Science.gov

Sample records for formal description techniques

  1. Automatic derivation of formal software specifications from informal descriptions

    NASA Technical Reports Server (NTRS)

    Miriyala, Kanth; Harandi, Mehdi T.

    1991-01-01

    SPECIFIER, an interactive system which derives formal specifications of data types and programs from their informal descriptions, is described. The process of deriving formal specifications is viewed as a problem-solving process. The system uses common problem-solving techniques such as schemas, analogy, and difference-based reasoning to derive formal specifications. If an informal description is a commonly occurring operation for which the system has a schema, then the formal specification is derived by instantiating the schema. If there is no such schema, SPECIFIER tries to find a previously solved problem which is analogous to the current problem. If the problem found is directly analogous to the current problem, it applies an analogy mapping to obtain a formal specification. On the other hand, if the analogy found is only approximate, it solves the directly analogous part of the problem by analogy and performs difference-based reasoning using the remaining (unmatched) parts to transform the formal specification obtained by analogy to a formal specification for the entire original problem.

  2. Formal Description of Trust-based Access Control

    NASA Astrophysics Data System (ADS)

    Xiaoning, Ma

    Different from traditional access control technologies, such as discretionary access control, mandatory access control, role-based access control, trust-based access control can solve the problem of uncertainty, risk and vulnerability coming from authorization. In this paper, strict definition and formal description of trust-based access control is defined.

  3. Best behaviour? Ontologies and the formal description of animal behaviour.

    PubMed

    Gkoutos, Georgios V; Hoehndorf, Robert; Tsaprouni, Loukia; Schofield, Paul N

    2015-10-01

    The development of ontologies for describing animal behaviour has proved to be one of the most difficult of all scientific knowledge domains. Ranging from neurological processes to human emotions, the range and scope needed for such ontologies is highly challenging, but if data integration and computational tools such as automated reasoning are to be fully applied in this important area the underlying principles of these ontologies need to be better established and development needs detailed coordination. Whilst the state of scientific knowledge is always paramount in ontology and formal description framework design, this is a particular problem with neurobehavioural ontologies where our understanding of the relationship between behaviour and its underlying biophysical basis is currently in its infancy. In this commentary, we discuss some of the fundamental problems in designing and using behaviour ontologies, and present some of the best developed tools in this domain.

  4. Advanced Tools and Techniques for Formal Techniques in Aerospace Systems

    NASA Technical Reports Server (NTRS)

    Knight, John C.

    2005-01-01

    This is the final technical report for grant number NAG-1-02101. The title of this grant was "Advanced Tools and Techniques for Formal Techniques In Aerospace Systems". The principal investigator on this grant was Dr. John C. Knight of the Computer Science Department, University of Virginia, Charlottesville, Virginia 22904-4740. This report summarizes activities under the grant during the period 7/01/2002 to 9/30/2004. This report is organized as follows. In section 2, the technical background of the grant is summarized. Section 3 lists accomplishments and section 4 lists students funded under the grant. In section 5, we present a list of presentations given at various academic and research institutions about the research conducted. Finally, a list of publications generated under this grant is included in section 6.

  5. Formal results regarding metric space techniques for the study of astrophysical maps

    NASA Technical Reports Server (NTRS)

    Adams, Fred C.; Wiseman, Jennifer J.

    1994-01-01

    We extend a newly developed formal system for the description of astrophyscial maps. In this formalism, we consider the difference between maps to be the distance between elements of a pseudometric space (the space of all such maps). This Ansatz allows us to measure quantitatively the difference between any two maps and to order the space of all maps. For each physical characteristic of interest, this technique assigns an 'output' function to each map; the difference between the maps is then determined from the difference between their corresponding output functions. In this present study, we show that the results of this procedure are invariant under a class of transformations of the maps and the domains of the maps. In addition, we study the propagation of errors (observational uncertainties) through this formalism. We show that the uncertainties in the output functions can be controlled provided that the signal to noise ratios in the original astrophysical maps are sufficiently high. The results of this paper thus increase the effectiveness of this formal system for the description, classification, and analysis of astrophysical maps.

  6. Pinch technique and the Batalin-Vilkovisky formalism

    NASA Astrophysics Data System (ADS)

    Binosi, Daniele; Papavassiliou, Joannis

    2002-07-01

    In this paper we take the first step towards a nondiagrammatic formulation of the pinch technique. In particular we proceed into a systematic identification of the parts of the one-loop and two-loop Feynman diagrams that are exchanged during the pinching process in terms of unphysical ghost Green's functions; the latter appear in the standard Slavnov-Taylor identity satisfied by the tree-level and one-loop three-gluon vertex. This identification allows for the consistent generalization of the intrinsic pinch technique to two loops, through the collective treatment of entire sets of diagrams, instead of the laborious algebraic manipulation of individual graphs, and sets up the stage for the generalization of the method to all orders. We show that the task of comparing the effective Green's functions obtained by the pinch technique with those computed in the background field method Feynman gauge is significantly facilitated when employing the powerful quantization framework of Batalin and Vilkovisky. This formalism allows for the derivation of a set of useful nonlinear identities, which express the background field method Green's functions in terms of the conventional (quantum) ones and auxiliary Green's functions involving the background source and the gluonic antifield; these latter Green's functions are subsequently related by means of a Schwinger-Dyson type of equation to the ghost Green's functions appearing in the aforementioned Slavnov-Taylor identity.

  7. Formal nomenclature and description of cryptic species of the Encyrtus sasakii complex (Hymenoptera: Encyrtidae)

    PubMed Central

    Wang, Ying; Zhou, Qing-Song; Qiao, Hui-Jie; Zhang, Ai-Bing; Yu, Fang; Wang, Xu-Bo; Zhu, Chao-Dong; Zhang, Yan-Zhou

    2016-01-01

    With the recent development of molecular approaches to species delimitation, a growing number of cryptic species have been discovered in what had previously been thought to be single morpho-species. Molecular methods, such as DNA barcoding, have greatly enhanced our knowledge of taxonomy, but taxonomy remains incomplete and needs a formal species nomenclature and description to facilitate its use in other scientific fields. A previous study using DNA barcoding, geometric morphometrics and mating tests revealed at least two cryptic species in the Encyrtus sasakii complex. (Hymenoptera: Encyrtidae). To describe these two new species formally (Encyrtus eulecaniumiae sp. nov. and Encyrtus rhodococcusiae sp. nov.), a detailed morphometric study of Encyrtus spp. was performed in addition to the molecular analysis and evaluation of biological data. Morphometric analyses, a multivariate ratio analysis (MRA) and a geometric morphometric analysis (GMA) revealed a great number of differences between the species, but reliable characteristics were not observed for diagnosing the cryptic species. We thus diagnosed these three Encyrtus species on the basis of the characteristics that resulted from genetic markers (mitochondrial cytochrome c oxidase subunit I and nuclear 28S rRNA) and biological data. A formal nomenclature and description of cryptic species was provided on the basis of an integrated taxonomy. PMID:27698441

  8. Formal description of the jumpstart just-in-time signaling protocol using EFSM

    NASA Astrophysics Data System (ADS)

    Zaim, A. H.; Baldine, Ilia; Cassada, Mark; Rouskas, George N.; Perros, Harry G.; Stevenson, Daniel S.

    2002-07-01

    We present a formal protocol description for a Just-In-Time (JIT) signaling scheme running over a core dWDM network which utilizes Optical Burst Switches (OBS). We apply an eight-tuple extended finite state machine (EFSM) model to formally specify the protocol. Using the EFSM model, we define the communication between a source client node and a destination client node through an ingress and one or multiple intermediate switches. We worked on single burst connections that means setting up the connection just before sending a single burst and then closing the connection as soon as the burst is sent. The communication between the EFSMs is handled through message transfer between protocol entities.

  9. Experience with Formal Methods techniques at the Jet Propulsion Laboratory from a quality assurance perspective

    NASA Technical Reports Server (NTRS)

    Kelly, John C.; Covington, Rick

    1993-01-01

    Recent experience with Formal Methods (FM) in the Software Quality Assurance Section at the Jet Propulsion Lab is presented. An integrated Formal Method process is presented to show how related existing requirements analysis and FM techniques complement one another. Example application of FM techniques such as formal specifications and specification animators are presented. The authors suggest that the quality assurance organization is a natural home for the Formal Methods specialist, whose expertise can then be used to best advantage across a range of projects.

  10. Retrieval from a large, integrated HIS-database through formal descriptions and SQL.

    PubMed

    Hooymans, M P; Liefkes, H; Schipper, J A; Bakker, A R

    1995-01-01

    This paper outlines the realization of rich retrieval facilities and comprehensive data administration in an existing, large, integrated Hospital Information System (HIS) using SQL as a query-language and using a large collection of formal data descriptions stored in the Data Dictionary and Directory System (DD/DS). It is emphasized that the approach to enhance the access to the database is more important than the technology. Nevertheless, the facilities are presented that support non-routine retrieval. The Data Dictionary and Directory System functions as a catalog of the information system. The vehicle that facilitates the communication with the database is an implementation of SQL-in a number of appearances. It is stressed that only full benefit can be gained through a combined action of a large integrated HIS, a complete and correct DD/DS, and strong retrieval functions.

  11. Research in advanced formal theorem-proving techniques

    NASA Technical Reports Server (NTRS)

    Rulifson, J. F.

    1971-01-01

    The present status is summarized of a continuing research program aimed at the design and implementation of a language for expressing problem-solving procedures in several areas of artificial intelligence, including program synthesis, robot planning, and theorem proving. Notations, concepts, and procedures common to the representation and solution of many of these problems were abstracted and incorporated as features into the language. The areas of research covered are described, and abstracts of six papers that contain extensive description and technical detail of the work are presented.

  12. Nursing students' reading and English aptitudes and their relationship to discipline-specific formal writing ability: a descriptive correlational study.

    PubMed

    Newton, Sarah; Moore, Gary

    2010-01-01

    Formal writing assignments are commonly used in nursing education to develop students' critical thinking skills, as well as to enhance their communication abilities. However, writing apprehension is a common phenomenon among nursing students. It has been suggested that reading and English aptitudes are related to formal writing ability, yet neither the reading nor the English aptitudes of undergraduate nursing students have been described in the literature, and the relationships that reading and English aptitude have with formal writing ability have not been explored. The purpose of this descriptive correlational study was to describe writing apprehension and to assess the relationships among reading and English aptitude and discipline-specific formal writing ability among undergraduate nursing students. The study sample consisted of 146 sophomores from one baccalaureate nursing program. The results indicated that both reading and English aptitude were related to students' formal writing ability.

  13. New modes of particle accelerations techniques and sources. Formal report

    SciTech Connect

    Parsa, Z.

    1996-12-31

    This Report includes copies of transparencies and notes from the presentations made at the Symposium on New Modes of Particle Accelerations - Techniques and Sources, August 19-23, 1996 at the Institute for Theoretical Physics, University of California, Santa Barbara California, that was made available by the authors. Editing, reduction and changes to the authors contributions were made only to fulfill the printing and publication requirements. We would like to take this opportunity and thank the speakers for their informative presentations and for providing copies of their transparencies and notes for inclusion in this Report.

  14. V and V of Lexical, Syntactic and Semantic Properties for Interactive Systems Through Model Checking of Formal Description of Dialog

    NASA Technical Reports Server (NTRS)

    Brat, Guillaume P.; Martinie, Celia; Palanque, Philippe

    2013-01-01

    During early phases of the development of an interactive system, future system properties are identified (through interaction with end users in the brainstorming and prototyping phase of the application, or by other stakehold-ers) imposing requirements on the final system. They can be specific to the application under development or generic to all applications such as usability principles. Instances of specific properties include visibility of the aircraft altitude, speed… in the cockpit and the continuous possibility of disengaging the autopilot in whatever state the aircraft is. Instances of generic properties include availability of undo (for undoable functions) and availability of a progression bar for functions lasting more than four seconds. While behavioral models of interactive systems using formal description techniques provide complete and unambiguous descriptions of states and state changes, it does not provide explicit representation of the absence or presence of properties. Assessing that the system that has been built is the right system remains a challenge usually met through extensive use and acceptance tests. By the explicit representation of properties and the availability of tools to support checking these properties, it becomes possible to provide developers with means for systematic exploration of the behavioral models and assessment of the presence or absence of these properties. This paper proposes the synergistic use two tools for checking both generic and specific properties of interactive applications: Petshop and Java PathFinder. Petshop is dedicated to the description of interactive system behavior. Java PathFinder is dedicated to the runtime verification of Java applications and as an extension dedicated to User Interfaces. This approach is exemplified on a safety critical application in the area of interactive cockpits for large civil aircrafts.

  15. A description of seismic amplitude techniques

    NASA Astrophysics Data System (ADS)

    Shadlow, James

    2014-02-01

    The acquisition of seismic data is a non-invasive technique used for determining the sub surface geology. Changes in lithology and fluid fill affect the seismic wavelet. Analysing seismic data for direct hydrocarbon indicators (DHIs), such as full stack amplitude anomalies, or amplitude variation with offset (AVO), can help a seismic interpreter relate the geophysical response to real geology and, more importantly, to distinguish the presence of hydrocarbons. Inversion is another commonly used technique that attempts to tie the seismic data back to the geology. Much has been written about these techniques, and attempting to gain an understanding on the theory and application of them by reading through various journals can be quite daunting. The purpose of this paper is to briefly outline DHI analysis, including full stack amplitude anomalies, AVO and inversion and show the relationship between all three. The equations presented have been included for completeness, but the reader can pass over the mathematical detail.

  16. [Simplified defecography technique. Description and results].

    PubMed

    Berretta, O; Chaussade, S; Coquet, M; Couturier, D; Bonnin, A; Guerre, J

    1990-10-13

    Defecography is a useful paraclinical examination to explore disturbances of continence or defecation. The purpose of this study was to present a simplified defecography technique and assess its validity in subjects without defecation problems (n = 10) and in patients complaining of idiopathic chronic constipation (n = 35). The anorectal angle at rest (RAA) and when straining at stool was not significantly different in constipated patients and in controls. Defecography often gave abnormal results. Anterior rectocele was found in almost 50 percent (17/35) of constipated patients and in 20 percent (2/10) of controls (P less than 0.05). None of the patients had posterior rectocele. Persistent imprint of the puborectal muscle during straining was present in 36 percent (9/35) of constipated patients and in 10 percent (1/10) of controls (NS). The imprint was not always associated with closure of the RAA between rest and straining; this closure was never found in controls but was observed in 6 out of 17 constipated patients (35 percent; P less than 0.05). Perineal descent (PD) varied from 0.6 to 3.7 cm (mean +/- s.e.m.: 2.0 +/- 0.63 cm) in controls, as against 0.6 to 7.9 cm (mean +/- s.e.m.: 2.7 +/- 0.45 cm) in constipated patients. In 24 percent of the constipated patients PD was greater than 3.7 cm (the maximum value recorded in controls). All constipated patients with closure of the RAA during defecation had a PD of less than 1 cm, thus confirming the concept of "pelvic floor muscle hypertonia". Disorders of rectal statics are more frequent in subjects with constipation, but their significance is varied. Some abnormalities could be the cause of constipation (e.g. anismus) and others its consequence (anterior rectal prolapse, anterior rectocele, PD).

  17. Unified Description of Electron-Nucleus Scattering within the Spectral Function Formalism

    NASA Astrophysics Data System (ADS)

    Rocco, Noemi; Lovato, Alessandro; Benhar, Omar

    2016-05-01

    The formalism based on factorization and nuclear spectral functions has been generalized to treat transition matrix elements involving two-nucleon currents, whose contribution to the nuclear electromagnetic response in the transverse channel is known to be significant. We report the results of calculations of the inclusive electron-carbon cross section, showing that the inclusion of processes involving two-nucleon currents appreciably improves the agreement between theory and data in the dip region, between the quasielastic and Δ -production peaks. The relation to approaches based on the independent particle of the nucleus and the implications for the analysis of flux-integrated neutrino-nucleus cross sections are discussed.

  18. Density operator formalism for the description of coherence evolution of a homonuclear two-spin system in rotating solids.

    PubMed

    Zhou, J; Ye, C

    1994-09-01

    Based on a simple disentangling technique of the propagator, a density operator formalism is developed to describe the behavior of a homonuclear two-spin system in rotating solids. It is shown that the coherence evolutions can be characterized in terms of quaternions or a rotation matrix in a three-dimensional space; the coherence transfers between two different spins can thus be analysed well.

  19. Operator description for thermal quantum field theories on an arbitrary path in the real time formalism

    NASA Astrophysics Data System (ADS)

    Das, Ashok; Kalauni, Pushpa

    2016-06-01

    We develop an operator description, much like thermofield dynamics, for quantum field theories on a real time path with an arbitrary parameter σ (0 ≤σ ≤β ) . We point out new features which arise when σ ≠β/2 in that the Hilbert space develops a natural, modified inner product different from the standard Dirac inner product. We construct the Bogoliubov transformation which connects the doubled vacuum state at zero temperature to the thermal vacuum in this case. We obtain the thermal Green's function (propagator) for the real massive Klein-Gordon theory as an expectation value in this thermal vacuum (with a modified inner product). The factorization of the thermal Green's function follows from this analysis. We also discuss, in the main text as well as in two appendices, various other interesting features which arise in such a description.

  20. Innovative techniques for the description of reservoir heterogeneity using tracers

    SciTech Connect

    Pope, G.; Sepehrnoori, K.

    1991-09-01

    The objective of this research is to develop an advanced, innovative technique for the description of reservoir heterogeneity. This proposed method consists of using tracers in single-well backflow tests. The general idea is to make use of fluid drift in the reservoir either due to naturally occurring pressure gradients in the reservoir, or by deliberately imposed pressure gradients using adjacent injection and production wells in the same reservoir. The analytical tool that will be used to design and interpret these tests is a compositional reservoir simulator with special features added and tested specifically for this purpose. 2 refs., 5 figs.

  1. Evaluation of drug-polymer solubility curves through formal statistical analysis: comparison of preparation techniques.

    PubMed

    Knopp, Matthias Manne; Olesen, Niels Erik; Holm, Per; Löbmann, Korbinian; Holm, René; Langguth, Peter; Rades, Thomas

    2015-01-01

    In this study, the influence of the preparation technique (ball milling, spray drying, and film casting) of a supersaturated amorphous dispersion on the quality of solubility determinations of indomethacin in polyvinylpyrrolidone was investigated by means of statistical analysis. After annealing of the amorphous dispersions above the crystallization temperature for 2 h, the solubility curve was derived from the glass transition temperature of the demixed material using the Gordon-Taylor relationship and fitting with the Flory-Huggins model. The study showed that the predicted solubility from the ball-milled mixtures was not consistent with those from spray drying and film casting, indicating fundamental differences between the preparation techniques. Through formal statistical analysis, the best combination of fit to the Flory-Huggins model and reproducibility of the measurements was analyzed. Ball milling provided the best reproducibility of the three preparation techniques; however, an analysis of residuals revealed a systematic error. In contrast, film casting demonstrated a good fit to the model but poor reproducibility of the measurements. Therefore, this study recommends that techniques such as spray drying or potentially film casting (if experimental reproducibility can be improved) should be used to prepare the amorphous dispersions when performing solubility measurements of this kind.

  2. Towards a formal description of the collapse approach to the inflationary origin of the seeds of cosmic structure

    SciTech Connect

    Diez-Tejedor, Alberto; Sudarsky, Daniel E-mail: sudarsky@nucleares.unam.mx

    2012-07-01

    Inflation plays a central role in our current understanding of the universe. According to the standard viewpoint, the homogeneous and isotropic mode of the inflaton field drove an early phase of nearly exponential expansion of the universe, while the quantum fluctuations (uncertainties) of the other modes gave rise to the seeds of cosmic structure. However, if we accept that the accelerated expansion led the universe into an essentially homogeneous and isotropic space-time, with the state of all the matter fields in their vacuum (except for the zero mode of the inflaton field), we can not escape the conclusion that the state of the universe as a whole would remain always homogeneous and isotropic. It was recently proposed in [A. Perez, H. Sahlmann and D. Sudarsky, {sup O}n the quantum origin of the seeds of cosmic structure{sup ,} Class. Quant. Grav. 23 (2006) 2317–2354] that a collapse (representing physics beyond the established paradigm, and presumably associated with a quantum-gravity effect à la Penrose) of the state function of the inflaton field might be the missing element, and thus would be responsible for the emergence of the primordial inhomogeneities. Here we will discuss a formalism that relies strongly on quantum field theory on curved space-times, and within which we can implement a detailed description of such a process. The picture that emerges clarifies many aspects of the problem, and is conceptually quite transparent. Nonetheless, we will find that the results lead us to argue that the resulting picture is not fully compatible with a purely geometric description of space-time.

  3. Bayesian Minimum Description Length Techniques for Multiple Changepoint Detection

    NASA Astrophysics Data System (ADS)

    Anuradha Priyadarshani, Hewa Arachchige

    This dissertation develops a minimum description length (MDL) multiple changepoint detection procedure that allows for prior distributions. MDL methods, which are penalized likelihood techniques with penalties based on data description-length information principles, have been successfully applied to many recent multiple changepoint problems. This work shows how to modify the MDL penalty to account for various prior knowledge. Our motivation lies in climatology. Here, a metadata record, which is a file listing times when a recording station physically moved, instrumentation was changed, etc., sometimes exists. While metadata records are notoriously incomplete, they permit the construct a prior distribution that helps detect changepoints. This allows both documented and undocumented changepoints to be analyzed in tandem. The method developed here takes into account 1) metadata, 2) reference series, 3) seasonal means, and 4) autocorrelations. Asymptotically, our estimated multiple changepoint configuration of monthly data is shown to be consistent. The methods are illustrated in the analysis of 114 years of monthly temperatures from Tuscaloosa, Alabama. The multivariate aspect of the methods allow maximum and minimum temperatures to be jointly studied. A method for homogenizing daily temperature series is also developed. While daily temperatures have a complex structure, statistical techniques have been accumulating that can now accommodate all of the salient characteristics of daily temperatures. The goal here is to combine these techniques in a reasonable manner for multiple changepoint identification in daily series; computational speed is key as a century of daily data has over 36,000 data points. Autocorrelation aspects are important since correlation can destroy changepoint techniques and sample correlations of day-to-day temperature anomalies are often as large as 0.7. While homogenized daily temperatures may not be as useful as homogenized monthly or yearly

  4. Formalisms for user interface specification and design

    NASA Technical Reports Server (NTRS)

    Auernheimer, Brent J.

    1989-01-01

    The application of formal methods to the specification and design of human-computer interfaces is described. A broad outline of human-computer interface problems, a description of the field of cognitive engineering and two relevant research results, the appropriateness of formal specification techniques, and potential NASA application areas are described.

  5. Neural Systems Language: A Formal Modeling Language for the Systematic Description, Unambiguous Communication, and Automated Digital Curation of Neural Connectivity

    PubMed Central

    Brown, Ramsay A.; Swanson, Larry W.

    2014-01-01

    Systematic description and the unambiguous communication of findings and models remain among the unresolved fundamental challenges in systems neuroscience. No common descriptive frameworks exist to describe systematically the connective architecture of the nervous system, even at the grossest level of observation. Furthermore, the accelerating volume of novel data generated on neural connectivity outpaces the rate at which this data is curated into neuroinformatics databases to synthesize digitally systems-level insights from disjointed reports and observations. To help address these challenges, we propose the Neural Systems Language (NSyL). NSyL is a modeling language to be used by investigators to encode and communicate systematically reports of neural connectivity from neuroanatomy and brain imaging. NSyL engenders systematic description and communication of connectivity irrespective of the animal taxon described, experimental or observational technique implemented, or nomenclature referenced. As a language, NSyL is internally consistent, concise, and comprehensible to both humans and computers. NSyL is a promising development for systematizing the representation of neural architecture, effectively managing the increasing volume of data on neural connectivity and streamlining systems neuroscience research. Here we present similar precedent systems, how NSyL extends existing frameworks, and the reasoning behind NSyL’s development. We explore NSyL’s potential for balancing robustness and consistency in representation by encoding previously reported assertions of connectivity from the literature as examples. Finally, we propose and discuss the implications of a framework for how NSyL will be digitally implemented in the future to streamline curation of experimental results and bridge the gaps among anatomists, imagers, and neuroinformatics databases. PMID:23787962

  6. Neural systems language: a formal modeling language for the systematic description, unambiguous communication, and automated digital curation of neural connectivity.

    PubMed

    Brown, Ramsay A; Swanson, Larry W

    2013-09-01

    Systematic description and the unambiguous communication of findings and models remain among the unresolved fundamental challenges in systems neuroscience. No common descriptive frameworks exist to describe systematically the connective architecture of the nervous system, even at the grossest level of observation. Furthermore, the accelerating volume of novel data generated on neural connectivity outpaces the rate at which this data is curated into neuroinformatics databases to synthesize digitally systems-level insights from disjointed reports and observations. To help address these challenges, we propose the Neural Systems Language (NSyL). NSyL is a modeling language to be used by investigators to encode and communicate systematically reports of neural connectivity from neuroanatomy and brain imaging. NSyL engenders systematic description and communication of connectivity irrespective of the animal taxon described, experimental or observational technique implemented, or nomenclature referenced. As a language, NSyL is internally consistent, concise, and comprehensible to both humans and computers. NSyL is a promising development for systematizing the representation of neural architecture, effectively managing the increasing volume of data on neural connectivity and streamlining systems neuroscience research. Here we present similar precedent systems, how NSyL extends existing frameworks, and the reasoning behind NSyL's development. We explore NSyL's potential for balancing robustness and consistency in representation by encoding previously reported assertions of connectivity from the literature as examples. Finally, we propose and discuss the implications of a framework for how NSyL will be digitally implemented in the future to streamline curation of experimental results and bridge the gaps among anatomists, imagers, and neuroinformatics databases.

  7. Mapping of Primary Instructional Methods and Teaching Techniques for Regularly Scheduled, Formal Teaching Sessions in an Anesthesia Residency Program.

    PubMed

    Vested Madsen, Matias; Macario, Alex; Yamamoto, Satoshi; Tanaka, Pedro

    2016-06-01

    In this study, we examined the regularly scheduled, formal teaching sessions in a single anesthesiology residency program to (1) map the most common primary instructional methods, (2) map the use of 10 known teaching techniques, and (3) assess if residents scored sessions that incorporated active learning as higher quality than sessions with little or no verbal interaction between teacher and learner. A modified Delphi process was used to identify useful teaching techniques. A representative sample of each of the formal teaching session types was mapped, and residents anonymously completed a 5-question written survey rating the session. The most common primary instructional methods were computer slides-based classroom lectures (66%), workshops (15%), simulations (5%), and journal club (5%). The number of teaching techniques used per formal teaching session averaged 5.31 (SD, 1.92; median, 5; range, 0-9). Clinical applicability (85%) and attention grabbers (85%) were the 2 most common teaching techniques. Thirty-eight percent of the sessions defined learning objectives, and one-third of sessions engaged in active learning. The overall survey response rate equaled 42%, and passive sessions had a mean score of 8.44 (range, 5-10; median, 9; SD, 1.2) compared with a mean score of 8.63 (range, 5-10; median, 9; SD, 1.1) for active sessions (P = 0.63). Slides-based classroom lectures were the most common instructional method, and faculty used an average of 5 known teaching techniques per formal teaching session. The overall education scores of the sessions as rated by the residents were high.

  8. Formal and informal organizational activities of people who inject drugs in New York City: description and correlates.

    PubMed

    Friedman, Samuel R; Pouget, Enrique R; Sandoval, Milagros; Jones, Yolanda; Mateu-Gelabert, Pedro

    2015-01-01

    Little is known about group memberships of people who inject drugs (PWID). Three hundred PWID were interviewed about formal and informal group participation and risk behaviors. Many took part in groups related to problems and resources associated with injecting drugs, religion, sports or gender. Harm reduction group and support group participation was associated with less risk behavior; sports groups participation with more risk behavior. Group involvement by PWID may be important to their lives and/or affect prevention or infectious disease transmission. More research is needed about determinants and consequences of their and other drug users' group memberships.

  9. Formal and informal organizational activities of people who inject drugs in New York City: Description and correlates

    PubMed Central

    Friedman, Samuel R.; Pouget, Enrique R.; Sandoval, Milagros; Jones, Yolanda; Mateu-Gelabert, Pedro

    2014-01-01

    Background Little is known about group memberships of people who inject drugs. Methods We interviewed 300 injectors about formal and informal group participation and risk behaviors. Results Many took part in groups related to problems and resources associated with injecting drugs, religion, sports or gender. Harm reduction group and support group participation was associated with less risk behavior; sports groups participation with more risk behavior. Discussion Group involvement by people who inject drugs may be important to their lives and/or affect prevention or infectious disease transmission. More research is needed about determinants and consequences of their and other drug users’ group memberships. PMID:25774744

  10. A two-column formalism for time-dependent modelling of stellar convection. I. Description of the method

    NASA Astrophysics Data System (ADS)

    Stökl, A.

    2008-11-01

    Context: In spite of all the advances in multi-dimensional hydrodynamics, investigations of stellar evolution and stellar pulsations still depend on one-dimensional computations. This paper devises an alternative to the mixing-length theory or turbulence models usually adopted in modelling convective transport in such studies. Aims: The present work attempts to develop a time-dependent description of convection, which reflects the essential physics of convection and that is only moderately dependent on numerical parameters and far less time consuming than existing multi-dimensional hydrodynamics computations. Methods: Assuming that the most extensive convective patterns generate the majority of convective transport, the convective velocity field is described using two parallel, radial columns to represent up- and downstream flows. Horizontal exchange, in the form of fluid flow and radiation, over their connecting interface couples the two columns and allows a simple circulating motion. The main parameters of this convective description have straightforward geometrical meanings, namely the diameter of the columns (corresponding to the size of the convective cells) and the ratio of the cross-section between up- and downdrafts. For this geometrical setup, the time-dependent solution of the equations of radiation hydrodynamics is computed from an implicit scheme that has the advantage of being unaffected by the Courant-Friedrichs-Lewy time-step limit. This implementation is part of the TAPIR-Code (short for The adaptive, implicit RHD-Code). Results: To demonstrate the approach, results for convection zones in Cepheids are presented. The convective energy transport and convective velocities agree with expectations for Cepheids and the scheme reproduces both the kinetic energy flux and convective overshoot. A study of the parameter influence shows that the type of solution derived for these stars is in fact fairly robust with respect to the constitutive numerical

  11. A Qualitative Description of Women’s HIV Self-Management Techniques: Context, Strategies, and Considerations

    PubMed Central

    Webel, Allison R.; Dolansky, Mary A.; Henry, Anna G.; Salata, Robert A.

    2011-01-01

    Women living with HIV face unique challenges managing their disease. The purpose of this descriptive, qualitative study was to describe self-management techniques reported by 48 women living with HIV in the United States. Participants were involved in one, 90-minute, digitally-recorded focus group exploring aspects of HIV self-management strategies. Descriptive statistics, qualitative description, and content analysis were used to analyze the data. Participants had been living with HIV for an average of 12 years, most (69%) were engaged in routine HIV care (85%) and were currently prescribed antiretroviral therapy. Participants reported using self-management techniques: taking personal time (n = 23; 48%), advocacy (n = 12; 25%), sleeping (n = 17, 35%); attending support groups (n = 10; 21%), and attending medical appointments (n = 8; 17%). Nurses can add strategies to enhance HIV self-management to routine clinical care, which may have a positive impact on the health of women living with HIV. PMID:22079674

  12. The Effect of Cooperative Integrated Reading and Composition Technique on Students' Reading Descriptive Text Achievement

    ERIC Educational Resources Information Center

    Zainuddin

    2015-01-01

    This study was aimed at finding out the effectiveness of applying Cooperative Integrated Reading and Composition (CIRC) Technique on Students' Reading Descriptive Text Achievement. In other words, the objective of this study was to find out if there was a significant effect of applying Cooperative Integrated Reading and Composition (CIRC)…

  13. The 'Embowire' Technique: Concept and Description of a Novel Embolization Technique for Narrow Vessels

    SciTech Connect

    Lopez-Benitez, Ruben Rusch, Oliver Heverhagen, Johannes Levent, Kara Hanno, Hoppe Geiser, Christa Kettenbach, Joachim

    2013-10-15

    We describe a new, useful embolization technique applied to occlude narrow vessel branches ({<=}1.5 mm (0.06 Double-Prime ) in diameter) by deployment of one hydrocoil, through a microcatheter, in a way similar to the way in which one might navigate through the vascular lumen with a guidewire.

  14. Geometry and Formal Linguistics.

    ERIC Educational Resources Information Center

    Huff, George A.

    This paper presents a method of encoding geometric line-drawings in a way which allows sets of such drawings to be interpreted as formal languages. A characterization of certain geometric predicates in terms of their properties as languages is obtained, and techniques usually associated with generative grammars and formal automata are then applied…

  15. The Functional Anaesthetic Discogram: Description of a Novel Diagnostic Technique and Report of 3 Cases

    PubMed Central

    Malek, Farbod; Carragee, Eugene; Kim, Mi-Jung

    2008-01-01

    Background The diagnostic evaluation of patients with presumed discogenic low back pain is controversial; recent studies have brought the specificity of the traditional technique, provocative lumbar discography, into question. One of the explanations for the relative lack of predictability in treatment outcomes for patients with discogenic low back pain may be a corresponding lack of certainty in the diagnosis. Purpose A new diagnostic technique is described for the evaluation of patients with presumptive discogenic low back pain; the cases of 3 patients in whom the technique was used are presented. Study Design/Setting Case report; university practice. Methods A technique is described in which an anaesthetic catheter is placed into putative symptomatic lumbar discs, the patient elicits his or her typical pain via a position or activity, and anaesthetic or placebo is delivered to the disc. The effect of the injected substance on the patient's pain is then noted. Results In one patient, the new test was confirmatory of the results of the provocative discogram; in two patients, the test results were divergent. Conclusions These case studies and technical description are presented as a first step in examining this method of preoperative assessment. Further study of the technique will allow us to make more definitive recommendations with regards to its validity and utility. Level of Evidence Level 4 – Case Series PMID:25802610

  16. Recommended procedures and techniques for the petrographic description of bituminous coals

    USGS Publications Warehouse

    Chao, E.C.T.; Minkin, J.A.; Thompson, C.L.

    1982-01-01

    bed. The use of bulk-specific-gravity determinations is alo recommended for identification and characterization of the distinctive lithologic units. The availability of an AIAS also enhances the capability to acquire textural information. Ranges of size of maceral and mineral grains can be quickly and precisely determined by use of an AIAS. We assume that shape characteristics of coal particles can also be readily evaluated by automated image analysis, although this evaluation has not yet been attempted in our laboratory. Definitive data on the particulate mineral content of coal constitute another important segment of petrographic description. Characterization of mineral content may be accomplished by optical identification, electron microprobe analysis, X-ray diffraction, and scanning and transmission electron microscopy. Individual mineral grains in place in polished blocks or polished this sections, or separated from the coal matrix by sink-float methods are studied by analytical techniques appropriate to the conditions of sampling. Finally, whenever possible, identification of the probable genus or plant species from which a given coal component is derived will add valuable information and meaning to the petrographic description. ?? 1982.

  17. Practical Issues with Formal Specifications

    NASA Astrophysics Data System (ADS)

    Altenhofen, Michael; Brucker, Achim D.

    Many software companies still seem to be reluctant to use formal specifications in their development processes. Nevertheless, the trend towards implementing critical business applications in distributed environments makes such applications an attractive target for formal methods. Additionally, the rising complexity also increases the willingness of the development teams to apply formal techniques.

  18. Formalizing Space Shuttle Software Requirements

    NASA Technical Reports Server (NTRS)

    Crow, Judith; DiVito, Ben L.

    1996-01-01

    This paper describes two case studies in which requirements for new flight-software subsystems on NASA's Space Shuttle were analyzed, one using standard formal specification techniques, the other using state exploration. These applications serve to illustrate three main theses: (1) formal methods can complement conventional requirements analysis processes effectively, (2) formal methods confer benefits regardless of how extensively they are adopted and applied, and (3) formal methods are most effective when they are judiciously tailored to the application.

  19. Formalizing Probabilistic Safety Claims

    NASA Technical Reports Server (NTRS)

    Herencia-Zapana, Heber; Hagen, George E.; Narkawicz, Anthony J.

    2011-01-01

    A safety claim for a system is a statement that the system, which is subject to hazardous conditions, satisfies a given set of properties. Following work by John Rushby and Bev Littlewood, this paper presents a mathematical framework that can be used to state and formally prove probabilistic safety claims. It also enables hazardous conditions, their uncertainties, and their interactions to be integrated into the safety claim. This framework provides a formal description of the probabilistic composition of an arbitrary number of hazardous conditions and their effects on system behavior. An example is given of a probabilistic safety claim for a conflict detection algorithm for aircraft in a 2D airspace. The motivation for developing this mathematical framework is that it can be used in an automated theorem prover to formally verify safety claims.

  20. Limb lengthening with submuscular plate stabilization: a case series and description of the technique.

    PubMed

    Iobst, Christopher A; Dahl, Mark T

    2007-01-01

    Combining a circular fixator with a percutaneously inserted locking plate has all of the same advantages that lengthening over an intramedullary nail provides but eliminates the concern with regard to creating a deep infection in the medullary canal. It also can be applied to virtually any bone in any age group of patients without any concern with regard to causing avascular necrosis, fat embolism, or physeal injury. The design of the locking plate prevents loss of fixation and protects against bending of the regenerate bone after frame removal. This study represents a description of the surgical technique and a retrospective examination of the first 6 patients treated using this technique. The average age of the patients is 7.6 years, and the average duration of follow-up is 10 months. All 6 patients achieved solid union of the lengthening site and full, unassisted weight bearing with excellent range of motion. The mean lengthening was 3.52 cm, which represents an average of 14.6% of the overall bone length. The mean duration of external fixation was 45 days, and the mean external fixation index was 0.42 mo/cm. The mean distraction rate was 0.85 mm/d. There were 3 serious and 2 severe complications noted. The serious complications included the development of a premature consolidation and a translational deformity of the regenerate in 1 patient, requiring a revision corticotomy, and a fall of a second patient 3 months after fixator removal, causing a fracture at the superior edge of his locking plate. The 2 severe complications were an 11-degree and an 18-degree residual procurvatum deformity that developed during lengthening. In conclusion, lengthening with the assistance of a percutaneously inserted locking plate provides an alternative method to lengthening over an intramedullary nail, applicable to children with open physes.

  1. [A formal description of mammals' behavior based on data on snow tracking, with pine marten (Martes martes) as a case study].

    PubMed

    Vladimirova, É D; Morozov, V V

    2014-01-01

    The formalism allowing to describe animals' behavior is based on the model of informational interactions between an animal and its environment. The model may be represented as an assemblage consisting of two blocks. The first block, which corresponds to the perception system, is a probabilistic operator: it selects an object of certain class out of many objects randomly encountered by an animal while it moves around. The selected object keeps its actuality as an input symbol for the second block of the assemblage during one or several cycles of the block operation. The second block, being afinite structural probabilistic automaton, generates output reactions to the input symbol. The structural automaton, which consists of elementary automata, produces a sequence of output reactions in course of interactions with the selected object: After exhaustion of the previous input actuality, the assemblage moves to the next cycle. At that, the probabilistic operator comes back to the receptive state and produces next output. Automaton "inputs" correspond to objects of certain classes, selectively perceived by an animal; "outputs" correspond to a sequence of elementary motor reactions. Based on data on snow tracking of pine marten foraging activity, there have been composed: the assemblage input and output alphabets, a conjugation matrix of input signals and internal states of the first elementary automaton that is contained in the second block structure, and transition probability matrices for the states of the second block elementary automata, which are defined for a class of environmental objects when foraging activity occurs. The proposed formalism makes it possible to convert field data on tracking into the unified form, detect key circumstances of animals' behavioral activity, and analyze this natural phenomenon in detail.

  2. Rethinking Formalisms in Formal Education

    ERIC Educational Resources Information Center

    Nathan, Mitchell J.

    2012-01-01

    I explore a belief about learning and teaching that is commonly held in education and society at large that nonetheless is deeply flawed. The belief asserts that mastery of "formalisms"--specialized representations such as symbolic equations and diagrams with no inherent meaning except that which is established by convention--is prerequisite to…

  3. Beyond formalism

    NASA Technical Reports Server (NTRS)

    Denning, Peter J.

    1991-01-01

    The ongoing debate over the role of formalism and formal specifications in software features many speakers with diverse positions. Yet, in the end, they share the conviction that the requirements of a software system can be unambiguously specified, that acceptable software is a product demonstrably meeting the specifications, and that the design process can be carried out with little interaction between designers and users once the specification has been agreed to. This conviction is part of a larger paradigm prevalent in American management thinking, which holds that organizations are systems that can be precisely specified and optimized. This paradigm, which traces historically to the works of Frederick Taylor in the early 1900s, is no longer sufficient for organizations and software systems today. In the domain of software, a new paradigm, called user-centered design, overcomes the limitations of pure formalism. Pioneered in Scandinavia, user-centered design is spreading through Europe and is beginning to make its way into the U.S.

  4. Young Children's Descriptions of Their Local Environment: A Comparison of Information Elicited by Recall Recognition and Performance Techniques of Investigation.

    ERIC Educational Resources Information Center

    Spencer, Christopher; Darvizeh, Zhra

    1981-01-01

    Results are reported of a study which used recall (verbal description, drawing, modelling in two and three dimensions) and recognition (photograph) techniques to determine three- and four-year-olds' knowledge of routes in their local environment and their ability to express this knowledge. (DC)

  5. Academic Staff's Apathy towards Formal Professional Development Programmes at North West University

    ERIC Educational Resources Information Center

    Makunye, M. M.; Pelser, T. G.

    2012-01-01

    The purpose of this study was to explore reasons for academics' apathy towards formal professional development programmes at North-West University. The research design was essentially descriptive, employing both qualitative and quantitative research techniques to gather and analyse data. Three techniques, namely, questionnaire surveys, analysis of…

  6. Line group techniques in description of the structural phase transitions in some superconductors

    NASA Technical Reports Server (NTRS)

    Meszaros, CS.; Balint, A.; Bankuti, J.

    1995-01-01

    The main features of the theory of line groups, and their irreducible representations are briefly discussed, as well as the most important applications of them. A new approach in the general symmetry analysis of the modulated systems is presented. It is shown, that the line group formalism could be a very effective tool in the examination of the structural phase transitions in High Temperature SUperconductors. As an example, the material YBa2Cu3O(7-x) is discussed briefly.

  7. Formal verification of AI software

    NASA Technical Reports Server (NTRS)

    Rushby, John; Whitehurst, R. Alan

    1989-01-01

    The application of formal verification techniques to Artificial Intelligence (AI) software, particularly expert systems, is investigated. Constraint satisfaction and model inversion are identified as two formal specification paradigms for different classes of expert systems. A formal definition of consistency is developed, and the notion of approximate semantics is introduced. Examples are given of how these ideas can be applied in both declarative and imperative forms.

  8. Line group techniques in description of the structural phase transitions in some superconductors

    SciTech Connect

    Meszaros, C.; Bankuti, J.; Balint, A.

    1994-12-31

    The main features of the theory of line groups, and their irreducible representations are briefly discussed, as well as the most important applications of them. A new approach in the general symmetry analysis of the modulated systems is presented. It is shown, that the line group formalism could be a very effective tool in the examination of the structural phase transitions in High Temperature Superconductors. As an example, the material YBa{sub 2}Cu{sub 3}O{sub 7-x} is discussed briefly.

  9. Per Oral Endoscopic Myotomy for Achalasia: A Detailed Description of the Technique and Review of the Literature.

    PubMed

    Grimes, Kevin L; Inoue, Haruhiro

    2016-05-01

    Historically, the most robust outcomes in treatment of achalasia were seen with surgical myotomy. Per oral endoscopic myotomy (POEM) introduced an endoscopic method for creating a surgical myotomy. Thousands of cases of POEM have been performed; however, there is no standard technique, and the rates of clinical success and adverse events vary widely among centers. This article presents a detailed description of the POEM technique, including the rationale and potential pitfalls of the main variations, in the context of the international literature. PMID:27112254

  10. Description of a novel technique for suture ligation of the renal vessels during robotic nephrectomy.

    PubMed

    Patel, Manish N; Laungani, Rajesh; Shrivastava, Alok; Bhandari, Akshay; Spencer Krane, L; Menon, Mani; Rogers, Craig G

    2009-03-01

    Minimally invasive techniques are frequently used for surgical treatment of suspected malignant renal masses. We previously reported on our experience with robotic nephrectomy and the feasibility of performing suture ligation of the renal vessels using robotic needle drivers. We describe a novel technique for suture ligation of the renal vessels during robotic nephrectomy utilizing the robotic hook and a suture with loops at each end. Our technique for suture ligation of the renal vessels recapitulates the open technique without the need for exchanging the robotic working instruments for robotic needle drivers and without the need for endovascular staplers. PMID:27628449

  11. A descriptive analysis of batting backlift techniques in cricket: Does the practice of elite cricketers follow the theory?

    PubMed

    Noorbhai, M Habib; Noakes, Timothy D

    2016-10-01

    One of the first principles of cricket batsmanship that is coached from a young age is to play with a straight bat. Limited studies to date have examined whether top international batsmen use this traditionally described technique. Accordingly, we performed a descriptive, observational study of the backlift technique adopted by 65 of the most successful batsmen of all time, based on their career averages, strike rate and runs scored. The batsmen were divided into two groups depending on whether they played the game before or after 1954. Surprisingly, more than 70% of these successful batsmen did not adopt the traditionally taught technique. Instead, they adopted a more looped action in which the initial movement of the bat was in the direction of the slips, and in extreme cases it was either towards the gully/point region or to have the face of the bat directed towards the off-side. This suggests that traditionally taught batting coaching techniques may hinder, rather than enhance future cricketing performance. Since the vast majority of cricketers are not coached in this technique, this finding probably indicates that this looped technique is likely a contributing factor to effective batsmanship.

  12. A descriptive analysis of batting backlift techniques in cricket: Does the practice of elite cricketers follow the theory?

    PubMed

    Noorbhai, M Habib; Noakes, Timothy D

    2016-10-01

    One of the first principles of cricket batsmanship that is coached from a young age is to play with a straight bat. Limited studies to date have examined whether top international batsmen use this traditionally described technique. Accordingly, we performed a descriptive, observational study of the backlift technique adopted by 65 of the most successful batsmen of all time, based on their career averages, strike rate and runs scored. The batsmen were divided into two groups depending on whether they played the game before or after 1954. Surprisingly, more than 70% of these successful batsmen did not adopt the traditionally taught technique. Instead, they adopted a more looped action in which the initial movement of the bat was in the direction of the slips, and in extreme cases it was either towards the gully/point region or to have the face of the bat directed towards the off-side. This suggests that traditionally taught batting coaching techniques may hinder, rather than enhance future cricketing performance. Since the vast majority of cricketers are not coached in this technique, this finding probably indicates that this looped technique is likely a contributing factor to effective batsmanship. PMID:26956380

  13. Monitoring of Land Subsidence in Ravenna Municipality Using Integrated SAR - GPS Techniques: Description and First Results

    NASA Astrophysics Data System (ADS)

    Artese, G.; Fiaschi, S.; Di Martire, D.; Tessitore, S.; Fabris, M.; Achilli, V.; Ahmed, A.; Borgstrom, S.; Calcaterra, D.; Ramondini, M.; Artese, S.; Floris, M.; Menin, A.; Monego, M.; Siniscalchi, V.

