for Product Lines
DEFF Research Database (Denmark)
ter Beek, Maurice H.; Legay, Axel; Lluch Lafuente, Alberto
2016-01-01
average cost of products (in terms of the attributes of the products’ features) and the probability of features to be (un)installed at runtime. The product lines must be modelled in QFLan, which extends the probabilistic feature-oriented language PFLan with novel quantitative constraints among features......We report on the suitability of statistical model checking for the analysis of quantitative properties of product line models by an extended treatment of earlier work by the authors. The type of analysis that can be performed includes the likelihood of specific product behaviour, the expected...... and on behaviour and with advanced feature installation options. QFLan is a rich process-algebraic specification language whose operational behaviour interacts with a store of constraints, neatly separating product configuration from product behaviour. The resulting probabilistic configurations and probabilistic...
Abstraction and Model Checking in the PEPA Plug-in for Eclipse
DEFF Research Database (Denmark)
Smith, Michael James Andrew
2010-01-01
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...
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...
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 ...
Model-Checking with Edge-Valued Decision Diagrams
Roux, Pierre; Siminiceanu, Radu I.
2010-01-01
We describe an algebra of Edge-Valued Decision Diagrams (EVMDDs) to encode arithmetic functions and its implementation in a model checking library along with state-of-the-art algorithms for building the transition relation and the state space of discrete state systems. We provide efficient algorithms for manipulating EVMDDs and give upper bounds of the theoretical time complexity of these algorithms for all basic arithmetic and relational operators. We also demonstrate that the time complexity of the generic recursive algorithm for applying a binary operator on EVMDDs is no worse than that of Multi-Terminal Decision Diagrams. We have implemented a new symbolic model checker with the intention to represent in one formalism the best techniques available at the moment across a spectrum of existing tools: EVMDDs for encoding arithmetic expressions, identity-reduced MDDs for representing the transition relation, and the saturation algorithm for reachability analysis. We compare our new symbolic model checking EVMDD library with the widely used CUDD package and show that, in many cases, our tool is several orders of magnitude faster than CUDD.
Analyzing Mode Confusion via Model Checking
Luettgen, Gerald; Carreno, Victor
1999-01-01
Mode confusion is one of the most serious problems in aviation safety. Today's complex digital flight decks make it difficult for pilots to maintain awareness of the actual states, or modes, of the flight deck automation. NASA Langley leads an initiative to explore how formal techniques can be used to discover possible sources of mode confusion. As part of this initiative, a flight guidance system was previously specified as a finite Mealy automaton, and the theorem prover PVS was used to reason about it. The objective of the present paper is to investigate whether state-exploration techniques, especially model checking, are better able to achieve this task than theorem proving and also to compare several verification tools for the specific application. The flight guidance system is modeled and analyzed in Murphi, SMV, and Spin. The tools are compared regarding their system description language, their practicality for analyzing mode confusion, and their capabilities for error tracing and for animating diagnostic information. It turns out that their strengths are complementary.
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.
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
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...
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.
Quantitative Safety: Linking Proof-Based Verification with Model Checking for Probabilistic Systems
Ndukwu, Ukachukwu
2009-01-01
This paper presents a novel approach for augmenting proof-based verification with performance-style analysis of the kind employed in state-of-the-art model checking tools for probabilistic systems. Quantitative safety properties usually specified as probabilistic system invariants and modeled in proof-based environments are evaluated using bounded model checking techniques. Our specific contributions include the statement of a theorem that is central to model checking safety properties of proof-based systems, the establishment of a procedure; and its full implementation in a prototype system (YAGA) which readily transforms a probabilistic model specified in a proof-based environment to its equivalent verifiable PRISM model equipped with reward structures. The reward structures capture the exact interpretation of the probabilistic invariants and can reveal succinct information about the model during experimental investigations. Finally, we demonstrate the novelty of the technique on a probabilistic library cas...
Optimisation of BPMN Business Models via Model Checking
DEFF Research Database (Denmark)
Herbert, Luke Thomas; Sharp, Robin
2013-01-01
We present a framework for the optimisation of business processes modelled in the business process modelling language BPMN, which builds upon earlier work, where we developed a model checking based method for the analysis of BPMN models. We define a structure for expressing optimisation goals...... for 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...
Modelling Chinese Smart Grid: A Stochastic Model Checking Case Study
Yüksel, Ender; Nielson, Flemming; Zhu, Huibiao; Huang, Heqing
2012-01-01
Cyber-physical systems integrate information and communication technology functions to the physical elements of a system for monitoring and controlling purposes. The conversion of traditional power grid into a smart grid, a fundamental example of a cyber-physical system, raises a number of issues that require novel methods and applications. In this context, an important issue is the verification of certain quantitative properties of the system. In this technical report, 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.
Model checking biological systems described using ambient calculus
DEFF Research Database (Denmark)
Mardare, Radu Iulian; Priami, Corrado; Qualia, Paola;
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....
Cross-entropy optimisation of importance sampling parameters for statistical model checking
Jégourel, Cyrille; Sedwards, Sean
2012-01-01
Statistical model checking avoids the exponential growth of states associated with probabilistic model checking by estimating properties from multiple executions of a system and by giving results within confidence bounds. Rare properties are often very important but pose a particular challenge for simulation-based approaches, hence a key objective under these circumstances is to reduce the number and length of simulations necessary to produce a given level of confidence. Importance sampling is a well-established technique that achieves this, however to maintain the advantages of statistical model checking it is necessary to find good importance sampling distributions without considering the entire state space. Motivated by the above, we present a simple algorithm that uses the notion of cross-entropy to find the optimal parameters for an importance sampling distribution. In contrast to previous work, our algorithm uses a low dimensional vector of parameters to define this distribution and thus avoids the ofte...
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.
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...
Scalable Capacity Bounding Models for Wireless Networks
Du, Jinfeng; Medard, Muriel; Xiao, Ming; Skoglund, Mikael
2014-01-01
The framework of network equivalence theory developed by Koetter et al. introduces a notion of channel emulation to construct noiseless networks as upper (resp. lower) bounding models, which can be used to calculate the outer (resp. inner) bounds for the capacity region of the original noisy network. Based on the network equivalence framework, this paper presents scalable upper and lower bounding models for wireless networks with potentially many nodes. A channel decoupling method is proposed...
Extending Model Checking to Object Process Validation
Rein, van H.
2002-01-01
Object-oriented techniques allow the gathering and modelling of system requirements in terms of an application area. The expression of data and process models at that level is a great asset in communication with non-technical people in that area, but it does not necessarily lead to consistent 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...
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
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 che...
Workflow Fault Tree Generation Through Model Checking
DEFF Research Database (Denmark)
Herbert, Luke Thomas; Sharp, Robin
2014-01-01
We present a framework for the automated generation of fault trees from models of realworld process workflows, expressed in a formalised subset of the popular Business Process Modelling and Notation (BPMN) language. To capture uncertainty and unreliability in workflows, we extend this formalism...
Generalization error bounds for stationary autoregressive models
McDonald, Daniel J; Schervish, Mark
2011-01-01
We derive generalization error bounds for stationary univariate autoregressive (AR) models. We show that the stationarity assumption alone lets us treat the estimation of AR models as a regularized kernel regression without the need to further regularize the model arbitrarily. We thereby bound the Rademacher complexity of AR models and apply existing Rademacher complexity results to characterize the predictive risk of AR models. We demonstrate our methods by predicting interest rate movements.
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...... to obtain some guarantee on the (un)schedulability of the model even in the presence of undecidability. Two methods are considered: symbolic model checking and statistical model checking. Since the model uses stop-watches, the reachability problem becomes undecidable so we are using an over......-approximation technique. We can safely conclude that the system is schedulable for varying values of BCET. For the cases where deadlines are violated, we use polyhedra to try to confirm the witnesses. Our alternative method to confirm non-schedulability uses statistical model-checking (SMC) to generate counter...
Multi-core and/or symbolic model checking
Dijk, van Tom; Laarman, Alfons; Pol, van de Jaco; Luettgen, G.; Merz, S.
2012-01-01
We review our progress in high-performance model checking. Our multi-core model checker is based on a scalable hash-table design and parallel random-walk traversal. Our symbolic model checker is based on Multiway Decision Diagrams and the saturation strategy. The LTSmin tool is based on the PINS arc
Symmetry and partial order reduction techniques in model checking Rebeca
Jaghouri, M.M.; Sirjani, M.; Mousavi, M.R.; Movaghar, A.
2007-01-01
Rebeca is an actor-based language with formal semantics that can be used in modeling concurrent and distributed software and protocols. In this paper, we study the application of partial order and symmetry reduction techniques to model checking dynamic Rebeca models. Finding symmetry based equivalen
Checking Flavour Models at Neutrino Facilities
Meloni, Davide
2013-01-01
In the recent years, the industry of model building has been the subject of the intense activity, especially after the measurement of a relatively large values of the reactor angle. Special attention has been devoted to the use of non-abelian discrete symmetries, thanks to their ability of reproducing some of the relevant features of the neutrino mixing matrix. In this paper, we consider two special relations between the leptonic mixing angles, arising from models based on S4 and A4, and study whether, and to which extent, they can be distinguished at superbeam facilities, namely T2K, NOvA and T2HK.
Checking flavour models at neutrino facilities
Energy Technology Data Exchange (ETDEWEB)
Meloni, Davide, E-mail: meloni@fis.uniroma3.it
2014-01-20
In the recent years, the industry of model building has been the subject of the intense activity, especially after the measurement of a relatively large values of the reactor angle. Special attention has been devoted to the use of non-abelian discrete symmetries, thanks to their ability of reproducing some of the relevant features of the neutrino mixing matrix. In this Letter, we consider two special relations between the leptonic mixing angles, arising from models based on S{sub 4} and A{sub 4}, and study whether, and to which extent, they can be distinguished at superbeam facilities, namely T2K, NOνA and T2HK.
CheckMATE 2: From the model to the limit
Dercks, Daniel; Kim, Jong Soo; Rolbiecki, Krzysztof; Tattersall, Jamie; Weber, Torsten
2016-01-01
We present the latest developments to the CheckMATE program that allows models of new physics to be easily tested against the recent LHC data. To achieve this goal, the core of CheckMATE now contains over 60 LHC analyses of which 12 are from the 13 TeV run. The main new feature is that CheckMATE 2 now integrates the Monte Carlo event generation via Madgraph and Pythia 8. This allows users to go directly from a SLHA file or UFO model to the result of whether a model is allowed or not. In addition, the integration of the event generation leads to a significant increase in the speed of the program. Many other improvements have also been made, including the possibility to now combine signal regions to give a total likelihood for a model.
Model Checking Event-B by Encoding into Alloy
Matos, Paulo J
2008-01-01
As systems become ever more complex, verification becomes more main stream. Event-B and Alloy are two formal specification languages based on fairly different methodologies. While Event-B uses theorem provers to prove that invariants hold for a given specification, Alloy uses a SAT-based model finder. In some settings, Event-B invariants may not be proved automatically, and so the often difficult step of interactive proof is required. One solution for this problem is to validate invariants with model checking. This work studies the encoding of Event-B machines and contexts to Alloy in order to perform temporal model checking with Alloy's SAT-based engine.
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.
Universality: Accurate Checks in Dyson's Hierarchical Model
Godina, J. J.; Meurice, Y.; Oktay, M. B.
2003-06-01
In this talk we present high-accuracy calculations of the susceptibility near βc for Dyson's hierarchical model in D = 3. Using linear fitting, we estimate the leading (γ) and subleading (Δ) exponents. Independent estimates are obtained by calculating the first two eigenvalues of the linearized renormalization group transformation. We found γ = 1.29914073 ± 10 -8 and, Δ = 0.4259469 ± 10-7 independently of the choice of local integration measure (Ising or Landau-Ginzburg). After a suitable rescaling, the approximate fixed points for a large class of local measure coincide accurately with a fixed point constructed by Koch and Wittwer.
Distributed Maximality based CTL Model Checking
Directory of Open Access Journals (Sweden)
Djamel Eddine Saidouni
2010-05-01
Full Text Available In this paper we investigate an approach to perform a distributed CTL Model checker algorithm on a network of workstations using Kleen three value logic, the state spaces is partitioned among the network nodes, We represent the incomplete state spaces as a Maximality labeled Transition System MLTS which are able to express true concurrency. we execute in parallel the same algorithm in each node, for a certain property on an incomplete MLTS , this last compute the set of states which satisfy or which if they fail are assigned the value .The third value mean unknown whether true or false because the partial state space lacks sufficient information needed for a precise answer concerning the complete state space .To solve this problem each node exchange the information needed to conclude the result about the complete state space. The experimental version of the algorithm is currently being implemented using the functional programming language Erlang.
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.
Using Model Checking for Analyzing Distributed Power Control Problems
DEFF Research Database (Denmark)
Brihaye, Thomas; Jungers, Marc; Lasaulce, Samson
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...
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.
Precise and Efficient Static Array Bound Checking for Large Embedded C Programs
Venet, Arnaud
2004-01-01
In this paper we describe the design and implementation of a static array-bound checker for a family of embedded programs: the flight control software of recent Mars missions. These codes are large (up to 250 KLOC), pointer intensive, heavily multithreaded and written in an object-oriented style, which makes their analysis very challenging. We designed a tool called C Global Surveyor (CGS) that can analyze the largest code in a couple of hours with a precision of 80%. The scalability and precision of the analyzer are achieved by using an incremental framework in which a pointer analysis and a numerical analysis of array indices mutually refine each other. CGS has been designed so that it can distribute the analysis over several processors in a cluster of machines. To the best of our knowledge this is the first distributed implementation of static analysis algorithms. Throughout the paper we will discuss the scalability setbacks that we encountered during the construction of the tool and their impact on the initial design decisions.
Model checking conditional CSL for continuous-time Markov chains
DEFF Research Database (Denmark)
Gao, Yang; Xu, Ming; Zhan, Naijun;
2013-01-01
In this paper, we consider the model-checking problem of continuous-time Markov chains (CTMCs) with respect to conditional logic. To the end, we extend Continuous Stochastic Logic introduced in Aziz et al. (2000) [1] to Conditional Continuous Stochastic Logic (CCSL) by introducing a conditional...
Lessons Learned Model Checking an Industrial Communications Library
2005-09-01
Lecture Notes in Computer Science [LNCS], volume 2057). Toronto, Canada, May 19-20, 2001. Berlin...Model Checking,” 128-147. Integrated Formal Methods: The 4th International Conference (IFM 2004) ( Lecture Notes in Computer Science [LNCS], volume...on Computer Aided Verification (CAV 1990). ( Lecture Notes in Computer Science [LNCS], volume 531). New Brunswick, NJ, June 18-21, 1990.
Model checking abstract state machines with answer set programming
2006-01-01
Answer Set Programming (ASP) is a logic programming paradigm that has been shown as a useful tool in various application areas due to its expressive modelling language. These application areas include Bourided Model Checking (BMC). BMC is a verification technique that is recognized for its strong ability of finding errors in computer systems. To apply BMC, a system needs to be modelled in a formal specification language, such as the widely used formalism of Abstract State Machines (ASMs). In ...
Efficient family-based model checking via variability abstractions
DEFF Research Database (Denmark)
Dimovski, Aleksandar; Al-Sibahi, Ahmad Salim; Brabrand, Claus
2016-01-01
variational models using the standard version of (single-system) Spin. The variability abstractions are first defined as Galois connections on semantic domains. We then show how to use them for defining abstract family-based model checking, where a variability model is replaced with an abstract version of it......Many software systems are variational: they can be configured to meet diverse sets of requirements. They can produce a (potentially huge) number of related systems, known as products or variants, by systematically reusing common parts. For variational models (variational systems or families...... of related systems), specialized family-based model checking algorithms allow efficient verification of multiple variants, simultaneously, in a single run. These algorithms, implemented in a tool Snip, scale much better than ``the brute force'' approach, where all individual systems are verified using...
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.
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
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...
Probabilistic Priority Message Checking Modeling Based on Controller Area Networks
Lin, Cheng-Min
Although the probabilistic model checking tool called PRISM has been applied in many communication systems, such as wireless local area network, Bluetooth, and ZigBee, the technique is not used in a controller area network (CAN). In this paper, we use PRISM to model the mechanism of priority messages for CAN because the mechanism has allowed CAN to become the leader in serial communication for automobile and industry control. Through modeling CAN, it is easy to analyze the characteristic of CAN for further improving the security and efficiency of automobiles. The Markov chain model helps us to model the behaviour of priority messages.
Bound States in Boson Impurity Models
Shi, Tao; Wu, Ying-Hai; González-Tudela, A.; Cirac, J. I.
2016-04-01
The formation of bound states involving multiple particles underlies many interesting quantum physical phenomena, such as Efimov physics or superconductivity. In this work, we show the existence of an infinite number of such states for some boson impurity models. They describe free bosons coupled to an impurity and include some of the most representative models in quantum optics. We also propose a family of wave functions to describe the bound states and verify that it accurately characterizes all parameter regimes by comparing its predictions with exact numerical calculations for a one-dimensional tight-binding Hamiltonian. For that model, we also analyze the nature of the bound states by studying the scaling relations of physical quantities, such as the ground-state energy and localization length, and find a nonanalytical behavior as a function of the coupling strength. Finally, we discuss how to test our theoretical predictions in experimental platforms, such as photonic crystal structures and cold atoms in optical lattices.
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...... in the classical formulation of ALFP logic. Finally, we show that the logics and the associated solvers can be used for rapid prototyping. We illustrate that by a variety of case studies from static analysis and model checking....... rapid prototyping of new analyses and consists of variants of ALFP logic and associated solvers. First, we present a Lattice based Least Fixed Point Logic (LLFP) that allows interpretations over complete lattices satisfying Ascending Chain Condition. We establish a Moore Family result for LLFP...
Model Checking Real-Time Value-Passing Systems
Institute of Scientific and Technical Information of China (English)
Jing Chen; Zio-Ning Cao
2004-01-01
In this paper,to model check real-time value-passing systems,a formal language Timed Symbolic Transition Graph and a logic system named Timed Predicate μ-Calculus are proposed.An algorithm is presented which is local in that it generates and investigates the reachable state space in top-down fashion and maintains the partition for time evaluations as coarse as possible while on-the-fly instantiating data variables.It can deal with not only data variables with finite value domain,but also the so called data independent variables with infinite value domain.To authors knowledge,this is the first algorithm for model checking timed systems containing value-passing features.
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.
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 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 with Multi-Threaded IC3 Portfolios
2015-01-15
Model Checking with Multi-Threaded IC3 Portfolios Sagar Chaki and Derrick Karimi Software Engineering Institute, Carnegie Mellon University {chaki...different runs varies randomly depending on the thread interleaving. The use of a portfolio of solvers to maximize the likelihood of a quick solution is...investigated. Using the Extreme Value theorem, the runtime of each variant, as well as their portfolios is analysed statistically. A formula for the
Approximating Attractors of Boolean Networks by Iterative CTL Model Checking.
Klarner, Hannes; Siebert, Heike
2015-01-01
This paper introduces the notion of approximating asynchronous attractors of Boolean networks by minimal trap spaces. We define three criteria for determining the quality of an approximation: "faithfulness" which requires that the oscillating variables of all attractors in a trap space correspond to their dimensions, "univocality" which requires that there is a unique attractor in each trap space, and "completeness" which requires that there are no attractors outside of a given set of trap spaces. Each is a reachability property for which we give equivalent model checking queries. Whereas faithfulness and univocality can be decided by model checking the corresponding subnetworks, the naive query for completeness must be evaluated on the full state space. Our main result is an alternative approach which is based on the iterative refinement of an initially poor approximation. The algorithm detects so-called autonomous sets in the interaction graph, variables that contain all their regulators, and considers their intersection and extension in order to perform model checking on the smallest possible state spaces. A benchmark, in which we apply the algorithm to 18 published Boolean networks, is given. In each case, the minimal trap spaces are faithful, univocal, and complete, which suggests that they are in general good approximations for the asymptotics of Boolean networks.
Introduction of Virtualization Technology to Multi-Process Model Checking
Leungwattanakit, Watcharin; Artho, Cyrille; Hagiya, Masami; Tanabe, Yoshinori; Yamamoto, Mitsuharu
2009-01-01
Model checkers find failures in software by exploring every possible execution schedule. Java PathFinder (JPF), a Java model checker, has been extended recently to cover networked applications by caching data transferred in a communication channel. A target process is executed by JPF, whereas its peer process runs on a regular virtual machine outside. However, non-deterministic target programs may produce different output data in each schedule, causing the cache to restart the peer process to handle the different set of data. Virtualization tools could help us restore previous states of peers, eliminating peer restart. This paper proposes the application of virtualization technology to networked model checking, concentrating on JPF.
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
in the specification of a 16 bit multiplier. As opposed to Bounded Model Checking (BMC) our method is complete in practice. Our technique is based on a quantification procedure that allows us to eliminate quantifiers in Quantified Boolean Formulas (QBF). The basic step of this procedure is the up-one operation...... for BEDs. In addition we list a number of important optimizations to reduce the number of basic steps. In particular the optimization rule of quantification-by-substitution turned out to be very useful: exists x : {g /\\ ( x f )} = g[f/x]. The rule is used (1) during fixed point iterations, (2) for deciding...
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.
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.
Optimizing ZigBee Security using Stochastic Model Checking
Yüksel, Ender; Nielson, Flemming; Fruth, Matthias; Kwiatkowska, Marta
2012-01-01
ZigBee is a fairly new but promising wireless sensor network standard that offers the advantages of simple and low resource communication. Nevertheless, security is of great concern to ZigBee, and enhancements are prescribed in the latest ZigBee specication: ZigBee-2007. In this technical report, we identify an important gap in the specification on key updates, and present a methodology for determining optimal key update policies and security parameters. We exploit the stochastic model checking approach using the probabilistic model checker PRISM, and assess the security needs for realistic application scenarios.
Model Checking Workflow Net Based on Petri Net
Institute of Scientific and Technical Information of China (English)
ZHOU Conghua; CHEN Zhenyu
2006-01-01
The soundness is a very important criterion for the correctness of the workflow.Specifying the soundness with Computation Tree Logic (CTL) allows us to verify the soundness with symbolic model checkers.Therefore the state explosion problem in verifying soundness can be overcome efficiently.When the property is not satisfied by the system,model checking can give a counter-example, which can guide us to correct the workflow.In addition, relaxed soundness is another important criterion for the workflow.We also prove that Computation Tree Logic * (CTL * ) can be used to character the relaxed soundness of the workflow.
Optimizing ZigBee Security using Stochastic Model Checking
DEFF Research Database (Denmark)
Yuksel, Ender; Nielson, Hanne Riis; Nielson, Flemming
ZigBee is a fairly new but promising wireless sensor network standard that offers the advantages of simple and low resource communication. Nevertheless, security is of great concern to ZigBee, and enhancements are prescribed in the latest ZigBee specication: ZigBee-2007. In this technical report......, we identify an important gap in the specification on key updates, and present a methodology for determining optimal key update policies and security parameters. We exploit the stochastic model checking approach using the probabilistic model checker PRISM, and assess the security needs for realistic...
Network segregation in a model of misinformation and fact checking
Tambuscio, Marcella; Ciampaglia, Giovanni Luca; Ruffo, Giancarlo
2016-01-01
Misinformation under the form of rumor, hoaxes, and conspiracy theories spreads on social media at alarming rates. One hypothesis is that, since social media are shaped by homophily, belief in misinformation may be more likely to thrive on those social circles that are segregated from the rest of the network. One possible antidote is fact checking which, in some cases, is known to stop rumors from spreading further. However, fact checking may also backfire and reinforce the belief in a hoax. Here we take into account the combination of network segregation, finite memory and attention, and fact-checking efforts. We consider a compartmental model of two interacting epidemic processes over a network that is segregated between gullible and skeptic users. Extensive simulation and mean-field analysis show that a more segregated network facilitates the spread of a hoax only at low forgetting rates, but has no effect when agents forget at faster rates. This finding may inform the development of mitigation techniques ...
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...
Efficient Parallel Statistical Model Checking of Biochemical Networks
Directory of Open Access Journals (Sweden)
Paolo Ballarini
2009-12-01
Full Text Available We consider the problem of verifying stochastic models of biochemical networks against behavioral properties expressed in temporal logic terms. Exact probabilistic verification approaches such as, for example, CSL/PCTL model checking, are undermined by a huge computational demand which rule them out for most real case studies. Less demanding approaches, such as statistical model checking, estimate the likelihood that a property is satisfied by sampling executions out of the stochastic model. We propose a methodology for efficiently estimating the likelihood that a LTL property P holds of a stochastic model of a biochemical network. As with other statistical verification techniques, the methodology we propose uses a stochastic simulation algorithm for generating execution samples, however there are three key aspects that improve the efficiency: first, the sample generation is driven by on-the-fly verification of P which results in optimal overall simulation time. Second, the confidence interval estimation for the probability of P to hold is based on an efficient variant of the Wilson method which ensures a faster convergence. Third, the whole methodology is designed according to a parallel fashion and a prototype software tool has been implemented that performs the sampling/verification process in parallel over an HPC architecture.
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.
