Model Checking the Logic of Allen's Relations Meets and Started-by is P^NP-Complete

Directory of Open Access Journals (Sweden)

Laura Bozzelli

2016-09-01

Full Text Available In the plethora of fragments of Halpern and Shoham's modal logic of time intervals (HS, the logic AB of Allen's relations Meets and Started-by is at a central position. Statements that may be true at certain intervals, but at no sub-interval of them, such as accomplishments, as well as metric constraints about the length of intervals, that force, for instance, an interval to be at least (resp., at most, exactly k points long, can be expressed in AB. Moreover, over the linear order of the natural numbers N, it subsumes the (point-based logic LTL, as it can easily encode the next and until modalities. Finally, it is expressive enough to capture the ω-regular languages, that is, for each ω-regular expression R there exists an AB formula Φ such that the language defined by R coincides with the set of models of Φ over N. It has been shown that the satisfiability problem for AB over N is EXPSPACE-complete. Here we prove that, under the homogeneity assumption, its model checking problem is Δ^p_2 = P^NP-complete (for the sake of comparison, the model checking problem for full HS is EXPSPACE-hard, and the only known decision procedure is nonelementary. Moreover, we show that the modality for the Allen relation Met-by can be added to AB at no extra cost (AA'B is P^NP-complete as well.

Model Checking Structured Infinite Markov Chains

NARCIS (Netherlands)

Remke, Anne Katharina Ingrid

2008-01-01

In the past probabilistic model checking hast mostly been restricted to finite state models. This thesis explores the possibilities of model checking with continuous stochastic logic (CSL) on infinite-state Markov chains. We present an in-depth treatment of model checking algorithms for two special

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...... motivates why existing model checking technology should be supplemented by new techniques. It also contains a brief introduction to probability theory and concepts covered by the six papers making up the second part. The first two papers are concerned with developing online monitoring techniques...... systems. The fifth paper shows how stochastic hybrid automata are useful for modelling biological systems and the final paper is concerned with showing how statistical model checking is efficiently distributed. In parallel with developing the theory contained in the papers, a substantial part of this work...

Model Checking Markov Chains: Techniques and Tools

NARCIS (Netherlands)

Zapreev, I.S.

2008-01-01

This dissertation deals with four important aspects of model checking Markov chains: the development of efficient model-checking tools, the improvement of model-checking algorithms, the efficiency of the state-space reduction techniques, and the development of simulation-based model-checking

Model Checking Real-Time Systems

DEFF Research Database (Denmark)

Bouyer, Patricia; Fahrenberg, Uli; Larsen, Kim Guldstrand

2018-01-01

This chapter surveys timed automata as a formalism for model checking real-time systems. We begin with introducing the model, as an extension of finite-state automata with real-valued variables for measuring time. We then present the main model-checking results in this framework, and give a hint...

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 Discrete Duration Calculus

DEFF Research Database (Denmark)

Hansen, Michael Reichhardt

1994-01-01

can do model-checking. The subset we consider is expressive enough to formalize the requirements to the gas burner system given by A.P. Ravn (1993); but only for a discrete time domain. Model-checking is done by reducing the correctness problem ℳ|=𝒟 to the inclusion problem of regular...

Model Checking Markov Reward Models with Impulse Rewards

NARCIS (Netherlands)

Cloth, Lucia; Katoen, Joost-Pieter; Khattri, Maneesh; Pulungan, Reza; Bondavalli, Andrea; Haverkort, Boudewijn; Tang, Dong

This paper considers model checking of Markov reward models (MRMs), continuous-time Markov chains with state rewards as well as impulse rewards. The reward extension of the logic CSL (Continuous Stochastic Logic) is interpreted over such MRMs, and two numerical algorithms are provided to check the

Automata-Based Verification of Temporal Properties on Running Programs

Science.gov (United States)

Giannakopoulou, Dimitra; Havelund, Klaus; Lan, Sonie (Technical Monitor)

2001-01-01

This paper presents an approach to checking a running program against its Linear Temporal Logic (LTL) specifications. LTL is a widely used logic for expressing properties of programs viewed as sets of executions. Our approach consists of translating LTL formulae to finite-state automata, which are used as observers of the program behavior. The translation algorithm we propose modifies standard LTL to Buchi automata conversion techniques to generate automata that check finite program traces. The algorithm has been implemented in a tool, which has been integrated with the generic JPaX framework for runtime analysis of Java programs.

UTP and Temporal Logic Model Checking

Science.gov (United States)

Anderson, Hugh; Ciobanu, Gabriel; Freitas, Leo

In this paper we give an additional perspective to the formal verification of programs through temporal logic model checking, which uses Hoare and He Unifying Theories of Programming (UTP). Our perspective emphasizes the use of UTP designs, an alphabetised relational calculus expressed as a pre/post condition pair of relations, to verify state or temporal assertions about programs. The temporal model checking relation is derived from a satisfaction relation between the model and its properties. The contribution of this paper is that it shows a UTP perspective to temporal logic model checking. The approach includes the notion of efficiency found in traditional model checkers, which reduced a state explosion problem through the use of efficient data structures

Model Checking Infinite-State Markov Chains

NARCIS (Netherlands)

Remke, Anne Katharina Ingrid; Haverkort, Boudewijn R.H.M.; Cloth, L.

2004-01-01

In this paper algorithms for model checking CSL (continuous stochastic logic) against infinite-state continuous-time Markov chains of so-called quasi birth-death type are developed. In doing so we extend the applicability of CSL model checking beyond the recently proposed case for finite-state

Formal verification of automated teller machine systems using SPIN

Science.gov (United States)

Iqbal, Ikhwan Mohammad; Adzkiya, Dieky; Mukhlash, Imam

2017-08-01

Formal verification is a technique for ensuring the correctness of systems. This work focuses on verifying a model of the Automated Teller Machine (ATM) system against some specifications. We construct the model as a state transition diagram that is suitable for verification. The specifications are expressed as Linear Temporal Logic (LTL) formulas. We use Simple Promela Interpreter (SPIN) model checker to check whether the model satisfies the formula. This model checker accepts models written in Process Meta Language (PROMELA), and its specifications are specified in LTL formulas.

Coverage Metrics for Model Checking

Science.gov (United States)

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.

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....

Implementing Model-Check for Employee and Management Satisfaction

Science.gov (United States)

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.

Partial-order reduction for GPU model checking

NARCIS (Netherlands)

Neele, T.S.; Wijs, A.J.; Bošnački, D.; van de Pol, J.C.

2016-01-01

Model checking using GPUs has seen increased popularity over the last years. Because GPUs have a limited amount of memory, only small to medium-sized systems can be verified. For on-the-fly explicitstate model checking, we improve memory efficiency by applying partialorder reduction. We propose

Partial-Order Reduction for GPU Model Checking

NARCIS (Netherlands)

Neele, T.; Wijs, A.; Bosnacki, D.; van de Pol, Jan Cornelis; Artho, C; Legay, A.; Peled, D.

2016-01-01

Model checking using GPUs has seen increased popularity over the last years. Because GPUs have a limited amount of memory, only small to medium-sized systems can be verified. For on-the-fly explicit-state model checking, we improve memory efficiency by applying partial-order reduction. We propose

Model checking exact cost for attack scenarios

DEFF Research Database (Denmark)

Aslanyan, Zaruhi; Nielson, Flemming

2017-01-01

Attack trees constitute a powerful tool for modelling security threats. Many security analyses of attack trees can be seamlessly expressed as model checking of Markov Decision Processes obtained from the attack trees, thus reaping the benefits of a coherent framework and a mature tool support....... However, current model checking does not encompass the exact cost analysis of an attack, which is standard for attack trees. Our first contribution is the logic erPCTL with cost-related operators. The extended logic allows to analyse the probability of an event satisfying given cost bounds and to compute...... the exact cost of an event. Our second contribution is the model checking algorithm for erPCTL. Finally, we apply our framework to the analysis of attack trees....

Model Checking the Remote Agent Planner

Science.gov (United States)

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.

Multi-Valued Modal Fixed Point Logics for Model Checking

Science.gov (United States)

Nishizawa, Koki

In this paper, I will show how multi-valued logics are used for model checking. Model checking is an automatic technique to analyze correctness of hardware and software systems. A model checker is based on a temporal logic or a modal fixed point logic. That is to say, a system to be checked is formalized as a Kripke model, a property to be satisfied by the system is formalized as a temporal formula or a modal formula, and the model checker checks that the Kripke model satisfies the formula. Although most existing model checkers are based on 2-valued logics, recently new attempts have been made to extend the underlying logics of model checkers to multi-valued logics. I will summarize these new results.

Take the Reins on Model Quality with ModelCHECK and Gatekeeper

Science.gov (United States)

Jones, Corey

2012-01-01

Model quality and consistency has been an issue for us due to the diverse experience level and imaginative modeling techniques of our users. Fortunately, setting up ModelCHECK and Gatekeeper to enforce our best practices has helped greatly, but it wasn't easy. There were many challenges associated with setting up ModelCHECK and Gatekeeper including: limited documentation, restrictions within ModelCHECK, and resistance from end users. However, we consider ours a success story. In this presentation we will describe how we overcame these obstacles and present some of the details of how we configured them to work for us.

Strategic Planning through Model Checking of ATL Formulae

NARCIS (Netherlands)

Jamroga, W.J.; Rutkowski, L.; Siekmann, J.; Tadeusiewicz, R.; Zadeh, L.A.

2004-01-01

Model checking of temporal logic has already been proposed for automatic planning. In this paper, we introduce a simple adaptation of the ATL model checking algorithm that returns a strategy to achieve given goal. We point out that the algorithm generalizes minimaxing, and that ATL models generalize

Model Checking Temporal Logic Formulas Using Sticker Automata

Science.gov (United States)

Feng, Changwei; Wu, Huanmei

2017-01-01

As an important complex problem, the temporal logic model checking problem is still far from being fully resolved under the circumstance of DNA computing, especially Computation Tree Logic (CTL), Interval Temporal Logic (ITL), and Projection Temporal Logic (PTL), because there is still a lack of approaches for DNA model checking. To address this challenge, a model checking method is proposed for checking the basic formulas in the above three temporal logic types with DNA molecules. First, one-type single-stranded DNA molecules are employed to encode the Finite State Automaton (FSA) model of the given basic formula so that a sticker automaton is obtained. On the other hand, other single-stranded DNA molecules are employed to encode the given system model so that the input strings of the sticker automaton are obtained. Next, a series of biochemical reactions are conducted between the above two types of single-stranded DNA molecules. It can then be decided whether the system satisfies the formula or not. As a result, we have developed a DNA-based approach for checking all the basic formulas of CTL, ITL, and PTL. The simulated results demonstrate the effectiveness of the new method. PMID:29119114

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....

Discrete-time rewards model-checked

NARCIS (Netherlands)

Larsen, K.G.; Andova, S.; Niebert, Peter; Hermanns, H.; Katoen, Joost P.

2003-01-01

This paper presents a model-checking approach for analyzing discrete-time Markov reward models. For this purpose, the temporal logic probabilistic CTL is extended with reward constraints. This allows to formulate complex measures – involving expected as well as accumulated rewards – in a precise and

Symbolic Dependency Graphs for PCTL Model-Checking

DEFF Research Database (Denmark)

Mariegaard, Anders; Larsen, Kim Guldstrand

2017-01-01

We consider the problem of model-checking a subset of probabilistic CTL, interpreted over (discrete-time) Markov reward models, allowing the specification of lower bounds on the probability of the set of paths satisfying a cost-bounded path formula. We first consider a reduction to fixed-point co......We consider the problem of model-checking a subset of probabilistic CTL, interpreted over (discrete-time) Markov reward models, allowing the specification of lower bounds on the probability of the set of paths satisfying a cost-bounded path formula. We first consider a reduction to fixed...

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 mobile ad hoc networks

NARCIS (Netherlands)

Ghassemi, Fatemeh; Fokkink, Wan

2016-01-01

Modeling arbitrary connectivity changes within mobile ad hoc networks (MANETs) makes application of automated formal verification challenging. We use constrained labeled transition systems as a semantic model to represent mobility. To model check MANET protocols with respect to the underlying

Creating Büchi automata for multi-valued model checking

NARCIS (Netherlands)

Vijzelaar, Stefan J.J.; Fokkink, Wan J.

2017-01-01

In explicit state model checking of linear temporal logic properties, a Büchi automaton encodes a temporal property. It interleaves with a Kripke model to form a state space, which is searched for counterexamples. Multi-valued model checking considers additional truth values beyond the Boolean true

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...

The Origin of Sulfur Tolerance in Supported Platinum Catalysts: The Relationship between Structural and Catalytic Properties in Acidic and Alkaline Pt/LTL.

NARCIS (Netherlands)

Koningsberger, D.C.; Miller, J.T.

1996-01-01

The reactivity, structure, and sulfur tolerance is compared for platinum supported on acidic and alkaline LTL zeolite. In the absence of sulfur, EXAFS spectroscopy indicates that small metallic platinum particles of approximately 6 to 14 atoms/cluster are present. The TOF for neopentane

A voice-actuated wind tunnel model leak checking system

Science.gov (United States)

Larson, William E.

1989-01-01

A computer program has been developed that improves the efficiency of wind tunnel model leak checking. The program uses a voice recognition unit to relay a technician's commands to the computer. The computer, after receiving a command, can respond to the technician via a voice response unit. Information about the model pressure orifice being checked is displayed on a gas-plasma terminal. On command, the program records up to 30 seconds of pressure data. After the recording is complete, the raw data and a straight line fit of the data are plotted on the terminal. This allows the technician to make a decision on the integrity of the orifice being checked. All results of the leak check program are stored in a database file that can be listed on the line printer for record keeping purposes or displayed on the terminal to help the technician find unchecked orifices. This program allows one technician to check a model for leaks instead of the two or three previously required.

Efficient probabilistic model checking on general purpose graphic processors

NARCIS (Netherlands)

Bosnacki, D.; Edelkamp, S.; Sulewski, D.; Pasareanu, C.S.

2009-01-01

We present algorithms for parallel probabilistic model checking on general purpose graphic processing units (GPGPUs). For this purpose we exploit the fact that some of the basic algorithms for probabilistic model checking rely on matrix vector multiplication. Since this kind of linear algebraic

Schedulability of Herschel revisited using statistical model checking

DEFF Research Database (Denmark)

David, Alexandre; Larsen, Kim Guldstrand; Legay, Axel

2015-01-01

-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...... and blocking times of tasks. Consequently, the method may falsely declare deadline violations that will never occur during execution. This paper is a continuation of previous work of the authors in applying extended timed automata model checking (using the tool UPPAAL) to obtain more exact schedulability...... analysis, here in the presence of non-deterministic computation times of tasks given by intervals [BCET,WCET]. Computation intervals with preemptive schedulers make the schedulability analysis of the resulting task model undecidable. Our contribution is to propose a combination of model checking techniques...

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....

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...

From Transition Systems to Variability Models and from Lifted Model Checking Back to UPPAAL

DEFF Research Database (Denmark)

Dimovski, Aleksandar; Wasowski, Andrzej

2017-01-01

efficient lifted (family-based) model checking for real-time variability models. This reduces the cost of maintaining specialized family-based real-time model checkers. Real-time variability models can be model checked using the standard UPPAAL. We have implemented abstractions as syntactic source...

Automatic Generation of Minimal Cut Sets

Directory of Open Access Journals (Sweden)

Sentot Kromodimoeljo

2015-06-01

Full Text Available A cut set is a collection of component failure modes that could lead to a system failure. Cut Set Analysis (CSA is applied to critical systems to identify and rank system vulnerabilities at design time. Model checking tools have been used to automate the generation of minimal cut sets but are generally based on checking reachability of system failure states. This paper describes a new approach to CSA using a Linear Temporal Logic (LTL model checker called BT Analyser that supports the generation of multiple counterexamples. The approach enables a broader class of system failures to be analysed, by generalising from failure state formulae to failure behaviours expressed in LTL. The traditional approach to CSA using model checking requires the model or system failure to be modified, usually by hand, to eliminate already-discovered cut sets, and the model checker to be rerun, at each step. By contrast, the new approach works incrementally and fully automatically, thereby removing the tedious and error-prone manual process and resulting in significantly reduced computation time. This in turn enables larger models to be checked. Two different strategies for using BT Analyser for CSA are presented. There is generally no single best strategy for model checking: their relative efficiency depends on the model and property being analysed. Comparative results are given for the A320 hydraulics case study in the Behavior Tree modelling language.

Performability assessment by model checking of Markov reward models

NARCIS (Netherlands)

Baier, Christel; Cloth, L.; Haverkort, Boudewijn R.H.M.; Hermanns, H.; Katoen, Joost P.

2010-01-01

This paper describes efficient procedures for model checking Markov reward models, that allow us to evaluate, among others, the performability of computer-communication systems. We present the logic CSRL (Continuous Stochastic Reward Logic) to specify performability measures. It provides flexibility

Development of a butterfly check valve model under natural circulation conditions

International Nuclear Information System (INIS)

Rao, Yuxian; Yu, Lei; Fu, Shengwei; Zhang, Fan

2015-01-01

Highlights: • Bases on Lim’s swing check valve model, a butterfly check valve model was developed. • The method to quantify the friction torque T F in Li’s model was corrected. • The developed model was implemented into the RELAP5 code and verified. - Abstract: A butterfly check valve is widely used to prevent a reverse flow in the pipe lines of a marine nuclear power plant. Under some conditions, the natural circulation conditions in particular, the fluid velocity through the butterfly check valve might become too low to hold the valve disk fully open, thereby the flow resistance of the butterfly check valve varies with the location of the valve disk and as a result the fluid flow is significantly affected by the dynamic motion of the valve disk. Simulation of a pipe line that includes some butterfly check valves, especially under natural circulation conditions, is thus complicated. This paper focuses on the development of a butterfly check valve model to enhance the capability of the thermal–hydraulic system code and the developed model is implemented into the RELAP5 code. Both steady-state calculations and transient calculations were carried out for the primary loop system of a marine nuclear power plant and the calculation results are compared with the experimental data for verification purpose. The simulation results show an agreement with the experimental data

CheckMATE 2: From the model to the limit

Science.gov (United States)

Dercks, Daniel; Desai, Nishita; Kim, Jong Soo; Rolbiecki, Krzysztof; Tattersall, Jamie; Weber, Torsten

2017-12-01

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 MadGraph5_aMC@NLO 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.

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...

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...

Slicing AADL specifications for model checking

NARCIS (Netherlands)

Odenbrett, M.R.; Nguyen, V.Y.; Noll, T.

2010-01-01

To combat the state-space explosion problem in model checking larger systems, abstraction techniques can be employed. Here, methods that operate on the system specification before constructing its state space are preferable to those that try to minimize the resulting transition system as they

Efficient family-based model checking via variability abstractions

DEFF Research Database (Denmark)

Dimovski, Aleksandar; Al-Sibahi, Ahmad Salim; Brabrand, Claus

2016-01-01

with the abstract model checking of the concrete high-level variational model. This allows the use of Spin with all its accumulated optimizations for efficient verification of variational models without any knowledge about variability. We have implemented the transformations in a prototype tool, and we illustrate......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...

Towards Model Checking a Spi-Calculus Dialect

NARCIS (Netherlands)

Gnesi, S.; Latella, D.; Lenzini, Gabriele

We present a model checking framework for a spi-calculus dialect which uses a linear time temporal logic for expressing security properties. We have provided our spi-calculus dialect, called SPID, with a semantics based on labeled transition systems (LTS), where the intruder is modeled in the

PVeStA: A Parallel Statistical Model Checking and Quantitative Analysis Tool

KAUST Repository

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.

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...... probability can then be approximated in polynomial time (using uniformization). This makes the present work the centerpiece of a broadly applicable full CSL model checker. Recently, the decision algorithm by Aziz et al. was shown to be incorrect in general. In fact, it works only for stratified CTMCs...

WCET Analysis of ARM Processors using Real-Time Model Checking

DEFF Research Database (Denmark)

Toft, Martin; Olesen, Mads Christian; Dalsgaard, Andreas

2009-01-01

This paper presents a flexible method that utilises real-time model checking to determine safe and sharp WCETs for processes running on hardware platforms featuring pipelining and caching.......This paper presents a flexible method that utilises real-time model checking to determine safe and sharp WCETs for processes running on hardware platforms featuring pipelining and caching....

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 a non-convex set needing sets of DBMs for representation. Our subtraction algorithms are efficient in the sense that the number of generated DBMs is significantly reduced compared to a naive algorithm. The overhead in time is compensated by the gain from reducing the number of resulting DBMs since...... this number affects the performance of symbolic model-checking. The uses of the DBM subtraction operation extend beyond timed automata with priorities. It is also useful for allowing guards on transitions with urgent actions, deadlock checking, and timed games....

Integrating model checking with HiP-HOPS in model-based safety analysis

International Nuclear Information System (INIS)

Sharvia, Septavera; Papadopoulos, Yiannis

2015-01-01

The ability to perform an effective and robust safety analysis on the design of modern safety–critical systems is crucial. Model-based safety analysis (MBSA) has been introduced in recent years to support the assessment of complex system design by focusing on the system model as the central artefact, and by automating the synthesis and analysis of failure-extended models. Model checking and failure logic synthesis and analysis (FLSA) are two prominent MBSA paradigms. Extensive research has placed emphasis on the development of these techniques, but discussion on their integration remains limited. In this paper, we propose a technique in which model checking and Hierarchically Performed Hazard Origin and Propagation Studies (HiP-HOPS) – an advanced FLSA technique – can be applied synergistically with benefit for the MBSA process. The application of the technique is illustrated through an example of a brake-by-wire system. - Highlights: • We propose technique to integrate HiP-HOPS and model checking. • State machines can be systematically constructed from HiP-HOPS. • The strengths of different MBSA techniques are combined. • Demonstrated through modeling and analysis of brake-by-wire system. • Root cause analysis is automated and system dynamic behaviors analyzed and verified

Model-checking techniques based on cumulative residuals.

Science.gov (United States)

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.

Behavioral Consistency of C and Verilog Programs Using Bounded Model Checking

National Research Council Canada - National Science Library

Clarke, Edmund; Kroening, Daniel; Yorav, Karen

2003-01-01

.... We describe experimental results on various reactive present an algorithm that checks behavioral consistency between an ANSI-C program and a circuit given in Verilog using Bounded Model Checking...

Model Checking - Automated Verification of Computational Systems

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 7. Model Checking - Automated Verification of Computational Systems. Madhavan Mukund. General Article Volume 14 Issue 7 July 2009 pp 667-681. Fulltext. Click here to view fulltext PDF. Permanent link:

Consistency checks in beam emission modeling for neutral beam injectors

International Nuclear Information System (INIS)

Punyapu, Bharathi; Vattipalle, Prahlad; Sharma, Sanjeev Kumar; Baruah, Ujjwal Kumar; Crowley, Brendan

2015-01-01

In positive neutral beam systems, the beam parameters such as ion species fractions, power fractions and beam divergence are routinely measured using Doppler shifted beam emission spectrum. The accuracy with which these parameters are estimated depend on the accuracy of the atomic modeling involved in these estimations. In this work, an effective procedure to check the consistency of the beam emission modeling in neutral beam injectors is proposed. As a first consistency check, at a constant beam voltage and current, the intensity of the beam emission spectrum is measured by varying the pressure in the neutralizer. Then, the scaling of measured intensity of un-shifted (target) and Doppler shifted intensities (projectile) of the beam emission spectrum at these pressure values are studied. If the un-shifted component scales with pressure, then the intensity of this component will be used as a second consistency check on the beam emission modeling. As a further check, the modeled beam fractions and emission cross sections of projectile and target are used to predict the intensity of the un-shifted component and then compared with the value of measured target intensity. An agreement between the predicted and measured target intensities provide the degree of discrepancy in the beam emission modeling. In order to test this methodology, a systematic analysis of Doppler shift spectroscopy data obtained on the JET neutral beam test stand data was carried out

Model checking the HAVi leader election protocol

NARCIS (Netherlands)

J.M.T. Romijn (Judi)

1999-01-01

textabstractThe 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

Verifying large SDL-specifications using model checking

NARCIS (Netherlands)

Sidorova, N.; Steffen, M.; Reed, R.; Reed, J.

2001-01-01

In this paper we propose a methodology for model-checking based verification of large SDL specifications. The methodology is illustrated by a case study of an industrial medium-access protocol for wireless ATM. To cope with the state space explosion, the verification exploits the layered and modular

Model checking optimal finite-horizon control for probabilistic gene regulatory networks.

Science.gov (United States)

Wei, Ou; Guo, Zonghao; Niu, Yun; Liao, Wenyuan

2017-12-14

Probabilistic Boolean networks (PBNs) have been proposed for analyzing external control in gene regulatory networks with incorporation of uncertainty. A context-sensitive PBN with perturbation (CS-PBNp), extending a PBN with context-sensitivity to reflect the inherent biological stability and random perturbations to express the impact of external stimuli, is considered to be more suitable for modeling small biological systems intervened by conditions from the outside. In this paper, we apply probabilistic model checking, a formal verification technique, to optimal control for a CS-PBNp that minimizes the expected cost over a finite control horizon. We first describe a procedure of modeling a CS-PBNp using the language provided by a widely used probabilistic model checker PRISM. We then analyze the reward-based temporal properties and the computation in probabilistic model checking; based on the analysis, we provide a method to formulate the optimal control problem as minimum reachability reward properties. Furthermore, we incorporate control and state cost information into the PRISM code of a CS-PBNp such that automated model checking a minimum reachability reward property on the code gives the solution to the optimal control problem. We conduct experiments on two examples, an apoptosis network and a WNT5A network. Preliminary experiment results show the feasibility and effectiveness of our approach. The approach based on probabilistic model checking for optimal control avoids explicit computation of large-size state transition relations associated with PBNs. It enables a natural depiction of the dynamics of gene regulatory networks, and provides a canonical form to formulate optimal control problems using temporal properties that can be automated solved by leveraging the analysis power of underlying model checking engines. This work will be helpful for further utilization of the advances in formal verification techniques in system biology.

Mixed Portmanteau Test for Diagnostic Checking of Time Series Models

Directory of Open Access Journals (Sweden)

Sohail Chand

2014-01-01

Full Text Available Model criticism is an important stage of model building and thus goodness of fit tests provides a set of tools for diagnostic checking of the fitted model. Several tests are suggested in literature for diagnostic checking. These tests use autocorrelation or partial autocorrelation in the residuals to criticize the adequacy of fitted model. The main idea underlying these portmanteau tests is to identify if there is any dependence structure which is yet unexplained by the fitted model. In this paper, we suggest mixed portmanteau tests based on autocorrelation and partial autocorrelation functions of the residuals. We derived the asymptotic distribution of the mixture test and studied its size and power using Monte Carlo simulations.

Model Checking as Static Analysis

DEFF Research Database (Denmark)

Zhang, Fuyuan

fairness problems can be encoded into ALFP as well. To deal with multi-valued model checking problems, we have proposed multivalued ALFP. A Moore Family result for multi-valued ALFP is also established, which ensures the existence and uniqueness of the least model. When the truth values in multi-valued...... of states satisfying a CTL formula can be characterized as the least model of ALFP clauses specifying this CTL formula. The existence of the least model of ALFP clauses is ensured by the Moore Family property of ALFP. Then, we take fairness assumptions in CTL into consideration and have shown that CTL...... ALFP constitute a nite distributive complete lattice, multi-valued ALFP can be reduced to two-valued ALFP. This result enables to implement a solver for multi-valued ALFP by reusing existing solvers for twovalued ALFP. Our ALFP-based technique developed for the two-valued CTL naturally generalizes...

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.

Model checking methodology for large systems, faults and asynchronous behaviour. SARANA 2011 work report

International Nuclear Information System (INIS)

Lahtinen, J.; Launiainen, T.; Heljanko, K.; Ropponen, J.

2012-01-01

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.)

Model checking methodology for large systems, faults and asynchronous behaviour. SARANA 2011 work report

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.)

modelling of queuing process at airport check-in system

African Journals Online (AJOL)

HOD

Key words: Airport check-in system, discrete time events, analytical models, simulation model, SimEvents toolbox. 1. ..... [6] Gross, D. and Harris, C. M. Fundamentals of. Queueing ... [11] Manataki I. E. and Zogra os K. G. “A Generic. System ...

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...

Using Canonical Forms for Isomorphism Reduction in Graph-based Model Checking

NARCIS (Netherlands)

Kant, Gijs

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

Variability-Specific Abstraction Refinement for Family-Based Model Checking

DEFF Research Database (Denmark)

Dimovski, Aleksandar; Wasowski, Andrzej

2017-01-01

and property, while the number of possible scenarios is very large. In this work, we present an automatic iterative abstraction refinement procedure for family-based model checking. We use Craig interpolation to refine abstract variational models based on the obtained spurious counterexamples (traces...

State Space Reduction for Model Checking Agent Programs

NARCIS (Netherlands)

S.-S.T.Q. Jongmans (Sung-Shik); K.V. Hindriks; M.B. van Riemsdijk; L. Dennis; O. Boissier; R.H. Bordini (Rafael)

2012-01-01

htmlabstractState space reduction techniques have been developed to increase the efficiency of model checking in the context of imperative programming languages. Unfortunately, these techniques cannot straightforwardly be applied to agents: the nature of states in the two programming paradigms

A Novel Method to Verify Multilevel Computational Models of Biological Systems Using Multiscale Spatio-Temporal Meta Model Checking.

Science.gov (United States)

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

Query Language for Location-Based Services: A Model Checking Approach

Science.gov (United States)

Hoareau, Christian; Satoh, Ichiro

We present a model checking approach to the rationale, implementation, and applications of a query language for location-based services. Such query mechanisms are necessary so that users, objects, and/or services can effectively benefit from the location-awareness of their surrounding environment. The underlying data model is founded on a symbolic model of space organized in a tree structure. Once extended to a semantic model for modal logic, we regard location query processing as a model checking problem, and thus define location queries as hybrid logicbased formulas. Our approach is unique to existing research because it explores the connection between location models and query processing in ubiquitous computing systems, relies on a sound theoretical basis, and provides modal logic-based query mechanisms for expressive searches over a decentralized data structure. A prototype implementation is also presented and will be discussed.

Recent advances in importance sampling for statistical model checking

NARCIS (Netherlands)

Reijsbergen, D.P.; de Boer, Pieter-Tjerk; Scheinhardt, Willem R.W.; Haverkort, Boudewijn R.H.M.

2013-01-01

In the following work we present an overview of recent advances in rare event simulation for model checking made at the University of Twente. The overview is divided into the several model classes for which we propose algorithms, namely multicomponent systems, Markov chains and stochastic Petri

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.

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....

On Verification of PLC-Programs Written in the LD-Language

Directory of Open Access Journals (Sweden)

E. V. Kuzmin

2012-01-01

Full Text Available We discuss some questions connected with the construction of a technology of analysing correctness of Programmable Logic Controller programs. We consider an example of modeling and automated verification of PLC-programs written in the Ladder Diagram language (including timed function blocks of the IEC 61131-3 standard. We use the Cadence SMV for symbolic model checking. Program properties are written in the linear-time temporal logic LTL.

Quantitative Analysis of Probabilistic Models of Software Product Lines with Statistical Model Checking

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 pa...

Application of Model-Checking Technology to Controller Synthesis

DEFF Research Database (Denmark)

David, Alexandre; Grunnet, Jacob Deleuran; Jessen, Jan Jacob

2011-01-01

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 with...

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.

Checking Fine and Gray subdistribution hazards model with cumulative sums of residuals

DEFF Research Database (Denmark)

Li, Jianing; Scheike, Thomas; Zhang, Mei Jie

2015-01-01

Recently, Fine and Gray (J Am Stat Assoc 94:496–509, 1999) proposed a semi-parametric proportional regression model for the subdistribution hazard function which has been used extensively for analyzing competing risks data. However, failure of model adequacy could lead to severe bias in parameter...... estimation, and only a limited contribution has been made to check the model assumptions. In this paper, we present a class of analytical methods and graphical approaches for checking the assumptions of Fine and Gray’s model. The proposed goodness-of-fit test procedures are based on the cumulative sums...

Model checking software for phylogenetic trees using distribution and database methods

Directory of Open Access Journals (Sweden)

Requeno José Ignacio

2013-12-01

Full Text Available Model checking, a generic and formal paradigm stemming from computer science based on temporal logics, has been proposed for the study of biological properties that emerge from the labeling of the states defined over the phylogenetic tree. This strategy allows us to use generic software tools already present in the industry. However, the performance of traditional model checking is penalized when scaling the system for large phylogenies. To this end, two strategies are presented here. The first one consists of partitioning the phylogenetic tree into a set of subgraphs each one representing a subproblem to be verified so as to speed up the computation time and distribute the memory consumption. The second strategy is based on uncoupling the information associated to each state of the phylogenetic tree (mainly, the DNA sequence and exporting it to an external tool for the management of large information systems. The integration of all these approaches outperforms the results of monolithic model checking and helps us to execute the verification of properties in a real phylogenetic tree.

Phase Two Feasibility Study for Software Safety Requirements Analysis Using Model Checking

Science.gov (United States)

Turgeon, Gregory; Price, Petra

2010-01-01

A feasibility study was performed on a representative aerospace system to determine the following: (1) the benefits and limitations to using SCADE , a commercially available tool for model checking, in comparison to using a proprietary tool that was studied previously [1] and (2) metrics for performing the model checking and for assessing the findings. This study was performed independently of the development task by a group unfamiliar with the system, providing a fresh, external perspective free from development bias.

Towards the Formal Verification of a Distributed Real-Time Automotive System

Science.gov (United States)

Endres, Erik; Mueller, Christian; Shadrin, Andrey; Tverdyshev, Sergey

2010-01-01

We present the status of a project which aims at building, formally and pervasively verifying a distributed automotive system. The target system is a gate-level model which consists of several interconnected electronic control units with independent clocks. This model is verified against the specification as seen by a system programmer. The automotive system is implemented on several FPGA boards. The pervasive verification is carried out using combination of interactive theorem proving (Isabelle/HOL) and model checking (LTL).

Model checking as an aid to procedure design

International Nuclear Information System (INIS)

Zhang, Wenhu

2001-01-01

The OECD Halden Reactor Project has been actively working on computer assisted operating procedures for many years. The objective of the research has been to provide computerised assistance for procedure design, verification and validation, implementation and maintenance. For the verification purpose, the application of formal methods has been considered in several reports. The recent formal verification activity conducted at the Halden Project is based on using model checking to the verification of procedures. This report presents verification approaches based on different model checking techniques and tools for the formalization and verification of operating procedures. Possible problems and relative merits of the different approaches are discussed. A case study of one of the approaches is presented to show the practical application of formal verification. Application of formal verification in the traditional procedure design process can reduce the human resources involved in reviews and simulations, and hence reduce the cost of verification and validation. A discussion of the integration of the formal verification with the traditional procedure design process is given at the end of this report. (Author)

Methods to model-check parallel systems software

International Nuclear Information System (INIS)

Matlin, O. S.; McCune, W.; Lusk, E.

2003-01-01

We report on an effort to develop methodologies for formal verification of parts of the Multi-Purpose Daemon (MPD) parallel process management system. MPD is a distributed collection of communicating processes. While the individual components of the collection execute simple algorithms, their interaction leads to unexpected errors that are difficult to uncover by conventional means. Two verification approaches are discussed here: the standard model checking approach using the software model checker SPIN and the nonstandard use of a general-purpose first-order resolution-style theorem prover OTTER to conduct the traditional state space exploration. We compare modeling methodology and analyze performance and scalability of the two methods with respect to verification of MPD

Symbolic Game Semantics for Model Checking Program Families

DEFF Research Database (Denmark)

Dimovski, Aleksandar

2016-01-01

represent program families with infinite integers as so-called (finite-state) featured symbolic automata. Specifically designed model checking algorithms are then employed to verify safety of all programs from a family at once and pinpoint those programs that are unsafe (respectively, safe). We present...... a prototype tool implementing this approach, and we illustrate it with several examples....

Model checking: one can do much more than you think!

NARCIS (Netherlands)

Katoen, Joost P.

2012-01-01

Model checking is an automated verification technique that actively is applied to find bugs in hardware and software designs. Companies like IBM and Cadence developed their in-house model checkers, and acted as driving forces behind the design of the IEEE-standardized temporal logic PSL. On the

Bayesian inference with information content model check for Langevin equations

DEFF Research Database (Denmark)

Krog, Jens F. C.; Lomholt, Michael Andersen

2017-01-01

The Bayesian data analysis framework has been proven to be a systematic and effective method of parameter inference and model selection for stochastic processes. In this work we introduce an information content model check which may serve as a goodness-of-fit, like the chi-square procedure...

Requirements-level semantics and model checking of object-oriented statecharts

NARCIS (Netherlands)

Eshuis, H.; Jansen, D.N.; Wieringa, Roelf J.

2002-01-01

In this paper we define a requirements-level execution semantics for object-oriented statecharts and show how properties of a system specified by these statecharts can be model checked using tool support for model checkers. Our execution semantics is requirements-level because it uses the perfect

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...

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.

PENERAPAN MODEL PEMBELAJARAN KOOPERATIF TIPE PAIR CHECKS PEMECAHAN MASALAH UNTUK MENINGKATKAN SOCIAL SKILL SISWA

Directory of Open Access Journals (Sweden)

R. Lestari

2012-07-01

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 student’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 student’s social skill and students’ achievement from cycle one to two. It is concluded that cooperative learning model-pair checks problem solving type can enhance student’s social skills

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...