    2016-06-01

    The Emilia Romagna Region (N-E Italy) and in particular the Adriatic Sea coastline of Ravenna, is affected by a noticeable subsidence that started in the 1950s, when the exploitation of on and off-shore methane reservoirs began, along with the pumping of groundwater for industrial uses. In such area the current subsidence rate, even if lower than in the past, reaches the -2 cm/y. Over the years, local Authorities have monitored this phenomenon with different techniques: spirit levelling, GPS surveys and, more recently, Differential Interferometric Synthetic Aperture Radar (DInSAR) techniques, confirming the critical situation of land subsidence risk. In this work, we present the comparison between the results obtained with DInSAR and GPS techniques applied to the study of the land subsidence in the Ravenna territory. With regard to the DInSAR, the Small Baseline Subset (SBAS) and the Coherent Pixel Technique (CPT) techniques have been used. Different SAR datasets have been exploited: ERS-1/2, ENVISAT, TerraSAR-X and Sentinel-1. Some GPS campaigns have been also carried out in a subsidence prone area. 3D vertices have been selected very close to existing persistent scatterers in order to link the GPS measurement results to the SAR ones. GPS data were processed into the International reference system and the comparisons between the coordinates, for the first 6 months of the monitoring, provided results with the same trend of the DInSAR data, even if inside the precision of the method.

  14. Chondroblastoma of the femoral head disrupting the articular cartilage. Description of a novel surgical technique.

    PubMed

    Givissis, Panagiotis; Agathangelidis, Filon; Christodoulou, Evangelos; Christodoulou, Anastasios

    2012-06-01

    Chondroblastoma is a rare benign tumour. Involvement of the femoral head may often lead to a delayed diagnosis. We present the case of a 15-year-old patient with right hip pain which was first attributed to adductor tendinitis. Following aggravation of the symptoms, thorough investigation including a CT-guided biopsy, revealed the diagnosis of chondroblastoma of the femoral head. Removal of the lesion based on the techniques described in literature was not possible, mainly because the articular cartilage was breached. A novel surgical technique was used in order to address the rare location and behaviour of the tumour. This technique offered the patient pain relief and return to his previous every day and sports activities. No recurrence was seen at two years follow-up.

  15. Chondroblastoma of the femoral head disrupting the articular cartilage. Description of a novel surgical technique.

    PubMed

    Givissis, Panagiotis; Agathangelidis, Filon; Christodoulou, Evangelos; Christodoulou, Anastasios

    2012-06-01

    Chondroblastoma is a rare benign tumour. Involvement of the femoral head may often lead to a delayed diagnosis. We present the case of a 15-year-old patient with right hip pain which was first attributed to adductor tendinitis. Following aggravation of the symptoms, thorough investigation including a CT-guided biopsy, revealed the diagnosis of chondroblastoma of the femoral head. Removal of the lesion based on the techniques described in literature was not possible, mainly because the articular cartilage was breached. A novel surgical technique was used in order to address the rare location and behaviour of the tumour. This technique offered the patient pain relief and return to his previous every day and sports activities. No recurrence was seen at two years follow-up. PMID:22822587

  16. A minimally invasive technique for percutaneous lumbar facet augmentation: Technical description of a novel device

    PubMed Central

    Smith, Zachary A.; Armin, Sean; Raphael, Dan; Khoo, Larry T.

    2011-01-01

    Background: We describe a new posterior dynamic stabilizing system that can be used to augment the mechanics of the degenerating lumbar segment. The mechanism of this system differs from other previously described surgical techniques that have been designed to augment lumbar biomechanics. The implant and technique we describe is an extension-limiting one, and it is designed to support and cushion the facet complex. Furthermore, it is inserted through an entirely percutaneous technique. The purpose of this technical note is to demonstrate a novel posterior surgical approach for the treatment of lumbar degenerative. Methods: This report describes a novel, percutaneously placed, posterior dynamic stabilization system as an alternative option to treat lumbar degenerative disk disease with and without lumbar spinal stenosis. The system does not require a midline soft-tissue dissection, nor subperiosteal dissection, and is a truly minimally invasive means for posterior augmentation of the functional facet complex. This system can be implanted as a stand-alone procedure or in conjunction with decompression procedures. Results: One-year clinical results in nine individual patients, all treated for degenerative disease of the lower lumbar spine, are presented. Conclusions: This novel technique allows for percutaneous posterior dynamic stabilization of the lumbar facet complex. The use of this procedure may allow a less invasive alternative to traditional approaches to the lumbar spine as well as an alternative to other newly developed posterior dynamic stabilization systems. PMID:22145084

  17. Formalization of algorithms for relational database machines

    SciTech Connect

    Ryvkin, V.M.; Komarov, P.I.; Nazarov, A.S.

    1986-11-01

    This paper applies the apparatus of algorithmic algebras to formalize the mapping of the relational algebra language into the internal database processor language. The apparatus is a popular tool for formal structured description of parallel algorithms. The MUL'TIPROTSESSIST automatic parallel program design system using systems of algorithmic algebras may be applied to automate the design of database machine operating algorithms in experimental research and to formalize the parallel organization of interpretation algorithms for the relational algebraic operations.

  18. Endoscopic treatment of ureterovesical junction obstructive pathology: A description of the oblique meatotomy technique and results

    PubMed Central

    Arrabal-Martín, Miguel; Zuluaga-Gómez, Armando; Merino-Salas, Sergio; Nogueras-Ocaña, Mercedes; Arrabal-Polo, Miguel Ángel

    2013-01-01

    Background: Benign obstructive pathology of the ureterovesical junction includes congenital and acquired illnesses. The objective of this study was to describe the endoscopic oblique meatotomy technique using scissors and cold cutting to treat benign obstructive pathology of the ureterovesical junction. Methods: From 2007 to 2012, we treated 18 patients with obstructive pathology of the ureterovesical junction (5 megaureters [3 with lithiasis], 4 iatrogenic stenoses, and 9 ureteroceles with lithiasis). In all cases, oblique meatotomy was performed using endoscopic scissors through an 8.5 Ch ureteroscope. The mean follow-up for all patients was 3 years. Pain, grade of hydronephrosis, and occurrence of vesicoureteral reflux were evaluated before and after treatment. Results: The mean endoscopic treatment time was 13.4 minutes. The procedure was performed on an outpatient basis with 6 hours of hospital admission, and a double J stent was inserted for 6 weeks. We achieved treatment success in 94.5% of patients after 3 years of follow-up. Only 1 patient presented with vesicoureteral reflux at 12 months after treatment; however, this condition did not require further treatment. Overall, 100% of patients remained free from lithiasis. There are 2 main limitations: the small number of patients and the lack of another group to compare the results of this technique; however, the aim of this work was to communicate a new technique to treat ureterovesical junction stricture Interpretation: Oblique ureteral meatotomy is a safe and effective treatment for benign obstructive pathology of the ureterovesical junction and has a low index of complications. PMID:24282466

  19. Dowel Fusion of the Scapho-Trapezio-Trapezoid Joint: A Description of a New Technique.

    PubMed

    Thurston; Stanley

    1999-12-01

    We describe a modification of the technique for arthrodesis of the joints between the scaphoid, the trapezoid and the trapezium (the S-T-T joint) described by Sandow, that involves the en bloc resection of a cylinder of bone incorporating a portion of each of the scaphoid, trapezoid and the trapezium, using a hollow mill, and replacing it with a cylindrical graft of exactly the same size taken from the distal radius. The procedure is relatively quick and easy with a high rate of fusion and must be regarded as a preferable alternative to other, more complex procedures.

  20. Formal Methods at Intel - An Overview

    NASA Technical Reports Server (NTRS)

    Harrison, John

    2010-01-01

    Since the 1990s, Intel has invested heavily in formal methods, which are now deployed in several domains: hardware, software, firmware, protocols etc. Many different formal methods tools and techniques are in active use, including symbolic trajectory evaluation, temporal logic model checking, SMT-style combined decision procedures, and interactive higher-order logic theorem proving. I will try to give a broad overview of some of the formal methods activities taking place at Intel, and describe the challenges of extending formal verification to new areas and of effectively using multiple formal techniques in combination

  1. Identification of Behavior Change Techniques and Engagement Strategies to Design a Smartphone App to Reduce Alcohol Consumption Using a Formal Consensus Method

    PubMed Central

    Crane, David; West, Robert; Brown, Jamie; Michie, Susan

    2015-01-01

    Background Digital interventions to reduce excessive alcohol consumption have the potential to have a broader reach and be more cost-effective than traditional brief interventions. However, there is not yet strong evidence for their ability to engage users or their effectiveness. Objective This study aimed to identify the behavior change techniques (BCTs) and engagement strategies most worthy of further study by inclusion in a smartphone app to reduce alcohol consumption, using formal expert consensus methods. Methods The first phase of the study consisted of a Delphi exercise with three rounds. It was conducted with 7 international experts in the field of alcohol and/or behavior change. In the first round, experts identified BCTs most likely to be effective at reducing alcohol consumption and strategies most likely to engage users with an app; these were rated in the second round; and those rated as effective by at least four out of seven participants were ranked in the third round. The rankings were analyzed using Kendall’s W coefficient of concordance, which indicates consensus between participants. The second phase consisted of a new, independent group of experts (n=43) ranking the BCTs that were identified in the first phase. The correlation between the rankings of the two groups was assessed using Spearman’s rank correlation coefficient. Results Twelve BCTs were identified as likely to be effective. There was moderate agreement among the experts over their ranking (W=.465, χ2 11=35.8, P<.001) and the BCTs receiving the highest mean rankings were self-monitoring, goal-setting, action planning, and feedback in relation to goals. There was a significant correlation between the ranking of the BCTs by the group of experts who identified them and a second independent group of experts (Spearman’s rho=.690, P=.01). Seventeen responses were generated for strategies likely to engage users. There was moderate agreement among experts on the ranking of these

  2. A Description of the Revised ATHEANA (A Technique for Human Event Analysis)

    SciTech Connect

    FORESTER,JOHN A.; BLEY,DENNIS C.; COOPER,SUSANE; KOLACZKOWSKI,ALAN M.; THOMPSON,CATHERINE; RAMEY-SMITH,ANN; WREATHALL,JOHN

    2000-07-18

    This paper describes the most recent version of a human reliability analysis (HRA) method called ``A Technique for Human Event Analysis'' (ATHEANA). The new version is documented in NUREG-1624, Rev. 1 [1] and reflects improvements to the method based on comments received from a peer review that was held in 1998 (see [2] for a detailed discussion of the peer review comments) and on the results of an initial trial application of the method conducted at a nuclear power plant in 1997 (see Appendix A in [3]). A summary of the more important recommendations resulting from the peer review and trial application is provided and critical and unique aspects of the revised method are discussed.

  3. Perfusion Angiography of the Foot in Patients with Critical Limb Ischemia: Description of the Technique

    SciTech Connect

    Jens, Sjoerd Marquering, Henk A.; Koelemay, Mark J. W.; Reekers, Jim A.

    2015-02-15

    ObjectiveTo study the feasibility of 2D perfusion imaging in critical limb ischemia (CLI).Methods/ResultsPerfusion angiography is a new technology which was tested in 18 patients with CLI of the foot. A standardized protocol was used with a catheter placed at the mid-part of the popliteal artery, and a total of 9 cc of non-ionic iodinated contrast material was injected at a rate of 3 cc/sec. The technology is based on early cardiology research where iodinated contrast agents were used for imaging of cardiac perfusion. During the first pass of the contrast, there is a significant diffusion of the contrast agents into the interstitial space, particularly for non-ionic and low-molecular-weight compounds.DiscussionThe original angiography data can be used to make a time–density curve, which represents the actual perfusion of the foot in time. Angiographic perfusion imaging is a post-processing modality for which no extra contrast or radiation is needed. With this technique, it is possible to get more information about the perfusion status and microcirculation of the foot. This is a step toward functional imaging in CLI patients.

  4. Management of Giant Calcified Thoracic Disks and Description of the Trench Vertebrectomy Technique

    PubMed Central

    Al-Mahfoudh, Rafid; Mitchell, Paul S.; Wilby, Martin; Crooks, Daniel; Barrett, Chris; Pillay, Robin; Pigott, Tim

    2015-01-01

    Study Design  Case series and review of the literature. Objective  To review the management of giant calcified disks in our large cohort and compare with the existing literature. We discuss our surgical technique. Methods  Twenty-nine cases of herniated thoracic disk between 2000 and 2013 were reviewed. Eighteen patients were identified as having giant calcified thoracic disks, defined as diffusely calcified disks occupying at least 40% of the spinal canal. Demographic data was collected in addition to presentation, imaging findings, operative details, and outcomes using the modified Japanese Orthopaedic Association (mJOA) scale. Results  Giant calcified thoracic disks (GCTDs) are unique clinical entities that require special neurosurgical consideration owing to significant (≥40%) involvement of the spinal canal and compression of the spinal cord, often leading to myelopathy. The median age at diagnosis was 51.2 years (range 37 to 70) with the mean duration of presenting symptoms being 9.9 months (range 2 weeks to 3 years). Seventeen (94.4%) patients presented with at least one sign of myelopathy (hyperreflexia, hypertonia, bladder or bowel dysfunction) with the remaining 1 (5.6%) patient presenting with symptoms in keeping with radiculopathy. Thoracotomy was performed on 17 (94.4%) patients, and 1 (5.6%) patient had a costotransverse approach. Mean follow-up was 19.8 months (range 7 months to 2 years). mJOA score improved in 15 (83.3%) patients. mJOA scores in the other patients remained stable. Conclusions  GCTDs are difficult neurosurgical challenges owing to their size, degree of spinal cord compression, and consistency. We recommend a trench vertebrectomy via a thoracotomy in their surgical management. This procedure safely allows the identification of normal dura on either side of the compressed segment prior to performing a diskectomy. Excellent fusion rates were achieved with insertion of rib head autograft in the trench. PMID:27556000

  5. An elementary tutorial on formal specification and verification using PVS

    NASA Technical Reports Server (NTRS)

    Butler, Ricky W.

    1993-01-01

    A tutorial on the development of a formal specification and its verification using the Prototype Verification System (PVS) is presented. The tutorial presents the formal specification and verification techniques by way of specific example - an airline reservation system. The airline reservation system is modeled as a simple state machine with two basic operations. These operations are shown to preserve a state invariant using the theorem proving capabilities of PVS. The technique of validating a specification via 'putative theorem proving' is also discussed and illustrated in detail. This paper is intended for the novice and assumes only some of the basic concepts of logic. A complete description of user inputs and the PVS output is provided and thus it can be effectively used while one is sitting at a computer terminal.

  6. Fluoroscopy-Guided Sacroiliac Joint Injection: Description of a Modified Technique.

    PubMed

    Kasliwal, Prasad Jaychand; Kasliwal, Sapana

    2016-02-01

    Sacroiliac joint (SIJ) pathology is a common etiologic cause for 10 - 27% of cases of mechanical low back pain (LBP) below the L5 level. In the absence of definite clinical or radiologic diagnostic criteria, controlled blocks of the SIJ have become the choice assessment method for making the diagnosis of SIJ pain. The SI joint is most often characterized as a large, auricular-shaped, diarthrodial synovial joint. In reality, its synovial characteristic is limited only to the distal third and anterior third. In SIJ interventions, the lateral view has been underutilized. In our technique, we used the lateral view to create a three-dimensional view of the SIJ to aid in gauging the accurateness of the contrast spread and to obtain a precise block. After obtaining appropriate fluoroscopic images, a curved tip spinal needle was directed into the inferior aspect of the SIJ using a posterior approach. As the needle contacts firm tissues on the posterior aspect of the joint, position of the needle tip is checked using lateral fluoroscopy. In the lateral view, the needle tip position is manipulated to keep it in the anterior third of the SIJ and contrast is injected. Our criteria for accurate SIJ block, in posteroanterior (PA) view, is the injection of the contrast medium should outline the joint space and the contrast medium should be seen to travel cephalad along the joint line. In the lateral view, the contrast medium most densely outlines the parameter of the joint. We have utilized this method with good effect in approximately 30 cases over one year. Out of 30 cases, needle position and contrast spread was satisfactory in 28 and 27 cases, respectively. So satisfactory needle placement and contrast spread was in 93% and 87% cases. Pain relief of 80% or more after intra-articular injection of local anesthetic was seen in 50% (15 of 30) patients; pain relief of 50 - 79% was witnessed in 30% (9 of 30) patients. Thus, pain decreased 50% or more in 80% (24 of 30) of the joints

  7. Characteristics of miniature electronic brachytherapy x-ray sources based on TG-43U1 formalism using Monte Carlo simulation techniques

    SciTech Connect

    Safigholi, Habib; Faghihi, Reza; Jashni, Somaye Karimi; Meigooni, Ali S.

    2012-04-15

    Purpose: The goal of this study is to determine a method for Monte Carlo (MC) characterization of the miniature electronic brachytherapy x-ray sources (MEBXS) and to set dosimetric parameters according to TG-43U1 formalism. TG-43U1 parameters were used to get optimal designs of MEBXS. Parameters that affect the dose distribution such as anode shapes, target thickness, target angles, and electron beam source characteristics were evaluated. Optimized MEBXS designs were obtained and used to determine radial dose functions and 2D anisotropy functions in the electron energy range of 25-80 keV. Methods: Tungsten anode material was considered in two different geometries, hemispherical and conical-hemisphere. These configurations were analyzed by the 4C MC code with several different optimization techniques. The first optimization compared target thickness layers versus electron energy. These optimized thicknesses were compared with published results by Ihsan et al.[Nucl. Instrum. Methods Phys. Res. B 264, 371-377 (2007)]. The second optimization evaluated electron source characteristics by changing the cathode shapes and electron energies. Electron sources studied included; (1) point sources, (2) uniform cylinders, and (3) nonuniform cylindrical shell geometries. The third optimization was used to assess the apex angle of the conical-hemisphere target. The goal of these optimizations was to produce 2D-dose anisotropy functions closer to unity. An overall optimized MEBXS was developed from this analysis. The results obtained from this model were compared to known characteristics of HDR {sup 125}I, LDR {sup 103}Pd, and Xoft Axxent electronic brachytherapy source (XAEBS) [Med. Phys. 33, 4020-4032 (2006)]. Results: The optimized anode thicknesses as a function of electron energy is fitted by the linear equation Y ({mu}m) = 0.0459X (keV)-0.7342. The optimized electron source geometry is obtained for a disk-shaped parallel beam (uniform cylinder) with 0.9 mm radius. The TG-43

  8. A passive microwave technique for estimating rainfall and vertical structure information from space. Part 1: Algorithm description

    NASA Technical Reports Server (NTRS)

    Kummerow, Christian; Giglio, Louis

    1994-01-01

    This paper describes a multichannel physical approach for retrieving rainfall and vertical structure information from satellite-based passive microwave observations. The algorithm makes use of statistical inversion techniques based upon theoretically calculated relations between rainfall rates and brightness temperatures. Potential errors introduced into the theoretical calculations by the unknown vertical distribution of hydrometeors are overcome by explicity accounting for diverse hydrometeor profiles. This is accomplished by allowing for a number of different vertical distributions in the theoretical brightness temperature calculations and requiring consistency between the observed and calculated brightness temperatures. This paper will focus primarily on the theoretical aspects of the retrieval algorithm, which includes a procedure used to account for inhomogeneities of the rainfall within the satellite field of view as well as a detailed description of the algorithm as it is applied over both ocean and land surfaces. The residual error between observed and calculated brightness temperatures is found to be an important quantity in assessing the uniqueness of the solution. It is further found that the residual error is a meaningful quantity that can be used to derive expected accuracies from this retrieval technique. Examples comparing the retrieved results as well as the detailed analysis of the algorithm performance under various circumstances are the subject of a companion paper.

  9. The Archival Photograph and Its Meaning: Formalisms for Modeling Images

    ERIC Educational Resources Information Center

    Benson, Allen C.

    2009-01-01

    This article explores ontological principles and their potential applications in the formal description of archival photographs. Current archival descriptive practices are reviewed and the larger question is addressed: do archivists who are engaged in describing photographs need a more formalized system of representation, or do existing encoding…

  10. Formal Methods for Life-Critical Software

    NASA Technical Reports Server (NTRS)

    Butler, Ricky W.; Johnson, Sally C.

    1993-01-01

    The use of computer software in life-critical applications, such as for civil air transports, demands the use of rigorous formal mathematical verification procedures. This paper demonstrates how to apply formal methods to the development and verification of software by leading the reader step-by-step through requirements analysis, design, implementation, and verification of an electronic phone book application. The current maturity and limitations of formal methods tools and techniques are then discussed, and a number of examples of the successful use of formal methods by industry are cited.

  11. Software Formal Inspections Guidebook

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The Software Formal Inspections Guidebook is designed to support the inspection process of software developed by and for NASA. This document provides information on how to implement a recommended and proven method for conducting formal inspections of NASA software. This Guidebook is a companion document to NASA Standard 2202-93, Software Formal Inspections Standard, approved April 1993, which provides the rules, procedures, and specific requirements for conducting software formal inspections. Application of the Formal Inspections Standard is optional to NASA program or project management. In cases where program or project management decide to use the formal inspections method, this Guidebook provides additional information on how to establish and implement the process. The goal of the formal inspections process as documented in the above-mentioned Standard and this Guidebook is to provide a framework and model for an inspection process that will enable the detection and elimination of defects as early as possible in the software life cycle. An ancillary aspect of the formal inspection process incorporates the collection and analysis of inspection data to effect continual improvement in the inspection process and the quality of the software subjected to the process.

  12. Percutaneous ultrasound-guided aspiration of an anterior cruciate ligament ganglion cyst: description of technique and case presentation.

    PubMed

    Krill, Michael; Peck, Evan

    2014-12-01

    An anterior cruciate ligament ganglion cyst is an infrequent but potentially clinically significant cause of knee pain. Although the cyst may be removed surgically, percutaneous ultrasound-guided anterior cruciate ligament ganglion cyst aspiration and injection is feasible. To our knowledge, we present the first reported case description of the utilization of ultrasound guidance to perform this procedure with a successful clinical outcome.

  13. MECHANICAL DRAFTING AND DESIGN TECHNOLOGY, JOB DESCRIPTIONS AND SUGGESTED TECHNIQUES FOR DETERMINING COURSES OF STUDY IN VOCATIONAL EDUCATION PROGRAMS.

    ERIC Educational Resources Information Center

    PETERSON, CLARENCE E.

    THIS IS THE FIRST OF A SERIES DESIGNED TO PROVIDE AID TO STATES IN ORGANIZING AND OPERATING PROGRAMS UNDER TITLE VIII OF THE NATIONAL DEFENSE EDUCATION ACT, PUBLIC LAW 85-864. IT FURNISHES--(1) GENERAL INFORMATION ABOUT A TECHNOLOGY OR BROAD FIELD OF WORK, (2) COMPOSITE JOB DESCRIPTIONS OF REPRESENTATIVE OCCUPATIONS IN THAT FIELD OF WORK, (3) A…

  14. A Descriptive Study of the Use of PROANA 5: A Computerized Technique for the Analysis of Small Group Interaction.

    ERIC Educational Resources Information Center

    Murrow, Wayne

    The purpose of this study was to generate descriptive statistical estimates regarding the expected proportion of occurrence of each of the PROANA 5 (Process Analysis) variables (line usage, clique group, detrimental clique group, leadership, and dominance) in small group communication. A second purpose was to determine the expected pattern of…

  15. Acquisition of teleological descriptions

    NASA Astrophysics Data System (ADS)

    Franke, David W.

    1992-03-01

    Teleology descriptions capture the purpose of an entity, mechanism, or activity with which they are associated. These descriptions can be used in explanation, diagnosis, and design reuse. We describe a technique for acquiring teleological descriptions expressed in the teleology language TeD. Acquisition occurs during design by observing design modifications and design verification. We demonstrate the acquisition technique in an electronic circuit design.

  16. Formal Analysis of Message Passing

    NASA Astrophysics Data System (ADS)

    Siegel, Stephen F.; Gopalakrishnan, Ganesh

    The message passing paradigm underlies many important families of programs - for instance programs in the area of high performance computing that support science and engineering research. Unfortunately, very few formal methods researchers are involved in developing formal analysis tools and techniques for message passing programs. This paper summarizes research being done in our groups in support of this area, specifically with respect to the Message Passing Interface. We emphasize the need for specialized varieties of many familiar notions such as deadlock detection, race analysis, symmetry analysis, partial order reduction, static analysis and symbolic reasoning support. Since these issues are harbingers of those being faced in multicore programming, the time is ripe to build a critical mass of researchers working in this area.

  17. Percutaneous ultrasound-guided aspiration of an anterior cruciate ligament ganglion cyst: description of technique and case presentation.

    PubMed

    Krill, Michael; Peck, Evan

    2014-12-01

    An anterior cruciate ligament ganglion cyst is an infrequent but potentially clinically significant cause of knee pain. Although the cyst may be removed surgically, percutaneous ultrasound-guided anterior cruciate ligament ganglion cyst aspiration and injection is feasible. To our knowledge, we present the first reported case description of the utilization of ultrasound guidance to perform this procedure with a successful clinical outcome. PMID:25088315

  18. The "Sublabral Window" in Arthroscopic Posterior Shoulder Instability Surgery: Description of a Technique for Safe Posterior Glenoid Preparation.

    PubMed

    Patel, Kushal V; Bravman, Jonathan T; McCarty, Eric

    2016-06-01

    Arthroscopic posterior labral repairs for posterior shoulder instability can be challenging. Preparation of the capsulolabral tissue and glenoid bony surface is critical. Iatrogenic injury to the articular cartilage and unwarranted truncation of the capsulolabral tissue are concerns during preparation. As a result, several techniques have been described to potentially avoid these complications. We describe an additional technique for improving access and preparing the capsulolabral tissue and glenoid surface through a "sublabral window." This technique approaches the posterior labrum and glenoid through an already established posterior portal and mitigates iatrogenic injury to the labrum and articular cartilage. The technique is rather simple and easily adaptable. PMID:27656358

  19. CSR-induced emittance growth in achromats: Linear formalism revisited

    NASA Astrophysics Data System (ADS)

    Venturini, M.

    2015-09-01

    We review the R-matrix formalism used to describe Coherent Synchrotron Radiation (CSR)-induced projected emittance growth in electron beam transport lines and establish the connection with a description in terms of the dispersion-invariant function.

  20. Formal-Operational Thinking and the Role of Training.

    ERIC Educational Resources Information Center

    Wyatt, Mollie L.

    Studies exploring the transition from early to middle adolescence have found a significant increase in formal-operational thinking, but it is questionable whether the typical adolescent is capable of consistently applying formal operational logic. To examine the relationship between Piagetian-based training techniques and formal-operational…

  1. Integrated formal operations plan

    SciTech Connect

    Cort, G.; Dearholt, W.; Donahue, S.; Frank, J.; Perkins, B.; Tyler, R.; Wrye, J.

    1994-01-05

    The concept of formal operations (that is, a collection of business practices to assure effective, accountable operations) has vexed the Laboratory for many years. To date most attempts at developing such programs have been based upon rigid, compliance-based interpretations of a veritable mountain of Department of Energy (DOE) orders, directives, notices, and standards. These DOE dictates seldom take the broad view but focus on highly specialized programs isolated from the overall context of formal operations. The result is a confusing array of specific, and often contradictory, requirements that produce a patchwork of overlapping niche programs. This unnecessary duplication wastes precious resources, dramatically increases the complexity of our work processes, and communicates a sense of confusion to our customers and regulators. Coupled with the artificial divisions that have historically existed among the Laboratory`s formal operations organizations (quality assurance, configuration management, records management, training, etc.), this approach has produced layers of increasingly vague and complex formal operations plans, each of which interprets its parent and adds additional requirements of its own. Organizational gridlock ensues whenever an activity attempts to implement these bureaucratic monstrosities. The integrated formal operations plan presented is to establish a set of requirements that must be met by an integrated formal operations program, assign responsibilities for implementation and operation of the program, and specify criteria against which the performance of the program will be measured. The accountable line manager specifies the items, processes, and information (the controlled elements) to which the formal operations program specified applies. The formal operations program is implemented using a graded approach based on the level of importance of the various controlled elements and the scope of the activities in which they are involved.

  2. In vitro description of a new technique for stapled side-to-side jejunocecal anastomosis in horses and CT scan anatomical comparison with other techniques

    PubMed Central

    2014-01-01

    Background Stapled jejunocecal anastomoses are commonly performed in equine abdominal surgery. They carry higher complication rates compared to handsewn techniques. In human surgery various causes likely to lead to failure of stapled techniques have been evaluated, including staple line failure. Recently Freeman proposed a technique to perform a stapled jejunocecal anastomosis in horses while avoiding blind pouch formation. The aim of this study is to describe a method for stapled side-to-side jejunocecal anastomosis in horses and to compare it with other techniques with computed tomography to assess stomal area, shape and blind pouch size. Methods Intestinal specimens comprising the cecum, ileum and jejunum from 18 horses were collected and were divided into three groups. In Group S a standard stapled side-to-side jejunocecal anastomosis was performed. In Group F the anastomosis was performed using a modified technique proposed by Freeman. In Group G the anastomosis was performed with a modified technique proposed by the authors. Inflated bowel segments were CT scanned to obtain a MultiPlanar Reconstruction of the stoma and afferent small intestine before calculating the cross-sectional area of each of these regions. The ratio of the measured areas was compared between the three techniques. The volume of the blind-end pouch was measured and its ratio with the intestinal area compared between techniques. The cecum was opened and the length of the stoma measured with a caliper and compared to the intended initial length. Results The stomal/intestinal area ratio was not significantly different between techniques. No statistically significant difference was found in the stomal ideal/real perimeter ratio. There was no statistically significant difference in the intended/real stomal length ratio, and all techniques featured an increase in stomal length ranging from 2 to 12 %. Blind pouch formation was a consistent finding in Group S and was virtually absent in Groups F

  3. Pedagogical Basis of DAS Formalism in Engineering Education

    ERIC Educational Resources Information Center

    Hiltunen, J.; Heikkinen, E.-P.; Jaako, J.; Ahola, J.

    2011-01-01

    The paper presents a new approach for a bachelor-level curriculum structure in engineering. The approach is called DAS formalism according to its three phases: description, analysis and synthesis. Although developed specifically for process and environmental engineering, DAS formalism has a generic nature and it could also be used in other…

  4. Description of a computer program and numerical techniques for developing linear perturbation models from nonlinear systems simulations

    NASA Technical Reports Server (NTRS)

    Dieudonne, J. E.

    1978-01-01

    A numerical technique was developed which generates linear perturbation models from nonlinear aircraft vehicle simulations. The technique is very general and can be applied to simulations of any system that is described by nonlinear differential equations. The computer program used to generate these models is discussed, with emphasis placed on generation of the Jacobian matrices, calculation of the coefficients needed for solving the perturbation model, and generation of the solution of the linear differential equations. An example application of the technique to a nonlinear model of the NASA terminal configured vehicle is included.

  5. Software Formal Inspections Standard

    NASA Technical Reports Server (NTRS)

    1993-01-01

    This Software Formal Inspections Standard (hereinafter referred to as Standard) is applicable to NASA software. This Standard defines the requirements that shall be fulfilled by the software formal inspections process whenever this process is specified for NASA software. The objective of this Standard is to define the requirements for a process that inspects software products to detect and eliminate defects as early as possible in the software life cycle. The process also provides for the collection and analysis of inspection data to improve the inspection process as well as the quality of the software.

  6. Analyst in the Nursery: An Application of Child Analytic Techniques in a Therapeutic Nursery. I. A Schematic Description.

    ERIC Educational Resources Information Center

    Kliman, Gilbert

    The Cornerstone Project is an application of child psychoanalytic techniques in synergy with therapeutic nursery education. The Cornerstone School and the method associated with it provide treatment for children ages three to six years within a nursery classroom group setting. A therapist works six or more hours per week in the classroom, during…

  7. Correlates of Formal Reasoning.

    ERIC Educational Resources Information Center

    Linn, Marcia C.; Pulos, Steven

    This study of Piagetian formal reasoning in seventh grade students reports the relationships between four aspects of the ability to control variables in an experiment and the relationships between those four aspects and other constructs. The four aspects of the ability to control variables identified are: (1) set up a controlled experiment, (2)…

  8. Formal synthesis of (+)-discodermolide.

    PubMed

    Francavilla, Charles; Chen, Weichun; Kinder, Frederick R

    2003-04-17

    [structure: see text] Herein we report the formal total synthesis of (+)-discodermolide in 21 steps (longest linear sequence) from commercially available Roche ester. This synthesis features the assembly of C(9-18) and C(19-24) fragments via a metal-chelated aldol coupling reaction.

  9. Adolescence and Formal Operations

    ERIC Educational Resources Information Center

    Blasi, A.; Hoeffel, E. C.

    1974-01-01

    Analyzes the relationship between the development of formal operations and the development of the adolescent personality, as hypothesized by Inhelder and Piaget. It is suggested that the concepts of possibility and reflectivity have a variety of meanings, and that once these meanings are examined, the logical foundation for the…

  10. A non-commuting stabilizer formalism

    SciTech Connect

    Ni, Xiaotong; Van den Nest, Maarten; Buerschaper, Oliver

    2015-05-15

    We propose a non-commutative extension of the Pauli stabilizer formalism. The aim is to describe a class of many-body quantum states which is richer than the standard Pauli stabilizer states. In our framework, stabilizer operators are tensor products of single-qubit operators drawn from the group 〈αI, X, S〉, where α = e{sup iπ/4} and S = diag(1, i). We provide techniques to efficiently compute various properties related to bipartite entanglement, expectation values of local observables, preparation by means of quantum circuits, parent Hamiltonians, etc. We also highlight significant differences compared to the Pauli stabilizer formalism. In particular, we give examples of states in our formalism which cannot arise in the Pauli stabilizer formalism, such as topological models that support non-Abelian anyons.

  11. Formal analysis of electromagnetic optics

    NASA Astrophysics Data System (ADS)

    Khan-Afshar, Sanaz; Hasan, Osman; Tahar, Sofiène

    2014-09-01

    Optical systems are increasingly being used in safety-critical applications. Due to the complexity and sensitivity of optical systems, their verification raises many challenges for engineers. Traditionally, the analysis of such systems has been carried out by paper-and-pencil based proofs and numerical computations. However, these techniques cannot provide accurate results due to the risk of human error and inherent approximations of numerical algorithms. In order to overcome these limitations, we propose to use theorem proving (i.e., a computer-based technique that allows to express mathematical expressions and reason about their correctness by taking into account all the details of mathematical reasoning) as a complementary approach to improve optical system analysis. This paper provides a higher-order logic (a language used to express mathematical theories) formalization of electromagnetic optics in the HOL Light theorem prover. In order to demonstrate the practical effectiveness of our approach, we present the analysis of resonant cavity enhanced photonic devices.

  12. Innovative techniques for the description of reservoir heterogeneity using tracers. Second technical annual progress report, October 1991--September 1992

    SciTech Connect

    Pope, G.A.; Sepehrnoori, K.

    1992-12-31

    This second annual report on innovative uses of tracers for reservoir characterization contains four sections each describing a novel use of oilfield tracers. The first section describes and illustrates the use of a new single-well tracer test to estimate wettability. This test consists of the injection of brine containing tracers followed by oil containing tracers, a shut-in period to allow some of the tracers to react, and then production of the tracers. The inclusion of the oil injection slug with tracers is unique to this test, and this is what makes the test work. We adapted our chemical simulator, UTCHEM, to enable us to study this tracer method and made an extensive simulation study to evaluate the effects of wettability based upon characteristic curves for relative permeability and capillary pressure for differing wetting states typical of oil reservoirs. The second section of this report describes a new method for analyzing interwell tracer data based upon a type-curve approach. Theoretical frequency response functions were used to build type curves of ``transfer function`` and ``phase spectrum`` that have dimensionless heterogeneity index as a parameter to characterize a stochastic permeability field. We illustrate this method by analyzing field tracer data. The third section of this report describes a new theory for interpreting interwell tracer data in terms of channeling and dispersive behavior for reservoirs. Once again, a stochastic approach to reservoir description is taken. The fourth section of this report describes our simulation of perfluorocarbon gas tracers. This new tracer technology developed at Brookhaven National Laboratory is being tested at the Elk Hills Naval Petroleum Reserve No. 1 in California. We report preliminary simulations made of these tracers in one of the oil reservoirs under evaluation with these tracers in this field. Our compostional simulator (UTCOMP) was used for this simulation study.

  13. A new technique to make transparent teeth without decalcifying: description of the methodology and micro-hardness assessment.

    PubMed

    Malentacca, Augusto; Lajolo, Carlo

    2015-01-01

    Diaphanisation and other in vitro endodontic models (i.e., plastic blocks, micro-CT reconstruction, computerised models) do not recreate real root canal working conditions: a more realistic endodontic model is essential for testing endodontic devices and teaching purposes. The aim of this study was to describe a new technique to construct transparent teeth without decalcifying and evaluate the micro-hardness of so treated teeth. Thirty freshly extracted teeth were randomly divided into three groups as follows: 10 non-treated teeth (4 molars, 3 premolars, 3 incisors; control group - G1), 10 teeth were diaphanised (4 molars, 4 premolars, 2 incisors - G2) and 10 teeth were treated with the new proposed technique (2 molars, 6 premolars, 2 incisors - G3). Vickers hardness tester (MHT-4 and AxioVision microscope, Carl Zeiss, 37030 Gottingen, Germany - load=50 g, dwell time=20s, slope=5, 50× magnification) was used to determine microhardness (Vickers Hardness Number - VHN). Statistical analysis was performed using the Intercooled Stata 8.0 software (Stata Corporation, College Station, TX, USA). Only groups 1 and 3 could be tested for hardness because diaphanised teeth were too tender and elastic. Differences in enamel VHN were observed between G1 (mean 304.29; DS=10.44; range 283-321) and G3 (mean 318.51; DS=14.36; range 295.5-339.2) - (p<0.05); differences in dentine VHN were observed between G1 (mean 74.73; DS=6.62; range 63.9-88.1) and G3 (mean 64.54; DS=5.55; range 51.2-72.3) - (p<0.05). G3 teeth presented a slightly lower VHN compared to G1, probably due to some little structural differences among groups, and were dramatically harder than the diaphanised teeth. The described technique, thus, can be considered ideal for testing endodontic instruments and for teaching purposes.

  14. Apparatus description and data analysis of a radiometric technique for measurements of spectral and total normal emittance

    NASA Technical Reports Server (NTRS)

    Edwards, S. F.; Kantsios, A. G.; Voros, J. P.; Stewart, W. F.

    1975-01-01

    The development of a radiometric technique for determining the spectral and total normal emittance of materials heated to temperatures of 800, 1100, and 1300 K by direct comparison with National Bureau of Standards (NBS) reference specimens is discussed. Emittances are measured over the spectral range of 1 to 15 microns and are statistically compared with NBS reference specimens. Results are included for NBS reference specimens, Rene 41, alundum, zirconia, AISI type 321 stainless steel, nickel 201, and a space-shuttle reusable surface insulation.

  15. HOW CAN BONE TUNNEL ENLARGEMENT IN ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION SURGERY BE MEASURED? DESCRIPTION OF A TECHNIQUE

    PubMed Central

    Aguiar Leonardi, Adriano Barros de; Severino, Nilson Roberto; Junior, Aires Duarte

    2015-01-01

    To assess the presence of tibial bone tunnel enlargement after surgery to reconstruct the anterior cruciate ligament using quadruple flexor tendon grafts, and to propose a new technique for its measurement. Methods: The study involved 25 patients aged 18-43 years over a six-month period. The assessment was based on radiographs taken immediately postoperatively and in the third and sixth months of evolution after operations to reconstruct the anterior cruciate ligament using grafts from the tendons of the semitendinosus and gracilis muscles, fixed in the femur with a transverse metal screw and in the tibia with an interference screw. The radiographs were evaluated in terms of the relative value between the diameter of the tunnel and the bone, both at 2 cm below the medial tibial condyle. Results: There were significant increases in tunnel diameters: 20.56% for radiographs in anteroposterior view and 26.48% in lateral view. Enlargement was present in 48% of anteroposterior and lateral radiographs, but was present in both views in only 16% of the cases. Conclusions: Bone tunnel enlargement is a phenomenon found in the first months after surgery to reconstruct the anterior cruciate ligament. The measurement technique proposed in this study was sufficient to detect it. PMID:27027030

  16. Description and interpretation of the bracts epidermis of Gramineae (Poaceae) with rotated image with maximum average power spectrum (RIMAPS) technique.

    PubMed

    Favret, Eduardo A; Fuentes, Néstor O; Molina, Ana M; Setten, Lorena M

    2008-10-01

    During the last few years, RIMAPS technique has been used to characterize the micro-relief of metallic surfaces and recently also applied to biological surfaces. RIMAPS is an image analysis technique which uses the rotation of an image and calculates its average power spectrum. Here, it is presented as a tool for describing the morphology of the trichodium net found in some grasses, which is developed on the epidermal cells of the lemma. Three different species of grasses (herbarium samples) are analyzed: Podagrostis aequivalvis (Trin.) Scribn. & Merr., Bromidium hygrometricum (Nees) Nees & Meyen and Bromidium ramboi (Parodi) Rúgolo. Simple schemes representing the real microstructure of the lemma are proposed and studied. RIMAPS spectra of both the schemes and the real microstructures are compared. These results allow inferring how similar the proposed geometrical schemes are to the real microstructures. Each geometrical pattern could be used as a reference for classifying other species. Finally, this kind of analysis is used to determine the morphology of the trichodium net of Agrostis breviculmis Hitchc. As the dried sample had shrunk and the microstructure was not clear, two kinds of morphology are proposed for the trichodium net of Agrostis L., one elliptical and the other rectilinear, the former being the most suitable.

  17. Description and interpretation of the bracts epidermis of Gramineae (Poaceae) with rotated image with maximum average power spectrum (RIMAPS) technique.

    PubMed

    Favret, Eduardo A; Fuentes, Néstor O; Molina, Ana M; Setten, Lorena M

    2008-10-01

    During the last few years, RIMAPS technique has been used to characterize the micro-relief of metallic surfaces and recently also applied to biological surfaces. RIMAPS is an image analysis technique which uses the rotation of an image and calculates its average power spectrum. Here, it is presented as a tool for describing the morphology of the trichodium net found in some grasses, which is developed on the epidermal cells of the lemma. Three different species of grasses (herbarium samples) are analyzed: Podagrostis aequivalvis (Trin.) Scribn. & Merr., Bromidium hygrometricum (Nees) Nees & Meyen and Bromidium ramboi (Parodi) Rúgolo. Simple schemes representing the real microstructure of the lemma are proposed and studied. RIMAPS spectra of both the schemes and the real microstructures are compared. These results allow inferring how similar the proposed geometrical schemes are to the real microstructures. Each geometrical pattern could be used as a reference for classifying other species. Finally, this kind of analysis is used to determine the morphology of the trichodium net of Agrostis breviculmis Hitchc. As the dried sample had shrunk and the microstructure was not clear, two kinds of morphology are proposed for the trichodium net of Agrostis L., one elliptical and the other rectilinear, the former being the most suitable. PMID:18042391

  18. Novel techniques for biodiversity studies of gordiids and description of a new species of Chordodes (Gordiida, Nematomorpha) from Kenya, Africa.

    PubMed

    Bolek, Matthew G; Szmygiel, Cleo; Kubat, Austin; Schmidt-Rhaesa, Andreas; Hanelt, Ben

    2013-01-01

    We review recent advances in the use of non-adult gordiid cyst stages to locate gordiids over large geographical regions and new culturing techniques which can help overcome current difficulties in nematomorph biodiversity studies. Using these techniques, we collected a new species of gordiid as cysts in aquatic snails (Biomphalaria pfeifferi) from the Lake Victoria Basin, western Kenya, Africa and cultured them in the laboratory. We describe the adult free-living male and female worms using morphological (light and scanning electron microscopy) and molecular data as well as the life cycle, mating and oviposition behavior, egg strings, eggs, larvae, and cysts of this new species. Chordodes kenyaensis n. sp. belongs to a large group of African Chordodes in which simple areoles are smooth or superficially structured less so than "blackberry" areoles but contain filamentous projections. Present among the simple areoles are clusters of bulging areoles, crowned and circurmcluster areoles along with thorn and tubercle areoles. In the laboratory, worms developed and emerged within 53-78 days from three, species of laboratory-reared crickets exposed to cysts of this species. Adult male and female C. kenyaensis n. sp. initiated typical Gordian knots within hours to days of being placed together and males deposited masses of sperm on the cloacal region of females. Females began oviposition within a week of copulating and attached egg strings in a continuous zigzag pattern on small branches or air-hoses but never free in the water column. Larvae hatched within two to three weeks, and cysts developed in laboratory-reared and exposed snails within 14-24 days. Morphological characteristics of egg strings, eggs, larvae and cysts of C. kenyaensis were most similar to other gordiids in the genus Chordodes but differed morphologically from other gordiid genera for which similar information is available.

  19. Semisymmetric systems: Hermitian formalism

    NASA Astrophysics Data System (ADS)

    Buchdahl, H. A.

    1995-04-01

    The power series representing the characteristic function of a regular semisymmetric system involves four linearly independent rotational invariants XA (A=1,.. .,4) that jointly satisfy a quadratic identity. When the X A are appropriately chosen, this takes the form -(X1)2-(X2 )2-(X3)2+( X4)2=0 . The XA are thus the components of a null vector in a four-dimensional Euclidean space whose metric is gAB: =diag(-1,-1 ,-1,1) . Such a vector is equivalent to a simple 2-spinor xi alpha . The intrinsic presence of a spin vector in the formalism used hitherto suggests that it might be of advantage to replace the latter with an explicit 2-spinor formalism. A way of doing this is examined.

  20. Quantification of rainfall prediction uncertainties using a cross-validation based technique. Methodology description and experimental validation.

    NASA Astrophysics Data System (ADS)

    Fraga, Ignacio; Cea, Luis; Puertas, Jerónimo; Salsón, Santiago; Petazzi, Alberto

    2016-04-01

    In this paper we present a new methodology to compute rainfall fields including the quantification of predictions uncertainties using raingauge network data. The proposed methodology comprises two steps. Firstly, the ordinary krigging technique is used to determine the estimated rainfall depth in every point of the study area. Then multiple equi-probable errors fields, which comprise both interpolation and measuring uncertainties, are added to the krigged field resulting in multiple rainfall predictions. To compute these error fields first the standard deviation of the krigging estimation is determined following the cross-validation based procedure described in Delrieu et al. (2014). Then, the standard deviation field is sampled using non-conditioned Gaussian random fields. The proposed methodology was applied to study 7 rain events in a 60x60 km area of the west coast of Galicia, in the Northwest of Spain. Due to its location at the junction between tropical and polar regions, the study area suffers from frequent intense rainfalls characterized by a great variability in terms of both space and time. Rainfall data from the tipping bucket raingauge network operated by MeteoGalicia were used to estimate the rainfall fields using the proposed methodology. The obtained predictions were then validated using rainfall data from 3 additional rain gauges installed within the CAPRI project (Probabilistic flood prediction with high resolution hydrologic models from radar rainfall estimates, funded by the Spanish Ministry of Economy and Competitiveness. Reference CGL2013-46245-R.). Results show that both the mean hyetographs and the peak intensities are correctly predicted. The computed hyetographs present a good fit to the experimental data and most of the measured values fall within the 95% confidence intervals. Also, most of the experimental values outside the confidence bounds correspond to time periods of low rainfall depths, where the inaccuracy of the measuring devices

  1. Posterior lumbar dynamic stabilization instead of arthrodesis for symptomatic adjacent-segment degenerative stenosis: description of a novel technique.