Survey for Stochastic Model Checking%随机模型检验研究
Institute of Scientific and Technical Information of China (English)
刘阳; 李宣东; 马艳; 王林章
2015-01-01
随机模型检验作为模型检验理论的延伸和推广，可用于验证分析系统模型的定性或定量性质，其已经应用到随机分布式算法验证、通信协议性能分析甚至是系统生物学等跨学科领域。从20世纪90年代末至今，随机模型检验引起了形式验证等领域的广泛关注，并取得了很大的进展。该文追溯了随机模型检验的渊源，系统地概括了其最基本的原理及几类典型的 PCTL、概率的 LTL、PCTL*和 CSL 模型检验随机系统的算法框架。然后归纳总结了随机模型检验的主要研究方向及其进展，分析了基于随机模型检验的验证过程及其优势与劣势，并分类列出了目前出现的随机模型检验工具。最后介绍了随机模型检验的应用领域并指出了其未来的应用挑战。%Stochastic model checking is extension and generalization of the theory of model checking,which can verify and analyze system model quantitatively and qualitatively,and has been applied in the areas of verification of randomized distributed algorithms,performance analysis of communication protocols,and even the cross-disciplinary fields such as systems biology.Since the late 1990s,stochastic model checking has received widespread concern in the formal verification filed,and has made great progress.In this paper,we retrospect the origin of stochastic model checking,and discuss the basic principle of stochastic model checking systematically including the PCTL,LTL with probability bounds,PCTL* and CSL model checking algorithm.Then we summarize the main research direction and progress of stochastic model checking in recent years, analyze the verification process and advantages/disadvantages of stochastic model checking deeply, classify and list tools for stochastic model checking.Finally,we introduce the application areas of stochastic model checking and point out its future challenge.
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.
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...... 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....
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......In this paper we present two frameworks that have been implemented to link traditional model-checking techniques to the domain of control. The techniques are based on solving a timed game and using the resulting solution (a strategy) as a controller. The obtained discrete controller must fit within...... 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....
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.
Take it NP-easy: Bounded model construction for duration calculus
DEFF Research Database (Denmark)
Fränzle, Martin
2002-01-01
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...
Model Checking with Edge-Valued Decision Diagrams
Roux, Pierre; Siminiceanu, Radu I.
2010-01-01
We describe an algebra of Edge-Valued Decision Diagrams (EVMDDs) to encode arithmetic functions and its implementation in a model checking library. We provide efficient algorithms for manipulating EVMDDs and review the theoretical time complexity of these algorithms for all basic arithmetic and relational operators. We also demonstrate that the time complexity of the generic recursive algorithm for applying a binary operator on EVMDDs is no worse than that of Multi- Terminal Decision Diagrams. We have implemented a new symbolic model checker with the intention to represent in one formalism the best techniques available at the moment across a spectrum of existing tools. Compared to the CUDD package, our tool is several orders of magnitude faster
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.
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.
Verification of Quantum Cryptography Protocols by Model Checking
Directory of Open Access Journals (Sweden)
Mohamed Elboukhari
2010-10-01
Full Text Available Unlike classical cryptography which is based on mathematical functions, Quantum Cryptography orQuantum Key Distribution (QKD exploits the laws of quantum physics to offer unconditionally securecommunication. The progress of research in this field allows the anticipation of QKD to be availableoutside of laboratories within the next few years and efforts are made to improve the performance andreliability of the implemented technologies. But despite this big progress, several challenges remain. Forexample the task of how to test the devices of QKD did not yet receive enough attention. These apparatusesbecome heterogeneous, complex and so demand a big verification effort. In this paper we propose to studyquantum cryptography protocols by applying the technique of probabilistic model checking. Using PRISMtool, we analyze the security of BB84 protocol and we are focused on the specific security property ofeavesdropper's information gain on the key derived from the implementation of this protocol. We show thatthis property is affected by the parameters of the eavesdropper’s power and the quantum channel.
Model Checking Vector Addition Systems with one zero-test
Bonet, Rémi; Leroux, Jérôme; Zeitoun, Marc
2012-01-01
We design a variation of the Karp-Miller algorithm to compute, in a forward manner, a finite representation of the cover (i.e., the downward closure of the reachability set) of a vector addition system with one zero-test. This algorithm yields decision procedures for several problems for these systems, open until now, such as place-boundedness or LTL model-checking. The proof techniques to handle the zero-test are based on two new notions of cover: the refined and the filtered cover. The refined cover is a hybrid between the reachability set and the classical cover. It inherits properties of the reachability set: equality of two refined covers is undecidable, even for usual Vector Addition Systems (with no zero-test), but the refined cover of a Vector Addition System is a recursive set. The second notion of cover, called the filtered cover, is the central tool of our algorithms. It inherits properties of the classical cover, and in particular, one can effectively compute a finite representation of this set, e...
Multi-Objective Model Checking of Markov Decision Processes
Etessami, Kousha; Vardi, Moshe Y; Yannakakis, Mihalis
2008-01-01
We study and provide efficient algorithms for multi-objective model checking problems for Markov Decision Processes (MDPs). Given an MDP, $M$, and given multiple linear-time ($\\omega$-regular or LTL) properties $\\varphi_i$, and probabilities $r_i \\in [0,1]$, $i=1,...,k$, we ask whether there exists a strategy $\\sigma$ for the controller such that, for all $i$, the probability that a trajectory of $M$ controlled by $\\sigma$ satisfies $\\varphi_i$ is at least $r_i$. We provide an algorithm that decides whether there exists such a strategy and if so produces it, and which runs in time polynomial in the size of the MDP. Such a strategy may require the use of both randomization and memory. We also consider more general multi-objective $\\omega$-regular queries, which we motivate with an application to assume-guarantee compositional reasoning for probabilistic systems. Note that there can be trade-offs between different properties: satisfying property $\\varphi_1$ with high probability may necessitate satisfying $\\var...
Model Adequacy Checks for Discrete Choice Dynamic Models
Kheifets, Igor
2012-01-01
This paper proposes new parametric model adequacy tests for possibly nonlinear and nonstationary time series models with noncontinuous data distribution, which is often the case in applied work. In particular, we consider the correct specification of parametric conditional distributions in dynamic discrete choice models, not only of some particular conditional characteristics such as moments or symmetry. Knowing the true distribution is important in many circumstances, in particular to apply efficient maximum likelihood methods, obtain consistent estimates of partial effects and appropriate predictions of the probability of future events. We propose a transformation of data which under the true conditional distribution leads to continuous uniform iid series. The uniformity and serial independence of the new series is then examined simultaneously. The transformation can be considered as an extension of the integral transform tool for noncontinuous data. We derive asymptotic properties of such tests taking into...
The Model Checking Problem for Propositional Intuitionistic Logic with One Variable is AC1-Complete
Weiss, Martin Mundhenk And Felix
2010-01-01
We investigate the complexity of the model checking problem for propositional intuitionistic logic. We show that the model checking problem for intuitionistic logic with one variable is complete for logspace-uniform AC1, and for intuitionistic logic with two variables it is P-complete. For superintuitionistic logics with one variable, we obtain NC1-completeness for the model checking problem and for the tautology problem.
Model-checking mean-field models: algorithms & applications
Kolesnichenko, Anna Victorovna
2014-01-01
Large systems of interacting objects are highly prevalent in today's world. In this thesis we primarily address such large systems in computer science. We model such large systems using mean-field approximation, which allows to compute the limiting behaviour of an infinite population of identical o
Family-Based Model Checking Without a Family-Based Model Checker
DEFF Research Database (Denmark)
Dimovski, Aleksandar; Al-Sibahi, Ahmad Salim; Brabrand, Claus
2015-01-01
(systems with variability), specialized family-based model checking algorithms allow efficient verification of multiple variants, simultaneously. These algorithms scale much better than ``brute force'' verification of individual systems, one-by-one. Nevertheless, they can deal with only very small...... variational models. We address two key problems of family-based model checking. First, we improve scalability by introducing abstractions that simplify variability. Second, we reduce the burden of maintaining specialized family-based model checkers, by showing how the presented variability abstractions can...... be used to model-check variational models using the standard version of (single system) SPIN. The abstractions are first defined as Galois connections on semantic domains. We then show how to translate them into syntactic source-to-source transformations on variational models. This allows the use of SPIN...
Model building and model checking for biochemical processes.
Antoniotti, Marco; Policriti, Alberto; Ugel, Nadia; Mishra, Bud
2003-01-01
A central claim of computational systems biology is that, by drawing on mathematical approaches developed in the context of dynamic systems, kinetic analysis, computational theory and logic, it is possible to create powerful simulation, analysis, and reasoning tools for working biologists to decipher existing data, devise new experiments, and ultimately to understand functional properties of genomes, proteomes, cells, organs, and organisms. In this article, a novel computational tool is described that achieves many of the goals of this new discipline. The novelty of this system involves an automaton-based semantics of the temporal evolution of complex biochemical reactions starting from the representation given as a set of differential equations. The related tools also provide ability to qualitatively reason about the systems using a propositional temporal logic that can express an ordered sequence of events succinctly and unambiguously. The implementation of mathematical and computational models in the Simpathica and XSSYS systems is described briefly. Several example applications of these systems to cellular and biochemical processes are presented: the two most prominent are Leibler et al.'s repressilator (an artificial synthesized oscillatory network), and Curto- Voit-Sorribas-Cascante's purine metabolism reaction model.
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.
A lower bound on adiabatic heating of compressed turbulence for simulation and model validation
Davidovits, Seth
2016-01-01
The energy in turbulent flow can be amplified by compression, when the compression occurs on a timescale shorter than the turbulent dissipation time. This mechanism may play a part in sustaining turbulence in various astrophysical systems, including molecular clouds. The amount of turbulent amplification depends on the net effect of the compressive forcing and turbulent dissipation. By giving an argument for a bound on this dissipation, we give a lower bound for the scaling of the turbulent velocity with compression ratio in compressed turbulence. That is, turbulence undergoing compression will be enhanced at least as much as the bound given here, subject to a set of caveats that will be outlined. Used as a validation check, this lower bound suggests that some simulations and models of compressing astrophysical turbulence are too dissipative. The technique used highlights the relationship between compressed turbulence and decaying turbulence.
Modelling and Analysis of Smart Grid: A Stochastic Model Checking Case Study
DEFF Research Database (Denmark)
Yuksel, Ender; Zhu, Huibiao; Nielson, Hanne Riis
2012-01-01
Cyber-physical systems integrate information and communication technology functions to the physical elements of a system for monitoring and controlling purposes. The conversion of traditional power grid into a smart grid, a fundamental example of a cyber-physical system, raises a number of issues...... consumption. We employ stochastic model checking approach and present our modelling and analysis study using PRISM model checker....
Towards Symbolic Model-Based Mutation Testing: Combining Reachability and Refinement Checking
Aichernig, Bernhard K; 10.4204/EPTCS.80.7
2012-01-01
Model-based mutation testing uses altered test models to derive test cases that are able to reveal whether a modelled fault has been implemented. This requires conformance checking between the original and the mutated model. This paper presents an approach for symbolic conformance checking of action systems, which are well-suited to specify reactive systems. We also consider nondeterminism in our models. Hence, we do not check for equivalence, but for refinement. We encode the transition relation as well as the conformance relation as a constraint satisfaction problem and use a constraint solver in our reachability and refinement checking algorithms. Explicit conformance checking techniques often face state space explosion. First experimental evaluations show that our approach has potential to outperform explicit conformance checkers.
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.
Models and Techniques for Proving Data Structure Lower Bounds
DEFF Research Database (Denmark)
Larsen, Kasper Green
In this dissertation, we present a number of new techniques and tools for proving lower bounds on the operational time of data structures. These techniques provide new lines of attack for proving lower bounds in both the cell probe model, the group model, the pointer machine model and the I/O-mod...... for range reporting problems in the pointer machine and the I/O-model. With this technique, we tighten the gap between the known upper bound and lower bound for the most fundamental range reporting problem, orthogonal range reporting. 5......In this dissertation, we present a number of new techniques and tools for proving lower bounds on the operational time of data structures. These techniques provide new lines of attack for proving lower bounds in both the cell probe model, the group model, the pointer machine model and the I....../O-model. In all cases, we push the frontiers further by proving lower bounds higher than what could possibly be proved using previously known techniques. For the cell probe model, our results have the following consequences: The rst (lg n) query time lower bound for linear space static data structures...
Using Canonical Forms for Isomorphism Reduction in Graph-based Model Checking
Kant, Gijs
2010-01-01
Graph isomorphism checking can be used in graph-based model checking to achieve symmetry reduction. Instead of one-to-one comparing the graph representations of states, canonical forms of state graphs can be computed. These canonical forms can be used to store and compare states. However, computing
Quantitative modelling and analysis of a Chinese smart grid: a stochastic model checking case study
DEFF Research Database (Denmark)
Yuksel, Ender; Nielson, Hanne Riis; Nielson, Flemming
2014-01-01
Cyber-physical systems integrate information and communication technology with the physical elements of a system, mainly for monitoring and controlling purposes. The conversion of traditional power grid into a smart grid, a fundamental example of a cyber-physical system, raises a number of issues...... consumption.We employ stochastic model checking approach and present our modelling and analysis study using PRISM model checker....
Model Checking for a General Linear Model with Nonignorable Missing Covariates
Institute of Scientific and Technical Information of China (English)
Zhi-hua SUN; Wai-Cheung IP; Heung WONG
2012-01-01
In this paper,we investigate the model checking problem for a general linear model with nonignorable missing covariates.We show that,without any parametric model assumption for the response probability,the least squares method yields consistent estimators for the linear model even if only the complete data are applied.This makes it feasible to propose two testing procedures for the corresponding model checking problem:a score type lack-of-fit test and a test based on the empirical process.The asymptotic properties of the test statistics are investigated.Both tests are shown to have asymptotic power 1 for local alternatives converging to the null at the rate n-(r),0 ≤ (r) ＜ 1/2.Simulation results show that both tests perform satisfactorily.
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.
Model Independent Naturalness Bounds on Magnetic Moments of Majorana Neutrinos
Gorchtein, Mikhail; Bell, Nicole F.; Ramsey-Musolf, Michael J.; Vogel, Petr; Wang, Peng
2007-01-01
We analyze the implications of neutrino masses for the magnitude of neutrino magnetic moments. By considering electroweak radiative corrections to the neutrino mass, we derive model-independent naturalness upper bounds on neutrino magnetic moments, generated by physics above the electroweak scale. For Majorana neutrinos, these bounds are weaker than present experimental limits if $\\mu_\
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 e
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, ...
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 via...
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.
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.
Bounds for the chaotic region in the Lorenz model
Barrio, Roberto; Serrano, Sergio
2009-08-01
In a previous paper, the authors made an extensive numerical study of the Lorenz model, changing all three parameters of the system. We conjectured that the region of parameters where the Lorenz model is chaotic is bounded for fixed r. In this paper, we give a theoretical proof of the conjecture by obtaining theoretical bounds for the chaotic region and by using Fenichel theory. The theoretical bounds are complemented with numerical studies performed using the Maximum Lyapunov Exponent and OFLI2 techniques, and a comparison of both sets of results is shown. Finally, we provide a complete three-dimensional model of the chaotic regime depending on the three parameters.
Family-Based Model Checking Without a Family-Based Model Checker
DEFF Research Database (Denmark)
Dimovski, Aleksandar; Al-Sibahi, Ahmad Salim; Brabrand, Claus;
2015-01-01
be used to model-check variational models using the standard version of (single system) SPIN. The abstractions are first defined as Galois connections on semantic domains. We then show how to translate them into syntactic source-to-source transformations on variational models. This allows the use of SPIN...... with all its accumulated optimizations for efficient verification of variational models without any knowledge about variability. We demonstrate the practicality of this method on several examples using both the SNIP (family based) and SPIN (single system) model checkers....
New modeling approach for bounding flight in birds.
Sachs, Gottfried; Lenz, Jakob
2011-12-01
A new modeling approach is presented which accounts for the unsteady motion features and dynamics characteristics of bounding flight. For this purpose, a realistic mathematical model is developed to describe the flight dynamics of a bird with regard to a motion which comprises flapping and bound phases involving acceleration and deceleration as well as, simultaneously, pull-up and push-down maneuvers. Furthermore, a mathematical optimization method is used for determining that bounding flight mode which yields the minimum energy expenditure per range. Thus, it can be shown to what extent bounding flight is aerodynamically superior to continuous flapping flight, yielding a reduction in the energy expenditure in the speed range practically above the maximum range speed. Moreover, the role of the body lift for the efficiency of bounding flight is identified and quantified. Introducing an appropriate non-dimensionalization of the relations describing the bird's flight dynamics, results of generally valid nature are derived for the addressed items.
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.)
On Diagnostic Checking of Vector ARMA-GARCH Models with Gaussian and Student-t Innovations
Directory of Open Access Journals (Sweden)
Yongning Wang
2013-04-01
Full Text Available This paper focuses on the diagnostic checking of vector ARMA (VARMA models with multivariate GARCH errors. For a fitted VARMA-GARCH model with Gaussian or Student-t innovations, we derive the asymptotic distributions of autocorrelation matrices of the cross-product vector of standardized residuals. This is different from the traditional approach that employs only the squared series of standardized residuals. We then study two portmanteau statistics, called Q1(M and Q2(M, for model checking. A residual-based bootstrap method is provided and demonstrated as an effective way to approximate the diagnostic checking statistics. Simulations are used to compare the performance of the proposed statistics with other methods available in the literature. In addition, we also investigate the effect of GARCH shocks on checking a fitted VARMA model. Empirical sizes and powers of the proposed statistics are investigated and the results suggest a procedure of using jointly Q1(M and Q2(M in diagnostic checking. The bivariate time series of FTSE 100 and DAX index returns is used to illustrate the performance of the proposed portmanteau statistics. The results show that it is important to consider the cross-product series of standardized residuals and GARCH effects in model checking.
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.
Li, Tongyun; Xie, Chao; Jiao, Hong
2016-05-30
This article explored the application of the posterior predictive model checking (PPMC) method in assessing fit for unidimensional polytomous item response theory (IRT) models, specifically the divide-by-total models (e.g., the generalized partial credit model). Previous research has primarily focused on using PPMC in model checking for unidimensional and multidimensional IRT models for dichotomous data, and has paid little attention to polytomous models. A Monte Carlo simulation was conducted to investigate the performance of PPMC in detecting different sources of misfit for the partial credit model family. Results showed that the PPMC method, in combination with appropriate discrepancy measures, had adequate power in detecting different sources of misfit for the partial credit model family. Global odds ratio and item total correlation exhibited specific patterns in detecting the absence of the slope parameter, whereas Yen's Q1 was found to be promising in the detection of misfit caused by the constant category intersection parameter constraint across items. (PsycINFO Database Record
Hypersonic: Model Analysis and Checking in the Cloud
DEFF Research Database (Denmark)
Acretoaie, Vlad; Störrle, Harald
2014-01-01
Context: Modeling tools are traditionally delivered as monolithic desktop applications, optionally extended by plug-ins or special purpose central servers. This delivery model suffers from several drawbacks, ranging from poor scalability to diffcult maintenance and the proliferation of \\shelfware...... in combination with Prolog as an implementation language, we are able to transform MACH from a command line tool into the first Web-based model clone detection service with remarkably little effort....
Closing open SDL-systems for model checking with DTSpin
Ioustinova, N.; Sidorova, N.; Steffen, M.
2002-01-01
Model checkers like Spin can handle closed reactive systems, only. Thus to handle open systems, in particular when using assume-guarantee reasoning, we need to be able to close (sub-)systems, which is commonly done by adding an environment process. For models with asynchronous message-passing commun
LTSmin: high-performance language-independent model checking
Kant, Gijs; Laarman, Alfons; Meijer, Jeroen; Pol, van de Jaco; Blom, Stefan; Dijk, van Tom; Baier, Christel; Tinelli, Cesare
2015-01-01
In recent years, the LTSmin model checker has been extended with support for several new modelling languages, including probabilistic (Mapa) and timed systems (Uppaal). Also, connecting additional language front-ends or ad-hoc state-space generators to LTSmin was simplified using custom C-code. From
Bounded Satisfiability for PCTL
Bertrand, Nathalie; Schewe, Sven
2012-01-01
While model checking PCTL for Markov chains is decidable in polynomial-time, the decidability of PCTL satisfiability, as well as its finite model property, are long standing open problems. While general satisfiability is an intriguing challenge from a purely theoretical point of view, we argue that general solutions would not be of interest to practitioners: such solutions could be too big to be implementable or even infinite. Inspired by bounded synthesis techniques, we turn to the more applied problem of seeking models of a bounded size: we restrict our search to implementable -- and therefore reasonably simple -- models. We propose a procedure to decide whether or not a given PCTL formula has an implementable model by reducing it to an SMT problem. We have implemented our techniques and found that they can be applied to the practical problem of sanity checking -- a procedure that allows a system designer to check whether their formula has an unexpectedly small model.
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.
A Case Study in Model Checking Software Systems.
1996-04-01
two formal objects compared are a nite state machine model of the software system, and as before, a speci cation written in some mathematical logic...C:Dt = ffg, and At = ffC = fSg. 4.1.1 State Machine Model The top graph in Figure 2 shows the state transition graphs for the client, and the bottom...follows from 2 above, because once the client discovers d is invalid it discards it. Thus At = ; or At = fdC = dSg. 4.3.1 State Machine Model For the Coda
Vulnerable Derivatives and Good Deal Bounds: A Structural Model
DEFF Research Database (Denmark)
Murgoci, Agatha
2013-01-01
a 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...
An Evaluation Framework for Energy Aware Buildings using Statistical Model Checking
DEFF Research Database (Denmark)
David, Alexandre; Du, DeHui; Larsen, Kim Guldstrand
2012-01-01
extend in this paper the modelling formalism of the tool Uppaal-smc to stochastic hybrid automata, thus providing the expressive power required for modeling complex cyber-physical systems. The application of Statistical Model Checking provides a highly scalable technique for analyzing performance...
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.
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.
Experimental bounds on collapse models from gravitational wave detectors
Carlesso, Matteo; Bassi, Angelo; Falferi, Paolo; Vinante, Andrea
2016-12-01
Wave function collapse models postulate a fundamental breakdown of the quantum superposition principle at the macroscale. Therefore, experimental tests of collapse models are also fundamental tests of quantum mechanics. Here, we compute the upper bounds on the collapse parameters, which can be inferred by the gravitational wave detectors LIGO, LISA Pathfinder, and AURIGA. We consider the most widely used collapse model, the continuous spontaneous localization (CSL) model. We show that these experiments exclude a huge portion of the CSL parameter space, the strongest bound being set by the recently launched space mission LISA Pathfinder. We also rule out a proposal for quantum-gravity-induced decoherence.
Dynamic Delayed Duplicate Detection for External Memory Model Checking
DEFF Research Database (Denmark)
Evangelista, Sami
2008-01-01
Duplicate detection is an expensive operation of disk-based model checkers. It consists of comparing some potentially new states, the candidate states, to previous visited states. We propose a new approach to this technique called dynamic delayed duplicate detection. This one exploits some typical...
UML Statechart Fault Tree Generation By Model Checking
DEFF Research Database (Denmark)
Herbert, Luke Thomas; Herbert-Hansen, Zaza Nadja Lee
of the popular Business Process Modelling and Nota-tion (BPMN) language. To capture uncertainty and unreliability in workflows, we extend this formalism with probabilistic non-deterministic branching.We present an algorithm that allows for exhaustive gen-eration of possible error states that could arise in ex...
Performance evaluation:= (process algebra + model checking) x Markov chains
Hermanns, H.; Katoen, J.P.; Larsen, Kim G.; Nielsen, Mogens
2001-01-01
Markov chains are widely used in practice to determine system performance and reliability characteristics. The vast majority of applications considers continuous-time Markov chains (CTMCs). This tutorial paper shows how successful model specification and analysis techniques from concurrency theory c
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...
Model-Checking Real-Time Control Programs
DEFF Research Database (Denmark)
Iversen, T. K.; Kristoffersen, K. J.; Larsen, Kim Guldstrand
2000-01-01
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...
CheckMATE: Confronting your Favourite New Physics Model with LHC Data
Drees, Manuel; Kim, Jong Soo; Schmeier, Daniel; Tattersall, Jamie
2013-01-01
In the first three years of running, the LHC has delivered a wealth of new data that is now being analysed. With over 20 fb$^{-1}$ of integrated luminosity, both ATLAS and CMS have performed many searches for new physics that theorists are eager to test their model against. However, tuning the detector simulations, understanding the particular analysis details and interpreting the results can be a tedious task. CheckMATE (Check Models At Terascale Energies) is a program package which accepts simulated event files in many formats for any model. The program then determines whether the model is excluded or not at 95% C.L. by comparing to many recent experimental analyses. Furthermore the program can calculate confidence limits and provide detailed information about signal regions of interest. It is simple to use and the program structure allows for easy extensions to upcoming LHC results in the future. CheckMATE can be found at: http://checkmate.hepforge.org
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 ZigBee Security using Stochastic Model Checking
Yuksel, Ender; Nielson, Hanne Riis; Nielson, Flemming; Fruth, Matthias; Kwiatkowska, Marta
2012-01-01
ZigBee is a fairly new but promising wireless sensor network standard that offers the advantages of simple and low resource communication. Nevertheless, security is of great concern to ZigBee, and enhancements are prescribed in the latest ZigBee specication: ZigBee-2007. In this technical report, we identify an important gap in the specification on key updates, and present a methodology for determining optimal key update policies and security parameters. We exploit the stochastic model checki...
Energy Technology Data Exchange (ETDEWEB)
Ben Said, Nader; Bregulla, Wolfgang; Kalk, Andreas [Westinghouse Electric Germany GmbH, Mannheim (Germany)
2009-07-01
Westinghouse Electric Germany GmbH has developed fluid dynamic models for medium-actuated armatures using the thermal hydraulic code RELAP5 in order to reach a more realistic description of the armature behavior including fluid-structure interactions in case of transient flow conditions in piping systems. The contribution is concerned with the modeling of damped check valves. The model allows the description of the behavior during opening and closure of a check armature. The calculated results show good agreement with the available measured data.
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.
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...
Model-Checking Web Services Business Activity Protocols
DEFF Research Database (Denmark)
Marques, Abinoam P.; Ravn, Anders Peter; Srba, Jiri
2013-01-01
Web Services Business Activity specification defines two coordination protocols BAwCC (Business Agreement with Coordination Completion) and BAwPC (Business Agreement with Participant Completion)that ensure a consistent agreement on the outcome of long-running distributed applications. In order...... to verify fundamental properties of the protocols we provide formal analyses in the model checker UPPAAL.Our analyses are supported by a newly developed tool chain,where in the first step we translatetables with state-transition protocol descriptionsinto an intermediate XML format, and in the second step we...... translate this format into a network of communicating state machines directly suitable for verification in UPPAAL.Our results show that the WS-BA protocols, as described in the standard specification, violate correct operation by reaching invalid statesfor all underlying communication media except...