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...... with good test strength are explained. Interlocking systems represent just one class of many others, where concrete system instances are created from generic representations, using configuration data for determining the behaviour of the instances. We explain how the systematic transition from generic...... to concrete instances in the development path is complemented by associated transitions in the verification and testing paths....

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....../Off and bidirectional check valves. Based on the analysis it is found that the energy production may be slightly improved by using bidirectional check valves as compared to on/off valves, due to a decrease in switching losses. Furthermore a reduction in high flow peaks are realised. The downside being increased...

Testing Linear Temporal Logic Formulae on Finite Execution Traces

Science.gov (United States)

Havelund, Klaus; Rosu, Grigore; Norvig, Peter (Technical Monitor)

2001-01-01

We present an algorithm for efficiently testing Linear Temporal Logic (LTL) formulae on finite execution traces. The standard models of LTL are infinite traces, reflecting the behavior of reactive and concurrent systems which conceptually may be continuously alive. In most past applications of LTL. theorem provers and model checkers have been used to formally prove that down-scaled models satisfy such LTL specifications. Our goal is instead to use LTL for up-scaled testing of real software applications. Such tests correspond to analyzing the conformance of finite traces against LTL formulae. We first describe what it means for a finite trace to satisfy an LTL property. We then suggest an optimized algorithm based on transforming LTL formulae. The work is done using the Maude rewriting system. which turns out to provide a perfect notation and an efficient rewriting engine for performing these experiments.

Model-Checking Driven Design of QoS-Based Routing Protocol for Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Zhi Chen

2015-01-01

Full Text Available Accurate and reliable routing protocols with Quality of Service (QoS support determine the mission-critical application efficiency in WSNs. This paper proposes a model-checking design driven framework for designing the QoS-based routing protocols of WSNs, which involves the light-weight design process, the timed automata model, and the alternative QoS verification properties. The accurate feedback of continually model checking in the iterative design process effectively stimulates the parameter tuning of the protocols. We demonstrate the straightforward and modular characteristics of the proposed framework in designing a prototype QoS-based routing protocol. The prototype study shows that the model-checking design framework may complement other design methods and ensure the QoS implementation of the QoS-based routing protocol design for WSNs.

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.

Analysis of DIRAC's behavior using model checking with process algebra

CERN Document Server

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...

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...

Optimizing ZigBee Security using Stochastic Model Checking

DEFF Research Database (Denmark)

Yuksel, Ender; Nielson, Hanne Riis; Nielson, Flemming

, 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......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...

On-the-fly confluence detection for statistical model checking (extended version)

NARCIS (Netherlands)

Hartmanns, Arnd; Timmer, Mark

Statistical model checking is an analysis method that circumvents the state space explosion problem in model-based verification by combining probabilistic simulation with statistical methods that provide clear error bounds. As a simulation-based technique, it can only provide sound results if the

Model-checking statistique pour la vérification de véhicules autonomes

OpenAIRE

Barbot , Benoît; Bérard , Béatrice; Duplouy , Yann; Haddad , Serge

2017-01-01

National audience; We present an application of statistical model-checking to the verification of an autonomous vehicle controller. Our goal is to check safety properties in various traffic situations. More specifically, we focus on a traffic jam situation. The controller is specified by a C++ program. Using sensors, it registers positions and velocities of nearby vehicles and modifies the position and velocity of the controlled vehicle to avoid collisions. We model the environment using a st...

Modeling and analysis of cell membrane systems with probabilistic model checking

Science.gov (United States)

2011-01-01

Background Recently there has been a growing interest in the application of Probabilistic Model Checking (PMC) for the formal specification of biological systems. PMC is able to exhaustively explore all states of a stochastic model and can provide valuable insight into its behavior which are more difficult to see using only traditional methods for system analysis such as deterministic and stochastic simulation. In this work we propose a stochastic modeling for the description and analysis of sodium-potassium exchange pump. The sodium-potassium pump is a membrane transport system presents in all animal cell and capable of moving sodium and potassium ions against their concentration gradient. Results We present a quantitative formal specification of the pump mechanism in the PRISM language, taking into consideration a discrete chemistry approach and the Law of Mass Action aspects. We also present an analysis of the system using quantitative properties in order to verify the pump reversibility and understand the pump behavior using trend labels for the transition rates of the pump reactions. Conclusions Probabilistic model checking can be used along with other well established approaches such as simulation and differential equations to better understand pump behavior. Using PMC we can determine if specific events happen such as the potassium outside the cell ends in all model traces. We can also have a more detailed perspective on its behavior such as determining its reversibility and why its normal operation becomes slow over time. This knowledge can be used to direct experimental research and make it more efficient, leading to faster and more accurate scientific discoveries. PMID:22369714

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 veri...

Analysis of an emergency diesel generator control system by compositional model checking. MODSAFE 2010 work report

International Nuclear Information System (INIS)

Lahtinen, J.; Bjoerkman, K.; Valkonen, J.; Frits, J.; Niemelae, I.

2010-12-01

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.)

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.

PENERAPAN MODEL PEMBELAJARAN KOOPERATIF TIPE PAIR CHECKS PEMECAHAN MASALAH UNTUK MENINGKATKAN SOCIAL SKILL SISWA

OpenAIRE

R. Lestari; S. Linuwih

2012-01-01

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...

Petri Net and Probabilistic Model Checking Based Approach for the Modelling, Simulation and Verification of Internet Worm Propagation.

Directory of Open Access Journals (Sweden)

Misbah Razzaq

Full Text Available Internet worms are analogous to biological viruses since they can infect a host and have the ability to propagate through a chosen medium. To prevent the spread of a worm or to grasp how to regulate a prevailing worm, compartmental models are commonly used as a means to examine and understand the patterns and mechanisms of a worm spread. However, one of the greatest challenge is to produce methods to verify and validate the behavioural properties of a compartmental model. This is why in this study we suggest a framework based on Petri Nets and Model Checking through which we can meticulously examine and validate these models. We investigate Susceptible-Exposed-Infectious-Recovered (SEIR model and propose a new model Susceptible-Exposed-Infectious-Recovered-Delayed-Quarantined (Susceptible/Recovered (SEIDQR(S/I along with hybrid quarantine strategy, which is then constructed and analysed using Stochastic Petri Nets and Continuous Time Markov Chain. The analysis shows that the hybrid quarantine strategy is extremely effective in reducing the risk of propagating the worm. Through Model Checking, we gained insight into the functionality of compartmental models. Model Checking results validate simulation ones well, which fully support the proposed framework.

Design of Installing Check Dam Using RAMMS Model in Seorak National Park of South Korea

Science.gov (United States)

Jun, K.; Tak, W.; JUN, B. H.; Lee, H. J.; KIM, S. D.

2016-12-01

Design of Installing Check Dam Using RAMMS Model in Seorak National Park of South Korea Kye-Won Jun*, Won-Jun Tak*, Byong-Hee Jun**, Ho-Jin Lee***, Soung-Doug Kim* *Graduate School of Disaster Prevention, Kangwon National University, 346 Joogang-ro, Samcheok-si, Gangwon-do, Korea **School of Fire and Disaster Protection, Kangwon National University, 346 Joogang-ro, Samcheok-si, Gangwon-do, Korea ***School of Civil Engineering, Chungbuk National University, 1 Chungdae-ro, Seowon-gu, Cheongju, Korea Abstract As more than 64% of the land in South Korea is mountainous area, so many regions in South Korea are exposed to the danger of landslide and debris flow. So it is important to understand the behavior of debris flow in mountainous terrains, the various methods and models are being presented and developed based on the mathematical concept. The purpose of this study is to investigate the regions that experienced the debris flow due to typhoon called Ewiniar and to perform numerical modeling to design and layout of the Check dam for reducing the damage by the debris flow. For the performance of numerical modeling, on-site measurement of the research area was conducted including: topographic investigation, research on bridges in the downstream, and precision LiDAR 3D scanning for composed basic data of numerical modeling. The numerical simulation of this study was performed using RAMMS (Rapid Mass Movements Simulation) model for the analysis of the debris flow. This model applied to the conditions of the Check dam which was installed in the upstream, midstream, and downstream. Considering the reduction effect of debris flow, the expansion of debris flow, and the influence on the bridges in the downstream, proper location of the Check dam was designated. The result of present numerical model showed that when the Check dam was installed in the downstream section, 50 m above the bridge, the reduction effect of the debris flow was higher compared to when the Check dam were

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

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...... 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...

Deterministic Compilation of Temporal Safety Properties in Explicit State Model Checking

Data.gov (United States)

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...

Logic Model Checking of Unintended Acceleration Claims in Toyota Vehicles

Science.gov (United States)

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

Discounted Duration Calculus

DEFF Research Database (Denmark)

Ody, Heinrich; Fränzle, Martin; Hansen, Michael Reichhardt

2016-01-01

To formally reason about the temporal quality of systems discounting was introduced to CTL and LTL. However, these logic are discrete and they cannot express duration properties. In this work we introduce discounting for a variant of Duration Calculus. We prove decidability of model checking...... for a useful fragment of discounted Duration Calculus formulas on timed automata under mild assumptions. Further, we provide an extensive example to show the usefulness of the fragment....

Model Checking JAVA Programs Using Java Pathfinder

Science.gov (United States)

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.

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

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...

Sound statistical model checking for MDP using partial order and confluence reduction

NARCIS (Netherlands)

Hartmanns, Arnd; Timmer, Mark

Statistical model checking (SMC) is an analysis method that circumvents the state space explosion problem in model-based verification by combining probabilistic simulation with statistical methods that provide clear error bounds. As a simulation-based technique, it can in general only provide sound

Approximate Model Checking of PCTL Involving Unbounded Path Properties

Science.gov (United States)

Basu, Samik; Ghosh, Arka P.; He, Ru

We study the problem of applying statistical methods for approximate model checking of probabilistic systems against properties encoded as PCTL formulas. Such approximate methods have been proposed primarily to deal with state-space explosion that makes the exact model checking by numerical methods practically infeasible for large systems. However, the existing statistical methods either consider a restricted subset of PCTL, specifically, the subset that can only express bounded until properties; or rely on user-specified finite bound on the sample path length. We propose a new method that does not have such restrictions and can be effectively used to reason about unbounded until properties. We approximate probabilistic characteristics of an unbounded until property by that of a bounded until property for a suitably chosen value of the bound. In essence, our method is a two-phase process: (a) the first phase is concerned with identifying the bound k 0; (b) the second phase computes the probability of satisfying the k 0-bounded until property as an estimate for the probability of satisfying the corresponding unbounded until property. In both phases, it is sufficient to verify bounded until properties which can be effectively done using existing statistical techniques. We prove the correctness of our technique and present its prototype implementations. We empirically show the practical applicability of our method by considering different case studies including a simple infinite-state model, and large finite-state models such as IPv4 zeroconf protocol and dining philosopher protocol modeled as Discrete Time Markov chains.

MTL-Model Checking of One-Clock Parametric Timed Automata is Undecidable

Directory of Open Access Journals (Sweden)

Karin Quaas

2014-03-01

Full Text Available Parametric timed automata extend timed automata (Alur and Dill, 1991 in that they allow the specification of parametric bounds on the clock values. Since their introduction in 1993 by Alur, Henzinger, and Vardi, it is known that the emptiness problem for parametric timed automata with one clock is decidable, whereas it is undecidable if the automaton uses three or more parametric clocks. The problem is open for parametric timed automata with two parametric clocks. Metric temporal logic, MTL for short, is a widely used specification language for real-time systems. MTL-model checking of timed automata is decidable, no matter how many clocks are used in the timed automaton. In this paper, we prove that MTL-model checking for parametric timed automata is undecidable, even if the automaton uses only one clock and one parameter and is deterministic.

An Efficient Explicit-time Description Method for Timed Model Checking

Directory of Open Access Journals (Sweden)

Hao Wang

2009-12-01

Full Text Available 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 pre-emptive scheduling. However, the Tick process in the above three methods increments the time by one unit in each tick; the state spaces therefore grow relatively fast as the time parameters increase, a problem when the system's time period is relatively long. In this paper, we propose a more efficient method which enables the Tick process to leap multiple time units in one tick. Preliminary experimental results in a high performance computing environment show that this new method significantly reduces the state space and improves both the time and memory efficiency.

Parameter discovery in stochastic biological models using simulated annealing and statistical model checking.

Science.gov (United States)

Hussain, Faraz; Jha, Sumit K; Jha, Susmit; Langmead, Christopher J

2014-01-01

Stochastic models are increasingly used to study the behaviour of biochemical systems. While the structure of such models is often readily available from first principles, unknown quantitative features of the model are incorporated into the model as parameters. Algorithmic discovery of parameter values from experimentally observed facts remains a challenge for the computational systems biology community. We present a new parameter discovery algorithm that uses simulated annealing, sequential hypothesis testing, and statistical model checking to learn the parameters in a stochastic model. We apply our technique to a model of glucose and insulin metabolism used for in-silico validation of artificial pancreata and demonstrate its effectiveness by developing parallel CUDA-based implementation for parameter synthesis in this model.

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

that require novel methods and applications. In this context, an important issue is the verification of certain quantitative properties of the system. In this paper, we consider a specific Chinese Smart Grid implementation as a case study and address the verification problem for performance and energy......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....

Possible check of the QCD parton model in semiinclusive μ- -production of tau/psi-meson

International Nuclear Information System (INIS)

Bagdasaryan, I.A.; Grigoryan, S.G.; Yesaibegyan, S.V.

1982-01-01

The process of tau/psi meson production in the semi-inclusive μN → μ+tau/psi+X interaction is discussed. It is shown that the measurement of azimuthal asymmetry in semi-inclusive production of tau/psi can serve as a good test for the check of the QCD parton model. An additional method of the check of distribution gluon functions in photon-gluon fusion model is suggested

Introduction of Virtualization Technology to Multi-Process Model Checking

Science.gov (United States)

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.

Race, Ethnicity, Psychosocial Factors, and Telomere Length in a Multicenter Setting.

Science.gov (United States)

Lynch, Shannon M; Peek, M K; Mitra, Nandita; Ravichandran, Krithika; Branas, Charles; Spangler, Elaine; Zhou, Wenting; Paskett, Electra D; Gehlert, Sarah; DeGraffinreid, Cecilia; Rebbeck, Timothy R; Riethman, Harold

2016-01-01

Leukocyte telomere length(LTL) has been associated with age, self-reported race/ethnicity, gender, education, and psychosocial factors, including perceived stress, and depression. However, inconsistencies in associations of LTL with disease and other phenotypes exist across studies. Population characteristics, including race/ethnicity, laboratory methods, and statistical approaches in LTL have not been comprehensively studied and could explain inconsistent LTL associations. LTL was measured using Southern Blot in 1510 participants from a multi-ethnic, multi-center study combining data from 3 centers with different population characteristics and laboratory processing methods. Main associations between LTL and psychosocial factors and LTL and race/ethnicity were evaluated and then compared across generalized estimating equations(GEE) and linear regression models. Statistical models were adjusted for factors typically associated with LTL(age, gender, cancer status) and also accounted for factors related to center differences, including laboratory methods(i.e., DNA extraction). Associations between LTL and psychosocial factors were also evaluated within race/ethnicity subgroups (Non-hispanic Whites, African Americans, and Hispanics). Beyond adjustment for age, gender, and cancer status, additional adjustments for DNA extraction and clustering by center were needed given their effects on LTL measurements. In adjusted GEE models, longer LTL was associated with African American race (Beta(β)(standard error(SE)) = 0.09(0.04), p-value = 0.04) and Hispanic ethnicity (β(SE) = 0.06(0.01), p-value = 0.02) compared to Non-Hispanic Whites. Longer LTL was also associated with less than a high school education compared to having greater than a high school education (β(SE) = 0.06(0.02), p-value = 0.04). LTL was inversely related to perceived stress (β(SE) = -0.02(0.003), pethnic circumstances and could impact future health disparity studies.

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 this paper we show how to do symbolic model checking using Boolean Expression Diagrams (BEDs), a non-canonical representation for Boolean formulas, instead of Binary Decision Diagrams (BDDs), the traditionally used canonical representation. The method is based on standard fixed point algorithm...

Logical Specification and Analysis of Fault Tolerant Systems through Partial Model Checking

NARCIS (Netherlands)

Gnesi, S.; Etalle, Sandro; Mukhopadhyay, S.; Lenzini, Gabriele; Lenzini, G.; Martinelli, F.; Roychoudhury, A.

2003-01-01

This paper presents a framework for a logical characterisation of fault tolerance and its formal analysis based on partial model checking techniques. The framework requires a fault tolerant system to be modelled using a formal calculus, here the CCS process algebra. To this aim we propose a uniform

Temporal Precedence Checking for Switched Models and its Application to a Parallel Landing Protocol

Science.gov (United States)

Duggirala, Parasara Sridhar; Wang, Le; Mitra, Sayan; Viswanathan, Mahesh; Munoz, Cesar A.

2014-01-01

This paper presents an algorithm for checking temporal precedence properties of nonlinear switched systems. This class of properties subsume bounded safety and capture requirements about visiting a sequence of predicates within given time intervals. The algorithm handles nonlinear predicates that arise from dynamics-based predictions used in alerting protocols for state-of-the-art transportation systems. It is sound and complete for nonlinear switch systems that robustly satisfy the given property. The algorithm is implemented in the Compare Execute Check Engine (C2E2) using validated simulations. As a case study, a simplified model of an alerting system for closely spaced parallel runways is considered. The proposed approach is applied to this model to check safety properties of the alerting logic for different operating conditions such as initial velocities, bank angles, aircraft longitudinal separation, and runway separation.

Research on vehicles and cargos matching model based on virtual logistics platform

Science.gov (United States)

Zhuang, Yufeng; Lu, Jiang; Su, Zhiyuan

2018-04-01

Highway less than truckload (LTL) transportation vehicles and cargos matching problem is a joint optimization problem of typical vehicle routing and loading, which is also a hot issue of operational research. This article based on the demand of virtual logistics platform, for the problem of the highway LTL transportation, the matching model of the idle vehicle and the transportation order is set up and the corresponding genetic algorithm is designed. Then the algorithm is implemented by Java. The simulation results show that the solution is satisfactory.

Model checking of safety-critical software in the nuclear engineering domain

International Nuclear Information System (INIS)

Lahtinen, J.; Valkonen, J.; Björkman, K.; Frits, J.; Niemelä, I.; Heljanko, K.

2012-01-01

Instrumentation and control (I and C) systems play a vital role in the operation of safety-critical processes. Digital programmable logic controllers (PLC) enable sophisticated control tasks which sets high requirements for system validation and verification methods. Testing and simulation have an important role in the overall verification of a system but are not suitable for comprehensive evaluation because only a limited number of system behaviors can be analyzed due to time limitations. Testing is also performed too late in the development lifecycle and thus the correction of design errors is expensive. This paper discusses the role of formal methods in software development in the area of nuclear engineering. It puts forward model checking, a computer-aided formal method for verifying the correctness of a system design model, as a promising approach to system verification. The main contribution of the paper is the development of systematic methodology for modeling safety critical systems in the nuclear domain. Two case studies are reviewed, in which we have found errors that were previously not detected. We also discuss the actions that should be taken in order to increase confidence in the model checking process.

PVeStA: A Parallel Statistical Model Checking and Quantitative Analysis Tool

KAUST Repository

AlTurki, Musab; Meseguer, José

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

Specification and Generation of Environment for Model Checking of Software Components

Czech Academy of Sciences Publication Activity Database

Pařízek, P.; Plášil, František

2007-01-01

Roč. 176, - (2007), s. 143-154 ISSN 1571-0661 R&D Projects: GA AV ČR 1ET400300504 Institutional research plan: CEZ:AV0Z10300504 Keywords : software components * behavior protocols * model checking * automated generation of environment Subject RIV: JC - Computer Hardware ; Software

UPPAAL-SMC: Statistical Model Checking for Priced Timed Automata

DEFF Research Database (Denmark)

Bulychev, Petr; David, Alexandre; Larsen, Kim Guldstrand

2012-01-01

on a series of extensions of the statistical model checking approach generalized to handle real-time systems and estimate undecidable problems. U PPAAL - SMC comes together with a friendly user interface that allows a user to specify complex problems in an efficient manner as well as to get feedback...... in the form of probability distributions and compare probabilities to analyze performance aspects of systems. The focus of the survey is on the evolution of the tool – including modeling and specification formalisms as well as techniques applied – together with applications of the tool to case studies....

Conformity checking of LPG Transportation Trucks by Modelling and Simulation

Directory of Open Access Journals (Sweden)

Gallab Maryam

2017-01-01

Full Text Available LPG Loading /unloading site is considered as a dangerous environment of significant risk, especially during LPG transfer operations. These risks may cause catastrophic dangers such as BLEVE (Boiling Liquid Expanding Vapour Explosion, UVCE (Unconfined Vapour Cloud Explosion, etc. The site consists of a tank (RST containing LPG and threetransfer posts. Two posts allow loading of small carrier tankers 6 tons. The other one transfer post transfer LPG contained injumbo tankers 20 tons inside the tank. The industrial site at risks chooses to demonstrate the need for a modelling-simulation approach. The aim is to check first compliance and authorization of the truck when it enters the site for loading /unloading, to verify the authorization to make the transfer, and then, to identify the driver and his training to ensure that the transfer operations are going to take place without incident. Sometimes, it may happen that Consignment Operator (CO is busy orabsent and thus the driver operates alone without being authorized, in this case the site risks a loss of control due to a lack of resources. The modelling-simulation will be done using multi-agent systems that will present the drivers, trucks, PO and loading unloading posts as agents in order to have a model facilitating this checking.

Dynamic modelling of check valves in shipping terminals; Modelagem dinamica de valvulas de retencao em terminais maritimos

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)

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...

Formal verification of dynamic hybrid systems: a NuSMV-based model checking approach

Directory of Open Access Journals (Sweden)

Xu Zhi

2018-01-01

Full Text Available Software security is an important and challenging research topic in developing dynamic hybrid embedded software systems. Ensuring the correct behavior of these systems is particularly difficult due to the interactions between the continuous subsystem and the discrete subsystem. Currently available security analysis methods for system risks have been limited, as they rely on manual inspections of the individual subsystems under simplifying assumptions. To improve this situation, a new approach is proposed that is based on the symbolic model checking tool NuSMV. A dual PID system is used as an example system, for which the logical part and the computational part of the system are modeled in a unified manner. Constraints are constructed on the controlled object, and a counter-example path is ultimately generated, indicating that the hybrid system can be analyzed by the model checking tool.

Undecidability of model-checking branching-time properties of stateless probabilistic pushdown process

OpenAIRE

Lin, T.

2014-01-01

In this paper, we settle a problem in probabilistic verification of infinite--state process (specifically, {\\it probabilistic pushdown process}). We show that model checking {\\it stateless probabilistic pushdown process} (pBPA) against {\\it probabilistic computational tree logic} (PCTL) is undecidable.

Race, Ethnicity, Psychosocial Factors, and Telomere Length in a Multicenter Setting.

Directory of Open Access Journals (Sweden)

Shannon M Lynch

Full Text Available Leukocyte telomere length(LTL has been associated with age, self-reported race/ethnicity, gender, education, and psychosocial factors, including perceived stress, and depression. However, inconsistencies in associations of LTL with disease and other phenotypes exist across studies. Population characteristics, including race/ethnicity, laboratory methods, and statistical approaches in LTL have not been comprehensively studied and could explain inconsistent LTL associations.LTL was measured using Southern Blot in 1510 participants from a multi-ethnic, multi-center study combining data from 3 centers with different population characteristics and laboratory processing methods. Main associations between LTL and psychosocial factors and LTL and race/ethnicity were evaluated and then compared across generalized estimating equations(GEE and linear regression models. Statistical models were adjusted for factors typically associated with LTL(age, gender, cancer status and also accounted for factors related to center differences, including laboratory methods(i.e., DNA extraction. Associations between LTL and psychosocial factors were also evaluated within race/ethnicity subgroups (Non-hispanic Whites, African Americans, and Hispanics.Beyond adjustment for age, gender, and cancer status, additional adjustments for DNA extraction and clustering by center were needed given their effects on LTL measurements. In adjusted GEE models, longer LTL was associated with African American race (Beta(β(standard error(SE = 0.09(0.04, p-value = 0.04 and Hispanic ethnicity (β(SE = 0.06(0.01, p-value = 0.02 compared to Non-Hispanic Whites. Longer LTL was also associated with less than a high school education compared to having greater than a high school education (β(SE = 0.06(0.02, p-value = 0.04. LTL was inversely related to perceived stress (β(SE = -0.02(0.003, p<0.001. In subgroup analyses, there was a negative association with LTL in African Americans with a high

Automated parameter estimation for biological models using Bayesian statistical model checking.

Science.gov (United States)

Hussain, Faraz; Langmead, Christopher J; Mi, Qi; Dutta-Moscato, Joyeeta; Vodovotz, Yoram; Jha, Sumit K

2015-01-01

Probabilistic models have gained widespread acceptance in the systems biology community as a useful way to represent complex biological systems. Such models are developed using existing knowledge of the structure and dynamics of the system, experimental observations, and inferences drawn from statistical analysis of empirical data. A key bottleneck in building such models is that some system variables cannot be measured experimentally. These variables are incorporated into the model as numerical parameters. Determining values of these parameters that justify existing experiments and provide reliable predictions when model simulations are performed is a key research problem. Using an agent-based model of the dynamics of acute inflammation, we demonstrate a novel parameter estimation algorithm by discovering the amount and schedule of doses of bacterial lipopolysaccharide that guarantee a set of observed clinical outcomes with high probability. We synthesized values of twenty-eight unknown parameters such that the parameterized model instantiated with these parameter values satisfies four specifications describing the dynamic behavior of the model. We have developed a new algorithmic technique for discovering parameters in complex stochastic models of biological systems given behavioral specifications written in a formal mathematical logic. Our algorithm uses Bayesian model checking, sequential hypothesis testing, and stochastic optimization to automatically synthesize parameters of probabilistic biological models.

Model-Checking of Linear-Time Properties in Multi-Valued Systems

OpenAIRE

Li, Yongming; Droste, Manfred; Lei, Lihui

2012-01-01

In this paper, we study model-checking of linear-time properties in multi-valued systems. Safety property, invariant property, liveness property, persistence and dual-persistence properties in multi-valued logic systems are introduced. Some algorithms related to the above multi-valued linear-time properties are discussed. The verification of multi-valued regular safety properties and multi-valued $\\omega$-regular properties using lattice-valued automata are thoroughly studied. Since the law o...

Patterns for a log-based strengthening of declarative compliance models

NARCIS (Netherlands)

Schunselaar, Dennis M.M.; Maggi, Fabrizio M.; Sidorova, Natalia

2012-01-01

LTL-based declarative process models are very effective when modelling loosely structured processes or working in environments with a lot of variability. A process model is represented by a set of constraints that must be satisfied during the process execution. An important application of such

Simple nonparametric checks for model data fit in CAT

NARCIS (Netherlands)

Meijer, R.R.

2005-01-01

In this paper, the usefulness of several nonparametric checks is discussed in a computerized adaptive testing (CAT) context. Although there is no tradition of nonparametric scalability in CAT, it can be argued that scalability checks can be useful to investigate, for example, the quality of item

Algebraic model checking for Boolean gene regulatory networks.

Science.gov (United States)

Tran, Quoc-Nam

2011-01-01

We present a computational method in which modular and Groebner bases (GB) computation in Boolean rings are used for solving problems in Boolean gene regulatory networks (BN). In contrast to other known algebraic approaches, the degree of intermediate polynomials during the calculation of Groebner bases using our method will never grow resulting in a significant improvement in running time and memory space consumption. We also show how calculation in temporal logic for model checking can be done by means of our direct and efficient Groebner basis computation in Boolean rings. We present our experimental results in finding attractors and control strategies of Boolean networks to illustrate our theoretical arguments. The results are promising. Our algebraic approach is more efficient than the state-of-the-art model checker NuSMV on BNs. More importantly, our approach finds all solutions for the BN problems.

Smoking habits and leukocyte telomere length dynamics among older adults: Results from the ESTHER cohort.

Science.gov (United States)

Müezzinler, Aysel; Mons, Ute; Dieffenbach, Aida Karina; Butterbach, Katja; Saum, Kai-Uwe; Schick, Matthias; Stammer, Hermann; Boukamp, Petra; Holleczek, Bernd; Stegmaier, Christa; Brenner, Hermann

2015-10-01

Leukocyte telomere length (LTL) shortens with age and short LTL has been associated with increased mortality and increased risk for some age-related outcomes. This study aims to analyse the associations of smoking habits with LTL and rate of LTL change per year in older adults. LTL was measured by quantitative PCR at baseline in 3600 older adults, who were enrolled in a population-based cohort study in Germany. For longitudinal analyses, measurements were repeated in blood samples obtained at 8-year follow-up from 1000 participants. Terminal Restriction Fragment analysis was additionally performed in a sub-sample to obtain absolute LTL in base pairs. Multivariate linear regression models were used to estimate associations of smoking habits with baseline LTL and changes in LTL over time. LTL was inversely associated with age (r=-0.090, pSmoking was inversely associated with LTL. On average, current smokers had 73 base pairs (BP) shorter LTL compared to never smokers. Smoking intensity and pack-years of smoking were also inversely associated with LTL, and a positive association was observed with years since smoking cessation. Slower LTL attrition rates were observed in ever smokers over 8years of follow-up. Our cross-sectional analysis supports suggestions that smoking might contribute to shortening of LTL but this relationship could not be shown longitudinally. The overall rather small effect sizes observed for smoking-related variables suggest that LTL reflects smoking-related health hazards only to a very limited extent. Copyright © 2015 Elsevier Inc. All rights reserved.

Analyzing Phylogenetic Trees with Timed and Probabilistic Model Checking: The Lactose Persistence Case Study.

Science.gov (United States)

Requeno, José Ignacio; Colom, José Manuel

2014-12-01

Model checking is a generic verification technique that allows the phylogeneticist to focus on models and specifications instead of on implementation issues. Phylogenetic trees are considered as transition systems over which we interrogate phylogenetic questions written as formulas of temporal logic. Nonetheless, standard logics become insufficient for certain practices of phylogenetic analysis since they do not allow the inclusion of explicit time and probabilities. The aim of this paper is to extend the application of model checking techniques beyond qualitative phylogenetic properties and adapt the existing logical extensions and tools to the field of phylogeny. The introduction of time and probabilities in phylogenetic specifications is motivated by the study of a real example: the analysis of the ratio of lactose intolerance in some populations and the date of appearance of this phenotype.

Solving scheduling problems by untimed model checking. The clinical chemical analyser case study

NARCIS (Netherlands)

Margaria, T.; Wijs, Anton J.; Massink, M.; van de Pol, Jan Cornelis; Bortnik, Elena M.

2009-01-01

In this article, we show how scheduling problems can be modelled in untimed process algebra, by using special tick actions. A minimal-cost trace leading to a particular action, is one that minimises the number of tick steps. As a result, we can use any (timed or untimed) model checking tool to find

Analysis of DIRAC's behavior using model checking with process algebra

International Nuclear Information System (INIS)

Remenska, Daniela; Templon, Jeff; Willemse, Tim; Bal, Henri; Verstoep, Kees; Fokkink, Wan; Charpentier, Philippe; Lanciotti, Elisa; Roiser, Stefan; Ciba, Krzysztof; Diaz, Ricardo Graciani

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 conventional testing, it allows full control over the parallel processes execution, and supports exhaustive state-space exploration. We used the mCRL2 language and toolset to model the behavior of two related DIRAC subsystems: the workload and storage management system. Based on process algebra, mCRL2 allows defining custom data types as well as functions over these. This makes it suitable for modeling the data manipulations made by DIRAC's agents. By visualizing the state space and replaying scenarios with the toolkit's simulator, we have detected race-conditions and deadlocks in these systems, which, in several cases, were confirmed to occur in the reality. Several properties of interest were formulated and verified with the tool. Our future direction is automating the translation from DIRAC to a formal model.

Analysis of DIRAC's behavior using model checking with process algebra

Science.gov (United States)

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.

How useful are delta checks in the 21st century? A stochastic-dynamic model of specimen mix-up and detection

Directory of Open Access Journals (Sweden)

Katie Ovens

2012-01-01

Full Text Available Introduction: Delta checks use two specimen test results taken in succession in order to detect test result changes greater than expected physiological variation. One of the most common and serious errors detected by delta checks is specimen mix-up errors. The positive and negative predictive values of delta checks for detecting specimen mix-up errors, however, are largely unknown. Materials and Methods: We addressed this question by first constructing a stochastic dynamic model using repeat test values for five analytes from approximately 8000 inpatients in Calgary, Alberta, Canada. The analytes examined were sodium, potassium, chloride, bicarbonate, and creatinine. The model simulated specimen mix-up errors by randomly switching a set number of pairs of second test results. Sensitivities and specificities were then calculated for each analyte for six combinations of delta check equations and cut-off values from the published literature. Results: Delta check specificities obtained from this model ranged from 50% to 99%; however the sensitivities were generally below 20% with the exception of creatinine for which the best performing delta check had a sensitivity of 82.8%. Within a plausible incidence range of specimen mix-ups the positive predictive values of even the best performing delta check equation and analyte became negligible. Conclusion: This finding casts doubt on the ongoing clinical utility of delta checks in the setting of low rates of specimen mix-ups.

Check, check, double check: checking the autopilot causes distrust : Experimental studies on the effects of compulsive perseveration

NARCIS (Netherlands)

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

Model analysis of check dam impacts on long-term sediment and water budgets in southeast Arizona, USA

Science.gov (United States)

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.

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...... limits of the approach are illustrated by a family of examples....

Fault Tree Analysis with Temporal Gates and Model Checking Technique for Qualitative System Safety Analysis

International Nuclear Information System (INIS)

Koh, Kwang Yong; Seong, Poong Hyun

2010-01-01

Fault tree analysis (FTA) has suffered from several drawbacks such that it uses only static gates and hence can not capture dynamic behaviors of the complex system precisely, and it is in lack of rigorous semantics, and reasoning process which is to check whether basic events really cause top events is done manually and hence very labor-intensive and time-consuming for the complex systems while it has been one of the most widely used safety analysis technique in nuclear industry. Although several attempts have been made to overcome this problem, they can not still do absolute or actual time modeling because they adapt relative time concept and can capture only sequential behaviors of the system. 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

Non intrusive check valve diagnostics at Bruce A

International Nuclear Information System (INIS)

Marsch, S.P.

1997-01-01

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)

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)

Causal model of safety-checking action of the staff of nuclear power plants and the organization climate

International Nuclear Information System (INIS)

Fukui, Hirokazu; Yoshida, Michio; Yamaura, Kazuho

2000-01-01

For those who run an organization, it is critical to identify the causal relationship between the organization's characteristics and the safety-checking action of its staff, in order to effectively implement activities for promoting safety. In this research. a causal model of the safety-checking action was developed and factors affecting it were studied. A questionnaire survey, which includes safety awareness, attitude toward safety, safety culture and others, was conducted at three nuclear power plants and eight factors were extracted by means of factor analysis of the questionnaire items. The extracted eight interrelated factors were as follows: work norm, supervisory action, interest in training, recognition of importance, safety-checking action, the subject of safety, knowledge/skills, and the attitude of an organization. Among them, seven factors except the recognition of importance were defined as latent variables and a causal model of safety-checking action was constructed. By means of covariance structure analysis, it was found that the three factors: the attitude of an organization, supervisory action and the subject of safety, have a significant effect on the safety-checking action. Moreover, it was also studied that workplaces in which these three factors are highly regarded form social environment where safety-checking action is fully supported by the workplace as a whole, while workplaces in which these three factors are poorly regarded do not fully form social environment where safety-checking action is supported. Therefore, the workplaces form an organizational environment where safety-checking action tends to depend strongly upon the knowledge or skills of individuals. On top of these, it was noted that the attitude of an organization and supervisory action are important factors that serve as the first trigger affecting the formation of the organizational climate for safety. (author)

Causal model of safety-checking action of the staff of nuclear power plants and the organization climate

Energy Technology Data Exchange (ETDEWEB)

Fukui, Hirokazu [Institute of Nuclear Safety System Inc., Seika, Kyoto (Japan); Yoshida, Michio; Yamaura, Kazuho [Japan Institute for Group Dynamics, Fukuoka (Japan)

2000-09-01

For those who run an organization, it is critical to identify the causal relationship between the organization's characteristics and the safety-checking action of its staff, in order to effectively implement activities for promoting safety. In this research. a causal model of the safety-checking action was developed and factors affecting it were studied. A questionnaire survey, which includes safety awareness, attitude toward safety, safety culture and others, was conducted at three nuclear power plants and eight factors were extracted by means of factor analysis of the questionnaire items. The extracted eight interrelated factors were as follows: work norm, supervisory action, interest in training, recognition of importance, safety-checking action, the subject of safety, knowledge/skills, and the attitude of an organization. Among them, seven factors except the recognition of importance were defined as latent variables and a causal model of safety-checking action was constructed. By means of covariance structure analysis, it was found that the three factors: the attitude of an organization, supervisory action and the subject of safety, have a significant effect on the safety-checking action. Moreover, it was also studied that workplaces in which these three factors are highly regarded form social environment where safety-checking action is fully supported by the workplace as a whole, while workplaces in which these three factors are poorly regarded do not fully form social environment where safety-checking action is supported. Therefore, the workplaces form an organizational environment where safety-checking action tends to depend strongly upon the knowledge or skills of individuals. On top of these, it was noted that the attitude of an organization and supervisory action are important factors that serve as the first trigger affecting the formation of the organizational climate for safety. (author)

Analysis of DGNB-DK criteria for BIM-based Model Checking automatization

DEFF Research Database (Denmark)

Gade, Peter Nørkjær; 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 rule-based approach to model checking of UML state machines

Science.gov (United States)

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.