    PubMed

    Mashaly, Hazem; Paschel, Erin E; Khattar, Nicolas K; Goldschmidt, Ezequiel; Gerszten, Peter C

    2016-01-01

    OBJECTIVE The development of symptomatic adjacent-segment disease (ASD) is a well-recognized consequence of lumbar fusion surgery. Extension of a fusion to a diseased segment may only lead to subsequent adjacent-segment degeneration. The authors report the use of a novel technique that uses dynamic stabilization instead of arthrodesis for the surgical treatment of symptomatic ASD following a prior lumbar instrumented fusion. METHODS A cohort of 28 consecutive patients was evaluated who developed symptomatic stenosis immediately adjacent to a previous lumbar instrumented fusion. All patients had symptoms of neurogenic claudication refractory to nonsurgical treatment and were surgically treated with decompression and dynamic stabilization instead of extending the fusion construct using a posterior lumbar dynamic stabilization system. Preoperative symptoms, visual analog scale (VAS) pain scores, and perioperative complications were recorded. Clinical outcome was gauged by comparing VAS scores prior to surgery and at the time of last follow-up. RESULTS The mean follow-up duration was 52 months (range 17-94 months). The mean interval from the time of primary fusion surgery to the dynamic stabilization surgery was 40 months (range 10-96 months). The mean patient age was 51 years (range 29-76 years). There were 19 (68%) men and 9 (32%) women. Twenty-three patients (82%) presented with low-back pain at time of surgery, whereas 24 patients (86%) presented with lower-extremity symptoms only. Twenty-four patients (86%) underwent operations that were performed using single-level dynamic stabilization, 3 patients (11%) were treated at 2 levels, and 1 patient underwent 3-level decompression and dynamic stabilization. The most commonly affected and treated level (46%) was L3-4. The mean preoperative VAS pain score was 8, whereas the mean postoperative score was 3. No patient required surgery for symptomatic degeneration rostral to the level of dynamic stabilization during the

  2. Posterior lumbar dynamic stabilization instead of arthrodesis for symptomatic adjacent-segment degenerative stenosis: description of a novel technique.

    PubMed

    Mashaly, Hazem; Paschel, Erin E; Khattar, Nicolas K; Goldschmidt, Ezequiel; Gerszten, Peter C

    2016-01-01

    OBJECTIVE The development of symptomatic adjacent-segment disease (ASD) is a well-recognized consequence of lumbar fusion surgery. Extension of a fusion to a diseased segment may only lead to subsequent adjacent-segment degeneration. The authors report the use of a novel technique that uses dynamic stabilization instead of arthrodesis for the surgical treatment of symptomatic ASD following a prior lumbar instrumented fusion. METHODS A cohort of 28 consecutive patients was evaluated who developed symptomatic stenosis immediately adjacent to a previous lumbar instrumented fusion. All patients had symptoms of neurogenic claudication refractory to nonsurgical treatment and were surgically treated with decompression and dynamic stabilization instead of extending the fusion construct using a posterior lumbar dynamic stabilization system. Preoperative symptoms, visual analog scale (VAS) pain scores, and perioperative complications were recorded. Clinical outcome was gauged by comparing VAS scores prior to surgery and at the time of last follow-up. RESULTS The mean follow-up duration was 52 months (range 17-94 months). The mean interval from the time of primary fusion surgery to the dynamic stabilization surgery was 40 months (range 10-96 months). The mean patient age was 51 years (range 29-76 years). There were 19 (68%) men and 9 (32%) women. Twenty-three patients (82%) presented with low-back pain at time of surgery, whereas 24 patients (86%) presented with lower-extremity symptoms only. Twenty-four patients (86%) underwent operations that were performed using single-level dynamic stabilization, 3 patients (11%) were treated at 2 levels, and 1 patient underwent 3-level decompression and dynamic stabilization. The most commonly affected and treated level (46%) was L3-4. The mean preoperative VAS pain score was 8, whereas the mean postoperative score was 3. No patient required surgery for symptomatic degeneration rostral to the level of dynamic stabilization during the

  3. A new cable-tie based sternal closure system: description of the device, technique of implantation and first clinical evaluation

    PubMed Central

    2012-01-01

    Background Wire closure still remains the preferred technique despite reasonable disadvantages. Associated complications, such as infection and sternal instability, cause time- and cost-consuming therapies. We present a new tool for sternal closure with its first clinical experience and results. Methods The sternal ZipFixTM System is based on the cable-tie principle. It primarily consists of biocompatible Poly-Ether-Ether-Ketone implants and is predominantly used peristernally through the intercostal space. The system provides a large implant-to-bone contact for better force distribution and for avoiding bone cut through. Results 50 patients were closed with the ZipFixTM system. No sternal instability was observed at 30 days. Two patients developed a mediastinitis that necessitated the removal of the device; however, the ZipFixTM were intact and the sternum remained stable. Conclusions In our initial evaluation, the short-term results have shown that the sternal ZipFixTM can be used safely and effectively. It is fast, easy to use and serves as a potential alternative for traditional wire closure. PMID:22731778

  4. Arthroscopic-Assisted Treatment of a Reversed Hill-Sachs Lesion: Description of a New Technique Using Cerament

    PubMed Central

    Bark, S.; Renken, F.; Schulz, A. P.; Paech, A.; Gille, J.

    2015-01-01

    Purpose. Impaction fractures of the anterior aspect of the humeral head, the reversed Hill-Sachs lesion, are common in posterior shoulder dislocation. We present a new technique to address these lesions arthroscopic-assisted with the use of a bone substitute. Methods. We report the case of a 45-year-old male with a reversed Hill-Sachs lesion after posterior shoulder dislocation. Initially a glenohumeral arthroscopy is performed to address concomitant intra-articular injuries. Guided by the k-wire a cannulated sizer was inserted for reduction of the fracture under arthroscopic visualization. For reduction of the impacted part of the humeral head the subcortical defect was filled with an injectable bone substitute (Cerament) to prevent secondary dislocation. Results. X-ray at follow-up 6 months after the index procedure documents the bony remodeling of the bone substitute. At that time the patient was pain-free (VAS 0) and satisfied with the outcome (Constant score: 78, Rand-36 score: 84, Rowe score: 81) with a good ROM. Conclusions. In conclusion, arthroscopic-assisted reconstruction of reversed Hill-Sachs lesions with an injectable bone substitute is feasible and may provide patients with all the benefits of an anatomic reconstruction with decreased risks related to open surgery. PMID:25688315

  5. Formal verification of an avionics microprocessor

    NASA Technical Reports Server (NTRS)

    Srivas, Mandayam, K.; Miller, Steven P.

    1995-01-01

    Formal specification combined with mechanical verification is a promising approach for achieving the extremely high levels of assurance required of safety-critical digital systems. However, many questions remain regarding their use in practice: Can these techniques scale up to industrial systems, where are they likely to be useful, and how should industry go about incorporating them into practice? This report discusses a project undertaken to answer some of these questions, the formal verification of the AAMPS microprocessor. This project consisted of formally specifying in the PVS language a rockwell proprietary microprocessor at both the instruction-set and register-transfer levels and using the PVS theorem prover to show that the microcode correctly implemented the instruction-level specification for a representative subset of instructions. Notable aspects of this project include the use of a formal specification language by practicing hardware and software engineers, the integration of traditional inspections with formal specifications, and the use of a mechanical theorem prover to verify a portion of a commercial, pipelined microprocessor that was not explicitly designed for formal verification.

  6. Formality of the Chinese collective leadership.

    PubMed

    Li, Haiying; Graesser, Arthur C

    2016-09-01

    We investigated the linguistic patterns in the discourse of four generations of the collective leadership of the Communist Party of China (CPC) from 1921 to 2012. The texts of Mao Zedong, Deng Xiaoping, Jiang Zemin, and Hu Jintao were analyzed using computational linguistic techniques (a Chinese formality score) to explore the persuasive linguistic features of the leaders in the contexts of power phase, the nation's education level, power duration, and age. The study was guided by the elaboration likelihood model of persuasion, which includes a central route (represented by formal discourse) versus a peripheral route (represented by informal discourse) to persuasion. The results revealed that these leaders adopted the formal, central route more when they were in power than before they came into power. The nation's education level was a significant factor in the leaders' adoption of the persuasion strategy. The leaders' formality also decreased with their increasing age and in-power times. However, the predictability of these factors for formality had subtle differences among the different types of leaders. These results enhance our understanding of the Chinese collective leadership and the role of formality in politically persuasive messages. PMID:27406253

  7. Formality of the Chinese collective leadership.

    PubMed

    Li, Haiying; Graesser, Arthur C

    2016-09-01

    We investigated the linguistic patterns in the discourse of four generations of the collective leadership of the Communist Party of China (CPC) from 1921 to 2012. The texts of Mao Zedong, Deng Xiaoping, Jiang Zemin, and Hu Jintao were analyzed using computational linguistic techniques (a Chinese formality score) to explore the persuasive linguistic features of the leaders in the contexts of power phase, the nation's education level, power duration, and age. The study was guided by the elaboration likelihood model of persuasion, which includes a central route (represented by formal discourse) versus a peripheral route (represented by informal discourse) to persuasion. The results revealed that these leaders adopted the formal, central route more when they were in power than before they came into power. The nation's education level was a significant factor in the leaders' adoption of the persuasion strategy. The leaders' formality also decreased with their increasing age and in-power times. However, the predictability of these factors for formality had subtle differences among the different types of leaders. These results enhance our understanding of the Chinese collective leadership and the role of formality in politically persuasive messages.

  8. Formal concept analysis and linguistic hedges

    NASA Astrophysics Data System (ADS)

    Belohlavek, Radim; Vychodil, Vilem

    2012-07-01

    This paper presents an application of linguistic hedges to formal concept analysis of data with fuzzy attributes. Formal concept analysis aims at extraction of particular (bi-)clusters, called formal concepts, from data. The clusters link collections of objects (extents) and attributes (intents), and have a clear interpretation due to a simple verbal description of the concept-forming operators. We insert linguistic hedges such as 'very' or 'extremely' in the description of the operators. In this way, linguistic hedges become parameters for formal concept analysis that control the number of clusters extracted from data. Namely, as we show theoretically as well as experimentally, stronger hedges result in a smaller number of clusters. The new concept-forming operators form Galois-like connections. We study their properties and axiomatize them. Then, we show that a concept lattice with hedges, i.e. the set of all formal concepts of the new operators is indeed a complete lattice which is isomorphic to a particular ordinary concept lattice. We describe the isomorphism and its inverse. These mappings serve as translation procedures. As a consequence, we obtain a theorem characterizing the structure of concept lattices with hedges which generalizes the well-known main theorem of ordinary concept lattices. The isomorphism and its inverse enable us to compute a concept lattice with hedges using algorithms for ordinary concept lattices. We demonstrate by experiments that when selecting various hedges from the strongest to weaker hedges, the reduction in size of the corresponding concept lattices is smooth. From a broader perspective, we argue that linguistic hedges represent mathematically and computationally a feasible way to parameterize methods for knowledge extraction from data that enable one to emphasize or to suppress extracted patterns while keeping their interpretation.

  9. Identifying Concrete and Formal Operational Children.

    ERIC Educational Resources Information Center

    Docherty, Edward M.

    This paper presents a study designed to determine if groups of concrete and formal operational children can be identified through the technique of cluster analysis, using a battery of Piagetian tasks. A Total of 64 subjects, 8 boys and 8 girls from each of the second, fourth, sixth, and eighth grade levels, were selected from a public elementary…

  10. Formal caregivers of older adults: reflection about their practice

    PubMed Central

    Batista, Marina Picazzio Perez; Barros, Juliana de Oliveira; de Almeida, Maria Helena Morgani; Mângia, Elisabete Ferreira; Lancman, Selma

    2014-01-01

    OBJECTIVE To understand the job function of caregivers of older adults and contribute to the debate on the consolidation of this professional practice. METHODOLOGICAL PROCEDURES This is a descriptive, qualitative, and exploratory study. Four focal group sessions were performed in 2011 with 11 elderly companions, formal caregivers of older adults in the Programa Acompanhante de Idosos (Program for Caregivers of Older Adults), Sao Paulo, SP, Southeastern Brazil. These sessions, guided by a semi-structured script, were audio-recorded and fully transcribed. Data were analyzed using the Content Analysis technique, Thematic Modality. RESULTS In view of considering the caregivers of older adults as a new category of workers, it was difficult to define their duties. The elderly companions themselves as well as the care receivers, their families, and the professionals that comprised the team were unclear about their duties. The professional practice of these formal caregivers has been built on the basis of constant discussions and negotiations among them and other team members in Programa Acompanhante de Idosos during daily work. This was achieved via a recognition process of their job functions and by setting apart other workers’ exclusive responsibilities. CONCLUSIONS The delimitation of specific job functions for elderly companions is currently one of the greatest challenges faced by these workers to develop and consolidate their professional role as well as improve Programa Acompanhante de Idosos. PMID:25372163

  11. Formalizing the concept of sound.

    SciTech Connect

    Kaper, H. G.; Tipei, S.

    1999-08-03

    The notion of formalized music implies that a musical composition can be described in mathematical terms. In this article we explore some formal aspects of music and propose a framework for an abstract approach.

  12. Matrix Formalism of Synchrobetatron Coupling

    SciTech Connect

    Huang, Xiaobiao; /SLAC

    2006-10-06

    In this paper we present a complete linear synchrobetatron coupling formalism by studying the transfer matrix which describes linear horizontal and longitudinal motions. With the technique established in the linear horizontal-vertical coupling study [D. Sagan and D. Rubin, Phys. Rev. ST Accel. Beams 2, 074001 (1999)], we found a transformation to block diagonalize the transfer matrix and decouple the betatron motion and the synchrotron motion. By separating the usual dispersion term from the horizontal coordinate first, we were able to obtain analytic expressions of the transformation under reasonable approximations. We also obtained the perturbations to the betatron tune and the Courant-Snyder functions. The closed orbit changes due to finite energy gains at rf cavities and radiation energy losses were also studied by the 5 x 5 extended transfer matrix with the fifth column describing kicks in the 4-dimension phase space.

  13. Covariant Bardeen perturbation formalism

    NASA Astrophysics Data System (ADS)

    Vitenti, S. D. P.; Falciano, F. T.; Pinto-Neto, N.

    2014-05-01

    In a previous work we obtained a set of necessary conditions for the linear approximation in cosmology. Here we discuss the relations of this approach with the so-called covariant perturbations. It is often argued in the literature that one of the main advantages of the covariant approach to describe cosmological perturbations is that the Bardeen formalism is coordinate dependent. In this paper we will reformulate the Bardeen approach in a completely covariant manner. For that, we introduce the notion of pure and mixed tensors, which yields an adequate language to treat both perturbative approaches in a common framework. We then stress that in the referred covariant approach, one necessarily introduces an additional hypersurface choice to the problem. Using our mixed and pure tensors approach, we are able to construct a one-to-one map relating the usual gauge dependence of the Bardeen formalism with the hypersurface dependence inherent to the covariant approach. Finally, through the use of this map, we define full nonlinear tensors that at first order correspond to the three known gauge invariant variables Φ, Ψ and Ξ, which are simultaneously foliation and gauge invariant. We then stress that the use of the proposed mixed tensors allows one to construct simultaneously gauge and hypersurface invariant variables at any order.

  14. 41 CFR 101-29.209 - Purchase description.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Purchase description. 101... DESCRIPTIONS 29.2-Definitions § 101-29.209 Purchase description. A purchase description is any informal product description prepared for one-time use only or for small purchases when issuance of a formal...

  15. 41 CFR 101-29.209 - Purchase description.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 41 Public Contracts and Property Management 2 2011-07-01 2007-07-01 true Purchase description. 101... DESCRIPTIONS 29.2-Definitions § 101-29.209 Purchase description. A purchase description is any informal product description prepared for one-time use only or for small purchases when issuance of a formal...

  16. Conservation-dissipation formalism of irreversible thermodynamics

    NASA Astrophysics Data System (ADS)

    Zhu, Yi; Hong, Liu; Yang, Zaibao; Yong, Wen-An

    2015-06-01

    We propose a conservation-dissipation formalism (CDF) for coarse-grained descriptions of irreversible processes. This formalism is based on a stability criterion for non-equilibrium thermodynamics. The criterion ensures that non-equilibrium states tend to equilibrium in long time. As a systematic methodology, CDF provides a feasible procedure in choosing non-equilibrium state variables and determining their evolution equations. The equations derived in CDF have a unified elegant form. They are globally hyperbolic, allow a convenient definition of weak solutions, and are amenable to existing numerics. More importantly, CDF is a genuinely nonlinear formalism and works for systems far away from equilibrium. With this formalism, we formulate novel thermodynamics theories for heat conduction in rigid bodies and non-isothermal compressible Maxwell fluid flows as two typical examples. In these examples, the non-equilibrium variables are exactly the conjugate variables of the heat fluxes or stress tensors. The new theory generalizes Cattaneo's law or Maxwell's law in a regularized and nonlinear fashion.

  17. Formal Specification of the OpenMP Memory Model

    SciTech Connect

    Bronevetsky, G; de Supinski, B R

    2006-05-17

    OpenMP [1] is an important API for shared memory programming, combining shared memory's potential for performance with a simple programming interface. Unfortunately, OpenMP lacks a critical tool for demonstrating whether programs are correct: a formal memory model. Instead, the current official definition of the OpenMP memory model (the OpenMP 2.5 specification [1]) is in terms of informal prose. As a result, it is impossible to verify OpenMP applications formally since the prose does not provide a formal consistency model that precisely describes how reads and writes on different threads interact. This paper focuses on the formal verification of OpenMP programs through a proposed formal memory model that is derived from the existing prose model [1]. Our formalization provides a two-step process to verify whether an observed OpenMP execution is conformant. In addition to this formalization, our contributions include a discussion of ambiguities in the current prose-based memory model description. Although our formal model may not capture the current informal memory model perfectly, in part due to these ambiguities, our model reflects our understanding of the informal model's intent. We conclude with several examples that may indicate areas of the OpenMP memory model that need further refinement however it is specified. Our goal is to motivate the OpenMP community to adopt those refinements eventually, ideally through a formal model, in later OpenMP specifications.

  18. IDEF3 formalization report

    NASA Technical Reports Server (NTRS)

    Menzel, Christopher; Mayer, Richard J.; Edwards, Douglas D.

    1991-01-01

    The Process Description Capture Method (IDEF3) is one of several Integrated Computer-Aided Manufacturing (ICAM) DEFinition methods developed by the Air Force to support systems engineering activities, and in particular, to support information systems development. These methods have evolved as a distillation of 'good practice' experience by information system developers and are designed to raise the performance level of the novice practitioner to one comparable with that of an expert. IDEF3 is meant to serve as a knowledge acquisition and requirements definition tool that structures the user's understanding of how a given process, event, or system works around process descriptions. A special purpose graphical language accompanying the method serves to highlight temporal precedence and causality relationships relative to the process or event being described.

  19. A Formal Basis for Safety Case Patterns

    NASA Technical Reports Server (NTRS)

    Denney, Ewen; Pai, Ganesh

    2013-01-01

    By capturing common structures of successful arguments, safety case patterns provide an approach for reusing strategies for reasoning about safety. In the current state of the practice, patterns exist as descriptive specifications with informal semantics, which not only offer little opportunity for more sophisticated usage such as automated instantiation, composition and manipulation, but also impede standardization efforts and tool interoperability. To address these concerns, this paper gives (i) a formal definition for safety case patterns, clarifying both restrictions on the usage of multiplicity and well-founded recursion in structural abstraction, (ii) formal semantics to patterns, and (iii) a generic data model and algorithm for pattern instantiation. We illustrate our contributions by application to a new pattern, the requirements breakdown pattern, which builds upon our previous work

  20. Formal methods for Hopfield-like networks.

    PubMed

    Ben Amor, Hedi; Corblin, Fabien; Fanchon, Eric; Elena, Adrien; Trilling, Laurent; Demongeot, Jacques; Glade, Nicolas

    2013-03-01

    Building a meaningful model of biological regulatory network is usually done by specifying the components (e.g. the genes) and their interactions, by guessing the values of parameters, by comparing the predicted behaviors to the observed ones, and by modifying in a trial-error process both architecture and parameters in order to reach an optimal fitness. We propose here a different approach to construct and analyze biological models avoiding the trial-error part, where structure and dynamics are represented as formal constraints. We apply the method to Hopfield-like networks, a formalism often used in both neural and regulatory networks modeling. The aim is to characterize automatically the set of all models consistent with all the available knowledge (about structure and behavior). The available knowledge is formalized into formal constraints. The latter are compiled into Boolean formula in conjunctive normal form and then submitted to a Boolean satisfiability solver. This approach allows to formulate a wide range of queries, expressed in a high level language, and possibly integrating formalized intuitions. In order to explore its potential, we use it to find cycles for 3-nodes networks and to determine the flower morphogenesis regulatory network of Arabidopsis thaliana. Applications of this technique are numerous and concern the building of models from data as well as the design of biological networks possessing specified behaviors. PMID:23381497

  1. New Technologies and Learning Environments: A Perspective from Formal and Non-Formal Education in Baja California, Mexico

    ERIC Educational Resources Information Center

    Zamora, Julieta Lopez; Reynaga, Francisco Javier Arriaga

    2010-01-01

    This paper presents results of two research works, the first approaches non-formal education and the second addresses formal education. In both studies in-depth interview techniques were used. There were some points of convergence between them on aspects such as the implementation of learning environments and the integration of ICT. The interview…

  2. Formalized Epistemology, Logic, and Grammar

    NASA Astrophysics Data System (ADS)

    Bitbol, Michel

    The task of a formal epistemology is defined. It appears that a formal epistemology must be a generalization of "logic" in the sense of Wittgenstein's Tractatus. The generalization is required because, whereas logic presupposes a strict relation between activity and language, this relation may be broken in some domains of experimental enquiry (e.g., in microscopic physics). However, a formal epistemology should also retain a major feature of Wittgenstein's "logic": It must not be a discourse about scientific knowledge, but rather a way of making manifest the structures usually implicit in knowledge-gaining activity. This strategy is applied to the formalism of quantum mechanics.

  3. Formal, Non-Formal and Informal Learning in the Sciences

    ERIC Educational Resources Information Center

    Ainsworth, Heather L.; Eaton, Sarah Elaine

    2010-01-01

    This research report investigates the links between formal, non-formal and informal learning and the differences between them. In particular, the report aims to link these notions of learning to the field of sciences and engineering in Canada and the United States, including professional development of adults working in these fields. It offers…

  4. Toward a Formal Evaluation of Refactorings

    NASA Technical Reports Server (NTRS)

    Paul, John; Kuzmina, Nadya; Gamboa, Ruben; Caldwell, James

    2008-01-01

    Refactoring is a software development strategy that characteristically alters the syntactic structure of a program without changing its external behavior [2]. In this talk we present a methodology for extracting formal models from programs in order to evaluate how incremental refactorings affect the verifiability of their structural specifications. We envision that this same technique may be applicable to other types of properties such as those that concern the design and maintenance of safety-critical systems.

  5. Extension of Liouville Formalism to Postinstability Dynamics

    NASA Technical Reports Server (NTRS)

    Zak, Michail

    2003-01-01

    A mathematical formalism has been developed for predicting the postinstability motions of a dynamic system governed by a system of nonlinear equations and subject to initial conditions. Previously, there was no general method for prediction and mathematical modeling of postinstability behaviors (e.g., chaos and turbulence) in such a system. The formalism of nonlinear dynamics does not afford means to discriminate between stable and unstable motions: an additional stability analysis is necessary for such discrimination. However, an additional stability analysis does not suggest any modifications of a mathematical model that would enable the model to describe postinstability motions efficiently. The most important type of instability that necessitates a postinstability description is associated with positive Lyapunov exponents. Such an instability leads to exponential growth of small errors in initial conditions or, equivalently, exponential divergence of neighboring trajectories. The development of the present formalism was undertaken in an effort to remove positive Lyapunov exponents. The means chosen to accomplish this is coupling of the governing dynamical equations with the corresponding Liouville equation that describes the evolution of the flow of error probability. The underlying idea is to suppress the divergences of different trajectories that correspond to different initial conditions, without affecting a target trajectory, which is one that starts with prescribed initial conditions.

  6. Drought description

    USGS Publications Warehouse

    Matalas, N.C.

    1991-01-01

    What constitutes a comprehensive description of drought, a description forming a basis for answering why a drought occurred is outlined. The description entails two aspects that are "naturally" coupled, named physical and economic, and treats the set of hydrologic measures of droughts in terms of their multivariate distribution, rather than in terms of a collection of the marginal distributions. ?? 1991 Springer-Verlag.

  7. Recognising Women's Skill. EAE647 Non-Formal Learning.

    ERIC Educational Resources Information Center

    Cox, Eva; Leonard, Helen

    The material in this monograph is part of the study materials for the one-semester distance education unit, Non-Formal Learning, in the Open Campus Program at Deakin University (Australia). It is designed to raise issues relating to skill definition. "Choosing a Worker or How Good Are Your Job Descriptions?" explores why interpersonal or…

  8. Male caregivers' use of formal support.

    PubMed

    Coe, M; Neufeld, A

    1999-08-01

    The purpose of this study was to explore male caregivers' perceptions of formal support. The men were caregivers of adults with cognitive impairment. The study involved secondary analysis of interview data on perceptions of support that had not been previously analyzed from the perspective of formal support. Techniques of data analysis used in grounded theory were applied to 62 guided interactive interviews conducted with 24 male caregivers during a period of 18 months. The men experienced a process of making concessions for care in the following four sequential stages: resisting, giving in, opening the door, and making the match. Personal barriers deterred the caregivers from seeking help, and once the caregivers engaged formal help the influence of characteristics of the health care system and individual staff members had both enabling and disabling effects. For caregivers whose use of formal support involved admitting their relative to a long-term care facility, the phase of making the match was followed by redesigning their caregiver role. PMID:11512171

  9. Formal Foundations for Hierarchical Safety Cases

    NASA Technical Reports Server (NTRS)

    Denney, Ewen; Pai, Ganesh; Whiteside, Iain

    2015-01-01

    Safety cases are increasingly being required in many safety-critical domains to assure, using structured argumentation and evidence, that a system is acceptably safe. However, comprehensive system-wide safety arguments present appreciable challenges to develop, understand, evaluate, and manage, partly due to the volume of information that they aggregate, such as the results of hazard analysis, requirements analysis, testing, formal verification, and other engineering activities. Previously, we have proposed hierarchical safety cases, hicases, to aid the comprehension of safety case argument structures. In this paper, we build on a formal notion of safety case to formalise the use of hierarchy as a structuring technique, and show that hicases satisfy several desirable properties. Our aim is to provide a formal, theoretical foundation for safety cases. In particular, we believe that tools for high assurance systems should be granted similar assurance to the systems to which they are applied. To this end, we formally specify and prove the correctness of key operations for constructing and managing hicases, which gives the specification for implementing hicases in AdvoCATE, our toolset for safety case automation. We motivate and explain the theory with the help of a simple running example, extracted from a real safety case and developed using AdvoCATE.

  10. Mending the Gap, An Effort to Aid the Transfer of Formal Methods Technology

    NASA Technical Reports Server (NTRS)

    Hayhurst, Kelly

    2009-01-01

    Formal methods can be applied to many of the development and verification activities required for civil avionics software. RTCA/DO-178B, Software Considerations in Airborne Systems and Equipment Certification, gives a brief description of using formal methods as an alternate method of compliance with the objectives of that standard. Despite this, the avionics industry at large has been hesitant to adopt formal methods, with few developers have actually used formal methods for certification credit. Why is this so, given the volume of evidence of the benefits of formal methods? This presentation will explore some of the challenges to using formal methods in a certification context and describe the effort by the Formal Methods Subgroup of RTCA SC-205/EUROCAE WG-71 to develop guidance to make the use of formal methods a recognized approach.

  11. Formal methods demonstration project for space applications

    NASA Technical Reports Server (NTRS)

    Divito, Ben L.

    1995-01-01

    The Space Shuttle program is cooperating in a pilot project to apply formal methods to live requirements analysis activities. As one of the larger ongoing shuttle Change Requests (CR's), the Global Positioning System (GPS) CR involves a significant upgrade to the Shuttle's navigation capability. Shuttles are to be outfitted with GPS receivers and the primary avionics software will be enhanced to accept GPS-provided positions and integrate them into navigation calculations. Prior to implementing the CR, requirements analysts at Loral Space Information Systems, the Shuttle software contractor, must scrutinize the CR to identify and resolve any requirements issues. We describe an ongoing task of the Formal Methods Demonstration Project for Space Applications whose goal is to find an effective way to use formal methods in the GPS CR requirements analysis phase. This phase is currently under way and a small team from NASA Langley, ViGYAN Inc. and Loral is now engaged in this task. Background on the GPS CR is provided and an overview of the hardware/software architecture is presented. We outline the approach being taken to formalize the requirements, only a subset of which is being attempted. The approach features the use of the PVS specification language to model 'principal functions', which are major units of Shuttle software. Conventional state machine techniques form the basis of our approach. Given this background, we present interim results based on a snapshot of work in progress. Samples of requirements specifications rendered in PVS are offered to illustration. We walk through a specification sketch for the principal function known as GPS Receiver State processing. Results to date are summarized and feedback from Loral requirements analysts is highlighted. Preliminary data is shown comparing issues detected by the formal methods team versus those detected using existing requirements analysis methods. We conclude by discussing our plan to complete the remaining

  12. Unambiguous formalism for higher order Lagrangian field theories

    NASA Astrophysics Data System (ADS)

    Campos, Cédric M.; de León, Manuel; Martín de Diego, David; Vankerschaver, Joris

    2009-11-01

    The aim of this paper is to propose an unambiguous intrinsic formalism for higher order field theories which avoids the arbitrariness in the generalization of the conventional description of field theories, and implies the existence of different Cartan forms and Legendre transformations. We propose a differential-geometric setting for the dynamics of a higher order field theory, based on the Skinner and Rusk formalism for mechanics. This approach incorporates aspects of both the Lagrangian and the Hamiltonian description, since the field equations are formulated using the Lagrangian on a higher order jet bundle and the canonical multisymplectic form on its affine dual. As both of these objects are uniquely defined, the Skinner-Rusk approach has the advantage that it does not suffer from the arbitrariness in conventional descriptions. The result is that we obtain a unique and global intrinsic version of the Euler-Lagrange equations for higher order field theories. Several examples illustrate our construction.

  13. Analyzing phonetic confusions using formal concept analysis.

    PubMed

    Peláez-Moreno, C; García-Moral, A I; Valverde-Albacete, F J

    2010-09-01

    Confusion matrices have been used as a tool for the analysis of speech perception or human speech recognition (HSR) for decades. However, they are rarely employed in automatic speech recognition (ASR) mainly due to the lack of a systematic procedure for their exploration. The generalization of formal concept analysis employed in this paper provides a conceptual interpretation of confusion matrices that enables the analysis of the structure of confusions for both human and machine performances. Generalized formal concept analysis transforms confusion matrices into ordered lattices of confusion events, supporting classic results in HSR that identify a hierarchy of virtual articulatory-acoustic channels. Translating this technique into ASR, a detailed map of the relationships among the speech units employed in the system can be traced to make different sources of confusions apparent: the influence of the lexicon, segmentation errors, dialectal variations or limitations of the feature extraction procedures, among others.

  14. NASA Formal Methods Workshop, 1990

    NASA Technical Reports Server (NTRS)

    Butler, Ricky W. (Compiler)

    1990-01-01

    The workshop brought together researchers involved in the NASA formal methods research effort for detailed technical interchange and provided a mechanism for interaction with representatives from the FAA and the aerospace industry. The workshop also included speakers from industry to debrief the formal methods researchers on the current state of practice in flight critical system design, verification, and certification. The goals were: define and characterize the verification problem for ultra-reliable life critical flight control systems and the current state of practice in industry today; determine the proper role of formal methods in addressing these problems, and assess the state of the art and recent progress toward applying formal methods to this area.

  15. Formalism and functionalism in linguistics.

    PubMed

    Newmeyer, Frederick J

    2010-05-01

    Formalism and functionalism in linguistics are often taken to be diametrically opposed approaches. However, close examination of the relevant phenomena reveals that the two are complementary, rather than being irrevocably in opposition to each other. One can be a formal linguist and a functional linguist at the same time, without there being any contradiction. Copyright © 2010 John Wiley & Sons, Ltd. For further resources related to this article, please visit the WIREs website.

  16. Hardware description languages

    NASA Technical Reports Server (NTRS)

    Tucker, Jerry H.

    1994-01-01

    Hardware description languages are special purpose programming languages. They are primarily used to specify the behavior of digital systems and are rapidly replacing traditional digital system design techniques. This is because they allow the designer to concentrate on how the system should operate rather than on implementation details. Hardware description languages allow a digital system to be described with a wide range of abstraction, and they support top down design techniques. A key feature of any hardware description language environment is its ability to simulate the modeled system. The two most important hardware description languages are Verilog and VHDL. Verilog has been the dominant language for the design of application specific integrated circuits (ASIC's). However, VHDL is rapidly gaining in popularity.

  17. Formal Specification of the OpenMP Memory Model

    SciTech Connect

    Bronevetsky, G; de Supinski, B

    2006-12-19

    OpenMP [2] is an important API for shared memory programming, combining shared memory's potential for performance with a simple programming interface. Unfortunately, OpenMP lacks a critical tool for demonstrating whether programs are correct: a formal memory model. Instead, the current official definition of the OpenMP memory model (the OpenMP 2.5 specification [2]) is in terms of informal prose. As a result, it is impossible to verify OpenMP applications formally since the prose does not provide a formal consistency model that precisely describes how reads and writes on different threads interact. We expand on our previous work that focused on the formal verification of OpenMP programs through a formal memory model [?]. As in that work, our formalization, which is derived from the existing prose model [2], provides a two-step process to verify whether an observed OpenMP execution is conformant. This paper extends the model to cover the entire specification. In addition to this formalization, our contributions include a discussion of ambiguities in the current prose-based memory model description. Although our formal model may not capture the current informal memory model perfectly, in part due to these ambiguities, our model reflects our understanding of the informal model's intent. We conclude with several examples that may indicate areas of the OpenMP memory model that need further refinement, however it is specified. Our goal is to motivate the OpenMP community to adopt those refinements eventually, ideally through a formal model, in later OpenMP specifications.

  18. Formalization of an environmental model using formal concept analysis - FCA

    NASA Astrophysics Data System (ADS)

    Bourdon-García, Rubén D.; Burgos-Salcedo, Javier D.

    2016-08-01

    Nowadays, there is a huge necessity to generate novel strategies for social-ecological systems analyses for resolving global sustainability problems. This paper has as main purpose the application of the formal concept analysis to formalize the theory of Augusto Ángel Maya, who without a doubt, was one of the most important environmental philosophers in South America; Ángel Maya proposed and established that Ecosystem-Culture relations, instead Human-Nature ones, are determinants in our understanding and management of natural resources. Based on this, a concept lattice, formal concepts, subconcept-superconcept relations, partially ordered sets, supremum and infimum of the lattice and implications between attributes (Duquenne-Guigues base), were determined for the ecosystem-culture relations.

  19. Progress with Formalization in Medical Informatics?

    PubMed Central

    van der Maas, Arnoud A.F.; Ten Hoopen, A. Johannes; Ter Hofstede, Arthur H.M.

    2001-01-01

    The prevailing view of medical informatics as a primarily subservient discipline in health care is challenged. Developments in both general informatics and medical informatics are described to identify desirable properties of modeling languages and tools needed to solve key problems in the application field. For progress in medical informatics, it is considered essential to develop far more formal modeling languages, modeling techniques, and tools. A major aim of this development should be to expel ambiguity from concepts essential to medicine, positioning medical informatics “at the heart of health care.” PMID:11230381

  20. Modeling formalisms in Systems Biology

    PubMed Central

    2011-01-01

    Systems Biology has taken advantage of computational tools and high-throughput experimental data to model several biological processes. These include signaling, gene regulatory, and metabolic networks. However, most of these models are specific to each kind of network. Their interconnection demands a whole-cell modeling framework for a complete understanding of cellular systems. We describe the features required by an integrated framework for modeling, analyzing and simulating biological processes, and review several modeling formalisms that have been used in Systems Biology including Boolean networks, Bayesian networks, Petri nets, process algebras, constraint-based models, differential equations, rule-based models, interacting state machines, cellular automata, and agent-based models. We compare the features provided by different formalisms, and discuss recent approaches in the integration of these formalisms, as well as possible directions for the future. PMID:22141422

  1. The Formal Semantics of PVS

    NASA Technical Reports Server (NTRS)

    Owre, Sam; Shankar, Natarajan

    1999-01-01

    A specification language is a medium for expressing what is computed rather than how it is computed. Specification languages share some features with programming languages but are also different in several important ways. For our purpose, a specification language is a logic within which the behavior of computational systems can be formalized. Although a specification can be used to simulate the behavior of such systems, we mainly use specifications to state and prove system properties with mechanical assistance. We present the formal semantics of the specification language of SRI's Prototype Verification System (PVS). This specification language is based on the simply typed lambda calculus. The novelty in PVS is that it contains very expressive language features whose static analysis (e.g., typechecking) requires the assistance of a theorem prover. The formal semantics illuminates several of the design considerations underlying PVS, the interaction between theorem proving and typechecking.

  2. Modeling formalisms in Systems Biology.

    PubMed

    Machado, Daniel; Costa, Rafael S; Rocha, Miguel; Ferreira, Eugénio C; Tidor, Bruce; Rocha, Isabel

    2011-01-01

    Systems Biology has taken advantage of computational tools and high-throughput experimental data to model several biological processes. These include signaling, gene regulatory, and metabolic networks. However, most of these models are specific to each kind of network. Their interconnection demands a whole-cell modeling framework for a complete understanding of cellular systems. We describe the features required by an integrated framework for modeling, analyzing and simulating biological processes, and review several modeling formalisms that have been used in Systems Biology including Boolean networks, Bayesian networks, Petri nets, process algebras, constraint-based models, differential equations, rule-based models, interacting state machines, cellular automata, and agent-based models. We compare the features provided by different formalisms, and discuss recent approaches in the integration of these formalisms, as well as possible directions for the future. PMID:22141422

  3. Formal verification of mathematical software

    NASA Technical Reports Server (NTRS)

    Sutherland, D.

    1984-01-01

    Methods are investigated for formally specifying and verifying the correctness of mathematical software (software which uses floating point numbers and arithmetic). Previous work in the field was reviewed. A new model of floating point arithmetic called the asymptotic paradigm was developed and formalized. Two different conceptual approaches to program verification, the classical Verification Condition approach and the more recently developed Programming Logic approach, were adapted to use the asymptotic paradigm. These approaches were then used to verify several programs; the programs chosen were simplified versions of actual mathematical software.

  4. Pedagogical basis of DAS formalism in engineering education

    NASA Astrophysics Data System (ADS)

    Hiltunen, J.; Heikkinen, E.-P.; Jaako, J.; Ahola, J.

    2011-03-01

    The paper presents a new approach for a bachelor-level curriculum structure in engineering. The approach is called DAS formalism according to its three phases: description, analysis and synthesis. Although developed specifically for process and environmental engineering, DAS formalism has a generic nature and it could also be used in other engineering fields. The motivation for this new curriculum structure originates from the urge to solve the problems that engineering education has faced during the past decades, e.g. student recruitment problems and dissatisfactory learning outcomes. The focus of this paper is on the structure of the curriculum but the content is also discussed when it has an effect on the structure and its implementation. The presented structure, i.e. DAS formalism, builds upon the ideas of some classical pedagogical theories, which have regularly been applied at course level but seldom used to solve curriculum-level issues.

  5. The Traps of Formal Correspondence.

    ERIC Educational Resources Information Center

    Albert, Sandor

    The dangers of translation are discussed when the translator does not try to create textual equivalence, but settles for formal correspondence (i.e., with simple transcoding at a linguistic level) during the process of translating. Difficulties of explaining, commenting, or summarizing rather than translating are also discussed. Pedagogical and…

  6. Integrating Formal Methods and Testing 2002

    NASA Technical Reports Server (NTRS)

    Cukic, Bojan

    2002-01-01

    Traditionally, qualitative program verification methodologies and program testing are studied in separate research communities. None of them alone is powerful and practical enough to provide sufficient confidence in ultra-high reliability assessment when used exclusively. Significant advances can be made by accounting not only tho formal verification and program testing. but also the impact of many other standard V&V techniques, in a unified software reliability assessment framework. The first year of this research resulted in the statistical framework that, given the assumptions on the success of the qualitative V&V and QA procedures, significantly reduces the amount of testing needed to confidently assess reliability at so-called high and ultra-high levels (10-4 or higher). The coming years shall address the methodologies to realistically estimate the impacts of various V&V techniques to system reliability and include the impact of operational risk to reliability assessment. Combine formal correctness verification, process and product metrics, and other standard qualitative software assurance methods with statistical testing with the aim of gaining higher confidence in software reliability assessment for high-assurance applications. B) Quantify the impact of these methods on software reliability. C) Demonstrate that accounting for the effectiveness of these methods reduces the number of tests needed to attain certain confidence level. D) Quantify and justify the reliability estimate for systems developed using various methods.

  7. A formal language for computational systems biology.

    PubMed

    Errampalli, Daniel D; Priami, Corrado; Quaglia, Paola

    2004-01-01

    The post-genomic era has opened new insights into the complex biochemical reaction systems present in the cell and has generated huge amount of information. The biological systems are highly complex and can overwhelm the numerically computable models. Therefore, models employing symbolical techniques might provide a faster insight. This paper presents some preliminary results and recent trends in the above direction. Specifically, it presents an overview of the main features of some formalisms and techniques from the field of specification languages for concurrency and mobility, which have been proposed to model and simulate the dynamics of the interaction of complex biological systems. The ultimate goal of these symbolic approaches is the modeling, analysis, simulation, and hopefully prediction of the behavior of biological systems (vs. biological components).

  8. Management control system description

    SciTech Connect

    Bence, P. J.

    1990-10-01

    This Management Control System (MCS) description describes the processes used to manage the cost and schedule of work performed by Westinghouse Hanford Company (Westinghouse Hanford) for the US Department of Energy, Richland Operations Office (DOE-RL), Richland, Washington. Westinghouse Hanford will maintain and use formal cost and schedule management control systems, as presented in this document, in performing work for the DOE-RL. This MCS description is a controlled document and will be modified or updated as required. This document must be approved by the DOE-RL; thereafter, any significant change will require DOE-RL concurrence. Westinghouse Hanford is the DOE-RL operations and engineering contractor at the Hanford Site. Activities associated with this contract (DE-AC06-87RL10930) include operating existing plant facilities, managing defined projects and programs, and planning future enhancements. This document is designed to comply with Section I-13 of the contract by providing a description of Westinghouse Hanford's cost and schedule control systems used in managing the above activities. 5 refs., 22 figs., 1 tab.

  9. Surgical reconstruction of PIP joint collateral ligament in chronic instability in a high performance athlete: case report and description of technique.

    PubMed

    Mantovani, Gustavo; Pavan, Alexandre; Aita, Marcio A; Argintar, Evan

    2011-06-01

    We present a case report describing the surgical technique for the reconstruction of the proximal interphalangeal (PIP) joint collateral ligament using autograft palmaris longus tendon graft. We accomplished this successfully in a high performance professional athlete presenting with chronic instability of the PIP joint. Our surgical reconstructive technique recreated anatomic ligament position, while correcting multidirectional instability without disruption of the other dynamic anatomic structures of the PIP joint. Our results demonstrated excellent clinical and functional results, and we offer our technique as an alternative to tenodesis procedures for individuals with professions that demand PIP motion.

  10. Formalization of treatment guidelines using Fuzzy Cognitive Maps and semantic web tools.

    PubMed

    Papageorgiou, Elpiniki I; Roo, Jos De; Huszka, Csaba; Colaert, Dirk

    2012-02-01

    Therapy decision making and support in medicine deals with uncertainty and needs to take into account the patient's clinical parameters, the context of illness and the medical knowledge of the physician and guidelines to recommend a treatment therapy. This research study is focused on the formalization of medical knowledge using a cognitive process, called Fuzzy Cognitive Maps (FCMs) and semantic web approach. The FCM technique is capable of dealing with situations including uncertain descriptions using similar procedure such as human reasoning does. Thus, it was selected for the case of modeling and knowledge integration of clinical practice guidelines. The semantic web tools were established to implement the FCM approach. The knowledge base was constructed from the clinical guidelines as the form of if-then fuzzy rules. These fuzzy rules were transferred to FCM modeling technique and, through the semantic web tools, the whole formalization was accomplished. The problem of urinary tract infection (UTI) in adult community was examined for the proposed approach. Forty-seven clinical concepts and eight therapy concepts were identified for the antibiotic treatment therapy problem of UTIs. A preliminary pilot-evaluation study with 55 patient cases showed interesting findings; 91% of the antibiotic treatments proposed by the implemented approach were in fully agreement with the guidelines and physicians' opinions. The results have shown that the suggested approach formalizes medical knowledge efficiently and gives a front-end decision on antibiotics' suggestion for cystitis. Concluding, modeling medical knowledge/therapeutic guidelines using cognitive methods and web semantic tools is both reliable and useful.

  11. Formal methods in the development of safety critical software systems

    SciTech Connect

    Williams, L.G.

    1991-11-15

    As the use of computers in critical control systems such as aircraft controls, medical instruments, defense systems, missile controls, and nuclear power plants has increased, concern for the safety of those systems has also grown. Much of this concern has focused on the software component of those computer-based systems. This is primarily due to historical experience with software systems that often exhibit larger numbers of errors than their hardware counterparts and the fact that the consequences of a software error may endanger human life, property, or the environment. A number of different techniques have been used to address the issue of software safety. Some are standard software engineering techniques aimed at reducing the number of faults in a software protect, such as reviews and walkthroughs. Others, including fault tree analysis, are based on identifying and reducing hazards. This report examines the role of one such technique, formal methods, in the development of software for safety critical systems. The use of formal methods to increase the safety of software systems is based on their role in reducing the possibility of software errors that could lead to hazards. The use of formal methods in the development of software systems is controversial. Proponents claim that the use of formal methods can eliminate errors from the software development process, and produce programs that are probably correct. Opponents claim that they are difficult to learn and that their use increases development costs unacceptably. This report discusses the potential of formal methods for reducing failures in safety critical software systems.

  12. Anaphoric Descriptions

    ERIC Educational Resources Information Center

    Beller, Charley

    2013-01-01

    The study of definite descriptions has been a central part of research in linguistics and philosophy of language since Russell's seminal work "On Denoting" (Russell 1905). In that work Russell quickly dispatches analyses of denoting expressions with forms like "no man," "some man," "a man," and "every…

  13. Combination of Different In Situ Characterization Techniques and Scanning Electron Microscopy Investigations for a Comprehensive Description of the Tensile Deformation Behavior of a CrMnNi TRIP/TWIP Steel

    NASA Astrophysics Data System (ADS)

    Weidner, Anja; Biermann, Horst

    2015-08-01

    The class of low-carbon, high-alloy CrMnNi steels exhibits outstanding mechanical properties with respect to high strength and ductility due to either transformation-induced plasticity (TRIP) or twinning-induced plasticity (TWIP) effect depending on chemical composition and deformation temperature. However, the ongoing deformation mechanisms like the formation of stacking faults, martensitic phase transformation or deformation-induced twinning are overlapping and the kinetics of the microstructure evolution are quite complex. Therefore, in addition to macroscopic deformation tests and microstructural investigations by scanning electron microscopy, a combination of several in situ characterization techniques with either high lateral and/or temporal resolution as well as providing integral volume information were chosen in order to give a thoroughly and comprehensive description of the deformation behavior of CrMnNi TRIP/TWIP steels. In addition, the complementary in situ techniques like in situ nanoindentation, micro-digital image correlation, and acoustic emission measurements provide excellent possibility for description of materials behavior on a multiscale level from the submicrometer scale up to the macroscopic range. The results obtained by the complementary techniques can support the future modeling of the deformation behavior of TRIP/TWIP steels dependent on chemical composition, temperature, grain size and grain orientation.