A "Brutus" model checking of a spi-calculus dialect (Extended Abstract)
Gnesi, S.; Latella, D.; Lenzini, G.
2000-01-01
This paper proposes a preliminary framework in which protocols, expressed in a dialect of the spi-calculus, can be verified using model checking algorithms. In particular we define a formal semantics for a dialect of the spi-calculus based on labeled transition systems in such a way that the model c
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
Energy Technology Data Exchange (ETDEWEB)
Lahtinen, J.; Bjoerkman, K.; Valkonen, J.; Frits, J.; Niemelae, I.
2010-12-15
Digital instrumentation and control (I and C) systems containing programmable logic controllers are challenging to verify. They enable complicated control functions and the state spaces (number of distinct values of inputs, outputs and internal memory) of the designs easily become too large for comprehensive manual inspection. Model checking is a formal method that can be used for verifying that systems have been correctly designed. A number of efficient model checking systems are available which provide analysis tools that are able to determine automatically whether a given state machine model satisfies the desired safety properties. The practical case analysed in this research project is called an 'emergency diesel generator control system' and its purpose is to provide reserve power to critical devices and computers that must be available without interruption. This report describes 1) the development of a compositional approach for checking the models in large system designs, 2) the development of a modular model checking approach for modelling function block diagrams with the Uppaal model checker and 3) the experience of utilising the new modelling approaches in practice. (orig.)
On model checking the dynamics of object-based software : a foundational approach
Distefano, Dino Salvo
2003-01-01
This dissertation is concerned with software verication, in particular automated techniques to assess the correct functioning of object-based programs. We focus on the dynamic aspects of these programs and consider model-checking based verication techniques. The major obstacle to the design of model
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
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.
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 desi......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...
DEFF Research Database (Denmark)
ter Beek, Maurice H.; Legay, Axel; Lluch Lafuente, Alberto
2015-01-01
We investigate the suitability of statistical model checking techniques for analysing quantitative properties of software product line models with probabilistic aspects. For this purpose, we enrich the feature-oriented language FLAN with action rates, which specify the likelihood of exhibiting...... particular behaviour or of installing features at a specific moment or in a specific order. The enriched language (called PFLAN) allows us to specify models of software product lines with probabilistic configurations and behaviour, e.g. by considering a PFLAN semantics based on discrete-time Markov chains....... The Maude implementation of PFLAN is combined with the distributed statistical model checker MultiVeStA to perform quantitative analyses of a simple product line case study. The presented analyses include the likelihood of certain behaviour of interest (e.g. product malfunctioning) and the expected average...
Free-Energy Bounds for Hierarchical Spin Models
Castellana, Michele; Barra, Adriano; Guerra, Francesco
2014-04-01
In this paper we study two non-mean-field (NMF) spin models built on a hierarchical lattice: the hierarchical Edward-Anderson model (HEA) of a spin glass, and Dyson's hierarchical model (DHM) of a ferromagnet. For the HEA, we prove the existence of the thermodynamic limit of the free energy and the replica-symmetry-breaking (RSB) free-energy bounds previously derived for the Sherrington-Kirkpatrick model of a spin glass. These RSB mean-field bounds are exact only if the order-parameter fluctuations (OPF) vanish: given that such fluctuations are not negligible in NMF models, we develop a novel strategy to tackle part of OPF in hierarchical models. The method is based on absorbing part of OPF of a block of spins into an effective Hamiltonian of the underlying spin blocks. We illustrate this method for DHM and show that, compared to the mean-field bound for the free energy, it provides a tighter NMF bound, with a critical temperature closer to the exact one. To extend this method to the HEA model, a suitable generalization of Griffith's correlation inequalities for Ising ferromagnets is needed: since correlation inequalities for spin glasses are still an open topic, we leave the extension of this method to hierarchical spin glasses as a future perspective.
Assessing the hydrological effect of the check dams in the Loess Plateau, China by model simulations
Directory of Open Access Journals (Sweden)
Y. D. Xu
2012-12-01
Full Text Available Check dams are commonly used for soil conservation. In the Loess Plateau of China, check dams have been widely constructed as the principal means to retain floodwater and intercept soil sediments since the 1970s. However, little research has been done to quantify the hydrological effects of the check dams.
In this research, the SWAT model (Soil and Water Assessment Tool was applied to simulate the runoff and sediment in the Yanhe watershed in the Loess Plateau. We treated the 1950s to 1960s as "reference period" since there were very few check dams during the period. The model was first calibrated and validated in the "reference period". The calibrated model was then used in the later periods to simulate the hydrological effects of the check dams.
The results showed that the check dams had a regulation effect on runoff and a retention effect on sediment. From 1984 to 1987, the runoff in rainy season (from May to October decreased by 14.7 to 25.9% due to the check dams, while in dry season (from November to the following April, runoff increased by 60.5 to 101.2%; the sediment in rainy season decreased by 34.6 to 48.0%. From 2006 to 2008, the runoff in rainy season decreased by 15.5 to 28.9%, and the runoff in dry season increased by 20.1 to 46.4%; the sediment in rainy season decreased by 79.4 to 85.5%.
Construction of the large number of in the Loess Plateau has enhanced the region's capacity to control the runoff and sediment. In the Yanhe watershed, the annual runoff was reduced by less than 14.3% due to the check dams; and the sediment in rainy season was blocked by up to 85.5%. Thus, check dams are effective measures for soil erosion control in the Loess Plateau.
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.
The dynamics of Bertrand model with bounded rationality
Energy Technology Data Exchange (ETDEWEB)
Zhang Jixiang [School of Economics and Management, Southeast University, Nanjing, Jiangsu 211189 (China)], E-mail: zhang_jixiang@126.com; Da Qingli [School of Economics and Management, Southeast University, Nanjing, Jiangsu 211189 (China); Wang Yanhua [School of Environmental Science and Engineering, Shanghai Jiao Tong University Min Hang, Shanghai 200240 (China)
2009-03-15
The paper considers a Bertrand model with bounded rational. A duopoly game is modelled by two nonlinear difference equations. By using the theory of bifurcations of dynamical systems, the existence and stability for the equilibria of this system are obtained. Numerical simulations used to show bifurcations diagrams, phase portraits for various parameters and sensitive dependence on initial conditions. We observe that an increase of the speed of adjustment of bounded rational player may change the stability of Nash equilibrium point and cause bifurcation and chaos to occur. The analysis and results in this paper are interesting in mathematics and economics.
Bounds on the Tau Magnetic Moments Standard Model and Beyond
González-Sprinberg, G A; Vidal, J; Gonzalez-Sprinberg, Gabriel A.; Santamaria, Arcadi; Vidal, Jorge
2001-01-01
We obtain new bounds for the magnetic dipole moments of the tau lepton. These limits on the magnetic couplings of the tau to the electroweak gauge bosons (gamma, W, Z) are set in a model independent way using the most general effective Lagrangian with the SU(2)_L x U(1)_Y symmetry. Comparison with data from the most precise experiments at high energies shows that the present limits are more stringent than the previous published ones. For the anomalous magnetic moment the bounds are, for the first time, within one order of magnitude of the standard model prediction.
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.
Probability bounds analysis for nonlinear population ecology models.
Enszer, Joshua A; Andrei Măceș, D; Stadtherr, Mark A
2015-09-01
Mathematical models in population ecology often involve parameters that are empirically determined and inherently uncertain, with probability distributions for the uncertainties not known precisely. Propagating such imprecise uncertainties rigorously through a model to determine their effect on model outputs can be a challenging problem. We illustrate here a method for the direct propagation of uncertainties represented by probability bounds though nonlinear, continuous-time, dynamic models in population ecology. This makes it possible to determine rigorous bounds on the probability that some specified outcome for a population is achieved, which can be a core problem in ecosystem modeling for risk assessment and management. Results can be obtained at a computational cost that is considerably less than that required by statistical sampling methods such as Monte Carlo analysis. The method is demonstrated using three example systems, with focus on a model of an experimental aquatic food web subject to the effects of contamination by ionic liquids, a new class of potentially important industrial chemicals.
Bandwidth and Wavefront Reduction for Static Variable Ordering in Symbolic Model Checking
Meijer, Jeroen; Pol, van de Jaco
2015-01-01
We demonstrate the applicability of bandwidth and wavefront reduction algorithms to static variable ordering. In symbolic model checking event locality plays a major role in time and memory usage. For example, in Petri nets event locality can be captured by dependency matrices, where nonzero entries
A practical approach to model checking Duration Calculus using Presburger Arithmetic
DEFF Research Database (Denmark)
Hansen, Michael Reichhardt; Dung, Phan Anh; Brekling, Aske Wiid
2014-01-01
This paper investigates the feasibility of reducing a model-checking problem K ⊧ ϕ for discrete time Duration Calculus to the decision problem for Presburger Arithmetic. Theoretical results point at severe limitations of this approach: (1) the reduction in Fränzle and Hansen (Int J Softw Inform 3...
Logic Column 19: Symbolic Model Checking for Temporal-Epistemic Logics
Lomuscio, Alessio
2007-01-01
This article surveys some of the recent work in verification of temporal epistemic logic via symbolic model checking, focusing on OBDD-based and SAT-based approaches for epistemic logics built on discrete and real-time branching time temporal logics.
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...
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
Discrete fluid power force systems have been proposed as the primary stage for Wave Energy Converters (WEC’s) when converting ocean waves into electricity, this to improve the overall efficiency of wave energy devices. This paper presents a model based feasibility study of using bidirectional check...
Model Checking - My 27-Year Quest to Overcome the State Explosion Problem
Clarke, Ed
2009-01-01
Model Checking is an automatic verification technique for state-transition systems that are finite=state or that have finite-state abstractions. In the early 1980 s in a series of joint papers with my graduate students E.A. Emerson and A.P. Sistla, we proposed that Model Checking could be used for verifying concurrent systems and gave algorithms for this purpose. At roughly the same time, Joseph Sifakis and his student J.P. Queille at the University of Grenoble independently developed a similar technique. Model Checking has been used successfully to reason about computer hardware and communication protocols and is beginning to be used for verifying computer software. Specifications are written in temporal logic, which is particularly valuable for expressing concurrency properties. An intelligent, exhaustive search is used to determine if the specification is true or not. If the specification is not true, the Model Checker will produce a counterexample execution trace that shows why the specification does not hold. This feature is extremely useful for finding obscure errors in complex systems. The main disadvantage of Model Checking is the state-explosion problem, which can occur if the system under verification has many processes or complex data structures. Although the state-explosion problem is inevitable in worst case, over the past 27 years considerable progress has been made on the problem for certain classes of state-transition systems that occur often in practice. In this talk, I will describe what Model Checking is, how it works, and the main techniques that have been developed for combating the state explosion problem.
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...
Model Checking Games for a Fair Branching-Time Temporal Epistemic Logic
Huang, Xiaowei; van der Meyden, Ron
Model checking games are instances of Hintikka's game semantics for logic used for purposes of debugging systems verification models. Previous work in the area has developed these games for branching time logic. The paper develops an extension to a logic that adds epistemic operators, and interprets the branching time operators with respect to fairness constraints. The implementation of the extended games in the epistemic model checker MCK is described.
Pârvu, Ovidiu; 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
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.
Lambda(1405) in the bound state soliton model
Schat, C L; Gobbi, C; Schat, C L; Scoccola, N N; Gobbi, C
1994-01-01
The strong and electromagnetic properties of the Lambda(1405) hyperon are studied in the framework of the bound state soliton model. We explicitly evaluate the strong coupling constant g(Lambda^*-N-K), the Lambda^* magnetic moment, mean square radii and radiative decay amplitudes. The results are shown to be in general agreement with available empirical data. A comparison with results of other models is also presented.
Bayesian analysis for OPC modeling with film stack properties and posterior predictive checking
Burbine, Andrew; Fenger, Germain; Sturtevant, John; Fryer, David
2016-10-01
The use of optical proximity correction (OPC) demands increasingly accurate models of the photolithographic process. Model building and analysis techniques in the data science community have seen great strides in the past two decades which make better use of available information. This paper expands upon Bayesian analysis methods for parameter selection in lithographic models by increasing the parameter set and employing posterior predictive checks. Work continues with a Markov chain Monte Carlo (MCMC) search algorithm to generate posterior distributions of parameters. Models now include wafer film stack refractive indices, n and k, as parameters, recognizing the uncertainties associated with these values. Posterior predictive checks are employed as a method to validate parameter vectors discovered by the analysis, akin to cross validation.
CheckMATE: Confronting your favourite new physics model with LHC data
Drees, Manuel; Dreiner, Herbert K.; Kim, Jong Soo; Schmeier, Daniel; Tattersall, Jamie
2015-02-01
In the first three years of running, the LHC has delivered a wealth of new data that is now being analysed. With over 20 fb-1 of integrated luminosity, both ATLAS and CMS have performed many searches for new physics that theorists are eager to test their model against. However, tuning the detector simulations, understanding the particular analysis details and interpreting the results can be a tedious task. CheckMATE (Check Models At Terascale Energies) is a program package which accepts simulated event files in many formats for any model. The program then determines whether the model is excluded or not at 95% C.L. by comparing to many recent experimental analyses. Furthermore the program can calculate confidence limits and provide detailed information about signal regions of interest. It is simple to use and the program structure allows for easy extensions to upcoming LHC results in the future.
Key management and encryption under the bounded storage model.
Energy Technology Data Exchange (ETDEWEB)
Draelos, Timothy John; Neumann, William Douglas; Lanzone, Andrew J.; Anderson, William Erik
2005-11-01
There are several engineering obstacles that need to be solved before key management and encryption under the bounded storage model can be realized. One of the critical obstacles hindering its adoption is the construction of a scheme that achieves reliable communication in the event that timing synchronization errors occur. One of the main accomplishments of this project was the development of a new scheme that solves this problem. We show in general that there exist message encoding techniques under the bounded storage model that provide an arbitrarily small probability of transmission error. We compute the maximum capacity of this channel using the unsynchronized key-expansion as side-channel information at the decoder and provide tight lower bounds for a particular class of key-expansion functions that are pseudo-invariant to timing errors. Using our results in combination with Dziembowski et al. [11] encryption scheme we can construct a scheme that solves the timing synchronization error problem. In addition to this work we conducted a detailed case study of current and future storage technologies. We analyzed the cost, capacity, and storage data rate of various technologies, so that precise security parameters can be developed for bounded storage encryption schemes. This will provide an invaluable tool for developing these schemes in practice.
Thermodynamic models for bounding pressurant mass requirements of cryogenic tanks
Vandresar, Neil T.; Haberbusch, Mark S.
1994-01-01
Thermodynamic models have been formulated to predict lower and upper bounds for the mass of pressurant gas required to pressurize a cryogenic tank and then expel liquid from the tank. Limiting conditions are based on either thermal equilibrium or zero energy exchange between the pressurant gas and initial tank contents. The models are independent of gravity level and allow specification of autogenous or non-condensible pressurants. Partial liquid fill levels may be specified for initial and final conditions. Model predictions are shown to successfully bound results from limited normal-gravity tests with condensable and non-condensable pressurant gases. Representative maximum collapse factor maps are presented for liquid hydrogen to show the effects of initial and final fill level on the range of pressurant gas requirements. Maximum collapse factors occur for partial expulsions with large final liquid fill fractions.
Abstraction for Epistemic Model Checking of Dining Cryptographers-based Protocols
Al-Bataineh, Omar I
2010-01-01
The paper describes an abstraction for protocols that are based on multiple rounds of Chaum's Dining Cryptographers protocol. It is proved that the abstraction preserves a rich class of specifications in the logic of knowledge, including specifications describing what an agent knows about other agents' knowledge. This result can be used to optimize model checking of Dining Cryptographers-based protocols, and applied within a methodology for knowledge-based program implementation and verification. Some case studies of such an application are given, for a protocol that uses the Dining Cryptographers protocol as a primitive in an anonymous broadcast system. Performance results are given for model checking knowledge-based specifications in the concrete and abstract models of this protocol, and some new conclusions about the protocol are derived.
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
and resource usage over a dense-time model. The semantic interpretation of PACOR is defined in the form of a timed transition system expressing the timed behavior and dynamic creation of processes. We define a translation of PACOR systems to Parameterized Stopwatch Automata (PSA). The translation preserves......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...... the 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
, urgentness and resource usage over a dense-time model. The semantic interpretation of PACoR is defined in the form of a timed transition system expressing the timed behavior and dynamic creation of processes. We define a translation of PACoR systems to Parameterized Stopwatch Automata (PSA). The translation......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....
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.
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...... function if only partial failure information is available. An example is provided. © 2012 Copyright Taylor and Francis Group, LLC....
Directory of Open Access Journals (Sweden)
Nacer Tabib
2016-01-01
Full Text Available This paper proposes a new framework based on Binary Decision Diagrams (BDD for the graph distribution problem in the context of explicit model checking. The BDD are yet used to represent the state space for a symbolic verification model checking. Thus, we took advantage of high compression ratio of BDD to encode not only the state space, but also the place where each state will be put. So, a fitness function that allows a good balance load of states over the nodes of an homogeneous network is used. Furthermore, a detailed explanation of how to calculate the inter-site edges between different nodes based on the adapted data structure is presented.
Combining search space partition and search Space partition and abstraction for LTL model checking
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
The state space explosion problem is still the key obstacle for applying model checking to systems of industrial size.Abstraction-based methods have been particularly successful in this regard.This paper presents an approach based on refinement of search space partition and abstraction which combines these two techniques for reducing the complexity of model checking.The refinement depends on the representation of each portion of search space. Especially, search space can be refined stepwise to get a better reduction. As reported in the case study, the Integration of search space partition and abstraction improves the efficiencyof verification with respect to the requirement of memory and obtains significant advantage over the use of each of them in isolation.
On the Model Checking of the SpaceWire Link Interface
Directory of Open Access Journals (Sweden)
Jie Zhang
2013-02-01
Full Text Available In this paper we display a practical approach adopted for the formal verification of SpaceWire using model checking to solve state explosion. SpaceWire is a high-speed, full-duplex serial bus standard which is applied in aerospace, so its functions have a very high accuracy requirements. In order to prove the design of the SpaceWire was faithfully implements the SpaceWire protocol’s specification , we present our experience on the model checking of SpaceWire link interface using the Cadence SMV tool. We applied environment state machine to overcome state explosion and successfully verified a number of relevant properties about transmitter and controller of the SpaceWire in reasonable CPU time.
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.
Institute of Scientific and Technical Information of China (English)
ZHANG WenHui (张文辉)
2003-01-01
Memory is one of the critical resources in model checking. This paper discusses a strategy for reducing peak memory in model checking by case-based partitioning of the search space. This strategy combines model checking for verification of different cases and static analysis or expert judgment for guaranteeing the completeness of the cases. Description of the static analysis is based on using PROMELA as the modeling language. The strategy is applicable to a subset of models including models for verification of certain aspects of protocols.
Detailed model of bouncing drops on a bounded, vibrated bath
Blanchette, Francois; Gilet, Tristan
2014-11-01
We present a detailed model of drops bouncing on a bounded vibrated bath. These drops are known to bounce indefinitely and to exhibit complex and varied vertical dynamics depending on the acceleration of the bath. In addition, in a narrow parameter regime, these drops travel horizontally while being guided by the waves they generate. Our model tracks the drop's vertical radius and position, as well as the eigenmodes of the waves generated via ordinary differential equations only. We accurately capture the vertical dynamics, as well as some of the horizontal dynamics. Our model may be extended to account for interactions with other drops or obstacles, such as slits and corrals.
Model-checking ATL under Imperfect Information and Perfect Recall Semantics is Undecidable
Dima, Catalin
2011-01-01
We propose a formal proof of the undecidability of the model checking problem for alternating- time temporal logic under imperfect information and perfect recall semantics. This problem was announced to be undecidable according to a personal communication on multi-player games with imperfect information, but no formal proof was ever published. Our proof is based on a direct reduction from the non-halting problem for Turing machines.
A Quantum Computing Approach to Model Checking for Advanced Manufacturing Problems
2014-07-01
by using faster languages . The algorithm has several parameters that can be used to try to improve convergence and behavior. In this project we...the abstract models, and reformulated the counterexample checking problem in Linear Temporal Logic (LTL). We wrote a program that read abstract...be reformulated and submitted to the DW2 to be solved. We worked with the NuSMV system developed by Fondazione Bruno Kessler (FBK), CMU, and the
Analysis of DGNB-DK criteria for BIM-based Model Checking automatization
DEFF Research Database (Denmark)
Gade, Peter; Svidt, Kjeld; Jensen, Rasmus Lund
This report includes the results of an analysis of the automation potential of the Danish edition of building sustainability assessment method Deutsche Gesellschaft für Nachhaltiges Bauen (DGNB) for office buildings version 2014 1.1. The analysis investigate the criteria related to DGNB-DK and if......-DK and if they would be suited for automation through the technological concept BIM-based Model Checking (BMC)....
A Novel Algorithm for Intrusion Detection Based on RASL Model Checking
Directory of Open Access Journals (Sweden)
Weijun Zhu
2013-01-01
Full Text Available The interval temporal logic (ITL model checking (MC technique enhances the power of intrusion detection systems (IDSs to detect concurrent attacks due to the strong expressive power of ITL. However, an ITL formula suffers from difficulty in the description of the time constraints between different actions in the same attack. To address this problem, we formalize a novel real-time interval temporal logic—real-time attack signature logic (RASL. Based on such a new logic, we put forward a RASL model checking algorithm. Furthermore, we use RASL formulas to describe attack signatures and employ discrete timed automata to create an audit log. As a result, RASL model checking algorithm can be used to automatically verify whether the automata satisfy the formulas, that is, whether the audit log coincides with the attack signatures. The simulation experiments show that the new approach effectively enhances the detection power of the MC-based intrusion detection methods for a number of telnet attacks, p-trace attacks, and the other sixteen types of attacks. And these experiments indicate that the new algorithm can find several types of real-time attacks, whereas the existing MC-based intrusion detection approaches cannot do that.
Modelling Ca2+ bound Troponin in Excitation Contraction Coupling
Directory of Open Access Journals (Sweden)
Henry G. Zot
2016-09-01
Full Text Available To explain disparate decay rates of cytosolic Ca2+ and structural changes in the thin filaments during a twitch, we model the time course of Ca2+ bound troponin (Tn resulting from the free Ca2+ transient of fast skeletal muscle. In fibers stretched beyond overlap, the decay of Ca2+ as measured by a change in fluo 3 fluorescence is significantly slower than the intensity decay of the meridional 1/38.5 nm-1 reflection of Tn; this is not simply explained by considering only the Ca2+ binding properties of Tn alone (Matsuo, T., Iwamoto, H., and Yagi, N. (2010. Biophys. J. 99, 193-200. We apply a comprehensive model that includes the known Ca2+ binding properties of Tn in the context of the thin filament with and without cycling crossbridges. Calculations based on the model predict that the transient of Ca2+ bound Tn correlates with either the fluo 3 time course in muscle with overlapping thin and thick filaments or the intensity of the meridional 1/38.5 nm-1 reflection in overstretched muscle. Hence, cycling crossbridges delay the dissociation of Ca2+ from Tn. Correlation with the fluo 3 fluorescence change is not causal given that the transient of Ca2+ bound Tn depends on sarcomere length, whereas the fluo-3 fluorescence change does not. Transient positions of tropomyosin calculated from the time course of Ca2+ bound Tn are in reasonable agreement with the transient of measured perturbations of the Tn repeat in overlap and non-overlap muscle preparations.
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.
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.
Quantum position verification in bounded-attack-frequency model
Gao, Fei; Liu, Bin; Wen, QiaoYan
2016-11-01
In 2011, Buhrman et al. proved that it is impossible to design an unconditionally secure quantum position verification (QPV) protocol if the adversaries are allowed to previously share unlimited entanglements. Afterwards, people started to design secure QPV protocols in practical settings, e.g. the bounded-storage model, where the adversaries' pre-shared entangled resources are supposed to be limited. Here we focus on another practical factor that it is very difficult for the adversaries to perform attack operations with unlimitedly high frequency. Concretely, we present a new kind of QPV protocols, called non-simultaneous QPV. And we prove the security of a specific non-simultaneous QPV protocol with the assumption that the frequency of the adversaries' attack operations is bounded, but no assumptions on their pre-shared entanglements or quantum storage. Actually, in our nonsimultaneous protocol, the information whether there comes a signal at present time is also a piece of command. It renders the adversaries "blind", that is, they have to execute attack operations with unlimitedly high frequency no matter whether a signal arrives, which implies the non-simultaneous QPV is also secure in the bounded-storage model.
P2-16: Dual-Bound Model and the Role of Time Bound in Perceptual Decision Making
Directory of Open Access Journals (Sweden)
Daeseob Lim
2012-10-01
Full Text Available The diffusion model (DM encapsulates the dynamics of perceptual decision within a ‘diffusion field’ that is defined by a basis with sensory-evidence (SE and time vectors. At the core of the DM, it assumes that a decision is not made until an evidence particle drifts in the diffusion field and eventually hits one of the two pre-fixed bounds defined in the SE axis. This assumption dictates when and which choice is made by referring to when and which bound will be hit by the evidence particle. What if urgency pressures the decision system to make a choice even when the evidence particle has yet hit the SE bound? Previous modeling attempts at coping with time pressure, despite differences in detail, all manipulated the coordinate of SE bounds. Here, we offer a novel solution by adopting another bound on the time axis. This ‘dual-bound’ model (DBM posits that decisions can also be made when the evidence particle hits a time bound, which is determined on a trial-by-trial basis by a ‘perceived time interval’ – how long the system can stay in the ‘diffusion’ field. The classic single-bound model (SBM exhibited systematic errors in predicting both the reaction time distributions and the time-varying bias in choice. Those errors were not corrected by previously proposed variants of the SBM until the time bound was introduced. The validity of the DBM was further supported by the strong across-individual correlation between observed precision of interval timing and the predicted trial-by-trial variability of the time bound.