Serum Folate, Vitamin B-12, Vitamin A, γ-Tocopherol, α-Tocopherol, and Carotenoids Do Not Modify Associations between Cadmium Exposure and Leukocyte Telomere Length in the General US Adult Population.

Science.gov (United States)

Nomura, Sarah Jo; Robien, Kim; Zota, Ami R

2017-04-01

Background: Leukocyte telomere length (LTL) is a biomarker of the aging process and is associated with the risk of chronic disease. Higher exposure to cadmium may be associated with shorter LTL, and adequate nutrient concentrations may be associated with longer LTL; however, the potential interaction between metals and nutrients on LTL has yet to be examined. Objectives: The objective of this study was to evaluate whether serum concentrations of vitamins and carotenoids were associated with LTL, and whether they modified the association between blood cadmium and LTL in the US NHANES (1999-2002). Methods: We evaluated cross-sectional associations between LTL and serum concentrations of vitamin A, γ-tocopherol, α-tocopherol, folate, and vitamin B-12 (1999-2002; n = 7458) and α-carotene, β-carotene, β-cryptoxanthin, lutein + zeaxanthin, and lycopene (2001-2002; n = 4018) in a nationally representative sample of US adults (≥20 y of age) with the use of multivariable linear regression. We further investigated whether vitamin and carotenoid concentrations modified associations between blood cadmium and LTL with models stratified by serum nutrient concentrations and the inclusion of an interaction term. Results: Blood cadmium was inversely associated with LTL (percentage of LTL difference per 1 μg/L = -3.74; 95% CI: -5.35, -2.10). Serum vitamin A was positively associated (percentage of LTL difference per 1 μg/L = 4.01; 95% CI: 0.26, 7.90) and γ-tocopherol was inversely associated (percentage of LTL difference per 1 μg/dL = -2.49; 95% CI: -4.21, -0.73) with LTL. Serum folate ( P -trend = 0.06) and α-tocopherol ( P -trend = 0.10) were marginally positively associated with LTL, whereas vitamin B-12 ( P -trend = 0.78) was not associated with LTL. Serum carotenoids were generally positively associated with LTL. Serum vitamin and carotenoid concentrations did not modify blood cadmium and LTL associations ( P -interaction > 0.10). Conclusions: Results from this

Serum Folate, Vitamin B-12, Vitamin A, γ-Tocopherol, α-Tocopherol, and Carotenoids Do Not Modify Associations between Cadmium Exposure and Leukocyte Telomere Length in the General US Adult Population123

Science.gov (United States)

2017-01-01

Background: Leukocyte telomere length (LTL) is a biomarker of the aging process and is associated with the risk of chronic disease. Higher exposure to cadmium may be associated with shorter LTL, and adequate nutrient concentrations may be associated with longer LTL; however, the potential interaction between metals and nutrients on LTL has yet to be examined. Objectives: The objective of this study was to evaluate whether serum concentrations of vitamins and carotenoids were associated with LTL, and whether they modified the association between blood cadmium and LTL in the US NHANES (1999–2002). Methods: We evaluated cross-sectional associations between LTL and serum concentrations of vitamin A, γ-tocopherol, α-tocopherol, folate, and vitamin B-12 (1999–2002; n = 7458) and α-carotene, β-carotene, β-cryptoxanthin, lutein + zeaxanthin, and lycopene (2001–2002; n = 4018) in a nationally representative sample of US adults (≥20 y of age) with the use of multivariable linear regression. We further investigated whether vitamin and carotenoid concentrations modified associations between blood cadmium and LTL with models stratified by serum nutrient concentrations and the inclusion of an interaction term. Results: Blood cadmium was inversely associated with LTL (percentage of LTL difference per 1 μg/L = −3.74; 95% CI: −5.35, −2.10). Serum vitamin A was positively associated (percentage of LTL difference per 1 μg/L = 4.01; 95% CI: 0.26, 7.90) and γ-tocopherol was inversely associated (percentage of LTL difference per 1 μg/dL = −2.49; 95% CI: −4.21, −0.73) with LTL. Serum folate (P-trend = 0.06) and α-tocopherol (P-trend = 0.10) were marginally positively associated with LTL, whereas vitamin B-12 (P-trend = 0.78) was not associated with LTL. Serum carotenoids were generally positively associated with LTL. Serum vitamin and carotenoid concentrations did not modify blood cadmium and LTL associations (P-interaction > 0.10). Conclusions: Results from

Assessment of check-dam groundwater recharge with water-balance calculations

Science.gov (United States)

Djuma, Hakan; Bruggeman, Adriana; Camera, Corrado; Eliades, Marinos

2017-04-01

Studies on the enhancement of groundwater recharge by check-dams in arid and semi-arid environments mainly focus on deriving water infiltration rates from the check-dam ponding areas. This is usually achieved by applying simple water balance models, more advanced models (e.g., two dimensional groundwater models) and field tests (e.g., infiltrometer test or soil pit tests). Recharge behind the check-dam can be affected by the built-up of sediment as a result of erosion in the upstream watershed area. This natural process can increase the uncertainty in the estimates of the recharged water volume, especially for water balance calculations. Few water balance field studies of individual check-dams have been presented in the literature and none of them presented associated uncertainties of their estimates. The objectives of this study are i) to assess the effect of a check-dam on groundwater recharge from an ephemeral river; and ii) to assess annual sedimentation at the check-dam during a 4-year period. The study was conducted on a check-dam in the semi-arid island of Cyprus. Field campaigns were carried out to measure water flow, water depth and check-dam topography in order to establish check-dam water height, volume, evaporation, outflow and recharge relations. Topographic surveys were repeated at the end of consecutive hydrological years to estimate the sediment built up in the reservoir area of the check dam. Also, sediment samples were collected from the check-dam reservoir area for bulk-density analyses. To quantify the groundwater recharge, a water balance model was applied at two locations: at the check-dam and corresponding reservoir area, and at a 4-km stretch of the river bed without check-dam. Results showed that a check-dam with a storage capacity of 25,000 m3 was able to recharge to the aquifer, in four years, a total of 12 million m3 out of the 42 million m3 of measured (or modelled) streamflow. Recharge from the analyzed 4-km long river section without

Classification and checking model of pedestrian crossing

Directory of Open Access Journals (Sweden)

Luis Delgado Méndez

2012-11-01

After realizing this investigation it can be confirmed that the functionality of a pedestrian crossing depends on almost a hundred parameters which must be checked or measured, in turn proving that this design and construction process is indeed complex.

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.

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...... that require novel methods and applications. One of the important issues in this context is the verification of certain quantitative properties of the system. In this paper, we consider a specific Chinese smart grid implementation as a case study and address the verification problem for performance and energy...... consumption.We employ stochastic model checking approach and present our modelling and analysis study using PRISM model checker....

Transformation of UML Behavioral Diagrams to Support Software Model Checking

Directory of Open Access Journals (Sweden)

Luciana Brasil Rebelo dos Santos

2014-04-01

Full Text Available Unified Modeling Language (UML is currently accepted as the standard for modeling (object-oriented software, and its use is increasing in the aerospace industry. Verification and Validation of complex software developed according to UML is not trivial due to complexity of the software itself, and the several different UML models/diagrams that can be used to model behavior and structure of the software. This paper presents an approach to transform up to three different UML behavioral diagrams (sequence, behavioral state machines, and activity into a single Transition System to support Model Checking of software developed in accordance with UML. In our approach, properties are formalized based on use case descriptions. The transformation is done for the NuSMV model checker, but we see the possibility in using other model checkers, such as SPIN. The main contribution of our work is the transformation of a non-formal language (UML to a formal language (language of the NuSMV model checker towards a greater adoption in practice of formal methods in software development.

The Effects of Check-In, Check-Up, Check-Out for Students with Moderate Intellectual Disability during On- and Off-Site Vocational Training

Science.gov (United States)

Boden, Lauren J.; Jolivette, Kristine; Alberto, Paul A.

2018-01-01

Check-in/check-out is a secondary-tier intervention within the positive behavior interventions and supports framework. Check-in/check-out pairs the use of an adult mentor with a daily progress report to help students meet individualized behavioral goals. This study adds to the research base by examining the effects of check-in, check-up, check-out…

Regular health checks

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....

40 CFR 86.327-79 - Quench checks; NOX analyzer.

Science.gov (United States)

2010-07-01

... any flow rate into the reaction chamber. This includes, but is not limited to, sample capillary, ozone... Quench checks; NOX analyzer. (a) Perform the reaction chamber quench check for each model of high vacuum reaction chamber analyzer prior to initial use. (b) Perform the reaction chamber quench check for each new...

Checking Java Programs

CERN Document Server

Darwin, Ian

2007-01-01

This Short Cut tells you about tools that will improve the quality of your Java code, using checking above and beyond what the standard tools do, including: Using javac options, JUnit and assertions Making your IDE work harder Checking your source code with PMD Checking your compiled code (.class files) with FindBugs Checking your program's run-time behavior with Java PathFinder

Sediment depositions upstream of open check dams: new elements from small scale models

Science.gov (United States)

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).

Chiefly Symmetric: Results on the Scalability of Probabilistic Model Checking for Operating-System Code

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.

Checking behavioral conformance of artifacts

NARCIS (Netherlands)

Fahland, D.; Leoni, de M.; Dongen, van B.F.; Aalst, van der W.M.P.

2011-01-01

The usefulness of process models (e.g., for analysis, improvement, or execution) strongly depends on their ability to describe reality. Conformance checking is a technique to validate how good a given process model describes recorded executions of the actual process. Recently, artifacts have been

Re-engineering pre-employment check-up systems: a model for improving health services.

Science.gov (United States)

Rateb, Said Abdel Hakim; El Nouman, Azza Abdel Razek; Rateb, Moshira Abdel Hakim; Asar, Mohamed Naguib; El Amin, Ayman Mohammed; Gad, Saad abdel Aziz; Mohamed, Mohamed Salah Eldin

2011-01-01

The purpose of this paper is to develop a model for improving health services provided by the pre-employment medical fitness check-up system affiliated to Egypt's Health Insurance Organization (HIO). Operations research, notably system re-engineering, is used in six randomly selected centers and findings before and after re-engineering are compared. The re-engineering model follows a systems approach, focusing on three areas: structure, process and outcome. The model is based on six main components: electronic booking, standardized check-up processes, protected medical documents, advanced archiving through an electronic content management (ECM) system, infrastructure development, and capacity building. The model originates mainly from customer needs and expectations. The centers' monthly customer flow increased significantly after re-engineering. The mean time spent per customer cycle improved after re-engineering--18.3 +/- 5.5 minutes as compared to 48.8 +/- 14.5 minutes before. Appointment delay was also significantly decreased from an average 18 to 6.2 days. Both beneficiaries and service providers were significantly more satisfied with the services after re-engineering. The model proves that re-engineering program costs are exceeded by increased revenue. Re-engineering in this study involved multiple structure and process elements. The literature review did not reveal similar re-engineering healthcare packages. Therefore, each element was compared separately. This model is highly recommended for improving service effectiveness and efficiency. This research is the first in Egypt to apply the re-engineering approach to public health systems. Developing user-friendly models for service improvement is an added value.

From Collective Adaptive Systems to Human Centric Computation and Back: Spatial Model Checking for Medical Imaging

Directory of Open Access Journals (Sweden)

Gina Belmonte

2016-07-01

Full Text Available Recent research on formal verification for Collective Adaptive Systems (CAS pushed advancements in spatial and spatio-temporal model checking, and as a side result provided novel image analysis methodologies, rooted in logical methods for topological spaces. Medical Imaging (MI is a field where such technologies show potential for ground-breaking innovation. In this position paper, we present a preliminary investigation centred on applications of spatial model checking to MI. The focus is shifted from pure logics to a mixture of logical, statistical and algorithmic approaches, driven by the logical nature intrinsic to the specification of the properties of interest in the field. As a result, novel operators are introduced, that could as well be brought back to the setting of CAS.

14 CFR 121.411 - Qualifications: Check airmen (airplane) and check airmen (simulator).

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Qualifications: Check airmen (airplane) and... § 121.411 Qualifications: Check airmen (airplane) and check airmen (simulator). (a) For the purposes of this section and § 121.413: (1) A check airman (airplane) is a person who is qualified, and permitted...

Next-generation nozzle check valve significantly reduces operating costs

Energy Technology Data Exchange (ETDEWEB)

Roorda, O. [SMX International, Toronto, ON (Canada)

2009-01-15

Check valves perform an important function in preventing reverse flow and protecting plant and mechanical equipment. However, the variety of different types of valves and extreme differences in performance even within one type can change maintenance requirements and life cycle costs, amounting to millions of dollars over the typical 15-year design life of piping components. A next-generation non-slam nozzle check valve which prevents return flow has greatly reduced operating costs by protecting the mechanical equipment in a piping system. This article described the check valve varieties such as the swing check valve, a dual-plate check valve, and nozzle check valves. Advancements in optimized design of a non-slam nozzle check valve were also discussed, with particular reference to computer flow modelling such as computational fluid dynamics; computer stress modelling such as finite element analysis; and flow testing (using rapid prototype development and flow loop testing), both to improve dynamic performance and reduce hydraulic losses. The benefits of maximized dynamic performance and minimized pressure loss from the new designed valve were also outlined. It was concluded that this latest non-slam nozzle check valve design has potential applications in natural gas, liquefied natural gas, and oil pipelines, including subsea applications, as well as refineries, and petrochemical plants among others, and is suitable for horizontal and vertical installation. The result of this next-generation nozzle check valve design is not only superior performance, and effective protection of mechanical equipment but also minimized life cycle costs. 1 fig.

Simulation-based model checking approach to cell fate specification during Caenorhabditis elegans vulval development by hybrid functional Petri net with extension

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

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.

Location Contexts of User Check-Ins to Model Urban Geo Life-Style Patterns

Science.gov (United States)

Hasan, Samiul; Ukkusuri, Satish V.

2015-01-01

Geo-location data from social media offers us information, in new ways, to understand people's attitudes and interests through their activity choices. In this paper, we explore the idea of inferring individual life-style patterns from activity-location choices revealed in social media. We present a model to understand life-style patterns using the contextual information (e. g. location categories) of user check-ins. Probabilistic topic models are developed to infer individual geo life-style patterns from two perspectives: i) to characterize the patterns of user interests to different types of places and ii) to characterize the patterns of user visits to different neighborhoods. The method is applied to a dataset of Foursquare check-ins of the users from New York City. The co-existence of several location contexts and the corresponding probabilities in a given pattern provide useful information about user interests and choices. It is found that geo life-style patterns have similar items—either nearby neighborhoods or similar location categories. The semantic and geographic proximity of the items in a pattern reflects the hidden regularity in user preferences and location choice behavior. PMID:25970430

Check valve

Science.gov (United States)

Upton, H.A.; Garcia, P.

1999-08-24

A check valve for use in a GDCS of a nuclear reactor and having a motor driven disk including a rotatable armature for rotating the check valve disk over its entire range of motion is described. In one embodiment, the check valve includes a valve body having a coolant flow channel extending therethrough. The coolant flow channel includes an inlet end and an outlet end. A valve body seat is located on an inner surface of the valve body. The check valve further includes a disk assembly, sometimes referred to as the motor driven disc, having a counterweight and a disk shaped valve. The disk valve includes a disk base having a seat for seating with the valve body seat. The disk assembly further includes a first hinge pin member which extends at least partially through the disk assembly and is engaged to the disk. The disk valve is rotatable relative to the first hinge pin member. The check valve also includes a motor having a stator frame with a stator bore therein. An armature is rotatably positioned within the stator bore and the armature is coupled to the disk valve to cause the disk valve to rotate about its full range of motion. 5 figs.

Check valve

International Nuclear Information System (INIS)

Upton, H.A.; Garcia, P.

1999-01-01

A check valve for use in a GDCS of a nuclear reactor and having a motor driven disk including a rotatable armature for rotating the check valve disk over its entire range of motion is described. In one embodiment, the check valve includes a valve body having a coolant flow channel extending therethrough. The coolant flow channel includes an inlet end and an outlet end. A valve body seat is located on an inner surface of the valve body. The check valve further includes a disk assembly, sometimes referred to as the motor driven disc, having a counterweight and a disk shaped valve. The disk valve includes a disk base having a seat for seating with the valve body seat. The disk assembly further includes a first hinge pin member which extends at least partially through the disk assembly and is engaged to the disk. The disk valve is rotatable relative to the first hinge pin member. The check valve also includes a motor having a stator frame with a stator bore therein. An armature is rotatably positioned within the stator bore and the armature is coupled to the disk valve to cause the disk valve to rotate about its full range of motion. 5 figs

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

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......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...... 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...

Transient analysis for a system with a tilted disc check valve

International Nuclear Information System (INIS)

Jeung, Jaesik; Lee, Kyukwang; Cho, Daegwan

2014-01-01

Check valves are used to prevent reverse flow conditions in a variety of systems in nuclear power plants. When a check valve is closed by a reverse flow, the transient load can jeopardize the structural integrity on the piping system and its supports. It may also damage intended function of the in-line components even though the severity of the load differs and depends strongly on types of the check valves. To incorporate the transient load in the piping system, it is very important to properly predict the system response to transients such as a check valve closure accompanied by pump trip and to evaluate the system transient. The one-dimensional transient simulation codes such as the RELAP5/MOD3.3 and TRACE were used. There has not been a single model that integrates the two codes to handle the behavior of a tilted disc check valve, which is designed to mitigate check valve slams by shorting the travel of the disc. In this paper a model is presented to predict the dynamic motion of a tilted disc check valve in the transient simulation using the RELAP5/MOD3.3 code and the model is incorporated in a system transient analysis using control variables of the code. In addition, transient analysis for Essential Service Water (ESW) system is performed using the proposed model and the associated load is evaluated for the system. (author)

Sports and Exercise at Different Ages and Leukocyte Telomere Length in Later Life--Data from the Berlin Aging Study II (BASE-II).

Science.gov (United States)

Saßenroth, Denise; Meyer, Antje; Salewsky, Bastian; Kroh, Martin; Norman, Kristina; Steinhagen-Thiessen, Elisabeth; Demuth, Ilja

2015-01-01

Physical activity and sports have repeatedly been reported to be associated with telomere length. We studied the association of different types of sports across different stages of life on relative leukocyte telomere length (rLTL) in advanced age.815 participants (397 men) from the Berlin Aging Study II aged over 61 years were included in the analysis. rLTL was measured by real time PCR and physical activity was determined retrospectively by questionnaire, assessing type and duration of sports in the past as well as currently. Five separate multiple linear regression models adjusted for various control variables were performed. 67.3% of participants exercised currently, whereas 19.4% performed sports only between the age of 20 and 30. rLTL was higher in subjects who stated to exercise currently (N = 456), and in subjects who engaged in endurance (N = 138) or intensive activity sports (N = 32). Current physical activity was positively associated with rLTL in the risk factor adjusted regression model (β = 0.26, p sports for a minimum of 10 years preceding the assessment had a significant effect on rLTL (β = 0.39, p = 0.011). The highest impact was seen for intensive activity sports (β = 0.79, p sports at all (β = -0.16, p = 0.21). Physical activity is clearly associated with longer rLTL. The effect is seen with longer periods of physical activity (at least 10 years), with intensive sports activities having the greatest impact on rLTL. Our data suggest that regular physical activity for at least 10 years is necessary to achieve a sustained effect on rLTL.

Logic Model Checking of Unintended Acceleration Claims in the 2005 Toyota Camry Electronic Throttle Control System

Science.gov (United States)

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

14 CFR 91.1089 - Qualifications: Check pilots (aircraft) and check pilots (simulator).

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Qualifications: Check pilots (aircraft) and check pilots (simulator). 91.1089 Section 91.1089 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... RULES Fractional Ownership Operations Program Management § 91.1089 Qualifications: Check pilots...

WE-E-BRB-10: DosCheck - an Electronic Chart Checking Tool for Dosimetrists.

Science.gov (United States)

Yang, D; Wu, Y; Yaddanapudi, S; Moore, K; Pierbuxg, B; Brame, S; Mutic, S

2012-06-01

In addition to treatment planning, dosimetrists have to prepare documentation and manually enter data in treatment management system (TMS) which did not transfer or setup automatically. The required documents and data are dependent on the disease site, treatment machine and clinical workflow. Errors and inconsistencies can cause redundant work, treatment delays and potentially treatment errors. To address these issues, an electronic checking software tool, DosCheck was clinically implemented to check the existence of necessary documentations and the integrity of manually-entered data. The purpose of this software is to reduce the frequency of human errors and to improve efficiency. DosCheck reads data and documents from 1) TMS, 2) Pinnacle TPS, and 3) DICOM plan files stored in a DICOM-RT PACS. It processes documents in Word and PDF format, treatment plan data in Pinnacle native format and DICOM format, and Mosaiq data in database records. The software cross-checks data accuracy and consistency by following rules that are pre-defined according to the clinical requirements and treatment sties. It interacts with dosimetrists and presents instantaneous results via graphical user interface. DosCheck has been implemented in C#. It performs a full check for a patient with 20 seconds. It has been clinically commissioned and is used daily by all dosimetrists at our institution. Retrospective analysis shows that DosCheck identifies 30% to 40% of previously reported dosimetrist human errors. Additional ∼30% errors are checked by other tools that could be integrated DosCheck in the near future. As an electronic data checking tool, DosCheck can obtain and process data and documents from multiple clinical computer systems in the radiation oncology department, and perform checks according to clinical rules. It is able to improve the accuracy and efficiency of clinical data and document process, and therefore to reduce any potential inconsistencies and errors. © 2012 American

Do leukocyte telomere length dynamics depend on baseline telomere length? An analysis that corrects for ‘regression to the mean’

International Nuclear Information System (INIS)

Verhulst, Simon; Aviv, Abraham; Benetos, Athanase; Berenson, Gerald S.; Kark, Jeremy D.

2013-01-01

Leukocyte telomere length (LTL) shortens with age. Longitudinal studies have reported accelerated LTL attrition when baseline LTL is longer. However, the dependency of LTL attrition on baseline LTL might stem from a statistical artifact known as regression to the mean (RTM). To our knowledge no published study of LTL dynamics (LTL and its attrition rate) has corrected for this phenomenon. We illustrate the RTM effect using replicate LTL measurements, and show, using simulated data, how the RTM effect increases with a rise in stochastic measurement variation (representing LTL measurement error), resulting in spurious increasingly elevated dependencies of attrition on baseline values. In addition, we re-analyzed longitudinal LTL data collected from four study populations to test the hypothesis that LTL attrition depends on baseline LTL. We observed that the rate of LTL attrition was proportional to baseline LTL, but correction for the RTM effect reduced the slope of the relationship by 57 % when measurement error was low (coefficient of variation ∼2 %). A modest but statistically significant effect remained however, indicating that high baseline LTL is associated with higher LTL attrition even when correcting for the RTM effect. Baseline LTL explained 1.3 % of the variation in LTL attrition, but this effect, which differed significantly between the study samples, appeared to be primarily attributable to the association in men (3.7 %)

Fluid Petri Nets and hybrid model-checking: a comparative case study

International Nuclear Information System (INIS)

Gribaudo, M.; Horvath, A.; Bobbio, A.; Tronci, E.; Ciancamerla, E.; Minichino, M.

2003-01-01

The modeling and analysis of hybrid systems is a recent and challenging research area which is actually dominated by two main lines: a functional analysis based on the description of the system in terms of discrete state (hybrid) automata (whose goal is to ascertain conformity and reachability properties), and a stochastic analysis (whose aim is to provide performance and dependability measures). This paper investigates a unifying view between formal methods and stochastic methods by proposing an analysis methodology of hybrid systems based on Fluid Petri Nets (FPNs). FPNs can be analyzed directly using appropriate tools. Our paper shows that the same FPN model can be fed to different functional analyzers for model checking. In order to extensively explore the capability of the technique, we have converted the original FPN into languages for discrete as well as hybrid as well as stochastic model checkers. In this way, a first comparison among the modeling power of well known tools can be carried out. Our approach is illustrated by means of a 'real world' hybrid system: the temperature control system of a co-generative plant

Spot-checks to measure general hygiene practice.

Science.gov (United States)

Sonego, Ina L; Mosler, Hans-Joachim

2016-01-01

A variety of hygiene behaviors are fundamental to the prevention of diarrhea. We used spot-checks in a survey of 761 households in Burundi to examine whether something we could call general hygiene practice is responsible for more specific hygiene behaviors, ranging from handwashing to sweeping the floor. Using structural equation modeling, we showed that clusters of hygiene behavior, such as primary caregivers' cleanliness and household cleanliness, explained the spot-check findings well. Within our model, general hygiene practice as overall concept explained the more specific clusters of hygiene behavior well. Furthermore, the higher general hygiene practice, the more likely children were to be categorized healthy (r = 0.46). General hygiene practice was correlated with commitment to hygiene (r = 0.52), indicating a strong association to psychosocial determinants. The results show that different hygiene behaviors co-occur regularly. Using spot-checks, the general hygiene practice of a household can be rated quickly and easily.

Model Checking A Self-Stabilizing Synchronization Protocol for Arbitrary Digraphs

Science.gov (United States)

Malekpour, Mahyar R.

2012-01-01

This report presents the mechanical verification of a self-stabilizing distributed clock synchronization protocol for arbitrary digraphs in the absence of faults. This protocol does not rely on assumptions about the initial state of the system, other than the presence of at least one node, and no central clock or a centrally generated signal, pulse, or message is used. The system under study is an arbitrary, non-partitioned digraph ranging from fully connected to 1-connected networks of nodes while allowing for differences in the network elements. Nodes are anonymous, i.e., they do not have unique identities. There is no theoretical limit on the maximum number of participating nodes. The only constraint on the behavior of the node is that the interactions with other nodes are restricted to defined links and interfaces. This protocol deterministically converges within a time bound that is a linear function of the self-stabilization period. A bounded model of the protocol is verified using the Symbolic Model Verifier (SMV) for a subset of digraphs. Modeling challenges of the protocol and the system are addressed. The model checking effort is focused on verifying correctness of the bounded model of the protocol as well as confirmation of claims of determinism and linear convergence with respect to the self-stabilization period.

The Effectiveness of Cooperative Learning Model of Pair Checks Type on Motivation and Mathematics Learning Outcomes of 8th Grade Junior High School Students

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Wahyu Budi Wicaksono

2017-08-01

Full Text Available The purpose of this research was to know the effectiveness of Pair Checks cooperative model towards students’ learning result and learning motivation of eight grade. Population of this research were students of eight grade Junior High School 2 Pati in the academic year 2016/1017. The research used cluster random sampling technique.Where the selected samples were students of class VIII H as experimental class and class VIII G as control class. The data collected by the method of documentation, test methods, and scale methods. The analyzed of data used completeness test and average different test. The results showed that: (1 students’ learning result who join Pair Checks cooperative model have classical study completeness; (2 students’ mathematics learning result who join Pair Checks cooperative model is better than students mathematics learning result who join ekspository learning; (3 students’ learning motivation who join Pair Checks cooperative model is better than students’ learning motivation who join ekspository learning.

Checking the validity of Busquet's ionization temperature with detailed collisional radiative models.

Science.gov (United States)

Klapisch, M.; Bar-Shalom, A.

1997-12-01

Busquet's RADIOM model for effective ionization temperature Tz is an appealing and simple way to introduce non LTE effects in hydrocodes. The authors report checking the validity of RADIOM in the optically thin case by comparison with two collisional radiative models, MICCRON (level-by-level) for C and Al and SCROLL (superconfiguration- by-superconfiguration) for Lu and Au. MICCRON is described in detail. The agreement between the average ion charge >ZBusquet is very good in most cases. There is however room for improvement when the departure from LTE is more pronounced for heavy atoms and for emissivity. Improvement appears possible because the concept of ionization temperature seems to hold in a broader range of parameters.

Toward improved design of check dam systems: A case study in the Loess Plateau, China

Science.gov (United States)

Pal, Debasish; Galelli, Stefano; Tang, Honglei; Ran, Qihua

2018-04-01

Check dams are one of the most common strategies for controlling sediment transport in erosion prone areas, along with soil and water conservation measures. However, existing mathematical models that simulate sediment production and delivery are often unable to simulate how the storage capacity of check dams varies with time. To explicitly account for this process-and to support the design of check dam systems-we developed a modelling framework consisting of two components, namely (1) the spatially distributed Soil Erosion and Sediment Delivery Model (WaTEM/SEDEM), and (2) a network-based model of check dam storage dynamics. The two models are run sequentially, with the second model receiving the initial sediment input to check dams from WaTEM/SEDEM. The framework is first applied to Shejiagou catchment, a 4.26 km2 area located in the Loess Plateau, China, where we study the effect of the existing check dam system on sediment dynamics. Results show that the deployment of check dams altered significantly the sediment delivery ratio of the catchment. Furthermore, the network-based model reveals a large variability in the life expectancy of check dams and abrupt changes in their filling rates. The application of the framework to six alternative check dam deployment scenarios is then used to illustrate its usefulness for planning purposes, and to derive some insights on the effect of key decision variables, such as the number, size, and site location of check dams. Simulation results suggest that better performance-in terms of life expectancy and sediment delivery ratio-could have been achieved with an alternative deployment strategy.

Model Checking Verification and Validation at JPL and the NASA Fairmont IV and V Facility

Science.gov (United States)

Schneider, Frank; Easterbrook, Steve; Callahan, Jack; Montgomery, Todd

1999-01-01

We show how a technology transfer effort was carried out. The successful use of model checking on a pilot JPL flight project demonstrates the usefulness and the efficacy of the approach. The pilot project was used to model a complex spacecraft controller. Software design and implementation validation were carried out successfully. To suggest future applications we also show how the implementation validation step can be automated. The effort was followed by the formal introduction of the modeling technique as a part of the JPL Quality Assurance process.

Bringing Automated Model Checking to PLC Program Development - A CERN Case Study

CERN Document Server

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, ...

Combining Static Model Checking with Dynamic Enforcement Using the Statecall Policy Language

Science.gov (United States)

Madhavapeddy, Anil

Internet protocols encapsulate a significant amount of state, making implementing the host software complex. In this paper, we define the Statecall Policy Language (SPL) which provides a usable middle ground between ad-hoc coding and formal reasoning. It enables programmers to embed automata in their code which can be statically model-checked using SPIN and dynamically enforced. The performance overheads are minimal, and the automata also provide higher-level debugging capabilities. We also describe some practical uses of SPL by describing the automata used in an SSH server written entirely in OCaml/SPL.

Error Checking for Chinese Query by Mining Web Log

Directory of Open Access Journals (Sweden)

Jianyong Duan

2015-01-01

Full Text Available For the search engine, error-input query is a common phenomenon. This paper uses web log as the training set for the query error checking. Through the n-gram language model that is trained by web log, the queries are analyzed and checked. Some features including query words and their number are introduced into the model. At the same time data smoothing algorithm is used to solve data sparseness problem. It will improve the overall accuracy of the n-gram model. The experimental results show that it is effective.

Leukocyte telomere dynamics in the elderly

DEFF Research Database (Denmark)

Steenstrup, Troels; Hjelmborg, Jacob V B; Mortensen, Laust H

2013-01-01

Limited data suggest that leukocytes of the elderly display ultra-short telomeres. It was reported that in some elderly persons leukocyte telomere length (LTL) shows age-dependent elongation. Using cross-sectional and longitudinal models, we characterized LTL dynamics in participants...

Plant experience with check valves in passive systems

Energy Technology Data Exchange (ETDEWEB)

Pahladsingh, R R [GKN Joint Nuclear Power Plant, Dodewaard (Netherlands)

1996-12-01

In the design of the advanced nuclear reactors there is a tendency to introduce more passive safety systems. The 25 year old design of the GKN nuclear reactor is different from the present BWR reactors because of some special features, such as the Natural Circulation - and the Passive Isolation Condenser system. When reviewing the design, one can conclude that the plant has 25 years of experience with check valves in passive systems and as passive components in systems. The result of this experience has been modeled in a plant-specific ``living PSA`` for the plant. A data-analysis has been performed on components which are related to the safety systems in the plant. As part of this study also the check valves have been taken in consideration. At GKN, the check valves have shown to be reliable components in the systems and no catastrophic failures have been experienced during the 25 years of operation. Especially the Isolation Condenser with its operation experience can contribute substantially to the insight of check valves in stand-by position at reactor pressure and operating by gravity under different pressure conditions. With the introduction of several passive systems in the SBWR-600 design, such as the Isolation Condensers, Gravity Driven Cooling, and Suppression Pool Cooling System, the issue of reliability of check valves in these systems is actual. Some critical aspects for study in connection with check valves are: What is the reliability of a check valve in a system at reactor pressure, to open on demand; what is the reliability of a check valve in a system at low pressure (gravity), to open on demand; what is the reliability of a check valve to open/close when the stand-by check wave is at zero differential pressure. The plant experience with check valves in a few essential safety systems is described and a brief introduction will be made about the application of check valves in the design of the new generation reactors is given. (author). 6 figs, 1 tab.

Aberrant leukocyte telomere length in Birdshot Uveitis.

Science.gov (United States)

Vazirpanah, Nadia; Verhagen, Fleurieke H; Rothova, Anna; Missotten, Tom O A R; van Velthoven, Mirjam; Den Hollander, Anneke I; Hoyng, Carel B; Radstake, Timothy R D J; Broen, Jasper C A; Kuiper, Jonas J W

2017-01-01

Birdshot Uveitis (BU) is an archetypical chronic inflammatory eye disease, with poor visual prognosis, that provides an excellent model for studying chronic inflammation. BU typically affects patients in the fifth decade of life. This suggests that it may represent an age-related chronic inflammatory disease, which has been linked to increased erosion of telomere length of leukocytes. To study this in detail, we exploited a sensitive standardized quantitative real-time polymerase chain reaction to determine the peripheral blood leukocyte telomere length (LTL) in 91 genotyped Dutch BU patients and 150 unaffected Dutch controls. Although LTL erosion rates were very similar between BU patients and healthy controls, we observed that BU patients displayed longer LTL, with a median of log (LTL) = 4.87 (= 74131 base pair) compared to 4.31 (= 20417 base pair) in unaffected controls (PRTEL1. These findings suggest that BU is accompanied by significantly longer LTL.

The influence of social anxiety on the body checking behaviors of female college students.

Science.gov (United States)

White, Emily K; Warren, Cortney S

2014-09-01

Social anxiety and eating pathology frequently co-occur. However, there is limited research examining the relationship between anxiety and body checking, aside from one study in which social physique anxiety partially mediated the relationship between body checking cognitions and body checking behavior (Haase, Mountford, & Waller, 2007). In an independent sample of 567 college women, we tested the fit of Haase and colleagues' foundational model but did not find evidence of mediation. Thus we tested the fit of an expanded path model that included eating pathology and clinical impairment. In the best-fitting path model (CFI=.991; RMSEA=.083) eating pathology and social physique anxiety positively predicted body checking, and body checking positively predicted clinical impairment. Therefore, women who endorse social physique anxiety may be more likely to engage in body checking behaviors and experience impaired psychosocial functioning. Published by Elsevier Ltd.

Sediment yield model implementation based on check dam infill stratigraphy in a semiarid Mediterranean catchment

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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.

Genetic determinants of leucocyte telomere length in children: a neglected and challenging field.

Science.gov (United States)

Stathopoulou, Maria G; Petrelis, Alexandros M; Buxton, Jessica L; Froguel, Philippe; Blakemore, Alexandra I F; Visvikis-Siest, Sophie

2015-03-01

Telomere length is associated with a large range of human diseases. Genome-wide association studies (GWAS) have identified genetic variants that are associated with leucocyte telomere length (LTL). However, these studies are limited to adult populations. Nevertheless, childhood is a crucial period for the determination of LTL, and the assessment of age-specific genetic determinants, although neglected, could be of great importance. Our aim was to provide insights and preliminary results on genetic determinants of LTL in children. Healthy children (n = 322, age range = 6.75-17 years) with available GWAS data (Illumina Human CNV370-Duo array) were included. The LTL was measured using multiplex quantitative real-time polymerase chain reaction. Linear regression models adjusted for age, gender, parental age at child's birth, and body mass index were used to test the associations of LTL with polymorphisms identified in adult GWAS and to perform a discovery-only GWAS. The previously GWAS-identified variants in adults were not associated with LTL in our paediatric sample. This lack of association was not due to possible interactions with age or gene × gene interactions. Furthermore, a discovery-only GWAS approach demonstrated six novel variants that reached the level of suggestive association (P ≤ 5 × 10(-5)) and explain a high percentage of children's LTL. The study of genetic determinants of LTL in children may identify novel variants not previously identified in adults. Studies in large-scale children populations are needed for the confirmation of these results, possibly through a childhood consortium that could better handle the methodological challenges of LTL genetic epidemiology field. © 2015 John Wiley & Sons Ltd.

Do alcohol compliance checks decrease underage sales at neighboring establishments?