  14. Formalizing narratives using nested circumscription

    SciTech Connect

    Baral, C.; Gabaldon, A.; Provetti, A.

    1996-12-31

    The representation of narratives of actions and observations is a current issue in Knowledge Representation, where traditional plan-oriented treatments of action seem to fall short. To address narratives, Pinto and Reiter have extended Situation Calculus axioms, Kowalski and Sergot have introduced the Event Calculus in Logic Programming, and Baral et al. have defined the specification language L which allows to express actual and hypothetical situations in a uniform setting. The L entailment relation can formalize several forms of reasoning about actions and change. In this paper we illustrate a translation of L theories into Nested Abnormality Theories, a novel form of circumscription. The proof of soundness and completeness of the translation is the main technical result of the paper, but attention is also devoted to the features of Nested Abnormality Theories to capture commonsense reasoning in general and to clarify which assumptions a logical formalization forces upon a domain. These results also help clarifying the relationship between L and other recent circumscriptive formalization for narratives, such as Miller and Shanahan`s.

  15. A very general electromagnetic gyrokinetic formalism

    NASA Astrophysics Data System (ADS)

    McMillan, B. F.; Sharma, A.

    2016-09-01

    We derive a gyrokinetic formalism which is very generally valid: the ordering allows both large inhomogeneities in plasma flow and magnetic field at long wavelength, such as typical drift-kinetic theories, as well as fluctuations at the gyro-scale. The underlying approach is to order the vorticity to be small, and to assert that the timescales in the local plasma frame are long compared to the gyrofrequency. Unlike most other derivations, we do not treat the long and short wavelength components of the fluctuating fields separately; the single-field description defines the particle motion and their interaction with the electromagnetic field at small-scale, the system-scale, and intermediate length scales in a unified fashion. As in earlier literature, the work consists of identifying a coordinate system where the gyroangle-dependent terms are small, and using a near-unity transform to systematically find a set of coordinates where the gyroangle dependence vanishes. We derive a gyrokinetic Lagrangian which is valid where the vorticity | ∇ × ( E × B / B ) | is small compared to the gyrofrequency Ω, and the magnetic field scale length is long compared to the gyroradius; we also require that time variation be slow in an appropriately chosen reference frame. This appears to be a minimum set of constraints on a gyrokinetic theory and is substantially more general than earlier approaches. It is the general-geometry electromagnetic extension of Dimits, Phys. Plasmas 17, 055901 (2010) (which is an electrostatic formalism with a homogeneous background magnetic field). This approach also does not require a separate treatment of fluctuating and background components of the magnetic field, unlike much of the previous literature. As a consequence, the "cross terms" due to a combination of long- and short-wavelength variation, which were ignored in the earlier work (but derived in a more restrictive ordering in Parra and Calvo, Plasma Phys. Controlled Fusion 53, 045001 (2011

  16. CRAC2 model description

    SciTech Connect

    Ritchie, L.T.; Alpert, D.J.; Burke, R.P.; Johnson, J.D.; Ostmeyer, R.M.; Aldrich, D.C.; Blond, R.M.

    1984-03-01

    The CRAC2 computer code is a revised version of CRAC (Calculation of Reactor Accident Consequences) which was developed for the Reactor Safety Study. This document provides an overview of the CRAC2 code and a description of each of the models used. Significant improvements incorporated into CRAC2 include an improved weather sequence sampling technique, a new evacuation model, and new output capabilities. In addition, refinements have been made to the atmospheric transport and deposition model. Details of the modeling differences between CRAC2 and CRAC are emphasized in the model descriptions.

  17. Proceedings of the First NASA Formal Methods Symposium

    NASA Technical Reports Server (NTRS)

    Denney, Ewen (Editor); Giannakopoulou, Dimitra (Editor); Pasareanu, Corina S. (Editor)

    2009-01-01

    Topics covered include: Model Checking - My 27-Year Quest to Overcome the State Explosion Problem; Applying Formal Methods to NASA Projects: Transition from Research to Practice; TLA+: Whence, Wherefore, and Whither; Formal Methods Applications in Air Transportation; Theorem Proving in Intel Hardware Design; Building a Formal Model of a Human-Interactive System: Insights into the Integration of Formal Methods and Human Factors Engineering; Model Checking for Autonomic Systems Specified with ASSL; A Game-Theoretic Approach to Branching Time Abstract-Check-Refine Process; Software Model Checking Without Source Code; Generalized Abstract Symbolic Summaries; A Comparative Study of Randomized Constraint Solvers for Random-Symbolic Testing; Component-Oriented Behavior Extraction for Autonomic System Design; Automated Verification of Design Patterns with LePUS3; A Module Language for Typing by Contracts; From Goal-Oriented Requirements to Event-B Specifications; Introduction of Virtualization Technology to Multi-Process Model Checking; Comparing Techniques for Certified Static Analysis; Towards a Framework for Generating Tests to Satisfy Complex Code Coverage in Java Pathfinder; jFuzz: A Concolic Whitebox Fuzzer for Java; Machine-Checkable Timed CSP; Stochastic Formal Correctness of Numerical Algorithms; Deductive Verification of Cryptographic Software; Coloured Petri Net Refinement Specification and Correctness Proof with Coq; Modeling Guidelines for Code Generation in the Railway Signaling Context; Tactical Synthesis Of Efficient Global Search Algorithms; Towards Co-Engineering Communicating Autonomous Cyber-Physical Systems; and Formal Methods for Automated Diagnosis of Autosub 6000.

  18. A descriptive study of the usage of spinal manipulative therapy techniques within a randomized clinical trial in acute low back pain.

    PubMed

    Hurley, Deirdre A; McDonough, Suzanne M; Baxter, G David; Dempster, Martin; Moore, Ann P

    2005-02-01

    The majority of randomized clinical trials (RCTs) of spinal manipulative therapy have not adequately defined the terms 'mobilization' and 'manipulation', nor distinguished between these terms in reporting the trial interventions. The purpose of this study was to describe the spinal manipulative therapy techniques utilized within a RCT of manipulative therapy (MT; n = 80), interferential therapy (IFT; n = 80), and a combination of both (CT; n = 80) for people with acute low back pain (LBP). Spinal manipulative therapy was defined as any 'mobilization' (low velocity manual force without a thrust) or 'manipulation' (high velocity thrust) techniques of the spine described by Maitland and Cyriax. The 16 physiotherapists, all members of the Society of Orthopaedic Medicine, utilized three spinal manipulative therapy patterns in the RCT: Maitland Mobilization (40.4%, n = 59), Maitland Mobilization/Cyriax Manipulation (40.4%, n = 59) and Cyriax Manipulation (19.1%, n = 28). There was a significant difference between the MT and CT groups in their usage of spinal manipulative therapy techniques (chi2 = 9.178; df = 2; P = 0.01); subjects randomized to the CT group received three times more Cyriax Manipulation (29.2%, n = 21/72) than those randomized to the MT group (9.5%, n = 7/74; df = 1; P = 0.003). The use of mobilization techniques within the trial was comparable with their usage by the general population of physiotherapists in Britain and Ireland for LBP management. However, the usage of manipulation techniques was considerably higher than reported in physiotherapy surveys and may reflect the postgraduate training of trial therapists.

  19. Peer Review of a Formal Verification/Design Proof Methodology

    NASA Technical Reports Server (NTRS)

    1983-01-01

    The role of formal verification techniques in system validation was examined. The value and the state of the art of performance proving for fault-tolerant compuers were assessed. The investigation, development, and evaluation of performance proving tools were reviewed. The technical issues related to proof methodologies are examined. The technical issues discussed are summarized.

  20. Proceedings of the Sixth NASA Langley Formal Methods (LFM) Workshop

    NASA Technical Reports Server (NTRS)

    Rozier, Kristin Yvonne (Editor)

    2008-01-01

    Today's verification techniques are hard-pressed to scale with the ever-increasing complexity of safety critical systems. Within the field of aeronautics alone, we find the need for verification of algorithms for separation assurance, air traffic control, auto-pilot, Unmanned Aerial Vehicles (UAVs), adaptive avionics, automated decision authority, and much more. Recent advances in formal methods have made verifying more of these problems realistic. Thus we need to continually re-assess what we can solve now and identify the next barriers to overcome. Only through an exchange of ideas between theoreticians and practitioners from academia to industry can we extend formal methods for the verification of ever more challenging problem domains. This volume contains the extended abstracts of the talks presented at LFM 2008: The Sixth NASA Langley Formal Methods Workshop held on April 30 - May 2, 2008 in Newport News, Virginia, USA. The topics of interest that were listed in the call for abstracts were: advances in formal verification techniques; formal models of distributed computing; planning and scheduling; automated air traffic management; fault tolerance; hybrid systems/hybrid automata; embedded systems; safety critical applications; safety cases; accident/safety analysis.

  1. Asymmetric Formal Synthesis of Azadirachtin.

    PubMed

    Mori, Naoki; Kitahara, Takeshi; Mori, Kenji; Watanabe, Hidenori

    2015-12-01

    An asymmetric formal synthesis of azadirachtin, a potent insect antifeedant, was accomplished in 30 steps to Ley's synthetic intermediate (longest linear sequence). The synthesis features: 1) rapid access to the optically active right-hand segment starting from the known 5-hydroxymethyl-2-cyclopentenone scaffold; 2) construction of the B and E rings by a key intramolecular tandem radical cyclization; 3) formation of the hemiacetal moiety in the C ring through the α-oxidation of the six-membered lactone followed by methanolysis. PMID:26474211

  2. Knowledge formalization of intelligent building

    NASA Astrophysics Data System (ADS)

    Žáček, Martin

    2016-06-01

    This article aim is understanding the basic knowledge about an intelligent building. The notion of the intelligent building can be called any building equipped with computer and communication technology, which can automatically respond to internal or external stimuli. The result of the intelligent building is an automated and foreseeing of activities that enable to reduce operating costs and increase comfort. The best way to use the intelligent building is for a low-energy building, a passive building, or for building with high savings. The output of this article is the formalization of basic knowledge of the intelligent building by RDF graph.

  3. The formal de Rham complex

    NASA Astrophysics Data System (ADS)

    Zharinov, V. V.

    2013-02-01

    We propose a formal construction generalizing the classic de Rham complex to a wide class of models in mathematical physics and analysis. The presentation is divided into a sequence of definitions and elementary, easily verified statements; proofs are therefore given only in the key case. Linear operations are everywhere performed over a fixed number field {F} = {R},{C}. All linear spaces, algebras, and modules, although not stipulated explicitly, are by definition or by construction endowed with natural locally convex topologies, and their morphisms are continuous.

  4. 47 CFR 8.12 - Formal complaints.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Formal complaints. 8.12 Section 8.12 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRESERVING THE OPEN INTERNET § 8.12 Formal complaints. Any person may file a formal complaint alleging a violation of the rules in this part....

  5. 47 CFR 8.12 - Formal complaints.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Formal complaints. 8.12 Section 8.12 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRESERVING THE OPEN INTERNET § 8.12 Formal complaints. Any person may file a formal complaint alleging a violation of the rules in this part....

  6. 47 CFR 8.12 - Formal Complaints.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Formal Complaints. 8.12 Section 8.12 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRESERVING THE OPEN INTERNET § 8.12 Formal Complaints. Any person may file a formal complaint alleging a violation of the rules in this part....

  7. 47 CFR 8.12 - Formal complaints.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Formal complaints. 8.12 Section 8.12 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRESERVING THE OPEN INTERNET § 8.12 Formal complaints. Any person may file a formal complaint alleging a violation of the rules in this part....

  8. Formal apparatus of soil classification

    NASA Astrophysics Data System (ADS)

    Rozhkov, V. A.

    2011-12-01

    Mathematical tools that may be applied for soil classification purposes are discussed. They include the evaluation of information contained in particular soil attributes, the grouping of soil objects into a given (automatically determined) number of classes, the optimization of the classification decisions, and the development of the models and rules (algorithms) used to classify soil objects. The algorithms of multivariate statistical methods and cluster analysis used for solving these problems are described. The major attention is paid to the development of the systems of informative attributes of soil objects and their classes and to the assessment of the quality of the classification decisions. Particular examples of the solution of the problems of soil classification with the use of formal mathematical methods are given. It is argued that the theoretical and practical problems of classification in science cannot find objective solutions without the application of the modern methods of information analysis. The major problems of the numerical taxonomy of the soil objects described in this paper and the appropriate software tools for their solution should serve as the basis for the creation of not only formal soil classification systems but also the theory of soil classification.

  9. Formal policies for flexible EHR security.

    PubMed

    Blobel, Bernd; Pharow, Peter

    2006-01-01

    State of the Art methodologies for establishing requirements and solutions to securing applications are based on narrative descriptions about the use of available system, sometimes also dedicated to system components. Even nowadays new developments to ruling application security services by the use of predicate logic suffer from being administered manually. Therefore, security and privacy requirements cannot be properly met resulting in restrictions and fears for allowing the use of sensitive data and functions. Because of the sensitivity of personal health information and especially of genetic data with its wider implications beyond the original subject of care, weaknesses in guaranteeing fine-grained security and privacy rules lead to less acceptance or even the avoidance of essential information transfer and use. To overcome the problem, security and privacy have to become properties of the architectural components of the respective health information system. Embedding security into the systems architecture allows for negotiating and enforcing any security and privacy services related to principals, their roles, their relationships, further contextual information as well as other regulations summarized in formally modeled policies. The paper introduces the evolving paradigm of the model-driven architecture, first time also comprehensively deployed for security and privacy services in bio-genetic and health information systems.

  10. Screw-Wire Osteo-Traction: An Adjunctive or Alternative Method of Anatomical Reduction of Multisegment Midfacial Fractures? A Description of Technique and Prospective Study of 40 Patients

    PubMed Central

    O'Regan, Barry; Devine, Maria; Bhopal, Sats

    2013-01-01

    Stable anatomical fracture reduction and segment control before miniplate fixation can be difficult to achieve in comminuted midfacial fractures. Fracture mobilization and reduction methods include Gillies elevation, malar hook, and Dingman elevators. No single method is used universally. Disadvantages include imprecise segment alignment and poor segment stability/control. We have employed screw-wire osteo-traction (SWOT) to address this problem. A literature review revealed two published reports. The aims were to evaluate the SWOT technique effectiveness as a fracture reduction method and to examine rates of revision fixation and plate removal. We recruited 40 consecutive patients requiring open reduction and internal fixation of multisegment midfacial fractures (2009–2012) and employed miniplate osteosynthesis in all patients. SWOT was used as a default reduction method in all patients. The rates of successful fracture reduction achieved by SWOT alone or in combination and of revision fixation and plate removal, were used as outcome indices of the reduction method effectiveness. The SWOT technique achieved satisfactory anatomical reduction in 27/40 patients when used alone. Other reduction methods were also used in 13/40 patients. No patient required revision fixation and three patients required late plate removal. SWOT can be used across the midface fracture pattern in conjunction with other methods or as a sole reduction method before miniplate fixation. PMID:24436763

  11. Screw-wire osteo-traction: an adjunctive or alternative method of anatomical reduction of multisegment midfacial fractures? A description of technique and prospective study of 40 patients.

    PubMed

    O'Regan, Barry; Devine, Maria; Bhopal, Sats

    2013-12-01

    Stable anatomical fracture reduction and segment control before miniplate fixation can be difficult to achieve in comminuted midfacial fractures. Fracture mobilization and reduction methods include Gillies elevation, malar hook, and Dingman elevators. No single method is used universally. Disadvantages include imprecise segment alignment and poor segment stability/control. We have employed screw-wire osteo-traction (SWOT) to address this problem. A literature review revealed two published reports. The aims were to evaluate the SWOT technique effectiveness as a fracture reduction method and to examine rates of revision fixation and plate removal. We recruited 40 consecutive patients requiring open reduction and internal fixation of multisegment midfacial fractures (2009-2012) and employed miniplate osteosynthesis in all patients. SWOT was used as a default reduction method in all patients. The rates of successful fracture reduction achieved by SWOT alone or in combination and of revision fixation and plate removal, were used as outcome indices of the reduction method effectiveness. The SWOT technique achieved satisfactory anatomical reduction in 27/40 patients when used alone. Other reduction methods were also used in 13/40 patients. No patient required revision fixation and three patients required late plate removal. SWOT can be used across the midface fracture pattern in conjunction with other methods or as a sole reduction method before miniplate fixation.

  12. Formal Computer Validation of the Quantum Phase Estimation Algorithm

    NASA Astrophysics Data System (ADS)

    Witzel, Wayne; Rudinger, Kenneth; Sarovar, Mohan; Carr, Robert

    While peer review and scientific consensus provide some assurance to the validity of ideas, people do make mistakes that can slip through the cracks. A plethora of formal methods tools exist and are in use in a variety of settings where high assurance is demanded. Existing tools, however, require a great deal of expertise and lack versatility, demanding a non-trivial translation between a high-level description of a problem and the formal system. Our software, called Prove-It, allows a nearly direct translation between human-recognizable formulations and the underlying formal system. While Prove-It is not designed for particularly efficient automation, a primary goal of other formal methods tools, it is extremely flexible in following a desired line of reasoning (proof structure). This approach is particularly valuable for validating proofs that are already known. We will demonstrate a validation of the Quantum Phase Estimation Algorithm using Prove-It. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000. This work was supported by the Laboratory Directed Research and Development program at Sandia National Laboratories.

  13. Dissociation coefficients of protein adsorption to nanoparticles as quantitative metrics for description of the protein corona: A comparison of experimental techniques and methodological relevance.

    PubMed

    Hühn, Jonas; Fedeli, Chiara; Zhang, Qian; Masood, Atif; Del Pino, Pablo; Khashab, Niveen M; Papini, Emanuele; Parak, Wolfgang J

    2016-06-01

    Protein adsorption to nanoparticles is described as a chemical reaction in which proteins attach to binding sites on the nanoparticle surface. This process is defined by a dissociation coefficient, which tells how many proteins are adsorbed per nanoparticle in dependence of the protein concentration. Different techniques to experimentally determine dissociation coefficients of protein adsorption to nanoparticles are reviewed. Results of more than 130 experiments in which dissociation coefficients have been determined are compared. Data show that different methods, nanoparticle systems, and proteins can lead to significantly different dissociation coefficients. However, we observed a clear tendency of smaller dissociation coefficients upon less negative towards more positive zeta potentials of the nanoparticles. The zeta potential thus is a key parameter influencing protein adsorption to the surface of nanoparticles. Our analysis highlights the importance of the characterization of the parameters governing protein-nanoparticle interaction for quantitative evaluation and objective literature comparison. PMID:26748245

  14. A Formal Approach to Requirements-Based Programming

    NASA Technical Reports Server (NTRS)

    Hinchey, Michael G.; Rash, James L.; Rouff, Christopher A.

    2005-01-01

    No significant general-purpose method is currently available to mechanically transform system requirements into a provably equivalent model. The widespread use of such a method represents a necessary step toward high-dependability system engineering for numerous application domains. Current tools and methods that start with a formal model of a system and mechanically produce a provably equivalent implementation are valuable but not sufficient. The "gap" unfilled by such tools and methods is that the formal models cannot be proven to be equivalent to the requirements. We offer a method for mechanically transforming requirements into a provably equivalent formal model that can be used as the basis for code generation and other transformations. This method is unique in offering full mathematical tractability while using notations and techniques that are well known and well trusted. Finally, we describe further application areas we are investigating for use of the approach.

  15. Weaving a Formal Methods Education with Problem-Based Learning

    NASA Astrophysics Data System (ADS)

    Gibson, J. Paul

    The idea of weaving formal methods through computing (or software engineering) degrees is not a new one. However, there has been little success in developing and implementing such a curriculum. Formal methods continue to be taught as stand-alone modules and students, in general, fail to see how fundamental these methods are to the engineering of software. A major problem is one of motivation — how can the students be expected to enthusiastically embrace a challenging subject when the learning benefits, beyond passing an exam and achieving curriculum credits, are not clear? Problem-based learning has gradually moved from being an innovative pedagogique technique, commonly used to better-motivate students, to being widely adopted in the teaching of many different disciplines, including computer science and software engineering. Our experience shows that a good problem can be re-used throughout a student's academic life. In fact, the best computing problems can be used with children (young and old), undergraduates and postgraduates. In this paper we present a process for weaving formal methods through a University curriculum that is founded on the application of problem-based learning and a library of good software engineering problems, where students learn about formal methods without sitting a traditional formal methods module. The process of constructing good problems and integrating them into the curriculum is shown to be analagous to the process of engineering software. This approach is not intended to replace more traditional formal methods modules: it will better prepare students for such specialised modules and ensure that all students have an understanding and appreciation for formal methods even if they do not go on to specialise in them.

  16. Formal methods technology transfer: Some lessons learned

    NASA Technical Reports Server (NTRS)

    Hamilton, David

    1992-01-01

    IBM has a long history in the application of formal methods to software development and verification. There have been many successes in the development of methods, tools and training to support formal methods. And formal methods have been very successful on several projects. However, the use of formal methods has not been as widespread as hoped. This presentation summarizes several approaches that have been taken to encourage more widespread use of formal methods, and discusses the results so far. The basic problem is one of technology transfer, which is a very difficult problem. It is even more difficult for formal methods. General problems of technology transfer, especially the transfer of formal methods technology, are also discussed. Finally, some prospects for the future are mentioned.

  17. A Comparison of Participation Patterns in Selected Formal, Non-Formal, and Informal Online Learning Environments

    ERIC Educational Resources Information Center

    Schwier, Richard A.; Seaton, J. X.

    2013-01-01

    Does learner participation vary depending on the learning context? Are there characteristic features of participation evident in formal, non-formal, and informal online learning environments? Six online learning environments were chosen as epitomes of formal, non-formal, and informal learning contexts and compared. Transcripts of online…

  18. Why formal learning theory matters for cognitive science.

    PubMed

    Fulop, Sean; Chater, Nick

    2013-01-01

    This article reviews a number of different areas in the foundations of formal learning theory. After outlining the general framework for formal models of learning, the Bayesian approach to learning is summarized. This leads to a discussion of Solomonoff's Universal Prior Distribution for Bayesian learning. Gold's model of identification in the limit is also outlined. We next discuss a number of aspects of learning theory raised in contributed papers, related to both computational and representational complexity. The article concludes with a description of how semi-supervised learning can be applied to the study of cognitive learning models. Throughout this overview, the specific points raised by our contributing authors are connected to the models and methods under review.

  19. Formal analysis of imprecise system requirements with Event-B.

    PubMed

    Le, Hong Anh; Nakajima, Shin; Truong, Ninh Thuan

    2016-01-01

    Formal analysis of functional properties of system requirements needs precise descriptions. However, the stakeholders sometimes describe the system with ambiguous, vague or fuzzy terms, hence formal frameworks for modeling and verifying such requirements are desirable. The Fuzzy If-Then rules have been used for imprecise requirements representation, but verifying their functional properties still needs new methods. In this paper, we propose a refinement-based modeling approach for specification and verification of such requirements. First, we introduce a representation of imprecise requirements in the set theory. Then we make use of Event-B refinement providing a set of translation rules from Fuzzy If-Then rules to Event-B notations. After that, we show how to verify both safety and eventuality properties with RODIN/Event-B. Finally, we illustrate the proposed method on the example of Crane Controller. PMID:27398276

  20. Formal modeling of virtual machines

    NASA Technical Reports Server (NTRS)

    Cremers, A. B.; Hibbard, T. N.

    1978-01-01

    Systematic software design can be based on the development of a 'hierarchy of virtual machines', each representing a 'level of abstraction' of the design process. The reported investigation presents the concept of 'data space' as a formal model for virtual machines. The presented model of a data space combines the notions of data type and mathematical machine to express the close interaction between data and control structures which takes place in a virtual machine. One of the main objectives of the investigation is to show that control-independent data type implementation is only of limited usefulness as an isolated tool of program development, and that the representation of data is generally dictated by the control context of a virtual machine. As a second objective, a better understanding is to be developed of virtual machine state structures than was heretofore provided by the view of the state space as a Cartesian product.

  1. Hamiltonian formalism and the Garrett-Munk spectrum of internal waves in the ocean.

    PubMed

    Lvov, Y V; Tabak, E G

    2001-10-15

    Wave turbulence formalism for long internal waves in a stratified fluid is developed, based on a natural Hamiltonian description. A kinetic equation appropriate for the description of spectral energy transfer is derived, and its anisotropic self-similar stationary solution corresponding to a direct cascade of energy toward the short scales is found. This solution is very close to the high wave-number limit of the Garrett-Munk spectrum of long internal waves in the ocean. In fact, a small modification of the Garrett-Munk formalism includes a spectrum consistent with the one predicted by wave turbulence.

  2. Is V-Y plasty necessary for penile lengthening? Girth enhancement and increased length solely through circumcision: description of a novel technique.

    PubMed

    Mertziotis, Nikos; Kozyrakis, Diomidis; Bogris, Elias

    2013-11-01

    Our objective is to describe a novel ligamentolysis approach using a subcoronal incision technique and to determine its safety and efficacy. During the last 7 years, 82 consecutive patients had penile augmentation surgery. Ligamentolysis, through a lower abdominal incision (V-Y plasty) in the first 35 males, was performed (Group A), followed by circumcision ligamentolysis in the next 47 males (Group B). The operation time, complications, and the preoperative and postoperative values of penile length and girth along with the self-esteem and relations questionnaire score as well as satisfaction score was calculated before and after the surgery, and a comparison was conducted between the groups. The mean age at presentation was 32 years (range: 18-56 years). Seventy-nine patients suffered from penile dysmorphophobia, and three patients had micropenises (length <7.5 cm). The mean surgical times were 150.7 and 125.2 min for Groups A and B, respectively (P=0.005). Postoperatively, four Group A patients and three Group B patients (11% versus 6%, respectively) experienced penile retraction (P=0.453). Hypertrophic scars were observed in 18 men (51%) in the former [corrected] group. In the circumcision group, no major wound complications were recorded. The length and girth improvements between the groups were similar. In terms of satisfaction and SEAR improvement, the resulting difference for both variables favored the circumcision group (P=0.007 and <0.001, respectively). With strict selection criteria, the circumcision ligamentolysis procedure compared to the V-Y plasty demonstrated improved results in terms of safety, operation time, retraction rate and cosmetic appearance without any compromise in the gained penile size. PMID:23792340

  3. Descriptive thermodynamics

    NASA Astrophysics Data System (ADS)

    Ford, David; Huntsman, Steven

    2006-06-01

    Thermodynamics (in concert with its sister discipline, statistical physics) can be regarded as a data reduction scheme based on partitioning a total system into a subsystem and a bath that weakly interact with each other. Whereas conventionally, the systems investigated require this form of data reduction in order to facilitate prediction, a different problem also occurs, in the context of communication networks, markets, etc. Such “empirically accessible” systems typically overwhelm observers with the sort of information that in the case of (say) a gas is effectively unobtainable. What is required for such complex interacting systems is not prediction (this may be impossible when humans besides the observer are responsible for the interactions) but rather, description as a route to understanding. Still, the need for a thermodynamical data reduction scheme remains. In this paper, we show how an empirical temperature can be computed for finite, empirically accessible systems, and further outline how this construction allows the age-old science of thermodynamics to be fruitfully applied to them.

  4. Formal and informal authority of hospital directors.

    PubMed

    Nirel, N; Schmid, H; Stern, Z

    1994-01-01

    Describes and contrasts the perceptions of formal and informal authority of hospital directors of two different kinds of organizations: hospitals that are part of public multi-hospital organizations (PMOs) and independent hospitals. Indicates that all the directors perceive their formal authority to be greater than their formal authority. However, there is a gap in the perception of formal and informal authority by directors of the two types of hospital. Directors of independent hospitals perceive themselves to have more formal and informal authority than do their colleagues at hospitals that are part of PMOs. Both structural and personal explanations for these findings are given. In addition, discusses the implications for policy making of the source of authority, informal, and formal authority in the transition to autonomous semi-independent hospitals in a changing environment.

  5. Anyons in the operational formalism

    NASA Astrophysics Data System (ADS)

    Neori, Klil H.; Goyal, Philip

    2015-01-01

    The operational formalism to quantum mechanics seeks to base the theory on a firm foundation of physically well-motivated axioms [1]. It has succeeded in deriving the Feynman rules [2] for general quantum systems. Additional elaborations have applied the same logic to the question of identical particles, confirming the so-called Symmetrization Postulate [3]: that the only two options available are fermions and bosons [4, 5]. However, this seems to run counter to results in two-dimensional systems, which allow for anyons, particles with statistics which interpolate between Fermi-Dirac and Bose-Einstein (see [6] for a review). In this talk we will show that the results in two dimensions can be made compatible with the operational results. That is, we will show that anyonic behavior is a result of the topology of the space in two dimensions [7], and does not depend on the particles being identical; but that nevertheless, if the particles are identical, the resulting system is still anyonic.

  6. Universal formalism of Fano resonance

    SciTech Connect

    Huang, Liang; Lai, Ying-Cheng; Luo, Hong-Gang; Grebogi, Celso

    2015-01-15

    The phenomenon of Fano resonance is ubiquitous in a large variety of wave scattering systems, where the resonance profile is typically asymmetric. Whether the parameter characterizing the asymmetry should be complex or real is an issue of great experimental interest. Using coherent quantum transport as a paradigm and taking into account of the collective contribution from all available scattering channels, we derive a universal formula for the Fano-resonance profile. We show that our formula bridges naturally the traditional Fano formulas with complex and real asymmetry parameters, indicating that the two types of formulas are fundamentally equivalent (except for an offset). The connection also reveals a clear footprint for the conductance resonance during a dephasing process. Therefore, the emergence of complex asymmetric parameter when fitting with experimental data needs to be properly interpreted. Furthermore, we have provided a theory for the width of the resonance, which relates explicitly the width to the degree of localization of the close-by eigenstates and the corresponding coupling matrices or the self-energies caused by the leads. Our work not only resolves the issue about the nature of the asymmetry parameter, but also provides deeper physical insights into the origin of Fano resonance. Since the only assumption in our treatment is that the transport can be described by the Green’s function formalism, our results are also valid for broad disciplines including scattering problems of electromagnetic waves, acoustics, and seismology.

  7. Anyons in the operational formalism

    SciTech Connect

    Neori, Klil H.; Goyal, Philip

    2015-01-13

    The operational formalism to quantum mechanics seeks to base the theory on a firm foundation of physically well-motivated axioms [1]. It has succeeded in deriving the Feynman rules [2] for general quantum systems. Additional elaborations have applied the same logic to the question of identical particles, confirming the so-called Symmetrization Postulate [3]: that the only two options available are fermions and bosons [4, 5]. However, this seems to run counter to results in two-dimensional systems, which allow for anyons, particles with statistics which interpolate between Fermi-Dirac and Bose-Einstein (see [6] for a review). In this talk we will show that the results in two dimensions can be made compatible with the operational results. That is, we will show that anyonic behavior is a result of the topology of the space in two dimensions [7], and does not depend on the particles being identical; but that nevertheless, if the particles are identical, the resulting system is still anyonic.

  8. Survey of Existing Tools for Formal Verification.

    SciTech Connect

    Punnoose, Ratish J.; Armstrong, Robert C.; Wong, Matthew H.; Jackson, Mayo

    2014-12-01

    Formal methods have come into wide use because of their effectiveness in verifying "safety and security" requirements of digital systems; a set of requirements for which testing is mostly ineffective. Formal methods are routinely used in the design and verification of high-consequence digital systems in industry. This report outlines our work in assessing the capabilities of commercial and open source formal tools and the ways in which they can be leveraged in digital design workflows.

  9. An exploration of student midwives' language to describe non-formal learning in professional practice.

    PubMed

    Finnerty, Gina; Pope, Rosemary

    2005-05-01

    The essence of non-formal learning in midwifery practice has not been previously explored. This paper provides an in-depth analysis of the language of a sample of student midwives' descriptions of their practice learning in a range of clinical settings. The students submitted audio-diaries as part of a national study (Pope, R., Graham. L., Finnerty. G., Magnusson, C. 2003. An investigation of the preparation and assessment for midwifery practice within a range of settings. Project Report. University of Surrey). Participants detailed their learning activities and support obtained whilst working with their named mentors for approximately 10 days or shifts. The rich audio-diary data have been analysed using Discourse Analysis. A typology of non-formal learning (Eraut, M. 2000. Non-formal learning and implicit knowledge in professional work. British Journal of Educational Psychology 70, 113-136) has been used to provide a framework for the analysis. Non-formal learning is defined as any learning which does not take place within a formally organised learning programme (Eraut, M. 2000. Non-formal learning and implicit knowledge in professional work. British Journal of Educational Psychology 70, 113-136). Findings indicate that fear and ambiguity hindered students' learning. Recommendations include the protection of time by mentors within the clinical curriculum to guide and supervise students in both formal and non-formal elements of midwifery practice. This paper will explore the implications of the findings for practice-based education.

  10. Third NASA Langley Formal Methods Workshop

    NASA Technical Reports Server (NTRS)

    Holloway, C. Michael (Compiler)

    1995-01-01

    This publication constitutes the proceedings of NASA Langley Research Center's third workshop on the application of formal methods to the design and verification of life-critical systems. This workshop brought together formal methods researchers, industry engineers, and academicians to discuss the potential of NASA-sponsored formal methods and to investigate new opportunities for applying these methods to industry problems. contained herein are copies of the material presented at the workshop, summaries of many of the presentations, a complete list of attendees, and a detailed summary of the Langley formal methods program. Much of this material is available electronically through the World-Wide Web via the following URL.

  11. The Second NASA Formal Methods Workshop 1992

    NASA Technical Reports Server (NTRS)

    Johnson, Sally C. (Compiler); Holloway, C. Michael (Compiler); Butler, Ricky W. (Compiler)

    1992-01-01

    The primary goal of the workshop was to bring together formal methods researchers and aerospace industry engineers to investigate new opportunities for applying formal methods to aerospace problems. The first part of the workshop was tutorial in nature. The second part of the workshop explored the potential of formal methods to address current aerospace design and verification problems. The third part of the workshop involved on-line demonstrations of state-of-the-art formal verification tools. Also, a detailed survey was filled in by the attendees; the results of the survey are compiled.

  12. Towards a formal semantics for Ada 9X

    NASA Technical Reports Server (NTRS)

    Guaspari, David; Mchugh, John; Wolfgang, Polak; Saaltink, Mark

    1995-01-01

    The Ada 9X language precision team was formed during the revisions of Ada 83, with the goal of analyzing the proposed design, identifying problems, and suggesting improvements, through the use of mathematical models. This report defines a framework for formally describing Ada 9X, based on Kahn's 'natural semantics', and applies the framework to portions of the language. The proposals for exceptions and optimization freedoms are also analyzed, using a different technique.

  13. Planning Non-Formal Education Curricula: The Case of Israel.

    ERIC Educational Resources Information Center

    Keller, Diana; Dror, Ilana

    This paper compares the formal and non-formal education systems currently operating in Israel, describing the special features of curriculum planning in non-formal education. The central argument is that the non-formal education system fulfills functions that constitute a critique of the formal education system. The non-formal system offers the…

  14. A test of the formal and modern theories of matching.

    PubMed

    Dallery, Jesse; Soto, Paul L; McDowell, J J

    2005-09-01

    The present study tested a formal, or purely mathematical, theory of matching, and a modern account derived by McDowell (1986) that incorporates deviations from strict matching-bias and sensitivity. Six humans pressed a lever for monetary reinforcers on five concurrent variable interval (VI) schedules of reinforcement. All schedules were presented during each session. The magnitude on one alternative remained constant, and five magnitudes were presented across sessions on the other alternative. To test the formal account, two absolute response rate equations were fitted to the response and reinforcement rates at each alternative at each magnitude. Although the equations accounted for a high percentage of variance, there was a significant negative correlation between the standardized residuals and the predicted response rates. To test the modern account, an ensemble of four equations was fitted to the data. The equations predicted relative and absolute responding, and the independent variables in each equation were adjusted for bias and sensitivity. The equations accounted for a high percentage of variance, and the standardized residuals were not correlated with the predicted response rates. The values of the parameters were consistent with empirical findings and theoretical predictions, including the prediction that k should remain constant across changes in reinforcer magnitude. The results suggest that the formal theory of matching does not describe the data, and that the modern theory may provide an accurate and coherent description of concurrent and single-alternative responding.

  15. Integrating Formal and Informal Learning at Work

    ERIC Educational Resources Information Center

    Svensson, Lennart; Ellstrom, Per-Erik; Aberg, Carina

    2004-01-01

    A model for workplace learning is presented, which intends to integrate formal and informal learning with the use of e-learning. An important underlying assumption is that the integration of formal and informal learning is necessary in order to create desirable competencies, from both an individual and an organisational perspective. Two case…

  16. The Formalization of Theory and Method.

    ERIC Educational Resources Information Center

    Freese, Lee

    1981-01-01

    Reviews the formalization of theory and method in American sociology since World War II, particularly the growth of systematic-formal theories and quantitative methods for empirical research. Topics discussed include various methods of theorizing, trends in theoretical sociology, and increasing use of quantitative data for data design and…

  17. Male-Female Differences in Formal Thought.

    ERIC Educational Resources Information Center

    Linn, Marcia C.

    Two studies were conducted to clarify the influence of experiences and aptitudes on male-female differences in formal thought. Participants were 788 seventh-, ninth-, and eleventh-graders in three school districts differing in location, socioeconomic composition, and course offerings. Formal thought was measured with tasks involving proportional…

  18. Formal Mentoring Programs and Organizational Attraction

    ERIC Educational Resources Information Center

    Allen, Tammy D.; O'Brien, Kimberly E.

    2006-01-01

    This study was designed to test if formal mentoring programs enhance organizational attraction. Participants were 190 undergraduates looking for a job related to their major. Results indicated that participants were more attracted to an organization when it was depicted as having a formal mentoring program than when it was not so depicted. Drawing…

  19. Do Formal Supports Replace Informal Supports?

    ERIC Educational Resources Information Center

    Barer, Barbara M.; And Others

    Health policy researchers have long been interested in the extent to which the provision of formal supports replaces or undermines the informal support system. This study examined the linkages between the formal and informal support system as they are mediated by a health care setting which readily provides patients with access to social services.…

  20. 37 CFR 251.41 - Formal hearings.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ARBITRATION ROYALTY PANEL RULES AND PROCEDURES COPYRIGHT ARBITRATION ROYALTY PANEL RULES OF PROCEDURE Procedures of Copyright Arbitration Royalty Panels § 251.41 Formal hearings. (a) The formal hearings that... distribution hearings. All parties intending to participate in a hearing of a Copyright Arbitration...

  1. Does (In)Formal Learning Enhance Employability?

    ERIC Educational Resources Information Center

    van der Heijden, Beatrice I.J.M.; Boon, Jo; van der Klink, Marcel R.; Meys, Ely

    2008-01-01

    Not much is known about the actual contribution of informal learning to employability over and above formal learning activities. This paper presents findings of a research project among university staff members and is aimed to determine the contribution of formal and informal learning activities in the light of future career potential. Findings…

  2. 18 CFR 1b.5 - Formal investigations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Formal investigations. 1b.5 Section 1b.5 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES RULES RELATING TO INVESTIGATIONS § 1b.5 Formal investigations....

  3. 18 CFR 1b.5 - Formal investigations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Formal investigations. 1b.5 Section 1b.5 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES RULES RELATING TO INVESTIGATIONS § 1b.5 Formal investigations....

  4. 18 CFR 1b.5 - Formal investigations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Formal investigations. 1b.5 Section 1b.5 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES RULES RELATING TO INVESTIGATIONS § 1b.5 Formal investigations....

  5. 18 CFR 1b.5 - Formal investigations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Formal investigations. 1b.5 Section 1b.5 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES RULES RELATING TO INVESTIGATIONS § 1b.5 Formal investigations....

  6. Multiverse in the Third Quantized Formalism

    NASA Astrophysics Data System (ADS)

    Mir, Faizal

    2014-11-01

    In this paper we will analyze the third quantization of gravity in path integral formalism. We will use the time-dependent version of Wheeler—DeWitt equation to analyze the multiverse in this formalism. We will propose a mechanism for baryogenesis to occur in the multiverse, without violating the baryon number conservation.

  7. 14 CFR 302.404 - Formal complaints.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... business or the ends of justice. (e) Service. A formal complaint, and any amendments thereto, shall be... does so under § 302.406(c). (b) Amendment. A formal complaint may be amended at any time before service of an answer to the complaint. After service of an answer but before institution of an...

  8. 14 CFR 302.404 - Formal complaints.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... business or the ends of justice. (e) Service. A formal complaint, and any amendments thereto, shall be... does so under § 302.406(c). (b) Amendment. A formal complaint may be amended at any time before service of an answer to the complaint. After service of an answer but before institution of an...

  9. 14 CFR 302.404 - Formal complaints.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... business or the ends of justice. (e) Service. A formal complaint, and any amendments thereto, shall be... does so under § 302.406(c). (b) Amendment. A formal complaint may be amended at any time before service of an answer to the complaint. After service of an answer but before institution of an...

  10. 14 CFR 302.404 - Formal complaints.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... business or the ends of justice. (e) Service. A formal complaint, and any amendments thereto, shall be... does so under § 302.406(c). (b) Amendment. A formal complaint may be amended at any time before service of an answer to the complaint. After service of an answer but before institution of an...

  11. 14 CFR 302.404 - Formal complaints.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... business or the ends of justice. (e) Service. A formal complaint, and any amendments thereto, shall be... does so under § 302.406(c). (b) Amendment. A formal complaint may be amended at any time before service of an answer to the complaint. After service of an answer but before institution of an...

  12. 18 CFR 1b.5 - Formal investigations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Formal investigations. 1b.5 Section 1b.5 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES RULES RELATING TO INVESTIGATIONS § 1b.5 Formal investigations....

  13. The Adolescent Personality, Formal Reasoning, and Values.

    ERIC Educational Resources Information Center

    Darmody, John P.

    1991-01-01

    Examined relationship between levels of Piagetian formal reasoning ability and values preferences derived from Rokeach Value Survey. Findings from 448 secondary school students revealed that subjects with high scores on formal reasoning ranked terminal values representing abstract notions with long-term implications higher than those focusing on…

  14. Structuring the formal definition of Ada

    NASA Technical Reports Server (NTRS)

    Hansen, Kurt W.

    1986-01-01

    The structure of the formal definition of Ada are described. At present, a difficult subset of Ada has been defined and the experience gained so far by this work is reported. Currently, the work continues towards the formal definition of the Ada language.

  15. IMGT-Kaleidoscope, the formal IMGT-ONTOLOGY paradigm.

    PubMed

    Duroux, Patrice; Kaas, Quentin; Brochet, Xavier; Lane, Jérôme; Ginestoux, Chantal; Lefranc, Marie-Paule; Giudicelli, Véronique

    2008-04-01

    IMGT, the international ImMunoGeneTics information system (http://imgt.cines.fr), is the reference in immunogenetics and immunoinformatics. IMGT standardizes and manages the complex immunogenetic data which include the immunoglobulins (IG) or antibodies, the T cell receptors (TR), the major histocompatibility complex (MHC) and the related proteins of the immune system (RPI) which belong to the immunoglobulin superfamily (IgSF) and the MHC superfamily (MhcSF). The accuracy and consistency of IMGT data and the coherence between the different IMGT components (databases, tools and Web resources) are based on IMGT-ONTOLOGY, the first ontology for immunogenetics and immunoinformatics. IMGT-ONTOLOGY manages the immunogenetics knowledge through diverse facets relying on seven axioms, "IDENTIFICATION", "DESCRIPTION", "CLASSIFICATION", "NUMEROTATION", "LOCALIZATION", "ORIENTATION" and "OBTENTION", that postulate that objects, processes and relations have to be identified, described, classified, numerotated, localized, orientated, and that the way they are obtained has to be determined. These axioms constitute the Formal IMGT-ONTOLOGY, also designated as IMGT-Kaleidoscope. Through the example of the IG molecular synthesis, the concepts generated from the "IDENTIFICATION", "DESCRIPTION", "CLASSIFICATION" and "NUMEROTATION" axioms are detailed with their main instances and semantic relations. The axioms have been essential for the conceptualization of the molecular immunogenetics knowledge and can be used to generate concepts for multi scale approaches at the molecule, cell, tissue, organ, organism or population level, emphasizing the generalization of the application domain. In that way the Formal IMGT-ONTOLOGY represents a paradigm for the elaboration of ontologies in system biology.

  16. Animating Event B Models by Formal Data Models

    NASA Astrophysics Data System (ADS)

    Ait-Sadoune, Idir; Ait-Ameur, Yamine

    We present a formal approach allowing to animate event B formal models. Invariants, deadlock freeness properties are expressed and proved on these models. This paper presents an approach that suggests to complete the proof activity in the event B method by animation activity. The obtained animator may be used to check if the event B models obtained fulfill user requirements, or to provide a help to the developer when describing its formal event B models and particularly in defining event B invariants and guards. More precisely, event B models are translated into data models expressed in the EXPRESS formal data modeling technique. The obtained data models are instantiated and provide an animation of the original B models. Following this approach, it becomes possible to trigger event B models, which themselves trigger entity instantiation on the EXPRESS side. As a further step, we show that the B models can be used as a monitoring system raising alarms in case of incorrect systems behavior. The proposed approach is operationally implemented in the B2EXPRESS tool which handles animation of event B models. It has been experimented for the validation of multimodal human interfaces in the context of VERBATIM project.

  17. Unified formalism for nonautonomous mechanical systems

    NASA Astrophysics Data System (ADS)

    Barbero-Liñán, María; Echeverría-Enríquez, Arturo; Diego, David Martín de; Muñoz-Lecanda, Miguel C.; Román-Roy, Narciso

    2008-06-01

    We present a unified geometric framework for describing both the Lagrangian and Hamiltonian formalisms of regular and nonregular time-dependent mechanical systems, which is based on the approach of Skinner and Rusk ["Generalized Hamiltonian dynamics I. Formulation on T*Q⊗TQ," J. Math. Phys. 24, 2589 (1983)]. The dynamical equations of motion and their compatibility and consistency are carefully studied, making clear that all the characteristics of the Lagrangian and the Hamiltonian formalisms are recovered in this formulation. As an example, a semidiscretization of the nonlinear wave equation is studied, proving the applicability of the proposed formalism.

  18. Generalized effective operator formalism for decaying systems

    NASA Astrophysics Data System (ADS)

    Paraschiv, Marius; Wölk, Sabine; Mannel, Thomas; Gühne, Otfried

    2016-10-01

    Systems of neutral kaons can be used to observe entanglement and the violation of Bell inequalities. The decay of these particles poses some problems, however, and recently an effective formalism for treating such systems has been derived. We generalize this formalism and make it applicable to other quantum systems that can be made to behave in a similar manner. As examples, we discuss two possible implementations of the generalized formalism using trapped ions such as 171Yb or 172Yb, which may be used to simulate kaonic behavior in a quantum optical system.

  19. From Livingstone to SMV: Formal Verification for Autonomous Spacecrafts

    NASA Technical Reports Server (NTRS)

    Pecheur, Charles; Simmons, Reid

    2000-01-01

    To fulfill the needs of its deep space exploration program, NASA is actively supporting research and development in autonomy software. However, the reliable and cost-effective development and validation of autonomy systems poses a tough challenge. Traditional scenario-based testing methods fall short because of the combinatorial explosion of possible situations to be analyzed, and formal verification techniques typically require a tedious, manual modelling by formal method experts. This paper presents the application of formal verification techniques in the development of autonomous controllers based on Livingstone, a model-based health-monitoring system that can detect and diagnose anomalies and suggest possible recovery actions. We present a translator that converts the models used by Livingstone into specifications that can be verified with the SMV model checker. The translation frees the Livingstone developer from the tedious conversion of his design to SMV, and isolates him from the technical details of the SMV program. We describe different aspects of the translation and briefly discuss its application to several NASA domains.