A rule-based approach to model checking of UML state machines
Grobelna, Iwona; Grobelny, Michał; Stefanowicz, Łukasz
2016-12-01
In the paper a new approach to formal verification of control process specification expressed by means of UML state machines in version 2.x is proposed. In contrast to other approaches from the literature, we use the abstract and universal rule-based logical model suitable both for model checking (using the nuXmv model checker), but also for logical synthesis in form of rapid prototyping. Hence, a prototype implementation in hardware description language VHDL can be obtained that fully reflects the primary, already formally verified specification in form of UML state machines. Presented approach allows to increase the assurance that implemented system meets the user-defined requirements.
K¯ nuclear bound states in a dynamical model
Mareš, J.; Friedman, E.; Gal, A.
2006-05-01
A comprehensive data base of K-atom level shifts and widths is re-analyzed in order to study the density dependence of the K¯-nuclear optical potential. Significant departure from a tρ form is found only for ρ(r)/ρ ≲ 0.2 and extrapolation to nuclear-matter density ρ yields an attractive potential, about 170 MeV deep. Partial restoration of chiral symmetry compatible with pionic atoms and low-energy pion-nuclear data plays no role at the relevant low-density regime, but this effect is not ruled out at densities of order ρ and beyond. K¯-nuclear bound states are generated across the periodic table self consistently, using a relativistic mean-field model Lagrangian which couples the K¯ to the scalar and vector meson fields mediating the nuclear interactions. The reduced phase space available for K¯ absorption from these bound states is taken into account by adding an energy-dependent imaginary term which underlies the corresponding K¯-nuclear level widths, with a strength required by fits to the atomic data. Substantial polarization of the core nucleus is found for light nuclei, and the binding energies and widths calculated in this dynamical model differ appreciably from those calculated for a static nucleus. A wide range of binding energies is spanned by varying the K¯ couplings to the meson fields. Our calculations provide a lower limit of Γ=50±10 MeV on the width of nuclear bound states for K¯-binding energy in the range B˜100-200 MeV. Comments are made on the interpretation of the FINUDA experiment at DAΦNE which claimed evidence for deeply bound Kpp states in light nuclei.
Combining Explicit and Symbolic Approaches for Better On-the-Fly LTL Model Checking
Duret-Lutz, Alexandre; Poitrenaud, Denis; Thierry-Mieg, Yann
2011-01-01
We present two new hybrid techniques that replace the synchronized product used in the automata-theoretic approach for LTL model checking. The proposed products are explicit graphs of aggregates (symbolic sets of states) that can be interpreted as B\\"uchi automata. These hybrid approaches allow on the one hand to use classical emptiness-check algorithms and build the graph on-the-fly, and on the other hand, to have a compact encoding of the state space thanks to the symbolic representation of the aggregates. The Symbolic Observation Product assumes a globally stuttering property (e.g., LTL \\ X) to aggregate states. The Self-Loop Aggregation Product} does not require the property to be globally stuttering (i.e., it can tackle full LTL), but dynamically detects and exploits a form of stuttering where possible. Our experiments show that these two variants, while incomparable with each other, can outperform other existing approaches.
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...
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.
Applying Model Checking to Generate Model-Based Integration Tests from Choreography Models
Wieczorek, Sebastian; Kozyura, Vitaly; Roth, Andreas; Leuschel, Michael; Bendisposto, Jens; Plagge, Daniel; Schieferdecker, Ina
Choreography models describe the communication protocols between services. Testing of service choreographies is an important task for the quality assurance of service-based systems as used e.g. in the context of service-oriented architectures (SOA). The formal modeling of service choreographies enables a model-based integration testing (MBIT) approach. We present MBIT methods for our service choreography modeling approach called Message Choreography Models (MCM). For the model-based testing of service choreographies, MCMs are translated into Event-B models and used as input for our test generator which uses the model checker ProB.
An Integrated Approach of Model checking and Temporal Fault Tree for System Safety Analysis
Energy Technology Data Exchange (ETDEWEB)
Koh, Kwang Yong; Seong, Poong Hyun [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)
2009-10-15
Digitalization of instruments and control systems in nuclear power plants offers the potential to improve plant safety and reliability through features such as increased hardware reliability and stability, and improved failure detection capability. It however makes the systems and their safety analysis more complex. Originally, safety analysis was applied to hardware system components and formal methods mainly to software. For software-controlled or digitalized systems, it is necessary to integrate both. Fault tree analysis (FTA) which has been one of the most widely used safety analysis technique in nuclear industry suffers from several drawbacks as described in. In this work, to resolve the problems, FTA and model checking are integrated to provide formal, automated and qualitative assistance to informal and/or quantitative safety analysis. Our approach proposes to build a formal model of the system together with fault trees. We introduce several temporal gates based on timed computational tree logic (TCTL) to capture absolute time behaviors of the system and to give concrete semantics to fault tree gates to reduce errors during the analysis, and use model checking technique to automate the reasoning process of FTA.
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, ...
Bounding SAR ATR performance based on model similarity
Boshra, Michael; Bhanu, Bir
1999-08-01
Similarity between model targets plays a fundamental role in determining the performance of target recognition. We analyze the effect of model similarity on the performance of a vote- based approach for target recognition from SAR images. In such an approach, each model target is represented by a set of SAR views sampled at a variety of azimuth angles and a specific depression angle. Both model and data views are represented by locations of scattering centers, which are peak features. The model hypothesis (view of a specific target and associated location) corresponding to a given data view is chosen to be the one with the highest number of data-supported model features (votes). We address three issues in this paper. Firstly, we present a quantitative measure of the similarity between a pair of model views. Such a measure depends on the degree of structural overlap between the two views, and the amount of uncertainty. Secondly, we describe a similarity- based framework for predicting an upper bound on recognition performance in the presence of uncertainty, occlusion and clutter. Thirdly, we validate the proposed framework using MSTAR public data, which are obtained under different depression angles, configurations and articulations.
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.
Enriched MU-Calculi Module Checking
Ferrante, Alessandro; Parente, Mimmo
2008-01-01
The model checking problem for open systems has been intensively studied in the literature, for both finite-state (module checking) and infinite-state (pushdown module checking) systems, with respect to Ctl and Ctl*. In this paper, we further investigate this problem with respect to the Mu-calculus enriched with nominals and graded modalities (hybrid graded Mu-calculus), in both the finite-state and infinite-state settings. Using an automata-theoretic approach, we show that hybrid graded Mu-calculus module checking is solvable in exponential time, while hybrid graded Mu-calculus pushdown module checking is solvable in double-exponential time. These results are also tight since they match the known lower bounds for Ctl. We also investigate the module checking problem with respect to the hybrid graded Mu-calculus enriched with inverse programs (Fully enriched Mu-calculus): by showing a reduction from the domino problem, we show its undecidability. We conclude with a short overview of the model checking problem ...
Three-nucleon bound states using realistic potential models
Nogga, A.; Kievsky, A.; Kamada, H.; Glöckle, W.; Marcucci, L. E.; Rosati, S.; Viviani, M.
2003-03-01
The bound states of 3H and 3He have been calculated by using the Argonne v18 plus the Urbana IX three-nucleon potential. The isospin T=3/2 state have been included in the calculations as well as the n-p mass difference. The 3H-3He mass difference has been evaluated through the charge-dependent terms explicitly included in the two-body potential. The calculations have been performed using two different methods: the solution of the Faddeev equations in momentum space and the expansion on the correlated hyperspherical harmonic basis. The results are in agreement within 0.1% and can be used as benchmark tests. Results for the charge-dependent Bonn interaction in conjunction with the Tucson-Melbourne three-nucleon force are also presented. It is shown that the 3H and 3He binding energy difference can be predicted model independently.
The three-nucleon bound state using realistic potential models
Nogga, A; Kamada, H; Glöckle, W; Marcucci, L E; Rosati, S; Viviani, M
2003-01-01
The bound states of $^3$H and $^3$He have been calculated using the Argonne $v_{18}$ plus the Urbana three-nucleon potential. The isospin $T=3/2$ state have been included in the calculations as well as the $n$-$p$ mass difference. The $^3$H-$^3$He mass difference has been evaluated through the charge dependent terms explicitly included in the two-body potential. The calculations have been performed using two different methods: the solution of the Faddeev equations in momentum space and the expansion on the correlated hyperspherical harmonic basis. The results are in agreement within 0.1% and can be used as benchmark tests. Results for the CD-Bonn interaction are also presented. It is shown that the $^3$H and $^3$He binding energy difference can be predicted model independently.
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.
String Models for the Heavy Quark-Antiquark Bound States.
Tse, Sze-Man
1988-12-01
The heavy quark-antiquark bound state is examined in the phenomenological string models. Specifically, the Nambu-Goto model and the Polyakov's smooth string model are studied in the large-D limit, D being the number of transverse space-time dimensions. The static potential V(R) is extracted in both models in the large-D limit. In the former case, this amounts to the usual saddle point calculation. In the latter case, the renormalized, physical string tension is expressed in terms of the bare string tension and the extrinsic curvature coupling. A systematic loop expansion of V(R) is developed and carried out explicitly to one loop order, with the two loops result presented without detail. For large separations R, the potential is linear in R with corrections of order 1/R. The coefficient of the 1/R Luscher term has the universal value -piD/24 to any finite order in the loop expansion. For very small separations R, the potential V(R) is also proportional to 1/R with a coefficient twice that of Luscher's term. The corrections are logarithmically small. Polyakov's smooth string model is extended to the finite temperature situation. The temperature dependence of the string tension is investigated in the large-D limit. The effective string tension is calculated to the second order in the loop expansion. At low temperature, it differs from that of the Nambu-Goto model only by terms that fall exponentially with inverse temperature. Comparison of the potential V(R) in the smooth string model with lattice gauge calculation and hadron spectroscopy data yields a consistent result.
Enabling model checking for collaborative process analysis: from BPMN to `Network of Timed Automata'
Mallek, Sihem; Daclin, Nicolas; Chapurlat, Vincent; Vallespir, Bruno
2015-04-01
Interoperability is a prerequisite for partners involved in performing collaboration. As a consequence, the lack of interoperability is now considered a major obstacle. The research work presented in this paper aims to develop an approach that allows specifying and verifying a set of interoperability requirements to be satisfied by each partner in the collaborative process prior to process implementation. To enable the verification of these interoperability requirements, it is necessary first and foremost to generate a model of the targeted collaborative process; for this research effort, the standardised language BPMN 2.0 is used. Afterwards, a verification technique must be introduced, and model checking is the preferred option herein. This paper focuses on application of the model checker UPPAAL in order to verify interoperability requirements for the given collaborative process model. At first, this step entails translating the collaborative process model from BPMN into a UPPAAL modelling language called 'Network of Timed Automata'. Second, it becomes necessary to formalise interoperability requirements into properties with the dedicated UPPAAL language, i.e. the temporal logic TCTL.
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...
Verification of communication protocols in web services model-checking service compositions
Tari, Zahir; Mukherjee, Anshuman
2014-01-01
Gathers recent advancements in the field of self-organizing wireless sensor networks and provides readers with the essential, state-of-the-art information about sensor networking. In the near future, wireless sensor networks will become an integral part of our day-to-day life. To solve different sensor networking related issues, researchers have put a great deal of effort into coming up with innovative ideas. Verification of Communication Protocols in Web Services: Model-Checking Service Compositions gathers recent advancements in the field of self-organizing wireless sensor networks and provides readers with integral information about sensor networking. It introduces current technological trends, particularly in node organization, and provides implementation details of each networking type to help readers set up sensor networks in their related job fields. In addition, it identifies the limitations of current technologies, as well as future research directions.
Energy Technology Data Exchange (ETDEWEB)
Pires, Luis F.G.; Barreto, Claudio V.; Sarmento, Renata C. [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil). Dept. de Engenharia Mecanica. Nucleo de Simulacao Termohidraulica de Dutos (SIMDUT)
2005-07-01
As usual a shipping terminal contains a header and its diameter is smaller than the main pipeline diameter. This diameter reduction amplifies the effects caused by hydraulic transients. It was noticed during simulations that check valves without dynamic modeling may introduce some error in the maximum pressure results without a dynamic model approach. The current paper uses commercial pipeline simulation software to model the dynamic behavior of the check valves. It was studied the header diameter influence and how the check valve model type may change the maximum pressure in the pipeline. It was proved that even a pipeline that works with low pressure and small elevation drop needs a detailed valve modeling to prevent the calculation of unreal pressure values in the region with diameter reduction. (author)
Rigorous bounds on the free energy of electron-phonon models
Raedt, Hans De; Michielsen, Kristel
1997-01-01
We present a collection of rigorous upper and lower bounds to the free energy of electron-phonon models with linear electron-phonon interaction. These bounds are used to compare different variational approaches. It is shown rigorously that the ground states corresponding to the sharpest bounds do no
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...
Rich Counter-Examples for Temporal-Epistemic Logic Model Checking
Busard, Simon; 10.4204/EPTCS.78.4
2012-01-01
Model checking verifies that a model of a system satisfies a given property, and otherwise produces a counter-example explaining the violation. The verified properties are formally expressed in temporal logics. Some temporal logics, such as CTL, are branching: they allow to express facts about the whole computation tree of the model, rather than on each single linear computation. This branching aspect is even more critical when dealing with multi-modal logics, i.e. logics expressing facts about systems with several transition relations. A prominent example is CTLK, a logic that reasons about temporal and epistemic properties of multi-agent systems. In general, model checkers produce linear counter-examples for failed properties, composed of a single computation path of the model. But some branching properties are only poorly and partially explained by a linear counter-example. This paper proposes richer counter-example structures called tree-like annotated counter-examples (TLACEs), for properties in Action-R...
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
One of the main features that distinguish split-plot experiments from other experiments is that they involve two types of experimental errors: the whole-plot (WP) error and the subplot (SP) error. Taking this into consideration is very important when computing measures of adequacy of fit for split......-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...
Notes on shear viscosity bound violation in anisotropic models
Ge, Xian-Hui
2015-01-01
The shear viscosity bound violation in Einstein gravity for anisotropic black branes is discussed, with the aim of constraining the deviation of the shear viscosity-entropy density ratio from the shear viscosity bound using causality and thermodynamics analysis. The results show that no stringent constraints can be imposed. The diffusion bound in anisotropic phases is also studied. Ultimately, it is concluded that shear viscosity violation always occurs in cases where the equation of motion of the metric fluctuations cannot be written in a form identical to that of the minimally coupled massless scalar fields.
Rich Counter-Examples for Temporal-Epistemic Logic Model Checking
Directory of Open Access Journals (Sweden)
Simon Busard
2012-02-01
Full Text Available Model checking verifies that a model of a system satisfies a given property, and otherwise produces a counter-example explaining the violation. The verified properties are formally expressed in temporal logics. Some temporal logics, such as CTL, are branching: they allow to express facts about the whole computation tree of the model, rather than on each single linear computation. This branching aspect is even more critical when dealing with multi-modal logics, i.e. logics expressing facts about systems with several transition relations. A prominent example is CTLK, a logic that reasons about temporal and epistemic properties of multi-agent systems. In general, model checkers produce linear counter-examples for failed properties, composed of a single computation path of the model. But some branching properties are only poorly and partially explained by a linear counter-example. This paper proposes richer counter-example structures called tree-like annotated counter-examples (TLACEs, for properties in Action-Restricted CTL (ARCTL, an extension of CTL quantifying paths restricted in terms of actions labeling transitions of the model. These counter-examples have a branching structure that supports more complete description of property violations. Elements of these counter-examples are annotated with parts of the property to give a better understanding of their structure. Visualization and browsing of these richer counter-examples become a critical issue, as the number of branches and states can grow exponentially for deeply-nested properties. This paper formally defines the structure of TLACEs, characterizes adequate counter-examples w.r.t. models and failed properties, and gives a generation algorithm for ARCTL properties. It also illustrates the approach with examples in CTLK, using a reduction of CTLK to ARCTL. The proposed approach has been implemented, first by extending the NuSMV model checker to generate and export branching counter
Model checking of time Petri nets using the state class timed automaton
DEFF Research Database (Denmark)
Lime, Didier; Roux, Olivier H.
2006-01-01
In this paper, we propose a method for building the state class graph of a bounded time Petri net (TPN) as a timed automaton (TA), which we call the state class timed automaton. We consider bounded TPN, whose underlying net is not necessarily bounded. We prove that our translation preserves...
Simulation Modeling of a Check-in and Medication Reconciliation Ambulatory Clinic Kiosk
Directory of Open Access Journals (Sweden)
Blake Lesselroth
2011-01-01
Full Text Available Gaps in information about patient medication adherence may contribute to preventable adverse drug events and patient harm. Hence, health-quality advocacy groups, including the Joint Commission, have called for the implementation of standardized processes to collect and compare patient medication lists. This manuscript describes the implementation of a self-service patient kiosk intended to check in patients for a clinic appointment and collect a medication adherence history, which is then available through the electronic health record. We used business process engineering and simulation modeling to analyze existing workflow, evaluate technology impact on clinic throughput, and predict future infrastructure needs. Our empiric data indicated that a multi-function healthcare kiosk offers a feasible platform to collect medical history data. Furthermore, our simulation model showed a non-linear association between patient arrival rate, kiosk number, and estimated patient wait times. This study provides important data to help administrators and healthcare executives predict infrastructure needs when considering the use of self-service kiosks.
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.
Computer Implementation of the Bounding Surface Plasticity Model for Cohesive Soils.
1983-12-01
23 REFERENCES 1. Dafalias, Y.F., and L.R. Herrmann, "A Bounding Surface Soil Plasticity Model", Proceedings of the International Symposium of Soils...Herrmann, "Bounding Surface Formulatin of Soil Plasticity ", Chapter in Soil Mechanics - Transient and Cyclic Loads, John Wiley and Sons, Eds. O.C...Herrmann and Y.F. r)afalias, "User’s Manual for MODCAL-Bounding Surface Soil Plasticity Model Calibration and Prediction Code (Volume I)," Civil
Norman, Laura M.; Niraula, Rewati
2016-01-01
The objective of this study was to evaluate the effect of check dam infrastructure on soil and water conservation at the catchment scale using the Soil and Water Assessment Tool (SWAT). This paired watershed study includes a watershed treated with over 2000 check dams and a Control watershed which has none, in the West Turkey Creek watershed, Southeast Arizona, USA. SWAT was calibrated for streamflow using discharge documented during the summer of 2013 at the Control site. Model results depict the necessity to eliminate lateral flow from SWAT models of aridland environments, the urgency to standardize geospatial soils data, and the care for which modelers must document altering parameters when presenting findings. Performance was assessed using the percent bias (PBIAS), with values of ±2.34%. The calibrated model was then used to examine the impacts of check dams at the Treated watershed. Approximately 630 tons of sediment is estimated to be stored behind check dams in the Treated watershed over the 3-year simulation, increasing water quality for fish habitat. A minimum precipitation event of 15 mm was necessary to instigate the detachment of soil, sediments, or rock from the study area, which occurred 2% of the time. The resulting watershed model is useful as a predictive framework and decision-support tool to consider long-term impacts of restoration and potential for future restoration.
Institute of Scientific and Technical Information of China (English)
Baocang Ding; Hongguang Pan
2016-01-01
The output feedback model predictive control (MPC), for a linear parameter varying (LPV) process system including unmeasurable model parameters and disturbance (all lying in known polytopes), is considered. Some previously developed tools, including the norm-bounding technique for relaxing the disturbance-related constraint handling, the dynamic output feedback law, the notion of quadratic boundedness for specifying the closed-loop stability, and the el ipsoidal state estimation error bound for guaranteeing the recursive feasibility, are merged in the control design. Some previous approaches are shown to be the special cases. An example of continuous stirred tank reactor (CSTR) is given to show the effectiveness of the proposed approaches.
Modeling pedestrian movement at the hall of high-speed railway station during the check-in process
Tang, Tie-Qiao; Shao, Yi-Xiao; Chen, Liang
2017-02-01
With the rapid development of high speed railway (HSR), the pedestrians at HSR station have been very crowded since the demand of passengers rapidly increases. In this paper, we use a cellular automaton (CA) model to study the passengers' motion at the hall of HSR station during the check-in process. The simulation results show that the passenger's arrival rate in the hall and the service efficiency of ticket barrier have significant effects on the complex phenomena occurring in the hall, the boarding efficiency and the number of passengers in the hall during the check-in process. The simulation results can help readers to better understand the passengers' motion behaviors, the complex phenomena occurring in the hall during the check-in process, and what factors influence the boarding efficiency.
The bounded model property via step algebras and step frames
Bezhanishvili, N.; Ghilardi, S.
2014-01-01
The paper introduces semantic and algorithmic methods for establishing a variant of the analytic subformula property (called ‘the bounded proof property’, bpp) for modal propositional logics. The bpp is much weaker property than full cut-elimination, but it is nevertheless sufficient for establishin
DEFF Research Database (Denmark)
Vester, Steen
2015-01-01
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...
Reinke, Wendy M.; Lewis-Palmer, Teri; Merrell, Kenneth
2008-01-01
School-based consultation typically focuses on individual student problems and on a small number of students rather than on changing the classroom system. The Classroom Check-Up was developed as a classwide consultation model to address the need for classroom-level support while minimizing treatment integrity problems common to school-based…
Improved shape hardening function for bounding surface model for cohesive soils
Institute of Scientific and Technical Information of China (English)
Andrés Nieto-Leal; Victor N.Kaliakin
2014-01-01
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.
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.
The Distributed Network Monitoring Model with Bounded Delay Constraints
Institute of Scientific and Technical Information of China (English)
LIU Xiang-hui; YIN Jian-ping; LU Xi-cheng; CAI Zhi-ping; ZHAO Jian-min
2004-01-01
We address the problem of optimizing a distributed monitoring system and the goal of the optimization is to reduce the cost of deployment of the monitoring infrastructure by identifying a minimum aggregating set subject to delay constraint on the aggregating path. We show that this problem is NP-hard and propose approximation algorithm proving the approximation ratio with ln m+1, where is the number of monitoring nodes. At last we extend our modal with more constraint of bounded delay variation.
Directory of Open Access Journals (Sweden)
Yi Xu
2013-01-01
Full Text Available We propose a fourth-order total bounded variation regularization model which could reduce undesirable effects effectively. Based on this model, we introduce an improved split Bregman iteration algorithm to obtain the optimum solution. The convergence property of our algorithm is provided. Numerical experiments show the more excellent visual quality of the proposed model compared with the second-order total bounded variation model which is proposed by Liu and Huang (2010.
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.
Model Checking for a Class of Performance Properties of Fluid Stochastic Models
Bujorianu, L.M.; Bujorianu, M.C.; Horváth, A.; Telek, M.
2006-01-01
Recently, there is an explosive development of fluid approa- ches to computer and distributed systems. These approaches are inherently stochastic and generate continuous state space models. Usually, the performance measures for these systems are defined using probabilities of reaching certain sets o
A Monte Carlo study to check the hadronic interaction models by a new EAS hybrid experiment in Tibet
Zhang, Ying; Jiang, L; Chen, D; Ding, L K; Shibata, M; Katayose, Y; Hotta, N; Ohnishi, M; Ouchi, T; Saito, T
2013-01-01
A new EAS hybrid experiment has been designed by constructing a YAC (Yangbajing Air shower Core) detector array inside the existing Tibet-III air shower array. The first step of YAC, called "YAC-I", consists of 16 plastic scintillator units (4 rows times 4 columns) each with an area of 40 cm * 50 cm which is used to check hadronic interaction models used in AS simulations. A Monte Carlo study shows that YAC-I can record high energy electromagnetic component in the core region of air showers induced by primary particles of several tens TeV energies where the primary composition is directly measured by space experiments. It may provide a direct check of the hadronic interaction models currently used in the air shower simulations in the corresponding energy region. In present paper, the method of the observation and the sensitivity of the characteristics of the observed events to the different interaction models are discussed.
Trilinear couplings and scalar bound states in supersymmetric extensions of the standard model
Hernández, Pilar; Sanz, V
2001-01-01
The trilinear terms in minimal supersymmetric extensions of the standard model can be responsible of forming a bound state of scalars. In this talk we outline our results on the study of this bound state using a non-perturbative method, the exact renormalization group. We focus on the trilinear term between the Higgs and stop fields. (4 refs).
Safe, Multiphase Bounds Check Elimination in Java
2010-01-28
than ABCD or VDF. 8 Acknowledgements This research was supported in part by the Air Force Research Laboratory under grant F30602-02-1-0001 and the...National Science Foundation under grants CCF-0846010, EIA-0117255, CCF-0702527, and CNS-0855247. References [1] Elvira Albert, Germán Puebla , and Manuel
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.
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....
Neutralino mass bounds in the next-to-minimal supersymmetric standard model
Franke, F; Bartl, Alfred
1994-01-01
We analyze the experimental data from the search for new particles at LEP 100 and obtain mass bounds for the neutralinos of the Next--To--Minimal Supersymmetric Standard Model (NMSSM). We find that for \\tan\\beta \\gsim 5.5 a massless neutralino is still possible, while the lower mass bound for the second lightest neutralino corresponds approximately to that for the lightest neutralino in the Minimal Supersymmetric Standard Model (MSSM).