Science.gov (United States)

Erickson, Darin J; Smolenski, Derek J; Toomey, Traci L; Carlin, Bradley P; Wagenaar, Alexander C

2013-11-01

Underage alcohol compliance checks conducted by law enforcement agencies can reduce the likelihood of illegal alcohol sales at checked alcohol establishments, and theory suggests that an alcohol establishment that is checked may warn nearby establishments that compliance checks are being conducted in the area. In this study, we examined whether the effects of compliance checks diffuse to neighboring establishments. We used data from the Complying with the Minimum Drinking Age trial, which included more than 2,000 compliance checks conducted at more than 900 alcohol establishments. The primary outcome was the sale of alcohol to a pseudo-underage buyer without the need for age identification. A multilevel logistic regression was used to model the effect of a compliance check at each establishment as well as the effect of compliance checks at neighboring establishments within 500 m (stratified into four equal-radius concentric rings), after buyer, license, establishment, and community-level variables were controlled for. We observed a decrease in the likelihood of establishments selling alcohol to underage youth after they had been checked by law enforcement, but these effects quickly decayed over time. Establishments that had a close neighbor (within 125 m) checked in the past 90 days were also less likely to sell alcohol to young-appearing buyers. The spatial effect of compliance checks on other establishments decayed rapidly with increasing distance. Results confirm the hypothesis that the effects of police compliance checks do spill over to neighboring establishments. These findings have implications for the development of an optimal schedule of police compliance checks.

Influence of check dams on debris-flow run-out intensity

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A. Remaître

2008-12-01

Full Text Available Debris flows are very dangerous phenomena claiming thousands of lives and millions of Euros each year over the world. Disaster mitigation includes non-structural (hazard mapping, insurance policies, active structural (drainage systems and passive structural (check dams, stilling basins countermeasures. Since over twenty years, many efforts are devoted by the scientific and engineering communities to the design of proper devices able to capture the debris-flow volume and/or break down the energy. If considerable theoretical and numerical work has been performed on the size, the shape and structure of check dams, allowing the definition of general design criteria, it is worth noting that less research has focused on the optimal location of these dams along the debris-flow pathway.

In this paper, a methodological framework is proposed to evaluate the influence of the number and the location of the check dams on the reduction of the debris-flow intensity (in term of flow thickness, flow velocity and volume. A debris-flow model is used to simulate the run-out of the debris flow. The model uses the Janbu force diagram to resolve the force equilibrium equations; a bingham fluid rheology is introduced and represents the resistance term. The model has been calibrated on two muddy debris-flow events that occurred in 1996 and 2003 at the Faucon watershed (South French Alps.

Influence of the check dams on the debris-flow intensity is quantified taking into account several check dams configurations (number and location as input geometrical parameters. Results indicate that debris-flow intensity is decreasing with the distance between the source area and the first check dams. The study demonstrates that a small number of check dams located near the source area may decrease substantially the debris-flow intensity on the alluvial fans.

Short leukocyte telomere length is associated with obesity in American Indians: the Strong Heart Family study.

Science.gov (United States)

Chen, Shufeng; Yeh, Fawn; Lin, Jue; Matsuguchi, Tet; Blackburn, Elizabeth; Lee, Elisa T; Howard, Barbara V; Zhao, Jinying

2014-05-01

Shorter leukocyte telomere length (LTL) has been associated with a wide range of age-related disorders including cardiovascular disease (CVD) and diabetes. Obesity is an important risk factor for CVD and diabetes. The association of LTL with obesity is not well understood. This study for the first time examines the association of LTL with obesity indices including body mass index, waist circumference, percent body fat, waist-to-hip ratio, and waist-to-height ratio in 3,256 American Indians (14-93 years old, 60% women) participating in the Strong Heart Family Study. Association of LTL with each adiposity index was examined using multivariate generalized linear mixed model, adjusting for chronological age, sex, study center, education, lifestyle (smoking, alcohol consumption, and total energy intake), high-sensitivity C-reactive protein, hypertension and diabetes. Results show that obese participants had significantly shorter LTL than non-obese individuals (age-adjusted P=0.0002). Multivariate analyses demonstrate that LTL was significantly and inversely associated with all of the studied obesity parameters. Our results may shed light on the potential role of biological aging in pathogenesis of obesity and its comorbidities.

Aberrant leukocyte telomere length in Birdshot Uveitis.

Directory of Open Access Journals (Sweden)

Nadia Vazirpanah

Full Text Available Birdshot Uveitis (BU is an archetypical chronic inflammatory eye disease, with poor visual prognosis, that provides an excellent model for studying chronic inflammation. BU typically affects patients in the fifth decade of life. This suggests that it may represent an age-related chronic inflammatory disease, which has been linked to increased erosion of telomere length of leukocytes.To study this in detail, we exploited a sensitive standardized quantitative real-time polymerase chain reaction to determine the peripheral blood leukocyte telomere length (LTL in 91 genotyped Dutch BU patients and 150 unaffected Dutch controls.Although LTL erosion rates were very similar between BU patients and healthy controls, we observed that BU patients displayed longer LTL, with a median of log (LTL = 4.87 (= 74131 base pair compared to 4.31 (= 20417 base pair in unaffected controls (P<0.0001. The cause underpinning the difference in LTL could not be explained by clinical parameters, immune cell-subtype distribution, nor genetic predisposition based upon the computed weighted genetic risk score of genotyped validated variants in TERC, TERT, NAF1, OBFC1 and RTEL1.These findings suggest that BU is accompanied by significantly longer LTL.

Pharmacist and Technician Perceptions of Tech-Check-Tech in Community Pharmacy Practice Settings.

Science.gov (United States)

Frost, Timothy P; Adams, Alex J

2018-04-01

Tech-check-tech (TCT) is a practice model in which pharmacy technicians with advanced training can perform final verification of prescriptions that have been previously reviewed for appropriateness by a pharmacist. Few states have adopted TCT in part because of the common view that this model is controversial among members of the profession. This article aims to summarize the existing research on pharmacist and technician perceptions of community pharmacy-based TCT. A literature review was conducted using MEDLINE (January 1990 to August 2016) and Google Scholar (January 1990 to August 2016) using the terms "tech* and check," "tech-check-tech," "checking technician," and "accuracy checking tech*." Of the 7 studies identified we found general agreement among both pharmacists and technicians that TCT in community pharmacy settings can be safely performed. This agreement persisted in studies of theoretical TCT models and in studies assessing participants in actual community-based TCT models. Pharmacists who had previously worked with a checking technician were generally more favorable toward TCT. Both pharmacists and technicians in community pharmacy settings generally perceived TCT to be safe, in both theoretical surveys and in surveys following actual TCT demonstration projects. These perceptions of safety align well with the actual outcomes achieved from community pharmacy TCT studies.

On the Complexity of Model-Checking Branching and Alternating-Time Temporal Logics in One-Counter Systems

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...

Deployment of check-in nodes in complex networks

Science.gov (United States)

Jiang, Zhong-Yuan; Ma, Jian-Feng

2017-01-01

In many real complex networks such as the city road networks and highway networks, vehicles often have to pass through some specially functioned nodes to receive check-in like services such as gas supplement at gas stations. Based on existing network structures, to guarantee every shortest path including at least a check-in node, the location selection of all check-in nodes is very essential and important to make vehicles to easily visit these check-in nodes, and it is still remains an open problem in complex network studies. In this work, we aim to find possible solutions for this problem. We first convert it into a set cover problem which is NP-complete and propose to employ the greedy algorithm to achieve an approximate result. Inspired by heuristic information of network structure, we discuss other four check-in node location deployment methods including high betweenness first (HBF), high degree first (HDF), random and low degree first (LDF). Finally, we compose extensive simulations in classical scale-free networks, random networks and real network models, and the results can well confirm the effectiveness of the greedy algorithm. This work has potential applications into many real networks.

Constraint-based deadlock checking of high-level specifications

DEFF Research Database (Denmark)

Hallerstede, Stefan; Leuschel, Michael

2011-01-01

Establishing the absence of deadlocks is important in many applications of formal methods. The use of model checking for finding deadlocks in formal models is limited because in many industrial applications the state space is either infinite or much too large to be explored exhaustively. In this ......Establishing the absence of deadlocks is important in many applications of formal methods. The use of model checking for finding deadlocks in formal models is limited because in many industrial applications the state space is either infinite or much too large to be explored exhaustively......B's Prolog kernel, such as reification of membership and arithmetic constraints. ProB typically finds counter examples to deadlock-freedom constraints, a formula of about 900 partly nested conjunctions and disjunction among them 80 arithmetic and 150 set-theoretic predicates (in total a formula of 30 pages...

Polymorphisms in Telomere Length Associated TERC and TERT predispose for Ischemic Stroke in a Chinese Han population.

Science.gov (United States)

Zhang, Shuo; Ji, Guofa; Liang, Yiqian; Zhang, Rui; Shi, Puyu; Guo, Dangshe; Li, Chunqi; Feng, Jing; Liu, Feng; Peng, Rong; Chen, Mingwei

2017-01-06

The role of telomere in genomic stability is an established fact. Variation in leukocyte telomere length (LTL) has been considered a crucial factor that associated with age-associated diseases. To elucidate the association between LTL variation and ischemic stroke (IS) risk, we selected ten single nucleotide polymorphisms (SNPs) in three genes (TERC, TERT and RTEL1) that previously reported link to LTL, and genotyped SNPs of these genes in a case-control study. The association between polymorphisms and IS risk were tested by Chi squared test and haplotype analysis. In allele association analysis, allele "C" in rs10936599 of TERC gene and allele "G" in rs2853677 of TERT gene were found to have an increased risk of IS when compared with allele "T" and "A", respectively. Model association analysis showed that genotype "G/A" in the overdominant model and genotypes "G/A" and "A/A" in the dominant model of rs2242652 presented a more likelihood to have IS. Another TERT locus (rs2853677) with genotype "G" was also found IS-related risky in the log-additive model. Taken together, our results suggest a potential association between LTL related TERC, TERT gene variants and ischemic stroke risk.

Repeated checking causes memory distrust

NARCIS (Netherlands)

van den Hout, M.; Kindt, M.

2003-01-01

This paper attempts to explain why in obsessive-compulsive disorder (OCD) checkers distrust in memory persists despite extensive checking. It is argued that: (1) repeated checking increases familiarity with the issues checked; (2) increased familiarity promotes conceptual processing which inhibits

CAPD Software Development for Automatic Piping System Design: Checking Piping Pocket, Checking Valve Level and Flexibility

International Nuclear Information System (INIS)

Ari Satmoko; Edi Karyanta; Dedy Haryanto; Abdul Hafid; Sudarno; Kussigit Santosa; Pinitoyo, A.; Demon Handoyo

2003-01-01

One of several steps in industrial plant construction is preparing piping layout drawing. In this drawing, pipe and all other pieces such as instrumentation, equipment, structure should be modeled A software called CAPD was developed to replace and to behave as piping drafter or designer. CAPD was successfully developed by adding both subprogram CHKUPIPE and CHKMANV. The first subprogram can check and gives warning if there is piping pocket in the piping system. The second can identify valve position and then check whether valve can be handled by operator hand The main program CAPD was also successfully modified in order to be capable in limiting the maximum length of straight pipe. By limiting the length, piping flexibility can be increased. (author)

A Formal Approach for RT-DVS Algorithms Evaluation Based on Statistical Model Checking

Directory of Open Access Journals (Sweden)

Shengxin Dai

2015-01-01

Full Text Available Energy saving is a crucial concern in embedded real time systems. Many RT-DVS algorithms have been proposed to save energy while preserving deadline guarantees. This paper presents a novel approach to evaluate RT-DVS algorithms using statistical model checking. A scalable framework is proposed for RT-DVS algorithms evaluation, in which the relevant components are modeled as stochastic timed automata, and the evaluation metrics including utilization bound, energy efficiency, battery awareness, and temperature awareness are expressed as statistical queries. Evaluation of these metrics is performed by verifying the corresponding queries using UPPAAL-SMC and analyzing the statistical information provided by the tool. We demonstrate the applicability of our framework via a case study of five classical RT-DVS algorithms.

What is a good health check? An interview study of health check providers' views and practices.

Science.gov (United States)

Stol, Yrrah H; Asscher, Eva C A; Schermer, Maartje H N

2017-10-02

Health checks identify (risk factors for) disease in people without symptoms. They may be offered by the government through population screenings and by other providers to individual users as 'personal health checks'. Health check providers' perspective of 'good' health checks may further the debate on the ethical evaluation and possible regulation of these personal health checks. In 2015, we interviewed twenty Dutch health check providers on criteria for 'good' health checks, and the role these criteria play in their practices. Providers unanimously formulate a number of minimal criteria: Checks must focus on (risk factors for) treatable/preventable disease; Tests must be reliable and clinically valid; Participation must be informed and voluntary; Checks should provide more benefits than harms; Governmental screenings should be cost-effective. Aspirational criteria mentioned were: Follow-up care should be provided; Providers should be skilled and experienced professionals that put the benefit of (potential) users first; Providers should take time and attention. Some criteria were contested: People should be free to test on any (risk factor for) disease; Health checks should only be performed in people at high risk for disease that are likely to implement health advice; Follow up care of privately funded tests should not drain on collective resources. Providers do not always fulfil their own criteria. Their reasons reveal conflicts between criteria, conflicts between criteria and other ethical values, and point to components in the (Dutch) organisation of health care that hinder an ethical provision of health checks. Moreover, providers consider informed consent a criterion that is hard to establish in practice. According to providers, personal health checks should meet the same criteria as population screenings, with the exception of cost-effectiveness. Providers do not always fulfil their own criteria. Results indicate that in thinking about the ethics of health

SOLA-LOOP analysis of a back pressure check valve

International Nuclear Information System (INIS)

Travis, J.R.

1984-01-01

The SOLA-LOOP computer code for transient, nonequilibrium, two-phase flows in networks has been coupled with a simple valve model to analyze a feedwater pipe breakage with a back-pressure check valve. Three tests from the Superheated Steam Reactor Safety Program Project (PHDR) at Kahl, West Germany, are analyzed, and the calculated transient back-pressure check valve behavior and fluid dynamics effects are found to be in excellent agreement with the experimentally measured data

Check valves aging assessment

International Nuclear Information System (INIS)

Haynes, H.D.

1991-01-01

In support of the NRC Nuclear Plant Aging Research (NPAR) program, the Oak Ridge National Laboratory (ORNL) has carried out an assessment of several check value diagnostic monitoring methods, in particular, those based on measurements of acoustic emission, ultrasonics, and magnetic flux. The evaluations have focussed on the capabilities of each method to provide information useful in determining check valve aging and service wear effects, check valve failures, and undesirable operating modes. This paper describes the benefits and limitations associated with each method and includes recent laboratory and field test data, including data obtained from the vendors who recently participated in a comprehensive series of tests directed by a nuclear industry users group. In addition, as part of the ORNL Advanced Diagnostic Engineering Research and Development Center (ADEC), two novel nonintrusive monitoring methods were developed that provide several unique capabilities. These methods, based on external ac- an dc-magnetic monitoring are also described. None of the examined methods could, by themselves, monitor both the instantaneous position and motion of check valve internals and valve leakage; however, the combination of acoustic emission monitoring with one of the other methods provides the means to determine vital check valve operational information

27 CFR 70.101 - Bad checks.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Bad checks. 70.101 Section....101 Bad checks. If any check or money order in payment of any amount receivable under Title 26 of the... appropriate TTB officer that such check was tendered in good faith and that such person had reasonable cause...

Check In / Check Out. The Public Space as an Internet of Things

NARCIS (Netherlands)

van t Hof, C.C.G.; van Est, R.; Daemen, F.

2011-01-01

Mobile phones, public transport smart cards, security cameras and GPS systems in our car - we are surrounded by digital devices. They track us, guide us, help us, and control us. The book Check In / Check Out. The Public Space as an Internet of Things shows us how our digital and physical worlds are

Check in / check out : the public space as an internet of things

NARCIS (Netherlands)

Hof, van 't C.; Est, van R.; Daemen, F.

2011-01-01

Mobile phones, public transport smart cards, security cameras and GPS systems in our car - we are surrounded by digital devices. They track us, guide us, help us, and control us. The book Check In / Check Out. The Public Space as an Internet of Things shows us how our digital and physical worlds are

What is a good health check? An interview study of health check providers' views and practices

NARCIS (Netherlands)

Y. Stol (Yrrah); E.C.A. Asscher (Eva); M.H.N. Schermer (Maartje)

2017-01-01

markdownabstract__Background:__ Health checks identify (risk factors for) disease in people without symptoms. They may be offered by the government through population screenings and by other providers to individual users as 'personal health checks'. Health check providers' perspective of 'good'

checkCIF/PLATON (full publication check)

Indian Academy of Sciences (India)

editor handling your paper, to upload your CIF via our web site. PLATON version of 05/02/2014; check.def file version of 05/02/2014. Datablock I - ellipsoid plot http://vm02b.iucr.org/cgi-bin/checkcif_hkl.pl（第 3／4 页）2014-2-12 09:09:12 ...

Effects of size at birth, childhood growth patterns and growth hormone treatment on leukocyte telomere length.

Directory of Open Access Journals (Sweden)

Carolina C J Smeets

Full Text Available Small size at birth and rapid growth in early life are associated with increased risk of cardiovascular disease in later life. Short children born small for gestational age (SGA are treated with growth hormone (GH, inducing catch-up in length. Leukocyte telomere length (LTL is a marker of biological age and shorter LTL is associated with increased risk of cardiovascular disease.To investigate whether LTL is influenced by birth size, childhood growth and long-term GH treatment.We analyzed LTL in 545 young adults with differences in birth size and childhood growth patterns. Previously GH-treated young adults born SGA (SGA-GH were compared to untreated short SGA (SGA-S, SGA with spontaneous catch-up to a normal body size (SGA-CU, and appropriate for gestational age with a normal body size (AGA-NS. LTL was measured using a quantitative PCR assay.We found a positive association between birth length and LTL (p = 0.04, and a trend towards a positive association between birth weight and LTL (p = 0.08, after adjustments for gender, age, gestational age and adult body size. Weight gain during infancy and childhood and fat mass percentage were not associated with LTL. Female gender and gestational age were positively associated with LTL, and smoking negatively. After adjustments for gender, age and gestational age, SGA-GH had a similar LTL as SGA-S (p = 0.11, SGA-CU (p = 0.80, and AGA-NS (p = 0.30.Larger size at birth is positively associated with LTL in young adulthood. Growth patterns during infancy and childhood are not associated with LTL. Previously GH-treated young adults born SGA have similar LTL as untreated short SGA, SGA with spontaneous catch-up and AGA born controls, indicating no adverse effects of GH-induced catch-up in height on LTL.

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.

Luteolin Inhibits Tumorigenesis and Induces Apoptosis of Non-Small Cell Lung Cancer Cells via Regulation of MicroRNA-34a-5p

Directory of Open Access Journals (Sweden)

Ze-Qun Jiang

2018-02-01

Full Text Available Luteolin (LTL exerts remarkable tumor suppressive activity on various types of cancers, including non-small cell lung cancer (NSCLC. However, it is not completely understood whether the mechanism of its action against NSCLC is related to microRNAs (miRNAs. In the present study, we investigated the anti-tumor effects of LTL on NSCLC in vitro and in vivo. The results revealed that LTL could inhibit cell proliferation and induce apoptosis in both A549 and H460 cells. In a H460 xenograft tumor model of nude mice, LTL significantly suppressed tumor growth, inhibited cell proliferation, and induced apoptosis. miRNA microarray and quantitative PCR (qPCR analysis indicated that miR-34a-5p was dramatically upregulated upon LTL treatment in tumor tissues. Furthermore, MDM4 was proved to be a direct target of miR-34a-5p by luciferase reporter gene assay. LTL treatment was associated with increased p53 and p21 protein expressions and decreased MDM4 protein expression in both NSCLC cells and tumor tissues. When miR-34a-5p was inhibited in vitro, the protein expressions of Bcl-2 and MDM4 were recovered, while that of p53, p21, and Bax were attenuated. Moreover, caspase-3 and caspase-9 activation induced by LHL treatment in vitro were also suppressed by miR-34a-5p inhibition. Overall, LTL could inhibit tumorigenesis and induce apoptosis of NSCLC cells by upregulation of miR-34a-5p via targeting MDM4. These findings provide novel insight into the molecular functions of LTL that suggest its potential as a therapeutic agent for human NSCLC.

Space shuttle prototype check valve development

Science.gov (United States)

Tellier, G. F.

1976-01-01

Contaminant-resistant seal designs and a dynamically stable prototype check valve for the orbital maneuvering and reaction control helium pressurization systems of the space shuttle were developed. Polymer and carbide seal models were designed and tested. Perfluoroelastomers compatible with N2O4 and N2H4 types were evaluated and compared with Teflon in flat and captive seal models. Low load sealing and contamination resistance tests demonstrated cutter seal superiority over polymer seals. Ceramic and carbide materials were evaluated for N2O4 service using exposure to RFNA as a worst case screen; chemically vapor deposited tungsten carbide was shown to be impervious to the acid after 6 months immersion. A unique carbide shell poppet/cutter seat check valve was designed and tested to demonstrate low cracking pressure ( 2.0 psid), dynamic stability under all test bench flow conditions, contamination resistance (0.001 inch CRES wires cut with 1.5 pound seat load) and long life of 100,000 cycles (leakage 1.0 scc/hr helium from 0.1 to 400 psig).

Verification of communication protocols in web services model-checking service compositions

CERN Document Server

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.

checkCIF/PLATON report Datablock: shelxl

Indian Academy of Sciences (India)

6 ALERT level G = General information/check it is not something unexpected. 1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data. 15 ALERT type 2 Indicator that the structure model may be wrong or deficient. 9 ALERT type 3 Indicator that the structure quality may be low. 1 ALERT type 4 Improvement, ...

Type Checking with XML Schema in XACT

DEFF Research Database (Denmark)

Kirkegaard, Christian; Møller, Anders

to support XML Schema as type formalism. The technique is able to model advanced features, such as type derivations and overloaded local element declarations, and also datatypes of attribute values and character data. Moreover, we introduce optional type annotations to improve modularity of the type checking...

Enabling model checking for collaborative process analysis: from BPMN to `Network of Timed Automata'

Science.gov (United States)

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.

Modelling of coupled self-actuating safety, relief and damped check valve systems with the codes TRAC-PF1 and ROLAST

International Nuclear Information System (INIS)

Neumann, U.; Puzalowski, R.; Grimm, I.

1985-01-01

Numerical valve models for simulation of selfactuating safety valves and damped check valves are introduced for the computer programs TRAC-PF1 and ROLAST. As examples of application post-test calculations and stability analysis are given. (orig.)

Automated Formal Verification for PLC Control Systems

CERN Multimedia

Fernández Adiego, Borja

2014-01-01

Programmable Logic Controllers (PLCs) are widely used devices used in industrial control systems. Ensuring that the PLC software is compliant with its specification is a challenging task. Formal verification has become a recommended practice to ensure the correctness of the safety-critical software. However, these techniques are still not widely applied in industry due to the complexity of building formal models, which represent the system and the formalization of requirement specifications. We propose a general methodology to perform automated model checking of complex properties expressed in temporal logics (e.g. CTL, LTL) on PLC programs. This methodology is based on an Intermediate Model (IM), meant to transform PLC programs written in any of the languages described in the IEC 61131-3 standard (ST, IL, etc.) to different modeling languages of verification tools. This approach has been applied to CERN PLC programs validating the methodology.

Role of recent research in improving check valve reliability at nuclear power plants

International Nuclear Information System (INIS)

Kalsi, M.S.; Horst, C.L.; Wang, J.K.; Sharma, V.

1990-01-01

Check valve failures at nuclear power plants in recent years have led to serious safety concerns, and caused extensive damage to other plant components which had a significant impact on plant availability. In order to understand the failure mechanism and improve the reliability of check valves, a systematic research effort was proposed by Kalsi Engineering, Inc. to U.S. Nuclear Regulatory Commission (NRC). The overall goal of the research was to develop models for predicting the performance and degradation of swing check valves in nuclear power plant systems so that appropriate preventive maintenance or design modifications can be performed to improve the reliability of check valves. Under Phase I of this research, a large matrix of tests was run with instrumented swing check valves to determine the stability of the disc under a variety of upstream flow disturbances, covering a wide range of disc stop positions and flow velocities in two different valve sizes. The goals of Phase II research were to develop predictive models which quantify the anticipated degradation of swing check valves that have flow disturbances closely upstream of the valve and are operating under flow velocities that do not result in full disc opening. This research allows the inspection/maintenance activities to be focussed on those check valves that are more likely to suffer premature degradation. The quantitative wear and fatigue prediction methodology can be used to develop a sound preventive maintenance program. The results of the research also show the improvements in check valve performance/reliability that can be achieved by certain modifications in the valve design

The method of a joint intraday security check system based on cloud computing

Science.gov (United States)

Dong, Wei; Feng, Changyou; Zhou, Caiqi; Cai, Zhi; Dan, Xu; Dai, Sai; Zhang, Chuancheng

2017-01-01

The intraday security check is the core application in the dispatching control system. The existing security check calculation only uses the dispatch center’s local model and data as the functional margin. This paper introduces the design of all-grid intraday joint security check system based on cloud computing and its implementation. To reduce the effect of subarea bad data on the all-grid security check, a new power flow algorithm basing on comparison and adjustment with inter-provincial tie-line plan is presented. And the numerical example illustrated the effectiveness and feasibility of the proposed method.

Online Conformance Checking for Petri Nets and Event Streams

DEFF Research Database (Denmark)

Burattin, Andrea

2017-01-01

Within process mining, we can identify conformance checking as the task of computing the extent to which executions of a process model are in line with the reference behavior. Most approaches currently available in the literature (for imperative models, such as Petri nets) perform just a-posterio...

Tracking and fixed ranking of leukocyte telomere length across the adult life course

DEFF Research Database (Denmark)

Benetos, Athanase; Kark, Jeremy D; Susser, Ezra

2013-01-01

whether age-dependent LTL attrition during adulthood can substantially affect individuals' LTL ranking (e.g., longer or shorter LTL) in relation to their peers. We measured LTL in samples donated 12 years apart on average by 1156 participants in four longitudinal studies. We observed correlations of 0.......91-0.96 between baseline and follow-up LTLs. Ranking individuals by deciles revealed that 94.1% (95% confidence interval of 92.6-95.4%) showed no rank change or a 1 decile change over time. We conclude that in adults, LTL is virtually anchored to a given rank with the passage of time. Accordingly, the links...... of LTL with atherosclerosis and longevity appear to be established early in life. It is unlikely that lifestyle and its modification during adulthood exert a major impact on LTL ranking....

Software tool for physics chart checks.

Science.gov (United States)

Li, H Harold; Wu, Yu; Yang, Deshan; Mutic, Sasa

2014-01-01

Physics chart check has long been a central quality assurance (QC) measure in radiation oncology. The purpose of this work is to describe a software tool that aims to accomplish simplification, standardization, automation, and forced functions in the process. Nationally recognized guidelines, including American College of Radiology and American Society for Radiation Oncology guidelines and technical standards, and the American Association of Physicists in Medicine Task Group reports were identified, studied, and summarized. Meanwhile, the reported events related to physics chart check service were analyzed using an event reporting and learning system. A number of shortfalls in the chart check process were identified. To address these problems, a software tool was designed and developed under Microsoft. Net in C# to hardwire as many components as possible at each stage of the process. The software consists of the following 4 independent modules: (1) chart check management; (2) pretreatment and during treatment chart check assistant; (3) posttreatment chart check assistant; and (4) quarterly peer-review management. The users were a large group of physicists in the author's radiation oncology clinic. During over 1 year of use the tool has proven very helpful in chart checking management, communication, documentation, and maintaining consistency. The software tool presented in this work aims to assist physicists at each stage of the physics chart check process. The software tool is potentially useful for any radiation oncology clinics that are either in the process of pursuing or maintaining the American College of Radiology accreditation.

25 CFR 115.704 - May we accept for deposit into a trust account retirement checks/payments or pension fund checks...

Science.gov (United States)

2010-04-01

... checks/payments or pension fund checks/payments even though those funds are not specified in § 115.702... May we accept for deposit into a trust account retirement checks/payments or pension fund checks.../payments or pension fund checks/payments or any funds from sources that are not identified in the table in...

Application of risk-based methods to inservice testing of check valves

Energy Technology Data Exchange (ETDEWEB)

Closky, N.B.; Balkey, K.R.; McAllister, W.J. [and others

1996-12-01

Research efforts have been underway in the American Society of Mechanical Engineers (ASME) and industry to define appropriate methods for the application of risk-based technology in the development of inservice testing (IST) programs for pumps and valves in nuclear steam supply systems. This paper discusses a pilot application of these methods to the inservice testing of check valves in the emergency core cooling system of Georgia Power`s Vogtle nuclear power station. The results of the probabilistic safety assessment (PSA) are used to divide the check valves into risk-significant and less-risk-significant groups. This information is reviewed by a plant expert panel along with the consideration of appropriate deterministic insights to finally categorize the check valves into more safety-significant and less safety-significant component groups. All of the more safety-significant check valves are further evaluated in detail using a failure modes and causes analysis (FMCA) to assist in defining effective IST strategies. A template has been designed to evaluate how effective current and emerging tests for check valves are in detecting failures or in finding significant conditions that are precursors to failure for the likely failure causes. This information is then used to design and evaluate appropriate IST strategies that consider both the test method and frequency. A few of the less safety-significant check valves are also evaluated using this process since differences exist in check valve design, function, and operating conditions. Appropriate test strategies are selected for each check valve that has been evaluated based on safety and cost considerations. Test strategies are inferred from this information for the other check valves based on similar check valve conditions. Sensitivity studies are performed using the PSA model to arrive at an overall IST program that maintains or enhances safety at the lowest achievable cost.

[Pre-verbality in focusing and the need for self check. An attempt at "focusing check"].

Science.gov (United States)

Masui, T; Ikemi, A; Murayama, S

1983-06-01

Though the Focusing process is not entirely non-verbal, in Focusing, careful attention is paid by the Focuser and the Listener to the pre-verbal experiential process. In other words, Focusing involves attending to the felt sense that is not easily expressed in words immediately. Hence, during the process of learning to Focus, the Focusing teacher attempts to communicate the experiences of Focusing to the student which are not easily done by words. Due to such difficulties, the Focusing student may (and quite frequently does) mistake the experiential process in Focusing with other processes. Often, the felt sense can be confused with other phenomena such as "autogenic discharge". Also the Focuser may not stay with the felt sense and drift into "free association" or frequently, certain processes in "meditation" can be confused with Focusing. Therefore, there is a need for a "check" by which the Focusing student can confirm the Focusing experience for himself. For the Focusing student, such a "check" serves not only to confirm the Focusing process, but also an aid to learning Focusing. We will report here a "Focusing Check" which we developed by translating Eugene Gendlin's "Focusing Check" and making several modifications in it so that it will be more understandable to the Japanese. Along with the "Focusing Check" we developed, the authors discuss the need for such a check.

Estimated emission reductions from California's enhanced Smog Check program.

Science.gov (United States)

Singer, Brett C; Wenzel, Thomas P

2003-06-01

The U.S. Environmental Protection Agency requires that states evaluate the effectiveness of their vehicle emissions inspection and maintenance (I/M) programs. This study demonstrates an evaluation approach that estimates mass emission reductions over time and includes the effect of I/M on vehicle deterioration. It includes a quantitative assessment of benefits from pre-inspection maintenance and repairs and accounts for the selection bias effect that occurs when intermittent high emitters are tested. We report estimates of one-cycle emission benefits of California's Enhanced Smog Check program, ca. 1999. Program benefits equivalent to metric tons per day of prevented emissions were calculated with a "bottom-up" approach that combined average per vehicle reductions in mass emission rates (g/gal) with average per vehicle activity, resolved by model year. Accelerated simulation mode test data from the statewide vehicle information database (VID) and from roadside Smog Check testing were used to determine 2-yr emission profiles of vehicles passing through Smog Check and infer emission profiles that would occur without Smog Check. The number of vehicles participating in Smog Check was also determined from the VID. We estimate that in 1999 Smog Check reduced tailpipe emissions of HC, CO, and NO(x) by 97, 1690, and 81 t/d, respectively. These correspond to 26, 34, and 14% of the HC, CO, and NO(x) that would have been emitted by vehicles in the absence of Smog Check. These estimates are highly sensitive to assumptions about vehicle deterioration in the absence of Smog Check. Considering the estimated uncertainty in these assumptions yields a range for calculated benefits: 46-128 t/d of HC, 860-2200 t/d of CO, and 60-91 t/d of NO(x). Repair of vehicles that failed an initial, official Smog Check appears to be the most important mechanism of emission reductions, but pre-inspection maintenance and repair also contributed substantially. Benefits from removal of nonpassing

[Infection prevention check-in and infection prevention check-out to prevent nosocomial infections].

Science.gov (United States)

Kramer, A; Schilling, M; Heidecke, C D

2010-02-01

A precondition for the success of the prevention of SSI is the complete realisation of the proven anti-infective measures in form of the multi-barrier strategy or the so-called bundles. In daily practice it is important to follow the fixed instructions, i. e., to ensure a high compliance. In much the same way as an airline pilot or co-pilot must examine whether all instruments are functioning before each take-off, a comparable procedure should be developed as a pre-operative control for the observance of all -defined measures by the responsible surgeon and for the post-operative supervision by the patient. For the control of the observance of the defined pre-operative prevention measures, a check list with 12 items was developed, named the "infection prevention check-in". The check list is authorised by the responsible surgeon be-fore each operation. For the surveillance of the general hygiene in the post-operative period the "infection prevention check-out" with 14 items was developed. Thereby the patient is able to evaluate the staff's compliance with the hygienic measures at the time of dismissal. With the introduction of the check-lists a simple means is given to involve both the team of the surgeons and the ward staff, together with the patient, into the infection prophylaxis even more effectively. In order to assess the success of those measures, the influence on the rate of SSI is to be determined prospectively. Georg Thieme Verlag Stuttgart, New York.

QuickChecking static analysis properties

DEFF Research Database (Denmark)

Midtgaard, Jan; Møller, Anders

2017-01-01

A static analysis can check programs for potential errors. A natural question that arises is therefore: who checks the checker? Researchers have given this question varying attention, ranging from basic testing techniques, informal monotonicity arguments, thorough pen-and-paper soundness proofs....... Moreover, we offer a number of generic, type-safe combinators to check transfer functions and operators on lattices, to help ensure that these are, eg, monotone, strict, or invariant. We substantiate our claims by quickchecking a type analysis for the Lua programming language....

Simple Check Valves for Microfluidic Devices

Science.gov (United States)

Willis, Peter A.; Greer, Harold F.; Smith, J. Anthony

2010-01-01

A simple design concept for check valves has been adopted for microfluidic devices that consist mostly of (1) deformable fluorocarbon polymer membranes sandwiched between (2) borosilicate float glass wafers into which channels, valve seats, and holes have been etched. The first microfluidic devices in which these check valves are intended to be used are micro-capillary electrophoresis (microCE) devices undergoing development for use on Mars in detecting compounds indicative of life. In this application, it will be necessary to store some liquid samples in reservoirs in the devices for subsequent laboratory analysis, and check valves are needed to prevent cross-contamination of the samples. The simple check-valve design concept is also applicable to other microfluidic devices and to fluidic devices in general. These check valves are simplified microscopic versions of conventional rubber- flap check valves that are parts of numerous industrial and consumer products. These check valves are fabricated, not as separate components, but as integral parts of microfluidic devices. A check valve according to this concept consists of suitably shaped portions of a deformable membrane and the two glass wafers between which the membrane is sandwiched (see figure). The valve flap is formed by making an approximately semicircular cut in the membrane. The flap is centered over a hole in the lower glass wafer, through which hole the liquid in question is intended to flow upward into a wider hole, channel, or reservoir in the upper glass wafer. The radius of the cut exceeds the radius of the hole by an amount large enough to prevent settling of the flap into the hole. As in a conventional rubber-flap check valve, back pressure in the liquid pushes the flap against the valve seat (in this case, the valve seat is the adjacent surface of the lower glass wafer), thereby forming a seal that prevents backflow.

Mitigating check valve slamming and subsequentwater hammer events for PPFS using MOC

International Nuclear Information System (INIS)

Tian Wenxi; Su Guanghui; Wang Gaopeng; Qiu Suizheng; Xiao Zejun

2009-01-01

The method of characteristic (MOC) was adopted to analyze the check valve-induced water hammer behaviors for a Parallel Pumps Feedwater System (PPFS) during the alternate startup process. The motion of check valve disc was simulated using inertial valve model. Transient parameters including the pressure oscillation, local flow velocity and slamming of the check valve disc etc. have been obtained. The results showed that severe slamming between the valve disc and valve seat occurred during the alternate startup of parallel pumps. The induced maximum pressure vibration amplitude is up to 5.0 MPa. The scheme of appending a damping torque to slow down the check valve closing speed was also performed to mitigate of water hammer. It has been numerically approved to be an effective approach. (authors)

Mitigating check valve slamming and subsequentwater hammer events for PPFS using MOC

Institute of Scientific and Technical Information of China (English)

TIAN Wenxi; SU Guanghui; WANG Gaopeng; QIU Suizheng; XIAO Zejun

2009-01-01

The method of characteristic (MOC) was adopted to analyze the check valve-induced water hammer behaviors for a Parallel Pumps Feedwater System (PPFS) during the alternate startup process. The motion of check valve disc was simulated using inertial valve model. Transient parameters including the pressure oscillation, local flow velocity and slamming of the check valve disc etc. have been obtained. The results showed that severe slamming between the valve disc and valve seat occurred during the alternate startup of parallel pumps. The induced maximum pressure vibration amplitude is up to 5.0 MPa. The scheme of appending a damping torque to slow down the check valve closing speed was also performed to mitigate of water hammer. It has been numerically approved to be an effective approach.

Model Checking Artificial Intelligence Based Planners: Even the Best Laid Plans Must Be Verified

Science.gov (United States)

Smith, Margaret H.; Holzmann, Gerard J.; Cucullu, Gordon C., III; Smith, Benjamin D.