  20. Formal Requirements-Based Programming for Complex Systems

    NASA Technical Reports Server (NTRS)

    Rash, James L.; Hinchey, Michael G.; Rouff, Christopher A.; Gracanin, Denis

    2005-01-01

    Computer science as a field has not yet produced a general method to mechanically transform complex computer system requirements into a provably equivalent implementation. Such a method would be one major step towards dealing with complexity in computing, yet it remains the elusive holy grail of system development. Currently available tools and methods that start with a formal model of a system and mechanically produce a provably equivalent implementation are valuable but not sufficient. The gap that such tools and methods leave unfilled is that the formal models cannot be proven to be equivalent to the system requirements as originated by the customer For the classes of complex systems whose behavior can be described as a finite (but significant) set of scenarios, we offer a method for mechanically transforming requirements (expressed in restricted natural language, or appropriate graphical notations) into a provably equivalent formal model that can be used as the basis for code generation and other transformations. While other techniques are available, this method is unique in offering full mathematical tractability while using notations and techniques that are well known and well trusted. We illustrate the application of the method to an example procedure from the Hubble Robotic Servicing Mission currently under study and preliminary formulation at NASA Goddard Space Flight Center.

  1. A Formal Methods Approach to the Analysis of Mode Confusion

    NASA Technical Reports Server (NTRS)

    Butler, Ricky W.; Miller, Steven P.; Potts, James N.; Carreno, Victor A.

    2004-01-01

    The goal of the new NASA Aviation Safety Program (AvSP) is to reduce the civil aviation fatal accident rate by 80% in ten years and 90% in twenty years. This program is being driven by the accident data with a focus on the most recent history. Pilot error is the most commonly cited cause for fatal accidents (up to 70%) and obviously must be given major consideration in this program. While the greatest source of pilot error is the loss of situation awareness , mode confusion is increasingly becoming a major contributor as well. The January 30, 1995 issue of Aviation Week lists 184 incidents and accidents involving mode awareness including the Bangalore A320 crash 2/14/90, the Strasbourg A320 crash 1/20/92, the Mulhouse-Habsheim A320 crash 6/26/88, and the Toulouse A330 crash 6/30/94. These incidents and accidents reveal that pilots sometimes become confused about what the cockpit automation is doing. Consequently, human factors research is an obvious investment area. However, even a cursory look at the accident data reveals that the mode confusion problem is much deeper than just training deficiencies and a lack of human-oriented design. This is readily acknowledged by human factors experts. It seems that further progress in human factors must come through a deeper scrutiny of the internals of the automation. It is in this arena that formal methods can contribute. Formal methods refers to the use of techniques from logic and discrete mathematics in the specification, design, and verification of computer systems, both hardware and software. The fundamental goal of formal methods is to capture requirements, designs and implementations in a mathematically based model that can be analyzed in a rigorous manner. Research in formal methods is aimed at automating this analysis as much as possible. By capturing the internal behavior of a flight deck in a rigorous and detailed formal model, the dark corners of a design can be analyzed. This paper will explore how formal

  2. Properties of a Formal Method for Prediction of Emergent Behaviors in Swarm-based Systems

    NASA Technical Reports Server (NTRS)

    Rouff, Christopher; Vanderbilt, Amy; Hinchey, Mike; Truszkowski, Walt; Rash, James

    2004-01-01

    Autonomous intelligent swarms of satellites are being proposed for NASA missions that have complex behaviors and interactions. The emergent properties of swarms make these missions powerful, but at the same time more difficult to design and assure that proper behaviors will emerge. This paper gives the results of research into formal methods techniques for verification and validation of NASA swarm-based missions. Multiple formal methods were evaluated to determine their effectiveness in modeling and assuring the behavior of swarms of spacecraft. The NASA ANTS mission was used as an example of swarm intelligence for which to apply the formal methods. This paper will give the evaluation of these formal methods and give partial specifications of the ANTS mission using four selected methods. We then give an evaluation of the methods and the needed properties of a formal method for effective specification and prediction of emergent behavior in swarm-based systems.

  3. On the Formal Verification of Conflict Detection Algorithms

    NASA Technical Reports Server (NTRS)

    Munoz, Cesar; Butler, Ricky W.; Carreno, Victor A.; Dowek, Gilles

    2001-01-01

    Safety assessment of new air traffic management systems is a main issue for civil aviation authorities. Standard techniques such as testing and simulation have serious limitations in new systems that are significantly more autonomous than the older ones. In this paper, we present an innovative approach, based on formal verification, for establishing the correctness of conflict detection systems. Fundamental to our approach is the concept of trajectory, which is a continuous path in the x-y plane constrained by physical laws and operational requirements. From the Model of trajectories, we extract, and formally prove, high level properties that can serve as a framework to analyze conflict scenarios. We use the Airborne Information for Lateral Spacing (AILS) alerting algorithm as a case study of our approach.

  4. Application of Lightweight Formal Methods to Software Security

    NASA Technical Reports Server (NTRS)

    Gilliam, David P.; Powell, John D.; Bishop, Matt

    2005-01-01

    Formal specification and verification of security has proven a challenging task. There is no single method that has proven feasible. Instead, an integrated approach which combines several formal techniques can increase the confidence in the verification of software security properties. Such an approach which species security properties in a library that can be reused by 2 instruments and their methodologies developed for the National Aeronautics and Space Administration (NASA) at the Jet Propulsion Laboratory (JPL) are described herein The Flexible Modeling Framework (FMF) is a model based verijkation instrument that uses Promela and the SPIN model checker. The Property Based Tester (PBT) uses TASPEC and a Text Execution Monitor (TEM). They are used to reduce vulnerabilities and unwanted exposures in software during the development and maintenance life cycles.

  5. Formal Methods for Automated Diagnosis of Autosub 6000

    NASA Technical Reports Server (NTRS)

    Ernits, Juhan; Dearden, Richard; Pebody, Miles

    2009-01-01

    This is a progress report on applying formal methods in the context of building an automated diagnosis and recovery system for Autosub 6000, an Autonomous Underwater Vehicle (AUV). The diagnosis task involves building abstract models of the control system of the AUV. The diagnosis engine is based on Livingstone 2, a model-based diagnoser originally built for aerospace applications. Large parts of the diagnosis model can be built without concrete knowledge about each mission, but actual mission scripts and configuration parameters that carry important information for diagnosis are changed for every mission. Thus we use formal methods for generating the mission control part of the diagnosis model automatically from the mission script and perform a number of invariant checks to validate the configuration. After the diagnosis model is augmented with the generated mission control component model, it needs to be validated using verification techniques.

  6. Why Engineers Should Consider Formal Methods

    NASA Technical Reports Server (NTRS)

    Holloway, C. Michael

    1997-01-01

    This paper presents a logical analysis of a typical argument favoring the use of formal methods for software development, and suggests an alternative argument that is simpler and stronger than the typical one.

  7. Differences between Formal and Informal Communicative Channels.

    ERIC Educational Resources Information Center

    Johnson, J. David; And Others

    1994-01-01

    Compares formal and informal organizational communication structures within a large, technically oriented midwestern state governmental agency, specifically focusing on salience, channel factors, and channel usage. Suggests that informal channels in this organization were more highly evaluated in general. (SR)

  8. Importance of Reversibility in the Quantum Formalism

    NASA Astrophysics Data System (ADS)

    David, François

    2011-10-01

    In this Letter I stress the role of causal reversibility (time symmetry), together with causality and locality, in the justification of the quantum formalism. First, in the algebraic quantum formalism, I show that the assumption of reversibility implies that the observables of a quantum theory form an abstract real C⋆ algebra, and can be represented as an algebra of operators on a real Hilbert space. Second, in the quantum logic formalism, I emphasize which axioms for the lattice of propositions (the existence of an orthocomplementation and the covering property) derive from reversibility. A new argument based on locality and Soler’s theorem is used to derive the representation as projectors on a regular Hilbert space from the general quantum logic formalism. In both cases it is recalled that the restriction to complex algebras and Hilbert spaces comes from the constraints of locality and separability.

  9. Transitions from Formal Education to the Workplace

    ERIC Educational Resources Information Center

    Olson, Joann S.

    2014-01-01

    This chapter frames the transition to adulthood in the context of the moving from formal educational settings to the often less-structured learning that occurs in workplace settings. Although schooling may end, learning continues.

  10. The adolescent personality, formal reasoning, and values.

    PubMed

    Darmody, J P

    1991-01-01

    This study examined the relationship between levels of Piagetian formal reasoning ability and values preferences derived from the Rokeach Value Survey. The subjects were 448 secondary school students (mean age = 16.25 years). The results of the study were consistent with predictions about the likely changes in value rankings as formal reasoning ability develops. Subjects with high scores on formal reasoning ranked terminal values representing abstract notions with long-term implications higher than those focusing on immediate gratification. They also favored the instrumental values of self-reliance, competence, and independence. Low scorers on formal reasoning showed a preference for value groupings which were personal, hedonistic, and involved immediate gratification and social approval. PMID:1962555

  11. Formal Instruction in Dental Professional Ethics.

    ERIC Educational Resources Information Center

    Ozar, David T.

    1985-01-01

    Three common arguments against formal classes in professional ethics are examined. A minimum curriculum in dental professional ethics is proposed and a proposed program in professional ethics in dentistry is appended. (MLW)

  12. Open systems & non-formal education

    NASA Astrophysics Data System (ADS)

    Wheeler, Gerald F.

    1988-10-01

    Professor Dib created an important structure that can be used to attach the many and various activities that fall in the category of this title. While I plan to use his structure, I will be emphasizing a different component of his spectrum and promoting a different need. Professor Dib suggested a critical need to move our teaching styles away from formal modes to non-formal modes of delivery. I suggest an equally critical need in the area of informal education. And, I will propose aways to move us toward the same goal, non-formal activities. I believe we need to find ways to use the many informal education activities that occur almost automatically in our societies to move our potential learners to richer non-formal endeavors. Both needs are real; both activities are valid.

  13. Experiences Using Formal Methods for Requirements Modeling

    NASA Technical Reports Server (NTRS)

    Easterbrook, Steve; Lutz, Robyn; Covington, Rick; Kelly, John; Ampo, Yoko; Hamilton, David

    1996-01-01

    This paper describes three cases studies in the lightweight application of formal methods to requirements modeling for spacecraft fault protection systems. The case studies differ from previously reported applications of formal methods in that formal methods were applied very early in the requirements engineering process, to validate the evolving requirements. The results were fed back into the projects, to improve the informal specifications. For each case study, we describe what methods were applied, how they were applied, how much effort was involved, and what the findings were. In all three cases, the formal modeling provided a cost effective enhancement of the existing verification and validation processes. We conclude that the benefits gained from early modeling of unstable requirements more than outweigh the effort needed to maintain multiple representations.

  14. General formalism for singly thermostated Hamiltonian dynamics

    NASA Astrophysics Data System (ADS)

    Ramshaw, John D.

    2015-11-01

    A general formalism is developed for constructing modified Hamiltonian dynamical systems which preserve a canonical equilibrium distribution by adding a time evolution equation for a single additional thermostat variable. When such systems are ergodic, canonical ensemble averages can be computed as dynamical time averages over a single trajectory. Systems of this type were unknown until their recent discovery by Hoover and colleagues. The present formalism should facilitate the discovery, construction, and classification of other such systems by encompassing a wide class of them within a single unified framework. This formalism includes both canonical and generalized Hamiltonian systems in a state space of arbitrary dimensionality (either even or odd) and therefore encompasses both few- and many-particle systems. Particular attention is devoted to the physical motivation and interpretation of the formalism, which largely determine its structure. An analogy to stochastic thermostats and fluctuation-dissipation theorems is briefly discussed.

  15. Formal specification of human-computer interfaces

    NASA Technical Reports Server (NTRS)

    Auernheimer, Brent

    1990-01-01

    A high-level formal specification of a human computer interface is described. Previous work is reviewed and the ASLAN specification language is described. Top-level specifications written in ASLAN for a library and a multiwindow interface are discussed.

  16. Elements of (Super-)Hamiltonian Formalism

    NASA Astrophysics Data System (ADS)

    Nersessian, A.

    In these lectures we discuss some basic aspects of Hamiltonian formalism, which usually do not appear in standard textbooks on classical mechanics for physicists. We pay special attention to the procedure of Hamiltonian reduction illustrating it by the examples related to Hopf maps. Then we briefly discuss the supergeneralization(s) of the Hamiltonian formalism and present some simple models of supersymmetric mechanics on Kähler manifolds.

  17. Closed terminologies in description logics

    SciTech Connect

    Weida, R.A. |

    1996-12-31

    We introduce a predictive concept recognition methodology for description logics based on a new closed terminology assumption. During knowledge engineering, our system adopts the standard open terminology assumption as it automatically classifies concept descriptions into a taxonomy via subsumption inferences. However, for applications like configuration, the terminology becomes fixed during problem solving. Then, closed terminology reasoning is more appropriate. In our interactive configuration application, a user incrementally specifies an individual computer system in collaboration with a configuration engine. Choices can be made in any order and at any level of abstraction. We distinguish between abstract and concrete concepts to formally define when an individual`s description may be considered finished. We also take advantage of the closed terminology assumption, together with the terminology`s subsumption-based organization, to efficiently track the types of systems and components consistent with current choices, infer additional constraints on current choices, and appropriately guide future choices. Thus, we can help focus the efforts of both user and configuration engine.

  18. A Survey of Formal Methods for Intelligent Swarms

    NASA Technical Reports Server (NTRS)

    Truszkowski, Walt; Rash, James; Hinchey, Mike; Rouff, Chrustopher A.

    2004-01-01

    cutting edge in system correctness, and requires higher levels of assurance than other (traditional) missions that use a single or small number of spacecraft that are deterministic in nature and have near continuous communication access. One of the highest possible levels of assurance comes from the application of formal methods. Formal methods are mathematics-based tools and techniques for specifying and verifying (software and hardware) systems. They are particularly useful for specifying complex parallel systems, such as exemplified by the ANTS mission, where the entire system is difficult for a single person to fully understand, a problem that is multiplied with multiple developers. Once written, a formal specification can be used to prove properties of a system (e.g., the underlying system will go from one state to another or not into a specific state) and check for particular types of errors (e.g., race or livelock conditions). A formal specification can also be used as input to a model checker for further validation. This report gives the results of a survey of formal methods techniques for verification and validation of space missions that use swarm technology. Multiple formal methods were evaluated to determine their effectiveness in modeling and assuring the behavior of swarms of spacecraft using the ANTS mission as an example system. This report is the first result of the project to determine formal approaches that are promising for formally specifying swarm-based systems. From this survey, the most promising approaches were selected and are discussed relative to their possible application to the ANTS mission. Future work will include the application of an integrated approach, based on the selected approaches identified in this report, to the formal specification of the ANTS mission.

  19. Increasing patient safety and efficiency in transfusion therapy using formal process definitions.

    PubMed

    Henneman, Elizabeth A; Avrunin, George S; Clarke, Lori A; Osterweil, Leon J; Andrzejewski, Chester; Merrigan, Karen; Cobleigh, Rachel; Frederick, Kimberly; Katz-Bassett, Ethan; Henneman, Philip L

    2007-01-01

    The administration of blood products is a common, resource-intensive, and potentially problem-prone area that may place patients at elevated risk in the clinical setting. Much of the emphasis in transfusion safety has been targeted toward quality control measures in laboratory settings where blood products are prepared for administration as well as in automation of certain laboratory processes. In contrast, the process of transfusing blood in the clinical setting (ie, at the point of care) has essentially remained unchanged over the past several decades. Many of the currently available methods for improving the quality and safety of blood transfusions in the clinical setting rely on informal process descriptions, such as flow charts and medical algorithms, to describe medical processes. These informal descriptions, although useful in presenting an overview of standard processes, can be ambiguous or incomplete. For example, they often describe only the standard process and leave out how to handle possible failures or exceptions. One alternative to these informal descriptions is to use formal process definitions, which can serve as the basis for a variety of analyses because these formal definitions offer precision in the representation of all possible ways that a process can be carried out in both standard and exceptional situations. Formal process definitions have not previously been used to describe and improve medical processes. The use of such formal definitions to prospectively identify potential error and improve the transfusion process has not previously been reported. The purpose of this article is to introduce the concept of formally defining processes and to describe how formal definitions of blood transfusion processes can be used to detect and correct transfusion process errors in ways not currently possible using existing quality improvement methods.

  20. Interacting boson model descriptions of high-spin states

    SciTech Connect

    Kuyucak, S.

    1995-10-01

    The I/N expansion technique for the interacting boson model (IBM) has recently been extended to higher orders using computer algebra. This allows, for the first time, a realistic description of high-spin states in the framework of the sdg-IBM. Systematic studies of moment of inertia show that the problems with its spin dependence are due to the energy surface being too rigid against rotations which can be remedied by including the d-boson energy in the Hamiltonian. The d-boson energy is also instrumental in resolving two other problems in the IBM first raised by Bohr and Mottelson, namely, energy scale mismatch in the ground and gamma bands, and the boson cutoff in B(E2) values. We apply the results to describe the high-spin states in rare-earth and actinide nuclei where the ground band has been followed up to spins L=30, and hence provide unique test cases for collective models. The same formalism can also be used in a phenomenological description of superdeformed states as will be demonstrated with examples in the Hg-Pb region.

  1. Properties of a Formal Method to Model Emergence in Swarm-Based Systems

    NASA Technical Reports Server (NTRS)

    Rouff, Christopher; Vanderbilt, Amy; Truszkowski, Walt; Rash, James; Hinchey, Mike

    2004-01-01

    Future space missions will require cooperation between multiple satellites and/or rovers. Developers are proposing intelligent autonomous swarms for these missions, but swarm-based systems are difficult or impossible to test with current techniques. This viewgraph presentation examines the use of formal methods in testing swarm-based systems. The potential usefulness of formal methods in modeling the ANTS asteroid encounter mission is also examined.

  2. Report on the formal specification and partial verification of the VIPER microprocessor

    NASA Technical Reports Server (NTRS)

    Brock, Bishop; Hunt, Warren A., Jr.

    1991-01-01

    The formal specification and partial verification of the VIPER microprocessor is reviewed. The VIPER microprocessor was designed by RSRE, Malvern, England, for safety critical computing applications (e.g., aircraft, reactor control, medical instruments, armaments). The VIPER was carefully specified and partially verified in an attempt to provide a microprocessor with completely predictable operating characteristics. The specification of VIPER is divided into several levels of abstraction, from a gate-level description up to an instruction execution model. Although the consistency between certain levels was demonstrated with mechanically-assisted mathematical proof, the formal verification of VIPER was never completed.

  3. Classical and quantum-mechanical axioms with the higher time derivative formalism

    NASA Astrophysics Data System (ADS)

    Kamalov, Timur

    2013-06-01

    A Newtonian mechanics model is essentially the model of a point body in an inertial reference frame. How to describe extended bodies in non-inertial (vibration) reference frames with the random initial conditions? One of the most generalized ways of descriptions (known as the higher derivatives formalism) consists in taking into account the infinite number of the higher temporal derivatives of the coordinates in the Lagrange function. Such formalism describing physical objects in the infinite dimensions space does not contradict to the quantum mechanics and infinite dimensions Hilbert space.

  4. Interval Predictor Models with a Formal Characterization of Uncertainty and Reliability

    NASA Technical Reports Server (NTRS)

    Crespo, Luis G.; Giesy, Daniel P.; Kenny, Sean P.

    2014-01-01

    This paper develops techniques for constructing empirical predictor models based on observations. By contrast to standard models, which yield a single predicted output at each value of the model's inputs, Interval Predictors Models (IPM) yield an interval into which the unobserved output is predicted to fall. The IPMs proposed prescribe the output as an interval valued function of the model's inputs, render a formal description of both the uncertainty in the model's parameters and of the spread in the predicted output. Uncertainty is prescribed as a hyper-rectangular set in the space of model's parameters. The propagation of this set through the empirical model yields a range of outputs of minimal spread containing all (or, depending on the formulation, most) of the observations. Optimization-based strategies for calculating IPMs and eliminating the effects of outliers are proposed. Outliers are identified by evaluating the extent by which they degrade the tightness of the prediction. This evaluation can be carried out while the IPM is calculated. When the data satisfies mild stochastic assumptions, and the optimization program used for calculating the IPM is convex (or, when its solution coincides with the solution to an auxiliary convex program), the model's reliability (that is, the probability that a future observation would be within the predicted range of outputs) can be bounded rigorously by a non-asymptotic formula.

  5. Optical simulation of photovoltaic modules with multiple textured interfaces using the matrix-based formalism OPTOS.

    PubMed

    Tucher, Nico; Eisenlohr, Johannes; Gebrewold, Habtamu; Kiefel, Peter; Höhn, Oliver; Hauser, Hubert; Goldschmidt, Jan Christoph; Bläsi, Benedikt

    2016-07-11

    The OPTOS formalism is a matrix-based approach to determine the optical properties of textured optical sheets. It is extended within this work to enable the modelling of systems with an arbitrary number of textured, plane-parallel interfaces. A matrix-based system description is derived that accounts for the optical reflection and transmission interaction between all textured interfaces. Using OPTOS, we calculate reflectance and absorptance of complete photovoltaic module stacks, which consist of encapsulated silicon solar cells featuring textures that operate in different optical regimes. As exemplary systems, solar cells with and without module encapsulation are shown to exhibit a considerable absorptance gain if the random pyramid front side texture is combined with a diffractive rear side grating. A variation of the sunlight's angle of incidence reveals that the grating gain is almost not affected for incoming polar angles up to 60°. Considering as well the good agreement with alternative simulation techniques, OPTOS is demonstrated to be a versatile and efficient method for the optical analysis of photovoltaic modules. PMID:27410896

  6. Optical simulation of photovoltaic modules with multiple textured interfaces using the matrix-based formalism OPTOS.

    PubMed

    Tucher, Nico; Eisenlohr, Johannes; Gebrewold, Habtamu; Kiefel, Peter; Höhn, Oliver; Hauser, Hubert; Goldschmidt, Jan Christoph; Bläsi, Benedikt

    2016-07-11

    The OPTOS formalism is a matrix-based approach to determine the optical properties of textured optical sheets. It is extended within this work to enable the modelling of systems with an arbitrary number of textured, plane-parallel interfaces. A matrix-based system description is derived that accounts for the optical reflection and transmission interaction between all textured interfaces. Using OPTOS, we calculate reflectance and absorptance of complete photovoltaic module stacks, which consist of encapsulated silicon solar cells featuring textures that operate in different optical regimes. As exemplary systems, solar cells with and without module encapsulation are shown to exhibit a considerable absorptance gain if the random pyramid front side texture is combined with a diffractive rear side grating. A variation of the sunlight's angle of incidence reveals that the grating gain is almost not affected for incoming polar angles up to 60°. Considering as well the good agreement with alternative simulation techniques, OPTOS is demonstrated to be a versatile and efficient method for the optical analysis of photovoltaic modules.

  7. DESCRIPTIVE ANALYSIS OF DIVALENT SALTS

    PubMed Central

    YANG, HEIDI HAI-LING; LAWLESS, HARRY T.

    2005-01-01

    Many divalent salts (e.g., calcium, iron, zinc), have important nutritional value and are used to fortify food or as dietary supplements. Sensory characterization of some divalent salts in aqueous solutions by untrained judges has been reported in the psychophysical literature, but formal sensory evaluation by trained panels is lacking. To provide this information, a trained descriptive panel evaluated the sensory characteristics of 10 divalent salts including ferrous sulfate, chloride and gluconate; calcium chloride, lactate and glycerophosphate; zinc sulfate and chloride; and magnesium sulfate and chloride. Among the compounds tested, iron compounds were highest in metallic taste; zinc compounds had higher astringency and a glutamate-like sensation; and bitterness was pronounced for magnesium and calcium salts. Bitterness was affected by the anion in ferrous and calcium salts. Results from the trained panelists were largely consistent with the psychophysical literature using untrained judges, but provided a more comprehensive set of oral sensory attributes. PMID:16614749

  8. Quantum interference within the complex quantum Hamilton-Jacobi formalism

    SciTech Connect

    Chou, Chia-Chun; Sanz, Angel S.; Miret-Artes, Salvador; Wyatt, Robert E.

    2010-10-15

    Quantum interference is investigated within the complex quantum Hamilton-Jacobi formalism. As shown in a previous work [Phys. Rev. Lett. 102 (2009) 250401], complex quantum trajectories display helical wrapping around stagnation tubes and hyperbolic deflection near vortical tubes, these structures being prominent features of quantum caves in space-time Argand plots. Here, we further analyze the divergence and vorticity of the quantum momentum function along streamlines near poles, showing the intricacy of the complex dynamics. Nevertheless, despite this behavior, we show that the appearance of the well-known interference features (on the real axis) can be easily understood in terms of the rotation of the nodal line in the complex plane. This offers a unified description of interference as well as an elegant and practical method to compute the lifetime for interference features, defined in terms of the average wrapping time, i.e., considering such features as a resonant process.

  9. Formal versus heuristic modeling for multitarget Bayes filtering

    NASA Astrophysics Data System (ADS)

    Mahler, Ronald P. S.

    2004-08-01

    The multisensor-multitarget Bayes filter is the foundation for multi-sensor-multitarget detection, tracking, and identification. This paper addresses the question of principled implementation of this filter. Algorithms can always be cobbled together using catch-as-catch-can heuristic techniques. In formal Bayes modeling one instead derives statistically precise, implementation-independent equations from which principle approximations can then be derived. Indeed, this has become the accepted methodology for single-sensor, single-target tracking R&D. In the case of the multitarget filter, however, partisans of a so-called "plain-vanilla Bayesian approach" have disparaged formal Bayes modelling, and have protrayed specific, ad hoc implementations as completely general, "powerful and robust computational methods." In this and a companion paper I expose the speciousness of such claims. This paper reviews the elements of formal Bayes modeling and approximation, describes what they must look like in the multitarget case, and contrasts them with the "plain-vanilla Bayesian approach."

  10. An Integrated Environment for Efficient Formal Design and Verification

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The general goal of this project was to improve the practicality of formal methods by combining techniques from model checking and theorem proving. At the time the project was proposed, the model checking and theorem proving communities were applying different tools to similar problems, but there was not much cross-fertilization. This project involved a group from SRI that had substantial experience in the development and application of theorem-proving technology, and a group at Stanford that specialized in model checking techniques. Now, over five years after the proposal was submitted, there are many research groups working on combining theorem-proving and model checking techniques, and much more communication between the model checking and theorem proving research communities. This project contributed significantly to this research trend. The research work under this project covered a variety of topics: new theory and algorithms; prototype tools; verification methodology; and applications to problems in particular domains.

  11. Formal modeling of robot behavior with learning.

    PubMed

    Kirwan, Ryan; Miller, Alice; Porr, Bernd; Di Prodi, P

    2013-11-01

    We present formal specification and verification of a robot moving in a complex network, using temporal sequence learning to avoid obstacles. Our aim is to demonstrate the benefit of using a formal approach to analyze such a system as a complementary approach to simulation. We first describe a classical closed-loop simulation of the system and compare this approach to one in which the system is analyzed using formal verification. We show that the formal verification has some advantages over classical simulation and finds deficiencies our classical simulation did not identify. Specifically we present a formal specification of the system, defined in the Promela modeling language and show how the associated model is verified using the Spin model checker. We then introduce an abstract model that is suitable for verifying the same properties for any environment with obstacles under a given set of assumptions. We outline how we can prove that our abstraction is sound: any property that holds for the abstracted model will hold in the original (unabstracted) model.

  12. Formal Methods Case Studies for DO-333

    NASA Technical Reports Server (NTRS)

    Cofer, Darren; Miller, Steven P.

    2014-01-01

    RTCA DO-333, Formal Methods Supplement to DO-178C and DO-278A provides guidance for software developers wishing to use formal methods in the certification of airborne systems and air traffic management systems. The supplement identifies the modifications and additions to DO-178C and DO-278A objectives, activities, and software life cycle data that should be addressed when formal methods are used as part of the software development process. This report presents three case studies describing the use of different classes of formal methods to satisfy certification objectives for a common avionics example - a dual-channel Flight Guidance System. The three case studies illustrate the use of theorem proving, model checking, and abstract interpretation. The material presented is not intended to represent a complete certification effort. Rather, the purpose is to illustrate how formal methods can be used in a realistic avionics software development project, with a focus on the evidence produced that could be used to satisfy the verification objectives found in Section 6 of DO-178C.

  13. Formal representation of 3D structural geological models

    NASA Astrophysics Data System (ADS)

    Wang, Zhangang; Qu, Honggang; Wu, Zixing; Yang, Hongjun; Du, Qunle

    2016-05-01

    The development and widespread application of geological modeling methods has increased demands for the integration and sharing services of three dimensional (3D) geological data. However, theoretical research in the field of geological information sciences is limited despite the widespread use of Geographic Information Systems (GIS) in geology. In particular, fundamental research on the formal representations and standardized spatial descriptions of 3D structural models is required. This is necessary for accurate understanding and further applications of geological data in 3D space. In this paper, we propose a formal representation method for 3D structural models using the theory of point set topology, which produces a mathematical definition for the major types of geological objects. The spatial relationships between geologic boundaries, structures, and units are explained in detail using the 9-intersection model. Reasonable conditions for describing the topological space of 3D structural models are also provided. The results from this study can be used as potential support for the standardized representation and spatial quality evaluation of 3D structural models, as well as for specific needs related to model-based management, query, and analysis.

  14. Developing Formal Correctness Properties from Natural Language Requirements

    NASA Technical Reports Server (NTRS)

    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.

  15. Formal Verification for a Next-Generation Space Shuttle

    NASA Technical Reports Server (NTRS)

    Nelson, Stacy D.; Pecheur, Charles; Koga, Dennis (Technical Monitor)

    2002-01-01

    This paper discusses the verification and validation (V&2) of advanced software used for integrated vehicle health monitoring (IVHM), in the context of NASA's next-generation space shuttle. We survey the current VBCV practice and standards used in selected NASA projects, review applicable formal verification techniques, and discuss their integration info existing development practice and standards. We also describe two verification tools, JMPL2SMV and Livingstone PathFinder, that can be used to thoroughly verify diagnosis applications that use model-based reasoning, such as the Livingstone system.

  16. The Nation's Needs in Aviation Formal Methods

    NASA Technical Reports Server (NTRS)

    Pritchett, Amy R.

    2008-01-01

    Aviation, both on-board systems and the National Airspace System, can be transformed by many current and future technical capabilities. To name but a few, improved efficiency may be achieved by integrating functions; robustness may be improved by distributing functions; and safety may be improved by building in risk mitigation through not only redundant, independent systems but also through operational concepts and effective interaction with human operators. This talk will review the key aspects of verification, validation and certification for which formal methods will provide a critical function in enabling truly revolutionary designs to enter the operational community, illustrating successes in formal modeling to date and posing further questions for the formal modeling community.

  17. Formalizing Darwinism and inclusive fitness theory.

    PubMed

    Grafen, Alan

    2009-11-12

    Inclusive fitness maximization is a basic building block for biological contributions to any theory of the evolution of society. There is a view in mathematical population genetics that nothing is caused to be maximized in the process of natural selection, but this is explained as arising from a misunderstanding about the meaning of fitness maximization. Current theoretical work on inclusive fitness is discussed, with emphasis on the author's 'formal Darwinism project'. Generally, favourable conclusions are drawn about the validity of assuming fitness maximization, but the need for continuing work is emphasized, along with the possibility that substantive exceptions may be uncovered. The formal Darwinism project aims more ambitiously to represent in a formal mathematical framework the central point of Darwin's Origin of Species, that the mechanical processes of inheritance and reproduction can give rise to the appearance of design, and it is a fitting ambition in Darwin's bicentenary year to capture his most profound discovery in the lingua franca of science.

  18. User Interface Technology for Formal Specification Development

    NASA Technical Reports Server (NTRS)

    Lowry, Michael; Philpot, Andrew; Pressburger, Thomas; Underwood, Ian; Lum, Henry, Jr. (Technical Monitor)

    1994-01-01

    Formal specification development and modification are an essential component of the knowledge-based software life cycle. User interface technology is needed to empower end-users to create their own formal specifications. This paper describes the advanced user interface for AMPHION1 a knowledge-based software engineering system that targets scientific subroutine libraries. AMPHION is a generic, domain-independent architecture that is specialized to an application domain through a declarative domain theory. Formal specification development and reuse is made accessible to end-users through an intuitive graphical interface that provides semantic guidance in creating diagrams denoting formal specifications in an application domain. The diagrams also serve to document the specifications. Automatic deductive program synthesis ensures that end-user specifications are correctly implemented. The tables that drive AMPHION's user interface are automatically compiled from a domain theory; portions of the interface can be customized by the end-user. The user interface facilitates formal specification development by hiding syntactic details, such as logical notation. It also turns some of the barriers for end-user specification development associated with strongly typed formal languages into active sources of guidance, without restricting advanced users. The interface is especially suited for specification modification. AMPHION has been applied to the domain of solar system kinematics through the development of a declarative domain theory. Testing over six months with planetary scientists indicates that AMPHION's interactive specification acquisition paradigm enables users to develop, modify, and reuse specifications at least an order of magnitude more rapidly than manual program development.

  19. Combining Formal, Non-Formal and Informal Learning for Workforce Skill Development

    ERIC Educational Resources Information Center

    Misko, Josie

    2008-01-01

    This literature review, undertaken for Australian Industry Group, shows how multiple variations and combinations of formal, informal and non-formal learning, accompanied by various government incentives and organisational initiatives (including job redesign, cross-skilling, multi-skilling, diversified career pathways, action learning projects,…

  20. The Interrelatedness of Formal, Non-Formal and Informal Learning: Evidence from Labour Market Program Participants

    ERIC Educational Resources Information Center

    Cameron, Roslyn; Harrison, Jennifer L.

    2012-01-01

    Definitions, differences and relationships between formal, non-formal and informal learning have long been contentious. There has been a significant change in language and reference from adult education to what amounts to forms of learning categorised by their modes of facilitation. Nonetheless, there is currently a renewed interest in the…

  1. Formal and Non-Formal Digital Practices: Institutionalizing Transactional Learning Spaces in a Media Classroom

    ERIC Educational Resources Information Center

    de Lange, Thomas

    2011-01-01

    This article examines how a classroom procedure known as PGE (Plan/Go-through/Evaluate) group work aims at integrating formal and non-formal media experiences and practices into classroom-based media learning. The study displays, on the one hand, how PGE group work emerged and was institutionally embedded in a media course. On the other hand, the…

  2. The Comparative Functionality of Formal and Non-Formal Education for Women: Final Report.

    ERIC Educational Resources Information Center

    Derryck, Vivian Lowery

    This final report describes a five-phase study to ascertain whether formal or non-formal education has the greater functionality to accelerate women's integration into development activities. Part 1 (two chapters), introduction and background, defines the problem, sets parameters of the study, and provides definitions of education terms. Part 2…

  3. Extending the ADM formalism to Weyl geometry

    NASA Astrophysics Data System (ADS)

    Barreto, A. B.; Almeida, T. S.; Romero, C.

    2015-03-01

    In order to treat quantum cosmology in the framework of Weyl spacetimes we take the first step of extending the Arnowitt-Deser-Misner formalism to Weyl geometry. We then obtain an expression of the curvature tensor in terms of spatial quantities by splitting spacetime in (3+l)-dimensional form. We next write the Lagrangian of the gravitation field based in Weyl-type gravity theory. We extend the general relativistic formalism in such a way that it can be applied to investigate the quantum cosmology of models whose spacetimes are endowed with a Weyl geometrical structure.

  4. Educación no formal

    NASA Astrophysics Data System (ADS)

    Tignanelli, H.

    Se comentan en esta comunicación, las principales contribuciones realizadas en el campo de la educación en astronomía en los niveles primario, secundario y terciario, como punto de partida para la discusión de la actual inserción de los contenidos astronómicos en los nuevos contenidos curriculares de la EGB - Educación General Básica- y Polimodal, de la Reforma Educativa. En particular, se discuten los alcances de la educación formal y no formal, su importancia para la capacitación de profesores y maestros, y perspectivas a futuro.

  5. Extending the ADM formalism to Weyl geometry

    SciTech Connect

    Barreto, A. B.; Almeida, T. S.; Romero, C.

    2015-03-26

    In order to treat quantum cosmology in the framework of Weyl spacetimes we take the first step of extending the Arnowitt-Deser-Misner formalism to Weyl geometry. We then obtain an expression of the curvature tensor in terms of spatial quantities by splitting spacetime in (3+l)-dimensional form. We next write the Lagrangian of the gravitation field based in Weyl-type gravity theory. We extend the general relativistic formalism in such a way that it can be applied to investigate the quantum cosmology of models whose spacetimes are endowed with a Weyl geometrical structure.

  6. Simultaneous Measurement of Tracer and Interdiffusion Coefficients: An Isotopic Phenomenological Diffusion Formalism for the Binary Alloy

    SciTech Connect

    Belova, Irina; Kulkarni, Nagraj S; Sohn, Yong Ho; Murch, Prof. Graeme

    2013-01-01

    In this paper, a new development of the classic Onsager phenomenological formalism is derived using relations based on linear response theory. The development concerns the correct description of the fluxes of the atomic isotopes. The resulting expressions in the laboratory frame are surprisingly simple and consist of terms coming from the standard interdiffusion expressions and from Fick s first law where the tracer diffusion coefficient is involved thus providing a better understanding of the relationship between the two approaches - Fick s first law and the Onsager phenomenological formalism. From an experimental application perspective, the new development is applied to the binary alloy case. The formalism provides the means to obtain the interdiffusion coefficient and tracer diffusion coefficients simultaneously from analysis of the interdiffusion concentration profiles in a single experiment.

  7. Developmental trauma disorder: pros and cons of including formal criteria in the psychiatric diagnostic systems

    PubMed Central

    2013-01-01

    Background This article reviews the current debate on developmental trauma disorder (DTD) with respect to formalizing its diagnostic criteria. Victims of abuse, neglect, and maltreatment in childhood often develop a wide range of age-dependent psychopathologies with various mental comorbidities. The supporters of a formal DTD diagnosis argue that post-traumatic stress disorder (PTSD) does not cover all consequences of severe and complex traumatization in childhood. Discussion Traumatized individuals are difficult to treat, but clinical experience has shown that they tend to benefit from specific trauma therapy. A main argument against inclusion of formal DTD criteria into existing diagnostic systems is that emphasis on the etiology of the disorder might force current diagnostic systems to deviate from their purely descriptive nature. Furthermore, comorbidities and biological aspects of the disorder may be underdiagnosed using the DTD criteria. Summary Here, we discuss arguments for and against the proposal of DTD criteria and address implications and consequences for the clinical practice. PMID:23286319

  8. Formal consensus: the development of a national clinical guideline

    PubMed Central

    Rycroft-Malone, J

    2001-01-01

    Background—There is currently a political enthusiasm for the development and use of clinical guidelines despite, paradoxically, there being relatively few healthcare issues that have a sound research evidence base. As decisions have to be made even where there is an undetermined evidence base and that limiting recommendations to where evidence exists may reduce the scope of guidelines, thus limiting their value to practitioners, guideline developers have to rely on various different sources of evidence and adapt their methods accordingly. This paper outlines a method for guideline development which incorporates a consensus process devised to tackle the challenges of a variable research evidence base for the development of a national clinical guideline on risk assessment and prevention of pressure ulcers. Method—To inform the recommendations of the guideline a formal consensus process based on a nominal group technique was used to incorporate three strands of evidence: research, clinical expertise, and patient experience. Results—The recommendations for this guideline were derived directly from the statements agreed in the formal consensus process and from key evidence-based findings from the systematic reviews. The existing format of the statements that participants had rated allowed a straightforward revision to "active" recommendations, thus reducing further risk of subjectivity entering into the process. Conclusions—The method outlined proved to be a practical and systematic way of integrating a number of different evidence sources. The resultant guideline is a mixture of research based and consensus based recommendations. Given the lack of available guidance on how to mix research with expert opinion and patient experiences, the method used for the development of this guideline has been outlined so that other guideline developers may use, adapt, and test it further. Key Words: guidelines; guideline development; formal consensus process; nominal group

  9. Formal Synthesis of (±)-Roseophilin

    PubMed Central

    Bitar, Abdallah Y.; Frontier, Alison J.

    2009-01-01

    A formal synthesis of (±)-roseophilin is described. Scandium(III)-catalyzed Nazarov cyclization of 2,5-disubstituted N-tosylpyrrole 19 gives a 5,5’-fused ketopyrrole, and ansa-bridge formation via π-allyl palladium macrocyclization gives 21. PMID:19053717

  10. The Transition to Formal Thinking in Mathematics

    ERIC Educational Resources Information Center

    Tall, David

    2008-01-01

    This paper focuses on the changes in thinking involved in the transition from school mathematics to formal proof in pure mathematics at university. School mathematics is seen as a combination of visual representations, including geometry and graphs, together with symbolic calculations and manipulations. Pure mathematics in university shifts…

  11. Weak rigidity in the PPN formalism

    SciTech Connect

    del Olmo, V.; Olivert, J.

    1987-04-01

    The influence of the concept of weakly rigid almost-thermodynamic material schemes on the classical deformations is analyzed. The methods of the PPN approximation are considered. In this formalism, the equations that characterize the weak rigidity are expressed. As a consequence of that, an increase of two orders of magnitude in the strain rate tensor is obtained.

  12. Formalization and Analysis of Reasoning by Assumption

    ERIC Educational Resources Information Center

    Bosse, Tibor; Jonker, Catholijn M.; Treur, Jan

    2006-01-01

    This article introduces a novel approach for the analysis of the dynamics of reasoning processes and explores its applicability for the reasoning pattern called reasoning by assumption. More specifically, for a case study in the domain of a Master Mind game, it is shown how empirical human reasoning traces can be formalized and automatically…

  13. Helping Students Understand Formal Chemical Concepts.

    ERIC Educational Resources Information Center

    Ward, Charles R.; Herron, J. Dudley

    1980-01-01

    Investigated outcomes of the use of the learning cycle, which divides instruction into the Piagetian phases of exploration, invention, and discovery in general college chemistry laboratory experiments. Differences between concrete and formal operational students were explored in students' ability to master chemistry material varying in cognitive…

  14. Formal and Applied Counseling in Israel

    ERIC Educational Resources Information Center

    Israelashvili, Moshe; Wegman-Rozi, Orit

    2012-01-01

    Living in Israel is intensive and demanding but also meaningful and exciting. This article addresses the gap between the narrowly defined formal status of counseling in Israel and the widespread occurrence of counseling in various settings. It is argued that several recent changes, especially in the definition of treatment, along with the…

  15. A Simplified Approach to Product Operator Formalism

    ERIC Educational Resources Information Center

    Spiese, Christopher E.

    2004-01-01

    The utilization of the simple and traditional vector model-based product operator formalism is highlighted. It is seen as a critical device in the area of nuclear magnetic resonance (NMR) spectrometry for a comprehensive analysis of spin coupling and quantum coherences.

  16. Quantum formalism to describe binocular rivalry.

    PubMed

    Manousakis, Efstratios

    2009-11-01

    On the basis of the general character and operation of the process of perception, a formalism is sought to mathematically describe the subjective or abstract/mental process of perception. It is shown that the formalism of orthodox quantum theory of measurement, where the observer plays a key role, is a broader mathematical foundation which can be adopted to describe the dynamics of the subjective experience. The mathematical formalism describes the psychophysical dynamics of the subjective or cognitive experience as communicated to us by the subject. Subsequently, the formalism is used to describe simple perception processes and, in particular, to describe the probability distribution of dominance duration obtained from the testimony of subjects experiencing binocular rivalry. Using this theory and parameters based on known values of neuronal oscillation frequencies and firing rates, the calculated probability distribution of dominance duration of rival states in binocular rivalry under various conditions is found to be in good agreement with available experimental data. This theory naturally explains an observed marked increase in dominance duration in binocular rivalry upon periodic interruption of stimulus and yields testable predictions for the distribution of perceptual alteration in time. PMID:19520143

  17. 39 CFR 3001.20 - Formal intervention.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 39 Postal Service 1 2012-07-01 2012-07-01 false Formal intervention. 3001.20 Section 3001.20... position of the intervenor with regard to the proposed changes in postal rates, fees, classifications, or... responses to discovery requests filed by that intervenor. (e) Effect of intervention. A person filing...

  18. 39 CFR 3001.20 - Formal intervention.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 39 Postal Service 1 2014-07-01 2014-07-01 false Formal intervention. 3001.20 Section 3001.20... proposed changes in postal rates, fees, classifications, or services, or the subject matter of the... intervention shall delay on a day-for-day basis, the date for responses to discovery requests filed by...

  19. 39 CFR 3001.20 - Formal intervention.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 39 Postal Service 1 2011-07-01 2011-07-01 false Formal intervention. 3001.20 Section 3001.20... position of the intervenor with regard to the proposed changes in postal rates, fees, classifications, or... responses to discovery requests filed by that intervenor. (e) Effect of intervention. A person filing...

  20. 39 CFR 3001.20 - Formal intervention.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 39 Postal Service 1 2013-07-01 2013-07-01 false Formal intervention. 3001.20 Section 3001.20... position of the intervenor with regard to the proposed changes in postal rates, fees, classifications, or... responses to discovery requests filed by that intervenor. (e) Effect of intervention. A person filing...

  1. Connecting Formal and Informal Learning Experiences

    ERIC Educational Resources Information Center

    O'Mahony, Timothy Kieran

    2010-01-01

    The learning study reports on part of a larger project being lead by the author. In this dissertation I explore one goal of this project--to understand effects on student learning outcomes as a function of using different methods for connecting out-of-school experiential learning with formal school-based instruction. There is a long history of…

  2. Formal Schema Theory and Teaching EFL Reading

    ERIC Educational Resources Information Center

    Young, Barbara N; Man, Zhou

    2005-01-01

    Inquirers designed and conducted a study investigating whether or not results derived from previous research focusing on teaching and learning English as a native or foreign language would be replicated in a learning environment in which English is taught as a foreign language as in China. Because activation of formal schemata plays an important…

  3. Formal Thought at the High School Level

    ERIC Educational Resources Information Center

    Johnson, Donald

    1977-01-01

    A study was undertaken to determine the Piagetian stages of intellectual development of a group of Saskatchewan high school students. Results confirmed that the percentage of students at the final substage of formal thought was less than 50 percent, indicating serious problems. (JC)

  4. 50 CFR 402.14 - Formal consultation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... OF COMMERCE); ENDANGERED SPECIES COMMITTEE REGULATIONS SUBCHAPTER A INTERAGENCY COOPERATION-ENDANGERED SPECIES ACT OF 1973, AS AMENDED Consultation Procedures § 402.14 Formal consultation. (a... time to determine whether any action may affect listed species or critical habitat. If such...

  5. 50 CFR 402.14 - Formal consultation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., DEPARTMENT OF COMMERCE); ENDANGERED SPECIES COMMITTEE REGULATIONS SUBCHAPTER A INTERAGENCY COOPERATION-ENDANGERED SPECIES ACT OF 1973, AS AMENDED Consultation Procedures § 402.14 Formal consultation. (a... time to determine whether any action may affect listed species or critical habitat. If such...