ROBUST DESIGN MODELS FOR CUSTOMER-SPECIFIED BOUNDS ON PROCESS PARAMETERS
Institute of Scientific and Technical Information of China (English)
Sangmun SHIN; Byung Rae CHO
2006-01-01
Robust design (RD) has received much attention from researchers and practitioners for years, and a number of methodologies have been studied in the research community. The majority of existing RD models focus on the minimum variability with a zero bias. However, it is often the case that the customer may specify upper bounds on one of the two process parameters (i.e., the process mean and variance). In this situation, the existing RD models may not work efficiently in incorporating the customer's needs. To this end, we propose two simple RD models using the ε-constraint feasible region method - one with an upper bound of process bias specified and the other with an upper bound on process variability specified. We then conduct a case study to analyze the effects of upper bounds on each of the process parameters in terms of optimal operating conditions and mean squarederror.
Institute of Scientific and Technical Information of China (English)
Ding Jun YAO; Rong Ming WANG
2008-01-01
The authors consider two discrete-time insurance risk models. Two moving average risk models are introduced to model the surplus process, and the probabilities of ruin are examined in models with a constant interest force. Exponential bounds for ruin probabilities of an infinite time horizon are derived by the martingale method.
Surface-bounded growth modeling applied to human mandibles
DEFF Research Database (Denmark)
Andresen, Per Rønsholt
1999-01-01
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 yield a spatially dense field. Different methods for constructing the sparse field are compared. Adaptive Gaussian smoothing is the preferred method since it is parameter free and yields good results in practice. A new method, geometry-constrained diffusion, is used to simplify The most successful...... growth model is linear and based on results from shape analysis and principal component analysis. The growth model is tested in a cross validation study with good results. The worst case mean modeling error in the cross validation study is 3.7 mm. It occurs when modeling the shape and size of a 12 years...
Cosmological bounds in MaVaN models
Energy Technology Data Exchange (ETDEWEB)
Boriero, D.F.; Holanda, P.C. de [Instituto de Fisica ' Gleb Wataghin' , Universidade Estadual de Campinas, UNICAMP, 13083-859, Campinas, Sao Paulo (Brazil)
2012-08-15
Mass varying neutrino (MaVaN) is a class of models which in cosmology try to explain the coincidence of dark energy density through a tracking mechanism related with neutrinos. This special model couples the quintessential scalar field with neutrino generating an effective mass which becomes variable. Furthermore, it has been shown that an additional coupling among the quintessential field and baryons could generate specific dependences of neutrino mass with baryonic density.
Model check of continue time Markov reward process with impulse reward%带动作回报的连续时间Markov回报过程验证
Institute of Scientific and Technical Information of China (English)
黄镇谨; 陆阳; 杨娟; 王智文
2015-01-01
为了能够更准确的表达不确定性复杂系统的时空验证,针对当前连续时间Markov回报过程( continue time markov reward decision process,CMRDP)验证中只考虑状态回报的问题,提出带动作回报的验证方法. 考虑添加了动作回报的空间性能约束,扩展现有的基于状态回报的连续时间Markov回报过程,用正则表达式表示验证属性的路径规范,扩展已有路径算子的表达能力. 给出带动作回报 CMRDP和路径规范的积模型,求解积模型在确定性策略下的诱导Markov回报模型( markov reward model,MRM) ,将CMRDP上的时空性能验证转换为MRM模型上的时空可达概率分析,并提出MRM中求解可达概率的算法. 实例分析表明,提出的验证思路和验证算法是可行的.%In order to express the verification of the uncertainty temporal and spatial properties of the complex sys-tems more accurately which include nondeterministic choices, continuous time Markov reward decision process based on state reward is extended by considering spatial properties with impulse reward and is adopted as verifica-tion model.The path formulas expressed by traditional path operator is replaced by regular expressions, which can express more comprehensive verification properties.Under deterministic schedulers, the induced Markov reward model of product model which is the product of continuous time Markov reward decision process with impulse reward and path formula is proposed.After that we reduce the problem of model checking for product model to the problem of computing the maximum time-and space-bound reachability probabilities of induced MRM and put forward a algo-rithm to solve this problem.The experiment results show that the model checking approach for CMRDP with im-pulse reward is feasible.
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.
Lucani, Daniel E; Stojanovic, Milica
2008-01-01
The goal of this paper is two-fold. First, to establish a tractable model for the underwater acoustic channel useful for network optimization in terms of convexity. Second, to propose a network coding based lower bound for transmission power in underwater acoustic networks, and compare this bound to the performance of several network layer schemes. The underwater acoustic channel is characterized by a path loss that depends strongly on transmission distance and signal frequency. The exact relationship among power, transmission band, distance and capacity for the Gaussian noise scenario is a complicated one. We provide a closed-form approximate model for 1) transmission power and 2) optimal frequency band to use, as functions of distance and capacity. The model is obtained through numerical evaluation of analytical results that take into account physical models of acoustic propagation loss and ambient noise. Network coding is applied to determine a lower bound to transmission power for a multicast scenario, fo...
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.
Chen, S.; Al-Muntasheri, G.; Abousleiman, Y. N.
2014-12-01
The critical state concept based bounding surface model is one of the most widely used elastoplastic constitutive models for geomaterials, attributed mainly to its essential feature of allowing plastic deformation to occur for stress points within the bounding surface and thus the capability to represent the realistic non-recoverable behaviour of soils and rocks observed under the cyclic loading. This paper develops an implicit integration algorithm for the bounding surface model, using the standard return mapping approach (elastic predictor-plastic corrector), to obtain the updated stresses for the given strain increments. The formulation of the constitutive integration requires the derivation of a supplementary differential equation to describe the evolution of a key variable, i.e., the ratio between the image stress and the current stress quantities. It is essentially an extension of the integration scheme presented in an earlier work used for the simple bounding surface version of modified Cam Clay associated with a substantially simplified hardening rule. The integration algorithm for the bounding surface model is implemented into the finite element analysis commercial program, ABAQUS, through the material interface of UMAT (user defined material subroutine), and then used for the analysis of wellbore stability problem. The predictions from the ABAQUS simulations are generally in excellent agreement with the available analytical solutions, thus demonstrating the accuracy and robustness of the proposed integration scheme.
Tang, Tie-Qiao; Huang, Hai-Jun; Shang, Hua-Yan
2017-02-01
In this paper, we propose a macro traffic flow model to explore the effects of the driver's bounded rationality on the evolutions of traffic waves (which include shock and rarefaction waves) and small perturbation, and on the fuel consumption and emissions (that include CO, HC and NOX) during the evolution process. The numerical results illustrate that considering the driver's bounded rationality can prominently smooth the wavefront of the traffic waves and improve the stability of traffic flow, which shows that the driver's bounded rationality has positive impacts on traffic flow; but considering the driver's bounded rationality reduces the fuel consumption and emissions only at the upstream of the rarefaction wave while enhances the fuel consumption and emissions under other situations, which shows that the driver's bounded rationality has positive impacts on the fuel consumption and emissions only at the upstream of the rarefaction wave, while negative effects on the fuel consumption and emissions under other situations. In addition, the numerical results show that the driver's bounded rationality has little prominent impact on the total fuel consumption, and emissions during the whole evolution of small perturbation.
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 $2\\sigma$.
Widths of K¯-nuclear deeply bound states in a dynamical model
Mareš, J.; Friedman, E.; Gal, A.
2005-01-01
The relativistic mean field (RMF) model is applied to a system of nucleons and a Kbar meson, interacting via scalar and vector boson fields. The model incorporates the standard RMF phenomenology for bound nucleons and, for the Kbar meson, it relates to low-energy Kbar N and K- atom phenomenology. Deeply bound Kbar nuclear states are generated dynamically across the periodic table and are exhibited for 12C and 16O over a wide range of binding energies. Substantial polarization of the core nucleus is found for these light nuclei. Absorption modes are also included dynamically, considering explicitly both the resulting compressed nuclear density and the reduced phase space for Kbar absorption from deeply bound states. The behavior of the calculated width as function of the Kbar binding energy is studied in order to explore limits on the possible existence of narrow Kbar nuclear states.
Higgs mass bounds from renormalization flow for a Higgs-top-bottom model
Energy Technology Data Exchange (ETDEWEB)
Gies, Holger; Sondenheimer, Rene [Friedrich-Schiller-Universitaet Jena, Theoretisch-Physikalisches Institut, Jena (Germany)
2015-02-01
We study a chiral Yukawa model mimicking the Higgs-top-bottom sector of the standard model. We reanalyze the conventional arguments that relate a lower bound for the Higgs mass with vacuum stability in the light of exact results for the regularized fermion determinant as well as in the framework of the functional renormalization group. In both cases, we find no indication for vacuum instability nor meta-stability induced by top fluctuations if the cutoff is kept finite but arbitrary. A lower bound for the Higgs mass arises for the class of standard bare potentials of φ{sup 4} type from the requirement of a well-defined functional integral (i.e., stability of the bare potential). This consistency bound can, however, be relaxed considerably by more general forms of the bare potential without necessarily introducing new metastable minima. (orig.)
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.
Fox, Zachary; Neuert, Gregor; Munsky, Brian
2016-08-01
Emerging techniques now allow for precise quantification of distributions of biological molecules in single cells. These rapidly advancing experimental methods have created a need for more rigorous and efficient modeling tools. Here, we derive new bounds on the likelihood that observations of single-cell, single-molecule responses come from a discrete stochastic model, posed in the form of the chemical master equation. These strict upper and lower bounds are based on a finite state projection approach, and they converge monotonically to the exact likelihood value. These bounds allow one to discriminate rigorously between models and with a minimum level of computational effort. In practice, these bounds can be incorporated into stochastic model identification and parameter inference routines, which improve the accuracy and efficiency of endeavors to analyze and predict single-cell behavior. We demonstrate the applicability of our approach using simulated data for three example models as well as for experimental measurements of a time-varying stochastic transcriptional response in yeast.
A method for model checking UML statecharts%一种UML状态图模型检测方法
Institute of Scientific and Technical Information of China (English)
张涛; 黄少滨; 黄宏涛; 吕天阳; 刘刚
2011-01-01
The aim of this paper is to find various errors and inconsistencies of system design in the early stages of the development process. A method for model checking UML statecharts was proposed, and was used to verify the consistency of the design model and the requirement specifications. The elements of UML statecharts were defined by a tuple system, and the middle representation of the UML statecharts - SC - was given. Based on the definition of operational semantics of SC, the statechart was converted into a state transition system with KRIPKE semantics, and the property which the system must meet was expressed as a linear temporal logic formula. Finally, a model checking method was given to verify whether the state transition system could meet the conditions of the linear temporal logic formula. This method can convert more elements of statecharts, it can also reduce the state space of transition system of statecharts and improve the efficiency of the model checking.%为在开发过程早期发现系统设计的各种错误与不一致,提出一种UML状态图模型检测方法,用于验证设计模型与需求规约间的一致性.该方法通过元组定义UML状态图的主要元素,给出状态图的中间表示形式SC.基于SC上定义的操作语义,该方法将状态图转换为具有KRIPKE语义结构的状态迁移系统,并将系统需满足的性质表示为线性时序逻辑公式,用模型检测技术验证状态迁移系统对线性时序逻辑公式的满足性.该方法可以转换更多的状态图元素,缩减状态图迁移系统的状态空间及提高模型检测效率.
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.
Towards automated software model checking using graph transformation systems and Bogor
Institute of Scientific and Technical Information of China (English)
Vahid RAFE; Adel T.RAHMANI
2009-01-01
Graph transformation systems have become a general formal modeling language to describe many models in software development process. Behavioral modeling of dynamic systems and model-to-model transformations are only a few examples in which graphs have been used to software development. But even the perfect graph transformation system must be equipped with automated analysis capabilities to let users understand whether such a formal specification fulfills their requirements. In this paper,we present a new solution to verify graph transformation systems using the Bogor model checker. The attributed graph grammars (AGG)-Iike graph transformation systems are translated to Bandera intermediate representation (BIR), the input language of Bogor,and Bogor verifies the model against some interesting properties defined by combining linear temporal logic (LTL) and special-purpose graph rules. Experimental results are encouraging, showing that in most cases oar solution improves existing approaches in terms of both performance and expressiveness.
DEFF Research Database (Denmark)
Odgaard, Peter Fogh; Stoustrup, Jakob; Mataji, B.
2007-01-01
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 of th...... 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. ......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...... 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...
Boundedly rational learning and heterogeneous trading strategies with hybrid neuro-fuzzy models
S.D. Bekiros
2009-01-01
The present study deals with heterogeneous learning rules in speculative markets where heuristic strategies reflect the rules-of-thumb of boundedly rational investors. The major challenge for "chartists" is the development of new models that would enhance forecasting ability particularly for time se
Using Abstraction and Model Checking to Detect Safety Violations in Requirements Specifications
1998-11-01
into a corresponding scenario in the original state machine model 6.4 Combining Automatic Abstraction Methods with Other Methods After automatic...abstraction methods, such as those de- scribed above, are used to produce a reduced state machine model , other abstraction methods, such as those described...generation of invari- ants [46], may further reduce the state space. Moreover, once the specification of the state machine model has been reduced
Coexistence of bounded and unbounded motions in a bouncing ball model
Marò, Stefano
2013-05-01
We consider the model describing the vertical motion of a ball falling with constant acceleration on a wall and elastically reflected. The wall is supposed to move in the vertical direction according to a given periodic function f. We apply the Aubry-Mather theory to the generating function in order to prove the existence of bounded motions with prescribed mean time between the bounces. As the existence of unbounded motions is known, it is possible to find a class of functions f that allow both bounded and unbounded motions.
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...
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...
Who is pointing when to whom: on model-checking pointer structures
Distefano, Dino; Rensink, Arend; Katoen, Joost-Pieter
2003-01-01
This paper introduces a new model to reason about systems composed by entities that can refer to each other via pointers, such as objects in an object-based system. The model, based on History-Dependent Automata, treats particular cases of unboundedness by a special layered mechanism of abstraction.
Evolution Track of Outward Bound Model and Its Contemporary Enlightenment%Outward Bound 模式的演变轨迹与当代启示
Institute of Scientific and Technical Information of China (English)
王海波
2013-01-01
In order to explore the adaptation of the outward bound model of China's national conditions, four models of foreign outward bound's evolution track were examined since the 1940s.Based on the show of fea-tures different models, the analysis of different models of "common"and"inadequate", drawing the success-ful approach, summarized their inspiration ideas , it will help China promote building process of "localization"outward bound model, thus contributing to the overall development of China's outward bound.% 为了探寻适应我国国情的拓展训练模式，审视了20世纪40年代以来国外拓展训练四种模式的演化轨迹，在呈现出不同模式特点的基础上，分析不同模式的“共性”与“不足”，借鉴其成功方法，归纳其启示思路，将有利于推进我国“本土化”拓展训练模式的构建进程，进而促进我国拓展训练的全面发展。
... Checked Print This Topic En español Get Your Cholesterol Checked Browse Sections The Basics Overview Cholesterol Test ... How often do I need to get my cholesterol checked? The general recommendation is to get your ...
A Rough Set Bounded Spatially Constrained Asymmetric Gaussian Mixture Model for Image Segmentation.
Ji, Zexuan; Huang, Yubo; Sun, Quansen; Cao, Guo; Zheng, Yuhui
2017-01-01
Accurate image segmentation is an important issue in image processing, where Gaussian mixture models play an important part and have been proven effective. However, most Gaussian mixture model (GMM) based methods suffer from one or more limitations, such as limited noise robustness, over-smoothness for segmentations, and lack of flexibility to fit data. In order to address these issues, in this paper, we propose a rough set bounded asymmetric Gaussian mixture model with spatial constraint for image segmentation. First, based on our previous work where each cluster is characterized by three automatically determined rough-fuzzy regions, we partition the target image into three rough regions with two adaptively computed thresholds. Second, a new bounded indicator function is proposed to determine the bounded support regions of the observed data. The bounded indicator and posterior probability of a pixel that belongs to each sub-region is estimated with respect to the rough region where the pixel lies. Third, to further reduce over-smoothness for segmentations, two novel prior factors are proposed that incorporate the spatial information among neighborhood pixels, which are constructed based on the prior and posterior probabilities of the within- and between-clusters, and considers the spatial direction. We compare our algorithm to state-of-the-art segmentation approaches in both synthetic and real images to demonstrate the superior performance of the proposed algorithm.
Reinke, Wendy M; Lewis-Palmer, Teri; Merrell, Kenneth
2008-01-01
School-based consultation typically focuses on individual student problems and on a small number of students rather than on changing the classroom system. The Classroom Check-up (CCU) was developed as a classwide consultation model to address the need for classroom level support while minimizing treatment integrity problems common to school-based consultation. The purpose of the study was to evaluate the effects of the CCU and Visual Performance Feedback on teacher and student behavior. Results indicated that implementation of the CCU plus Visual Performance Feedback increased teacher implementation of classroom management strategies, including increased use of praise, use of behavior specific praise, and decreased use of reprimands. Further, these changes in teacher behavior contributed to decreases in classroom disruptive behavior. The results are encouraging because they suggest that consultation at the classroom level can create meaningful teacher and student behavior change.
Stochastic Model Checking Continuous Time Markov Process%随机模型检测连续时间Markov过程
Institute of Scientific and Technical Information of China (English)
钮俊; 曾国荪; 吕新荣; 徐畅
2011-01-01
The trustworthiness of a dynamic system includes the correctness of function and the satisfiability of per formance mainly. This paper proposed an approach to verify the function and performance of a system under considera tion integratedly. Continuous-time Markov decision process (CTMDP) is a model that contains some aspects such as probabilistic choice;stochastic timing and nondeterminacy; and it is the model by which we verify function properties and analyze performance properties uniformly. We can verify the functional and performance specifications by computing the reachability probabilities in the product CTMDP. We proved the correctness of our approach; and obtained our veri fication results by using model checker MRMC(Markov Reward Model Checker). The theoretical results show that model checking CTMDP model is necessary and the model checking approach is feasible.%功能正确和性能可满足是复杂系统可信要求非常重要的两个方面.从定性验证和定量分析相结合的角度,对复杂并发系统进行功能验证和性能分析,统一地评估系统是否可信.连续时间Markov决策过程CTMDP(Continuous-time Markov decision process)能够统一刻画复杂系统的概率选择、随机时间及不确定性等重要特征.提出用CTMDP作为系统定性验证和定量分析模型,将复杂系统的功能验证和性能分析转化为CTMDP中的可达概率求解,并证明验证过程的正确性,最终借助模型检测器MRMC(Markov Reward Model Checker)实现模型检测.理论分析表明,提出的针对CTMDP模型的验证需求是必要的,验证思路和方法具有可行性.
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.
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.
Upper Bounds on the Degeneracy of the Ground State in Quantum Field Models
Directory of Open Access Journals (Sweden)
Asao Arai
2016-01-01
Full Text Available Axiomatic abstract formulations are presented to derive upper bounds on the degeneracy of the ground state in quantum field models including massless ones. In particular, given is a sufficient condition under which the degeneracy of the ground state of the perturbed Hamiltonian is less than or equal to the degeneracy of the ground state of the unperturbed one. Applications of the abstract theory to models in quantum field theory are outlined.
Scattering resonances and two-particle bound states of the extended Hubbard model
Energy Technology Data Exchange (ETDEWEB)
Valiente, M; Petrosyan, D [Institute of Electronic Structure and Laser, FORTH, 71110 Heraklion, Crete (Greece)
2009-06-28
We present a complete derivation of two-particle states of the one-dimensional extended Bose-Hubbard model involving attractive or repulsive on-site and nearest-neighbour interactions. We find that this system possesses scattering resonances and two families of energy-dependent interaction-bound states which are not present in the Hubbard model with the on-site interaction alone. (fast track communication)
Can We Efficiently Check Concurrent Programs Under Relaxed Memory Models in Maude?
DEFF Research Database (Denmark)
Arrahman, Yehia Abd; Andric, Marina; Beggiato, Alessandro;
2014-01-01
to the state space explosion. Several techniques have been proposed to mitigate those problems so to make verification under relaxed memory models feasible. We discuss how to adopt some of those techniques in a Maude-based approach to language prototyping, and suggest the use of other techniques that have been......Relaxed memory models offer suitable abstractions of the actual optimizations offered by multi-core architectures and by compilers of concurrent programming languages. Using such abstractions for verification purposes is challenging in part due to their inherent non-determinism which contributes...
Institute of Scientific and Technical Information of China (English)
Chun-Zheng CAO; Jin-Guan LIN
2012-01-01
The aim of this paper is to study the tests for variance heterogeneity and/or autocorrelation in nonlinear regression models with elliptical and AR(1) errors.The elliptical class includes several symmetric multivariate distributions such as normal,Student-t,power exponential,among others.Several diagnostic tests using score statistics and their adjustment are constructed.The asymptotic properties,including asymptotic chi-square and approximate powers under local alternatives of the score statistics,are studied.The properties of test statistics are investigated through Monte Carlo simulations.A data set previously analyzed under normal errors is reanalyzed under elliptical models to illustrate our test methods.
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,
Providing evidence of likely being on time – Counterexample generation for CTMC model checking
Han, T.; Katoen, J.P.; Namjoshi, K.; Yoneda, T.; Higashino, T.; Okamura, Y.
2007-01-01
Probabilistic model checkers typically provide a list of individual state probabilities on the refutation of a temporal logic formula. For large state spaces, this information is far too detailed to act as useful diagnostic feedback. For quantitative (constrained) reachability problems, sets of path
Learning and Model-checking Networks of I/O Automata
DEFF Research Database (Denmark)
Mao, Hua; Jaeger, Manfred
2012-01-01
We introduce a new statistical relational learning (SRL) approach in which models for structured data, especially network data, are constructed as networks of communicating nite probabilistic automata. Leveraging existing automata learning methods from the area of grammatical inference, we can le...
Bicudo, P.; Cardoso, M.
2016-11-01
We address q q Q ¯Q ¯ exotic tetraquark bound states and resonances with a fully unitarized and microscopic quark model. We propose a triple string flip-flop potential, inspired by lattice QCD tetraquark static potentials and flux tubes, combining meson-meson and double Y potentials. Our model includes the color excited potential, but neglects the spin-tensor potentials, as well as all the other relativistic effects. To search for bound states and resonances, we first solve the two-body mesonic problem. Then we develop fully unitary techniques to address the four-body tetraquark problem. We fold the four-body Schrödinger equation with the mesonic wave functions, transforming it into a two-body meson-meson problem with nonlocal potentials. We find bound states for some quark masses, including the one reported in lattice QCD. Moreover, we also find resonances and calculate their masses and widths, by computing the T matrix and finding its pole positions in the complex energy plane, for some quantum numbers. However, a detailed analysis of the quantum numbers where binding exists shows a discrepancy with recent lattice QCD results for the l l b ¯ b ¯ tetraquark bound states. We conclude that the string flip-flop models need further improvement.
Directory of Open Access Journals (Sweden)
Wanda Vrasti
2012-03-01
Full Text Available Over the past couple of months history has been unfolding with dizzying speed. The #occupy model of leaderless, demandless direct action, which in the beginning no one with only a slim understanding of how capitalism works thought could become anything more than a facile if charming jab at anti-corporate activism, has gone viral. Every morning we wake up to new reports about ‘occupying X’, where X can be anything from cities, campuses, boardrooms, buildings, highways, and public events, all the way to academic disciplines. What originally seemed like a romantic fantasy about temporary autonomous zones now feels like history. And no one likes to find themselves on thewrong side of history, especially not intellectuals, let alone intellectuals in the business of explaining global politics.
On decidability and model checking for a first order modal logic for value-passing processes
Institute of Scientific and Technical Information of China (English)
薛锐; 林惠民
2003-01-01
A semantic interpretation of a first order extension of Hennessy-Milner logic for value-passing processes, named HML(FO), is presented. The semantics is based on symbolic transitiongraphs with assignment. It is shown that the satisfiability of the two-variable sub-logic HML(FO2) ofHML(FO) is decidable, and the complexity discussed. Finally, a decision procedure for model checkingthe value-passing processes with respect to HML(FO2) is obtained.
Rigorous bounds on aerosol optical properties from measurement and/or model constraints
McGraw, Robert; Fierce, Laura
2016-04-01
Sparse-particle aerosol models are an attractive alternative to sectional and modal methods for representation of complex, generally mixed particle populations. In the quadrature method of moments (QMOM) a small set of abscissas and weights, determined from distributional moments, provides the sparse set. Linear programming (LP) yields a generalization of the QMOM that is especially convenient for sparse particle selection. In this paper we use LP to obtain rigorous, nested upper and lower bounds to aerosol optical properties in terms of a prescribed Bayesian-like sequence of model or simulated measurement constraints. Examples of such constraints include remotely-sensed light extinction at different wavelengths, modeled particulate mass, etc. Successive reduction in bound separation with each added constraint provides a quantitative measure of its contextual information content. The present study is focused on univariate populations as a first step towards development of new simulation algorithms for tracking the physical and optical properties of multivariate particle populations.
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
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.
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) ...
Bound states in a model of interaction of Dirac field with material plane
Directory of Open Access Journals (Sweden)
Pismak Yu. M.
2016-01-01
Full Text Available In the framework of the Symanzik approach model of the interaction of the Dirac spinor field with the material plane in the 3 + 1-dimensional space is constructed. The model contains eight real parameters characterizing the properties of the material plane. The general solution of the Euler-Lagrange equations of the model and dispersion equations for bound states are analyzed. It is shown that there is a choice of parameters of the model in which the connected states are characterized by dispersion law of a mass-less particle moving along the material plane with the dimensionless Fermi velocity not exceeding one.
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....
A Check on the Cardassian Expansion Model with Type-Ia Supernovae Data
Institute of Scientific and Technical Information of China (English)
Li Cao
2003-01-01
We use the magnitude-redshift relation for the type Ia supernova datacompiled by Riess et al. to analyze the Cardassian expansion scenario. This sce-nario assumes the universe to be fiat, matter dominated, and accelerating, butcontains no vacuum contribution. The best fitting model parameters are Ho =65.3kms-1 Mpc-1, n = 0.35 and Ωm = 0.05. When the highest redshift supernova,SN 1997ck, is excluded, Ho remains the same, but n becomes 0.20 and Ωm, 0.15, andthe matter density remains unreasonably low. Our result shows that this particularscenario is strongly disfavoured by the SNeIa data.