2005-01-01

Automated planning systems (APS) are gaining acceptance for use on NASA missions as evidenced by APS flown On missions such as Orbiter and Deep Space 1 both of which were commanded by onboard planning systems. The planning system takes high level goals and expands them onboard into a detailed of action fiat the spacecraft executes. The system must be verified to ensure that the automatically generated plans achieve the goals as expected and do not generate actions that would harm the spacecraft or mission. These systems are typically tested using empirical methods. Formal methods, such as model checking, offer exhaustive or measurable test coverage which leads to much greater confidence in correctness. This paper describes a formal method based on the SPIN model checker. This method guarantees that possible plans meet certain desirable properties. We express the input model in Promela, the language of SPIN and express the properties of desirable plans formally.

25 CFR 11.421 - Bad checks.

Science.gov (United States)

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false Bad checks. 11.421 Section 11.421 Indians BUREAU OF... Criminal Offenses § 11.421 Bad checks. (a) A person who issues or passes a check or similar sight order for..., and the issuer failed to make good within 10 days after receiving notice of that refusal. ...

QuickChecking Static Analysis Properties

DEFF Research Database (Denmark)

Midtgaard, Jan; Møller, Anders

2015-01-01

A static analysis can check programs for potential errors. A natural question that arises is therefore: who checks the checker? Researchers have given this question varying attention, ranging from basic testing techniques, informal monotonicity arguments, thorough pen-and-paper soundness proofs...... of a lattice. Moreover, we offer a number of generic, type-safe combinators to check transfer functions and operators on lattices, to help ensure that these are, e.g., monotone, strict, or invariant. We substantiate our claims by quickchecking a type analysis for the Lua programming language...

From preventive to permissive checks

DEFF Research Database (Denmark)

Weisdorf, Jacob Louis; Sharp, Paul Richard

2009-01-01

The Malthusian "preventive check" mechanism has been well documented for pre-industrial England through evidence for a negative correlation between the marriage rate and the price of wheat. Other literature, however, speculates that the correlation was in fact positive from the early nineteenth c...... model shows that this result is not in fact inconsistent with a stylised Malthusian mechanism, and can be understood within the context of an increasing dominance of shocks to aggregate demand rather than to aggregate supply....

A Game-Theoretic Approach to Branching Time Abstract-Check-Refine Process

Science.gov (United States)

Wang, Yi; Tamai, Tetsuo

2009-01-01

Since the complexity of software systems continues to grow, most engineers face two serious problems: the state space explosion problem and the problem of how to debug systems. In this paper, we propose a game-theoretic approach to full branching time model checking on three-valued semantics. The three-valued models and logics provide successful abstraction that overcomes the state space explosion problem. The game style model checking that generates counter-examples can guide refinement or identify validated formulas, which solves the system debugging problem. Furthermore, output of our game style method will give significant information to engineers in detecting where errors have occurred and what the causes of the errors are.

Diagnostic information in compliance checking

NARCIS (Netherlands)

Ramezani Taghiabadi, E.; Fahland, D.; Aalst, van der W.M.P.

2012-01-01

Compliance checking is gaining importance as today's organizations need to show that operational processes are executed in a controlled manner while satisfying predefined (legal) requirements. Deviations may be costly and expose the organization to severe risks. Compliance checking is of growing

Implementing Check in/Check out for Students with Intellectual Disability in Self-Contained Classrooms

Science.gov (United States)

Boden, Lauren J.; Ennis, Robin P.; Jolivette, Kristine

2012-01-01

Check in/check out (CICO) is a secondary-tier intervention implemented within the framework of schoolwide positive behavior interventions and supports (SWPBIS) that uses school-based contingencies to encourage positive behavior. CICO is a five-step cycle which uses daily progress report cards (DPR) to monitor progress toward schoolwide or…

Inference on population history and model checking using DNA sequence and microsatellite data with the software DIYABC (v1.0

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

Learning Markov models for stationary system behaviors

DEFF Research Database (Denmark)

Chen, Yingke; Mao, Hua; Jaeger, Manfred

2012-01-01

to a single long observation sequence, and in these situations existing automatic learning methods cannot be applied. In this paper, we adapt algorithms for learning variable order Markov chains from a single observation sequence of a target system, so that stationary system properties can be verified using......Establishing an accurate model for formal verification of an existing hardware or software system is often a manual process that is both time consuming and resource demanding. In order to ease the model construction phase, methods have recently been proposed for automatically learning accurate...... the learned model. Experiments demonstrate that system properties (formulated as stationary probabilities of LTL formulas) can be reliably identified using the learned model....

Sedentary behavior, physical activity and cardiorespiratory fitness on leukocyte telomere length.

Science.gov (United States)

Edwards, Meghan K; Loprinzi, Paul D

2017-01-01

Background: Emerging work is starting to investigate the cumulative effects of moderate-to-vigorous physical activity (MVPA), sedentary behavior and cardiorespiratory fitness on health. The objective of this study was to examine the cumulative and independent associations of MVPA, sedentary behavior and cardiorespiratory fitness on leukocyte telomere length (LTL). Methods: Data from the 1999-2002 National Health and Nutrition Examination Survey (NHANES) were used (N = 1868 adults 20+ years); analyzed in 2016. Sedentary behavior and MVPA were subjectively assessed with cardiorespiratory fitness determined from a submaximal treadmill-based test; participants were classified as above or below the median values for each of these three parameters. A blood sample was obtained from each participant to assess LTL via quantitative polymerase chain reaction, with participants grouped into LTL tertiles. Results: Participants who engaged in higher MVPA, sat less and had higher cardiorespiratory fitness had an increased odds (ranging from 85% to 105%) of being in LTL tertile 3 (vs. 1). In an extended adjusted multinomial logistic regression model, only MVPA was positively associated with LTL (odds ration [OR] = 1.37; 95% CI: 0.99-1.90; P = 0.05). Conclusion: All three behavior characteristics, but particularly MVPA, may be important in preserving LTLs.

XML-based formulation of field theoretical models. A proposal for a future standard and data base for model storage, exchange and cross-checking of results

International Nuclear Information System (INIS)

Demichev, A.; Kryukov, A.; Rodionov, A.

2002-01-01

We propose an XML-based standard for formulation of field theoretical models. The goal of creation of such a standard is to provide a way for an unambiguous exchange and cross-checking of results of computer calculations in high energy physics. At the moment, the suggested standard implies that models under consideration are of the SM or MSSM type (i.e., they are just SM or MSSM, their submodels, smooth modifications or straightforward generalizations). (author)

Goat production check list

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....

12 CFR Appendix A to Part 229 - Routing Number Guide to Next-Day Availability Checks and Local Checks

Science.gov (United States)

2010-01-01

... Checks and Local Checks A Appendix A to Part 229 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM AVAILABILITY OF FUNDS AND COLLECTION OF CHECKS... Association. The routing number takes two forms: a fractional form and a nine-digit form. A paying bank...

Can i just check...? Effects of edit check questions on measurement error and survey estimates

NARCIS (Netherlands)

Lugtig, Peter; Jäckle, Annette

2014-01-01

Household income is difficult to measure, since it requires the collection of information about all potential income sources for each member of a household.Weassess the effects of two types of edit check questions on measurement error and survey estimates: within-wave edit checks use responses to

Scram system with continuos check

International Nuclear Information System (INIS)

Rodriguez Sacco, Walter.

1976-02-01

The equipment described pretends to be a further step to the use of integrated circuits in nuclear instrumentation, considering that this type of control was traditionally carried out on the bases of electromechanical elements. A continuous self-check method has been applied in accordance with the high reliability requiered for this type of equipments. The developed equipment fulfils the condition that any deficiency in its component elements, causes an anormal self-detected operation. The equipment covers two systems: the Scram one, that includes the sequence generator-detector, the rods check and scram chain, and the Check system that uses pulses from the sequence detector. (author) [es

Childhood Personality, Betrayal Trauma, and Leukocyte Telomere Length in Adulthood: A Lifespan Perspective on Conscientiousness and Betrayal Traumas as Predictors of a Biomarker of Cellular Aging.

Science.gov (United States)

Edmonds, Grant W; Hampson, Sarah E; Côté, Hélène C F; Hill, Patrick L; Klest, Bridget

2016-01-01

Conscientiousness is associated with longevity. As such, identifying the biological pathways linking personality to mortality is important. This study employs longitudinal data spanning >40 years to test prospective associations with Leukocyte Telomere Length (LTL), a potential marker of cellular aging. Because telomeres shorten over time, and are sensitive to oxidative stress, shorter LTL may reflect cumulative damage associated with negative health behaviors and past stressful events. We investigated childhood conscientiousness as a protective factor, expecting an association with longer LTL in adulthood, possibly reflecting slower LTL shortening. Potential lifespan pathways involving childhood trauma, smoking behaviors, and Body Mass Index (BMI) were explored. Childhood conscientiousness showed a small raw association with LTL ( r = .08, p = .04), although this effect did not persist when controlling for age and sex. Despite this lack of a direct effect on LTL, we detected an indirect effect operating jointly through BMI and smoking. Higher rates of childhood betrayal trauma were associated with shorter LTL. Contrary to our hypothesis that conscientiousness would buffer this effect, we found evidence for an interaction with childhood betrayal traumas where the association between childhood betrayal traumas and LTL was larger for those higher on conscientiousness in childhood.

Depressive and anxiety disorders and short leukocyte telomere length: mediating effects of metabolic stress and lifestyle factors.

Science.gov (United States)

Révész, D; Verhoeven, J E; Milaneschi, Y; Penninx, B W J H

2016-08-01

Depressive and anxiety disorders are associated with shorter leukocyte telomere length (LTL), an indicator of cellular aging. It is, however, unknown which pathways underlie this association. This study examined the extent to which lifestyle factors and physiological changes such as inflammatory or metabolic alterations mediate the relationship. We applied mediation analysis techniques to data from 2750 participants of the Netherlands Study of Depression and Anxiety. LTL was assessed using quantitative polymerase chain reaction. Independent variables were current depressive (30-item Inventory of Depressive Symptoms - Self Report) and anxiety (21-item Beck's Anxiety Inventory) symptoms and presence of a depressive or anxiety disorder diagnosis based on DSM-IV; mediator variables included physiological stress systems, metabolic syndrome components and lifestyle factors. Short LTL was associated with higher symptom severity (B = -2.4, p = 0.002) and current psychiatric diagnosis (B = -63.3, p = 0.024). C-reactive protein, interleukin-6, waist circumference, triglycerides, high-density lipoprotein cholesterol and cigarette smoking were significant mediators in the relationship between psychopathology and LTL. When all significant mediators were included in one model, the effect sizes of the relationships between LTL and symptom severity and current diagnosis were reduced by 36.7 and 32.7%, respectively, and the remaining direct effects were no longer significant. Pro-inflammatory cytokines, metabolic alterations and cigarette smoking are important mediators of the association between depressive and anxiety disorders and LTL. This calls for future research on intervention programs that take into account lifestyle changes in mental health care settings.

Operational workforce planning for check-in counters at airports

DEFF Research Database (Denmark)

Stolletz, Raik

2010-01-01

This paper addresses operation models for workforce planning for check-in systems at airports. We characterize different tasks of the hierarchical workforce planning problem with time-dependent demand. A binary linear programming formulation is developed for the fortnightly tour scheduling problem...

31 CFR 248.6 - Recovery of original check.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Recovery of original check. 248.6... § 248.6 Recovery of original check. (a) If the claimant recovers an original check after he has... or agency concerned regarding the negotiability of such original check. (b) In the event the...

CMM Interim Check (U)

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.

Environmental Reality Check.

Science.gov (United States)

Manicone, Santo

2001-01-01

Discusses the importance of educational facilities conducting "reality check" self-audits to uncover the real truth behind underlying environmental problems. An environmental compliance multimedia checklist is included. (GR)

7 CFR 1944.540 - Requesting TSA checks.

Science.gov (United States)

2010-01-01

... 7 Agriculture 13 2010-01-01 2009-01-01 true Requesting TSA checks. 1944.540 Section 1944.540... TSA checks. (a) The initial TSA check may cover the applicant's needs for the first calendar month. If... the next whole month. (b) The initial advance of TSA grant funds may not be requested simultaneously...

40 CFR 86.328-79 - Leak checks.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Leak checks. 86.328-79 Section 86.328... Gasoline-Fueled and Diesel-Fueled Heavy-Duty Engines; Gaseous Exhaust Test Procedures § 86.328-79 Leak checks. (a) Vacuum side leak check. (1) Any location within the analysis system where a vacuum leak could...

Methodology for Check Valve Selection to Maintain the Integrity of Pipeline against the Check Valve Slam for the KIJANG Research Reactor

Energy Technology Data Exchange (ETDEWEB)

Kim, Dayong; Yoon, Hyungi; Seo, Kyoungwoo; Kim, Seonhoon [KAERI, Daejeon (Korea, Republic of)

2016-05-15

The check valve slam results in a water hammer and unexpected system pressure rise in the pipeline. Sometimes, the pressure rise by check valve slam in the pipeline exceeds the design pressure and then it causes the rupture of pipeline. Therefore, check valve slam significantly influences on the integrity of pipe. Especially, this it is most likely to occur by check valve installed in the discharge of pump when one pump trips among the two or more running in parallel pump system. This study focuses on the check valve selection to maintain the integrity of PCS pipeline against the check valve slam. If design head for KJRR PCS pipeline is higher than the sum of static head and 11 m, any type check valves can be installed at the discharge of pump. However, if design head for KJRR PCS pipeline is lower than the sum of static head and 11 m, installation of swing and ball check on the discharge of pump must be avoid to prevent the rupture of PCS pipeline.

Methodology for Check Valve Selection to Maintain the Integrity of Pipeline against the Check Valve Slam for the KIJANG Research Reactor

International Nuclear Information System (INIS)

Kim, Dayong; Yoon, Hyungi; Seo, Kyoungwoo; Kim, Seonhoon

2016-01-01

The check valve slam results in a water hammer and unexpected system pressure rise in the pipeline. Sometimes, the pressure rise by check valve slam in the pipeline exceeds the design pressure and then it causes the rupture of pipeline. Therefore, check valve slam significantly influences on the integrity of pipe. Especially, this it is most likely to occur by check valve installed in the discharge of pump when one pump trips among the two or more running in parallel pump system. This study focuses on the check valve selection to maintain the integrity of PCS pipeline against the check valve slam. If design head for KJRR PCS pipeline is higher than the sum of static head and 11 m, any type check valves can be installed at the discharge of pump. However, if design head for KJRR PCS pipeline is lower than the sum of static head and 11 m, installation of swing and ball check on the discharge of pump must be avoid to prevent the rupture of PCS pipeline

Incremental Integrity Checking: Limitations and Possibilities

DEFF Research Database (Denmark)

Christiansen, Henning; Martinenghi, Davide

2005-01-01

Integrity checking is an essential means for the preservation of the intended semantics of a deductive database. Incrementality is the only feasible approach to checking and can be obtained with respect to given update patterns by exploiting query optimization techniques. By reducing the problem...... to query containment, we show that no procedure exists that always returns the best incremental test (aka simplification of integrity constraints), and this according to any reasonable criterion measuring the checking effort. In spite of this theoretical limitation, we develop an effective procedure...

Childhood Conscientiousness and Leukocyte Telomere Length 40 Years Later in Adult Women--Preliminary Findings of a Prospective Association.

Directory of Open Access Journals (Sweden)

Grant W Edmonds

Full Text Available Leukocyte telomere length (LTL shortens with age, and is a prospective marker of mortality related to cardiovascular disease. Many health behaviors and social environmental factors have been found to be associated with LTL. Several of these are also associated with conscientiousness, a dispositional personality trait. Conscientiousness is a propensity to be planful, adhere to social norms, and inhibit pre-potent responses. Like LTL, conscientiousness is prospectively related to mortality, possibly through cumulative effects on health over the life course via multiple pathways. As a result, we hypothesized that childhood levels of conscientiousness would predict LTL prospectively in adulthood. We selected a sample of 60 women in the Hawaii Personality and Health Cohort; 30 described by their teachers as high on conscientiousness in childhood and 30 described as low on the trait. Dried blood spot samples collected in adulthood 40 years later were used as sources of DNA for the LTL assay. Conscientiousness was associated with longer LTL (p = .02. Controlling for age did not account for this association. Controlling for education and physiological dysregulation partially attenuated the association, and the effect remained significant when accounting for differences in LTL across cultural groups. These results represent the first evidence that childhood personality prospectively predicts LTL 40 years later in adulthood. Our findings would be consistent with a mediation hypothesis whereby conscientiousness predicts life paths and trajectories of health that are reflected in rates of LTL erosion across the lifespan.

Swing check valve

International Nuclear Information System (INIS)

Eminger, H.E.

1977-01-01

A swing check valve which includes a valve body having an inlet and outlet is described. A recess in the valve body designed to hold a seal ring and a check valve disc swingable between open and closed positions. The disc is supported by a high strength wire secured at one end in a support spacer pinned through bearing blocks fixed to the valve body and at its other end in a groove formed on the outer peripheral surface of the disc. The parts are designed and chosen such to provide a lightweight valve disc which is held open by minimum velocity of fluid flowing through the valve which thus reduces oscillations and accompanying wear of bearings supporting the valve operating parts. (Auth.)

The effect of the severity of obstructive sleep apnea syndrome on telomere length.

Science.gov (United States)

Tempaku, Priscila Farias; Mazzotti, Diego Robles; Hirotsu, Camila; Andersen, Monica Levy; Xavier, Gabriela; Maurya, Pawan Kumar; Rizzo, Lucas Bortolotto; Brietzke, Elisa; Belangero, Sintia Iole; Bittencourt, Lia; Tufik, Sergio

2016-10-25

Aging is associated with an increase in the prevalence of obstructive sleep apnea syndrome (OSAS) as well as the shortening of telomeres. It is known that OSAS-related factors are stimuli that can contribute to the acceleration of cellular senescence. Thus, the present study aimed to compare the leukocyte telomere length (LTL) between OSAS patients and controls, as well as to verify the correlation between LTL and sleep parameters. We used DNA extracted of 928 individuals from EPISONO to measure the LTL by the quantitative real-time polymerase chain reaction. All individuals were subjected to one full-night polysomnography. LTL was significantly shorter in OSAS patients compared to controls. The results showed negative correlations between LTL and the following variables: apnea-hypopnea index, respiratory disturbance index, desaturation index and wake after sleep onset. LTL was positively correlated with sleep efficiency, total sleep time, basal, minimum and maximum oxygen saturation. Lastly, it was observed that OSAS severity was associated with shorter LTL even after adjusting for sex, age, years of schooling, body mass index, diabetes, stroke and heart attack. In conclusion, our study indicates the presence of an association between LTL and OSAS and a significant impact of severity of OSAS in telomeres shortening.

The heritability of leucocyte telomere length dynamics

DEFF Research Database (Denmark)

Hjelmborg, Jacob B; Dalgård, Christine; Möller, Sören

2015-01-01

variation among adults. A number of studies have estimated the heritability of LTL, but none has assessed the heritability of age-dependent LTL attrition. METHODS: We examined the heritability of LTL dynamics based on a longitudinal evaluation (an average follow-up of 12 years) in 355 monozygotic and 297...... dizygotic same-sex twins (aged 19-64 years at baseline). RESULTS: Heritability of LTL at baseline was estimated at 64% (95% CI 39% to 83%) with 22% (95% CI 6% to 49%) of shared environmental effects. Heritability of age-dependent LTL attrition rate was estimated at 28% (95% CI 16% to 44%). Individually...

Twin correlations of telomere length metrics

DEFF Research Database (Denmark)

Hjelmborg, Jacob B; Dalgård, Christine; Möller, Sören

2015-01-01

variation among adults. A number of studies have estimated the heritability of LTL, but none has assessed the heritability of age-dependent LTL attrition. METHODS: We examined the heritability of LTL dynamics based on a longitudinal evaluation (an average follow-up of 12 years) in 355 monozygotic and 297...... dizygotic same-sex twins (aged 19-64 years at baseline). RESULTS: Heritability of LTL at baseline was estimated at 64% (95% CI 39% to 83%) with 22% (95% CI 6% to 49%) of shared environmental effects. Heritability of age-dependent LTL attrition rate was estimated at 28% (95% CI 16% to 44%). Individually...

Stochastic Local Search for Core Membership Checking in Hedonic Games

Science.gov (United States)

Keinänen, Helena

Hedonic games have emerged as an important tool in economics and show promise as a useful formalism to model multi-agent coalition formation in AI as well as group formation in social networks. We consider a coNP-complete problem of core membership checking in hedonic coalition formation games. No previous algorithms to tackle the problem have been presented. In this work, we overcome this by developing two stochastic local search algorithms for core membership checking in hedonic games. We demonstrate the usefulness of the algorithms by showing experimentally that they find solutions efficiently, particularly for large agent societies.

Automatization and familiarity in repeated checking

NARCIS (Netherlands)

Dek, E.C.P.|info:eu-repo/dai/nl/313959552; van den Hout, M.A.|info:eu-repo/dai/nl/070445354; Giele, C.L.|info:eu-repo/dai/nl/318754460; Engelhard, I.M.|info:eu-repo/dai/nl/239681533

2015-01-01

Repetitive, compulsive-like checking of an object leads to reductions in memory confidence, vividness, and detail. Experimental research suggests that this is caused by increased familiarity with perceptual characteristics of the stimulus and automatization of the checking procedure (Dek, van den

40 CFR 86.163-00 - Spot check correlation procedures for vehicles tested using a simulation of the environmental...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Spot check correlation procedures for... Complete Heavy-Duty Vehicles; Test Procedures § 86.163-00 Spot check correlation procedures for vehicles... running change approval, each model year for any manufacturer undergoing the spot checking procedures of...

The dopamine D2/D3 receptor agonist quinpirole increases checking-like behaviour in an operant observing response task with uncertain reinforcement: a novel possible model of OCD.

Science.gov (United States)

Eagle, Dawn M; Noschang, Cristie; d'Angelo, Laure-Sophie Camilla; Noble, Christie A; Day, Jacob O; Dongelmans, Marie Louise; Theobald, David E; Mar, Adam C; Urcelay, Gonzalo P; Morein-Zamir, Sharon; Robbins, Trevor W

2014-05-01

Excessive checking is a common, debilitating symptom of obsessive-compulsive disorder (OCD). In an established rodent model of OCD checking behaviour, quinpirole (dopamine D2/3-receptor agonist) increased checking in open-field tests, indicating dopaminergic modulation of checking-like behaviours. We designed a novel operant paradigm for rats (observing response task (ORT)) to further examine cognitive processes underpinning checking behaviour and clarify how and why checking develops. We investigated i) how quinpirole increases checking, ii) dependence of these effects on D2/3 receptor function (following treatment with D2/3 receptor antagonist sulpiride) and iii) effects of reward uncertainty. In the ORT, rats pressed an 'observing' lever for information about the location of an 'active' lever that provided food reinforcement. High- and low-checkers (defined from baseline observing) received quinpirole (0.5mg/kg, 10 treatments) or vehicle. Parametric task manipulations assessed observing/checking under increasing task demands relating to reinforcement uncertainty (variable response requirement and active-lever location switching). Treatment with sulpiride further probed the pharmacological basis of long-term behavioural changes. Quinpirole selectively increased checking, both functional observing lever presses (OLPs) and non-functional extra OLPs (EOLPs). The increase in OLPs and EOLPs was long-lasting, without further quinpirole administration. Quinpirole did not affect the immediate ability to use information from checking. Vehicle and quinpirole-treated rats (VEH and QNP respectively) were selectively sensitive to different forms of uncertainty. Sulpiride reduced non-functional EOLPs in QNP rats but had no effect on functional OLPs. These data have implications for treatment of compulsive checking in OCD, particularly for serotonin-reuptake-inhibitor treatment-refractory cases, where supplementation with dopamine receptor antagonists may be beneficial

The dopamine D2/D3 receptor agonist quinpirole increases checking-like behaviour in an operant observing response task with uncertain reinforcement: A novel possible model of OCD?

Science.gov (United States)

Eagle, Dawn M.; Noschang, Cristie; d’Angelo, Laure-Sophie Camilla; Noble, Christie A.; Day, Jacob O.; Dongelmans, Marie Louise; Theobald, David E.; Mar, Adam C.; Urcelay, Gonzalo P.; Morein-Zamir, Sharon; Robbins, Trevor W.

2014-01-01

Excessive checking is a common, debilitating symptom of obsessive-compulsive disorder (OCD). In an established rodent model of OCD checking behaviour, quinpirole (dopamine D2/3-receptor agonist) increased checking in open-field tests, indicating dopaminergic modulation of checking-like behaviours. We designed a novel operant paradigm for rats (observing response task (ORT)) to further examine cognitive processes underpinning checking behaviour and clarify how and why checking develops. We investigated i) how quinpirole increases checking, ii) dependence of these effects on D2/3 receptor function (following treatment with D2/3 receptor antagonist sulpiride) and iii) effects of reward uncertainty. In the ORT, rats pressed an ‘observing’ lever for information about the location of an ‘active’ lever that provided food reinforcement. High- and low-checkers (defined from baseline observing) received quinpirole (0.5 mg/kg, 10 treatments) or vehicle. Parametric task manipulations assessed observing/checking under increasing task demands relating to reinforcement uncertainty (variable response requirement and active-lever location switching). Treatment with sulpiride further probed the pharmacological basis of long-term behavioural changes. Quinpirole selectively increased checking, both functional observing lever presses (OLPs) and non-functional extra OLPs (EOLPs). The increase in OLPs and EOLPs was long-lasting, without further quinpirole administration. Quinpirole did not affect the immediate ability to use information from checking. Vehicle and quinpirole-treated rats (VEH and QNP respectively) were selectively sensitive to different forms of uncertainty. Sulpiride reduced non-functional EOLPs in QNP rats but had no effect on functional OLPs. These data have implications for treatment of compulsive checking in OCD, particularly for serotonin-reuptake-inhibitor treatment-refractory cases, where supplementation with dopamine receptor antagonists may be

Improvement of seawater booster pump outlet check valve

International Nuclear Information System (INIS)

Li Xuning; Du Yansong; Huang Huimin

2010-01-01

Conventional island seawater booster pump set of QNPC 310 MWe unit are very important in the whole circulating cooling system, and the integrate function of seawater booster pump outlet check valve is the foundation of steady operation of the seawater booster pump set. The article mainly introduce that through the analyses to the reason to the problem that the seawater booster pump outlet check valve of QNPC 310 MWe unit appeared in past years by our team, and considering the influence of operation condition and circumstance, the team improve the seawater booster pump outlet check valve from swing check valve to shuttle check valve which operate more appropriately in the system. By the test of continuous practice, we make further modification to the inner structure of shuttle check valve contrapuntally, and therefore we solve the problem in seawater booster pump outlet check valve fundamentally which has troubled the security of system operation in past years, so we realize the aim of technical improvement and ensure that the system operate in safety and stability. (authors)

Diagnostic information in temporal compliance checking

NARCIS (Netherlands)

Ramezani Taghiabadi, E.; Fahland, D.; Dongen, van B.F.; Aalst, van der W.M.P.

2012-01-01

Compliance checking is gaining importance as today’s organizations need to show that operational processes are executed in a controlled manner while satisfying prede¿ned (legal) requirements. Deviations may be costly and expose the organization to severe risks. Compliance checking is of growing

31 CFR 245.8 - Receipt or recovery of original check.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Receipt or recovery of original check... CHECKS § 245.8 Receipt or recovery of original check. (a) If the original check is received or recovered... of instructions with respect to the negotiability of such check. (b) If the original check is...

Forgetting what you have checked: a link between working memory impairment and checking behaviors in obsessive-compulsive disorder.

Science.gov (United States)

Jaafari, N; Frasca, M; Rigalleau, F; Rachid, F; Gil, R; Olié, J-P; Guehl, D; Burbaud, P; Aouizerate, B; Rotgé, J-Y; Vibert, N

2013-02-01

Compulsive checking behaviors are common in obsessive-compulsive disorder (OCD). Several authors have suggested that these checking rituals could be related to memory deficits. Our aim was to test whether patients with OCD show working memory impairment in relation to their checking behavior. We evaluated the verbal and visuospatial components of patients' and controls' working memory using the reading span and backward location span tests. Checking behaviors were measured by recording participants' eye movements during an image comparison task using a non-invasive, infra-red TOBII 1750 eyetracker. Participants were seated, head-free, in a natural position in front of the eyetracker screen where the images were displayed. Patients with OCD made more gaze moves to compare images than controls. Both patients' working memory spans were reduced, and the patients' deficit in the comparison task was negatively related to their working memory spans. This work demonstrates that checking behavior in OCD is linked to a general reduction of the patients' verbal and visuospatial working memory span. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

38 CFR 21.4505 - Check delivery.

Science.gov (United States)

2010-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Check delivery. 21.4505...) VOCATIONAL REHABILITATION AND EDUCATION Education Loans § 21.4505 Check delivery. (a) General. Education... surviving spouse is enrolled for delivery by the educational institution. (b) Delivery and certification. (1...

Genome-wide association identifies OBFC1 as a locus involved in human leukocyte telomere biology.

Science.gov (United States)

Levy, Daniel; Neuhausen, Susan L; Hunt, Steven C; Kimura, Masayuki; Hwang, Shih-Jen; Chen, Wei; Bis, Joshua C; Fitzpatrick, Annette L; Smith, Erin; Johnson, Andrew D; Gardner, Jeffrey P; Srinivasan, Sathanur R; Schork, Nicholas; Rotter, Jerome I; Herbig, Utz; Psaty, Bruce M; Sastrasinh, Malinee; Murray, Sarah S; Vasan, Ramachandran S; Province, Michael A; Glazer, Nicole L; Lu, Xiaobin; Cao, Xiaojian; Kronmal, Richard; Mangino, Massimo; Soranzo, Nicole; Spector, Tim D; Berenson, Gerald S; Aviv, Abraham

2010-05-18

Telomeres are engaged in a host of cellular functions, and their length is regulated by multiple genes. Telomere shortening, in the course of somatic cell replication, ultimately leads to replicative senescence. In humans, rare mutations in genes that regulate telomere length have been identified in monogenic diseases such as dyskeratosis congenita and idiopathic pulmonary fibrosis, which are associated with shortened leukocyte telomere length (LTL) and increased risk for aplastic anemia. Shortened LTL is observed in a host of aging-related complex genetic diseases and is associated with diminished survival in the elderly. We report results of a genome-wide association study of LTL in a consortium of four observational studies (n = 3,417 participants with LTL and genome-wide genotyping). SNPs in the regions of the oligonucleotide/oligosaccharide-binding folds containing one gene (OBFC1; rs4387287; P = 3.9 x 10(-9)) and chemokine (C-X-C motif) receptor 4 gene (CXCR4; rs4452212; P = 2.9 x 10(-8)) were associated with LTL at a genome-wide significance level (P a gene associated with LTL (P = 1.1 x 10(-5)). The identification of OBFC1 through genome-wide association as a locus for interindividual variation in LTL in the general population advances the understanding of telomere biology in humans and may provide insights into aging-related disorders linked to altered LTL dynamics.

check cif.pdf

Indian Academy of Sciences (India)

AMMIN

Calculated. Reported. Volume ... PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density .... 3.24 Report ... checkCIF was carefully designed to identify outliers and unusual parameters, but every test has its limitations and alerts ...

Accuracy Test of Software Architecture Compliance Checking Tools : Test Instruction

NARCIS (Netherlands)

Prof.dr. S. Brinkkemper; Dr. Leo Pruijt; C. Köppe; J.M.E.M. van der Werf

2015-01-01

Author supplied: "Abstract Software Architecture Compliance Checking (SACC) is an approach to verify conformance of implemented program code to high-level models of architectural design. Static SACC focuses on the modular software architecture and on the existence of rule violating dependencies

46 CFR 10.214 - Security Check.

Science.gov (United States)

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Security Check. 10.214 Section 10.214 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN MERCHANT MARINER CREDENTIAL General Requirements for All Merchant Mariner Credentials § 10.214 Security Check. Until April 15, 2009...

[Effect of sucralfate on cytokines in rat with paraquat poisoning].

Science.gov (United States)

Zhu, Junbo; Yu, Yongtao; Li, Hongbo; Zheng, Fenshuang; Lin, Ruyun; Yang, Chun'ai

2018-03-01

To explore the effect of sucralfate on cytokines in rats with paraquat (PQ) poisoning. Seventy-two healthy male Sprague-Dawley (SD) rats were randomly divided into PQ model group, sodium bicarbonate intervention group (SB group) and sucralfate suspension gel group (LTL group), with 24 rats in each group. The rat model of PQ poisoning was reproduced by one-time intragastric administration of PQ solution 25 mg/kg. The rats in SB group and LTL group were intragastricly administrated with 5 mL×kg -1 ×d -1 of 100 g/L sodium bicarbonate or 200 g/L sucralfate at 2 hours after exposing to PQ, and the rats in PQ model group were given the same amount of sterile saline. The abdominal aortic blood of rats was collected at 1, 3, 6, and 10 days after PQ poisoning, and the levels of serum tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10) and transforming growth factor-β1 (TGF-β1) were determined by enzyme-linked immunosorbent assay (ELISA). The left lung tissue was harvested, and lung wet/dry weight (W/D) ratio was assessed. With prolonged exposure, lung W/D ratios in all the groups were increased gradually, reached the peak at 10 days, but in the SB group and LTL group, the amplitude of increase was obviously reduced, the ratios were significantly decreased at 6 days and 10 days as compared with those in PQ model group (SB group vs. PQ model group: 4.99±0.79 vs. 6.98±0.86 at 6 days, 5.61±0.36 vs. 7.36±0.95 at 10 days; LTL group vs. PQ model group: 4.61±0.24 vs. 6.98±0.86 at 6 days, 4.24±0.20 vs. 7.36±0.95 at 10 days, all P 0.05). After PQ poisoning, the levels of TNF-α, IL-10 and TGF-β1 were elevated, and reached the peak at 3 days and then decreased gradually. Compared with the PQ model group, serum TNF-α, IL-10 and TGF-β1 levels in SB group and LTL group were decreased significantly [SB group vs. PQ model group: 3-day TNF-α (ng/L) was 147.6±12.3 vs. 168.2±11.3, 3-day IL-10 (ng/L) was 65.4±3.2 vs. 115.1±9.2, 3-day TGF-β1 (ng/L) was 356.3±50.3 vs

7 CFR 58.243 - Checking quality.

Science.gov (United States)

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Checking quality. 58.243 Section 58.243 Agriculture... Procedures § 58.243 Checking quality. All milk, milk products and dry milk products shall be subject to inspection and analysis by the dairy plant for quality and condition throughout each processing operation...

Mothers' use of and attitudes to BabyCheck.

OpenAIRE

Thomson, Hilary; Ross, Sue; Wilson, Philip; McConnachie, Alex; Watson, Richard

2002-01-01

A copy of BabyCheck was sent to 497 mothers shortly after the birth of their baby. Six months later they were sent a questionnaire asking about their use of and attitudes to, BabyCheck. Questionnaires were returned by 323 (65%) mothers; 215 (67%) of them reported reading BabyCheck, the majority found it easy to understand (74%) and agreed with the advice (67%). Eighty-four (26%) of the mothers who returned the questionnaires reported using BabyCheck when their baby was ill; of these, 71% agre...

CMM Interim Check Design of Experiments (U)

Energy Technology Data Exchange (ETDEWEB)

Montano, Joshua Daniel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2015-07-29

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 and include a weekly interim check to reduce risk. The CMM interim check makes use of Renishaw’s Machine Checking Gauge which is an off-the-shelf product simulates a large sphere within a CMM’s measurement volume and allows for error estimation. As verification on the interim check process a design of experiments investigation was proposed to test a couple of key factors (location and inspector). The results from the two-factor factorial experiment proved that location influenced results more than the inspector or interaction.

How checking breeds doubt: reduced performance in a simple working memory task.

Science.gov (United States)

Harkin, Ben; Kessler, Klaus

2009-06-01

A paradox of memory research is that repeated checking results in a decrease in memory certainty, memory vividness and confidence [van den Hout, M. A., & Kindt, M. (2003a). Phenomenological validity of an OCD-memory model and the remember/know distinction. Behaviour Research and Therapy, 41, 369-378; van den Hout, M. A., & Kindt, M. (2003b). Repeated checking causes memory distrust. Behaviour Research and Therapy, 41, 301-316]. Although these findings have been mainly attributed to changes in episodic long-term memory, it has been suggested [Shimamura, A. P. (2000). Toward a cognitive neuroscience of metacognition. Consciousness and Cognition, 9, 313-323] that representations in working memory could already suffer from detrimental checking. In two experiments we set out to test this hypothesis by employing a delayed-match-to-sample working memory task. Letters had to be remembered in their correct locations, a task that was designed to engage the episodic short-term buffer of working memory [Baddeley, A. D. (2000). The episodic buffer: a new component in working memory? Trends in Cognitive Sciences, 4, 417-423]. Of most importance, we introduced an intermediate distractor question that was prone to induce frustrating and unnecessary checking on trials where no correct answer was possible. Reaction times and confidence ratings on the actual memory test of these trials confirmed the success of this manipulation. Most importantly, high checkers [cf. VOCI; Thordarson, D. S., Radomsky, A. S., Rachman, S., Shafran, R, Sawchuk, C. N., & Hakstian, A. R. (2004). The Vancouver obsessional compulsive inventory (VOCI). Behaviour Research and Therapy, 42(11), 1289-1314] were less accurate than low checkers when frustrating checking was induced, especially if the experimental context actually emphasized the irrelevance of the misleading question. The clinical relevance of this result was substantiated by means of an extreme groups comparison across the two studies. The findings

Remote versus face-to-face check-ups for asthma.