  6. 50 CFR 402.14 - Formal consultation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., DEPARTMENT OF COMMERCE); ENDANGERED SPECIES COMMITTEE REGULATIONS SUBCHAPTER A INTERAGENCY COOPERATION-ENDANGERED SPECIES ACT OF 1973, AS AMENDED Consultation Procedures § 402.14 Formal consultation. (a... time to determine whether any action may affect listed species or critical habitat. If such...

  7. 50 CFR 402.14 - Formal consultation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., DEPARTMENT OF COMMERCE); ENDANGERED SPECIES COMMITTEE REGULATIONS SUBCHAPTER A INTERAGENCY COOPERATION-ENDANGERED SPECIES ACT OF 1973, AS AMENDED Consultation Procedures § 402.14 Formal consultation. (a... time to determine whether any action may affect listed species or critical habitat. If such...

  8. 50 CFR 402.14 - Formal consultation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... OF COMMERCE); ENDANGERED SPECIES COMMITTEE REGULATIONS SUBCHAPTER A INTERAGENCY COOPERATION-ENDANGERED SPECIES ACT OF 1973, AS AMENDED Consultation Procedures § 402.14 Formal consultation. (a... time to determine whether any action may affect listed species or critical habitat. If such...

  9. 28 CFR 68.39 - Formal hearings.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Formal hearings. 68.39 Section 68.39 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) RULES OF PRACTICE AND PROCEDURE FOR ADMINISTRATIVE HEARINGS BEFORE ADMINISTRATIVE LAW JUDGES IN CASES INVOLVING ALLEGATIONS OF UNLAWFUL EMPLOYMENT...

  10. Convergent formal synthesis of (±)-roseophilin.

    PubMed

    Song, Chuanjun; Liu, Hui; Hong, Meiling; Liu, Yuanyuan; Jia, Feifei; Sun, Li; Pan, Zhenliang; Chang, Junbiao

    2012-01-01

    A facile convergent synthesis of the tricyclic core 2 of roseophilin is described, which represents the shortest route so far for the formal synthesis of roseophilin. The key step was a tandem pyrrole acylation-Nazarov cyclization reaction to form the cyclopenta[b]pyrrole moiety 4. PMID:22098172

  11. Informal Science Learning in the Formal Classroom

    ERIC Educational Resources Information Center

    Walsh, Lori; Straits, William

    2014-01-01

    In this article the authors share advice from the viewpoints of both a formal and informal educator that will help teachers identify the right Informal Science Institutions (ISIs)--institutions that specialize in learning that occurs outside of the school setting--to maximize their students' learning and use informal education to their…

  12. Teaching Some Informatics Concepts Using Formal System

    ERIC Educational Resources Information Center

    Yang, Sojung; Park, Seongbin

    2014-01-01

    There are many important issues in informatics and many agree that algorithms and programming are most important issues that need to be included in informatics education (Dagiene and Jevsikova, 2012). In this paper, we propose how some of these issues can be easily taught using the notion of a formal system which consists of axioms and inference…

  13. An Elementary Formalism for General Relativity.

    ERIC Educational Resources Information Center

    diSessa, Andrea A.

    1981-01-01

    An elementary formalism is developed for representing curved space-time which allows transparent qualitative explanation of general relativistic effects and is used to make a conceptual analysis of Einstein's principle of equivalence. A final section outlines a number of student activities. (Author/SK)

  14. Safety in Children's Formal Play Environments.

    ERIC Educational Resources Information Center

    Wilkinson, Paul F.; Lockhart, Robert

    This study was designed to examine the issue of the safety of children's formal play environments. Safety was defined in terms of morbidity and mortality data. Protection and safety education were considered the prime factors in accident prevention while the goal of a safety program was considered to be the minimizing of injuries. Several data…

  15. HIV Education in the Formal Curriculum

    ERIC Educational Resources Information Center

    Nsubuga, Yusuf K.; Bonnet, Sandrine

    2009-01-01

    The AIDS epidemic presents a complex of issues that require global answers, involving entire societies. The only sustainable solution is to include all sectors of society in a multidisciplinary collaboration, within which the formal education system plays a key role in delivering a comprehensive response to the disease at the national level.…

  16. Formalism and the notion of truth

    NASA Astrophysics Data System (ADS)

    Spencer, Joseph M.

    The most widely acknowledged conceptions of truth take some kind of relation to be at truth's core. This dissertation attempts to establish that an adequate conception of this relation begins with an investigation of the entanglement of the formal and the material as set forth in the model theoretical development of set theoretical mathematics. Truth concerns first and most crucially a certain commerce across the border between the formal and the material, between the ideal and the real. The entanglement of the formal and the material must be thought in itself, apart from or prior to any assimilation into philosophical schemas committed to larger metaphysical claims. This is accomplished in model theory. The twentieth century witnessed two attempts at bringing model theoretical mathematics to bear on accounting philosophically for the concept of truth: that of Alfred Tarski, and that of Alain Badiou. In order to investigate the relevance of model theory to the task of working out a philosophical conception of truth, this dissertation investigates, through comparative work, these two thinkers. It is necessary to see where their projects converge in important ways, as well as where their projects diverge in equally important ways. What brings their work into close proximity is their shared conviction that truth must be thought in light of model theory. Nonetheless, the two do not agree about exactly how model theory sheds light on truth. Comparative study thus reveals both a shared site for thinking and a struggle over the significance of that site. Agreement between Tarski and Badiou concerns the excess of the purely formal over itself, marked by the generation of an undecidable statement within formal systems of a certain level of complexity. Both thinkers determine that this formal excess touches on the material, and both further determine that the consequent entanglement of the formal and the material provides the basic frame for any philosophical consideration

  17. 20 CFR 702.333 - Formal hearings; parties.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Formal hearings; parties. 702.333 Section 702... Procedures Formal Hearings § 702.333 Formal hearings; parties. (a) The necessary parties for a formal hearing... pursuant to these regulations on behalf of the Director as an interested party....

  18. 20 CFR 702.347 - Formal hearings; termination.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Formal hearings; termination. 702.347 Section 702.347 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR LONGSHOREMEN... Adjudication Procedures Formal Hearings § 702.347 Formal hearings; termination. (a) Formal hearings...

  19. 20 CFR 702.347 - Formal hearings; termination.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 4 2013-04-01 2013-04-01 false Formal hearings; termination. 702.347 Section 702.347 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR LONGSHOREMEN... Adjudication Procedures Formal Hearings § 702.347 Formal hearings; termination. (a) Formal hearings...

  20. 20 CFR 702.347 - Formal hearings; termination.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 4 2014-04-01 2014-04-01 false Formal hearings; termination. 702.347 Section 702.347 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR LONGSHOREMEN... Adjudication Procedures Formal Hearings § 702.347 Formal hearings; termination. (a) Formal hearings...

  1. 20 CFR 702.347 - Formal hearings; termination.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 4 2012-04-01 2012-04-01 false Formal hearings; termination. 702.347 Section 702.347 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR LONGSHOREMEN... Adjudication Procedures Formal Hearings § 702.347 Formal hearings; termination. (a) Formal hearings...

  2. 20 CFR 702.347 - Formal hearings; termination.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Formal hearings; termination. 702.347 Section 702.347 Employees' Benefits EMPLOYMENT STANDARDS ADMINISTRATION, DEPARTMENT OF LABOR LONGSHOREMEN'S... Procedures Formal Hearings § 702.347 Formal hearings; termination. (a) Formal hearings are...

  3. 20 CFR 702.336 - Formal hearings; new issues.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Formal hearings; new issues. 702.336 Section... Procedures Formal Hearings § 702.336 Formal hearings; new issues. (a) If, during the course of the formal hearing, the evidence presented warrants consideration of an issue or issues not previously...

  4. Writing job descriptions.

    PubMed

    Schaffner, M

    1990-01-01

    The skill of writing job descriptions begins with an understanding of the advantages, as well as the basic elements, of a well written description. The end result should be approved and updated as needed. Having a better understanding of this process makes writing the job description a challenge rather than a chore.

  5. Formal Safety Certification of Aerospace Software

    NASA Technical Reports Server (NTRS)

    Denney, Ewen; Fischer, Bernd

    2005-01-01

    In principle, formal methods offer many advantages for aerospace software development: they can help to achieve ultra-high reliability, and they can be used to provide evidence of the reliability claims which can then be subjected to external scrutiny. However, despite years of research and many advances in the underlying formalisms of specification, semantics, and logic, formal methods are not much used in practice. In our opinion this is related to three major shortcomings. First, the application of formal methods is still expensive because they are labor- and knowledge-intensive. Second, they are difficult to scale up to complex systems because they are based on deep mathematical insights about the behavior of the systems (t.e., they rely on the "heroic proof"). Third, the proofs can be difficult to interpret, and typically stand in isolation from the original code. In this paper, we describe a tool for formally demonstrating safety-relevant aspects of aerospace software, which largely circumvents these problems. We focus on safely properties because it has been observed that safety violations such as out-of-bounds memory accesses or use of uninitialized variables constitute the majority of the errors found in the aerospace domain. In our approach, safety means that the program will not violate a set of rules that can range for the simple memory access rules to high-level flight rules. These different safety properties are formalized as different safety policies in Hoare logic, which are then used by a verification condition generator along with the code and logical annotations in order to derive formal safety conditions; these are then proven using an automated theorem prover. Our certification system is currently integrated into a model-based code generation toolset that generates the annotations together with the code. However, this automated formal certification technology is not exclusively constrained to our code generator and could, in principle, also be

  6. Non-Formal Education: The Definitional Problem. Program of Studies in Non-Formal Education Discussion Papers Number 2.

    ERIC Educational Resources Information Center

    Kleis, Russell J.; And Others

    The three essays in this discussion paper present ways of structuring the concept of non-formal education. "Toward a Contextual Definition of Non-Formal Education" isolates three primary sub-systems: organizational, human, and curricular. Within these subsets non-formal education is differentiated from formal education by a more loosely integrated…

  7. General formalism for the efficient calculation of the Hessian matrix of EM data misfit and Hessian-vector products based upon adjoint sources approach

    NASA Astrophysics Data System (ADS)

    Pankratov, Oleg; Kuvshinov, Alexey

    2015-03-01

    3-D electromagnetic (EM) studies of the Earth have advanced significantly over the past decade. Despite a certain success of the 3-D EM inversions of real data sets, the quantitative assessment of the recovered models is still a challenging problem. It is known that one can gain valuable information about model uncertainties from the analysis of Hessian matrix. However, even with modern computational capabilities the calculation of the Hessian matrix based on numerical differentiation is extremely time consuming. Much more efficient way to compute the Hessian matrix is provided by an `adjoint sources' methodology. The computation of Hessian matrix (and Hessian-vector products) using adjoint formulation is now well-established approach, especially in seismic inverse modelling. As for EM inverse modelling we did not find in the literature a description of the approach, which would allow EM researchers to apply this methodology in a straightforward manner to their scenario of interest. In the paper, we present formalism for the efficient calculation of the Hessian matrix using adjoint sources approach. We also show how this technique can be implemented to calculate multiple Hessian-vector products very efficiently. The formalism is general in the sense that it allows to work with responses that arise in EM problem set-ups either with natural- or controlled-source excitations. The formalism allows for various types of parametrization of the 3-D conductivity distribution. Using this methodology one can readily obtain appropriate formulae for the specific sounding methods. To illustrate the concept we provide such formulae for two EM techniques: magnetotellurics and controlled-source sounding with vertical magnetic dipole as a source.

  8. Systolic temporal arithmetic: A new formalism for specification, verification, and synthesis of systolic arrays

    SciTech Connect

    Ling, N.

    1989-01-01

    A novel formalism, termed Systolic Temporal Arithmetic (STA), is introduced. It provides necessary constructs to describe arithmetic operations in dynamic environments. The motivation behind the development of STA is to use it for systolic array design at the array architecture level. It is particularly useful for formally specifying systolic array designs, and for formally verifying their correctness with respect to the algorithm specifications. Besides providing value and operation abstractions from the lower level, the formalism exploits unique systolic features such as synchrony, regularity, repeatability, modularity, pipelinability, parallel processing ability, as well as spatial and temporal locality, to provide constructs and verification techniques for simple, efficient, and effective systolic array specification verification. STA overcomes many limitations of current specification and verification techniques. It can be used with lower level formalism for multilevel reasoning of systolic arrays. Application examples are given to show how STA can be applied to specify and verify several different systolic arrays. To present a more unified design environment, STA is also extended to describe systolic array synthesis process. A synthesis procedure for systolic arrays is presented which also includes an algorithm transformation technique developed that can improve the computation time of resulting arrays for suitable algorithms, without much increase in area requirement. Several systolic array synthesis examples are also provided in this dissertation.

  9. A Study of Relationships Between Formal Organizational Structure and Organizational Climate in Selected Urban and Suburban Schools.

    ERIC Educational Resources Information Center

    Ames, John L.; And Others

    In this study, assessment of the formal organizational structure was limited to a determination of authority and responsibility in personnel, supervision, curriculum, policymaking, and community relations. The study data were gathered from the results of the (1) Organizational Climate Description Questionnaire, (2) Professional Self-Enchancement…

  10. Can Schools Be Autonomous in a Centralised Educational System?: On Formal and Actual School Autonomy in the Italian Context

    ERIC Educational Resources Information Center

    Agasisti, Tommaso; Catalano, Giuseppe; Sibiano, Piergiacomo

    2013-01-01

    Purpose: The purpose of this paper is to examine the difference between formal and real school autonomy in the Italian educational system. The Italian case is characterised by low levels of school autonomy. It is interesting to consider whether heterogeneity of patterns is possible in this context. A description of this heterogeneity is provided…

  11. Formal verification of human-automation interaction

    NASA Technical Reports Server (NTRS)

    Degani, Asaf; Heymann, Michael

    2002-01-01

    This paper discusses a formal and rigorous approach to the analysis of operator interaction with machines. It addresses the acute problem of detecting design errors in human-machine interaction and focuses on verifying the correctness of the interaction in complex and automated control systems. The paper describes a systematic methodology for evaluating whether the interface provides the necessary information about the machine to enable the operator to perform a specified task successfully and unambiguously. It also addresses the adequacy of information provided to the user via training material (e.g., user manual) about the machine's behavior. The essentials of the methodology, which can be automated and applied to the verification of large systems, are illustrated by several examples and through a case study of pilot interaction with an autopilot aboard a modern commercial aircraft. The expected application of this methodology is an augmentation and enhancement, by formal verification, of human-automation interfaces.

  12. Hamiltonian formalism of minimal massive gravity

    NASA Astrophysics Data System (ADS)

    Mahdavian Yekta, Davood

    2015-09-01

    In this paper, we study the three-dimensional minimal massive gravity (MMG) in the Hamiltonian formalism. At first, we define the canonical gauge generators as building blocks in this formalism and then derive the canonical expressions for the asymptotic conserved charges. The construction of a consistent asymptotic structure of MMG requires introducing suitable boundary conditions. In the second step, we show that the Poisson bracket algebra of the improved canonical gauge generators produces an asymptotic gauge group, which includes two separable versions of the Virasoro algebras. For instance, we study the Banados-Teitelboim-Zanelli (BTZ) black hole as a solution of the MMG field equations, and the conserved charges give the energy and angular momentum of the BTZ black hole. Finally, we compute the black hole entropy from the Cardy formula in the dual conformal field theory and show our result is consistent with the value obtained by using the Smarr formula from the holographic principle.

  13. A Formal Framework for Workflow Analysis

    NASA Astrophysics Data System (ADS)

    Cravo, Glória

    2010-09-01

    In this paper we provide a new formal framework to model and analyse workflows. A workflow is the formal definition of a business process that consists in the execution of tasks in order to achieve a certain objective. In our work we describe a workflow as a graph whose vertices represent tasks and the arcs are associated to workflow transitions. Each task has associated an input/output logic operator. This logic operator can be the logical AND (•), the OR (⊗), or the XOR -exclusive-or—(⊕). Moreover, we introduce algebraic concepts in order to completely describe completely the structure of workflows. We also introduce the concept of logical termination. Finally, we provide a necessary and sufficient condition for this property to hold.

  14. Formal Problem Domain Modeling within MDA

    NASA Astrophysics Data System (ADS)

    Osis, Janis; Asnina, Erika; Grave, Andrejs

    The proposed approach called Topological Functioning Modeling for Model Driven Architecture (TFM4MDA) uses formal mathematical foundations of Topological Functioning Model (TFM). It introduces the main feature of MDA - Separation of Concerns by formal analysis of a business system, enables mapping to functional requirements and verifying whether those requirements are in conformity with the TFM of the problem domain. By using a goal-based method, a holistic behavior of the planned application can be decomposed in accordance with the goals. Graph transformation from the TFM to a conceptual model (or a domain object model) enables establishing the definition of domain concepts and their relations. The paper also suggests a concept of a tool for TFM4MDA, which is realized as an Eclipse plug-in.

  15. Hartle formalism for rotating Newtonian configurations

    NASA Astrophysics Data System (ADS)

    Boshkayev, Kuantay; Quevedo, Hernando; Kalymova, Zhanerke; Zhami, Bakytzhan

    2016-11-01

    We apply the Hartle formalism to study equilibrium configurations in the framework of Newtonian gravity. This approach allows one to study in a simple manner the properties of the interior gravitational field in the case of static as well as stationary rotating stars in hydrostatic equilibrium. It is shown that the gravitational equilibrium conditions reduce to a system of ordinary differential equations which can be integrated numerically. We derive all the relevant equations up to the second order in the angular velocity. Moreover, we find explicitly the total mass, the moment of inertia, the quadrupole moment, the polar and equatorial radii, the eccentricity and the gravitational binding energy of the rotating body. We also present the procedure to calculate the gravitational Love number. We test the formalism in the case of white dwarfs and show its compatibility with the known results in the literature.

  16. Generalizing Prototype Theory: A Formal Quantum Framework

    PubMed Central

    Aerts, Diederik; Broekaert, Jan; Gabora, Liane; Sozzo, Sandro

    2016-01-01

    Theories of natural language and concepts have been unable to model the flexibility, creativity, context-dependence, and emergence, exhibited by words, concepts and their combinations. The mathematical formalism of quantum theory has instead been successful in capturing these phenomena such as graded membership, situational meaning, composition of categories, and also more complex decision making situations, which cannot be modeled in traditional probabilistic approaches. We show how a formal quantum approach to concepts and their combinations can provide a powerful extension of prototype theory. We explain how prototypes can interfere in conceptual combinations as a consequence of their contextual interactions, and provide an illustration of this using an intuitive wave-like diagram. This quantum-conceptual approach gives new life to original prototype theory, without however making it a privileged concept theory, as we explain at the end of our paper. PMID:27065436

  17. Generalizing Prototype Theory: A Formal Quantum Framework.

    PubMed

    Aerts, Diederik; Broekaert, Jan; Gabora, Liane; Sozzo, Sandro

    2016-01-01

    Theories of natural language and concepts have been unable to model the flexibility, creativity, context-dependence, and emergence, exhibited by words, concepts and their combinations. The mathematical formalism of quantum theory has instead been successful in capturing these phenomena such as graded membership, situational meaning, composition of categories, and also more complex decision making situations, which cannot be modeled in traditional probabilistic approaches. We show how a formal quantum approach to concepts and their combinations can provide a powerful extension of prototype theory. We explain how prototypes can interfere in conceptual combinations as a consequence of their contextual interactions, and provide an illustration of this using an intuitive wave-like diagram. This quantum-conceptual approach gives new life to original prototype theory, without however making it a privileged concept theory, as we explain at the end of our paper.

  18. Generalizing Prototype Theory: A Formal Quantum Framework.

    PubMed

    Aerts, Diederik; Broekaert, Jan; Gabora, Liane; Sozzo, Sandro

    2016-01-01

    Theories of natural language and concepts have been unable to model the flexibility, creativity, context-dependence, and emergence, exhibited by words, concepts and their combinations. The mathematical formalism of quantum theory has instead been successful in capturing these phenomena such as graded membership, situational meaning, composition of categories, and also more complex decision making situations, which cannot be modeled in traditional probabilistic approaches. We show how a formal quantum approach to concepts and their combinations can provide a powerful extension of prototype theory. We explain how prototypes can interfere in conceptual combinations as a consequence of their contextual interactions, and provide an illustration of this using an intuitive wave-like diagram. This quantum-conceptual approach gives new life to original prototype theory, without however making it a privileged concept theory, as we explain at the end of our paper. PMID:27065436

  19. Formal Definition and Construction of Nominative Signature

    NASA Astrophysics Data System (ADS)

    Liu, Dennis Y. W.; Wong, Duncan S.; Huang, Xinyi; Wang, Guilin; Huang, Qiong; Mu, Yi; Susilo, Willy

    Since the introduction of nominative signature in 1996, there are three problems that have still not been solved. First, there is no convincing application proposed; second, there is no formal security model available; and third, there is no proven secure scheme constructed, given that all the previous schemes have already been found flawed. In this paper, we give positive answers to these problems. First, we illustrate that nominative signature is a better tool for building user certification systems which were originally implemented using universal designated-verifier signature. Second, we propose a formal definition and adversarial model for nominative signature. Third, we show that Chaum's undeniable signature can be transformed to an efficient nominative signature by simply using a standard signature. The security of our transformation can be proven under the standard number-theoretic assumption.

  20. Measurements and mathematical formalism of quantum mechanics

    NASA Astrophysics Data System (ADS)

    Slavnov, D. A.

    2007-03-01

    A scheme for constructing quantum mechanics is given that does not have Hilbert space and linear operators as its basic elements. Instead, a version of algebraic approach is considered. Elements of a noncommutative algebra (observables) and functionals on this algebra (elementary states) associated with results of single measurements are used as primary components of the scheme. On the one hand, it is possible to use within the scheme the formalism of the standard (Kolmogorov) probability theory, and, on the other hand, it is possible to reproduce the mathematical formalism of standard quantum mechanics, and to study the limits of its applicability. A short outline is given of the necessary material from the theory of algebras and probability theory. It is described how the mathematical scheme of the paper agrees with the theory of quantum measurements, and avoids quantum paradoxes.

  1. Group adaptation, formal darwinism and contextual analysis.

    PubMed

    Okasha, S; Paternotte, C

    2012-06-01

    We consider the question: under what circumstances can the concept of adaptation be applied to groups, rather than individuals? Gardner and Grafen (2009, J. Evol. Biol.22: 659-671) develop a novel approach to this question, building on Grafen's 'formal Darwinism' project, which defines adaptation in terms of links between evolutionary dynamics and optimization. They conclude that only clonal groups, and to a lesser extent groups in which reproductive competition is repressed, can be considered as adaptive units. We re-examine the conditions under which the selection-optimization links hold at the group level. We focus on an important distinction between two ways of understanding the links, which have different implications regarding group adaptationism. We show how the formal Darwinism approach can be reconciled with G.C. Williams' famous analysis of group adaptation, and we consider the relationships between group adaptation, the Price equation approach to multi-level selection, and the alternative approach based on contextual analysis.

  2. Stochastic Formal Correctness of Numerical Algorithms

    NASA Technical Reports Server (NTRS)

    Daumas, Marc; Lester, David; Martin-Dorel, Erik; Truffert, Annick

    2009-01-01

    We provide a framework to bound the probability that accumulated errors were never above a given threshold on numerical algorithms. Such algorithms are used for example in aircraft and nuclear power plants. This report contains simple formulas based on Levy's and Markov's inequalities and it presents a formal theory of random variables with a special focus on producing concrete results. We selected four very common applications that fit in our framework and cover the common practices of systems that evolve for a long time. We compute the number of bits that remain continuously significant in the first two applications with a probability of failure around one out of a billion, where worst case analysis considers that no significant bit remains. We are using PVS as such formal tools force explicit statement of all hypotheses and prevent incorrect uses of theorems.

  3. A Tentative Description of Post-Formal Thinking: The Critical Confrontation with Cognitive Theory.

    ERIC Educational Resources Information Center

    Kincheloe, Joe L.; Steinberg, Shirley R.

    1993-01-01

    Postformal thinking concerns questions of meaning and purpose, multiple perspectives, human dignity, freedom, and social responsibility. Curriculum and instruction based on postformalism involves detecting problems, uncovering hidden assumptions, seeing relationships, deconstructing, connecting logic and emotion, and attending to context. (SK)

  4. The 2(2S + 1)-formalism and its connection with other descriptions

    NASA Astrophysics Data System (ADS)

    Dvoeglazov, Valeriy V.

    2016-02-01

    In the framework of the Joos-Weinberg 2(2S + 1)-theory for massless particles, the dynamical invariants have been derived from the Lagrangian density which is considered to be a 4-vector. A la Majorana interpretation of the 6-component “spinors”, the field operators of S = 1 particles, as the left- and right-circularly polarized radiation, leads us to the conserved quantities which are analogous to those obtained by Lipkin and Sudbery. The scalar Lagrangian of the Joos-Weinberg theory is shown to be equivalent to the Lagrangian of a free massless field, introduced by Hayashi. As a consequence of a new “gauge” invariance this skew-symmetric field describes physical particles with the longitudinal components only. The interaction of the spinor field with the Weinberg’s 2(2S + 1)-component massless field is considered. New interpretation of the Weinberg field function is proposed.

  5. Flexible receiver adapter formal design review

    SciTech Connect

    Krieg, S.A.

    1995-06-13

    This memo summarizes the results of the Formal (90%) Design Review process and meetings held to evaluate the design of the Flexible Receiver Adapters, support platforms, and associated equipment. The equipment is part of the Flexible Receiver System used to remove, transport, and store long length contaminated equipment and components from both the double and single-shell underground storage tanks at the 200 area tank farms.

  6. Terra in K-16 formal education settings

    NASA Astrophysics Data System (ADS)

    Chambers, L. H.; Fischer, J. D.; Lewis, P. M.; Moore, S. W.; Oots, P. C.; Rogerson, T. M.; Hitke, K. M.; Riebeek, H.

    2009-12-01

    Since it began, the Terra mission has had an active presence in formal education at the K-16 level. This educational presence was provided through the S’COOL project for the first five years of the mission, joined by the MY NASA DATA project for the second five years. The Students’ Cloud Observations On-Line (S’COOL) Project, begun in 1997 under the auspices of the Clouds and the Earth’s Radiant Energy System (CERES) project, seeks to motivate students across the entire K-12 spectrum to learn science basics and how they tie in to a larger picture. Beginning early on, college level participants have also participated in the project, both in science classes and in science education coursework. The project uses the connection to an on-going NASA science investigation as a powerful motivator for student observations, analysis and learning, and has reached around the globe as shown in the world map. This poster will review the impact that Terra, through S’COOL, has made in formal education over the last decade. The MY NASA DATA Project began in 2004 under the NASA Research, Education and Applications Solutions Network (REASoN). A 5-year REASoN grant enabled the creation of an extensive website which wraps easily accessible Earth science data - including Terra parameters from CERES (involving MODIS data fusion), MISR, and MOPITT (an example for carbon monoxide is given in the graph, with dark areas indicating high CO levels) - with explanatory material written at the middle school level, and an extensive collection of peer-reviewed lesson plans. The MY NASA DATA site has a rapidly growing user-base and was recently adopted by a number of NASA Earth Science missions, in addition to Terra, as a formal education arm of their Education and Public Outreach efforts. This poster will summarize the contributions that Terra, through MY NASA DATA, has made to formal education since 2004.

  7. Fourth NASA Langley Formal Methods Workshop

    NASA Technical Reports Server (NTRS)

    Holloway, C. Michael (Compiler); Hayhurst, Kelly J. (Compiler)

    1997-01-01

    This publication consists of papers presented at NASA Langley Research Center's fourth workshop on the application of formal methods to the design and verification of life-critical systems. Topic considered include: Proving properties of accident; modeling and validating SAFER in VDM-SL; requirement analysis of real-time control systems using PVS; a tabular language for system design; automated deductive verification of parallel systems. Also included is a fundamental hardware design in PVS.

  8. Formalized Epistemology in a Philosophical Perspective

    NASA Astrophysics Data System (ADS)

    Barreau, Hervé

    The need for a formalized epistemology is recognized by all scholars who think that the relativity of all sciences must not be referred to a social relativism. In XXth century, Husserl was the protagonist of such an epistemic philosophy. But this philosophy was more successful in social and human sciences than in natural sciences. In this latter domain, quantum mechanics obeys the requirements of a Kantien perspective in a more precise sense that was the case with Newtonian mechanics.

  9. [How to write an article: formal aspects].

    PubMed

    Corral de la Calle, M A; Encinas de la Iglesia, J

    2013-06-01

    Scientific research and the publication of the results of the studies go hand in hand. Exquisite research methods can only be adequately reflected in formal publication with the optimum structure. To ensure the success of this process, it is necessary to follow orderly steps, including selecting the journal in which to publish and following the instructions to authors strictly as well as the guidelines elaborated by diverse societies of editors and other institutions. It is also necessary to structure the contents of the article in a logical and attractive way and to use an accurate, clear, and concise style of language. Although not all the authors are directly involved in the actual writing, elaborating a scientific article is a collective undertaking that does not finish until the article is published. This article provides practical advice about formal and not-so-formal details to take into account when writing a scientific article as well as references that will help readers find more information in greater detail.

  10. Formalizing Darwinism and inclusive fitness theory

    PubMed Central

    Grafen, Alan

    2009-01-01

    Inclusive fitness maximization is a basic building block for biological contributions to any theory of the evolution of society. There is a view in mathematical population genetics that nothing is caused to be maximized in the process of natural selection, but this is explained as arising from a misunderstanding about the meaning of fitness maximization. Current theoretical work on inclusive fitness is discussed, with emphasis on the author's ‘formal Darwinism project’. Generally, favourable conclusions are drawn about the validity of assuming fitness maximization, but the need for continuing work is emphasized, along with the possibility that substantive exceptions may be uncovered. The formal Darwinism project aims more ambitiously to represent in a formal mathematical framework the central point of Darwin's Origin of Species, that the mechanical processes of inheritance and reproduction can give rise to the appearance of design, and it is a fitting ambition in Darwin's bicentenary year to capture his most profound discovery in the lingua franca of science. PMID:19805422

  11. Experience report: Using formal methods for requirements analysis of critical spacecraft software

    NASA Technical Reports Server (NTRS)

    Lutz, Robyn R.; Ampo, Yoko

    1994-01-01

    Formal specification and analysis of requirements continues to gain support as a method for producing more reliable software. However, the introduction of formal methods to a large software project is difficult, due in part to the unfamiliarity of the specification languages and the lack of graphics. This paper reports results of an investigation into the effectiveness of formal methods as an aid to the requirements analysis of critical, system-level fault-protection software on a spacecraft currently under development. Our experience indicates that formal specification and analysis can enhance the accuracy of the requirements and add assurance prior to design development in this domain. The work described here is part of a larger, NASA-funded research project whose purpose is to use formal-methods techniques to improve the quality of software in space applications. The demonstration project described here is part of the effort to evaluate experimentally the effectiveness of supplementing traditional engineering approaches to requirements specification with the more rigorous specification and analysis available with formal methods.

  12. Informal and formal mental health: preliminary qualitative findings

    PubMed Central

    O'Neill, Linda; George, Serena; Koehn, Corinne; Shepard, Blythe

    2013-01-01

    Background Northern-based research on mental health support, no matter the specific profession, helps to inform instruction of new practitioners and practitioners already working in rural or isolated conditions. Understanding the complexities of northern mental health support not only benefits clients and practitioners living in the North, but also helps prepare psychologists and counsellors preparing to work in other countries with large rural and isolated populations. The qualitative phase is part of a multi-year research study on informal and formal mental health support in northern Canada involving the use of qualitative and quantitative data collection and analysis methods. Objective The main objective of the qualitative phase interviews was to document in-depth the situation of formal and informal helpers in providing mental health support in isolated northern communities in northern British Columbia, northern Alberta, Yukon and Northwest Territories (NWT). The intent of in-depth interviews was to collect descriptive information on the unique working conditions of northern helping practitioners for the development of a survey and subsequent community action plans for helping practitioner support. Design Twenty participants in northern BC, Yukon and NWT participated in narrative interviews. Consensual qualitative research (CQR) was used in the analysis completed by 7 researchers. The principal researcher and research associate then worked through all 7 analyses, defining common categories and themes, and using selections from each researcher in order to ensure that everyone's analysis was represented in the final consensual summary. Results The preliminary results include 7 main categories consisting of various themes. Defining elements of northern practice included the need for generalist knowledge and cultural sensitivity. The task of working with and negotiating membership in community was identified as essential for northern mental health support. The need

  13. Formalized landscape models for surveying and modelling tasks

    NASA Astrophysics Data System (ADS)

    Löwner, Marc-Oliver

    2010-05-01

    scenarios of landscape modelling. Commercial GI-software is not adapted to the needs of the science of geomorphology. Therefore the development of an application model i. e. a formal description of semantics is imperative to partake in technologies like Web Feature Services supporting interoperable data transfer.

  14. A Formal Model of Partitioning for Integrated Modular Avionics

    NASA Technical Reports Server (NTRS)

    DiVito, Ben L.

    1998-01-01

    The aviation industry is gradually moving toward the use of integrated modular avionics (IMA) for civilian transport aircraft. An important concern for IMA is ensuring that applications are safely partitioned so they cannot interfere with one another. We have investigated the problem of ensuring safe partitioning and logical non-interference among separate applications running on a shared Avionics Computer Resource (ACR). This research was performed in the context of ongoing standardization efforts, in particular, the work of RTCA committee SC-182, and the recently completed ARINC 653 application executive (APEX) interface standard. We have developed a formal model of partitioning suitable for evaluating the design of an ACR. The model draws from the mathematical modeling techniques developed by the computer security community. This report presents a formulation of partitioning requirements expressed first using conventional mathematical notation, then formalized using the language of SRI'S Prototype Verification System (PVS). The approach is demonstrated on three candidate designs, each an abstraction of features found in real systems.

  15. Multimedia content description framework

    NASA Technical Reports Server (NTRS)

    Bergman, Lawrence David (Inventor); Kim, Michelle Yoonk Yung (Inventor); Li, Chung-Sheng (Inventor); Mohan, Rakesh (Inventor); Smith, John Richard (Inventor)

    2003-01-01

    A framework is provided for describing multimedia content and a system in which a plurality of multimedia storage devices employing the content description methods of the present invention can interoperate. In accordance with one form of the present invention, the content description framework is a description scheme (DS) for describing streams or aggregations of multimedia objects, which may comprise audio, images, video, text, time series, and various other modalities. This description scheme can accommodate an essentially limitless number of descriptors in terms of features, semantics or metadata, and facilitate content-based search, index, and retrieval, among other capabilities, for both streamed or aggregated multimedia objects.

  16. An Ill-Structured PBL-Based Microprocessor Course without Formal Laboratory

    ERIC Educational Resources Information Center

    Kim, Jungkuk

    2012-01-01

    This paper introduces a problem-based learning (PBL) microprocessor application course designed according to the following strategies: 1) hands-on training without having a formal laboratory, and 2) intense student-centered cooperative learning through an ill-structured problem. PBL was adopted as the core educational technique of the course to…

  17. Increasing the Perceived Value of Formal Education in Poor Black Populations.

    ERIC Educational Resources Information Center

    Grubb, Henry J.

    1987-01-01

    Because Blacks have not taken full advantage of the opportunities that have arisen in higher education, a program using such techniques as self-efficacy, modeling, and social marketing should be implemented to effect a change in the attitude of Black community toward formal education. (CB)

  18. "It's Never Too Late." A Learning Pack for Older People with Few or No Formal Qualifications.

    ERIC Educational Resources Information Center

    Oxford Univ. (England). Ruskin Coll.

    This learning pack, which was developed in Britain primarily for use with small groups of older adults who have had little formal education, contains nine self-contained units of learning activities dealing with topics related to older adults' everyday lives. The following topics are covered: techniques for organizing and running a group; myths…

  19. Formal specification is an experimental science

    SciTech Connect

    Bjorner, D.

    1992-09-01

    Traditionally, abstract models of large, complex systems have been given in free-form mathematics, combining - often in ad-hoc, not formally supported ways - notions from the disciplines of partial differential equations, functional analysis, mathematical statistics, etc. Such models have been very useful for assimilation of information, analysis (investigation), and prediction (simulation). These models have, however, usually not been helpful in deriving computer representations of the modelled systems - for the purposes of computerized monitoring and control, Computing science, concerned with how to construct objects that can exist within the computer, offers ways of complementing, and in some cases, replacing or combining traditional mathematical models. Formal, model-, as well as property-oriented, specifications in the styles of denotational (respectively, algebraic semantics) represent major approaches to such modelling. In this expository, discursive paper we illustrate what we mean by model-oriented specifications of large, complex technological computing systems. The three modelling examples covers the introvert programming methodological subject of SDEs: software development environments, the distributed computing system subject of wfs`s: (transaction) work flow systems, and the extrovert subject of robots: robotics! the thesis is, just as for mathematical modelling, that we can derive much understanding, etc., from experimentally creating such formally specified models - on paper - and that we gain little in additionally building ad-hoc prototypes. Our models are expressed in a model-oriented style using the VDM specification language Meta-IV In this paper the models only reflect the {open_quotes}data modelling{close_quotes} aspects. We observe that such data models are more easily captured in the model-oriented siyle than in the algebraic semantics property-oriented style which originally was built of the abstraction of operations. 101 refs., 4 figs.

  20. A Formal Mentorship Program for Faculty Development

    PubMed Central

    Le, Jennifer; Nazer, Lama; Hess, Karl; Wang, Jeffrey; Law, Anandi V.

    2014-01-01

    Objective. To describe the development, implementation, and evaluation of a formal mentorship program at a college of pharmacy. Methods. After extensive review of the mentorship literature within the health sciences, a formal mentorship program was developed between 2006 and 2008 to support and facilitate faculty development. The voluntary program was implemented after mentors received training, and mentors and protégés were matched and received an orientation. Evaluation consisted of conducting annual surveys and focus groups with mentors and protégés. Results. Fifty-one mentor-protégé pairs were formed from 2009 to 2012. A large majority of the mentors (82.8%-96.9%) were satisfied with the mentorship program and its procedures. The majority of the protégés (≥70%) were satisfied with the mentorship program, mentor-protégé relationship, and program logistics. Both mentors and protégés reported that the protégés most needed guidance on time management, prioritization, and work-life balance. While there were no significant improvements in the proteges’ number of grant submissions, retention rates, or success in promotion/tenure, the total number of peer-reviewed publications by junior faculty members was significantly higher after program implementation (mean of 7 per year vs 21 per year, p=0.03) in the college’s pharmacy practice and administration department. Conclusions. A formal mentorship program was successful as measured by self-reported assessments of mentors and protégés. PMID:24954940

  1. Formal Assurance Arguments: A Solution In Search of a Problem?

    NASA Technical Reports Server (NTRS)

    Graydon, Patrick J.

    2015-01-01

    An assurance case comprises evidence and argument showing how that evidence supports assurance claims (e.g., about safety or security). It is unsurprising that some computer scientists have proposed formalizing assurance arguments: most associate formality with rigor. But while engineers can sometimes prove that source code refines a formal specification, it is not clear that formalization will improve assurance arguments or that this benefit is worth its cost. For example, formalization might reduce the benefits of argumentation by limiting the audience to people who can read formal logic. In this paper, we present (1) a systematic survey of the literature surrounding formal assurance arguments, (2) an analysis of errors that formalism can help to eliminate, (3) a discussion of existing evidence, and (4) suggestions for experimental work to definitively answer the question.

  2. Formal Aspects of Human-Automation Interaction

    NASA Technical Reports Server (NTRS)

    Degani, Asaf; Heymann, Michael; Moodi, Michael; Remington, Roger (Technical Monitor)

    1998-01-01

    While new versions of automated control systems such as flight guidance systems are introduced at a rapid pace, it is widely recognized that user interaction with these machines is increasingly problematic. One cause for this difficulty that is commonly cited in the literature, is the discrepancy between the machine's behavior and the operator's (e.g., pilot) expectations. This paper discusses a formal approach to the analysis of operator's interaction with complex automated control systems. We focus attention on the issue of interface correctness; that is, on the question whether the display provides adequate information about the machine's configurations (states, modes, and associated parameters) and transitions, so as to enable the operator to successfully perform the specified set of tasks. To perform the analysis several assumptions are made: (1) A complete formal model of the machine's behavior is available (e.g., as a state transition system, or as a hybrid-machine); (2) A specification of operator's tasks is available and can be formally described (e.g., the reliable and predictable transition between activities involved in executing a climb to a new altitude); (3) The pilot is well trained and has a correct 'mental' model of the machine's response-map. By 'comparing' the machine's model with the set of operator's tasks we formally (i.e., mathematically) evaluate two questions: 1) does the machine's output interface (display) enable the operator to determine, unambiguously, what the current configuration (e.g., mode) of the machine is, and 2) does the display enable the operator to determine, unambiguously, what the next configuration of the machine will be, in response to a specified interaction by the operator (e.g., engaging a mode or changing a parameter such as a speed or target altitude). This paper describes a methodology for conducting such an evaluation using examples from automated flight control systems of modem 'glass cockpit' jetliners

  3. The conformal window from the worldline formalism

    NASA Astrophysics Data System (ADS)

    Armoni, Adi

    2010-02-01

    We use the worldline formalism to derive a universal relation for the lower boundary of the conformal window in non-supersymmetric QCD-like theories. The derivation relies on the convergence of the expansion of the fermionic determinant in terms of Wilson loops. The expansion shares a similarity with the lattice strong coupling expansion and the genus expansion in string theory. Our result relates the lower boundary of the conformal window in theories with different representations and different gauge groups. Finally, we use SQCD to estimate the boundary of the conformal window in QCD-like theories and compare it with other approaches.

  4. Formal analysis of ORM using OWL DL

    NASA Astrophysics Data System (ADS)

    Pan, Wen-lin; Liu, Da-xin

    2012-01-01

    ORM (Object Role Modeling), current version is 2.0, is a fully communication oriented information modeling method. Currently, ORM has been used in ontology engineering to model domain ontologies. To ensure the semantics of ORM model is consistent, it needs using reasoning engines to check semantic conflicts and redundancy. Furthermore, only publish ORM domain ontologies on the Semantic Web described by OWL can it is shared by different applications. Therefore, it needs to map ORM models into OWL DL. Several methods to transform ORM models have been considered and a series of general OWL DL formalization rules have been proposed.

  5. Formal analysis of ORM using OWL DL

    NASA Astrophysics Data System (ADS)

    Pan, Wen-Lin; Liu, Da-Xin

    2011-12-01

    ORM (Object Role Modeling), current version is 2.0, is a fully communication oriented information modeling method. Currently, ORM has been used in ontology engineering to model domain ontologies. To ensure the semantics of ORM model is consistent, it needs using reasoning engines to check semantic conflicts and redundancy. Furthermore, only publish ORM domain ontologies on the Semantic Web described by OWL can it is shared by different applications. Therefore, it needs to map ORM models into OWL DL. Several methods to transform ORM models have been considered and a series of general OWL DL formalization rules have been proposed.

  6. BRST and the pure spinor formalism

    SciTech Connect

    Garcia, J. Antonio

    2008-03-06

    The aim of this talk is to show the relation between the standard BRST approach of the GS superstring with the quantization technics used in the pure spinor approach to superstring. To that end we will use the Batalin-Fradkin-Tyutin (BFT) conversion program of second class constraints to first class constraints in the GS superstring using light cone coordinates. By applying this systematic procedure we were able to obtain a gauge system that is equivalent to the recent model proposed in [1] to relate the GS superstring to the pure spinor formalism.

  7. The formal verification of generic interpreters

    NASA Technical Reports Server (NTRS)

    Windley, P.; Levitt, K.; Cohen, G. C.

    1991-01-01

    The task assignment 3 of the design and validation of digital flight control systems suitable for fly-by-wire applications is studied. Task 3 is associated with formal verification of embedded systems. In particular, results are presented that provide a methodological approach to microprocessor verification. A hierarchical decomposition strategy for specifying microprocessors is also presented. A theory of generic interpreters is presented that can be used to model microprocessor behavior. The generic interpreter theory abstracts away the details of instruction functionality, leaving a general model of what an interpreter does.

  8. Hamilton-Jacobi formalism for tachyon inflation

    NASA Astrophysics Data System (ADS)

    Aghamohammadi, A.; Mohammadi, A.; Golanbari, T.; Saaidi, Kh.

    2014-10-01

    Tachyon inflation is reconsidered by using the recent observational data obtained from Planck-2013 and BICEP2. The Hamilton-Jacobi formalism is picked out as a desirable approach in this work, which allows one to easily obtain the main parameters of the model. The Hubble parameter is supposed as a power-law and exponential function of the scalar field, and each case is considered separately. The constraints on the model, which come from observational data, are explained during the work. The results show a suitable value for the tensor spectral index and an appropriate form of the potential.

  9. Formal scattering theory by an algebraic approach

    NASA Astrophysics Data System (ADS)

    Alhassid, Y.; Levine, R. D.

    1985-02-01

    Formal scattering theory is recast in a Lie-algebraic form. The central result is an algebraic Lippmann-Schwinger equation for the wave operator from which an algebraic form of the Born series (containing only linked terms) is obtained. When a finite Lie algebra is sufficient, The Mo/ller wave operator, on the energy shell, can be solved for explicitly as an element of the corresponding group. The method is illustrated for the separable potential whose relevant algebra is found to be U(1,1).

  10. Formal Verification of Large Software Systems

    NASA Technical Reports Server (NTRS)

    Yin, Xiang; Knight, John

    2010-01-01

    We introduce a scalable proof structure to facilitate formal verification of large software systems. In our approach, we mechanically synthesize an abstract specification from the software implementation, match its static operational structure to that of the original specification, and organize the proof as the conjunction of a series of lemmas about the specification structure. By setting up a different lemma for each distinct element and proving each lemma independently, we obtain the important benefit that the proof scales easily for large systems. We present details of the approach and an illustration of its application on a challenge problem from the security domain

  11. Association Analysis of Alumni Giving: A Formal Concept Analysis

    NASA Astrophysics Data System (ADS)

    Hashemi, Ray R.; Le Blanc, Louis A.; Bahar, Mahmood; Traywick, Bryan

    A large sample (initially 33,000 cases representing a ten percent trial) of university alumni giving records for a large public university in the southwestern United States are analyzed by Formal Concept Analysis (FCA). This likely represents the initially attempt to perform analysis of such data by means of a machine learing technique. The variables employed include the gift amount to the university foundation (UF) as well as traditional demographic variables such as year of graduation, gender, ethnicity, marital status, etc. The UF serves as one of the institution's non-profit, fund-raising organizations. It pursues substantial gifts that are designated for the educational or leadership programs of the giver's choice. Although they process gifts of all sizes, the UF focus is on major gifts and endowments.

  12. Computational Modeling, Formal Analysis, and Tools for Systems Biology

    PubMed Central

    Bartocci, Ezio; Lió, Pietro

    2016-01-01

    As the amount of biological data in the public domain grows, so does the range of modeling and analysis techniques employed in systems biology. In recent years, a number of theoretical computer science developments have enabled modeling methodology to keep pace. The growing interest in systems biology in executable models and their analysis has necessitated the borrowing of terms and methods from computer science, such as formal analysis, model checking, static analysis, and runtime verification. Here, we discuss the most important and exciting computational methods and tools currently available to systems biologists. We believe that a deeper understanding of the concepts and theory highlighted in this review will produce better software practice, improved investigation of complex biological processes, and even new ideas and better feedback into computer science. PMID:26795950

  13. Computational Modeling, Formal Analysis, and Tools for Systems Biology.

    PubMed

    Bartocci, Ezio; Lió, Pietro

    2016-01-01

    As the amount of biological data in the public domain grows, so does the range of modeling and analysis techniques employed in systems biology. In recent years, a number of theoretical computer science developments have enabled modeling methodology to keep pace. The growing interest in systems biology in executable models and their analysis has necessitated the borrowing of terms and methods from computer science, such as formal analysis, model checking, static analysis, and runtime verification. Here, we discuss the most important and exciting computational methods and tools currently available to systems biologists. We believe that a deeper understanding of the concepts and theory highlighted in this review will produce better software practice, improved investigation of complex biological processes, and even new ideas and better feedback into computer science.