Quintana, César; Ramos, Gonzalo; Moral, Andoni; Rodriguez, Jose Antonio; Pérez, Carlos; Hutchinson, Ian; INGLEY, Richard; Rull, Fernando
2016-10-01
Raman Laser Spectrometer (RLS) is one of the Pasteur payload instruments located at the Rover of the ExoMars mission and within the ESA's Aurora Exploration Programme. RLS will explore the Mars surface composition through the Raman spectroscopy technique. The instrument is divided into several units: a laser for Raman emission stimulation, an internal optical head (iOH) for sample excitation and for Raman emission recovering, a spectrometer with a CCD located at its output (SPU), the optical harness (OH) for the units connection, from the laser to the excitation path of the iOH and from the iOH reception path to the spectrometer, and the corresponding electronics for the CCD operation.Due to the variability of the samples to be analyzed on Mars, a radiometry prediction for the instrument performance results to be of the critical importance. In such a framework, and taking into account the SNR (signal to noise ratio) required for the achievement of successful results from the scientific point of view (a proper information about the Mars surface composition), a radiometric model has been developed to provide the requirements for the different units, i.e. the laser irradiance, the iOH, OH, and SPU throughputs, and the samples that will be possible to be analyzed in terms of its Raman emission and the relationship of the Raman signal with respect to fluorescence emission, among others.The radiometric model fundamentals (calculations and approximations), as well as the first results obtained during the bread board characterization campaign are here reported on.
Automating checks of plan check automation.
Halabi, Tarek; Lu, Hsiao-Ming
2014-07-08
While a few physicists have designed new plan check automation solutions for their clinics, fewer, if any, managed to adapt existing solutions. As complex and varied as the systems they check, these programs must gain the full confidence of those who would run them on countless patient plans. The present automation effort, planCheck, therefore focuses on versatility and ease of implementation and verification. To demonstrate this, we apply planCheck to proton gantry, stereotactic proton gantry, stereotactic proton fixed beam (STAR), and IMRT treatments.
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...
The craft of model making: PSPACE bounds for non-iterative modal logics
Schröder, Lutz
2008-01-01
For lack of general algorithmic methods that apply to wide classes of logics, establishing a complexity bound for a given modal logic is often a laborious task. The present work is a step towards a general theory of the complexity of modal logics. Our main result is that all rank-1 logics enjoy a shallow model property and thus are, under mild assumptions on the format of their axiomatisation, in PSPACE. This leads to a unified derivation of tight PSPACE-bounds for a number of logics including K, KD, coalition logic, graded modal logic, majority logic, and probabilistic modal logic. Our generic algorithm moreover finds tableau proofs that witness pleasant proof-theoretic properties including a weak subformula property. This generality is made possible by a coalgebraic semantics, which conveniently abstracts from the details of a given model class and thus allows covering a broad range of logics in a uniform way.
Towards a model of large scale dynamics in transitional wall-bounded flows
Manneville, Paul
2015-01-01
A system of simplified equations is proposed to govern the feedback interactions of large-scale flows present in laminar-turbulent patterns of transitional wall-bounded flows, with small-scale Reynolds stresses generated by the self-sustainment process of turbulence itself modeled using an extension of Waleffe's approach (Phys. Fluids 9 (1997) 883-900), the detailed expression of which is displayed as an annex to the main text.
Optimization in modeling the ribs-bounded contour from computer tomography scan
Bilinskas, M. J.; Dzemyda, G.
2016-10-01
In this paper a method for analyzing transversal plane images from computer tomography scans is presented. A mathematical model that describes the ribs-bounded contour was created and the problem of approximation is solved by finding out the optimal parameters of the model in the least-squares sense. Such model would be useful in registration of images independently on the patient position on the bed and on the radio-contrast agent injection. We consider the slices, where ribs are visible, because many important internal organs are located here: liver, heart, stomach, pancreas, lung, etc.
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.
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.
Modeling of Wall-Bounded Complex Flows and Free Shear Flows
Shih, Tsan-Hsing; Zhu, Jiang; Lumley, John L.
1994-01-01
Various wall-bounded flows with complex geometries and free shear flows have been studied with a newly developed realizable Reynolds stress algebraic equation model. The model development is based on the invariant theory in continuum mechanics. This theory enables us to formulate a general constitutive relation for the Reynolds stresses. Pope was the first to introduce this kind of constitutive relation to turbulence modeling. In our study, realizability is imposed on the truncated constitutive relation to determine the coefficients so that, unlike the standard k-E eddy viscosity model, the present model will not produce negative normal stresses in any situations of rapid distortion. The calculations based on the present model have shown an encouraging success in modeling complex turbulent flows.
Schneider, F.
1999-01-01
UML use cases conceptually identify function points or major requirements that a software system must satisfy. Sequence diagrams expand each use case to show in temporal sequence a more detailed notion of intended system behavior.
Fosco, Gregory M; Van Ryzin, Mark; Stormshak, Elizabeth A; Dishion, Thomas J
2014-05-01
This study examined contextual factors (caregiver depression, family resources, ethnicity, and initial levels of youth problem behavior) related to the effectiveness of the Family Check-Up (FCU) and evaluated family processes as a mediator of FCU intervention response and adolescent antisocial behavior. We followed a sample of 180 ethnically diverse youths of families who engaged in the FCU intervention. Family data were collected as part of the FCU assessment, and youth data were collected over 4 years, from sixth through ninth grade. Findings indicated that caregiver depression and minority status predicted greater caregiver motivation to change. In turn, caregiver motivation was the only direct predictor of FCU intervention response during a 1-year period. Growth in family conflict from sixth through eighth grade mediated the link between FCU response and ninth-grade antisocial behavior. This study explicitly tested core aspects of the FCU intervention model and demonstrated that caregiver motivation is a central factor that underlies family response to the FCU. The study also provided support for continued examination of family process mechanisms that account for enduring effects of the FCU and other family-centered interventions.
Energy Technology Data Exchange (ETDEWEB)
Dowding, Kevin J.; Hills, Richard Guy (New Mexico State University, Las Cruces, NM)
2005-04-01
Numerical models of complex phenomena often contain approximations due to our inability to fully model the underlying physics, the excessive computational resources required to fully resolve the physics, the need to calibrate constitutive models, or in some cases, our ability to only bound behavior. Here we illustrate the relationship between approximation, calibration, extrapolation, and model validation through a series of examples that use the linear transient convective/dispersion equation to represent the nonlinear behavior of Burgers equation. While the use of these models represents a simplification relative to the types of systems we normally address in engineering and science, the present examples do support the tutorial nature of this document without obscuring the basic issues presented with unnecessarily complex models.
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.
NN S-Wave Elastic Cross Section and Possible Bound States in a Constituent Quark Model
Institute of Scientific and Technical Information of China (English)
PANG Hou-Rong; PING Jia-Lun; WANG Fan
2008-01-01
In the framework of a chiral constituent quark model, considering the contributions of π annihilation and one-gluon annihilation, the proton-antiproton s-wave elastic scattering cross section experimental data can be reproduced by adjusting properly one-gluon annihilation coupling constant. After fixing the model parameters, we perform a dynamical calculation for all possible s-wave nucleon-antinucleon states. The results show that there is no s-wave bound state as indicated by a strong enhancement at threshold of pp in J/ψ and B decay.
A Density Matrix Renormalization Group Approach to an Asymptotically Free Model with Bound States
Martín-Delgado, M A
1999-01-01
We apply the DMRG method to the 2 dimensional delta function potential which is a simple quantum mechanical model with asymptotic freedom and formation of bound states. The system block and the environment block of the DMRG contain the low energy and high energy degrees of freedom, respectively. The ground state energy and the lowest excited states are obtained with an unprecedent accuracy. We compare the DMRG method with the Similarity RG method and propose its generalization to field theoretical models in high energy physics.
Directory of Open Access Journals (Sweden)
Ueno Kazuko
2009-04-01
Full Text Available Abstract Background Model checking approaches were applied to biological pathway validations around 2003. Recently, Fisher et al. have proved the importance of model checking approach by inferring new regulation of signaling crosstalk in C. elegans and confirming the regulation with biological experiments. They took a discrete and state-based approach to explore all possible states of the system underlying vulval precursor cell (VPC fate specification for desired properties. However, since both discrete and continuous features appear to be an indispensable part of biological processes, it is more appropriate to use quantitative models to capture the dynamics of biological systems. Our key motivation of this paper is to establish a quantitative methodology to model and analyze in silico models incorporating the use of model checking approach. Results A novel method of modeling and simulating biological systems with the use of model checking approach is proposed based on hybrid functional Petri net with extension (HFPNe as the framework dealing with both discrete and continuous events. Firstly, we construct a quantitative VPC fate model with 1761 components by using HFPNe. Secondly, we employ two major biological fate determination rules – Rule I and Rule II – to VPC fate model. We then conduct 10,000 simulations for each of 48 sets of different genotypes, investigate variations of cell fate patterns under each genotype, and validate the two rules by comparing three simulation targets consisting of fate patterns obtained from in silico and in vivo experiments. In particular, an evaluation was successfully done by using our VPC fate model to investigate one target derived from biological experiments involving hybrid lineage observations. However, the understandings of hybrid lineages are hard to make on a discrete model because the hybrid lineage occurs when the system comes close to certain thresholds as discussed by Sternberg and Horvitz in
Decay of Bethe-Salpeter kernel and bound states for the lattice four Fermi model
Energy Technology Data Exchange (ETDEWEB)
Anjos, Petrus Henrique Ribeiro dos [Universidade Federal de Goias (UFG), Goiania, GO (Brazil)
2012-07-01
Full text: We consider an imaginary-time functional integral formulation of the the lattice four-Fermi or Gross-Neveu model in d + 1 space-time dimensions (d = 1, 2, 3) and with N-component fermions. Let 0 < {kappa} << 1 be the hopping parameter, {lambda} > 0 the four-fermion coupling, m > 0 the bare fermion mass and take s x s spin matrices (s = 2,4). In a previous work, we derive spectral representations for two- and four- point correlation functions and use this result to show that the low-lying energy-momentum spectrum of this model exhibits isolated dispersion curves which are identified as single particles, multi-particle bands and bound states. In this previous analysis, the one-particle energy-momentum spectrum is obtained rigorously and is manifested by sN/2 isolated and identical dispersion curves, and the mass of particles has asymptotic value order of order 1n {kappa}. The existence of two-particle bound states above or below the two-particle band depends on whether Gaussian domination does hold or does not, respectively. Two-particle bound states emerge from solutions to a lattice Bethe-Salpeter equation that we solve in a ladder approximation. Within this approximation, the bound states have O({kappa}{sup 0}) binding energies at zero system momentum and their masses are all equal, with value {approx} -2 1n {kappa}. In this work, using the hyperplane decoupling method, we provide a detailed analysis of the decay of the Bethe-Salpeter kernel and show how to use this decay to extend the spectral result obtained in the ladder approximation to the full model. In particular, we prove that if the two-point function decays faster than the four-point function (Gaussian subjugation) then the only point in the mass spectrum above the one-particle mass and below the two-particle band is the bound state mass. (author)
Modeling the vertical motion of drops bouncing on a bounded fluid reservoir
Blanchette, François
2016-03-01
We present a first-principles model of drops bouncing on a liquid reservoir. We consider a nearly inviscid liquid reservoir and track the waves that develop in a bounded domain. Bouncing drops are modeled as vertical linear springs. We obtain an expression for the contact force between drop and liquid surface and a model where the only adjustable parameter is an effective viscosity used to describe the waves on the reservoir's surface. With no adjustable parameters associated to the drop, we recover experimental bouncing times and restitution coefficients. We use our model to describe the effect of the Bond, Ohnesorge, and Weber numbers on drops bouncing on a stationary reservoir. We also use our model to describe drops bouncing on an oscillated reservoir, describing various bouncing modes and a walking threshold.
Dennatale, J. S.; Herrmann, L. R.; Defalias, Y. F.
1983-02-01
In order to reduce the complexity of the model calibration process, a computer-aided automated procedure has been developed and tested. The computer code employs a Quasi-Newton optimization strategy to locate that set of parameter values which minimizes the discrepancy between the model predictions and the experimental observations included in the calibration data base. Through application to a number of real soils, the automated procedure has been found to be an efficient, reliable and economical means of accomplishing model calibration. Although the code was developed specifically for use with the Bounding Surface plasticity model, it can readily be adapted to other constitutive formulations. Since the code greatly reduces the dependence of calibration success on user expertise, it significantly increases the accessibility and usefulness of sophisticated material models to the general engineering community.
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.
Meson-meson bound states in a (2+1)-dimensional strongly coupled lattice QCD model
Faria da Veiga, Paulo A.; O'Carroll, Michael; Neto, Antônio Francisco
2004-05-01
We consider bound states of two mesons (antimesons) in lattice quantum chromodynamics in an Euclidean formulation. For simplicity, we analyze an SU(3) theory with a single flavor in 2+1 dimensions and two-dimensional Dirac matrices. For a small hopping parameter κ and small plaquette coupling g-20, such that 0
Improved Model Checking Technology for Program Temporal Safety Properties%改进的程序时序安全属性模型检测技术
Institute of Scientific and Technical Information of China (English)
张志; 张林; 曾庆凯
2011-01-01
This paper presents two points of improvements for model checking temporal safety properties of program: more efficient model checking algorithm is proposed, which can simplify the checking process and reduce the time cost by extending the state machine model with each function.Alias analysis is used to determine the dataflow dependency between safety operations, which makes the checking process more accurate.Experimental results show that the method can work more efficiently and exactly.%针对程序时序安全属性模型栓测技术改进模型检测算法,使安全漏洞状态机以函数为单位进行扩展,简化程序模型检测过程,以提高检测效率.存检测过程中加入别名分析,考虑安全操作之间的数据流依赖关系,以提高检测的准确性.实验结果表明,改进后的方法比原检测方法具有更高的效率和准确性.
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.
Mass spectrum and bounds on the couplings in Yukawa models with mirror-fermions
Energy Technology Data Exchange (ETDEWEB)
Lin, L.; Muenster, G.; Plagge, M. [Muenster Univ. (Germany). Inst. fuer Theoretische Physik 1; Montvay, I.; Wittig, H. [Deutsches Elektronen-Synchrotron, DESY, Hamburg (Germany); Frick, C.; Trappenberg, T. [HLRZ, Juelich (Germany)
1992-12-01
The SU(2){sub L}xSU(2){sub R} symmetric Yukawa model with mirror-fermions in the limit where the mirror-fermion is decoupled is studied both analytically and numerically. The bare scalar self-coupling {lambda} is fixed at zero and infinity. The phase structure is explored and the relevant phase transition is found to be consistent with a second order one. The fermionic mass spectrum close to that transition is discussed and a first non-perturbative estimate of the influence of fermions on the upper and lower bounds on the renormalized scalar self-coupling is given. Numerical results are confronted with perturbative predictions. (orig.).
Mass Spectrum and Bounds on the Couplings in Yukawa Models With Mirror-Fermions
Lin, L; Plagge, M; Montvay, István; Wittig, H; Frick, C; Trappenberg, T
1993-01-01
The $\\rm SU(2)_L\\otimes SU(2)_R$ symmetric Yukawa model with mirror-fermions in the limit where the mirror-fermion is decoupled is studied both analytically and numerically. The bare scalar self-coupling $\\lambda$ is fixed at zero and infinity. The phase structure is explored and the relevant phase transition is found to be consistent with a second order one. The fermionic mass spectrum close to that transition is discussed and a first non-perturbative estimate of the influence of fermions on the upper and lower bounds on the renormalized scalar self-coupling is given. Numerical results are confronted with perturbative predictions.
Mass spectrum and bounds on the couplings in Yukawa models with mirror-fermions
Energy Technology Data Exchange (ETDEWEB)
Lin, L. (Inst. f. Theor. Physik I, Univ. Muenster (Germany)); Muenster, G. (Inst. f. Theor. Physik I, Univ. Muenster (Germany)); Plagge, M. (Inst. f. Theor. Physik I, Univ. Muenster (Germany)); Montvay, I. (Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany)); Wittig, H. (Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany)); Frick, C. (HLRZ, Juelich (Germany)); Trappenberg, T. (HLRZ, Juelich (Germany))
1993-03-01
The SU(2)[sub L] x SU(2)[sub R] symmetric Yukawa model with mirror-fermions in the limit where the mirror-fermion is decoupled is studied both analytically and numerically. The bare scalar self-coupling [lambda] is fixed at zero and infinity. The phase structure is explored and the relevant phase transition is found to be consistent with a second order one. The fermionic mass spectrum close to that transition is discussed and a first non-perturbative estimate of the influence of fermions on the upper and lower bounds on the renormalized scalar self-coupling is given. Numerical results are confronted with perturbative predictions. (orig.)
A Lower Bound on the Entanglement in the Jaynes-Cummings Model
Institute of Scientific and Technical Information of China (English)
CAI Jin-Fang; ZOU Jian
2005-01-01
@@ The entanglement between an atom and field is investigated by using the Jaynes-Cummings model. The initial atomic state is supposed in a mixed state and the field is in a squeezed state. The lower bound on the entanglement quantified by concurrence is calculated. It is found that the entanglement with the atom being initially in a mixed state can be larger than that with the atom being initially in a pure state. The entanglement is not a monotone function of the squeezing parameter r of the field and it achieves the maximum for certain r and then decreases with further increase of r.
A Branch and Bound Algorithm for the Protein Folding Problem in the HP Lattice Model
Institute of Scientific and Technical Information of China (English)
Mao Chen; Wen-Qi Huang
2005-01-01
A branch and bound algorithm is proposed for the two-dimensional protein folding problem in the HP lattice model. In this algorithm, the benefit of each possible location of hydrophobic monomers is evaluated and only promising nodes are kept for further branching at each level. The proposed algorithm is compared with other well-known methods for 10 benchmark sequences with lengths ranging from 20 to 100 monomers. The results indicate that our method is a very efficient and promising tool for the protein folding problem.
Charged Higgs mass bound from the b --> s$\\gamma$ process in the minimal supergravity model
Goto, T; Goto, Toru; Okada, Yasuhiro
1994-01-01
We study the constraint on the mass of the charged Higgs boson in the minimal supergravity model based on the recent measurement of the inclusive b\\rightarrow s\\gamma decay. It is shown that the lower bound for the charged Higgs mass crucially depends on the sign of the higgsino mass parameter (\\mu). For \\mu0 due to cancellations between charged Higgs and supersymmetric particle contributions. For 3\\lsim\\tan\\beta\\lsim5, a charged Higgs lighter than 180 GeV is excluded by this process irrespective of the sign of \\mu.
Exponential attractors for a Cahn-Hilliard model in bounded domains with permeable walls
Directory of Open Access Journals (Sweden)
Ciprian G. Gal
2006-11-01
Full Text Available In a previous article [7], we proposed a model of phase separation in a binary mixture confined to a bounded region which may be contained within porous walls. The boundary conditions were derived from a mass conservation law and variational methods. In the present paper, we study the problem further. Using a Faedo-Galerkin method, we obtain the existence and uniqueness of a global solution to our problem, under more general assumptions than those in [7]. We then study its asymptotic behavior and prove the existence of an exponential attractor (and thus of a global attractor with finite dimension.
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...
Trial-by-trial identification of categorization strategy using iterative decision-bound modeling.
Hélie, Sébastien; Turner, Benjamin O; Crossley, Matthew J; Ell, Shawn W; Ashby, F Gregory
2016-08-05
Identifying the strategy that participants use in laboratory experiments is crucial in interpreting the results of behavioral experiments. This article introduces a new modeling procedure called iterative decision-bound modeling (iDBM), which iteratively fits decision-bound models to the trial-by-trial responses generated from single participants in perceptual categorization experiments. The goals of iDBM are to identify: (1) all response strategies used by a participant, (2) changes in response strategy, and (3) the trial number at which each change occurs. The new method is validated by testing its ability to identify the response strategies used in noisy simulated data. The benchmark simulation results show that iDBM is able to detect and identify strategy switches during an experiment and accurately estimate the trial number at which the strategy change occurs in low to moderate noise conditions. The new method is then used to reanalyze data from Ell and Ashby (2006). Applying iDBM revealed that increasing category overlap in an information-integration category learning task increased the proportion of participants who abandoned explicit rules, and reduced the number of training trials needed to abandon rules in favor of a procedural strategy. Finally, we discuss new research questions made possible through iDBM.
A new bounding-surface plasticity model for cyclic behaviors of saturated clay
Hu, Cun; Liu, Haixiao
2015-05-01
A new combined isotropic-kinematic hardening rule is proposed based on the concept of the generalized homological center and the generalization of Masing's rule. The key point of the new hardening rule is that the unloading event can be treated as if it were virgin loading through taking the stress reversal point as the new generalized homological center of the bounding surface. Therefore, a new simple bounding-surface plasticity model with three important features for the cyclic behaviors of saturated clay is developed. Firstly, according to the movement of the generalized homological center, the model can harden not only isotropically but also kinematically to account for the anisotropy and memory the particular loading events. Secondly, the continuous cyclic loading is divided into the first loading, unloading and reloading processes and they are treated differently when calculating the hardening modulus to describe the soil responses accurately. The third feature is taking the generalized homological center as the mapping origin in the mapping rule to reflect the plastic flow in the unloading event. The behaviors of saturated clay for the monotonic and cyclic stress-controlled and strain-controlled triaxial tests are simulated by the model. The prediction results show an encouraging agreement with the experimental data.
Jacquin, A. P.
2012-04-01
This study analyses the effect of precipitation spatial distribution uncertainty on the uncertainty bounds of a snowmelt runoff model's discharge estimates. Prediction uncertainty bounds are derived using the Generalized Likelihood Uncertainty Estimation (GLUE) methodology. The model analysed is a conceptual watershed model operating at a monthly time step. The model divides the catchment into five elevation zones, where the fifth zone corresponds to the catchment glaciers. Precipitation amounts at each elevation zone i are estimated as the product between observed precipitation (at a single station within the catchment) and a precipitation factor FPi. Thus, these factors provide a simplified representation of the spatial variation of precipitation, specifically the shape of the functional relationship between precipitation and height. In the absence of information about appropriate values of the precipitation factors FPi, these are estimated through standard calibration procedures. The catchment case study is Aconcagua River at Chacabuquito, located in the Andean region of Central Chile. Monte Carlo samples of the model output are obtained by randomly varying the model parameters within their feasible ranges. In the first experiment, the precipitation factors FPi are considered unknown and thus included in the sampling process. The total number of unknown parameters in this case is 16. In the second experiment, precipitation factors FPi are estimated a priori, by means of a long term water balance between observed discharge at the catchment outlet, evapotranspiration estimates and observed precipitation. In this case, the number of unknown parameters reduces to 11. The feasible ranges assigned to the precipitation factors in the first experiment are slightly wider than the range of fixed precipitation factors used in the second experiment. The mean squared error of the Box-Cox transformed discharge during the calibration period is used for the evaluation of the
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...... and its denotative meaning floating, we propose that bounded rational managers base their decisions on a simple heuristic, i.e. selecting and cultivating individuals so that their capabilities resemble their own capabilities the most (Adamsen 2015). We model the consequences of this talent management...... heuristic by varying the capabilities of today’s managers, which in turn impact which individuals will be selected as talent. We model the average level of capabilities and the distribution thereof in the sample where managers identify and select individuals from. We consider varying degrees of path...
Bolton, Matthew L; Bass, Ellen J
2010-09-01
Breakdowns in complex systems often occur as a result of system elements interacting in ways unanticipated by analysts or designers. In systems with human operators, human-automation interaction associated with both normative and erroneous human behavior can contribute to such failures. This paper presents a method for automatically generating task analytic models encompassing both erroneous and normative human behavior from normative task models. The resulting model can be integrated into a formal system model so that system safety properties can be formally verified with a model checker. This allows analysts to prove that a human automation-interactive system (as represented by the model) will or will not satisfy safety properties with both normative and generated erroneous human behavior. This method is illustrated with a case study: the operation of a radiation therapy machine. In this example, a problem resulting from a generated erroneous human action is discovered. Future extensions of our method are discussed.
Out-of-Bounds Array Access Fault Model and Automatic Testing Method Study
Institute of Scientific and Technical Information of China (English)
GAO Chuanping; DUAN Miyi; TAN Liqun; GONG Yunzhan
2007-01-01
Out-of-bounds array access(OOB) is one of the fault models commonly employed in the objectoriented programming language. At present, the technology of code insertion and optimization is widely used in the world to detect and fix this kind of fault. Although this method can examine some of the faults in OOB programs, it cannot test programs thoroughly, neither to find the faults correctly. The way of code insertion makes the test procedures so inefficient that the test becomes costly and time-consuming. This paper, uses a kind of special static test technology to realize the fault detection in OOB programs. We first establish the fault models in OOB program, and then develop an automatic test tool to detect the faults. Some experiments have exercised and the results show that the method proposed in the paper is efficient and feasible in practical applications.
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.)
概率线性时段不变式的统计模型检验%Statistical Model Checking of Probabilistic Linear Duration Invariants
Institute of Scientific and Technical Information of China (English)
安杰
2014-01-01
模型检验是软件工程形式化方法的一个重要组成部分，线性时段不变式是形式化方法中表述系统性质的一种重要表达式。对线性时段不变式的模型检验一直是形式化方法研究的一个重要内容。该文提出了一种针对带概率的线性时段不变式的模型检验方法，该方法针对不带有不确定性的概率模型，运用统计模型检验的方法，基于UPPAAL工具实现了概率线性时段不变式的统计模型检验。%Model Checking is a very important formal method in software engineering. Linear Duration Invariants are important safety properties of real-time systems, which form a decidable subclass of Duration Calculus formulas. In this paper, we propose a verification method for model checking the probabilistic linear duration invariants, based the stochastic models which do not have any nondeterminism. As the results, a model checking tools based on UPPAAL has been developed.