Science.gov (United States)

Kew, Kayleigh M; Cates, Christopher J

2016-04-18

Asthma remains a significant cause of avoidable morbidity and mortality. Regular check-ups with a healthcare professional are essential to monitor symptoms and adjust medication.Health services worldwide are considering telephone and internet technologies as a way to manage the rising number of people with asthma and other long-term health conditions. This may serve to improve health and reduce the burden on emergency and inpatient services. Remote check-ups may represent an unobtrusive and efficient way of maintaining contact with patients, but it is uncertain whether conducting check-ups in this way is effective or whether it may have unexpected negative consequences. To assess the safety and efficacy of conducting asthma check-ups remotely versus usual face-to-face consultations. We identified trials from the Cochrane Airways Review Group Specialised Register (CAGR) up to 24 November 2015. We also searched www.clinicaltrials.gov, the World Health Organization (WHO) trials portal, reference lists of other reviews and contacted trial authors for additional information. We included parallel randomised controlled trials (RCTs) of adults or children with asthma that compared remote check-ups conducted using any form of technology versus standard face-to-face consultations. We excluded studies that used automated telehealth interventions that did not include personalised contact with a health professional. We included studies reported as full-text articles, as abstracts only and unpublished data. Two review authors screened the literature search results and independently extracted risk of bias and numerical data. We resolved any disagreements by consensus, and we contacted study authors for missing information.We analysed dichotomous data as odds ratios (ORs) using study participants as the unit of analysis, and continuous data as mean differences using the random-effects models. We rated all outcomes using the Grading of Recommendations Assessment, Development and

7 CFR 1421.11 - Spot checks.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false Spot checks. 1421.11 Section 1421.11 Agriculture... ASSISTANCE LOANS AND LOAN DEFICIENCY PAYMENTS FOR 2008 THROUGH 2012 General § 1421.11 Spot checks. (a) CCC... CCC access to the farm and storage facility as necessary to conduct collateral inspections, or “spot...

32 CFR 635.6 - Name checks.

Science.gov (United States)

2010-07-01

... 32 National Defense 4 2010-07-01 2010-07-01 true Name checks. 635.6 Section 635.6 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS LAW ENFORCEMENT REPORTING Records Administration § 635.6 Name checks. (a) Information contained in military police records may be...

45 CFR 201.70 - Treatment of replacement checks.

Science.gov (United States)

2010-10-01

... 45 Public Welfare 2 2010-10-01 2010-10-01 false Treatment of replacement checks. 201.70 Section... STATES FOR PUBLIC ASSISTANCE PROGRAMS Review and Audits § 201.70 Treatment of replacement checks. (a... (FFP) for replacement checks under titles I, VI-A, X, XIV, XVI (AABD) except under the circumstances...

Participation in preventive health check-ups among 19,351 women in Germany

Directory of Open Access Journals (Sweden)

Stefanie Schülein

2017-06-01

Full Text Available In Germany, a biennial preventive health check-up has been available for individuals aged 35 and older since 1989. The check-up includes identification of cardiovascular disease risk factors and examinations for diabetes mellitus type 2 and kidney disease. Participation in preventive health check-ups among 19,351 women aged 35 to 74 in Germany in 2004 was investigated. Logistic regression was performed to examine associations between participation and age, marital status, education, socio-economic status (SES and region of residence. In total, 53.4% of women attended at least every two years, 23.4% attended irregularly and 23.2% never attended. In adjusted models, single, divorced, separated or widowed women were less likely to have a preventive health check-up at least every two years compared to married women (OR 0.63, 95% CI 0.57–0.71, while women in eastern Germany were less likely to participate (OR 0.80, 95% CI 0.75–0.86 than women in western Germany. Education showed no association with having a preventive health check-up at least every two years; however, women with low SES were less likely to participate compared to those with high SES (OR 0.82, 95% CI 0.74–0.92. About half of eligible women reported participating in health check-ups at least every two years, with participation varying according to socio-demographic characteristics. Women who are less likely to participate may benefit from receiving invitation letters within the framework of an organised programme. The benefits of general health checks, however, need to be evaluated.

Recent improvements in check valve monitoring methods

International Nuclear Information System (INIS)

Haynes, H.D.

1991-01-01

In support of the NRC Nuclear Plant Aging Research (NPAR) program, ORNL has carried out an evaluation of three check valve monitoring methods: acoustic emission, ultrasonic inspection, and magnetic flux signature analysis (MFSA). This work has focussed on determining the capabilities of each method to provide diagnostic information useful in determining check valve aging and service wear effects (degradation) and undesirable operating modes. In addition, as part of the ORNL Advanced Diagnostic Engineering Research and Development Center (ADEC), two novel nonintrusive monitoring methods were developed (external ac- and dc-magnetic monitoring) that provide several improvements over the other methods. None of the examined methods could, by themselves, monitor the instantaneous position and motion of check valve internals and valve leakage; however, the combination of acoustic emission monitoring with one of the other methods provides the means to determine vital check valve operational information. This paper describes the benefits and limitations associated with each method and includes recent laboratory and field test data to illustrate the capabilities of these methods to detect simulated check valve degradation. 3 refs., 22 figs., 4 tabs

Recent improvements in check valve monitoring methods

International Nuclear Information System (INIS)

Haynes, H.D.

1990-01-01

In support of the NRC Nuclear Plant Aging Research (NPAR) program, ORNL has carried out an evaluation of three check valve monitoring methods: acoustic emission, ultrasonic inspection, and magnetic flux signature analysis (MFSA). This work has focused on determining the capabilities of each method to provide diagnostic information useful in determining check valve aging and service wear effects (degradation) and undesirable operating modes. In addition, as part of the ORNL Advanced Diagnostic Engineering Research and Development Center (ADEC), two noval nonintrusive monitoring methods were developed (external ac- and dc-magnetic monitoring) that provide several improvements over the other methods. None of the examined methods could, by themselves, monitor the instantaneous position and motion of check valve internals and valve leakage; however, the combination of acoustic emission monitoring with one of the other methods provides the means to determine vital check valve operational information. This paper describes the benefits and limitations associated with each method and includes recent laboratory and field test data to illustrate the capabilities of these methods to detect simulated check valve degradation. 3 refs., 22 figs., 4 tabs

Parity-Check Network Coding for Multiple Access Relay Channel in Wireless Sensor Cooperative Communications

Directory of Open Access Journals (Sweden)

Du Bing

2010-01-01

Full Text Available A recently developed theory suggests that network coding is a generalization of source coding and channel coding and thus yields a significant performance improvement in terms of throughput and spatial diversity. This paper proposes a cooperative design of a parity-check network coding scheme in the context of a two-source multiple access relay channel (MARC model, a common compact model in hierarchical wireless sensor networks (WSNs. The scheme uses Low-Density Parity-Check (LDPC as the surrogate to build up a layered structure which encapsulates the multiple constituent LDPC codes in the source and relay nodes. Specifically, the relay node decodes the messages from two sources, which are used to generate extra parity-check bits by a random network coding procedure to fill up the rate gap between Source-Relay and Source-Destination transmissions. Then, we derived the key algebraic relationships among multidimensional LDPC constituent codes as one of the constraints for code profile optimization. These extra check bits are sent to the destination to realize a cooperative diversity as well as to approach MARC decode-and-forward (DF capacity.

Checking the new IRI model: The bottomside B parameters

International Nuclear Information System (INIS)

Mosert, M.; Buresova, D.; Miro, G.; Lazo, B.; Ezquer, R.

2003-01-01

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. (author)

Checking the new IRI model The bottomside B parameters

CERN Document Server

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.

Check valve diagnostics utilizing acoustic and magnetic technologies

International Nuclear Information System (INIS)

Agostinelli, A.

1991-01-01

The potential hazards associated with check valve failures make it necessary to detect check valve problems before they cause significant damage. In the nuclear industry, check valve failures are known to have resulted in damaging water hammer conditions, overpressurization of low pressure systems, steam binding of auxiliary feedwater pumps, and other serious component damage in power plant environments. Similar problems exist in fossil power and various process industries, but the resources dedicated to valve maintenance issues are greatly reduced. However, the trend toward plant life extension, predictive maintenance, and maximum operating efficiency will raise the general awareness of check valve maintenance in commercial (non-nuclear) applications. Although this paper includes specific references to the nuclear industry, the check valve problem conditions and diagnostic techniques apply across all power and process plant environments. The ability to accurately diagnose check valve conditions using non-intrusive, predictive maintenance testing methods allows for a more cost-efficient, productive maintenance program. One particular diagnostic system, called Quickcheck trademark, assists utilities in addressing these concerns. This article presents actual field test data and analysis that demonstrate the power of check valve diagnostics. Prior to presenting the field data, a brief overview of the system is overviewed

Framework for Grading of Cyber Security Check-List upon I and C Architecture

International Nuclear Information System (INIS)

Shin, Jin Soo; Heo, Gyunyong; Son, Han Seong

2016-01-01

Cyber-attack can threaten research reactors as well as NPPs since the goal of cyber-attack is not only to make a catastrophic accident such as radiation exposure against public health but also to make chaos or anxiety among the public. Moreover, there is more probability to occur in research reactors than NPPs since research reactors has more users than NPPs. The nuclear regulatory agencies such as U.S.NRC and KINAC (Korea Institute of Nuclear Nonproliferation and Control) have published regulatory guides for rules against cyber-attack to maintain cyber security of nuclear facilities. U.S.NRC has published a regulatory guide (U.S.NRC / RG-5.71) and KINAC has developed a regulatory standard (KINAC / RS-015) to establish a cyber security for nuclear facilities. However, these regulatory documents represent check-list for cyber security regardless of reactor type such as NPPs or research reactors. The proposed framework in this paper was grading of cyber security check-lists with BBN by I and C architecture such as NPPs and research reactors. First, the BBN model was developed to apply I and C system architecture of target nuclear facility. The architecture model calculates the cyber security risk with structural architecture, vulnerability, and mitigation measure. Second, cyber security check-lists are defined in cyber security documents. It is, then, used with the consideration of mitigation measures of BBN model in order to apply architectural characteristic. Third, after assuming cyber-attack occurs to I and C system, the model calculates the posterior information using Bayesian update. Finally, the cyber security check-lists for nuclear facilities are graded upon I and C architecture with the posterior information for mitigation measures

Framework for Grading of Cyber Security Check-List upon I and C Architecture

Energy Technology Data Exchange (ETDEWEB)

Shin, Jin Soo; Heo, Gyunyong [Kyunghee University, Yongin (Korea, Republic of); Son, Han Seong [Joongbu University, Geumsan (Korea, Republic of)

2016-05-15

Cyber-attack can threaten research reactors as well as NPPs since the goal of cyber-attack is not only to make a catastrophic accident such as radiation exposure against public health but also to make chaos or anxiety among the public. Moreover, there is more probability to occur in research reactors than NPPs since research reactors has more users than NPPs. The nuclear regulatory agencies such as U.S.NRC and KINAC (Korea Institute of Nuclear Nonproliferation and Control) have published regulatory guides for rules against cyber-attack to maintain cyber security of nuclear facilities. U.S.NRC has published a regulatory guide (U.S.NRC / RG-5.71) and KINAC has developed a regulatory standard (KINAC / RS-015) to establish a cyber security for nuclear facilities. However, these regulatory documents represent check-list for cyber security regardless of reactor type such as NPPs or research reactors. The proposed framework in this paper was grading of cyber security check-lists with BBN by I and C architecture such as NPPs and research reactors. First, the BBN model was developed to apply I and C system architecture of target nuclear facility. The architecture model calculates the cyber security risk with structural architecture, vulnerability, and mitigation measure. Second, cyber security check-lists are defined in cyber security documents. It is, then, used with the consideration of mitigation measures of BBN model in order to apply architectural characteristic. Third, after assuming cyber-attack occurs to I and C system, the model calculates the posterior information using Bayesian update. Finally, the cyber security check-lists for nuclear facilities are graded upon I and C architecture with the posterior information for mitigation measures.

Model-Checking an Alternating-time Temporal Logic with Knowledge, Imperfect Information, Perfect Recall and Communicating Coalitions

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.

First experiences with the LHC BLM sanity checks

Science.gov (United States)

Emery, J.; Dehning, B.; Effinger, E.; Nordt, A.; Sapinski, M. G.; Zamantzas, C.

2010-12-01

The reliability concerns have driven the design of the Large Hardron Collider (LHC) Beam Loss Monitoring (BLM) system from the early stage of the studies up to the present commissioning and the latest development of diagnostic tools. To protect the system against non-conformities, new ways of automatic checking have been developed and implemented. These checks are regularly and systematically executed by the LHC operation team to ensure that the system status is after each test "as good as new". The sanity checks are part of this strategy. They are testing the electrical part of the detectors (ionisation chamber or secondary emission detector), their cable connections to the front-end electronics, further connections to the back-end electronics and their ability to request a beam abort. During the installation and in the early commissioning phase, these checks have shown their ability to find also non-conformities caused by unexpected failure event scenarios. In every day operation, a non-conformity discovered by this check inhibits any further injections into the LHC until the check confirms the absence of non-conformities.

First experiences with the LHC BLM sanity checks

International Nuclear Information System (INIS)

Emery, J; Dehning, B; Effinger, E; Nordt, A; Sapinski, M G; Zamantzas, C

2010-01-01

The reliability concerns have driven the design of the Large Hardron Collider (LHC) Beam Loss Monitoring (BLM) system from the early stage of the studies up to the present commissioning and the latest development of diagnostic tools. To protect the system against non-conformities, new ways of automatic checking have been developed and implemented. These checks are regularly and systematically executed by the LHC operation team to ensure that the system status is after each test a s good as new . The sanity checks are part of this strategy. They are testing the electrical part of the detectors (ionisation chamber or secondary emission detector), their cable connections to the front-end electronics, further connections to the back-end electronics and their ability to request a beam abort. During the installation and in the early commissioning phase, these checks have shown their ability to find also non-conformities caused by unexpected failure event scenarios. In every day operation, a non-conformity discovered by this check inhibits any further injections into the LHC until the check confirms the absence of non-conformities.

First experiences with the LHC BLM sanity checks

Energy Technology Data Exchange (ETDEWEB)

Emery, J; Dehning, B; Effinger, E; Nordt, A; Sapinski, M G; Zamantzas, C, E-mail: Jonathan.emery@cern.ch [CERN, CH-1211 Geneve 23 (Switzerland)

2010-12-15

The reliability concerns have driven the design of the Large Hardron Collider (LHC) Beam Loss Monitoring (BLM) system from the early stage of the studies up to the present commissioning and the latest development of diagnostic tools. To protect the system against non-conformities, new ways of automatic checking have been developed and implemented. These checks are regularly and systematically executed by the LHC operation team to ensure that the system status is after each test {sup a}s good as new{sup .} The sanity checks are part of this strategy. They are testing the electrical part of the detectors (ionisation chamber or secondary emission detector), their cable connections to the front-end electronics, further connections to the back-end electronics and their ability to request a beam abort. During the installation and in the early commissioning phase, these checks have shown their ability to find also non-conformities caused by unexpected failure event scenarios. In every day operation, a non-conformity discovered by this check inhibits any further injections into the LHC until the check confirms the absence of non-conformities.

Optimization analysis of swing check valve closing induced water hammer

International Nuclear Information System (INIS)

Han Wenwei; Han Weishi; Guo Qing; Wang Xin; Liu Chunyu

2014-01-01

A mathematical-physics model of double pump parallel feed system was constructed. The water hammer was precisely calculated, which was formed in the closing process of swing check valve. And a systematic analysis was carried out to determine the influence of the torques from both valve plate and damping torsion spring on the valve closing induced water hammer. The results show that the swing check valve would distinctly produce the water hammer during the closing procedure in the double pump parallel feed water system. The torques of the valve plate can partly reduce the water hammer effect, and implying appropriate materials of valve plate and appropriate spring can effectively relieve the harm of water hammer. (authors)

Synthesizing Dynamic Programming Algorithms from Linear Temporal Logic Formulae

Science.gov (United States)

Rosu, Grigore; Havelund, Klaus

2001-01-01

The problem of testing a linear temporal logic (LTL) formula on a finite execution trace of events, generated by an executing program, occurs naturally in runtime analysis of software. We present an algorithm which takes an LTL formula and generates an efficient dynamic programming algorithm. The generated algorithm tests whether the LTL formula is satisfied by a finite trace of events given as input. The generated algorithm runs in linear time, its constant depending on the size of the LTL formula. The memory needed is constant, also depending on the size of the formula.

An experimental method to verify soil conservation by check dams on the Loess Plateau, China.

Science.gov (United States)

Xu, X Z; Zhang, H W; Wang, G Q; Chen, S C; Dang, W Q

2009-12-01

A successful experiment with a physical model requires necessary conditions of similarity. This study presents an experimental method with a semi-scale physical model. The model is used to monitor and verify soil conservation by check dams in a small watershed on the Loess Plateau of China. During experiments, the model-prototype ratio of geomorphic variables was kept constant under each rainfall event. Consequently, experimental data are available for verification of soil erosion processes in the field and for predicting soil loss in a model watershed with check dams. Thus, it can predict the amount of soil loss in a catchment. This study also mentions four criteria: similarities of watershed geometry, grain size and bare land, Froude number (Fr) for rainfall event, and soil erosion in downscaled models. The efficacy of the proposed method was confirmed using these criteria in two different downscaled model experiments. The B-Model, a large scale model, simulates watershed prototype. The two small scale models, D(a) and D(b), have different erosion rates, but are the same size. These two models simulate hydraulic processes in the B-Model. Experiment results show that while soil loss in the small scale models was converted by multiplying the soil loss scale number, it was very close to that of the B-Model. Obviously, with a semi-scale physical model, experiments are available to verify and predict soil loss in a small watershed area with check dam system on the Loess Plateau, China.

Checking and Balancing: Banking and Budgeting.

Science.gov (United States)

Thypin, Marilyn; Glasner, Lynne

A short fictional work for limited English speakers is presented that relates a young couple's experience in learning about managing their money more carefully by budgeting and maintaining a checking account. Since the couple did not have a checking account, they had to go to their savings bank in order to pay each bill and they had to keep cash…

Glovebox pressure relief and check valve

Energy Technology Data Exchange (ETDEWEB)

Blaedel, K.L.

1986-03-17

This device is a combined pressure relief valve and check valve providing overpressure protection and preventing back flow into an inert atmosphere enclosure. The pressure relief is embodied by a submerged vent line in a mercury reservior, the releif pressure being a function of the submerged depth. The pressure relief can be vented into an exhaust system and the relieving pressure is only slightly influenced by the varying pressure in the exhaust system. The check valve is embodied by a ball which floats on the mercury column and contacts a seat whenever vacuum exists within the glovebox enclosure. Alternatively, the check valve is embodied by a vertical column of mercury, the maximum back pressure being a function of the height of the column of mercury.

Glovebox pressure relief and check valve

International Nuclear Information System (INIS)

Blaedel, K.L.

1986-01-01

This device is a combined pressure relief valve and check valve providing overpressure protection and preventing back flow into an inert atmosphere enclosure. The pressure relief is embodied by a submerged vent line in a mercury reservior, the releif pressure being a function of the submerged depth. The pressure relief can be vented into an exhaust system and the relieving pressure is only slightly influenced by the varying pressure in the exhaust system. The check valve is embodied by a ball which floats on the mercury column and contacts a seat whenever vacuum exists within the glovebox enclosure. Alternatively, the check valve is embodied by a vertical column of mercury, the maximum back pressure being a function of the height of the column of mercury

Photogrammetric approach to automated checking of DTMs

DEFF Research Database (Denmark)

Potucková, Marketa

2005-01-01

Geometrically accurate digital terrain models (DTMs) are essential for orthoimage production and many other applications. Collecting reference data or visual inspection are reliable but time consuming and therefore expensive methods for finding errors in DTMs. In this paper, a photogrammetric...... approach to automated checking and improving of DTMs is evaluated. Corresponding points in two overlapping orthoimages are found by means of area based matching. Provided the image orientation is correct, discovered displacements correspond to DTM errors. Improvements of the method regarding its...

Check valve slam caused by air intrusion in emergency cooling water system

International Nuclear Information System (INIS)

Martin, C.S.

2011-01-01

Waterhammer pressures were experienced during periodic starting of Residual Heat Removal (RHR) pumps at a nuclear plant. Prior to an analytical investigation careful analysis performed by plant engineers indicated that the spring effect of entrapped air in a heat exchanger resulted in water hammer due to check valve slam following flow reversal. In order to determine in more detail the values of pertinent parameters controlling this water hammer a hydraulic transient analysis was performed of the RHR piping system, including essential elements such as the pump, check valve, and heat exchanger. Using characteristic torque and pressure loss curves the motion of the check valve was determined. By comparing output of the water hammer analysis with site recordings of pump discharge pressure the computer model was calibrated, allowing for a realistic estimate of the quantity of entrapped air in the heat exchanger. (author)

Repeated checking induces uncertainty about future threat

NARCIS (Netherlands)

Giele, C.L.|info:eu-repo/dai/nl/318754460; Engelhard, I.M.|info:eu-repo/dai/nl/239681533; van den Hout, M.A.|info:eu-repo/dai/nl/070445354; Dek, E.C.P.|info:eu-repo/dai/nl/313959552; Damstra, Marianne; Douma, Ellen

2015-01-01

Studies have shown that obsessive-compulsive (OC) -like repeated checking paradoxically increases memory uncertainty. This study tested if checking also induces uncertainty about future threat by impairing the distinction between danger and safety cues. Participants (n = 54) engaged in a simulated

A Proof-checked Verification of a Real-Time Communication Protocol

NARCIS (Netherlands)

Polak, I.

We present an analysis of a protocol developed by Philips to connect several components of an audio-system. The verification of the protocol is carried out using the timed I/O-automata model of Lynch and Vaandrager. The verification has been partially proof-checked with the interactive proof

Inkjet 3D printed check microvalve

International Nuclear Information System (INIS)

Walczak, Rafał; Adamski, Krzysztof; Lizanets, Danylo

2017-01-01

3D printing enables fast and relatively easy fabrication of various microfluidic structures including microvalves. A check microvalve is the simplest valve enabling control of the fluid flow in microchannels. Proper operation of the check valve is ensured by a movable element that tightens the valve seat during backward flow and enables free flow for forward pressure. Thus, knowledge of the mechanical properties of the movable element is crucial for optimal design and operation of the valve. In this paper, we present for the first time the results of investigations on basic mechanical properties of the building material used in multijet 3D printing. Specified mechanical properties were used in the design and fabrication of two types of check microvalve—with deflecting or hinge-fixed microflap—with 200 µ m and 300 µ m thickness. Results of numerical simulation and experimental data of the microflap deflection were obtained and compared. The valves were successfully 3D printed and characterised. Opening/closing characteristics of the microvalve for forward and backward pressures were determined. Thus, proper operation of the check microvalve so developed was confirmed. (technical note)

SWAT Check: A Screening Tool to Assist Users in the Identification of Potential Model Application Problems.

Science.gov (United States)

White, Michael J; Harmel, R Daren; Arnold, Jeff G; Williams, Jimmy R

2014-01-01

The Soil and Water Assessment Tool (SWAT) is a basin-scale hydrologic model developed by the United States Department of Agriculture Agricultural Research Service. SWAT's broad applicability, user-friendly model interfaces, and automatic calibration software have led to a rapid increase in the number of new users. These advancements also allow less experienced users to conduct SWAT modeling applications. In particular, the use of automated calibration software may produce simulated values that appear appropriate because they adequately mimic measured data used in calibration and validation. Autocalibrated model applications (and often those of unexperienced modelers) may contain input data errors and inappropriate parameter adjustments not readily identified by users or the autocalibration software. The objective of this research was to develop a program to assist users in the identification of potential model application problems. The resulting "SWAT Check" is a stand-alone Microsoft Windows program that (i) reads selected SWAT output and alerts users of values outside the typical range; (ii) creates process-based figures for visualization of the appropriateness of output values, including important outputs that are commonly ignored; and (iii) detects and alerts users of common model application errors. By alerting users to potential model application problems, this software should assist the SWAT community in developing more reliable modeling applications. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Developing Formal Correctness Properties from Natural Language Requirements

Science.gov (United States)

Nikora, Allen P.

2006-01-01

This viewgraph presentation reviews the rationale of the program to transform natural language specifications into formal notation.Specifically, automate generation of Linear Temporal Logic (LTL)correctness properties from natural language temporal specifications. There are several reasons for this approach (1) Model-based techniques becoming more widely accepted, (2) Analytical verification techniques (e.g., model checking, theorem proving) significantly more effective at detecting types of specification design errors (e.g., race conditions, deadlock) than manual inspection, (3) Many requirements still written in natural language, which results in a high learning curve for specification languages, associated tools and increased schedule and budget pressure on projects reduce training opportunities for engineers, and (4) Formulation of correctness properties for system models can be a difficult problem. This has relevance to NASA in that it would simplify development of formal correctness properties, lead to more widespread use of model-based specification, design techniques, assist in earlier identification of defects and reduce residual defect content for space mission software systems. The presentation also discusses: potential applications, accomplishments and/or technological transfer potential and the next steps.

Systematic Review of the Check-In, Check-Out Intervention for Students at Risk for Emotional and Behavioral Disorders

Science.gov (United States)

Hawken, Leanne S.; Bundock, Kaitlin; Kladis, Kristin; O'Keeffe, Breda; Barret, Courtenay A.

2014-01-01

The purpose of this systematic literature review was to summarize outcomes of the Check-in Check-out (CICO) intervention across elementary and secondary settings. Twenty-eight studies utilizing both single subject and group (experimental and quasi-experimental) designs were included in this review. Median effect sizes across the eight group…

Principle and opening-closing character analysis of DC check valve

International Nuclear Information System (INIS)

Han Xu; Zhou Yu

2006-01-01

When the behaviour of main pump in PWR power plant change, as a result of arresting fluid countercurrent current by check valve, water hammer phenomena met occur more or less in loop. Serious water hammer not only met brought incident of over pressure, imperil pressure boundary, but also may engender check valve lapse. DC check valve is a kind of new theory check valve, is designed to avoid serious water hammer phenomena at tradition check valve closing, the analyses and experiment indicate that DC check valve can availably solve water hammer problem in the loop, and be able to reliably prevent fluid countercurrent. (authors)

Heritability of telomere length in a study of long-lived families

DEFF Research Database (Denmark)

Honig, Lawrence S; Kang, Min Suk; Cheng, Rong

2015-01-01

in a given age group, it has been hypothesized to be a marker of biological aging. However, the principal basis for the variation of human LTL has not been established, although various studies have reported heritability. Here, we use a family-based study of longevity to study heritability of LTL in 3037...... individuals. We show that LTL is shorter in older individuals, and in males, and has a high heritability (overall h(2) = 0.54). In the offspring generation, who are in middle-life, we find an ordinal relationship: persons more-closely-related to elderly probands have longer LTL than persons less...

The use of check valve performance data to support new concepts (probabilistic risk assessment, condition monitoring) for check valve program

Energy Technology Data Exchange (ETDEWEB)

Hart, K.A.; Gower, D.

1996-12-01

The concept of developing an integrated check valve database based on the Nuclear Power Reliability Data System (NPRDS) data was presented at the last Symposium. The Nuclear Industry Check Valve Group (NIC), working in cooperation with the Oak Ridge National Laboratory (ORNL), has completed an operational database of check valve performance from 1984 to the present. NIC has committed to the nuclear industry to periodically update the data and maintain this information accessible. As the new concepts of probabilistic risk analysis and condition monitoring are integrated into the American Society of Mechanical Engineers (ASME) Code, a critical element will be performance data. From check valve performance data, feasible failure modes and rates can be established. When a failure rate or frequency of failures can be established based on a significant enough population (sampling), a more solid foundation for focusing resources and determining appropriate frequencies and testing can be determined. The presentation will give the updated status of the NIC Check Valve Performance Database covering (1) methodology used to combine the original ORNL data; (2) process/controls established for continuing update and refinement of the data; (3) discussion of how this data is being utilized by (a) OM-22 for condition monitoring, and (b) risk-based inservice testing work of Westinghouse Owners` Group; and (4) results/trends of data evaluations. At the 1994 Symposium, ORNL provided an update as of 1991 to their original work of 1984 -1990 which they had performed to characterize check valve degradations and failures in the nuclear industry. These characterizations will be updated to 1995 and additional reviews provided to give insight into the current condition and trends of check valve performance.

The use of check valve performance data to support new concepts (probabilistic risk assessment, condition monitoring) for check valve program

International Nuclear Information System (INIS)

Hart, K.A.; Gower, D.

1996-01-01

The concept of developing an integrated check valve database based on the Nuclear Power Reliability Data System (NPRDS) data was presented at the last Symposium. The Nuclear Industry Check Valve Group (NIC), working in cooperation with the Oak Ridge National Laboratory (ORNL), has completed an operational database of check valve performance from 1984 to the present. NIC has committed to the nuclear industry to periodically update the data and maintain this information accessible. As the new concepts of probabilistic risk analysis and condition monitoring are integrated into the American Society of Mechanical Engineers (ASME) Code, a critical element will be performance data. From check valve performance data, feasible failure modes and rates can be established. When a failure rate or frequency of failures can be established based on a significant enough population (sampling), a more solid foundation for focusing resources and determining appropriate frequencies and testing can be determined. The presentation will give the updated status of the NIC Check Valve Performance Database covering (1) methodology used to combine the original ORNL data; (2) process/controls established for continuing update and refinement of the data; (3) discussion of how this data is being utilized by (a) OM-22 for condition monitoring, and (b) risk-based inservice testing work of Westinghouse Owners' Group; and (4) results/trends of data evaluations. At the 1994 Symposium, ORNL provided an update as of 1991 to their original work of 1984 -1990 which they had performed to characterize check valve degradations and failures in the nuclear industry. These characterizations will be updated to 1995 and additional reviews provided to give insight into the current condition and trends of check valve performance

Accuracy Test of Software Architecture Compliance Checking Tools – Test Instruction

NARCIS (Netherlands)

Pruijt, Leo; van der Werf, J.M.E.M.|info:eu-repo/dai/nl/36950674X; Brinkkemper., Sjaak|info:eu-repo/dai/nl/07500707X

2015-01-01

Software Architecture Compliance Checking (SACC) is an approach to verify conformance of implemented program code to high-level models of architectural design. Static SACC focuses on the modular software architecture and on the existence of rule violating dependencies between modules. Accurate tool

40 CFR 89.317 - NOX converter check.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false NOX converter check. 89.317 Section 89.317 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED..., the chemiluminescent oxides of nitrogen analyzer shall be checked for NO2 to NO converter efficiency...

Immediate Effects of Body Checking Behaviour on Negative and Positive Emotions in Women with Eating Disorders: An Ecological Momentary Assessment Approach.

Science.gov (United States)

Kraus, Nicole; Lindenberg, Julia; Zeeck, Almut; Kosfelder, Joachim; Vocks, Silja

2015-09-01

Cognitive-behavioural models of eating disorders state that body checking arises in response to negative emotions in order to reduce the aversive emotional state and is therefore negatively reinforced. This study empirically tests this assumption. For a seven-day period, women with eating disorders (n = 26) and healthy controls (n = 29) were provided with a handheld computer for assessing occurring body checking strategies as well as negative and positive emotions. Serving as control condition, randomized computer-emitted acoustic signals prompted reports on body checking and emotions. There was no difference in the intensity of negative emotions before body checking and in control situations across groups. However, from pre- to post-body checking, an increase in negative emotions was found. This effect was more pronounced in women with eating disorders compared with healthy controls. Results are contradictory to the assumptions of the cognitive-behavioural model, as body checking does not seem to reduce negative emotions. Copyright © 2015 John Wiley & Sons, Ltd and Eating Disorders Association.

Modelling and analysis of a compensator burst after a check valve slam with the pressure surge code DYVRO mod. 3

International Nuclear Information System (INIS)

Neuhaus, Thorsten; Schaffrath, Andreas

2009-01-01

In this contribution the analysis and calculation of a compensator burst after a pump start and check valve slam with the pressure surge code DYVRO mod. 3 are presented. The compensator burst occurred in the essential service water system (ESWS) of a pressurized water reactor (PWR) in a deviant operation mode. Due to lack of knowledge about the causes a systematic investigation has been performed by TUV NORD SysTec GmbH and Co. KG. The following scenario was identified as most likely: Because of maintenance a heat exchanger was shut off from the ESWS by a closed valve. Due to the hydrostatic pressure profile air had been sucked in through this leaky closed valve forming an air bubble. After the pump start the water was accelerated against the closed valve where the air bubble was compressed. The subsequent backflow resulted in a fast closing of a check valve and a pressure surge that caused the compensator burst. Calculations have been performed with the self developed and validated pressure surge computer code DYVRO mod. 3. The present paper is focussed on the modelling of the pipe system, the pump, the check valve and the behaviour of the air bubble as well as the simulation of the incident. The calculated maximum pressure in the ESWS is above 3 MPa, which is approx. four times higher than the design pressure of 0.7 MPa. This pressure increase has led most likely to the abrupt compensator failure. (author)

AUTOMATED HOTEL CHECK-IN SERTA DAMPAKNYA PADA TENAGA KERJA LOKAL

Directory of Open Access Journals (Sweden)

Ni Gusti Nyoman Suci Murni

2017-10-01

Full Text Available The tourism sector is one of the most heavily influenced sectors of information technology. Hotels that are a component of tourism cannot be separated from these influences, especially in information services, room reservations, check-in / check-out service, and other services. With the sophistication of information technology, everyone can access any information, from anywhere; at a very cheap price even every country provides free facilities for that purpose. This study uses qualitative methods where the data source obtained by looking for some libraries related to self check-in. The results show that there are some differences that applied between the check-in manual and self check-in, and the impact caused by the application of self check-in. The positive impact of self check-in are speeding up the check-in process, saving payrolls, simplifying services, simplifying reporting, and saving time. While the negative impacts such as reducing employment in developing countries, reducing social communication / human touch, reducing the understanding of cross cultural understanding, allowing the occurrence of crime (cyber crime as well as very expensive initial cost.

Diagnosis checking of statistical analysis in RCTs indexed in PubMed.

Science.gov (United States)

Lee, Paul H; Tse, Andy C Y

2017-11-01

Statistical analysis is essential for reporting of the results of randomized controlled trials (RCTs), as well as evaluating their effectiveness. However, the validity of a statistical analysis also depends on whether the assumptions of that analysis are valid. To review all RCTs published in journals indexed in PubMed during December 2014 to provide a complete picture of how RCTs handle assumptions of statistical analysis. We reviewed all RCTs published in December 2014 that appeared in journals indexed in PubMed using the Cochrane highly sensitive search strategy. The 2014 impact factors of the journals were used as proxies for their quality. The type of statistical analysis used and whether the assumptions of the analysis were tested were reviewed. In total, 451 papers were included. Of the 278 papers that reported a crude analysis for the primary outcomes, 31 (27·2%) reported whether the outcome was normally distributed. Of the 172 papers that reported an adjusted analysis for the primary outcomes, diagnosis checking was rarely conducted, with only 20%, 8·6% and 7% checked for generalized linear model, Cox proportional hazard model and multilevel model, respectively. Study characteristics (study type, drug trial, funding sources, journal type and endorsement of CONSORT guidelines) were not associated with the reporting of diagnosis checking. The diagnosis of statistical analyses in RCTs published in PubMed-indexed journals was usually absent. Journals should provide guidelines about the reporting of a diagnosis of assumptions. © 2017 Stichting European Society for Clinical Investigation Journal Foundation.

SPEED ROLLER STAND MEASUREMENT SYSTEM CHECKING TECHNIQUE

Directory of Open Access Journals (Sweden)

Y. Zybtsev

2011-01-01

Full Text Available The study has shown that the accuracy of brakes checking by inertial stands depends upon the applied methods of measurement of braking parameters (stand slowing down, braking distance, brakes triggering time, current speed as well as the methods of metrological checking of measuring system canals.

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...

Relative Leukocyte Telomere Length, Hematological Parameters and Anemia - Data from the Berlin Aging Study II (BASE-II).

Science.gov (United States)

Meyer, Antje; Salewsky, Bastian; Buchmann, Nikolaus; Steinhagen-Thiessen, Elisabeth; Demuth, Ilja

2016-01-01

The length of the chromosome ends, telomeres, is widely accepted as a biomarker of aging. However, the dynamic of the relationship between telomere length and hematopoietic parameters in the normal aging process, which is of particular interest with respect to age-related anemia, is not well understood. We have analyzed the relationship between relative leukocyte telomere length (rLTL) and several hematological parameters in the older group of the Berlin Aging Study II (BASE-II) participants. This paper also compares rLTL between both BASE-II age groups (22-37 and 60-83 years). Genomic DNA was extracted from peripheral blood leukocytes of BASE-II participants and used to determine rLTL by a quantitative PCR protocol. Standard methods were used to determine blood parameters, and the WHO criteria were used to identify anemic participants. Telomere length data were available for 444 younger participants (28.4 ± 3.1 years old; 52% women) and 1,460 older participants (68.2 ± 3.7 years old; 49.4% women). rLTL was significantly shorter in BASE-II participants of the older group (p = 3.7 × 10-12) and in women (p = 4.2 × 10-31). rLTL of older men exhibited a statistically significant, positive partial correlation with mean corpuscular hemoglobin (MCH; p = 0.012) and MCH concentration (p = 0.002). While these correlations were only observed in men, the rLTL of older women was negatively correlated with the number of thrombocytes (p = 0.015) in the same type of analysis. Among all older participants, 6% met the criteria to be categorized as 'anemic'; however, there was no association between anemia and rLTL. In the present study, we have detected isolated correlations between rLTL and hematological parameters; however, in all cases, rLTL explained only a small part of the variation of the analyzed parameters. In disagreement with some other studies showing similar data, we interpret the association between rLTL and some of the hematological parameters studied here to be

Restructuring of workflows to minimise errors via stochastic model checking: An automated evolutionary approach

International Nuclear Information System (INIS)

Herbert, L.T.; Hansen, Z.N.L.