  14. Fuzzy and rough formal concept analysis: a survey

    NASA Astrophysics Data System (ADS)

    Poelmans, Jonas; Ignatov, Dmitry I.; Kuznetsov, Sergei O.; Dedene, Guido

    2014-02-01

    Formal Concept Analysis (FCA) is a mathematical technique that has been extensively applied to Boolean data in knowledge discovery, information retrieval, web mining, etc. applications. During the past years, the research on extending FCA theory to cope with imprecise and incomplete information made significant progress. In this paper, we give a systematic overview of the more than 120 papers published between 2003 and 2011 on FCA with fuzzy attributes and rough FCA. We applied traditional FCA as a text-mining instrument to 1072 papers mentioning FCA in the abstract. These papers were formatted in pdf files and using a thesaurus with terms referring to research topics, we transformed them into concept lattices. These lattices were used to analyze and explore the most prominent research topics within the FCA with fuzzy attributes and rough FCA research communities. FCA turned out to be an ideal metatechnique for representing large volumes of unstructured texts.

  15. Design Strategy for a Formally Verified Reliable Computing Platform

    NASA Technical Reports Server (NTRS)

    Butler, Ricky W.; Caldwell, James L.; DiVito, Ben L.

    1991-01-01

    This paper presents a high-level design for a reliable computing platform for real-time control applications. The design tradeoffs and analyses related to the development of a formally verified reliable computing platform are discussed. The design strategy advocated in this paper requires the use of techniques that can be completely characterized mathematically as opposed to more powerful or more flexible algorithms whose performance properties can only be analyzed by simulation and testing. The need for accurate reliability models that can be related to the behavior models is also stressed. Tradeoffs between reliability and voting complexity are explored. In particular, the transient recovery properties of the system are found to be fundamental to both the reliability analysis as well as the "correctness" models.

  16. Provocative Opinion: Descriptive Chemistry.

    ERIC Educational Resources Information Center

    Bent, Henry A.; Bent, Brian E.

    1987-01-01

    Discusses many of the distinctions that chemists draw between theoretical chemistry and descriptive chemistry, along with the tendency for chemical educators to adopt the type of chemistry they feel is most important to teach. Uses examples to argue that theoretical chemistry and descriptive chemistry are, at the bottom line, the same. (TW)

  17. A Descriptive Experiment.

    ERIC Educational Resources Information Center

    Brand, Josef

    1979-01-01

    In this experiment in description, students in a high school honors English class were asked to select a surrealistic painting and capture it in writing. Their compositions were given to art students who tried to reproduce the paintings from the written descriptions. (SJL)

  18. Physics 3204. Course Description.

    ERIC Educational Resources Information Center

    Newfoundland and Labrador Dept. of Education.

    A description of the physics 3204 course in Newfoundland and Labrador is provided. The description includes: (1) statement of purpose, including general objectives of science education; (2) a list of six course objectives; (3) course content for units on sound, light, optical instruments, electrostatics, current electricity, Michael Faraday and…

  19. Job descriptions made easy.

    PubMed

    Miller, Larry

    2014-01-01

    The act of writing a job description can be a daunting and difficult task for many managers. This article focuses on the key concepts of What, How, and Measureable Results as they relate to an employee's job duties. When the answers to these three elements are articulated, they define the core responsibilities of any job that form the basis for an effective job description.

  20. Fluid description of multi-component solar partially ionized plasma

    SciTech Connect

    Khomenko, E. Collados, M.; Vitas, N.; Díaz, A.

    2014-09-15

    We derive self-consistent formalism for the description of multi-component partially ionized solar plasma, by means of the coupled equations for the charged and neutral components for an arbitrary number of chemical species, and the radiation field. All approximations and assumptions are carefully considered. Generalized Ohm's law is derived for the single-fluid and two-fluid formalism. Our approach is analytical with some order-of-magnitude support calculations. After general equations are developed, we particularize to some frequently considered cases as for the interaction of matter and radiation.

  1. Methodology for the description and validation of communication protocols

    NASA Astrophysics Data System (ADS)

    Pattavina, A.; Roveri, A.; Trigila, S.

    1981-12-01

    The models which may be used for the formal description of communication protocols, such as those required for complex computer networks, are analyzed and compared. Two types of models are studied: (1) the abstract automata models including finite state machines, UCLA graphs, Petri nets and formal grammars, and (2) the algorithmic models based on high level programming languages, including sequential languages, such as Pascal, Simula, PL/1, and concurrent languages such as Concurrent Pascal and Chill. Advantages and difficulties are found in both type of models. The evolution of hybrid models is mentionned.

  2. Active plasma resonance spectroscopy: a functional analytic description

    NASA Astrophysics Data System (ADS)

    Lapke, M.; Oberrath, J.; Mussenbrock, T.; Brinkmann, R. P.

    2013-04-01

    The term ‘active plasma resonance spectroscopy’ denotes a class of diagnostic methods which employ the ability of plasmas to resonate on or near the plasma frequency. The basic idea dates back to the early days of discharge physics: a signal in the GHz range is coupled to the plasma via an electrical probe; the spectral response is recorded, and then evaluated with a mathematical model to obtain information on the electron density and other plasma parameters. In recent years, the concept has found renewed interest as a basis of industry compatible plasma diagnostics. This paper analyzes the diagnostic technique in terms of a general description based on functional analytic (or Hilbert Space) methods which hold for arbitrary probe geometries. It is shown that the response function of the plasma-probe system can be expressed as a matrix element of the resolvent of an appropriately defined dynamical operator. A specialization of the formalism to a symmetric probe design is given, as well as an interpretation in terms of a lumped circuit model consisting of series resonance circuits. We present ideas for an optimized probe design based on geometric and electrical symmetry.

  3. On Formal Analysis as Design Research.

    ERIC Educational Resources Information Center

    Brown, Denise Scott

    1979-01-01

    A series of planning-like studios are described that are both interdisciplinary and strongly structured to introduce architects to the nonarchitectural subject matter of urban design and planning. The Las Vegas and Levittown studios produced descriptions of the places studied and analyses of the physical and symbolic requirements they fulfilled.…

  4. 20 CFR 702.336 - Formal hearings; new issues.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Formal hearings; new issues. 702.336 Section... Adjudication Procedures Formal Hearings § 702.336 Formal hearings; new issues. (a) If, during the course of the... considered, the hearing may be expanded to include the new issue. If in the opinion of the administrative...

  5. "Passing It On": Beyond Formal or Informal Pedagogies

    ERIC Educational Resources Information Center

    Cain, Tim

    2013-01-01

    Informal pedagogies are a subject of debate in music education, and there is some evidence of teachers abandoning formal pedagogies in favour of informal ones. This article presents a case of one teacher's formal pedagogy and theorises it by comparing it with a case of informal pedagogy. The comparison reveals affordances of formal pedagogies…

  6. How External Institutions Penetrate Schools through Formal and Informal Leaders

    ERIC Educational Resources Information Center

    Sun, Min; Frank, Kenneth A.; Penuel, William R.; Kim, Chong Min

    2013-01-01

    Purposes: This study investigates the role of formal and informal leaders in the diffusion of external reforms into schools and to teachers' practices. Formal leaders are designated by their roles in the formal organization of the school (e.g., principals, department chairs, and instructional coaches) and informal leaders refer to those who…

  7. 7 CFR 1726.201 - Formal competitive bidding.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false Formal competitive bidding. 1726.201 Section 1726.201... AGRICULTURE ELECTRIC SYSTEM CONSTRUCTION POLICIES AND PROCEDURES Procurement Procedures § 1726.201 Formal competitive bidding. Formal competitive bidding is used for distribution, transmission, and...

  8. Is Lawson's Classroom Test of Formal Reasoning Valid?

    ERIC Educational Resources Information Center

    Pratt, C.; Hacker, R. G.

    1984-01-01

    A unidimensional latent trait model was used to test a single-factor hypothesis of the Lawson Classroom Test of Formal Reasoning. The test failed to provide a valid measure of formal reasoning. This was a result of test format which neglected aspects of formal reasoning emphasized by Inhelder and Piaget. (Author/DWH)

  9. 25 CFR 151.14 - Formalization of acceptance.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Formalization of acceptance. 151.14 Section 151.14 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER LAND ACQUISITIONS § 151.14 Formalization of acceptance. Formal acceptance of land in trust status shall be accomplished by the issuance...

  10. 49 CFR 1111.1 - Content of formal complaints; joinder.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 8 2010-10-01 2010-10-01 false Content of formal complaints; joinder. 1111.1... § 1111.1 Content of formal complaints; joinder. (a) General. A formal complaint must contain the correct... language the facts upon which it is based. It should include specific reference to pertinent...

  11. Generalized Boltzmann formalism for oscillating neutrinos

    SciTech Connect

    Strack, P.; Burrows, A.

    2005-05-01

    In the standard approaches to neutrino transport in the simulation of core-collapse supernovas, one will often start from the classical Boltzmann equation for the neutrino's spatial, temporal, and spectral evolution. For each neutrino species, and its antiparticle, the classical density in phase space, or the associated specific intensity, will be calculated as a function of time. The neutrino radiation is coupled to matter by source and sink terms on the 'right-hand side' of the transport equation and together with the equations of hydrodynamics this set of coupled partial differential equations for classical densities describes, in principle, the evolution of core collapse and explosion. However, with the possibility of neutrino oscillations between species, a purely quantum-physical effect, how to generalize this set of Boltzmann equations for classical quantities to reflect oscillation physics has not been clear. To date, the formalisms developed have retained the character of quantum operator physics involving complex quantities and have not been suitable for easy incorporation into standard supernova codes. In this paper, we derive generalized Boltzmann equations for quasiclassical, real-valued phase-space densities that retain all the standard oscillation phenomenology, including the matter-enhanced resonant flavor conversion (Mikheev-Smirnov-Wolfenstein effect), neutrino self-interactions, and the interplay between decohering matter coupling and flavor oscillations. With this formalism, any code(s) that can now handle the solution of the classical Boltzmann or transport equation can easily be generalized to include neutrino oscillations in a quantum-physically consistent fashion.

  12. Formal linguistics as a cue to demographic history.

    PubMed

    Longobardi, Giuseppe; Ceolin, Andrea; Ecay, Aaron; Ghirotto, Silvia; Guardiano, Cristina; Irimia, Monica-Alexandrina; Michelioudakis, Dimitris; Radkevich, Nina; Pettener, Davide; Luiselli, Donata; Barbujani, Guido

    2016-06-20

    Beyond its theoretical success, the development of molecular genetics has brought about the possibility of extraordinary progress in the study of classification and in the inference of the evolutionary history of many species and populations. A major step forward was represented by the availability of extremely large sets of molecular data suited to quantitative and computational treatments. In this paper, we argue that even in cognitive sciences, purely theoretical progress in a discipline such as linguistics may have analogous impact. Thus, exactly on the model of molecular biology, we propose to unify two traditionally unrelated lines of linguistic investigation: 1) the formal study of syntactic variation (parameter theory) in the biolinguistic program; 2) the reconstruction of relatedness among languages (phylogenetic taxonomy). The results of our linguistic analysis have thus been plotted against data from population genetics and the correlations have turned out to be largely significant: given a non-trivial set of languages/populations, the description of their variation provided by the comparison of systematic parametric analysis and molecular anthropology informatively recapitulates their history and relationships. As a result, we can claim that the reality of some parametric model of the language faculty and language acquisition/transmission (more broadly of generative grammar) receives strong and original support from its historical heuristic power. Then, on these grounds, we can begin testing Darwin's prediction that, when properly generated, the trees of human populations and of their languages should eventually turn out to be significantly parallel. PMID:27081010

  13. Formal linguistics as a cue to demographic history.

    PubMed

    Longobardi, Giuseppe; Ceolin, Andrea; Ecay, Aaron; Ghirotto, Silvia; Guardiano, Cristina; Irimia, Monica-Alexandrina; Michelioudakis, Dimitris; Radkevich, Nina; Pettener, Davide; Luiselli, Donata; Barbujani, Guido

    2016-06-20

    Beyond its theoretical success, the development of molecular genetics has brought about the possibility of extraordinary progress in the study of classification and in the inference of the evolutionary history of many species and populations. A major step forward was represented by the availability of extremely large sets of molecular data suited to quantitative and computational treatments. In this paper, we argue that even in cognitive sciences, purely theoretical progress in a discipline such as linguistics may have analogous impact. Thus, exactly on the model of molecular biology, we propose to unify two traditionally unrelated lines of linguistic investigation: 1) the formal study of syntactic variation (parameter theory) in the biolinguistic program; 2) the reconstruction of relatedness among languages (phylogenetic taxonomy). The results of our linguistic analysis have thus been plotted against data from population genetics and the correlations have turned out to be largely significant: given a non-trivial set of languages/populations, the description of their variation provided by the comparison of systematic parametric analysis and molecular anthropology informatively recapitulates their history and relationships. As a result, we can claim that the reality of some parametric model of the language faculty and language acquisition/transmission (more broadly of generative grammar) receives strong and original support from its historical heuristic power. Then, on these grounds, we can begin testing Darwin's prediction that, when properly generated, the trees of human populations and of their languages should eventually turn out to be significantly parallel.

  14. Formal Methods Specification and Analysis Guidebook for the Verification of Software and Computer Systems. Volume 2; A Practitioner's Companion

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This guidebook, the second of a two-volume series, is intended to facilitate the transfer of formal methods to the avionics and aerospace community. The 1st volume concentrates on administrative and planning issues [NASA-95a], and the second volume focuses on the technical issues involved in applying formal methods to avionics and aerospace software systems. Hereafter, the term "guidebook" refers exclusively to the second volume of the series. The title of this second volume, A Practitioner's Companion, conveys its intent. The guidebook is written primarily for the nonexpert and requires little or no prior experience with formal methods techniques and tools. However, it does attempt to distill some of the more subtle ingredients in the productive application of formal methods. To the extent that it succeeds, those conversant with formal methods will also nd the guidebook useful. The discussion is illustrated through the development of a realistic example, relevant fragments of which appear in each chapter. The guidebook focuses primarily on the use of formal methods for analysis of requirements and high-level design, the stages at which formal methods have been most productively applied. Although much of the discussion applies to low-level design and implementation, the guidebook does not discuss issues involved in the later life cycle application of formal methods.

  15. Formal analytical modeling of blog content as personal narrative

    NASA Astrophysics Data System (ADS)

    Coombs, Michael J.; Jaenisch, Holger M.; Handley, James W.

    2008-04-01

    This paper contrasts two techniques for analyzing blog content and making use of this information to model blog content. One method uses classical text content and analysis presented for human interpretation. The second method relies on a data mined list of descriptive words characterizing the blogs. We examine the use of different data mining tools, Kryltech's "Subject Search Summarizer", Leximancer, and QUEST, to provide orthogonal and independently generated key word lists. These lists are then converted into Data Models, enabling mathematical modeling of blog content.

  16. General formalism for the efficient calculation of derivatives of EM frequency-domain responses and derivatives of the misfit

    NASA Astrophysics Data System (ADS)

    Pankratov, Oleg; Kuvshinov, Alexei

    2010-04-01

    Electromagnetic (EM) studies of the Earth have advanced significantly over the past few years. This progress was driven, in particular, by new developments in the methods of 3-D inversion of EM data. Due to the large scale of the 3-D EM inverse problems, iterative gradient-type methods have mostly been employed. In these methods one has to calculate multiple times the gradient of the penalty function-a sum of misfit and regularization terms-with respect to the model parameters. However, even with modern computational capabilities the straightforward calculation of the misfit gradients based on numerical differentiation is extremely time consuming. Much more efficient and elegant way to calculate the gradient of the misfit is provided by the so-called `adjoint' approach. This is now widely used in many 3-D numerical schemes for inverting EM data of different types and origin. It allows the calculation of the misfit gradient for the price of only a few additional forward calculations. In spite of its popularity we did not find in the literature any general description of the approach, which would allow researchers to apply this methodology in a straightforward manner to their scenario of interest. In the paper, we present formalism for the efficient calculation of the derivatives of EM frequency-domain responses and the derivatives of the misfit with respect to variations of 3-D isotropic/anisotropic conductivity. The approach is rather general; it works with single-site responses, multisite responses and responses that include spatial derivatives of EM field. The formalism also allows for various types of parametrization of the 3-D conductivity distribution. Using this methodology one can readily obtain appropriate formulae for the specific sounding methods. To illustrate the concept we provide such formulae for a number of EM techniques: geomagnetic depth sounding (GDS), conventional and generalized magnetotellurics, the magnetovariational method, horizontal

  17. Indigenous Knowledge and Education from the Quechua Community to School: Beyond the Formal/Non-Formal Dichotomy

    ERIC Educational Resources Information Center

    Sumida Huaman, Elizabeth; Valdiviezo, Laura Alicia

    2014-01-01

    In this article, we propose to approach Indigenous education beyond the formal/non-formal dichotomy. We argue that there is a critical need to conscientiously include Indigenous knowledge in education processes from the school to the community; particularly, when formal systems exclude Indigenous cultures and languages. Based on ethnographic…

  18. Guidance for Using Formal Methods in a Certification Context

    NASA Technical Reports Server (NTRS)

    Brown, Duncan; Delseny, Herve; Hayhurst, Kelly; Wiels, Virginie

    2010-01-01

    This paper discusses some of the challenges to using formal methods in a certification context and describes the effort by the Formal Methods Subgroup of RTCA SC-205/EUROCAE WG-71 to propose guidance to make the use of formal methods a recognized approach. This guidance, expected to take the form of a Formal Methods Technical Supplement to DO-178C/ED-12C, is described, including the activities that are needed when using formal methods, new or modified objectives with respect to the core DO-178C/ED-12C document, and evidence needed for meeting those objectives.

  19. Extended Cahill-Glauber formalism for finite-dimensional spaces. II. Applications in quantum tomography and quantum teleportation

    SciTech Connect

    Marchiolli, Marcelo A.; Ruzzi, Maurizio; Galetti, Diogenes

    2005-10-15

    By means of a mod(N)-invariant operator basis, s-parametrized phase-space functions associated with bounded operators in a finite-dimensional Hilbert space are introduced in the context of the extended Cahill-Glauber formalism, and their properties are discussed in details. The discrete Glauber-Sudarshan, Wigner, and Husimi functions emerge from this formalism as specific cases of s-parametrized phase-space functions where, in particular, a hierarchical process among them is promptly established. In addition, a phase-space description of quantum tomography and quantum teleportation is presented and new results are obtained.

  20. Rethinking Formalisms in Formal Education. Working Paper No. 2005-11

    ERIC Educational Resources Information Center

    Nathan, Mitchell J.

    2005-01-01

    In this paper, I explore two beliefs about learning and teaching that I argue are prevalent among educators. The first is the belief that subject matter expertise is sufficient for success in teaching. The second belief is that to learn a specific content area, one needs to begin with an understanding of the formal structure and abstract…

  1. Analytical Formalism for the Interaction of Two-Level Quantum Systems with Metal Nanoresonators

    NASA Astrophysics Data System (ADS)

    Yang, Jianji; Perrin, Mathias; Lalanne, Philippe

    2015-04-01

    Hybrid systems made of quantum emitters and plasmonic nanoresonators offer a unique platform to implement artificial atoms with completely novel optical responses that are not available otherwise. However, their theoretical analysis is difficult, and since many degrees of freedom have to be explored, engineering their optical properties remains challenging. Here, we propose a new formalism that removes most limitations encountered in previous analytical treatments and allows a flexible and efficient study of complex nanoresonators with arbitrary shapes in an almost fully analytically way. The formalism brings accurate closed-form expressions for the hybrid-system optical response and provides an intuitive description based on the coupling between the quantum emitters and the resonance modes of the nanoresonator. The ability to quickly predict light-scattering properties of hybrid systems paves the way to a deep exploration of their fascinating properties and may enable rapid optimization of quantum plasmonic metamaterials or quantum information devices.

  2. Formalisms for Specifying Markovian Population Models

    NASA Astrophysics Data System (ADS)

    Henzinger, Thomas A.; Jobstmann, Barbara; Wolf, Verena

    We compare several languages for specifying Markovian population models such as queuing networks and chemical reaction networks. These languages —matrix descriptions, stochastic Petri nets, stoichiometric equations, stochastic process algebras, and guarded command models— all describe continuous-time Markov chains, but they differ according to important properties, such as compositionality, expressiveness and succinctness, executability, ease of use, and the support they provide for checking the well-formedness of a model and for analyzing a model.

  3. Multilevel structured program design: formalization and applications

    SciTech Connect

    Glushkov, V.M.; Tseitlin, G.E.; Yushchenko, E.L.

    1981-07-01

    The authors present the conception of structured design grammars (SDG), which provide the basis for the MSPD method. A classification of program development methods according to top-down, bottom-up, and mixed strategy is proposed. The SDG formalism makes it possible to consider the problem of multilevel partial program verification, program transformation, and documentation generation during program development and subsequent maintenance. The MSPD method is demonstrated in application to a number of program design projects. They develop the arsenal of structured programming using MSPD method. Language and software tools constituting the basis of structured programming are considered. The problem of multilevel optimizing translation is treated in the context of the mul'tiprotsessist system oriented to automatic structured parallel programming by the MSPD method. Applications of the MSPD method to symbolic processing are considered. The process of structured design of the partran system and of software modules for mini- and microcomputers is described. 70 references.

  4. Formalization of Embodied Sensorimotor Coupling System

    NASA Astrophysics Data System (ADS)

    Nakajima, Kohei

    2008-10-01

    Theoretical conception of an active behavior of the system is one of the most challengeable topics in complex systems research. Recently, especially in the fields of robotics and artificial intelligence, there broadly exists the study to understand the interface between the system and its environment by creating an autonomous agent that carries a sensorimotor coupling. In this paper, an embodied sensorimotor coupling system is discussed. Applying a generative pointer, the system is formalized to contain an intrinsic discrepancy induced by heterarichical duality in a flow construction by using category theory. In the system, the body plays a positive role as a dynamical mediator, or interface, between two conflicting layers, a relational layers and a constituent layers. As a result, it induces a structural change of the system itself. Implementing the construction to a Braitenberg type vehicle, we observed dynamical changes of system parameters and its behavior revealed various motion patterns compared with the conventional sensorimotor coupling system.

  5. Formalizing Linguistic Conventions for Conceptual Models

    NASA Astrophysics Data System (ADS)

    Becker, Jörg; Delfmann, Patrick; Herwig, Sebastian; Lis, Łukasz; Stein, Armin

    A precondition for the appropriate analysis of conceptual models is not only their syntactic correctness but also their semantic comparability. Assuring comparability is challenging especially when models are developed by different persons. Empirical studies show that such models can vary heavily, especially in model element naming, even if they express the same issue. In contrast to most ontology-driven approaches proposing the resolution of these differences ex-post, we introduce an approach that avoids naming differences in conceptual models already during modeling. Therefore we formalize naming conventions combining domain thesauri and phrase structures based on a lin-guistic grammar. This allows for guiding modelers automatically during the modeling process using standardized labels for model elements. Our approach is generic, making it applicable for any modeling language.

  6. Higher-order generalized hydrodynamics: Foundations within a nonequilibrium statistical ensemble formalism.

    PubMed

    Silva, Carlos A B; Rodrigues, Clóves G; Ramos, J Galvão; Luzzi, Roberto

    2015-06-01

    Construction, in the framework of a nonequilibrium statistical ensemble formalism, of a higher-order generalized hydrodynamics, also referred to as mesoscopic hydrothermodynamics, that is, covering phenomena involving motion of fluids displaying variations short in space and fast in time-unrestricted values of Knudsen numbers, is presented. In that way, an approach is provided enabling the coupling and simultaneous treatment of the kinetics and hydrodynamic levels of descriptions. It is based on a complete thermostatistical approach in terms of the densities of matter and energy and their fluxes of all orders covering systems arbitrarily driven away from equilibrium. The set of coupled nonlinear integrodifferential hydrodynamic equations is derived. They are the evolution equations of the Gradlike moments of all orders, derived from a generalized kinetic equation built in the framework of the nonequilibrium statistical ensemble formalism. For illustration, the case of a system of particles embedded in a fluid acting as a thermal bath is fully described. The resulting enormous set of coupled evolution equations is of unmanageable proportions, thus requiring in practice to introduce an appropriate description using the smallest possible number of variables. We have obtained a hierarchy of Maxwell times, associated to the set of all the higher-order fluxes, which have a particular relevance in the process of providing criteria for establishing the contraction of description. PMID:26172796

  7. Higher-order generalized hydrodynamics: Foundations within a nonequilibrium statistical ensemble formalism.

    PubMed

    Silva, Carlos A B; Rodrigues, Clóves G; Ramos, J Galvão; Luzzi, Roberto

    2015-06-01

    Construction, in the framework of a nonequilibrium statistical ensemble formalism, of a higher-order generalized hydrodynamics, also referred to as mesoscopic hydrothermodynamics, that is, covering phenomena involving motion of fluids displaying variations short in space and fast in time-unrestricted values of Knudsen numbers, is presented. In that way, an approach is provided enabling the coupling and simultaneous treatment of the kinetics and hydrodynamic levels of descriptions. It is based on a complete thermostatistical approach in terms of the densities of matter and energy and their fluxes of all orders covering systems arbitrarily driven away from equilibrium. The set of coupled nonlinear integrodifferential hydrodynamic equations is derived. They are the evolution equations of the Gradlike moments of all orders, derived from a generalized kinetic equation built in the framework of the nonequilibrium statistical ensemble formalism. For illustration, the case of a system of particles embedded in a fluid acting as a thermal bath is fully described. The resulting enormous set of coupled evolution equations is of unmanageable proportions, thus requiring in practice to introduce an appropriate description using the smallest possible number of variables. We have obtained a hierarchy of Maxwell times, associated to the set of all the higher-order fluxes, which have a particular relevance in the process of providing criteria for establishing the contraction of description.

  8. Applying formal methods and object-oriented analysis to existing flight software

    NASA Technical Reports Server (NTRS)

    Cheng, Betty H. C.; Auernheimer, Brent

    1993-01-01

    Correctness is paramount for safety-critical software control systems. Critical software failures in medical radiation treatment, communications, and defense are familiar to the public. The significant quantity of software malfunctions regularly reported to the software engineering community, the laws concerning liability, and a recent NRC Aeronautics and Space Engineering Board report additionally motivate the use of error-reducing and defect detection software development techniques. The benefits of formal methods in requirements driven software development ('forward engineering') is well documented. One advantage of rigorously engineering software is that formal notations are precise, verifiable, and facilitate automated processing. This paper describes the application of formal methods to reverse engineering, where formal specifications are developed for a portion of the shuttle on-orbit digital autopilot (DAP). Three objectives of the project were to: demonstrate the use of formal methods on a shuttle application, facilitate the incorporation and validation of new requirements for the system, and verify the safety-critical properties to be exhibited by the software.

  9. BASIC Tools: Structured Programming Techniques in BASIC.

    ERIC Educational Resources Information Center

    Moyer, Patrick C.

    1985-01-01

    Structured programing is an attempt to formalize the logic and structure of computer programs. Examples of structured programing techniques in BASIC are provided. Two major disadvantages of this style of programing for the personal user are noted. (JN)

  10. Exciton scattering approach for branched conjugated molecules and complexes. I. Formalism.

    PubMed

    Wu, Chao; Malinin, Sergey V; Tretiak, Sergei; Chernyak, Vladimir Y

    2008-11-01

    We develop a formalism for the exciton scattering (ES) approach to calculation of the excited state electronic structure of branched conjugated polymers with insignificant numerical expense. The ES approach attributes electronic excitations in quasi-one-dimensional molecules to standing waves formed by the scattering of quantum quasiparticles. We derive the phenomenology from the microscopic description in terms of many-electron excitations. The presented model can be used to compute both excited state frequencies and transition dipoles in large molecules after the ES ingredients are extracted from smaller molecular fragments. PMID:19045337

  11. Turning Informal Thesauri Into Formal Ontologies: A Feasibility Study on Biomedical Knowledge re-Use

    PubMed Central

    2003-01-01

    This paper reports a large-scale knowledge conversion and curation experiment. Biomedical domain knowledge from a semantically weak and shallow terminological resource, the UMLS, is transformed into a rigorous description logics format. This way, the broad coverage of the UMLS is combined with inference mechanisms for consistency and cycle checking. They are the key to proper cleansing of the knowledge directly imported from the UMLS, as well as subsequent updating, maintenance and refinement of large knowledge repositories. The emerging biomedical knowledge base currently comprises more than 240 000 conceptual entities and hence constitutes one of the largest formal knowledge repositories ever built. PMID:18629112

  12. One-pion exchange current effects on magnetic form factor in the relativistic formalism

    NASA Astrophysics Data System (ADS)

    Zhang, Cun; Liu, Jian; Ren, Zhongzhou

    2016-08-01

    One-pion exchange current effects on the magnetic form factors of some odd nuclei are studied in the relativistic formalism. The Dirac wave functions of nucleons are calculated from the relativistic mean-field theory. After fitting to experimental data by quenching factors, it is found that taking the one-pion exchange currents into account gives a better description of the magnetic form factor. The root-mean-square radii of the valance nucleon orbits are also calculated in RMF model, which coincide with experimental radii extracted with meson exchange current corrections.

  13. A formal language for the specification and verification of synchronous and asynchronous circuits

    NASA Technical Reports Server (NTRS)

    Russinoff, David M.

    1993-01-01

    A formal hardware description language for the intended application of verifiable asynchronous communication is described. The language is developed within the logical framework of the Nqthm system of Boyer and Moore and is based on the event-driven behavioral model of VHDL, including the basic VHDL signal propagation mechanisms, the notion of simulation deltas, and the VHDL simulation cycle. A core subset of the language corresponds closely with a subset of VHDL and is adequate for the realistic gate-level modeling of both combinational and sequential circuits. Various extensions to this subset provide means for convenient expression of behavioral circuit specifications.

  14. Nuclear field theory description of the three-body system 11Li

    NASA Astrophysics Data System (ADS)

    Broglia, R. A.; Barranco, F.; Coló, G.; Vigezzi, E.; Bortignon, P. F.; Gori, G.; Terasaki, J.

    2002-04-01

    The three-body description of two-neutron halo systems is extended to allow for core polarization taking into account the associated effects of mass-renormalization (single-particle motion) and induced interaction (density dependent pairing force) in terms of the particle-vibration coupling formalism. This formalism is applied to 10Li and 11Li. Theory reproduces most of the attractive features of Faddeev type calculations providing, in addition, an overall account of the experimental findings. .

  15. Connecting Formal and Informal Learning Experiences

    NASA Astrophysics Data System (ADS)

    O'Mahony, Timothy Kieran

    The learning study reports on part of a larger project being lead by the author. In this dissertation I explore one goal of this project---to understand effects on student learning outcomes as a function of using different methods for connecting out-of-school experiential learning with formal school-based instruction. There is a long history of assuming that "experience is the best teacher"(e.g. Aristotle, 360 BC; Dewey, 1934; Kolb, 1997; Pliny, AD 77). As a practical geographer I endorsed that assumption throughout my teaching career, paying attention to local topography, physical features, and natural resources in the geographic hinterland. I was particularly interested in understanding the impact of the physical landscape on humankind, and reciprocally, noting humankind's widespread impressions on the natural world. Until I began this research project, I assumed that everyone else paid a similar attention to immediate surroundings. The work that I describe in this dissertation emerges out of a conviction that there are many degrees of truth to the idea that experience is a great teacher. Its effectiveness seems to depend on how one's "experience" is mediated, and how "learning from it" is defined. This motivated me to think about design principles for linking people's experiences to learning. I began to explore, experimentally, how I might enhance people's abilities to notice, represent, and discuss their experiences in order to better learn from them. This study investigated how different ways of connecting outdoor learning experiences to formal schooling impacts students' performance. I studied high-school students in outdoor settings as they engaged in evocative issues of learning pertaining to consequential everyday life encounters. Different kinds of "expert mediation" were introduced and tested as the students engaged in investigative activities around the science of dam removal and habitat restoration. I measured outcomes with the aid of pre- and

  16. From Informal Safety-Critical Requirements to Property-Driven Formal Validation

    NASA Technical Reports Server (NTRS)

    Cimatti, Alessandro; Roveri, Marco; Susi, Angelo; Tonetta, Stefano

    2008-01-01

    Most of the efforts in formal methods have historically been devoted to comparing a design against a set of requirements. The validation of the requirements themselves, however, has often been disregarded, and it can be considered a largely open problem, which poses several challenges. The first challenge is given by the fact that requirements are often written in natural language, and may thus contain a high degree of ambiguity. Despite the progresses in Natural Language Processing techniques, the task of understanding a set of requirements cannot be automatized, and must be carried out by domain experts, who are typically not familiar with formal languages. Furthermore, in order to retain a direct connection with the informal requirements, the formalization cannot follow standard model-based approaches. The second challenge lies in the formal validation of requirements. On one hand, it is not even clear which are the correctness criteria or the high-level properties that the requirements must fulfill. On the other hand, the expressivity of the language used in the formalization may go beyond the theoretical and/or practical capacity of state-of-the-art formal verification. In order to solve these issues, we propose a new methodology that comprises of a chain of steps, each supported by a specific tool. The main steps are the following. First, the informal requirements are split into basic fragments, which are classified into categories, and dependency and generalization relationships among them are identified. Second, the fragments are modeled using a visual language such as UML. The UML diagrams are both syntactically restricted (in order to guarantee a formal semantics), and enriched with a highly controlled natural language (to allow for modeling static and temporal constraints). Third, an automatic formal analysis phase iterates over the modeled requirements, by combining several, complementary techniques: checking consistency; verifying whether the

  17. Formal verification of an oral messages algorithm for interactive consistency

    NASA Technical Reports Server (NTRS)

    Rushby, John

    1992-01-01

    The formal specification and verification of an algorithm for Interactive Consistency based on the Oral Messages algorithm for Byzantine Agreement is described. We compare our treatment with that of Bevier and Young, who presented a formal specification and verification for a very similar algorithm. Unlike Bevier and Young, who observed that 'the invariant maintained in the recursive subcases of the algorithm is significantly more complicated than is suggested by the published proof' and who found its formal verification 'a fairly difficult exercise in mechanical theorem proving,' our treatment is very close to the previously published analysis of the algorithm, and our formal specification and verification are straightforward. This example illustrates how delicate choices in the formulation of the problem can have significant impact on the readability of its formal specification and on the tractability of its formal verification.

  18. Formal Methods Applications in Air Transportation

    NASA Technical Reports Server (NTRS)

    Farley, Todd

    2009-01-01

    The U.S. air transportation system is the most productive in the world, moving far more people and goods than any other. It is also the safest system in the world, thanks in part to its venerable air traffic control system. But as demand for air travel continues to grow, the air traffic control system s aging infrastructure and labor-intensive procedures are impinging on its ability to keep pace with demand. And that impinges on the growth of our economy. Air traffic control modernization has long held the promise of a more efficient air transportation system. Part of NASA s current mission is to develop advanced automation and operational concepts that will expand the capacity of our national airspace system while still maintaining its excellent record for safety. It is a challenging mission, as efforts to modernize have, for decades, been hamstrung by the inability to assure safety to the satisfaction of system operators, system regulators, and/or the traveling public. In this talk, we ll provide a brief history of air traffic control, focusing on the tension between efficiency and safety assurance, and the promise of formal methods going forward.

  19. Fostering Formal Commutativity Knowledge with Approximate Arithmetic.

    PubMed

    Hansen, Sonja Maria; Haider, Hilde; Eichler, Alexandra; Godau, Claudia; Frensch, Peter A; Gaschler, Robert

    2015-01-01

    How can we enhance the understanding of abstract mathematical principles in elementary school? Different studies found out that nonsymbolic estimation could foster subsequent exact number processing and simple arithmetic. Taking the commutativity principle as a test case, we investigated if the approximate calculation of symbolic commutative quantities can also alter the access to procedural and conceptual knowledge of a more abstract arithmetic principle. Experiment 1 tested first graders who had not been instructed about commutativity in school yet. Approximate calculation with symbolic quantities positively influenced the use of commutativity-based shortcuts in formal arithmetic. We replicated this finding with older first graders (Experiment 2) and third graders (Experiment 3). Despite the positive effect of approximation on the spontaneous application of commutativity-based shortcuts in arithmetic problems, we found no comparable impact on the application of conceptual knowledge of the commutativity principle. Overall, our results show that the usage of a specific arithmetic principle can benefit from approximation. However, the findings also suggest that the correct use of certain procedures does not always imply conceptual understanding. Rather, the conceptual understanding of commutativity seems to lag behind procedural proficiency during elementary school. PMID:26560311

  20. An enantioselective formal synthesis of montelukast sodium.

    PubMed

    Bollikonda, Satyanarayana; Mohanarangam, Saravanan; Jinna, Rajender Reddy; Kandirelli, Venkata Kiran Kumar; Makthala, Laxman; Sen, Saikat; Chaplin, David A; Lloyd, Richard C; Mahoney, Thomas; Dahanukar, Vilas Hareshwar; Oruganti, Srinivas; Fox, Martin E

    2015-04-17

    A formal synthesis of the antiasthma drug montelukast sodium is described, wherein the key chiral diol intermediate was accessed with greater convergence of the C-C bond-forming steps as compared to previous routes. Improved synthetic efficiency was achieved by deploying homogeneous metal-based catalysis in two pivotal steps. In the first, a tandem Mizoroki-Heck reaction and double-bond isomerization between a previously known allyl alcohol intermediate and a hindered 2-(2-halophenyl)propan-2-ol secured direct access to the 3-(2-(2-hydroxypropan-2-yl)phenyl)-1-phenylpropan-1-one moiety in the product. In the second step, asymmetric hydrogenation of the ketone functionality in the Mizoroki-Heck reaction product provided a convenient method to introduce the benzylic alcohol chiral center and obtain the desired chiral diol precursor of montelukast sodium. A detailed catalyst screening led to the identification of ((R)-Xyl-BINAP)((R,R)-DPEN)RuCl2 as a catalyst that afforded an enantioselectivity of 99% ee in the hydrogenation step on a multigram lab scale at a molar substrate:catalyst loading of 5000:1. PMID:25807000

  1. Fostering Formal Commutativity Knowledge with Approximate Arithmetic

    PubMed Central

    Hansen, Sonja Maria; Haider, Hilde; Eichler, Alexandra; Godau, Claudia; Frensch, Peter A.; Gaschler, Robert

    2015-01-01

    How can we enhance the understanding of abstract mathematical principles in elementary school? Different studies found out that nonsymbolic estimation could foster subsequent exact number processing and simple arithmetic. Taking the commutativity principle as a test case, we investigated if the approximate calculation of symbolic commutative quantities can also alter the access to procedural and conceptual knowledge of a more abstract arithmetic principle. Experiment 1 tested first graders who had not been instructed about commutativity in school yet. Approximate calculation with symbolic quantities positively influenced the use of commutativity-based shortcuts in formal arithmetic. We replicated this finding with older first graders (Experiment 2) and third graders (Experiment 3). Despite the positive effect of approximation on the spontaneous application of commutativity-based shortcuts in arithmetic problems, we found no comparable impact on the application of conceptual knowledge of the commutativity principle. Overall, our results show that the usage of a specific arithmetic principle can benefit from approximation. However, the findings also suggest that the correct use of certain procedures does not always imply conceptual understanding. Rather, the conceptual understanding of commutativity seems to lag behind procedural proficiency during elementary school. PMID:26560311

  2. A Hamilton Jacobi formalism for thermodynamics

    NASA Astrophysics Data System (ADS)

    Rajeev, S. G.

    2008-09-01

    We show that classical thermodynamics has a formulation in terms of Hamilton-Jacobi theory, analogous to mechanics. Even though the thermodynamic variables come in conjugate pairs such as pressure/volume or temperature/entropy, the phase space is odd-dimensional. For a system with n thermodynamic degrees of freedom it is 2n+1-dimensional. The equations of state of a substance pick out an n-dimensional submanifold. A family of substances whose equations of state depend on n parameters define a hypersurface of co-dimension one. This can be described by the vanishing of a function which plays the role of a Hamiltonian. The ordinary differential equations (characteristic equations) defined by this function describe a dynamical system on the hypersurface. Its orbits can be used to reconstruct the equations of state. The 'time' variable associated to this dynamics is related to, but is not identical to, entropy. After developing this formalism on well-grounded systems such as the van der Waals gases and the Curie-Weiss magnets, we derive a Hamilton-Jacobi equation for black hole thermodynamics in General Relativity. The cosmological constant appears as a constant of integration in this picture.

  3. The Lagrangian-Hamiltonian formalism for higher order field theories

    NASA Astrophysics Data System (ADS)

    Vitagliano, Luca

    2010-06-01

    We generalize the Lagrangian-Hamiltonian formalism of Skinner and Rusk to higher order field theories on fiber bundles. As a byproduct we solve the long standing problem of defining, in a coordinate free manner, a Hamiltonian formalism for higher order Lagrangian field theories. Namely, our formalism does only depend on the action functional and, therefore, unlike previously proposed ones, is free from any relevant ambiguity.

  4. A formalism for the calculus of variations with spinors

    NASA Astrophysics Data System (ADS)

    Bäckdahl, Thomas; Valiente Kroon, Juan A.

    2016-02-01

    We develop a frame and dyad gauge-independent formalism for the calculus of variations of functionals involving spinorial objects. As a part of this formalism, we define a modified variation operator which absorbs frame and spin dyad gauge terms. This formalism is applicable to both the standard spacetime (i.e., SL(2, ℂ)) 2-spinors as well as to space (i.e., SU(2, ℂ)) 2-spinors. We compute expressions for the variations of the connection and the curvature spinors.

  5. Stability formalism of a flowing two-fluid plasma

    NASA Astrophysics Data System (ADS)

    Yamada, Hideaki; Katano, Takayuki; Ishida, Akio; Steinhauer, Loren C.

    2003-04-01

    An improved formalism for a stability analysis of flowing two-fluid equilibria with constant density is developed. The two-fluid formalism, in which the generalized vorticity of each species is introduced as characteristic quantity, extends the usual single-fluid formalism. A new relation between the perturbed generalized vorticity and the displacement is found for each species. The spectral formalism is developed for stability of axisymmetric equilibrium. The missing elements in the single-fluid analysis of Frieman and Rotenberg [Rev. Mod. Phys. 32, 898 (1960)] are identified.

  6. A Formal Semantics for the SRI Hierarchical Program Design Methodology

    NASA Technical Reports Server (NTRS)

    Boyer, R. S.; Moore, J. S.

    1983-01-01

    A formal statement of what it means to use (a subset of) the methodology is presented. It is formally defined that some specified module exists and what it means to say that another module is paid correctly implemented on top of it. No attention is to motivation, either of the methodology or of the formal development of it. Concentration is entirely upon mathematical succinctness and precision. A discussion is presented of how to use certain INTERLISP programs which implement the formal definitions. Among these are a program which generates Floyd like verification conditions sufficient to imply the correctness of a module implementation.

  7. Probability density function formalism for optical coherence tomography signal analysis: a controlled phantom study.

    PubMed

    Weatherbee, Andrew; Sugita, Mitsuro; Bizheva, Kostadinka; Popov, Ivan; Vitkin, Alex

    2016-06-15

    The distribution of backscattered intensities as described by the probability density function (PDF) of tissue-scattered light contains information that may be useful for tissue assessment and diagnosis, including characterization of its pathology. In this Letter, we examine the PDF description of the light scattering statistics in a well characterized tissue-like particulate medium using optical coherence tomography (OCT). It is shown that for low scatterer density, the governing statistics depart considerably from a Gaussian description and follow the K distribution for both OCT amplitude and intensity. The PDF formalism is shown to be independent of the scatterer flow conditions; this is expected from theory, and suggests robustness and motion independence of the OCT amplitude (and OCT intensity) PDF metrics in the context of potential biomedical applications.

  8. Probability density function formalism for optical coherence tomography signal analysis: a controlled phantom study.

    PubMed

    Weatherbee, Andrew; Sugita, Mitsuro; Bizheva, Kostadinka; Popov, Ivan; Vitkin, Alex

    2016-06-15

    The distribution of backscattered intensities as described by the probability density function (PDF) of tissue-scattered light contains information that may be useful for tissue assessment and diagnosis, including characterization of its pathology. In this Letter, we examine the PDF description of the light scattering statistics in a well characterized tissue-like particulate medium using optical coherence tomography (OCT). It is shown that for low scatterer density, the governing statistics depart considerably from a Gaussian description and follow the K distribution for both OCT amplitude and intensity. The PDF formalism is shown to be independent of the scatterer flow conditions; this is expected from theory, and suggests robustness and motion independence of the OCT amplitude (and OCT intensity) PDF metrics in the context of potential biomedical applications. PMID:27304274

  9. Description of a new technique for repairing chronic type B dissections that involve visceral branches being fed by both true and false lumen by using both lumens as conduits

    PubMed Central

    Anderson, Joe; Remund, Tyler; Pohlson, Katie

    2016-01-01

    Here we present three cases performed using a novel technique where aortic flow is compartmentalized proximal to the target vessels through a physician-modified endograft. The visceral segment is then further compartmentalized by the use of another physician modified endograft. By compartmentalizing the flow proximal to the visceral segment, both the true lumen and false lumen can be used as conduits for coextensive bridging stent grafts. Overall, patients have tolerated this procedure extremely well, and while further study and follow-up must be conducted, this procedure could offer a reasonable long-term solution to thoracoabdominal aortic aneurysms complicated by dissection. PMID:25972031

  10. Description of a new technique for repairing chronic type B dissections that involve visceral branches being fed by both true and false lumen by using both lumens as conduits.

    PubMed

    Anderson, Joe; Remund, Tyler; Pohlson, Katie; Kelly, Patrick

    2016-02-01

    Here we present three cases performed using a novel technique where aortic flow is compartmentalized proximal to the target vessels through a physician-modified endograft. The visceral segment is then further compartmentalized by the use of another physician modified endograft. By compartmentalizing the flow proximal to the visceral segment, both the true lumen and false lumen can be used as conduits for coextensive bridging stent grafts. Overall, patients have tolerated this procedure extremely well, and while further study and follow-up must be conducted, this procedure could offer a reasonable long-term solution to thoracoabdominal aortic aneurysms complicated by dissection.

  11. Systolic temporal arithmetic; A new formalism for specification and verification of systolic arrays

    SciTech Connect

    Ling, N. ); Bayoumi, M.A. )

    1990-08-01

    This paper introduces a novel formalism named systolic temporal arithmetic (STA) suitable for describing arithmetic operations in dynamic environments. The motivation behind the development of STA is to use it for formal specifications and verifications of systolic arrays at the array architecture level. Besides providing value and operation abstraction from the lower level, it also exploits several features of systolic arrays such as synchrony, regularity, repeatability, modularity, pipelinability, parallel processing ability, as well as spatial and temporal locality. STA provides constructs and verification techniques for simple, efficient, and effective systolic array specification and verification. Verification techniques such as mathematical induction are suggested to exploit these systolic array features so as to speedup the process.

  12. Issues to be considered on obtaining plant models for formal verification purposes

    NASA Astrophysics Data System (ADS)

    Pacheco, R.; Gonzalez, L.; Intriago, M.; Machado, J.; Prisacaru, G.; Olaru, D.