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.
模型检测网络传播干预策略%Model Checking Network Transmission Intervention Policies
Institute of Scientific and Technical Information of China (English)
余鹏; 魏欧; 韩兰胜; 牛耘
2014-01-01
Network exists widely in nature and human society. The spread of infections, such as computer viruses, diseases and rumors, poses great challenges to economic and societal system. It is an important issue in the network transmission control to protect individuals by finding effective intervention policies. This paper focuses on the net-work transmission model affected by time and adjacent nodes. Based on existing static protection work, a further study on dynamic protection cases is conducted, and four kinds of analyses of intervention policies are summarized. The intervention goals are expressed as logical properties and an effective approach of searching for intervention policies via model checking is proposed. Furthermore, experiments on random and small-world networks are con-ducted, demonstrating the advantages and disadvantages of model checkers NuSMV and SPIN on solving intervention problems. The results indicate that NuSMV needs less memory, but more time to complete searching, for example three times are unfinished in total six trails because of time exceeding in the dynamic recoverable problem;SPIN needs less time, but more memory, for example one time is unfinished in total six trails because of memory exceeding in the static unrecoverable problem.%网络广泛存在于自然界和人类生活中，计算机病毒、传染疾病、森林火灾和社会流言等在网络中的传播给经济、社会带来巨大挑战，寻找有效的干预策略实现对网络传播的控制是一个重要的研究问题。对受时间和邻接点影响的网络传播模型进行了重点关注，在已有静态保护工作的基础上，进一步研究了动态保护情况，总结了4类相关的干预策略分析问题；通过将干预目标描述为相应的时序逻辑属性，给出了通过模型检测找出有效的干预策略以抑制传播的方法。针对随机和小世界两种网络，比较分析了NuSMV和SPIN两种模型检测工具在解决具体网
Variational Worldline Approximation for the Relativistic Two-Body Bound State in a Scalar Model
Barro-Bergfl"odt, K; Stingl, M
2006-01-01
We use the worldline representation of field theory together with a variational approximation to determine the lowest bound state in the scalar Wick-Cutkosky model where two equal-mass constituents interact via the exchange of mesons. Self-energy and vertex corrections are included approximately in a consistent way as well as crossed diagrams. Only vacuum-polarization effects of the heavy particles are neglected. In a path integral description of an appropriate current-current correlator an effective, retarded action is obtained by integrating out the meson field. As in the polaron problem we employ a quadratic trial action with variational functions to describe retardation and binding effects through multiple meson exchange.The variational equations for these functions are derived, discussed qualitatively and solved numerically. We compare our results with the ones from traditional approaches based on the Bethe-Salpeter equation and find an enhanced binding. For weak coupling this is worked out analytically ...
Lower Bounds for Sorted Geometric Queries in the I/O Model
DEFF Research Database (Denmark)
Afshani, Peyman; Zeh, Norbert
2012-01-01
problems is to construct a small data structure that can answer queries efficiently. We study sorted geometric query problems in the I/O model and prove that, when limited to linear space, the naïve approach of sorting the elements in S in the desired output order from scratch is the best possible....... This is highly relevant in an I/O context because storing a massive data set in a superlinear-space data structure is often infeasible. We also prove that answering queries using I/Os requires space, where N is the input size, B is the block size, and M is the size of the main memory. This bound is unlikely...
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.
Solution of the spatial neutral model yields new bounds on the Amazonian species richness
Shem-Tov, Yahav; Danino, Matan; Shnerb, Nadav M.
2017-02-01
Neutral models, in which individual agents with equal fitness undergo a birth-death-mutation process, are very popular in population genetics and community ecology. Usually these models are applied to populations and communities with spatial structure, but the analytic results presented so far are limited to well-mixed or mainland-island scenarios. Here we combine analytic results and numerics to obtain an approximate solution for the species abundance distribution and the species richness for the neutral model on continuous landscape. We show how the regional diversity increases when the recruitment length decreases and the spatial segregation of species grows. Our results are supported by extensive numerical simulations and allow one to probe the numerically inaccessible regime of large-scale systems with extremely small mutation/speciation rates. Model predictions are compared with the findings of recent large-scale surveys of tropical trees across the Amazon basin, yielding new bounds for the species richness (between 13100 and 15000) and the number of singleton species (between 455 and 690).
The Dynamic Checking of Complex Real Time System
Institute of Scientific and Technical Information of China (English)
YU Chao; HUANG Benwen; WU Guoqing
2006-01-01
The paper presents an dynamic execution model of complex real-time software based on requirement description model RTRSM, and then propose a checking method based on configuration covering and its corresponding algorithm. This checking method can check the execution situations between parallel elements in a dynamic execution step of real-time software systems. It also can check all the states and transitions which assure the completeness of checking. In the end, related theorem is proofed.
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.
Rodgers, A. J.; Xie, X.; Petersson, A.
2007-12-01
The next major earthquake in the San Francisco Bay area is likely to occur on the Hayward-Rodgers Creek Fault system. Attention on the southern Hayward section is appropriate given the upcoming 140th anniversary of the 1868 M 7 rupture coinciding with the estimated recurrence interval. This presentation will describe ground motion simulations for large (M > 6.5) earthquakes on the Hayward Fault using a recently developed elastic finite difference code and high-performance computers at Lawrence Livermore National Laboratory. Our code easily reads the recent USGS 3D seismic velocity model of the Bay Area developed in 2005 and used for simulations of the 1906 San Francisco and 1989 Loma Prieta earthquakes. Previous work has shown that the USGS model performs very well when used to model intermediate period (4-33 seconds) ground motions from moderate (M ~ 4-5) earthquakes (Rodgers et al., 2008). Ground motions for large earthquakes are strongly controlled by the hypocenter location, spatial distribution of slip, rise time and directivity effects. These are factors that are impossible to predict in advance of a large earthquake and lead to large epistemic uncertainties in ground motion estimates for scenario earthquakes. To bound this uncertainty, we are performing suites of simulations of scenario events on the Hayward Fault using stochastic rupture models following the method of Liu et al. (Bull. Seism. Soc. Am., 96, 2118-2130, 2006). These rupture models have spatially variable slip, rupture velocity, rise time and rake constrained by characterization of inferred finite fault ruptures and expert opinion. Computed ground motions show variability due to the variability in rupture models and can be used to estimate the average and spread of ground motion measures at any particular site. This work was performed under the auspices of the U.S. Department of Energy by University of California Lawrence Livermore National Laboratory under contract No.W-7405-Eng-48. This is
Calvert, S.C.; Snelder, M.; Taale, H.; Wageningen-Kessels, F.L.M. van; Hoogendoorn, S.P.
2015-01-01
In this contribution a model-based analysis of the application of bounded acceleration in traffic flow is considered as a cause for the capacity drop. This is performed in a Lagrangian formulation of the kinematic wave model with general vehicle specific characteristics. Unconstrained overtaking is
Binswanger, J.
2010-01-01
This paper develops a new life cycle model that aims to describe the savings and asset allocation choices of boundedly rational agents. In this model, agents make forward-looking decisions without the requirement of anticipating their actual future decisions. Instead, agents pursue two simple so-cal
Energy Technology Data Exchange (ETDEWEB)
Royo, B.; Valdes, R.
2012-11-01
This report contains the description and the results of the dynamic simulation model that has been developed to predict the behaviour of one of our lift check valve design. The aim of the model is not only to simulate the closing process of the valve and to product the magnitude of the water hammer effect that may appear immediately after the valve closing, but also to simulate several design version until obtain the optimum which further minimizes such effect. the input data used for this study ensure reliable results since they represent a real system. (Author)
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-+.
Bound states in the 3d Ising model and implications for QCD at finite temperature and density
Caselle, M; Provero, P; Zarembo, K
2002-01-01
We study the spectrum of bound states of the three dimensional Ising model in the (h,beta) plane near the critical point. We show the existence of an unbinding line, defined as the boundary of the region where bound states exist. Numerical evidence suggests that this line coincides with the beta=beta_c axis. When the 3D Ising model is considered as an effective description of hot QCD at finite density, we conjecture the correspondence between the unbinding line and the line that separates the quark-gluon plasma phase from the superconducting phase. The bound states of the Ising model are conjectured to correspond to the diquarks of the latter phase of QCD.
对象角色模型局部语义冲突即时检查方法研究%Research on local semantic conflicts instantly check methods for ORM model
Institute of Scientific and Technical Information of China (English)
潘文林
2015-01-01
The object of existing ORM model checking methods for semantic conflict is global model. Each check will take a long time, can’t meet the needs of modeling tools to instant check. 10 kinds of local semantic conflict check pattern and algorithm have been proposed to instantly check ORM model. The basic idea is:limiting the scope of the semantic conflict check, abstracting a series of local model check pattern based on the characteristic of local model structure, and then local semantic conflicts which are caused by the new model elements can be instantly checked based on local model check patterns.%现有的ORM模型语义冲突检查方法针对的是全局模型，检查时间长，不能支持建模工具即时检查的需要。为满足即时检查ORM模型的要求，提出了10种局部语义冲突检查模式和算法。基本思想是：通过限定语义冲突检查范围，将局部模型结构抽象为各种模式来检查新增模型元素可能引起的局部语义冲突。该方法能有效提升建模工具的可用性和模型质量。
Structural ensemble dynamics based closure model for wall-bounded turbulent flow
Institute of Scientific and Technical Information of China (English)
Zhen-Su She; Ning Hu; You Wu
2009-01-01
Wall-bounded turbulent flow involves the development of multi-scale turbulent eddies, as well as a sharply varying boundary layer. Its theoretical descriptions are yet phenomenological. We present here a new framework called structural ensemble dynamics (SED), which aims at using systematically all relevant statistical properties of turbulent structures for a quantitative description of ensemble means. A new set of closure equations based on the SED approach for a turbulent channel flow is presented. SED order functions are defined, and numerically determined from data of direct numerical simulations (DNS). Computational results show that the new closure model reproduces accurately the solution of the original Navier-Stokes simulation, including the mean velocity profile, the kinetic energy of the stream-wise velocity component, and every term in the energy budget equation. It is suggested that the SED-based studies of turbulent structure builds a bridge between the studies of physical mechanisms of turbulence and the development of accurate model equations for engineering predictions.
Carro, Adrian; Miguel, Maxi San
2012-01-01
We study a model for continuous-opinion dynamics under bounded confidence. In particular, we analyze the importance of the initial distribution of opinions in determining the asymptotic configuration. Thus, we sketch the structure of attractors of the dynamical system, by means of the numerical computation of the time evolution of the agents density. We show that, for a given bound of confidence, a consensus can be encouraged or prevented by certain initial conditions. Furthermore, a noisy perturbation is added to the system with the purpose of modeling the free will of the agents. As a consequence, the importance of the initial condition is partially replaced by that of the statistical distribution of the noise. Nevertheless, we still find evidence of the influence of the initial state upon the final configuration for a short range of the bound of confidence parameter.
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....
Bound entanglement and entanglement bounds
Energy Technology Data Exchange (ETDEWEB)
Sauer, Simeon [Physikalisch-Astronomische Fakultaet, Friedrich-Schiller-Univesitaet Jena (Germany)]|[Physikalisches Institut, Albert-Ludwigs-Universitaet Freiburg, Hermann-Herder-Strasse 3, D-79104 Freiburg (Germany); Melo, Fernando de; Mintert, Florian; Buchleitner, Andreas [Physikalisches Institut, Albert-Ludwigs-Universitaet Freiburg, Hermann-Herder-Strasse 3, D-79104 Freiburg (Germany)]|[Max-Planck-Institut fuer Physik komplexer Systeme, Noethnitzer Str.38, D-01187 Dresden (Germany); Bae, Joonwoo [School of Computational Sciences, Korea Institute for Advanced Study, Seoul 130-012 (Korea); Hiesmayr, Beatrix [Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna (Austria)
2008-07-01
We investigate the separability of Bell-diagonal states of two qutrits. By using lower bounds to algebraically estimate concurrence, we find convex regions of bound entangled states. Some of these regions exactly coincide with the obtained results when employing optimal entanglement witnesses, what shows that the lower bound can serve as a precise detector of entanglement. Some hitherto unknown regions of bound entangled states were discovered with this approach, and delimited efficiently.
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.
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
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...
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.
Formation and condensation of excitonic bound states in the generalized Falicov-Kimball model
Farkašovský, Pavol
2017-01-01
The density-matrix-renormalization-group method and the Hartree-Fock approximation with the charge-density-wave instability are used to study a formation and condensation of excitonic bound states in the generalized Falicov-Kimball model. In particular, we examine effects of various factors, such as the f -electron hopping, the local and nonlocal hybridizations, as well as the increasing dimension of the system on the excitonic momentum distribution N (q ) and especially on the number of zero-momentum excitons N0=N (q =0 ) in the condensate. It is found that the negative values of the f -electron hopping integrals tf support the formation of a zero-momentum condensate, whereas the positive values of tf have the fully opposite effect. The opposite effects on the formation of the condensate exhibit also the local and nonlocal hybridizations. The first one strongly supports the formation of the condensate, whereas the second one destroys it completely. Moreover, it was shown that the zero-momentum condensate remains robust with increasing dimension of the system.
Dark-polariton bound pairs in the modified Jaynes-Cummings-Hubbard model
Maggitti, A.; Radonjić, M.; Jelenković, B. M.
2016-01-01
We investigate a one-dimensional modified Jaynes-Cummings-Hubbard chain of N identical QED cavities with nearest-neighbor photon tunneling and periodic boundary conditions. Each cavity contains an embedded three-level atom which is coupled to a cavity mode and an external classical control field. In the case of two excitations and common large detuning of two Raman-resonant fields, we show the emergence of two different species of dark-polariton bound pairs (DPBPs) that are mutually localized in their relative spatial coordinates. Due to the high degree of controllability, we show the appearance of either one or two DPBPs, having the energies within the energy gaps between three bands of mutually delocalized eigenstates. Interestingly, in a different parameter regime with negatively detuned Raman fields, we find that the ground state of the system is a DPBP which can be utilized for the photon storage, retrieval, and controllable state preparation. Moreover, we propose an experimental realization of our model system.
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 introduced. Using spectral element simulations of stream function waves it is illustrated that (i) the bounded equations capture the physics of the wave motion as well as the standard unbounded equations, and (ii) the bounded equations are computationally more efficient when explicit time-stepping schemes...
A Lower Bound on the Lyapunov Exponent for the Generalized Harper's Model
Jitomirskaya, Svetlana; Liu, Wencai
2017-02-01
We obtain a lower bound for the Lyapunov exponent of a family of discrete Schrödinger operators (Hu)_n=u_{n+1}+u_{n-1}+2a_1 cos 2π (θ +nα )u_n+2a_2 cos 4π (θ +nα )u_n, that incorporates both a_1 and a_2, thus going beyond the Herman's bound.
A Lower Bound on the Lyapunov Exponent for the Generalized Harper's Model
Jitomirskaya, Svetlana; Liu, Wencai
2016-05-01
We obtain a lower bound for the Lyapunov exponent of a family of discrete Schrödinger operators (Hu)_n=u_{n+1}+u_{n-1}+2a_1 cos 2π (θ +nα )u_n+2a_2 cos 4π (θ +nα )u_n , that incorporates both a_1 and a_2, thus going beyond the Herman's bound.
Becis-Aubry, Yasmina; Boutayeb, Mohamed; Darouach, Mohamed
2006-01-01
International audience; This contribution proposes a recursive and easily implementable online algorithm for state estimation of multi-output discrete-time systems with nonlinear dynamics and linear measurements in presence of unknown but bounded disturbances corrupting both the state and measurement equations. The proposed algorithm is based on state bounding techniques and is decomposed into two steps : time update and observation update that uses a switching estimation Kalman-like gain mat...
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…
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...
Optimal Bounds in Parametric LTL Games
Directory of Open Access Journals (Sweden)
Martin Zimmermann
2011-06-01
Full Text Available We consider graph games of infinite duration with winning conditions in parameterized linear temporal logic, where the temporal operators are equipped with variables for time bounds. In model checking such specifications were introduced as "PLTL" by Alur et al. and (in a different version called "PROMPT-LTL" by Kupferman et al.. We present an algorithm to determine optimal variable valuations that allow a player to win a game. Furthermore, we show how to determine whether a player wins a game with respect to some, infinitely many, or all valuations. All our algorithms run in doubly-exponential time; so, adding bounded temporal operators does not increase the complexity compared to solving plain LTL games.
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
Wishart, Justin Rory
2011-01-01
In this paper, a lower bound is determined in the minimax sense for change point estimators of the first derivative of a regression function in the fractional white noise model. Similar minimax results presented previously in the area focus on change points in the derivatives of a regression function in the white noise model or consider estimation of the regression function in the presence of correlated errors.
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.
Bureau of Employment Security (DOL), Washington, DC.
The original edition of the Department of Labor Interest Check List aims at helping students decide what kinds of work they would like and lists activities that are found in a broad range of industries and occupations. The student is advised to read each of approximately 175 items and indicate how he feels about the activity described by placing a…
Checking BEBC superconducting magnet
1974-01-01
The superconducting coils of the magnet for the 3.7 m Big European Bubble Chamber (BEBC) had to be checked, see Annual Report 1974, p. 60. The photo shows a dismantled pancake. By December 1974 the magnet reached again the field design value of 3.5 T.
Hoijtink, H; Molenaar, IW
1997-01-01
In this paper it will be shown that a certain class of constrained latent class models may be interpreted as a special case of nonparametric multidimensional item response models. The parameters of this latent class model will be estimated using an application of the Gibbs sampler. It will be illust
Bounds for the price of a European-style Asian option in a binary tree model
Reynaerts, H; Vanmaele, M.; Dhaene, J.L.M.; Deelstra, G.
2006-01-01
Inspired by the ideas of Rogers and Shi [J. Appl. Prob. 32 (1995) 1077], Chalasani et al. [J. Comput. Finance 1(4) (1998) 11] derived accurate lower and upper bounds for the price of a European-style Asian option with continuous averaging over the full lifetime of the option, using a discrete-time b
Stable Model Reference Adaptive Control in the Presence of Bounded Disturbances,
1981-03-01
IEEE Transactions on Automatic Control , Vol...AC-25, No. 3, June 1980. [2) A. Stephen Morse, "Global Stability of Parameter-Adaptive Control Systems," IEEE Transactions on Automatic Control , Vol...34 IEEE Transactions on Automatic Control , Vol. AC-25, No. 3, June 1980. [41 Benjamin B. Peterson and Kumpati S. Narendra, "Bounded Error
Tricritical points in a Vicsek model of self-propelled particles with bounded confidence.
Romensky, Maksym; Lobaskin, Vladimir; Ihle, Thomas
2014-12-01
We study the orientational ordering in systems of self-propelled particles with selective interactions. To introduce the selectivity we augment the standard Vicsek model with a bounded-confidence collision rule: a given particle only aligns to neighbors who have directions quite similar to its own. Neighbors whose directions deviate more than a fixed restriction angle α are ignored. The collective dynamics of this system is studied by agent-based simulations and kinetic mean-field theory. We demonstrate that the reduction of the restriction angle leads to a critical noise amplitude decreasing monotonically with that angle, turning into a power law with exponent 3/2 for small angles. Moreover, for small system sizes we show that upon decreasing the restriction angle, the kind of the transition to polar collective motion changes from continuous to discontinuous. Thus, an apparent tricritical point with different scaling laws is identified and calculated analytically. We investigate the shifting and vanishing of this point due to the formation of density bands as the system size is increased. Agent-based simulations in small systems with large particle velocities show excellent agreement with the kinetic theory predictions. We also find that at very small interaction angles, the polar ordered phase becomes unstable with respect to the apolar phase. We derive analytical expressions for the dependence of the threshold noise on the restriction angle. We show that the mean-field kinetic theory also permits stationary nematic states below a restriction angle of 0.681π. We calculate the critical noise, at which the disordered state bifurcates to a nematic state, and find that it is always smaller than the threshold noise for the transition from disorder to polar order. The disordered-nematic transition features two tricritical points: At low and high restriction angle, the transition is discontinuous but continuous at intermediate α. We generalize our results to systems
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.
A case study to quantify prediction bounds caused by model-form uncertainty of a portal frame
Van Buren, Kendra L.; Hall, Thomas M.; Gonzales, Lindsey M.; Hemez, François M.; Anton, Steven R.
2015-01-01
Numerical simulations, irrespective of the discipline or application, are often plagued by arbitrary numerical and modeling choices. Arbitrary choices can originate from kinematic assumptions, for example the use of 1D beam, 2D shell, or 3D continuum elements, mesh discretization choices, boundary condition models, and the representation of contact and friction in the simulation. This work takes a step toward understanding the effect of arbitrary choices and model-form assumptions on the accuracy of numerical predictions. The application is the simulation of the first four resonant frequencies of a one-story aluminum portal frame structure under free-free boundary conditions. The main challenge of the portal frame structure resides in modeling the joint connections, for which different modeling assumptions are available. To study this model-form uncertainty, and compare it to other types of uncertainty, two finite element models are developed using solid elements, and with differing representations of the beam-to-column and column-to-base plate connections: (i) contact stiffness coefficients or (ii) tied nodes. Test-analysis correlation is performed to compare the lower and upper bounds of numerical predictions obtained from parametric studies of the joint modeling strategies to the range of experimentally obtained natural frequencies. The approach proposed is, first, to characterize the experimental variability of the joints by varying the bolt torque, method of bolt tightening, and the sequence in which the bolts are tightened. The second step is to convert what is learned from these experimental studies to models that "envelope" the range of observed bolt behavior. We show that this approach, that combines small-scale experiments, sensitivity analysis studies, and bounding-case models, successfully produces lower and upper bounds of resonant frequency predictions that match those measured experimentally on the frame structure. (Approved for unlimited, public
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.
Pre-Test Assessment of the Upper Bound of the Drag Coefficient Repeatability of a Wind Tunnel Model
Ulbrich, N.; L'Esperance, A.
2017-01-01
A new method is presented that computes a pre{test estimate of the upper bound of the drag coefficient repeatability of a wind tunnel model. This upper bound is a conservative estimate of the precision error of the drag coefficient. For clarity, precision error contributions associated with the measurement of the dynamic pressure are analyzed separately from those that are associated with the measurement of the aerodynamic loads. The upper bound is computed by using information about the model, the tunnel conditions, and the balance in combination with an estimate of the expected output variations as input. The model information consists of the reference area and an assumed angle of attack. The tunnel conditions are described by the Mach number and the total pressure or unit Reynolds number. The balance inputs are the partial derivatives of the axial and normal force with respect to all balance outputs. Finally, an empirical output variation of 1.0 microV/V is used to relate both random instrumentation and angle measurement errors to the precision error of the drag coefficient. Results of the analysis are reported by plotting the upper bound of the precision error versus the tunnel conditions. The analysis shows that the influence of the dynamic pressure measurement error on the precision error of the drag coefficient is often small when compared with the influence of errors that are associated with the load measurements. Consequently, the sensitivities of the axial and normal force gages of the balance have a significant influence on the overall magnitude of the drag coefficient's precision error. Therefore, results of the error analysis can be used for balance selection purposes as the drag prediction characteristics of balances of similar size and capacities can objectively be compared. Data from two wind tunnel models and three balances are used to illustrate the assessment of the precision error of the drag coefficient.
Baryon-baryon bound states in a (2+1)-dimensional lattice QCD model
Faria da Veiga, Paulo A.; O'Carroll, Michael; Schor, Ricardo
2003-08-01
We consider bound states of two baryons (antibaryons) in lattice QCD in a Euclidean formulation. For simplicity, we analyze an SU(3) theory with a single flavor in 2+1 dimensions and two-dimensional Dirac matrices. For a small hopping parameter 0<κ≪1 and large glueball mass, we recently showed the existence of a (anti)baryonlike particle, with an asymptotic mass of the order of -3 ln κ and with an isolated dispersion curve, i.e., an upper gap property persisting up to near the meson-baryon threshold, which is of order -5 ln κ. Here, we show that there is no baryon-baryon (or antibaryon-antibaryon) bound state solution to the Bethe-Salpeter equation up to the two-baryon threshold, which is approximately -6 ln κ.
Check Verbraucherpolitik und Verbraucherbeteiligung
DEFF Research Database (Denmark)
Hagen, Kornelia; Micklitz, Hans-W.; Oehler, Andreas;
2013-01-01
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 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...... an empirically based “Check Consumer Policy and Consumer Participation” as a systematic decision and evaluation tool for policy makers. This check should be independent from the government and should be grounded on an empirical view of the consumer. Consumer policy tools should be tested with real consumers...
A Theory of Cramer-Rao Bounds for Constrained Parametric Models
2010-01-01
1980. [65] M. Spivak , Calculus on Manifolds. Reading, MA: Addison-Wesley, 1965. [66] Petre Stoica, Thomas L. Marzetta, “Parameter estimation problems...multivariable calculus and, specifically, the use of the implicit function theorem. The reward for this approach will be a seamless presentation of statistical...inference involving the constrained Cramér-Rao bound. From the perspective of multivariable calculus , the constraint f (θ) = 0 effec- tively restricts
Quantization of the Closed Mini-Superspace Models as Bound States
Kung, J H
1995-01-01
Wheeler-DeWitt equation is applied to $k > 0$ Friedmann Robertson Walker metric with various types of matter. It is shown that if the Universe ends in the matter dominated era (e.g., radiation or pressureless gas) with zero cosmological constant, then the resulting Wheeler-DeWitt equation describes a bound state problem. As solutions of a non-degenerate bound state system, the eigen-wave functions are real (Hartle-Hawking) and the usual issue associated with the ambiguity in the boundary conditions for the wave functions is resolved. Furthermore, as a bound state problem, there exists a quantization condition that relates the curvature of the three space with the energy density of the Universe. Incorporating a cosmological constant in the early Universe (inflation) is given as a natural explanation for the large quantum number associated with our Universe, which resulted from the quantization condition. It is also shown that if there is a cosmological constant $\\Lambda > 0$ in our Universe that persists for a...