2016-01-01

This paper presents a framework for the automated restructuring of stochastic workflows to reduce the impact of faults. The framework allows for the modelling of workflows by means of a formalised subset of the BPMN workflow language. We extend this modelling formalism to describe faults and incorporate an intention preserving stochastic semantics able to model both probabilistic- and non-deterministic behaviour. Stochastic model checking techniques are employed to generate the state-space of a given workflow. Possible improvements obtained by restructuring are measured by employing the framework's capacity for tracking real-valued quantities associated with states and transitions of the workflow. The space of possible restructurings of a workflow is explored by means of an evolutionary algorithm, where the goals for improvement are defined in terms of optimising quantities, typically employed to model resources, associated with a workflow. The approach is fully automated and only the modelling of the production workflows, potential faults and the expression of the goals require manual input. We present the design of a software tool implementing this framework and explore the practical utility of this approach through an industrial case study in which the risk of production failures and their impact are reduced by restructuring the workflow. - Highlights: • We present a framework which allows for the automated restructuring of workflows. • This framework seeks to minimise the impact of errors on the workflow. • We illustrate a scalable software implementation of this framework. • We explore the practical utility of this approach through an industry case. • The impact of errors can be substantially reduced by restructuring the workflow.

NRC valve performance test program - check valve testing

International Nuclear Information System (INIS)

Jeanmougin, N.M.

1987-01-01

The Valve Performance Test Program addresses the current requirements for testing of pressure isolation valves (PIVs) in light water reactors. Leak rate monitoring is the current method used by operating commercial power plants to survey the condition of their PIVs. ETEC testing of three check valves (4-inch, 6-inch, and 12-inch nominal diameters) indicates that leak rate testing is not a reliable method for detecting impending valve failure. Acoustic emission monitoring of check valves shows promise as a method of detecting loosened internals damage. Future efforts will focus on evaluation of acoustic emission monitoring as a technique for determining check valve condition. Three gate valves also will be tested to evaluate whether the check valve results are applicable to gate type PIVs

Microscopic analysis and simulation of check-mark stain on the galvanized steel strip

Science.gov (United States)

So, Hongyun; Yoon, Hyun Gi; Chung, Myung Kyoon

2010-11-01

When galvanized steel strip is produced through a continuous hot-dip galvanizing process, the thickness of adhered zinc film is controlled by plane impinging air gas jet referred to as "air-knife system". In such a gas-jet wiping process, stain of check-mark or sag line shape frequently appears. The check-mark defect is caused by non-uniform zinc coating and the oblique patterns such as "W", "V" or "X" on the coated surface. The present paper presents a cause and analysis of the check-mark formation and a numerical simulation of sag lines by using the numerical data produced by Large Eddy Simulation (LES) of the three-dimensional compressible turbulent flow field around the air-knife system. It was found that there is alternating plane-wise vortices near the impinging stagnation region and such alternating vortices move almost periodically to the right and to the left sides on the stagnation line due to the jet flow instability. Meanwhile, in order to simulate the check-mark formation, a novel perturbation model has been developed to predict the variation of coating thickness along the transverse direction. Finally, the three-dimensional zinc coating surface was obtained by the present perturbation model. It was found that the sag line formation is determined by the combination of the instantaneous coating thickness distribution along the transverse direction near the stagnation line and the feed speed of the steel strip.

12 CFR 229.36 - Presentment and issuance of checks.

Science.gov (United States)

2010-01-01

... Section 229.36 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM AVAILABILITY OF FUNDS AND COLLECTION OF CHECKS (REGULATION CC) Collection of Checks § 229... on the check, whether in magnetic ink or in fractional form; (3) At any branch or head office, if the...

FIZCON, ENDF/B Cross-Sections Redundancy Check

International Nuclear Information System (INIS)

Dunford, Charles L.

2007-01-01

1 - Description of program or function: FIZCON is a program for checking that an evaluated data file has valid data and conforms to recommended procedures. Version 7.01 (April 2005): set success flag after return from beginning; fixed valid level check for an isomer; fixed subsection energy range test in ckf9; changed lower limit on potential scattering test; fixed error in j-value test when l=0 and i=0; added one more significant figure to union grid check and sum up output messages; partial fission cross sections mt=19,20,21 and 38 did not require secondary energy distributions in file 5; corrected product test for elastic scattering; moved potential scattering test to psyche. Version 7.02 (May 2005): Fixed resonance parameter sum test. 2 - Method of solution: FIZCON can recognise the difference between ENDF-6 and ENDF-5 formats and performs its tests accordingly. Some of the tests performed include: data arrays are in increasing energy order; resonance parameter widths add up to the total; Q-values are reasonable and consistent; no required sections are missing and all cover the proper energy range; secondary distributions are normalized to 1.0; energy conservation in decay spectra. Optional tests can be performed to check the redundant cross sections, and algorithms can be used to check for possible incorrect entry of data values (Deviant Point test)

[Memory Checking Tests].

Science.gov (United States)

Hart, Joseph T.

Two basic tests for checking memory skills are included in these appendices. The first, the General Information Test, uses the same 150 items for each of its two versions. One version is a completion-type test which measures recall by requiring the examinee to supply a specific response. The other version supplements each of the 150 items with…

Check Sample Abstracts.

Science.gov (United States)

Alter, David; Grenache, David G; Bosler, David S; Karcher, Raymond E; Nichols, James; Rajadhyaksha, Aparna; Camelo-Piragua, Sandra; Rauch, Carol; Huddleston, Brent J; Frank, Elizabeth L; Sluss, Patrick M; Lewandrowski, Kent; Eichhorn, John H; Hall, Janet E; Rahman, Saud S; McPherson, Richard A; Kiechle, Frederick L; Hammett-Stabler, Catherine; Pierce, Kristin A; Kloehn, Erica A; Thomas, Patricia A; Walts, Ann E; Madan, Rashna; Schlesinger, Kathie; Nawgiri, Ranjana; Bhutani, Manoop; Kanber, Yonca; Abati, Andrea; Atkins, Kristen A; Farrar, Robert; Gopez, Evelyn Valencerina; Jhala, Darshana; Griffin, Sonya; Jhala, Khushboo; Jhala, Nirag; Bentz, Joel S; Emerson, Lyska; Chadwick, Barbara E; Barroeta, Julieta E; Baloch, Zubair W; Collins, Brian T; Middleton, Owen L; Davis, Gregory G; Haden-Pinneri, Kathryn; Chu, Albert Y; Keylock, Joren B; Ramoso, Robert; Thoene, Cynthia A; Stewart, Donna; Pierce, Arand; Barry, Michelle; Aljinovic, Nika; Gardner, David L; Barry, Michelle; Shields, Lisa B E; Arnold, Jack; Stewart, Donna; Martin, Erica L; Rakow, Rex J; Paddock, Christopher; Zaki, Sherif R; Prahlow, Joseph A; Stewart, Donna; Shields, Lisa B E; Rolf, Cristin M; Falzon, Andrew L; Hudacki, Rachel; Mazzella, Fermina M; Bethel, Melissa; Zarrin-Khameh, Neda; Gresik, M Vicky; Gill, Ryan; Karlon, William; Etzell, Joan; Deftos, Michael; Karlon, William J; Etzell, Joan E; Wang, Endi; Lu, Chuanyi M; Manion, Elizabeth; Rosenthal, Nancy; Wang, Endi; Lu, Chuanyi M; Tang, Patrick; Petric, Martin; Schade, Andrew E; Hall, Geraldine S; Oethinger, Margret; Hall, Geraldine; Picton, Avis R; Hoang, Linda; Imperial, Miguel Ranoa; Kibsey, Pamela; Waites, Ken; Duffy, Lynn; Hall, Geraldine S; Salangsang, Jo-Anne M; Bravo, Lulette Tricia C; Oethinger, Margaret D; Veras, Emanuela; Silva, Elvia; Vicens, Jimena; Silva, Elvio; Keylock, Joren; Hempel, James; Rushing, Elizabeth; Posligua, Lorena E; Deavers, Michael T; Nash, Jason W; Basturk, Olca; Perle, Mary Ann; Greco, Alba; Lee, Peng; Maru, Dipen; Weydert, Jamie Allen; Stevens, Todd M; Brownlee, Noel A; Kemper, April E; Williams, H James; Oliverio, Brock J; Al-Agha, Osama M; Eskue, Kyle L; Newlands, Shawn D; Eltorky, Mahmoud A; Puri, Puja K; Royer, Michael C; Rush, Walter L; Tavora, Fabio; Galvin, Jeffrey R; Franks, Teri J; Carter, James Elliot; Kahn, Andrea Graciela; Lozada Muñoz, Luis R; Houghton, Dan; Land, Kevin J; Nester, Theresa; Gildea, Jacob; Lefkowitz, Jerry; Lacount, Rachel A; Thompson, Hannis W; Refaai, Majed A; Quillen, Karen; Lopez, Ana Ortega; Goldfinger, Dennis; Muram, Talia; Thompson, Hannis

2009-02-01

The following abstracts are compiled from Check Sample exercises published in 2008. These peer-reviewed case studies assist laboratory professionals with continuing medical education and are developed in the areas of clinical chemistry, cytopathology, forensic pathology, hematology, microbiology, surgical pathology, and transfusion medicine. Abstracts for all exercises published in the program will appear annually in AJCP.

Mandatory Identification Bar Checks: How Bouncers Are Doing Their Job

Science.gov (United States)

Monk-Turner, Elizabeth; Allen, John; Casten, John; Cowling, Catherine; Gray, Charles; Guhr, David; Hoofnagle, Kara; Huffman, Jessica; Mina, Moises; Moore, Brian

2011-01-01

The behavior of bouncers at on site establishments that served alcohol was observed. Our aim was to better understand how bouncers went about their job when the bar had a mandatory policy to check identification of all customers. Utilizing an ethnographic decision model, we found that bouncers were significantly more likely to card customers that…

Multiple measures of adiposity are associated with mean leukocyte telomere length in the northern Finland birth cohort 1966.

Directory of Open Access Journals (Sweden)

Jessica L Buxton

Full Text Available Studies of leukocyte telomere length (LTL and adiposity have produced conflicting results, and the relationship between body mass index (BMI and telomere length throughout life remains unclear. We therefore tested association of adult LTL measured in 5,598 participants with: i childhood growth measures (BMI and age at adiposity rebound (AR; ii change in BMI from childhood to adulthood and iii adult BMI, waist-to-hip ratio (WHR, body adiposity index (BAI. Childhood BMI at AR was positively associated with LTL at 31 years in women (P = 0.041. Adult BMI and WHR in both men (P = 0.025 and P = 0.049, respectively and women (P = 0.029 and P = 0.008, respectively, and BAI in women (P = 0.021 were inversely associated with LTL at 31 years. An increase in standardised BMI between early childhood and adulthood was associated with shorter adult LTL in women (P = 0.008. We show that LTL is inversely associated with multiple measures of adiposity in both men and women. Additionally, BMI increase in women from childhood to adulthood is associated with shorter telomeres at age 31, potentially indicating accelerated biological ageing.

A performance benchmark over semantic rule checking approaches in construction industry

NARCIS (Netherlands)

Pauwels, P.; de Farias, T.; Zhang, C.; Roxin, A.; Beetz, J.; De Roo, J.; Nicolle, C.

2017-01-01

As more and more architectural design and construction data is represented using the Resource Description Framework (RDF) data model, it makes sense to take advantage of the logical basis of RDF and implement a semantic rule checking process as it is currently not available in the architectural

A short leucocyte telomere length is associated with development of insulin resistance

DEFF Research Database (Denmark)

Verhulst, Simon; Dalgård, Christine; Labat, Carlos

2016-01-01

AIMS/HYPOTHESIS: A number of studies have shown that leucocyte telomere length (LTL) is inversely associated with insulin resistance and type 2 diabetes mellitus. The aim of the present longitudinal cohort study, utilising a twin design, was to assess whether shorter LTL predicts insulin resistance...... and insulin resistance over an average of 12 years were performed in a subset of the Registry consisting of 338 (184 monozygotic and 154 dizygotic) same-sex twin pairs. RESULTS: Age at baseline examination was 37.4 ± 9.6 (mean ± SD) years. Baseline insulin resistance was not associated with age......-dependent changes in LTL (attrition) over the follow-up period, whereas baseline LTL was associated with changes in insulin resistance during this period. The shorter the LTL at baseline, the more pronounced was the increase in insulin resistance over the follow-up period (p 

The criticality check and its applicability for nuclear material accounting

International Nuclear Information System (INIS)

Sanchez Espinoza, V.H.; Adam, E.; Knorr, J.

1988-01-01

Different procedures are used by the realization of nuclear material check by the IAEA. The criticality check belongs to these methods and it appropriates especially to verification of the nuclear material inventory of reactors. General aspects of the applicability of this check procedure are formulated and application criteria are deduced. By the example of solid-moderated homogeneous zero-power reactors it is demonstrated the unsecurity which is to be reckoned by applying the criticality check. Finally a possibility for the reduction of errors in core material determination by additional measuring methods without questioning the criticality check method is presented. (author)

Calibration and check light source

Energy Technology Data Exchange (ETDEWEB)

Nejedla, B; Krotil, J

1979-02-15

The light source is designed for calibrating photomultipliers and checking the function of the thermoluminescent dosemeters evaluation equipment. The check light source consists of a polymer material-based (polyvinyl toluene) plastic scintillator and a 2-phenyl-5-(4-bisphenyl)-1,3,4-oxadiazol and/or paraterphenyl activator, and of emission spectrum shifters for response in the green and the blue light regions. The plastic scintillator is sealed in a case to whose bottom a radiation source is fixed, such as a /sup 90/Sr-/sup 90/Y source of an activity of 1.85x10/sup 3/s/sup -1/ to 0.74x10/sup 9/s/sup -1/.

26 CFR 301.6657-1 - Bad checks.

Science.gov (United States)

2010-04-01

... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Bad checks. 301.6657-1 Section 301.6657-1... Additions to the Tax and Additional Amounts § 301.6657-1 Bad checks. (a) In general. Except as provided in... district director that it was tendered in good faith with reasonable cause to believe that it would be duly...

Vertical pump with free floating check valve

International Nuclear Information System (INIS)

Lindsay, M.

1980-01-01

A vertical pump is described which has a bottom discharge with a free floating check valve disposed in the outlet plenum thereof. The free floating check valve comprises a spherical member with a hemispherical cage-like member attached thereto which is capable of allowing forward or reverse flow under appropriate conditions while preventing reverse flow under inappropriate conditions

Prenatal exposure to perfluoroalkyl and polyfluoroalkyl substances affects leukocyte telomere length in female newborns.

Science.gov (United States)

Liu, Han; Chen, Qian; Lei, Lei; Zhou, Wei; Huang, Lisu; Zhang, Jun; Chen, Dan

2018-04-01

Evidence has shown that leukocyte telomere length (LTL) at birth is related to the susceptibility to various diseases in later life and the setting of newborn LTL is influenced by the intrauterine environment. Perfluoroalkyl and polyfluoroalkyl substances (PFASs), as a kind of persistent organic pollutants, are commonly used in commercial and domestic applications and are capable of crossing the maternal-fetal barrier during pregnancy. We hypothesized that intrauterine exposure to PFASs may affect fetal LTL by increasing oxidative stress. To verify this hypothesis, LTL, concentrations of PFASs and reactive oxygen species (ROS) were measured in umbilical cord blood of 581 newborns from a prospective cohort. Our results showed that there were interactions between PFOS/PFDA and sex on LTL and ROS. The LTL was significantly shorter (0.926 ± 0.053 vs 0.945 ± 0.054, P = .023 for PFOS; 0.919 ± 0.063 vs 0.940 ± 0.059, P = .011 for PFDA) and the ROS levels were extremely higher (252.9 ± 60.5 [M] vs 233.5 ± 53.6 [M], P = .031 for PFOS; 255.2 ± 62.9 [M] vs 232.9 ± 58.3 [M], P = .011 for PFDA) in the female newborns whose PFOS or PFDA concentrations fell in the upmost quartile compared with those in the lowest quartile after adjusting for potential confounders. ROS levels were inversely associated with LTL in female newborns (β = -1.42 × 10 -4 , P = .022). 13% of the effect of PFOS on female LTL was mediated through ROS approximately by the mediation analyses. However, in male newborns, no relationships among PFASs, ROS and LTL were observed. Our findings suggest a "programming" role of PFASs on fetal telomere biology system in females in intrauterine stage. Copyright © 2018 Elsevier Ltd. All rights reserved.

Checking Consistency of C and Verilog using Predicate Abstraction and Induction

National Research Council Canada - National Science Library

Clarke, Edmund; Kroening, Daniel

2004-01-01

.... In contrast to existing tools that perform predicate abstraction, our approach is SAT-based and allows all ANSI-C and Verilog operators in the predicates. We report experimental results on an out-of-order RISC processor. We compare the performance of the new technique to Bounded Model Checking (BMC).

STABILITAS CHECK DAM DI ARBORETUM DESA SUMBER BRANTAS

Directory of Open Access Journals (Sweden)

Endang Purwati

2012-09-01

Full Text Available Abstract: The stability of check-dam in arboretum of Sumber Brantas village. Sumber Brantas water sources area is arboretum territory which has to be maintained as conservation either for technical or vegetation (plants cover by sustainable development. Arboretum territory is made as asylum in irrigation system district of Brantas River. This research discusses technical conservation activity to build the check dam in conserving the area. Check dam is built dimensionally by using HEC-RAS Program to get safe and stable dimension for rolling, shifting and piping of Sf > 1.5, and based on hydrologic analysis to get maximum flood discharge of 48.01 m3second-1. Hydraulic analysis is used to get water level profile and pressure for the dam body. Stability of the structure will be controlled by construction load (weight of check dam and its fully sediment storage condition. The result of this research shows that the safe and stable dimension for check dam are as follows: 28 meter of width; 3 meter of main height; 1.5 meter of sub-height; 10 meter of stilling basin length (Main Dam–Sub Dam.

Secure open cloud in data transmission using reference pattern and identity with enhanced remote privacy checking

Science.gov (United States)

Vijay Singh, Ran; Agilandeeswari, L.

2017-11-01

To handle the large amount of client’s data in open cloud lots of security issues need to be address. Client’s privacy should not be known to other group members without data owner’s valid permission. Sometime clients are fended to have accessing with open cloud servers due to some restrictions. To overcome the security issues and these restrictions related to storing, data sharing in an inter domain network and privacy checking, we propose a model in this paper which is based on an identity based cryptography in data transmission and intermediate entity which have client’s reference with identity that will take control handling of data transmission in an open cloud environment and an extended remote privacy checking technique which will work at admin side. On behalf of data owner’s authority this proposed model will give best options to have secure cryptography in data transmission and remote privacy checking either as private or public or instructed. The hardness of Computational Diffie-Hellman assumption algorithm for key exchange makes this proposed model more secure than existing models which are being used for public cloud environment.

The impact of gender on the assessment of body checking behavior.

Science.gov (United States)

Alfano, Lauren; Hildebrandt, Tom; Bannon, Katie; Walker, Catherine; Walton, Kate E

2011-01-01

Body checking includes any behavior aimed at global or specific evaluations of appearance characteristics. Men and women are believed to express these behaviors differently, possibly reflecting different socialization. However, there has been no empirical test of the impact of gender on body checking. A total of 1024 male and female college students completed two measures of body checking, the Body Checking Questionnaire and the Male Body Checking Questionnaire. Using multiple group confirmatory factor analysis, differential item functioning (DIF) was explored in a composite of these measures. Two global latent factors were identified (female and male body checking severity), and there were expected gender differences in these factors even after controlling for DIF. Ten items were found to be unbiased by gender and provide a suitable brief measure of body checking for mixed gender research. Practical applications for body checking assessment and theoretical implications are discussed. Copyright © 2010 Elsevier Ltd. All rights reserved.

Compliance checking of data-aware and resource-aware compliance requirements

NARCIS (Netherlands)

Ramezani Taghiabadi, E.; Gromov, V.; Fahland, D.; Aalst, van der W.M.P.; Meersman, R.; Panetto, H.; Dillon, T.; Missikoff, M.; Liu, L.; Pastor, O.; Cuzzocrea, A.; Sllis, T.

2014-01-01

Compliance checking is gaining importance as today’s organizations need to show that their business practices are in accordance with predefined (legal) requirements. Current compliance checking techniques are mostly focused on checking the control-flow perspective of business processes. This paper

12 CFR Appendix C to Part 229 - Model Availability Policy Disclosures, Clauses, and Notices; Model Substitute Check Policy...

Science.gov (United States)

2010-01-01

...-case holds) C-19Notice at automated teller machines C-20Notice at automated teller machines (delayed... would like a list of the routing numbers for these institutions. C-9—Automated Teller Machine Deposits (Extended Hold) Deposits at Automated Teller Machines Funds from any deposits (cash or checks) made at...

UK Department of Environment Quality Checking Laboratory

International Nuclear Information System (INIS)

Burgoyne, K.E.; Green, T.H.; Maxwell, D.J.; Smith, D.L.G.

1990-01-01

The purpose of Taywood Engineering Ltd was to develop and evaluate techniques for the non-destructive and destructive examination of both low and intermediate level radioactive waste packages. The contract also included a study on the conceptual design and cost of a permanent Waste Quality Checking facility. The June 1986 contract was completed in November 1989. A second contract was awarded in September 1989 to extend the scope to include Quality Checking of hazardous waste and to increase the throughput of low level waste. This paper highlights the techniques developed during these programmes and applied to a range of real low level waste packages. The feasibility of operating a pilot scale facility for the independent Quality Checking of LLW has been successfully demonstrated. (orig.)

Cycle time reduction by Html report in mask checking flow

Science.gov (United States)

Chen, Jian-Cheng; Lu, Min-Ying; Fang, Xiang; Shen, Ming-Feng; Ma, Shou-Yuan; Yang, Chuen-Huei; Tsai, Joe; Lee, Rachel; Deng, Erwin; Lin, Ling-Chieh; Liao, Hung-Yueh; Tsai, Jenny; Bowhill, Amanda; Vu, Hien; Russell, Gordon

2017-07-01

The Mask Data Correctness Check (MDCC) is a reticle-level, multi-layer DRC-like check evolved from mask rule check (MRC). The MDCC uses extended job deck (EJB) to achieve mask composition and to perform a detailed check for positioning and integrity of each component of the reticle. Different design patterns on the mask will be mapped to different layers. Therefore, users may be able to review the whole reticle and check the interactions between different designs before the final mask pattern file is available. However, many types of MDCC check results, such as errors from overlapping patterns usually have very large and complex-shaped highlighted areas covering the boundary of the design. Users have to load the result OASIS file and overlap it to the original database that was assembled in MDCC process on a layout viewer, then search for the details of the check results. We introduce a quick result-reviewing method based on an html format report generated by Calibre® RVE. In the report generation process, we analyze and extract the essential part of result OASIS file to a result database (RDB) file by standard verification rule format (SVRF) commands. Calibre® RVE automatically loads the assembled reticle pattern and generates screen shots of these check results. All the processes are automatically triggered just after the MDCC process finishes. Users just have to open the html report to get the information they need: for example, check summary, captured images of results and their coordinates.

Context-aware compliance checking

NARCIS (Netherlands)

Werf, van der J.M.E.M.; Verbeek, H.M.W.; Aalst, van der W.M.P.; Barros, A.; Gal, A.; Kindler, E.

2012-01-01

Organizations face more and more the burden to show that their business is compliant with respect to many different boundaries. The activity of compliance checking is commonly referred to as auditing. As information systems supporting the organization’s business record their usage, process mining

Emotions and family interactions in childhood: Associations with leukocyte telomere length emotions, family interactions, and telomere length.

Science.gov (United States)

Robles, Theodore F; Carroll, Judith E; Bai, Sunhye; Reynolds, Bridget M; Esquivel, Stephanie; Repetti, Rena L

2016-01-01

Conceptualizations of links between stress and cellular aging in childhood suggest that accumulating stress predicts shorter leukocyte telomere length (LTL). At the same time, several models suggest that emotional reactivity to stressors may play a key role in predicting cellular aging. Using intensive repeated measures, we tested whether exposure or emotional "reactivity" to conflict and warmth in the family were related to LTL. Children (N=39; 30 target children and 9 siblings) between 8 and 13 years of age completed daily diary questionnaires for 56 consecutive days assessing daily warmth and conflict in the marital and the parent-child dyad, and daily positive and negative mood. To assess exposure to conflict and warmth, diary scale scores were averaged over the 56 days. Mood "reactivity" was operationalized by using multilevel modeling to generate estimates of the slope of warmth or conflict scores (marital and parent-child, separately) predicting same-day mood for each individual child. After diary collection, a blood sample was collected to determine LTL. Among children aged 8-13 years, a stronger association between negative mood and marital conflict, suggesting greater negative mood reactivity to marital conflict, was related to shorter LTL (B=-1.51, pfamily and marital conflict and warmth, and positive and negative mood over a two-month period. To our knowledge, these findings, although cross-sectional, represent the first evidence showing that link between children's affective responses and daily family interactions may have implications for telomere length. Copyright © 2015 Elsevier Ltd. All rights reserved.

Impact of alcohol checks and social norm on driving under the influence of alcohol (DUI).

Science.gov (United States)

Meesmann, Uta; Martensen, Heike; Dupont, Emmanuelle

2015-07-01

This study investigated the influence of alcohol checks and social norm on self-reported driving under the influence of alcohol above the legal limit (DUI). The analysis was based on the responses of 12,507 car drivers from 19 European countries to the SARTRE-4 survey (2010). The data were analysed by means of a multiple logistic regression-model on two levels: (1) individual and (2) national level. On the individual level the results revealed that driving under the influence (DUI) was positively associated with male gender, young age (17-34), personal experience with alcohol checks, the perceived likelihood of being checked for alcohol, perceived drunk driving behaviour of friends (social norm) and was negatively associated with higher age (55+). On a national level, the results showed a negative association with a lower legal alcohol limit (BAC 0.2g/l compared with BAC 0.5g/l) and the percentage of drivers checked for alcohol. DUI was positively associated with the percentage of respondents in the country that reported that their friends drink and drive (social norm). The comparison of the results obtained on national and individual levels shows a paradoxical effect of alcohol checks: Countries with more alcohol checks show lower DUI (negative association) but respondents who have been personally checked for alcohol show a higher chance of DUI (positive association). Possible explanations of this paradox are discussed. The effects of the social norm variable (perceived drunk driving behaviour of friends) are positively associated with DUI on both levels. Copyright © 2015 Elsevier Ltd. All rights reserved.

Get Your Kids Moving and Check Some Chores off Your List

Science.gov (United States)

... Check Recipe Certification Program Nutrition Requirements Heart-Check Professional Resources Contact the Heart-Check Certification Program Simple Cooking and Recipes Dining Out Choosing a Restaurant Deciphering ...

PSYCHE, ENDF/B Data Consistency Check in ENDF Format

International Nuclear Information System (INIS)

Dunford, Charles L.

2007-01-01

1 - Description of program or function: PSYCHE is a program for checking the physics content of an evaluated data file. It can recognise the difference between ENDF-5 or ENDF-6 formats and performs its tests accordingly. Version 7.01 (April 2005): set success flag after return from begin, added potential scattering test formerly in Fizcon. Version 7.02 (May 2005): Fixed bug in calculation of L=2 penetrability. 2 - Method of solution: PSYCHE checks for energy conservation for emitted neutrons and photons, checks Wick's limit for elastic scattering, analyses resonance parameter statistics, calculates thermal cross sections and resonance integrals, examines continuity across resonance region boundaries and checks 'Q' values against mass tables

Consistency Checking of Web Service Contracts

DEFF Research Database (Denmark)

Cambronero, M. Emilia; Okika, Joseph C.; Ravn, Anders Peter

2008-01-01

Behavioural properties are analyzed for web service contracts formulated in Business Process Execution Language (BPEL) and Choreography Description Language (CDL). The key result reported is an automated technique to check consistency between protocol aspects of the contracts. The contracts...... are abstracted to (timed) automata and from there a simulation is set up, which is checked using automated tools for analyzing networks of finite state processes. Here we use the Concurrency Work Bench. The proposed techniques are illustrated with a case study that include otherwise difficult to analyze fault...

A planar PDMS micropump using in-contact minimized-leakage check valves

International Nuclear Information System (INIS)

Ni, Junhui; Li, Beizhi; Huang, Fengliang; Wang, Bin; Lin, Qiao

2010-01-01

We present a micropump with a simple planar design featuring compliant in-contact check valves in a single layer, which allows for a simple structure and easy system integration. The micropump, based on poly(dimethylsiloxane) (PDMS), primarily consists of a pneumatically driven thin membrane, a pump chamber, and two in-plane check valves. The pair of check valves is based on an in-contact flap–stopper configuration and is able to minimize leakage flow, greatly enhancing the reliability and performance of the micropump. Systematic experimental characterization of the micropump has been performed in terms of the frequency response of the pumping flow rate with respect to factors including device geometry (e.g. chamber height) and operating parameters (e.g. pneumatic driving pressure and backpressure). The results demonstrate that this micropump is capable of reliably generating a maximum flow rate of 41 µL min −1 and operating against a high backpressure of up to 25 kPa. In addition, a lumped-parameter theoretical model for the planar micropump is also developed for accurate analysis of the device behavior. These results demonstrate the capability of this micropump for diverse applications in lab-on-a-chip systems.

Leukocyte telomere length and mortality among U.S. adults: Effect modification by physical activity behaviour.

Science.gov (United States)

Loprinzi, Paul D; Loenneke, Jeremy P

2018-01-01

The purpose of this study was to examine the association between leukocyte telomere length (LTL) and mortality (outcome variable), with consideration by physical activity behaviour. Data from the 1999-2002 National Health and Nutrition Examination Survey were employed (N = 6,611; 20-85 yrs), with follow-up mortality assessment through 31 December 2006. DNA was extracted from whole blood to assess LTL via quantitative polymerase chain reaction. Compared to those in the first LTL tertile, the adjusted hazard ratio for all-cause mortality for those in the 2 nd and 3 rd LTL tertiles, respectively, was 0.82 (95% CI: 0.60-1.12; P = .22) and 0.76 (95% CI: 0.50-1.14; P = .18). However, after adjustments, LTL tertile 3 (vs. 1) was associated with all-cause mortality (HR = 0.37; 95% CI: 0.14-0.93; P = .03) for those who engaged in moderate-intensity exercise. Similarly, LTL was associated with CVD-specific mortality for those who engaged in moderate-intensity exercise (HR = 0.17; 95% CI: 0.04-0.73; P = .02). Longer telomeres are associated with increased survival, particularly among men and those who are active, underscoring the importance of promotion of physical activity behaviour.

High-resolution MR imaging of the proximal zone of the lunotriquetral ligament with a microscopy coil

International Nuclear Information System (INIS)

Yoshioka, Hiroshi; Carrino, John A.; Lang, Philipp; Winalski, Carl S.; Tanaka, Toshikazu; Ueno, Teruko; Shindo, Masashi

2006-01-01

To evaluate high-resolution MRI of the proximal zone of the lunotriquetral ligament (LTL) using a microscopy surface coil with a 1.5 T scanner. The proximal zone of the LTL was reviewed in 90 subjects (23 asymptomatic normal volunteers and 67 patients with suspicion of triangular fibrocartilage complex injury) with high-resolution MRI using a 47-mm microscopy surface coil. High-resolution MR images were obtained with gradient recalled echo (GRE) T2*-weighted sequence and short tau inversion recovery imaging, with a 1- to 1.5-mm slice thickness, a 50-mm field of view, an imaging matrix of 140-224 x 512 using zero fill interpolation, and 3-4 excitations. As a qualitative analysis, the LTL was classified in shape and signal intensity. The triangle-shaped low-signal-intensity LTL was identified in 77 of 90 subjects (85.6%) on GRE images. The triangle was classified as regular (41.1%), broad-based (20.0%), narrow-based (6.7%), or asymmetrical (17.8%). The bar-shaped ligament was seen in one patient, and unclassified ligaments were seen in 12 patients. All volunteers showed triangle-shaped LTL. The MR signal intensity of the proximal zone in the LTL was characterized as homogeneously low intensity (type 1; 33.8%). (orig.)

High-resolution MR imaging of the proximal zone of the lunotriquetral ligament with a microscopy coil

Energy Technology Data Exchange (ETDEWEB)

Yoshioka, Hiroshi; Carrino, John A.; Lang, Philipp; Winalski, Carl S. [Brigham and Women' s Hospital, Department of Radiology, Boston, MA (United States); Tanaka, Toshikazu [Tsukuba Memorial Hospital, Department of Orthopedic Surgery, Tsukuba (Japan); Ueno, Teruko [University of Tsukuba, Department of Radiology, Tsukuba (Japan); Shindo, Masashi [Tsukuba University Hospital, Tsukuba (Japan)

2006-05-15

To evaluate high-resolution MRI of the proximal zone of the lunotriquetral ligament (LTL) using a microscopy surface coil with a 1.5 T scanner. The proximal zone of the LTL was reviewed in 90 subjects (23 asymptomatic normal volunteers and 67 patients with suspicion of triangular fibrocartilage complex injury) with high-resolution MRI using a 47-mm microscopy surface coil. High-resolution MR images were obtained with gradient recalled echo (GRE) T2*-weighted sequence and short tau inversion recovery imaging, with a 1- to 1.5-mm slice thickness, a 50-mm field of view, an imaging matrix of 140-224 x 512 using zero fill interpolation, and 3-4 excitations. As a qualitative analysis, the LTL was classified in shape and signal intensity. The triangle-shaped low-signal-intensity LTL was identified in 77 of 90 subjects (85.6%) on GRE images. The triangle was classified as regular (41.1%), broad-based (20.0%), narrow-based (6.7%), or asymmetrical (17.8%). The bar-shaped ligament was seen in one patient, and unclassified ligaments were seen in 12 patients. All volunteers showed triangle-shaped LTL. The MR signal intensity of the proximal zone in the LTL was characterized as homogeneously low intensity (type 1; 33.8%). (orig.)

Checking BEBC superconducting magnet

CERN Multimedia

CERN PhotoLab

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.

Quality checking of radioactive and hazardous waste

International Nuclear Information System (INIS)

Billington, D.M.; Burgoyne, S.M.J.; Dale, C.J.

1992-01-01

This report describes the work of the HMIP Waste Quality Checking Laboratory (WQCL) for the period September 1989 -August 1991. The WQCL has conducted research and development of procedures for the receipt, sampling and analysis of low level solid radioactive waste (LLW), intermediate level radioactive waste (ILW) and hazardous chemical waste (HW). Operational facilities have been commissioned for quality checking both LLW and HW. Waste quality checking has been completed on LLW packages seized from the UK waste disposal route by HMIP Inspectors. Packages have ranged in size from the 200 litre steel drum to half-height ISO freight container. Development work was continued on methods of sample extraction and radio-chemical analysis for cement encapsulated ILW in the form of magnox, graphite and stainless steel. This work was undertaken on non-radioactive simulants. (author)

Checking Consistency of Pedigree Information is NP-complete

DEFF Research Database (Denmark)

Aceto, Luca; Hansen, Jens A.; Ingolfsdottir, Anna

Consistency checking is a fundamental computational problem in genetics. Given a pedigree and information on the genotypes of some of the individuals in it, the aim of consistency checking is to determine whether these data are consistent with the classic Mendelian laws of inheritance. This probl...

Model Checking Discounted Temporal Properties

NARCIS (Netherlands)

de Alfaro, Luca; Faella, Marco; Henzinger, Thomas A.; Majumdar, Rupak; Stoelinga, Mariëlle Ida Antoinette

2005-01-01

Temporal logic is two-valued: a property is 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 present a

Model Checking Discounted Temporal Properties

NARCIS (Netherlands)

de Alfaro, Luca; Faella, Marco; Henzinger, Thomas A.; Majumdar, Rupak; Stoelinga, Mariëlle Ida Antoinette; Jensen, K; Podelski, A.

2004-01-01

Temporal logic is two-valued: a property is 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 present a

A cost-benefit analysis of alternative device configurations for aviation-checked baggage security screening.

Science.gov (United States)

Jacobson, Sheldon H; Karnani, Tamana; Kobza, John E; Ritchie, Lynsey

2006-04-01

The terrorist attacks of September 11, 2001 have resulted in dramatic changes in aviation security. As of early 2003, an estimated 1,100 explosive detection systems (EDS) and 6,000 explosive trace detection machines (ETD) have been deployed to ensure 100% checked baggage screening at all commercial airports throughout the United States. The prohibitive costs associated with deploying and operating such devices is a serious issue for the Transportation Security Administration. This article evaluates the cost effectiveness of the explosive detection technologies currently deployed to screen checked baggage as well as new technologies that could be used in the future. Both single-device and two-device systems are considered. In particular, the expected annual direct cost of using these devices for 100% checked baggage screening under various scenarios is obtained and the tradeoffs between using single- and two-device strategies are studied. The expected number of successful threats under the different checked baggage screening scenarios with 100% checked baggage screening is also obtained. Lastly, a risk-based screening strategy proposed in the literature is analyzed. The results reported suggest that for the existing security setup, with current device costs and probability parameters, single-device systems are less costly and have fewer expected number of successful threats than two-device systems due to the way the second device affects the alarm or clear decision. The risk-based approach is found to have the potential to significantly improve security. The cost model introduced provides an effective tool for the execution of cost-benefit analyses of alternative device configurations for aviation-checked baggage security screening.

First experiences with the LHC BLM sanity checks

CERN Document Server

Emery, J; Effinger, E; Nordt, A; Sapinski, M G; Zamantzas, C

2010-01-01

The reliability concerns have driven the design of the Large Hardron Collider (LHC) Beam Loss Monitoring (BLM) system from the early stage of the studies up to the present commissioning and the latest development of diagnostic tools. To protect the system against non-conformities, new ways of automatic checking have been developed and implemented. These checks are regularly and systematically executed by the LHC operation team to ensure that the system status is after each test "as good as new". The sanity checks are part of this strategy. They are testing the electrical part of the detectors (ionisation chamber or secondary emission detector), their cable connections to the front-end electronics, further connections to the back-end electronics and their ability to request a beam abort. During the installation and in the early commissioning phase, these checks have shown their ability to find also non-conformities caused by unexpected failure event scenarios. In every day operation, a non-conformity discovere...

Review and analysis of check valve failure data

International Nuclear Information System (INIS)

Todd, M.D.; Casada, D.A.

1992-01-01

Check valve operating problems in recent years have resulted in significant operating transients, increased cost and decreased system availability. There has been, in response, additional attention given to check valves by utilities, as well as the US Nuclear Regulatory Commission and the American Society of Mechanical Engineers Operation and Maintenance Committee. All these organizations have the fundamental goal of ensuring reliable operation of check valves. A key ingredient to an engineering-oriented reliability improvement effort is a thorough understanding of relevant historical experience. Oak Ridge National Laboratory is currently conducting a detailed review of historical failure data available through the Institute of Nuclear Power Operation's Nuclear Plant Reliability Data System. The focus of the review is on check valve failures that have involved significant degradation of the valve internal parts. A variety of parameters are being considered during the review, including size, age, system of service, method of failure discovery, the affected valve parts, attributed causes, and corrective actions

Telomere Shortening in Neurological Disorders: An Abundance of Unanswered Questions

OpenAIRE

Eitan, Erez; Hutchison, Emmette R.; Mattson, Mark P.

2014-01-01

Telomeres, ribonucleoprotein complexes that cap eukaryotic chromosomes, typically shorten in leukocytes with aging. Aging is a primary risk factor for neurodegenerative disease (ND), and a common assumption has arisen that leukocyte telomere length (LTL) can serve as a predictor of neurological disease. However, the evidence for shorter LTL in Alzheimer’s and Parkinson’s patients is inconsistent. The diverse causes of telomere shortening may explain variability in LTL between studies and indi...

Safety and Availability Checking for User Authorization Queries in RBAC

Directory of Open Access Journals (Sweden)

Jian-feng Lu

2012-09-01

Full Text Available This paper introduces the notion of safety and availability checking for user authorization query processing, and develop a recursive algorithm use the ideas from backtracking-based search techniques to search for the optimal solution. For the availability checking, we introduce the notion of max activatable set (MAS, and show formally how MAS can be determined in a hybrid role hierarchy. For the safety checking, we give a formal definition of dynamic separation-of-duty (DSoD policies, and show how to reduce the safety checking for DSoD to a SAT instance.

The Activity Check of Brachytherapy Isotope

International Nuclear Information System (INIS)

Kim, Gun Oh; Lee, Byung Koo; Kwon, Young Ho

2004-01-01

An isotope Ir-192, which is used in brachytherapy depends on import in whole quantities. There are a few ways for its activity. measurement using Welltype chamber or the way to rely on authentic decay table of manufacturer. In-air dosimetry using Farmer Chamber, etc. In this paper, let me introduce the way using Farmer chamber which is easier and simple. With the Farmer chamber and source calibration jig, take a measurement the activity of an isotope Ir-192 and compare the value with the value from decay table of manufacturer and check the activity of source. The result of measurement, compared the value from decay table, by ±2.1. (which belongs to recommendable value for AAPM ±5% as difference of error range). It is possible to use on clinical medicine. With the increase in use of brachytherapy, the increase of import is essential. And an accurate activity check of source is compulsory. For the activity check of source, it was possible to use Farmer chamber and source calibration jig without additional purchase of Well type chamber.

31 CFR 211.1 - Withholding delivery of checks.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Withholding delivery of checks. 211.1 Section 211.1 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE, DEPARTMENT OF THE TREASURY FINANCIAL MANAGEMENT SERVICE DELIVERY OF CHECKS AND WARRANTS TO...

Delivery quality assurance with ArcCHECK

International Nuclear Information System (INIS)

Neilson, Christopher; Klein, Michael; Barnett, Rob; Yartsev, Slav

2013-01-01

Radiation therapy requires delivery quality assurance (DQA) to ensure that treatment is accurate and closely follows the plan. We report our experience with the ArcCHECK phantom and investigate its potential optimization for the DQA process. One-hundred seventy DQA plans from 84 patients were studied. Plans were classified into 2 groups: those with the target situated on the diodes of the ArcCHECK (D plans) and those with the target situated at the center (C plans). Gamma pass rates for 8 target sites were examined. The parameters used to analyze the data included 3%/3 mm with the Van Dyk percent difference criteria (VD) on, 3%/3 mm with the VD off, 2%/2 mm with the VD on, and x/3 mm with the VD on and the percentage dosimetric agreement “x” for diode plans adjusted. D plans typically displayed maximum planned dose (MPD) on the cylindrical surface containing ArcCHECK diodes than center plans, resulting in inflated gamma pass rates. When this was taken into account by adjusting the percentage dosimetric agreement, C plans outperformed D plans by an average of 3.5%. ArcCHECK can streamline the DQA process, consuming less time and resources than radiographic films. It is unnecessary to generate 2 DQA plans for each patient; a single center plan will suffice. Six of 8 target sites consistently displayed pass rates well within our acceptance criteria; the lesser performance of head and neck and spinal sites can be attributed to marginally lower doses and increased high gradient of plans

Assessment of diagnostic methods for determining degradation of check valves

International Nuclear Information System (INIS)

Haynes, H.D.; Farmer, W.S.

1992-01-01

The Oak Ridge National Laboratory (ORNL) has carried out a comprehensive aging assessment of check valves in support of the Nuclear Plant Aging Research (NPAR) program. This paper provides a summary of the ORNL check valve aging assessment with emphasis on the identification, evaluation, and application of check valve monitoring methods and techniques. Several check valve monitoring methods are described and compared. These methods include: acoustic emission monitoring, ultrasonic inspection, magnetic flux signature analysis (MFSA), external magnetics. These diagnostic technologies were shown to be useful in determining check valve condition (e.g., disc position, disc motion, and seat leakage), although none of the methods was by itself, successful in monitoring all three condition indicators. The combination of acoustic emission with either ultrasonics or one of the magnetic technologies, however, yields a monitoring system that succeeds in providing the sensitivity to detect all major check valve operating conditions. Other areas covered in the paper include descriptions of relevant regulatory issues, utility group activities, and interactions ORNL has had with outside organizations for the purpose of disseminating research results

Radioactive check sources for alpha and beta sensitive radiological instrumentation

International Nuclear Information System (INIS)

Barnett, J.M.; Kane, J.E. II.

1994-06-01

Since 1991, the Westinghouse Hanford Company has examined the construction and use of alpha and beta radioactive check sources for calibrating instruments and for performing response checks of instruments used for operational and environmental radiation detection. The purpose of using a radioactive check source is to characterize the response of a radiation monitoring instrument in the presence of radioactivity. To accurately calibrate the instrument and check its response, the check source used must emulate as closely as possible the actual physical and isotopic conditions being monitored. The isotope employed and the physical methods used to fabricate the check source (among other factors) determine instrument response. Although information from applicable national and international standards, journal articles, books, and government documents was considered, empirical data collected is most valuable when considering the type of source to use for a particular application. This paper presents source construction methods, use considerations, and standard recommendations. The results of a Hanford Site evaluation of several types of alpha and beta sources are also given

Double checking medicines: defence against error or contributory factor?

Science.gov (United States)

Armitage, Gerry

2008-08-01

The double checking of medicines in health care is a contestable procedure. It occupies an obvious position in health care practice and is understood to be an effective defence against medication error but the process is variable and the outcomes have not been exposed to testing. This paper presents an appraisal of the process using data from part of a larger study on the contributory factors in medication errors and their reporting. Previous research studies are reviewed; data are analysed from a review of 991 drug error reports and a subsequent series of 40 in-depth interviews with health professionals in an acute hospital in northern England. The incident reports showed that errors occurred despite double checking but that action taken did not appear to investigate the checking process. Most interview participants (34) talked extensively about double checking but believed the process to be inconsistent. Four key categories were apparent: deference to authority, reduction of responsibility, automatic processing and lack of time. Solutions to the problems were also offered, which are discussed with several recommendations. Double checking medicines should be a selective and systematic procedure informed by key principles and encompassing certain behaviours. Psychological research may be instructive in reducing checking errors but the aviation industry may also have a part to play in increasing error wisdom and reducing risk.

Informatization tools (means of study effectiveness checking based on hierarchy system of tasks

Directory of Open Access Journals (Sweden)

Сергей Викторович Криволапов

2010-09-01

Full Text Available Study effectiveness checking system, based on tasks hierarchy system is considered in this article. Introduced performance score model, can not only helps along time saving and teacher's work facilitation but gives more objective appraisal of student's knowledge.

Related Fact Checks: a tool for combating fake news

OpenAIRE

Guha, Sreya

2017-01-01

The emergence of "Fake News" and misinformation via online news and social media has spurred an interest in computational tools to combat this phenomenon. In this paper we present a new "Related Fact Checks" service, which can help a reader critically evaluate an article and make a judgment on its veracity by bringing up fact checks that are relevant to the article. We describe the core technical problems that need to be solved in building a "Related Fact Checks" service, and present results ...

Check-up Measurement (update). Deliverable D5.22

NARCIS (Netherlands)

Holtzer, A.C.G.; Giessen, A.M.D. van der; Djurica, M.

2015-01-01

This deliverable D5.22 presents the GEN6 check-up measurement. It describes the most prominent outcomes of the GEN6 project up to this point in time. The check-up measurement helps to focus the monitoring towards the most relevant achievements of the project, such that an efficient and well-targeted

On the Use of Static Checking in the Verification of Interlocking Systems

DEFF Research Database (Denmark)

Haxthausen, Anne Elisabeth; Østergaard, Peter H.

2016-01-01

In the formal methods community, the correctness of interlocking tables is typically verified by model checking. This paper suggests to use a static checker for this purpose and it demonstrates for the RobustRailS verification tool set that the execution time and memory usage of its static checker...

Treasury Check Verification Query (TCVQ)

Data.gov (United States)

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...

Progress Check Module; Basic Electricity and Electronics Individualized Learning System. Progress Check Booklet.

Science.gov (United States)

Bureau of Naval Personnel, Washington, DC.

The Progress Check Booklet is designed to be used by the student working in the programed course to determine if he has mastered the concepts in the course booklets on: electrical current; voltage; resistance; measuring current and voltage in series circuits; relationships of current, voltage, and resistance; parellel circuits; combination…

A Software Tool for Legal Drafting

Directory of Open Access Journals (Sweden)

Daniel Gorín

2011-09-01

Full Text Available Although many attempts at automated aids for legal drafting have been made, they were based on the construction of a new tool, completely from scratch. This is at least curious, considering that a strong parallelism can be established between a normative document and a software specification: both describe what an entity should or should not do, can or cannot do. In this article we compare normative documents and software specifications to find out their similarities and differences. The comparison shows that there are distinctive particularities, but they are restricted to a very specific subclass of normative propositions. The rest, we postulate, can be dealt with software tools. For such an enterprise the FormaLex tool set was devised: an LTL-based language and companion tools that utilize model checking to find out normative incoherences in regulations, contracts and other legal documents. A feature-rich case study is analyzed with the presented tools.

31 CFR 10.31 - Negotiation of taxpayer checks.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Negotiation of taxpayer checks. 10.31 Section 10.31 Money and Finance: Treasury Office of the Secretary of the Treasury PRACTICE BEFORE THE INTERNAL REVENUE SERVICE Duties and Restrictions Relating to Practice Before the Internal Revenue Service § 10.31 Negotiation of taxpayer checks. ...

Model Checking of a Diabetes-Cancer Model

Science.gov (United States)

Gong, Haijun; Zuliani, Paolo; Clarke, Edmund M.

2011-06-01

Accumulating evidence suggests that cancer incidence might be associated with diabetes mellitus, especially Type II diabetes which is characterized by hyperinsulinaemia, hyperglycaemia, obesity, and overexpression of multiple WNT pathway components. These diabetes risk factors can activate a number of signaling pathways that are important in the development of different cancers. To systematically understand the signaling components that link diabetes and cancer risk, we have constructed a single-cell, Boolean network model by integrating the signaling pathways that are influenced by these risk factors to study insulin resistance, cancer cell proliferation and apoptosis. Then, we introduce and apply the Symbolic Model Verifier (SMV), a formal verification tool, to qualitatively study some temporal logic properties of our diabetes-cancer model. The verification results show that the diabetes risk factors might not increase cancer risk in normal cells, but they will promote cell proliferation if the cell is in a precancerous or cancerous stage characterized by losses of the tumor-suppressor proteins ARF and INK4a.

42 CFR 433.40 - Treatment of uncashed or cancelled (voided) Medicaid checks.

Science.gov (United States)

2010-10-01

...) Medicaid checks. 433.40 Section 433.40 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT...) Medicaid checks. (a) Purpose. This section provides the rules to ensure that States refund the Federal...— Cancelled (voided) check means a Medicaid check issued by a State or fiscal agent which prior to its being...

Food Security and Leukocyte Telomere Length in Adult Americans

Directory of Open Access Journals (Sweden)

Mohsen Mazidi

2017-01-01

Full Text Available Background and Purpose. Leukocyte telomere length (LTL is a biomarker of biologic age. Whether food security status modulates LTL is still unknown. We investigated the association between food security and LTL in participants of the 1999–2002 US National Health and Nutrition Examination Survey (NHANES. Methods. Analysis of covariance (ANCOVA was used to evaluate the association between food security categories and LTL controlling for sex, race, and education and accounting for the survey design and sample weights. Results. We included 10,888 participants with 5228 (48.0% being men. They were aged on average 44.1 years. In all, 2362 (21.7% had less than high school, 2787 (25.6% had achieved high school, while 5705 (52.5% had done more than high school. In sex-, race-, and education-adjusted ANCOVA, average LTL (T/S ratio for participants with high food security versus those with marginal, low, or very low food security was 1.32 versus 1.20 for the age group 25–35 years and 1.26 versus 1.11 for the 35–45 years, (p<0.001. Conclusion. The association between food insecurity and LTL shortening in young adults suggest that some of the future effects of food insecurity on chronic disease risk in this population could be mediated by telomere shortening.

Dysregulated physiological stress systems and accelerated cellular aging.

Science.gov (United States)

Révész, Dóra; Verhoeven, Josine E; Milaneschi, Yuri; de Geus, Eco J C N; Wolkowitz, Owen M; Penninx, Brenda W J H

2014-06-01

Exposure to chronic stressors is associated with accelerated biological aging as indicated by reduced leukocyte telomere length (LTL). This impact could be because of chronic overactivation of the body's physiological stress systems. This study examined the associations between LTL and the immune system, hypothalamic-pituitary-adrenal axis and autonomic nervous system. LTL was assessed in 2936 adults from the Netherlands Study of Depression and Anxiety. Inflammation markers (interleukin-6, c-reactive protein, tumor necrosis factor-alpha), hypothalamic-pituitary-adrenal-axis indicators (salivary cortisol awakening curve [area under the curve indicators, with respect to the ground and increase], evening levels, 0.5 mg dexamethasone cortisol suppression ratio), and autonomic nervous system measures (heart rate, respiratory sinus arrhythmia, pre-ejection period) were determined. Linear regression analyses were performed and adjusted for sociodemographic, lifestyle and clinical factors. Shorter LTL was significantly associated with higher c-reactive protein, interleukin-6, area under the curve with respect to increase, and heart rate. A cumulative index score was calculated based on the number of highest tertiles of these 4 stress markers. LTL demonstrated a significant gradient within subjects ranging from having zero (5528 base pairs) to having 4 elevated stress markers (5371 base pairs, p for trend = 0.002), corresponding to a difference of 10 years of accelerated biological aging. Contrary to the expectations, shorter LTL was also associated with longer pre-ejection period, indicating lower sympathetic tone. This large-scale study showed that inflammation, high awakening cortisol response, and increased heart rate are associated with shorter LTL, especially when they are dysregulated cumulatively. Copyright © 2014 Elsevier Inc. All rights reserved.

Pre-Alignment Checks. Automotive Mechanics. Steering & Suspension. Instructor's Guide [and] Student Guide.

Science.gov (United States)

Spignesi, B.

This instructional package, one in a series of individualized instructional units on automotive steering and suspension, consists of a student guide and an instructor guide dealing with prealignment checks. Covered in the module are the following steps in a prealignment check: checking the ride height of a vehicle, checking the ball joints and the…

Is drive for muscularity related to body checking behaviors in men athletes?

Directory of Open Access Journals (Sweden)

Leonardo de Sousa Fortes

Full Text Available Abstract The aim of this study was to analyze the relationship between drive for muscularity and body checking behaviors in men athletes. Two hundred and twelve Brazilian athletes over 15 years of age participated. We used the Drive for Muscularity Scale (DMS to evaluate the drive for muscularity. The Male Body Checking Questionnaire was used to assess body checking behaviors. The findings demonstrated a relationship between the "body image-oriented muscularity" subscale of the DMS and body checking behaviors (p = 0.001. The results indicated differences in body checking among athletes with high and low levels of drive for muscularity. We concluded that drive for muscularity was related to body checking behaviors in men athletes.

Assessing Personality and Mood With Adjective Check List Methodology: A Review

Science.gov (United States)

Craig, Robert J.

2005-01-01

This article addresses the benefits and problems in using adjective check list methodology to assess personality. Recent developments in this assessment method are reviewed, emphasizing seminal adjective-based personality tests (Gough's Adjective Check List), mood tests (Lubin's Depressive Adjective Test, Multiple Affect Adjective Check List),…

CrossCheck plagiarism screening : Experience of the Journal of Epidemiology

Science.gov (United States)

Hashimoto, Katsumi

Due to technological advances in the past two decades, researchers now have unprecedented access to a tremendous amount of useful information. However, because of the extreme pressure to publish, this abundance of information can sometimes tempt researchers to commit scientific misconduct. A serious form of such misconduct is plagiarism. Editors are always concerned about the possibility of publishing plagiarized manuscripts. The plagiarism detection tool CrossCheck allows editors to scan and analyze manuscripts effectively. The Journal of Epidemiology took part in a trial of CrossCheck, and this article discusses the concerns journal editors might have regarding the use of CrossCheck and its analysis. In addition, potential problems identified by CrossCheck, including self-plagiarism, are introduced.

Diagnostic framework and health check tool for engineering and technology projects

Directory of Open Access Journals (Sweden)

Simon P Philbin

2014-10-01

Full Text Available Purpose: Development of a practitioner oriented diagnostic framework and health check tool to support the robust assessment of engineering and technology projects.Design/methodology/approach: The research is based on a literature review that draws together insights on project assessment and critical success factors to establish an integrated systems view of projects. This is extended to allow a comprehensive diagnostic framework to be developed along with a high-level health check tool that can be readily deployed on projects. The utility of the diagnostic framework and health check tool are explored through three illustrative case studies, with two from Canada and one from the United Kingdom. Findings andOriginality/value: The performance of engineering and technology projects can be viewed through a systems perspective and being a function of six sub-systems that are: process, technology, resources, impact, knowledge and culture. The diagnostic framework that is developed through this research integrates these sub-systems to provide a comprehensive assessment methodology for projects, which is linked to existing best practice for project reviews, performance management and maturity models. The case studies provide managerial insights that are related to the diagnostic framework but crucially also position the approach in the context of industrial applications for construction engineering and technology management.Research limitations/implications: The case study approach includes two case studies from the construction and facilities development sector with the third case study from the research and technology sector. Further work is required to investigate the use of the diagnostic framework and health check tool in other sectors.Practical implications: The health check tool will be of practical benefit to new projects managers that require access to a robust and convenient project review methodology for assessing the status and health of a

Water hammer analysis. Dynamic simulation model check valve piston; Analisis del golpe de airete. Modelo de simulacion dinamica de valvula de retencion piston

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)

Experimental investigation of the check valve behaviour when the flow is reversing

Directory of Open Access Journals (Sweden)

Himr D.

2017-01-01

Full Text Available Check valve in a pipeline is supposed to prevent the reverse flow and to allow the flow in the positive direction. The construction of check valves follows these requirements, but the check valve must not cause pressure pulsations in transients. It means when the fluid is accelerating or decelerating. The article describes an experimental investigation of a swing check valve when the flow is changing its direction. The check valve was placed in an experimental circuit, where the pressure on the upstream and downstream side of the valve was measured and the current value of flow rate was determined. The goal was to simulate conditions in the real system, where the check valve slam had been observed.

Masking potency and whiteness of noise at various noise check sizes.

Science.gov (United States)

Kukkonen, H; Rovamo, J; Näsänen, R

1995-02-01

The masking effect of spatial noise can be increased by increasing either the rms contrast or check size of noise. In this study, the authors investigated the largest noise check size that still mimics the effect of white noise in grating detection and how it depends on the bandwidth and spatial frequency of a grating. The authors measured contrast energy thresholds, E, for vertical cosine gratings at various spatial frequencies and bandwidths. Gratings were embedded in two-dimensional spatial noise. The side length of the square noise checks was varied in the experiments. The spectral density, N(0,0), of white spatial noise at zero frequency was calculated by multiplying the noise check area by the rms contrast of noise squared. The physical signal-to-noise ratio at threshold [E/N(0,0)]0.5 was initially constant but then started to decrease. The largest noise check that still produced a constant physical signal-to-noise ratio at threshold was directly proportional to the spatial frequency. When expressed as a fraction of grating cycle, the largest noise check size depended only on stimulus bandwidth. The smallest number of noise checks per grating cycle needed to mimic the effect of white noise decreased from 4.2 to 2.6 when the number of grating cycles increased from 1 to 64. Spatial noise can be regarded as white in grating detection if there are at least four square noise checks per grating cycle at all spatial frequencies.

LHCb: Analysing DIRAC's Behavior using Model Checking with Process Algebra

CERN Multimedia

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...

Intelligent Data Visualization for Cross-Checking Spacecraft System Diagnosis

Science.gov (United States)

Ong, James C.; Remolina, Emilio; Breeden, David; Stroozas, Brett A.; Mohammed, John L.

2012-01-01

Any reasoning system is fallible, so crew members and flight controllers must be able to cross-check automated diagnoses of spacecraft or habitat problems by considering alternate diagnoses and analyzing related evidence. Cross-checking improves diagnostic accuracy because people can apply information processing heuristics, pattern recognition techniques, and reasoning methods that the automated diagnostic system may not possess. Over time, cross-checking also enables crew members to become comfortable with how the diagnostic reasoning system performs, so the system can earn the crew s trust. We developed intelligent data visualization software that helps users cross-check automated diagnoses of system faults more effectively. The user interface displays scrollable arrays of timelines and time-series graphs, which are tightly integrated with an interactive, color-coded system schematic to show important spatial-temporal data patterns. Signal processing and rule-based diagnostic reasoning automatically identify alternate hypotheses and data patterns that support or rebut the original and alternate diagnoses. A color-coded matrix display summarizes the supporting or rebutting evidence for each diagnosis, and a drill-down capability enables crew members to quickly view graphs and timelines of the underlying data. This system demonstrates that modest amounts of diagnostic reasoning, combined with interactive, information-dense data visualizations, can accelerate system diagnosis and cross-checking.

Social-cognitive determinants of the tick check: a cross-sectional study on self-protective behavior in combatting Lyme disease.

Science.gov (United States)

van der Heijden, Amy; Mulder, Bob C; Poortvliet, P Marijn; van Vliet, Arnold J H

2017-11-25

Performing a tick check after visiting nature is considered the most important preventive measure to avoid contracting Lyme disease. Checking the body for ticks after visiting nature is the only measure that can fully guarantee whether one has been bitten by a tick and provides the opportunity to remove the tick as soon as possible, thereby greatly reducing the chance of contracting Lyme disease. However, compliance to performing the tick check is low. In addition, most previous studies on determinants of preventive measures to avoid Lyme disease lack a clear definition and/or operationalization of the term "preventive measures". Those that do distinguish multiple behaviors including the tick check, fail to describe the systematic steps that should be followed in order to perform the tick check effectively. Hence, the purpose of this study was to identify determinants of systematically performing the tick check, based on social cognitive theory. A cross-sectional self-administered survey questionnaire was filled out online by 508 respondents (M age  = 51.7, SD = 16.0; 50.2% men; 86.4% daily or weekly nature visitors). Bivariate correlations and multivariate regression analyses were conducted to identify associations between socio-cognitive determinants (i.e. concepts related to humans' intrinsic and extrinsic motivation to perform certain behavior), and the tick check, and between socio-cognitive determinants and proximal goal to do the tick check. The full regression model explained 28% of the variance in doing the tick check. Results showed that performing the tick check was associated with proximal goal (β = .23, p theory to identify determinants. Based on the results, a number of practical recommendations can be made to promote the performance of the tick check.

Study of check image using computed radiography

International Nuclear Information System (INIS)

Sato, Hiroshi

2002-01-01

There are two image forming methods both a check image and a portal image in the linacogram. It has been established the image forming method in the check image using computed radiography (CR). On the other hand, it is not established the image forming method in the portal image using CR yet. Usually, in the electric portal imaging device (EPID) is mainly used just before radiotherapy start. The usefulness of the portal image forming method by CR using in place of EPID is possible to confirm the precision for determining to specific position at the irradiate part and to the irradiate method for the human organs. There are some technical problems that, since in the early time, the linac graphy (LG) image have low resolution power. In order to improve to the resolution power in LG image, CR image technologies have been introduced to the check image forming method. Heavy metallic sheet (HMS) is used to the front side of CR-IP cassette, and high contactness sponge is used to the back side of the cassette. Improved contactness between HMS and imaging plate (IP) by means of the high contactness sponge contributed to improve the resolution power in the check images. A lot of paper which is connected with these information have been reported. Imaging plate ST-III should be used to maintain high sensitivity in the check film image forming method. The same image forming method in the check image established by CR has been introduced into the portal image forming method in order to improve the resolution power. However, as a result, it couldn't acquired high resolution image forming in the portal images because of the combination of ST-III and radiotherapy dose. After several trials, it has been recognized that HR-V imaging plate for mammography is the most useful application to maintain high resolution power in the portal images. Also, it is possible to modify the image quality by changing GS parameter which is one of image processing parameters in CR. Furthermore, in case

Effective ambiguity checking in biosequence analysis

Directory of Open Access Journals (Sweden)

Giegerich Robert

2005-06-01

Full Text Available Abstract Background Ambiguity is a problem in biosequence analysis that arises in various analysis tasks solved via dynamic programming, and in particular, in the modeling of families of RNA secondary structures with stochastic context free grammars. Several types of analysis are invalidated by the presence of ambiguity. As this problem inherits undecidability (as we show here from the namely problem for context free languages, there is no complete algorithmic solution to the problem of ambiguity checking. Results We explain frequently observed sources of ambiguity, and show how to avoid them. We suggest four testing procedures that may help to detect ambiguity when present, including a just-in-time test that permits to work safely with a potentially ambiguous grammar. We introduce, for the special case of stochastic context free grammars and RNA structure modeling, an automated partial procedure for proving non-ambiguity. It is used to demonstrate non-ambiguity for several relevant grammars. Conclusion Our mechanical proof procedure and our testing methods provide a powerful arsenal of methods to ensure non-ambiguity.

Simulation of the behaviour of a servo actuated check valve upon rupture of the feedwater pipe

International Nuclear Information System (INIS)

Lucas, A.M. de; Perezagua, R.L.; Rosa, B. de la; Sanz, J.

1995-01-01

The steam generator replacement programme at Almaraz NPP, provides for the installation of a replacement damped non-return valve for the feedwater system. the function of this valve is to protect the steam generator in the event of a rupture in the feedwater pipe. Sudden closure of the check valve, against the flow and following rupture of the feedwater pipe, causes overpressure in the valve which is transmitted to the steam generator nozzle. It is therefore necessary to know this when designing the internal systems of the steam generator. Using the RELAP5/MODE3 code, it has been possible to simulate the dynamic behaviour of a check valve upon rupture of a feedwater pipe postulated outside the containment. The calculation model has been applied to different types of check valve. (Author)

Simulasi Low Density Parity Check (Ldpc) dengan Standar Dvb-t2

OpenAIRE

Kurniawan, Yusuf; Hafizh, Idham

2014-01-01

Artikel ini berisi implementasi simulasi encoding-decoding yang dilakukanpada suatu sampel data biner acak sesuai dengan standar yang digunakanpada Digital Video Broadcasting – Terrestrial 2nd Generation (DVB-T2),dengan menggunakan MATLAB. Low Density Parity Check (LDPC)digunakan dalam proses encoding-decoding sebagai fitur untuk melakukankoreksi kesalahan pada saat pengiriman data. Modulasi yang digunakandalam simulasi adalah BPSK dengan model kanal AWGN. Dalam simulasitersebut, diperbanding...

Acoustic emission testing of piston check valves

International Nuclear Information System (INIS)

Stewart, D.L.

1994-01-01

Based on test experience at Comanche Peak Unit 1, an acoustic emission data evaluation matrix for piston check valves has been developed. The degradations represented in this matrix were selected based on Edwards piston check valve failure data reported in the Nuclear Plant Reliability Data System. Evidence to support this matrix was collected from site test data on a variety of valve types. Although still under refinement, the matrix provides three major attributes for closure verification, which have proven useful in developing test procedures for inservice testing and preventing unnecessary disassembly

Checking in: An Analysis of the (Lack of) Body Checking in Women's Ice Hockey

Science.gov (United States)

Weaving, Charlene; Roberts, Samuel

2012-01-01

Despite the growing popularity of women's ice hockey in North America, players continue to face limitations because of the prohibition of body checking. In this paper, we argue from a liberal feminist philosophical perspective that this prohibition reinforces existing traditional stereotypes of female athletes. Because the women's game does not…

16 CFR 240.12 - Checking customer's use of payments.

Science.gov (United States)

2010-01-01

... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Checking customer's use of payments. 240.12 Section 240.12 Commercial Practices FEDERAL TRADE COMMISSION GUIDES AND TRADE PRACTICE RULES GUIDES FOR ADVERTISING ALLOWANCES AND OTHER MERCHANDISING PAYMENTS AND SERVICES § 240.12 Checking customer's use of...

Regular Check-Ups Are Important

Science.gov (United States)

... Attack Wear Red for Heart Health Tools for Pregnant Women, New Moms, Women Considering Pregnancy Be a Healthy ... your community (i.e. a faith-based setting, workplace, school, or civic group) ... screening on National Women’s Check-Up Day (the day after Mother’s Day ...

Progress realized by numerized Eddy current checking-chains

International Nuclear Information System (INIS)

Guerin, F.; Blanchet, A.

1985-01-01

Until the last ten years , the tubes of the Steam Generators of the Nuclear Stations were inspected by means of Eddy Current with analogical checkings-chains. HBS Company has perfected a numerized checking-chain allowing transmission up to 300 m of the E.C. signals. In a near future, it will be then possible to do periodical inspections of Steam Generators from cabins located out of the reactor building [fr

Leukocyte telomere length and personality: associations with the Big Five and Type D personality traits.

Science.gov (United States)

Schoormans, D; Verhoeven, J E; Denollet, J; van de Poll-Franse, L; Penninx, B W J H

2018-04-01

Backgrounds Accelerated cellular ageing, which can be examined by telomere length (TL), may be an overarching mechanism underlying the association between personality and adverse health outcomes. This 6-year longitudinal study examined the relation between personality and leukocyte telomere length (LTL) across time among adults with a wide age-range. Data from the Netherlands Study of Depression and Anxiety were used and included patients with a depression and/or anxiety disorder and healthy controls. Overall, 2936 persons (18-65 years, 66% female) had data on LTL at baseline and 1883 persons had LTL at 6-year follow-up. The Big Five personality traits (neuroticism, extraversion, openness to experience, agreeableness, and conscientiousness) and Type D personality were assessed. Neuroticism was negatively (B = -2.11, p = 0.03) and agreeableness was positively (B = 3.84, p = 0.03) related to LTL measured across two time points, which became just non-significant after adjusting for somatic health, lifestyle factors, and recent life stress (B = -1.99, p = 0.06; and B = 3.01, p = 0.10). Type D personality was negatively (B = -50.16, p Big Five traits high neuroticism and low agreeableness, and Type D personality were associated with shorter LTL measured across a 6-year period. Associations with the Big Five traits became non-significant after controlling for somatic health, lifestyle factors, and recent life stress, yet similar trends were observed. Type D personality remained independently associated with shorter LTL after full adjustment.

An Artificially Intelligent Physical Model-Checking Approach to Detect Switching-Related Attacks on Power Systems

Energy Technology Data Exchange (ETDEWEB)

El Hariri, Mohamad [Florida Intl Univ., Miami, FL (United States); Faddel, Samy [Florida Intl Univ., Miami, FL (United States); Mohammed, Osama [Florida Intl Univ., Miami, FL (United States)

2017-11-01

Decentralized and hierarchical microgrid control strategies have lain the groundwork for shaping the future smart grid. Such control approaches require the cooperation between microgrid operators in control centers, intelligent microcontrollers, and remote terminal units via secure and reliable communication networks. In order to enhance the security and complement the work of network intrusion detection systems, this paper presents an artificially intelligent physical model-checking that detects tampered-with circuit breaker switching control commands whether, due to a cyber-attack or human error. In this technique, distributed agents, which are monitoring sectionalized areas of a given microgrid, will be trained and continuously adapted to verify that incoming control commands do not violate the physical system operational standards and do not put the microgrid in an insecure state. The potential of this approach has been tested by deploying agents that monitor circuit breakers status commands on a 14-bus IEEE benchmark system. The results showed the accuracy of the proposed framework in characterizing the power system and successfully detecting malicious and/or erroneous control commands.

Accumulative effects of indoor air pollution exposure on leukocyte telomere length among non-smokers.

Science.gov (United States)

Lin, Nan; Mu, Xinlin; Wang, Guilian; Ren, Yu'ang; Su, Shu; Li, Zhiwen; Wang, Bin; Tao, Shu

2017-08-01

Indoor air pollution is an important environmental factor that contributes to the burden of various diseases. Long-term exposure to ambient air pollution is associated with telomere shortening. However, the association between chronic indoor air pollution from household fuel combustion and leukocyte telomere length has not been studied. In our study, 137 cancer-free non-smokers were recruited. Their exposure levels to indoor air pollution from 1985 to 2014 were assessed using a face-to-face interview questionnaire, and leukocyte telomere length (LTL) was measured using a monochrome multiplex quantitative PCR method. Accumulative exposure to solid fuel usage for cooking was negatively correlated with LTL. The LTL of residents who were exposed to solid fuel combustion for three decades (LTL = 0.70 ± 0.17) was significantly shorter than that of other populations. In addition, education and occupation were related to both exposure to solid fuel and LTL. Sociodemographic factors may play a mediating role in the correlation between leukocyte telomere length and environmental exposure to indoor air pollution. In conclusion, long-term exposure to indoor air pollution may cause LTL dysfunction. Copyright © 2017 Elsevier Ltd. All rights reserved.

A novel cognitive intervention for compulsive checking: Targeting maladaptive beliefs about memory.

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Alcolado, Gillian M; Radomsky, Adam S

2016-12-01

Compulsive checking is one of the most common symptoms of obsessive-compulsive disorder (OCD). Recently it has been proposed that those who check compulsively may believe their memory is poor, rather than having an actual memory impairment. The current study sought to develop and assess a brief cognitive intervention focused on improving maladaptive beliefs about memory, as they pertain to both checking symptoms and memory performance. Participants (N = 24) with a diagnosis of OCD and clinical levels of checking symptomatology were randomly assigned either to receive two weekly 1-hour therapy sessions or to self-monitor during a similar waitlist period. Time spent checking, checking symptoms, maladaptive beliefs about memory, and visuospatial memory were assessed both pre- and post-treatment/waitlist. Results showed that compared to the waitlist condition, individuals in the treatment condition displayed significant decreases in their maladaptive beliefs about memory and checking symptoms from pre- to post-intervention. They also exhibited increased recall performance on a measure of visuospatial memory. Changes in beliefs about memory were predictors of reduced post-intervention checking, but were not predictive of increased post-intervention memory scores. The lack of long term follow-up data and use of a waitlist control leave questions about the stability and specificity of the intervention. Findings provide preliminary evidence that strategies targeting beliefs about memory may be worthy of inclusion in cognitive-behavioural approaches to treating compulsive checking. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Factors Associated with Stress Check Attendance: Possible Effect of Timing of Annual Health Examination].

Science.gov (United States)

Ishimaru, Tomohiro; Hattori, Michihiro; Nagata, Masako; Kuwahara, Keisuke; Watanabe, Seiji; Mori, Koji