Meson-baryon bound states in a (2+1)-dimensional strongly coupled lattice QCD model
Neto, Antônio Francisco
2004-08-01
We consider bound states of a meson and a baryon (meson and antibaryon) in lattice QCD in a Euclidean formulation. For simplicity, considering the + parity sector we analyze an SU(3) theory with a single flavor in 2+1 dimensions and two-dimensional Dirac matrices. We work in the strong coupling regime, i.e., in a region of parameters such that the hopping parameter κ is sufficiently small and κ≫g-20, where g-20 is the pure gauge coupling. There is a meson (baryon) particle with asymptotic mass -2 ln κ (-3 ln κ) and an isolated dispersion curve. Here, in a ladder approximation, we show that there is no meson baryon (or meson-antibaryon) bound state solution to the Bethe-Salpeter equation up to the meson-baryon threshold (˜-5 ln κ). The absence of such a bound state is an effect of a spatial range-one repulsive potential that is local in space at order κ3, i.e., the leading order in the hopping parameter κ.
Performance of Compiler-Assisted Memory Safety Checking
2014-08-01
Performance of Compiler -Assisted Memory Safety Checking David Keaton Robert C. Seacord August 2014 TECHNICAL NOTE CMU/SEI-2014-TN...014 | vii Abstract Buffer overflows affect a large installed base of C code. This technical note describes the criteria for deploying a compiler ...describes a modification to the LLVM compiler to enable hoisting bounds checks from loops and functions. This proof-of-concept prototype has been used
Powell, John D.; Owens, David; Menzies, Tim
2004-01-01
The difficulty of how to test large systems, such as the one on board a NASA robotic remote explorer (RRE) vehicle, is fundamentally a search issue: the global state space representing all possible has yet to be solved, even after many decades of work. Randomized algorithms have been known to outperform their deterministic counterparts for search problems representing a wide range of applications. In the case study presented here, the LURCH randomized algorithm proved to be adequate to the task of testing a NASA RRE vehicle. LURCH found all the errors found by an earlier analysis of a more complete method (SPIN). Our empirical results are that LURCH can scale to much larger models than standard model checkers like SMV and SPIN. Further, the LURCH analysis was simpler than the SPIN analysis. The simplicity and scalability of LURCH are two compelling reasons for experimenting further with this tool.
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
Requirements Specifications Checking of Embedded Real-Time Software
Institute of Scientific and Technical Information of China (English)
WU Guoqing(毋国庆); SHU Fengdi(舒风笛); WANG Min(王敏); CHEN Weiqing(陈伟清)
2002-01-01
After introducing the overview of our requirements description model HRFSM,the paper presents a dynamic software execution model (DERTS) of embedded real-time software, which can integrate control flow, data flow and time. Based on DERTS, a checking method is also presented. It consists of three kinds of checking and can check the consistency and completeness of the requirement specifications of embedded real-time software. Besides providing information helpful to improve the efficiency of analyzing and checking specifications,the checking method is flexible, and easy to understand and to use for the analyst.
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)
Dek, E.C.P.
2015-01-01
Obsessive-compulsive disorder (OCD) is characterized by persistent doubt. The majority of patients with OCD engage in repeated checking to reduce these feelings of uncertainty. However, numerous studies demonstrated that repetitive behavior ironically increases uncertainty: perseverative checking in
Parton energy loss at strong coupling and the universal bound
Kharzeev, D E
2008-01-01
The apparent universality of jet quenching observed in heavy ion collisions at RHIC for light and heavy quarks, as well as for quarks and gluons, is very puzzling and calls for a theoretical explanation. Recently it has been proposed that the synchrotron--like radiation at strong coupling gives rise to a universal bound on the energy of a parton escaping from the medium. Since this bound appears quite low, almost all of the observed particles at high transverse momentum have to originate from the surface of the hot fireball. Here I make a first attempt of checking this scenario against the RHIC data and formulate a "Universal Bound Model" of jet quenching that can be further tested at RHIC and LHC.
Institute of Scientific and Technical Information of China (English)
Zhiping Qiu; Xiaojun Wang
2006-01-01
Two non-probabilistic, set-theoretical methods for determining the maximum and minimum impulsive responses of structures to uncertain-but-bounded impulses are presented. They are, respectively, based on the theories of interval mathematics and convex models. The uncertain-but-bounded impulses are assumed to be a convex set, hyper-rectangle or ellipsoid. For the two non-probabilistic methods, less prior information is required about the uncertain nature of impulses than the probabilistic model. Comparisons between the interval analysis method and the convex model, which are developed as an anti-optimization problem of finding the least favorable impulsive response and the most favorable impulsive response, are made through mathematical analyses and numerical calculations.The results of this study indicate mat under the condition of the interval vector being determined from an ellipsoid containing the uncertain impulses, the width of the impulsive responses predicted by the interval analysis method is larger than that by the convex model; under the condition of the ellipsoid being determined from an interval vector containing the uncertain impulses, the width Of the interval impulsive responses obtained by the interval analysis method is smaller than that by the convex model.
Pack, Robert C.; Standiford, Keith; Lukanc, Todd; Ning, Guo Xiang; Verma, Piyush; Batarseh, Fadi; Chua, Gek Soon; Fujimura, Akira; Pang, Linyong
2014-10-01
A methodology is described wherein a calibrated model-based `Virtual' Variable Shaped Beam (VSB) mask writer process simulator is used to accurately verify complex Optical Proximity Correction (OPC) and Inverse Lithography Technology (ILT) mask designs prior to Mask Data Preparation (MDP) and mask fabrication. This type of verification addresses physical effects which occur in mask writing that may impact lithographic printing fidelity and variability. The work described here is motivated by requirements for extreme accuracy and control of variations for today's most demanding IC products. These extreme demands necessitate careful and detailed analysis of all potential sources of uncompensated error or variation and extreme control of these at each stage of the integrated OPC/ MDP/ Mask/ silicon lithography flow. The important potential sources of variation we focus on here originate on the basis of VSB mask writer physics and other errors inherent in the mask writing process. The deposited electron beam dose distribution may be examined in a manner similar to optical lithography aerial image analysis and image edge log-slope analysis. This approach enables one to catch, grade, and mitigate problems early and thus reduce the likelihood for costly long-loop iterations between OPC, MDP, and wafer fabrication flows. It moreover describes how to detect regions of a layout or mask where hotspots may occur or where the robustness to intrinsic variations may be improved by modification to the OPC, choice of mask technology, or by judicious design of VSB shots and dose assignment.
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.
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.)
Model checking mobile stochastic logic.
De Nicola, Rocco; Katoen, Joost-Pieter; Latella, Diego; Loreti, Michele; Massink, Mieke
2007-01-01
The Temporal Mobile Stochastic Logic (MOSL) has been introduced in previous work by the authors for formulating properties of systems specified in STOKLAIM, a Markovian extension of KLAIM. The main purpose of MOSL is to address key functional aspects of global computing such as distribution awarenes
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.
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...
Modelling and simulation of turbulence and heat transfer in wall-bounded flows
Popovac, M.
2006-01-01
At present it is widely accepted that there is no universal turbulence model, i.e. no turbulence model can give acceptably good predictions for all turbulent flows that are found in nature or engineering. Every turbulence model is based on certain assumptions, and hence it is aimed at certain type o
Ateshian, Gerard A; Nims, Robert J; Maas, Steve; Weiss, Jeffrey A
2014-10-01
Mechanobiological processes are rooted in mechanics and chemistry, and such processes may be modeled in a framework that couples their governing equations starting from fundamental principles. In many biological applications, the reactants and products of chemical reactions may be electrically charged, and these charge effects may produce driving forces and constraints that significantly influence outcomes. In this study, a novel formulation and computational implementation are presented for modeling chemical reactions in biological tissues that involve charged solutes and solid-bound molecules within a deformable porous hydrated solid matrix, coupling mechanics with chemistry while accounting for electric charges. The deposition or removal of solid-bound molecules contributes to the growth and remodeling of the solid matrix; in particular, volumetric growth may be driven by Donnan osmotic swelling, resulting from charged molecular species fixed to the solid matrix. This formulation incorporates the state of strain as a state variable in the production rate of chemical reactions, explicitly tying chemistry with mechanics for the purpose of modeling mechanobiology. To achieve these objectives, this treatment identifies the specific theoretical and computational challenges faced in modeling complex systems of interacting neutral and charged constituents while accommodating any number of simultaneous reactions where reactants and products may be modeled explicitly or implicitly. Several finite element verification problems are shown to agree with closed-form analytical solutions. An illustrative tissue engineering analysis demonstrates tissue growth and swelling resulting from the deposition of chondroitin sulfate, a charged solid-bound molecular species. This implementation is released in the open-source program FEBio ( www.febio.org ). The availability of this framework may be particularly beneficial to optimizing tissue engineering culture systems by examining the
Analysis of strictly bound modes in photonic crystal fibers by use of a source-model technique.
Hochman, Amit; Leviatan, Yehuda
2004-06-01
We describe a source-model technique for the analysis of the strictly bound modes propagating in photonic crystal fibers that have a finite photonic bandgap crystal cladding and are surrounded by an air jacket. In this model the field is simulated by a superposition of fields of fictitious electric and magnetic current filaments, suitably placed near the media interfaces of the fiber. A simple point-matching procedure is subsequently used to enforce the continuity conditions across the interfaces, leading to a homogeneous matrix equation. Nontrivial solutions to this equation yield the mode field patterns and propagation constants. As an example, we analyze a hollow-core photonic crystal fiber. Symmetry characteristics of the modes are discussed and exploited to reduce the computational burden.
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.
A Deep Structured Model with Radius-Margin Bound for 3D Human Activity Recognition
Lin, Liang; Wang, Keze; Zuo, Wangmeng; Wang, Meng; Luo, Jiebo; Zhang, Lei
2015-01-01
Understanding human activity is very challenging even with the recently developed 3D/depth sensors. To solve this problem, this work investigates a novel deep structured model, which adaptively decomposes an activity instance into temporal parts using the convolutional neural networks (CNNs). Our model advances the traditional deep learning approaches in two aspects. First, { we incorporate latent temporal structure into the deep model, accounting for large temporal variations of diverse huma...
Large-time behaviour of some fully discrete kinetic models in bounded domains
Directory of Open Access Journals (Sweden)
Ester Gabetta
1991-05-01
Full Text Available We investigate the large-time behaviour of the fully discretized version both of the three velocity Broadwell model and of the four velocity model in a strip. We analyze the different behaviours on the light of some recent results by M. Slemrod [7] and C. Cercignani [3].
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 ...
Fific, Mario; Little, Daniel R.; Nosofsky, Robert M.
2010-01-01
We formalize and provide tests of a set of logical-rule models for predicting perceptual classification response times (RTs) and choice probabilities. The models are developed by synthesizing mental-architecture, random-walk, and decision-bound approaches. According to the models, people make independent decisions about the locations of stimuli…
Ellison, Donald H.; Englander, Jacob A.; Conway, Bruce A.
2017-01-01
The multiple gravity assist low-thrust (MGALT) trajectory model combines the medium-fidelity Sims-Flanagan bounded-impulse transcription with a patched-conics flyby model and is an important tool for preliminary trajectory design. While this model features fast state propagation via Keplers equation and provides a pleasingly accurate estimation of the total mass budget for the eventual flight suitable integrated trajectory it does suffer from one major drawback, namely its temporal spacing of the control nodes. We introduce a variant of the MGALT transcription that utilizes the generalized anomaly from the universal formulation of Keplers equation as a decision variable in addition to the trajectory phase propagation time. This results in two improvements over the traditional model. The first is that the maneuver locations are equally spaced in generalized anomaly about the orbit rather than time. The second is that the Kepler propagator now has the generalized anomaly as its independent variable instead of time and thus becomes an iteration-free propagation method. The new algorithm is outlined, including the impact that this has on the computation of Jacobian entries for numerical optimization, and a motivating application problem is presented that illustrates the improvements that this model has over the traditional MGALT transcription.
Tree-level metastability bounds for the most general two Higgs doublet model
Ivanov, I P
2015-01-01
Within two Higgs doublet models, it is possible that the current vacuum is not the global minimum, in which case it could possibly decay at a later stage. We discuss the tree-level conditions which must be obeyed by the most general scalar potential in order to preclude that possibility. We propose a new procedure which is not only more general but also easier to implement than the previously published one, including CP conserving as well as CP violating scalar sectors. We illustrate these conditions within the context of the Z2 model, softly broken by a complex, CP violating parameter.
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......, the central tendency and stochastic volatility. Emphasis is placed on the particular class of exponential-affine term structure models that permits solving the bond pricing PDE in terms of a system of ODEs. It is assumed that coupon bond prices are contaminated by additive white noise, where the stochastic...
Hyperspherical three-body model calculation for the bound $^{1,3}$S-states of Coulombic systems
Khan, Md Abdul
2014-01-01
In this paper, hyperspherical three-body model formalism has been applied for the calculation energies of the low-lying bound $^{1,3}$S (L=0)-states of neutral helium and helium like Coulombic three-body systems having nuclear charge (Z) in the range Z=2 to Z=92. The calculation of the coupling potential matrix elements of the two-body potentials has been simplified by the introduction of Raynal-Revai Coefficients (RRC). The three-body wave function in the Schr\\H{o}dinger equation when expanded in terms of hyperpherical harmonics (HH), leads to an infinite set of coupled differential equation (CDE). For practical reason the infinite set of CDE is truncated to a finite set and are solved by an exact numerical method known as renormalized Numerov method (RNM) to get the energy solution (E). The calculated energy is compared with the ones of the literature.
A lower bound on {T SR}/{m H} in the O(4) model on anisotropic lattices
Gavai, R. V.; Heller, U. M.; Karsch, F.; Neuhaus, T.; Plache, B.
1992-11-01
Results of an investigation of the O(4) spin model at finite temperature using anisotropic lattices are presented. In both the large N approximation and numerical simulations using the Wolff cluster algorithm we find that the ratio of the symmetry restoration temperature TSR to the Higgs mass mH is independent of the anisotropy ξ. From the numerical simulations we obtain a lower bound of {T SR}/{m H}⋍ 0.58 ± 0.02 at a value for the Higgs mass m Ha s ⋍ 0.5 , which is lowered further by about 10% at m Ha s ⋍ 1 . Requiring certain timelike correlation functions to coincide with their spacelike counterparts, quantum and scaling corrections to the anisotropy are determined and are found to be small i.e., the anisotropy is found to be close to the ratio of spacelike and timelike lattice spacings.
High-order lattice Boltzmann models for wall-bounded flows at finite Knudsen numbers.
Feuchter, C; Schleifenbaum, W
2016-07-01
We analyze a large number of high-order discrete velocity models for solving the Boltzmann-Bhatnagar-Gross-Krook 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. Moreover, for small Knudsen numbers, the Knudsen layer behavior is recovered.
Improved Range Searching Lower Bounds
DEFF Research Database (Denmark)
Larsen, Kasper Green; Nguyen, Huy L.
2012-01-01
and Rosenberg's theorem), are also hard for dynamic range searching in the group model. This theorem allows us to reuse decades of research on range reporting lower bounds to immediately obtain a range of new group model lower bounds. Amongst others, this includes an improved lower bound for the fundamental...... problem of dynamic d-dimensional orthogonal range searching, stating that tqtu = Ω((lg n/lg lg n)d-1). Here tq denotes the query time and tu the update time of the data structure. This is an improvement of a lg1-δn factor over the recent lower bound of Larsen [FOCS'11], where δ>0 is a small constant......Table of Contents -------------------------------------------------------------------------------- In this paper we present a number of improved lower bounds for range searching in the pointer machine and the group model. In the pointer machine, we prove lower bounds for the approximate simplex...
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
Property Differencing for Incremental Checking
Yang, Guowei; Khurshid, Sarfraz; Person, Suzette; Rungta, Neha
2014-01-01
This paper introduces iProperty, a novel approach that facilitates incremental checking of programs based on a property di erencing technique. Speci cally, iProperty aims to reduce the cost of checking properties as they are initially developed and as they co-evolve with the program. The key novelty of iProperty is to compute the di erences between the new and old versions of expected properties to reduce the number and size of the properties that need to be checked during the initial development of the properties. Furthermore, property di erencing is used in synergy with program behavior di erencing techniques to optimize common regression scenarios, such as detecting regression errors or checking feature additions for conformance to new expected properties. Experimental results in the context of symbolic execution of Java programs annotated with properties written as assertions show the e ectiveness of iProperty in utilizing change information to enable more ecient checking.
Bound to bounce: a coupled scalar-tachyon model for a smooth cyclic universe
Li, Changhong; Cheung, Yeuk-Kwan E
2011-01-01
We introduce a string-inspired model for a cyclic universe, utilizing the tachyon-scalar coupling as well as contribution from curvature in a closed universe. The universe undergoes a locked inflation stage after each bounce. Cycles of inflation, decelerating expansion, followed by contraction are made possible because of the negative contribution to effective energy density by the curvature term. No ghosts are ever generated at any point in the entire evolution of the universe. The minimum size of the universe is nonzero for generic initial values of the scalar field. The Null, Weak, and Dominant Energy Conditions are not violated at the bounce points, contrary to many bounce models previously proposed. And the Strong Energy Condition is satisfied in periods with tachyon matter domination.
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.
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...
Regressions by leaps and bounds and biased estimation techniques in yield modeling
Marquina, N. E. (Principal Investigator)
1979-01-01
The author has identified the following significant results. It was observed that OLS was not adequate as an estimation procedure when the independent or regressor variables were involved in multicollinearities. This was shown to cause the presence of small eigenvalues of the extended correlation matrix A'A. It was demonstrated that the biased estimation techniques and the all-possible subset regression could help in finding a suitable model for predicting yield. Latent root regression was an excellent tool that found how many predictive and nonpredictive multicollinearities there were.
Institute of Scientific and Technical Information of China (English)
沈云付; 解晓方
2011-01-01
Petri网是一种应用非常广泛的建模工具,它能深刻、简洁地描述控制系统,特别是能较好地描述并发系统的结构,并能对系统的动态性质进行分析.在探讨了Petri网的模型检查的基础上,采用双DFS算法,对基于Petri网的模型检查的算法进行了改进,提出了针对Petri网的on-the-fly算法,同时给出了基于on-the-fly的Petri网模型检查的实现和测试,从而可以有效地对Petri网表示的系统模型进行模型检查.%Petri net is a very widely used modelling tool ,which can describe the control system in a profound and brief way.In particular,it can better describe the structure of concurrent system,and can analyse the dynamic property of a system.In this paper, based on the discussion of model checking of the Petri net,we adopt double DFS algorithm to improve the Petri net-based model checking algorithm,put forward the on-the-fly algorithm in light to the Petri net.Meanwhile,we also present the realisation and test of model checking of Petri net based on on-the-fly algorithm,so that the model checking on the system model expressed by Petri net can be applied effectively.
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.
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.
Directory of Open Access Journals (Sweden)
El Korso Mohammed
2011-01-01
Full Text Available Abstract The statistical resolution limit (SRL, which is defined as the minimal separation between parameters to allow a correct resolvability, is an important statistical tool to quantify the ultimate performance for parametric estimation problems. In this article, we generalize the concept of the SRL to the multidimensional SRL (MSRL applied to the multidimensional harmonic retrieval model. In this article, we derive the SRL for the so-called multidimensional harmonic retrieval model using a generalization of the previously introduced SRL concepts that we call multidimensional SRL (MSRL. We first derive the MSRL using an hypothesis test approach. This statistical test is shown to be asymptotically an uniformly most powerful test which is the strongest optimality statement that one could expect to obtain. Second, we link the proposed asymptotic MSRL based on the hypothesis test approach to a new extension of the SRL based on the Cramér-Rao Bound approach. Thus, a closed-form expression of the asymptotic MSRL is given and analyzed in the framework of the multidimensional harmonic retrieval model. Particularly, it is proved that the optimal MSRL is obtained for equi-powered sources and/or an equi-distributed number of sensors on each multi-way array.
Computing the bounds on the loss rates
Fourneau J.-M.; Mokdad L.; Pekergin N.
2002-01-01
We consider an example network where we compute the bounds on cell loss rates. The stochastic bounds for these loss rates using simple arguments lead to models easier to solve. We proved, using stochastic orders, that the loss rates of these easier models are really the bounds of our original model. For ill-balanced configurations these models give good estimates of loss rates.
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
Asynchronous Bounded Expected Delay Networks
Bakhshi, Rena; 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 contrast to ABD networks, ABE networks cannot be synchronised efficiently. At the example of an election algorithm, we show that the minimal assumptions of ABE networks are sufficient for the development of efficient algorithms. For anonymous, unidirectional ABE rings of known size N we devise a probabilistic leader election algorithm having average message and time complexity O(N).
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...
Transaction management with integrity checking
DEFF Research Database (Denmark)
Martinenghi, Davide; Christiansen, Henning
2005-01-01
, 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....
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.
A Lower Bound on $T_{SR}/{m_{\\rm H}}$ in the O(4) Model on Anisotropic Lattices
Gavai, R V; Karsch, Frithjof; Neuhaus, T; Plache, B
1992-01-01
Results of an investigation of the $O(4)$ spin model at finite temperature using anisotropic lattices are presented. In both the large $N$ approximation and numerical simulations using the Wolff cluster algorithm we find that the ratio of the symmetry restoration temperature $T_{\\rm SR}$ to the Higgs mass $m_{\\rm H}$ is independent of the anisotropy $\\xi$. From the numerical simulations we obtain a lower bound of $T_{\\rm SR} / m_{\\rm H} \\simeq 0.58 \\pm 0.02$ at a value for the Higgs mass $m_{\\rm H}a_s \\simeq 0.5$, which is lowered further by about $10\\%$ at $m_{\\rm H}a_s \\simeq 1$. Requiring certain timelike correlation functions to coincide with their spacelike counterparts, quantum and scaling corrections to the anisotropy are determined and are found to be small, i.e., the anisotropy is found to be close to the ratio of spacelike and timelike lattice spacings.
Automatization and familiarity in repeated checking
Dek, Eliane C P; van den Hout, Marcel A.; Giele, Catharina L.; Engelhard, Iris M.
2014-01-01
Repeated checking paradoxically increases memory uncertainty. This study investigated the underlying mechanism of this effect. We hypothesized that as a result of repeated checking, familiarity with stimuli increases, and automatization of the checking procedure occurs, which should result in decrea
Institute of Scientific and Technical Information of China (English)
王伟然; 范玉顺
2011-01-01
To meet the requirements for enterprise modeling of business operation of service oriented virtual enterprises, the service oriented virtual enterprise model ( SOVEM) is presented, and its consistency checking mechanism is given. On the basis of analyzing the business mode and characteristics of service oriented virtual enterprises, the conceptual model and the formalized definition of the SOVEM is proposed, and the modeling process and the mapping method for member enterprise models are analyzed. Then the consistency checking mechanism of the model is discussed, the consistency constrains of the model are defined, and the algorithms for consistency checking are proposed. The feasibility and effectiveness of the model and its consistency checking mechanism are proved through the implementation of a prototype modeling system and practical testing. The model focuses on the service oriented business mode, reflects the features of networked manufacturing, and provides consistent, total-range and multi-view integrated description for service oriented virtual enterprises, so as to support their construction and operation.%针对面向服务的虚拟企业业务运作对企业建模的需求,提出了面向服务的虚拟企业模型(SOVEM),并研究了其一致性检查机制.在分析面向服务的虚拟企业业务模式及其特点的基础上,提出了SOVEM的概念模型和形式化定义,讨论了其建模过程和成员企业模型映射方法,继而讨论了模型的一致性检查机制,定义了一致性约束并给出了模型验证算法,以保证模型的有效性,并且通过面向服务的虚拟企业建模原型系统的实现和实例检验验证了SOVEM及其一致性检查机制的可行性和有效性.该模型着眼于面向服务的业务模式,反映了网络化制造的特点,可为面向服务的虚拟企业提供一致的、全范围、多视图的集成化描述,以支持其构建和运行.
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
Tillman, Fred D.; Weaver, James W.
Migration of volatile chemicals from the subsurface into overlying buildings is known as vapor intrusion (VI). Under certain circumstances, people living in homes above contaminated soil or ground water may be exposed to harmful levels of these vapors. A popular VI screening-level algorithm widely used in the United States, Canada and the UK to assess this potential risk is the "Johnson and Ettinger" (J&E) model. Concern exists over using the J&E model for deciding whether or not further action is necessary at sites, as many parameters are not routinely measured (or are un-measurable). Using EPA-recommended ranges of parameter values for nine soil-type/source depth combinations, input parameter sets were identified that correspond to bounding results of the J&E model. The results established the existence of generic upper and lower bound parameter sets for maximum and minimum exposure for all soil types and depths investigated. Using the generic upper and lower bound parameter sets, an analysis can be performed that, given the limitations of the input ranges and the model, bounds the attenuation factor in a VI investigation.
Binswanger, J.
2008-01-01
This paper develops a new life cycle model that aims to describe the savings and asset allocation decisions of boundedly rational agents. The paper’s main theoretical contribution is the provision of a simple, tractable and parsimonious framework within which agents make forward looking decisions in
1983-12-01
by the fact that two distinct processes are involved, i.e. water flow and soil plasticity . 35 %. ........ - w 2 A L4 bL’ ,- - P7 Thus a certain amount...for *• MODCAL-Bounding Surface Soil Plasticity Model Calibration and Prediction -. *.Code (Volume II)," Civil Engineering Laboratory, Naval
1983-12-01
of appropriate time step lengths is complicated by the fact that two distinct processes are involved, i.e. water flow and soil plasticity . Thus a...1981. 9. DeNatale, 3.S., L.R. Herrmann, and Y.F. Dafalias, "User’s Manual for MODCAL-Bounding Surface Soil Plasticity Model Calibration and Prediction