    2016-08-01

    The development of dependable software for mechatronic systems can be a very complex and hard task. For facilitating the obtaining of dependable software for industrial controllers, some powerful software tools and analysis techniques can be used. Mainly, when using simulation and formal verification analysis techniques, it is necessary to develop plant models, in order to describe the plant behavior of those systems. However, developing a plant model implies that designer takes his (or her) decisions concerning granularity and level of abstraction of models; approach to consider for modeling (global or modular); and definition of strategies for simulation and formal verification tasks. This paper intends to highlight some aspects that can be considered for taking into account those decisions. For this purpose, it is presented a case study and there are illustrated and discussed very important aspects concerning above exposed issues.

  13. Full-body gestures and movements recognition: user descriptive and unsupervised learning approaches in GDL classifier

    NASA Astrophysics Data System (ADS)

    Hachaj, Tomasz; Ogiela, Marek R.

    2014-09-01

    Gesture Description Language (GDL) is a classifier that enables syntactic description and real time recognition of full-body gestures and movements. Gestures are described in dedicated computer language named Gesture Description Language script (GDLs). In this paper we will introduce new GDLs formalisms that enable recognition of selected classes of movement trajectories. The second novelty is new unsupervised learning method with which it is possible to automatically generate GDLs descriptions. We have initially evaluated both proposed extensions of GDL and we have obtained very promising results. Both the novel methodology and evaluation results will be described in this paper.

  14. Nondestructive evaluation technique guide

    NASA Technical Reports Server (NTRS)

    Vary, A.

    1973-01-01

    A total of 70 individual nondestructive evaluation (NDE) techniques are described. Information is presented that permits ease of comparison of the merits and limitations of each technique with respect to various NDE problems. An NDE technique classification system is presented. It is based on the system that was adopted by the National Materials Advisory Board (NMAB). The classification system presented follows the NMAB system closely with the exception of additional categories that have been added to cover more advanced techniques presently in use. The rationale of the technique is explained. The format provides for a concise description of each technique, the physical principles involved, objectives of interrogation, example applications, limitations of each technique, a schematic illustration, and key reference material. Cross-index tabulations are also provided so that particular NDE problems can be referred to appropriate techniques.

  15. Teaching Descriptive Style.

    ERIC Educational Resources Information Center

    Brashers, H. C.

    1968-01-01

    As the inexperienced writer becomes aware of the issues involved in the composition of effective descriptive prose, he also develops a consistent control over his materials. The persona he chooses, if coherently thought out, can function as an index of many choices, helping him to manipulate the tone, intent, and mood of this style; to regulate…

  16. Interpreter composition issues in the formal verification of a processor-memory module

    NASA Technical Reports Server (NTRS)

    Fura, David A.; Cohen, Gerald C.

    1994-01-01

    This report describes interpreter composition techniques suitable for the formal specification and verification of a processor-memory module using the HOL theorem proving system. The processor-memory module is a multichip subsystem within a fault-tolerant embedded system under development within the Boeing Defense and Space Group. Modeling and verification methods were developed that permit provably secure composition at the transaction-level of specification, significantly reducing the complexity of the hierarchical verification of the system.

  17. Coincidence and covariance data acquisition in photoelectron and -ion spectroscopy. I. Formal theory

    NASA Astrophysics Data System (ADS)

    Mikosch, Jochen; Patchkovskii, Serguei

    2013-10-01

    We derive a formal theory of noisy Poisson processes with multiple outcomes. We obtain simple, compact expressions for the probability distribution function of arbitrarily complex composite events and its moments. We illustrate the utility of the theory by analyzing properties of coincidence and covariance photoelectron-photoion detection involving single-ionization events. The results and techniques introduced in this work are directly applicable to more general coincidence and covariance experiments, including multiple ionization and multiple-ion fragmentation pathways.

  18. Formal education and back pain: a review

    PubMed Central

    Dionne, C; Von Korff, M; Koepsell, T; Deyo, R; Barlow, W; Checkoway, H

    2001-01-01

    OBJECTIVES—To summarise the scientific evidence on the relation between educational status and measures of the frequency and the consequences of back pain and of the outcomes of interventions among back pain patients, and to outline possible mechanisms that could explain such an association if found.
DESIGN—Sixty four articles published between 1966 and 2000 that documented the association of formal education with back pain were reviewed.
MAIN RESULTS—Overall, the current available evidence points indirectly to a stronger association of low education with longer duration and/or higher recurrence of back pain than to an association with onset. The many reports of an association of low education with adverse consequences of back pain also suggest that the course of a back pain episode is less favourable among persons with low educational attainment. Mechanisms that could explain these associations include variations in behavioural and environmental risk factors by educational status, differences in occupational factors, compromised "health stock" among people with low education, differences in access to and utilisation of health services, and adaptation to stress. Although lower education was not associated with the outcomes of interventions in major studies, it is difficult, in light of the current limited available evidence, to draw firm conclusions on this association.
CONCLUSION—Scientific evidence supports the hypothesis that less well educated people are more likely to be affected by disabling back pain. Further study of this association may help advance our understanding of back pain as well as understanding of the relation between socioeconomic status and disease as a general phenomenon.


Keywords: back pain; educational status PMID:11413174

  19. A formal model of interpersonal inference

    PubMed Central

    Moutoussis, Michael; Trujillo-Barreto, Nelson J.; El-Deredy, Wael; Dolan, Raymond J.; Friston, Karl J.

    2014-01-01

    Introduction: We propose that active Bayesian inference—a general framework for decision-making—can equally be applied to interpersonal exchanges. Social cognition, however, entails special challenges. We address these challenges through a novel formulation of a formal model and demonstrate its psychological significance. Method: We review relevant literature, especially with regards to interpersonal representations, formulate a mathematical model and present a simulation study. The model accommodates normative models from utility theory and places them within the broader setting of Bayesian inference. Crucially, we endow people's prior beliefs, into which utilities are absorbed, with preferences of self and others. The simulation illustrates the model's dynamics and furnishes elementary predictions of the theory. Results: (1) Because beliefs about self and others inform both the desirability and plausibility of outcomes, in this framework interpersonal representations become beliefs that have to be actively inferred. This inference, akin to “mentalizing” in the psychological literature, is based upon the outcomes of interpersonal exchanges. (2) We show how some well-known social-psychological phenomena (e.g., self-serving biases) can be explained in terms of active interpersonal inference. (3) Mentalizing naturally entails Bayesian updating of how people value social outcomes. Crucially this includes inference about one's own qualities and preferences. Conclusion: We inaugurate a Bayes optimal framework for modeling intersubject variability in mentalizing during interpersonal exchanges. Here, interpersonal representations are endowed with explicit functional and affective properties. We suggest the active inference framework lends itself to the study of psychiatric conditions where mentalizing is distorted. PMID:24723872

  20. Ultrasound-guided percutaneous neuroplasty of the lateral femoral cutaneous nerve for the treatment of meralgia paresthetica: a case report and description of a new ultrasound-guided technique.

    PubMed

    Mulvaney, Sean W

    2011-01-01

    The lateral femoral cutaneous nerve (LFCN) can be visualized with ultrasound imaging using a high frequency linear transducer. The entrapment of the LFCN, often near the lateral aspect of the inguinal ligament, is accepted as an etiology of meralgia paresthetica (MP). This case report describes an ultrasound-guided, percutaneous technique that utilizes injected fluid to facilitate blunt dissection (or hydrodissection) to perform an external neuroplasty of the LFCN. This procedure resulted in immediate, long-term relief of pain associated with severe, chronic MP. This procedure may potentially represent an alternate treatment for patients with contraindications or partial contraindications to surgical neurolysis, nerve transection (usually described as being performed under general anesthesia), or corticosteroid injection, or in patients not responding to conservative treatment measures.

  1. Using Ontologies to Formalize Services Specifications in Multi-Agent Systems

    NASA Technical Reports Server (NTRS)

    Breitman, Karin Koogan; Filho, Aluizio Haendchen; Haeusler, Edward Hermann

    2004-01-01

    One key issue in multi-agent systems (MAS) is their ability to interact and exchange information autonomously across applications. To secure agent interoperability, designers must rely on a communication protocol that allows software agents to exchange meaningful information. In this paper we propose using ontologies as such communication protocol. Ontologies capture the semantics of the operations and services provided by agents, allowing interoperability and information exchange in a MAS. Ontologies are a formal, machine processable, representation that allows to capture the semantics of a domain and, to derive meaningful information by way of logical inference. In our proposal we use a formal knowledge representation language (OWL) that translates into Description Logics (a subset of first order logic), thus eliminating ambiguities and providing a solid base for machine based inference. The main contribution of this approach is to make the requirements explicit, centralize the specification in a single document (the ontology itself), at the same that it provides a formal, unambiguous representation that can be processed by automated inference machines.

  2. Developing Musicality: Formal and Informal Practices

    ERIC Educational Resources Information Center

    Jaffurs, Sheri E.

    2004-01-01

    Musicality is a loosely used term with many meanings. It can be applied to a small child who chants a nursery rhyme, or to a harmonica player who plays by ear, or to a conductor like Toscanini. Some educators and philosophers believe that musicality is manifested in the technical achievements of musicians. Others believe that technique is…

  3. Soliton scattering in the Darboux transformation formalism

    SciTech Connect

    Matveev, V.B.; Sall', M.A.

    1987-05-20

    The Darboux transformation technique is applied to derive soliton scattering formulas for the Kadomtsev-Petviashvili equation, the KdV equation, the nonlocal KdV equation, the two-dimensionalized Toda chain and its periodic reductions, in particular the sine-Gordon equation.

  4. On the description of nonunitary neutrino mixing

    NASA Astrophysics Data System (ADS)

    Escrihuela, F. J.; Forero, D. V.; Miranda, O. G.; Tórtola, M.; Valle, J. W. F.

    2015-09-01

    Neutrino oscillations are well established and the relevant parameters determined with good precision, except for the C P phase, in terms of a unitary lepton mixing matrix. Seesaw extensions of the Standard Model predict unitarity deviations due to the admixture of heavy isosinglet neutrinos. We provide a complete description of the unitarity and universality deviations in the light-neutrino sector. Neutrino oscillation experiments involving electron or muon neutrinos and antineutrinos are fully described in terms of just three new real parameters and a new C P phase, in addition to the ones describing oscillations with unitary mixing. Using this formalism we describe the implications of nonunitarity for neutrino oscillations and summarize the model-independent constraints on heavy-neutrino couplings that arise from current experiments.

  5. Formalizing structured file services for the data storage and retrieval subsystem of the data management system for Spacestation Freedom

    NASA Technical Reports Server (NTRS)

    Jamsek, Damir A.

    1993-01-01

    A brief example of the use of formal methods techniques in the specification of a software system is presented. The report is part of a larger effort targeted at defining a formal methods pilot project for NASA. One possible application domain that may be used to demonstrate the effective use of formal methods techniques within the NASA environment is presented. It is not intended to provide a tutorial on either formal methods techniques or the application being addressed. It should, however, provide an indication that the application being considered is suitable for a formal methods by showing how such a task may be started. The particular system being addressed is the Structured File Services (SFS), which is a part of the Data Storage and Retrieval Subsystem (DSAR), which in turn is part of the Data Management System (DMS) onboard Spacestation Freedom. This is a software system that is currently under development for NASA. An informal mathematical development is presented. Section 3 contains the same development using Penelope (23), an Ada specification and verification system. The complete text of the English version Software Requirements Specification (SRS) is reproduced in Appendix A.

  6. Description scheme for video editing work

    NASA Astrophysics Data System (ADS)

    Ruiloba, Rosa I.; Joly, Philippe

    2001-03-01

    This article presents a Description Scheme (DS) to describe the audio-visual documents from the video editing work point of view. This DS is based on edition techniques used in the video edition domain. The main objective of this DS is to provide a complete, modular and extensible description of the structure of the video documents based on editing process. This VideoEditing DS is generic in the sense that it may be used in a large number of applications such as video document indexing and analysis, description of Edit Decision List and elaboration of editing patterns. It is based on accurate and complete definitions of shots and transition effects required for video document analysis applications. The VideoEditing DS allows three levels of description : analytic, synthetic and semantic. In the DS, the higher (resp. the lower) is the element of description, the more analytic (resp. synthetic) is the information. %Phil This DS allows describing the editing work made by editing boards, using more detailed descriptors of Shots and Transition DSs. These elements are provided to define editing patterns that allow several possible reconstructions of movies depending on, for example, the target audience. A part of the video description made with this DS may be automatically produced by the video to shots segmentation algorithms (analytic DSs ) or by editing software, at the same time the edition work is made. This DS gives an answer to the needs related to the exchange of editing work descriptions between editing softwares. At the same time, the same DS provide an analytic description of editing work which is complementary to existing standards for Edit Decision Lists like SMPTE or AAF.

  7. Microprocessor Simulation: A Training Technique.

    ERIC Educational Resources Information Center

    Oscarson, David J.

    1982-01-01

    Describes the design and application of a microprocessor simulation using BASIC for formal training of technicians and managers and as a management tool. Illustrates the utility of the modular approach for the instruction and practice of decision-making techniques. (SK)

  8. Environmental Education in the Formal Sector of Education in Uganda.

    ERIC Educational Resources Information Center

    Mucunguzi, P.

    1995-01-01

    Provides a critical review of the present state of environmental education in the formal sector of education in Uganda. Recommends an improved approach to formal environmental education based on a multidisciplinary foundation that embraces the biophysical environment, people, culture, politics, and socioeconomic systems. (LZ)

  9. I, Pronoun: A Study of Formality in Online Content

    ERIC Educational Resources Information Center

    Thayer, Alexander; Evans, Mary B.; McBride, Alicia A.; Queen, Matt; Spyridakis, Jan H.

    2010-01-01

    This article presents the results of a study that investigated readers' perceptions of tone formality in online text passages. The study found that readers perceived text passages to be less formal when they contained personal pronouns, active voice verbs, informal punctuation, or verb contractions. The study reveals that professional…

  10. Integrating Formal and Grounded Representations in Combinatorics Learning

    ERIC Educational Resources Information Center

    Braithwaite, David W.; Goldstone, Robert L.

    2013-01-01

    The terms "concreteness fading" and "progressive formalization" have been used to describe instructional approaches to science and mathematics that use grounded representations to introduce concepts and later transition to more formal representations of the same concepts. There are both theoretical and empirical reasons to…

  11. 47 CFR 8.14 - General formal complaint procedures.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false General formal complaint procedures. 8.14 Section 8.14 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRESERVING THE OPEN INTERNET § 8.14 General formal complaint procedures. (a) Complaints. In addition to the general...

  12. 47 CFR 8.14 - General formal complaint procedures.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false General formal complaint procedures. 8.14 Section 8.14 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRESERVING THE OPEN INTERNET § 8.14 General formal complaint procedures. (a) Complaints. In addition to the general...

  13. 47 CFR 8.14 - General formal complaint procedures.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false General formal complaint procedures. 8.14 Section 8.14 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRESERVING THE OPEN INTERNET § 8.14 General formal complaint procedures. (a) Complaints. In addition to the general...

  14. 47 CFR 8.14 - General formal complaint procedures.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false General formal complaint procedures. 8.14 Section 8.14 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRESERVING THE OPEN INTERNET § 8.14 General formal complaint procedures. (a) Complaints. In addition to the general...

  15. Financing Adult and Non-Formal Education in Nigeria

    ERIC Educational Resources Information Center

    Hassan, Moshood Ayinde

    2009-01-01

    The purpose of this study is to determine how adult and non formal education is financed in Nigeria; and to examine areas or forms of and the problems of financing adult and non-formal education in Nigeria. Survey research was used in order to carry out the study. Three hundred and twenty five (325) respondents from government agencies,…

  16. Toward the Characterization of Non-Formal Pedagogy.

    ERIC Educational Resources Information Center

    Silberman-Keller, Diana

    This study examined characteristic attributes of non-formal education and the non-formal pedagogy directing its teaching and learning processes. Data were collected on organizational and pedagogical characteristics in several out-of-school organizations (youth movements, youth organizations, community centers, bypass educational systems, local…

  17. Academic Achievement and Formal Thought in Engineering Students

    ERIC Educational Resources Information Center

    Vazquez, Stella Maris; de Anglat, Hilda Difabio

    2009-01-01

    Introduction: Research on university-level academic performance has significantly linked failure and dropping out to formal reasoning deficiency. We have not found any papers on formal thought in Argentine university students, in spite of the obvious shortcomings observed in the classrooms. Thus, the main objective of this paper was exploring the…

  18. How Online Journalists Learn within a Non-Formal Context

    ERIC Educational Resources Information Center

    Kronstad, Morten; Eide, Martin

    2015-01-01

    Purpose: The purpose of this paper is to contribute to the understanding of workplace learning, with a focus on the non-formal learning that takes place among online journalists. The focus of this article is journalists working in an online newspaper and their experiences with workplace and non-formal learning, centering on framework conditions…

  19. Beyond Formalism: Literary Criticism Now and in the Immediate Future.

    ERIC Educational Resources Information Center

    Standley, Fred L.

    Formalism, an amalgamation of literary critical methods originating in the 1920's, which emphasize close textual analysis of the literary work itself, is declining as the predominant critical approach due to its self-imposed limitations. New perspectives, attempting to counter the fragmentation of formalism and demonstrating an awareness of the…

  20. A Construction and Validation of Formal Operational Reasoning Instruments.

    ERIC Educational Resources Information Center

    Bart, William M.

    In Piaget's developmental psychology the fourth and highest stage of human cognitive development is that of formal operations. The research on formal thought instruments is outlined. This study was designed to construct and validate paper-and-pencil instruments which could be used to select students capable of abstract conceptualization,…

  1. Recognising Non-Formal and Informal Learning: An Open Challenge

    ERIC Educational Resources Information Center

    Perulli, Elisabetta

    2009-01-01

    The social-institutional endorsement towards the perspective of recognising and enhancing learning acquired outside the formal education and training contexts (non-formal and informal learning), has been gaining strength and has entered policy agendas throughout Europe, but also in other major non-European countries. Nevertheless there are still…

  2. 21 CFR 1404.835 - Are debarment proceedings formal?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Are debarment proceedings formal? 1404.835 Section 1404.835 Food and Drugs OFFICE OF NATIONAL DRUG CONTROL POLICY GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Debarment § 1404.835 Are debarment proceedings formal? (a) Debarment proceedings are conducted...

  3. 21 CFR 1404.740 - Are suspension proceedings formal?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Are suspension proceedings formal? 1404.740 Section 1404.740 Food and Drugs OFFICE OF NATIONAL DRUG CONTROL POLICY GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Suspension § 1404.740 Are suspension proceedings formal? (a)...

  4. Formal Education, Eminence, and Dogmatism: The Curvilinear Relationship.

    ERIC Educational Resources Information Center

    Simonton, Dean Keith

    The relationship between formal education and creativity was investigated in two studies. A reanalysis of Cox's (1926) 301 geniuses indicated that achieved eminence of creators is a curvilinear inverted-U function of formal education. Secondly, a study of 33 American presidents found that dogmatism (i.e., idealistic inflexibility) is a curvilinear…

  5. Toward a mathematical formalism of performance, task difficulty, and activation

    NASA Technical Reports Server (NTRS)

    Samaras, George M.

    1988-01-01

    The rudiments of a mathematical formalism for handling operational, physiological, and psychological concepts are developed for use by the man-machine system design engineer. The formalism provides a framework for developing a structured, systematic approach to the interface design problem, using existing mathematical tools, and simplifying the problem of telling a machine how to measure and use performance.

  6. 13 CFR 301.10 - Formal application requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Formal application requirements. 301.10 Section 301.10 Business Credit and Assistance ECONOMIC DEVELOPMENT ADMINISTRATION, DEPARTMENT... Projects selected from successful proposals, EDA will invite the proponents to submit a formal...

  7. Blending Formal and Informal Learning Networks for Online Learning

    ERIC Educational Resources Information Center

    Czerkawski, Betül C.

    2016-01-01

    With the emergence of social software and the advance of web-based technologies, online learning networks provide invaluable opportunities for learning, whether formal or informal. Unlike top-down, instructor-centered, and carefully planned formal learning settings, informal learning networks offer more bottom-up, student-centered participatory…

  8. Enhancing Formal E-Learning with Edutainment on Social Networks

    ERIC Educational Resources Information Center

    Labus, A.; Despotovic-Zrakic, M.; Radenkovic, B.; Bogdanovic, Z.; Radenkovic, M.

    2015-01-01

    This paper reports on the investigation of the possibilities of enhancing the formal e-learning process by harnessing the potential of informal game-based learning on social networks. The goal of the research is to improve the outcomes of the formal learning process through the design and implementation of an educational game on a social network…

  9. On the Equivalence of Formal Grammars and Machines.

    ERIC Educational Resources Information Center

    Lund, Bruce

    1991-01-01

    Explores concepts of formal language and automata theory underlying computational linguistics. A computational formalism is described known as a "logic grammar," with which computational systems process linguistic data, with examples in declarative and procedural semantics and definite clause grammars. (13 references) (CB)

  10. Adolescent Egocentrism and Formal Operations: Tests of a Theoretical Assumption.

    ERIC Educational Resources Information Center

    Lapsley, David K.; And Others

    1986-01-01

    Describes two studies of the theoretical relation between adolescent egocentrism and formal operations. Study 1 used the Adolescent Egocentrism Scale (AES) and Lunzer's battery of formal reasoning tasks to assess 183 adolescents. Study 2 administered the AES, the Imaginary Audience Scale (IAS), and the Test of Logical Thinking to 138 adolescents.…

  11. Formal Verification of a Conflict Resolution and Recovery Algorithm

    NASA Technical Reports Server (NTRS)

    Maddalon, Jeffrey; Butler, Ricky; Geser, Alfons; Munoz, Cesar

    2004-01-01

    New air traffic management concepts distribute the duty of traffic separation among system participants. As a consequence, these concepts have a greater dependency and rely heavily on on-board software and hardware systems. One example of a new on-board capability in a distributed air traffic management system is air traffic conflict detection and resolution (CD&R). Traditional methods for safety assessment such as human-in-the-loop simulations, testing, and flight experiments may not be sufficient for this highly distributed system as the set of possible scenarios is too large to have a reasonable coverage. This paper proposes a new method for the safety assessment of avionics systems that makes use of formal methods to drive the development of critical systems. As a case study of this approach, the mechanical veri.cation of an algorithm for air traffic conflict resolution and recovery called RR3D is presented. The RR3D algorithm uses a geometric optimization technique to provide a choice of resolution and recovery maneuvers. If the aircraft adheres to these maneuvers, they will bring the aircraft out of conflict and the aircraft will follow a conflict-free path to its original destination. Veri.cation of RR3D is carried out using the Prototype Verification System (PVS).

  12. Quantum optimal control theory in the linear response formalism

    SciTech Connect

    Castro, Alberto; Tokatly, I. V.

    2011-09-15

    Quantum optimal control theory (QOCT) aims at finding an external field that drives a quantum system in such a way that optimally achieves some predefined target. In practice, this normally means optimizing the value of some observable, a so-called merit function. In consequence, a key part of the theory is a set of equations, which provides the gradient of the merit function with respect to parameters that control the shape of the driving field. We show that these equations can be straightforwardly derived using the standard linear response theory, only requiring a minor generalization: the unperturbed Hamiltonian is allowed to be time dependent. As a result, the aforementioned gradients are identified with certain response functions. This identification leads to a natural reformulation of QOCT in terms of the Keldysh contour formalism of the quantum many-body theory. In particular, the gradients of the merit function can be calculated using the diagrammatic technique for nonequilibrium Green's functions, which should be helpful in the application of QOCT to computationally difficult many-electron problems.

  13. Towards the exploitation of formal methods for information fusion

    NASA Astrophysics Data System (ADS)

    Clemens, Joachim; Wille, Robert; Schill, Kerstin

    2016-05-01

    When an autonomous system has to act in or interact with an environment, a suitable representation of it is required. In the past decades, many different representation forms - especially spacial ones - have been proposed and even more information fusion techniques were developed in order to build these representations from multiple information sources. However, most of these algorithms do not exploit the full potential of the available information. This is caused by the fact that they are not able to handle the full complexity of all possible solutions compatible with the information and that they rely on restrictive assumptions (i.e. independencies) in order to make the computation feasible. In this work, a new methodology is envisioned that utilizes formal methods, in particular solvers for Pseudo-Boolean Optimization, to drop some of these assumptions. In order to illustrate the ideas, information fusion based on belief functions and occupancy grid maps are considered. It is shown that this approach allows for considering dependencies among multiple cells and thus significantly reduces the uncertainty in the resulting representation.

  14. On the simulation of indistinguishable fermions in the many-body Wigner formalism

    SciTech Connect

    Sellier, J.M. Dimov, I.

    2015-01-01

    The simulation of quantum systems consisting of interacting, indistinguishable fermions is an incredible mathematical problem which poses formidable numerical challenges. Many sophisticated methods addressing this problem are available which are based on the many-body Schrödinger formalism. Recently a Monte Carlo technique for the resolution of the many-body Wigner equation has been introduced and successfully applied to the simulation of distinguishable, spinless particles. This numerical approach presents several advantages over other methods. Indeed, it is based on an intuitive formalism in which quantum systems are described in terms of a quasi-distribution function, and highly scalable due to its Monte Carlo nature. In this work, we extend the many-body Wigner Monte Carlo method to the simulation of indistinguishable fermions. To this end, we first show how fermions are incorporated into the Wigner formalism. Then we demonstrate that the Pauli exclusion principle is intrinsic to the formalism. As a matter of fact, a numerical simulation of two strongly interacting fermions (electrons) is performed which clearly shows the appearance of a Fermi (or exchange–correlation) hole in the phase-space, a clear signature of the presence of the Pauli principle. To conclude, we simulate 4, 8 and 16 non-interacting fermions, isolated in a closed box, and show that, as the number of fermions increases, we gradually recover the Fermi–Dirac statistics, a clear proof of the reliability of our proposed method for the treatment of indistinguishable particles.

  15. On the formalization and reuse of scientific research.

    PubMed

    King, Ross D; Liakata, Maria; Lu, Chuan; Oliver, Stephen G; Soldatova, Larisa N

    2011-10-01

    The reuse of scientific knowledge obtained from one investigation in another investigation is basic to the advance of science. Scientific investigations should therefore be recorded in ways that promote the reuse of the knowledge they generate. The use of logical formalisms to describe scientific knowledge has potential advantages in facilitating such reuse. Here, we propose a formal framework for using logical formalisms to promote reuse. We demonstrate the utility of this framework by using it in a worked example from biology: demonstrating cycles of investigation formalization [F] and reuse [R] to generate new knowledge. We first used logic to formally describe a Robot scientist investigation into yeast (Saccharomyces cerevisiae) functional genomics [f(1)]. With Robot scientists, unlike human scientists, the production of comprehensive metadata about their investigations is a natural by-product of the way they work. We then demonstrated how this formalism enabled the reuse of the research in investigating yeast phenotypes [r(1) = R(f(1))]. This investigation found that the removal of non-essential enzymes generally resulted in enhanced growth. The phenotype investigation was then formally described using the same logical formalism as the functional genomics investigation [f(2) = F(r(1))]. We then demonstrated how this formalism enabled the reuse of the phenotype investigation to investigate yeast systems-biology modelling [r(2) = R(f(2))]. This investigation found that yeast flux-balance analysis models fail to predict the observed changes in growth. Finally, the systems biology investigation was formalized for reuse in future investigations [f(3) = F(r(2))]. These cycles of reuse are a model for the general reuse of scientific knowledge. PMID:21490004

  16. On the formalization and reuse of scientific research

    PubMed Central

    King, Ross D.; Liakata, Maria; Lu, Chuan; Oliver, Stephen G.; Soldatova, Larisa N.

    2011-01-01

    The reuse of scientific knowledge obtained from one investigation in another investigation is basic to the advance of science. Scientific investigations should therefore be recorded in ways that promote the reuse of the knowledge they generate. The use of logical formalisms to describe scientific knowledge has potential advantages in facilitating such reuse. Here, we propose a formal framework for using logical formalisms to promote reuse. We demonstrate the utility of this framework by using it in a worked example from biology: demonstrating cycles of investigation formalization [F] and reuse [R] to generate new knowledge. We first used logic to formally describe a Robot scientist investigation into yeast (Saccharomyces cerevisiae) functional genomics [f1]. With Robot scientists, unlike human scientists, the production of comprehensive metadata about their investigations is a natural by-product of the way they work. We then demonstrated how this formalism enabled the reuse of the research in investigating yeast phenotypes [r1 = R(f1)]. This investigation found that the removal of non-essential enzymes generally resulted in enhanced growth. The phenotype investigation was then formally described using the same logical formalism as the functional genomics investigation [f2 = F(r1)]. We then demonstrated how this formalism enabled the reuse of the phenotype investigation to investigate yeast systems-biology modelling [r2 = R(f2)]. This investigation found that yeast flux-balance analysis models fail to predict the observed changes in growth. Finally, the systems biology investigation was formalized for reuse in future investigations [f3 = F(r2)]. These cycles of reuse are a model for the general reuse of scientific knowledge. PMID:21490004

  17. Annotation of rule-based models with formal semantics to enable creation, analysis, reuse and visualization

    PubMed Central

    Misirli, Goksel; Cavaliere, Matteo; Waites, William; Pocock, Matthew; Madsen, Curtis; Gilfellon, Owen; Honorato-Zimmer, Ricardo; Zuliani, Paolo; Danos, Vincent; Wipat, Anil

    2016-01-01

    Motivation: Biological systems are complex and challenging to model and therefore model reuse is highly desirable. To promote model reuse, models should include both information about the specifics of simulations and the underlying biology in the form of metadata. The availability of computationally tractable metadata is especially important for the effective automated interpretation and processing of models. Metadata are typically represented as machine-readable annotations which enhance programmatic access to information about models. Rule-based languages have emerged as a modelling framework to represent the complexity of biological systems. Annotation approaches have been widely used for reaction-based formalisms such as SBML. However, rule-based languages still lack a rich annotation framework to add semantic information, such as machine-readable descriptions, to the components of a model. Results: We present an annotation framework and guidelines for annotating rule-based models, encoded in the commonly used Kappa and BioNetGen languages. We adapt widely adopted annotation approaches to rule-based models. We initially propose a syntax to store machine-readable annotations and describe a mapping between rule-based modelling entities, such as agents and rules, and their annotations. We then describe an ontology to both annotate these models and capture the information contained therein, and demonstrate annotating these models using examples. Finally, we present a proof of concept tool for extracting annotations from a model that can be queried and analyzed in a uniform way. The uniform representation of the annotations can be used to facilitate the creation, analysis, reuse and visualization of rule-based models. Although examples are given, using specific implementations the proposed techniques can be applied to rule-based models in general. Availability and implementation: The annotation ontology for rule-based models can be found at http

  18. Spacelab J experiment descriptions

    SciTech Connect

    Miller, T.Y.

    1993-08-01

    Brief descriptions of the experiment investigations for the Spacelab J Mission which was launched from the Kennedy Space Center aboard the Endeavour in Sept. 1992 are presented. Experiments cover the following: semiconductor crystals; single crystals; superconducting composite materials; crystal growth; bubble behavior in weightlessness; microgravity environment; health monitoring of Payload Specialists; cultured plant cells; effect of low gravity on calcium metabolism and bone formation; and circadian rhythm. Separate abstracts have been prepared for articles from this report.

  19. Spacelab J experiment descriptions

    NASA Technical Reports Server (NTRS)

    Miller, Teresa Y. (Editor)

    1993-01-01

    Brief descriptions of the experiment investigations for the Spacelab J Mission which was launched from the Kennedy Space Center aboard the Endeavour in Sept. 1992 are presented. Experiments cover the following: semiconductor crystals; single crystals; superconducting composite materials; crystal growth; bubble behavior in weightlessness; microgravity environment; health monitoring of Payload Specialists; cultured plant cells; effect of low gravity on calcium metabolism and bone formation; and circadian rhythm.

  20. Formal, Non-Formal and Informal learning: The Case of Literacy, Essential Skills, and Language Learning in Canada

    ERIC Educational Resources Information Center

    Eaton, Sarah Elaine

    2010-01-01

    This research report investigates the links between formal, non-formal and informal learning and the differences between them. In particular, the report aims to link these notions of learning to literacy and essential skills, as well as the learning of second and other languages in Canada. It builds upon the work of the OECD (n.d.) and Werquin…

  1. Formal care providers' perceptions of home- and community-based services: informing dementia care quality.

    PubMed

    Jansen, Lynn; Forbes, Dorothy A; Markle-Reid, Maureen; Hawranik, Pamela; Kingston, Dawn; Peacock, Shellie; Henderson, Sandra; Leipert, Beverly

    2009-01-01

    Little attention has been given to the perceptions of formal care providers on the nature and quality of home- and community-based dementia care. The purpose of this descriptive interpretive research was to explore formal care providers' perceptions of their experiences with Canadian home- and community-based dementia care. Participants within three personal interviews and six focus groups (n = 41) included nurses, social workers, therapists, home care aides, and Alzheimer Society personnel (front line/management) in rural and urban areas of Saskatchewan (n = 16), Manitoba (n = 20), and Ontario (n = 8). Two overarching thematic categories, Service Availability and Service Acceptability, emerged from the data analysis. Subthemes of availability were identified as: (a) challenges of service availability, including service wait lists, lack of home care provider training, lack of community-based dementia care infrastructure, and sociocultural and geographic barriers to accessing dementia services; and (b) essential facilitators of availability, including service infrastructure, service bridging, and agency partnerships to form coordinated care systems. Subthemes of acceptability were revealed as: (a) essential components of dementia care, including provision of comprehensive personal care and the use of dementia care professional practice knowledge within a home care setting; and (b) service challenges, including inadequate service time for the physical care and socioemotional support of the client and family caregiver, caregiver and formal provider difficulty with navigation of a fragmented care system, lack of system coordination, and financial costs of services. Essential, integrated dementia care could be established by listening to the "voices of formal care providers," thereby decreasing dementia care costs and increasing the quality of life for those with dementia, and their family caregivers.

  2. Formal semantic specifications as implementation blueprints for real-time programming languages

    NASA Technical Reports Server (NTRS)

    Feyock, S.

    1981-01-01

    Formal definitions of language and system semantics provide highly desirable checks on the correctness of implementations of programming languages and their runtime support systems. If these definitions can give concrete guidance to the implementor, major increases in implementation accuracy and decreases in implementation effort can be achieved. It is shown that of the wide variety of available methods the Hgraph (hypergraph) definitional technique (Pratt, 1975), is best suited to serve as such an implementation blueprint. A discussion and example of the Hgraph technique is presented, as well as an overview of the growing body of implementation experience of real-time languages based on Hgraph semantic definitions.

  3. Formal optimization of hovering performance using free wake lifting surface theory

    NASA Technical Reports Server (NTRS)

    Chung, S. Y.

    1986-01-01

    Free wake techniques for performance prediction and optimization of hovering rotor are discussed. The influence functions due to vortex ring, vortex cylinder, and source or vortex sheets are presented. The vortex core sizes of rotor wake vortices are calculated and their importance is discussed. Lifting body theory for finite thickness body is developed for pressure calculation, and hence performance prediction of hovering rotors. Numerical optimization technique based on free wake lifting line theory is presented and discussed. It is demonstrated that formal optimization can be used with the implicit and nonlinear objective or cost function such as the performance of hovering rotors as used in this report.

  4. The limits on combining recursive horn rules with description logics

    SciTech Connect

    Levy, A.Y.; Rousset, M.C.

    1996-12-31

    Horn rule languages have formed the basis for many Artificial Intelligence application languages, but are not expressive enough to model domains with a rich hierarchical structure. Description logics have been designed especially to model rich hierarchies. Several applications would significantly benefit from combining the expressive power of both formalisms. This paper focuses on combining recursive function-free Horn rules with the expressive description logic ALCNR, and shows exactly when a hybrid language with decidable inference can be obtained. First, we show that several of the core constructors of description logics lead by themselves to undecidability of inference when combined with recursive function-free Horn rules. We then show that without these constructors we obtain a maximal subset of ALCNRR that yields a decidable hybrid language. Finally, we describe a restriction on the Horn rules that guarantees decidable inference when combined with all of ALCNR, and covers many of the common usages of recursive rules.

  5. On the description of subsystems in relativistic hypersurface Bohmian mechanics.

    PubMed

    Dürr, Detlef; Lienert, Matthias

    2014-09-01

    A candidate for a realistic relativistic quantum theory is the hypersurface Bohm-Dirac model. Its formulation uses a foliation of space-time into space-like hypersurfaces. In order to apply the theory and to make contact with the usual quantum formalism, one needs a framework for the description of subsystems. The presence of spin together with the foliation renders the subsystem description more complicated than in the non-relativistic case with spin. In this paper, we provide such a framework in terms of an appropriate conditional density matrix and an effective wave function as well as clarify their relation, thereby generalizing previous subsystem descriptions in the non-relativistic case. PMID:25197244

  6. The value of job analysis, job description and performance.

    PubMed

    Wolfe, M N; Coggins, S

    1997-01-01

    All companies, regardless of size, are faced with the same employment concerns. Efficient personnel management requires the use of three human resource techniques--job analysis, job description and performance appraisal. These techniques and tools are not for large practices only. Small groups can obtain the same benefits by employing these performance control measures. Job analysis allows for the development of a compensation system. Job descriptions summarize the most important duties. Performance appraisals help reward outstanding work.

  7. Correlates of formal reasoning: Content and problem effects

    NASA Astrophysics Data System (ADS)

    Linn, Marcia C.; Pulos, Steven; Gans, Adrienne

    Piaget's structural theory of formal thought suggests that a general construct of formal reasoning exists. The content of the task and type of problem employed are often ignored in Piagetian based studies but are important for generalizing findings to other studies and to educational problems. The study reported here examines content and problem effects of formal thought in 13-year-old adolescents. Specifically, three controlling variables tasks with different content and two question type tests (analysis and controlling questions) were administered to 120 seventh graders. Ability measures and personality dimensions associated with formal reasoning in the literature are used to clarify what formal reasoning is and how content and problem type are involved in formal reasoning. Significant main effects were found for problem and content effects (p = 0.001), and a significant interaction was found between the two (p = 0.001). Across the three tasks general ability, field dependency, and locus of control were consistently and significantly related to the controlling questions. However, only measures of field dependency were related to the analysis questions. Combinations of ability and personality factors were found to be uniquely related to each task, within each question type. Results have implications for a theory of formal thought and the teaching of the controlling variables strategy.

  8. What do tests of formal reasoning actually measure?

    NASA Astrophysics Data System (ADS)

    Lawson, Anton E.

    Tests of formal operational reasoning derived from Piagetian theory have been found to be effective predictors of academic achievement. Yet Piaget's theory regarding the underlying nature of formal operations and their employment in specific contexts has run into considerable empirical difficulty. The primary purpose of this study was to present the core of an alternative theory of the nature of advanced scientific reasoning. That theory, referred to as the multiple-hypothesis theory, argues that tests of formal operational reasoning actually measure the extent to which persons have acquired the ability to initiate reasoning with more than one specific antecedent condition, or if they are unable to imagine more than one antecedent condition, they are aware that more than one is possible; therefore conclusions that are drawn are tempered by this possibility. As a test of this multiple-hypothesis theory of advanced reasoning and the contrasting Piagetian theory of formal operations, a sample of 922 college students were first classified as concrete operational, transitional, or formal operational, based upon responses to standard Piagetian measures of formal operational reasoning. They were then administered seven logic tasks. Actual response patterns to the tasks were analyzed and found to be similar to predicted response patterns derived from the multiple-hypothesis theory and were different from those predicted by Piagetian theory. Therefore, support was obtained for the multiple-hypothesis theory. The terms intuitive and reflective were suggested to replace the terms concrete operational and formal operational to refer to persons at varying levels of intellectual development.

  9. A review of research on formal reasoning and science teaching

    NASA Astrophysics Data System (ADS)

    Lawson, Anton E.

    A central purpose of education is to improve students' reasoning abilities. The present review examines research in developmental psychology and science education that has attempted to assess the validity of Piaget's theory of formal thought and its relation to educational practice. Should a central objective of schools be to help students become formal thinkers? To answer this question research has focused on the following subordinate questions: (1) What role does biological maturation play in the development of formal reasoning? (2) Are Piaget's formal tasks reliable and valid? (3) Does formal reasoning constitute a unified and general mode of intellectual functioning? (4) How does the presence or absence of formal reasoning affect school achievement? (5) Can formal reasoning be taught? (6) What is the structural or functional nature of advanced reasoning? The general conclusion drawn is that although Piaget's work and that which has sprung from it leaves a number of unresolved theoretical and methodological problems, it provides an important background from which to make substantial progress toward a most significant educational objective.All our dignity lies in thought. By thought we must elevate ourselves, not by space and time which we can not fill. Let us endeavor then to think well; therein lies the principle of morality. Blaise Pascal 1623-1662.

  10. Proceedings of the Second NASA Formal Methods Symposium

    NASA Technical Reports Server (NTRS)

    Munoz, Cesar (Editor)

    2010-01-01

    This publication contains the proceedings of the Second NASA Formal Methods Symposium sponsored by the National Aeronautics and Space Administration and held in Washington D.C. April 13-15, 2010. Topics covered include: Decision Engines for Software Analysis using Satisfiability Modulo Theories Solvers; Verification and Validation of Flight-Critical Systems; Formal Methods at Intel -- An Overview; Automatic Review of Abstract State Machines by Meta Property Verification; Hardware-independent Proofs of Numerical Programs; Slice-based Formal Specification Measures -- Mapping Coupling and Cohesion Measures to Formal Z; How Formal Methods Impels Discovery: A Short History of an Air Traffic Management Project; A Machine-Checked Proof of A State-Space Construction Algorithm; Automated Assume-Guarantee Reasoning for Omega-Regular Systems and Specifications; Modeling Regular Replacement for String Constraint Solving; Using Integer Clocks to Verify the Timing-Sync Sensor Network Protocol; Can Regulatory Bodies Expect Efficient Help from Formal Methods?; Synthesis of Greedy Algorithms Using Dominance Relations; A New Method for Incremental Testing of Finite State Machines; Verification of Faulty Message Passing Systems with Continuous State Space in PVS; Phase Two Feasibility Study for Software Safety Requirements Analysis Using Model Checking; A Prototype Embedding of Bluespec System Verilog in the PVS Theorem Prover; SimCheck: An Expressive Type System for Simulink; Coverage Metrics for Requirements-Based Testing: Evaluation of Effectiveness; Software Model Checking of ARINC-653 Flight Code with MCP; Evaluation of a Guideline by Formal Modelling of Cruise Control System in Event-B; Formal Verification of Large Software Systems; Symbolic Computation of Strongly Connected Components Using Saturation; Towards the Formal Verification of a Distributed Real-Time Automotive System; Slicing AADL Specifications for Model Checking; Model Checking with Edge-valued Decision Diagrams

  11. Application of a new dosimetry formalism to volumetric modulated arc therapy (VMAT)

    NASA Astrophysics Data System (ADS)

    Rosser, Karen E.; Bedford, James L.

    2009-12-01

    Volumetric modulated arc therapy (VMAT) offers a challenge to classical dosimetry protocols as the beams are dynamic in orientation and aperture shape and may include small apertures. The aim of this paper is to apply a formalism to VMAT beams that has recently been published by the International Atomic Energy Agency (IAEA) working party to improve the dosimetry for small and non-standard fields. We investigated three possible fields and assessed their suitability as plan class specific reference (pcsr) fields. The factors in the new dosimetry formalism were investigated: the conversion of dose to water from the conventional reference field to the pcsr and then from the pcsr to a treatment plan, using a PTW semiflex chamber, two Farmer chambers and an electron diode. Finally, the dose was compared for Alanine, the new formalism and calculated using Pinnacle3 (Philips Radiation Oncology Systems) for two typical clinical VMAT beams. Correction factors between the reference field and the pcsr determined with Alanine range from 0.1% to 2.3% for the three pcsr fields. Dose to water measured using the calibrated ionization chambers is less than 2% different to the dose calculated by Pinnacle3. VMAT planning and delivery procedures have been successfully implemented and a new dosimetry protocol has been investigated for this new technique. Calibration factors for pcsr fields are found to be up to 2.3% different when using the new formalism, compared to using a standard dosimetry protocol. Using the calibration factors determined in the pcsr fields, the ionization chambers and electron diode agree to within 1% with Alanine dosimetry for two clinical VMAT plans. Good agreements between calculations and measurements are found for these two plans when the new formalism is used.

  12. The Role of Non-Formal Education in Combating the HIV Epidemic in the Philippines and Taiwan

    ERIC Educational Resources Information Center

    Morisky, Donald E.; Lyu, Shu-Yu; Urada, Lianne A.

    2009-01-01

    The Philippines is experiencing a low but slowly growing prevalence of HIV, with a UN estimate of 6,000-11,000 cases out of a population of 91 million, and a 150% increase in new cases in 2008 compared to previous years. Earlier education programmes employed non-formal educational training techniques in the southern Philippines to target high-risk…

  13. Multisymplectic Lagrangian and Hamiltonian Formalisms of Classical Field Theories

    NASA Astrophysics Data System (ADS)

    Román-Roy, Narciso

    2009-11-01

    This review paper is devoted to presenting the standard multisymplectic formulation for describing geometrically classical field theories, both the regular and singular cases. First, the main features of the Lagrangian formalism are revisited and, second, the Hamiltonian formalism is constructed using Hamiltonian sections. In both cases, the variational principles leading to the Euler-Lagrange and the Hamilton-De Donder-Weyl equations, respectively, are stated, and these field equations are given in different but equivalent geometrical ways in each formalism. Finally, both are unified in a new formulation (which has been developed in the last years), following the original ideas of Rusk and Skinner for mechanical systems.

  14. A Novel Concept Acquisition Approach Based on Formal Contexts

    PubMed Central

    Qian, Ting; Wei, Ling

    2014-01-01

    As an important tool for data analysis and knowledge processing, formal concept analysis (FCA) has been applied to many fields. In this paper, we introduce a new method to find all formal concepts based on formal contexts. The amount of intents calculation is reduced by the method. And the corresponding algorithm of our approach is proposed. The main theorems and the corresponding algorithm are examined by examples, respectively. At last, several real-life databases are analyzed to demonstrate the application of the proposed approach. Experimental results show that the proposed approach is simple and effective. PMID:25147834

  15. Leveraging Formal Methods and Fuzzing to Verify Security and Reliability Properties of Large-Scale High-Consequence Systems.

    SciTech Connect

    Ruthruff, Joseph.; Armstrong, Robert C.; Davis, Benjamin Garry; Mayo, Jackson R.; Punnoose, Ratish J.

    2012-09-01

    Formal methods describe a class of system analysis techniques that seek to prove specific propertiesabout analyzed designs, or locate flaws compromising those properties. As an analysis capability,these techniques are the subject of increased interest fromboth internal and external customersof Sandia National Laboratories. Given this lab's other areas of expertise, Sandia is uniquelypositioned to advance the state-of-the-art with respect toseveral research and application areaswithin formal methods. This research project was a one-yeareffort funded by Sandia's CyberSecurity S&T Investment Area in its Laboratory Directed Research & Development program toinvestigate the opportunities for formal methods to impactSandia's present mission areas, morefully understand the needs of the research community in the area of formal methods and whereSandia can contribute, and clarify from those potential research paths those that would best advancethe mission-area interests of Sandia. The accomplishmentsfrom this project reinforce the utilityof formal methods in Sandia, particularly in areas relevantto Cyber Security, and set the stagefor continued Sandia investments to ensure this capabilityis utilized and advanced within thislaboratory to serve the national interest.4

  16. Auteur Description: From the Director's Creative Vision to Audio Description

    ERIC Educational Resources Information Center

    Szarkowska, Agnieszka

    2013-01-01

    In this report, the author follows the suggestion that a film director's creative vision should be incorporated into Audio description (AD), a major technique for making films, theater performances, operas, and other events accessible to people who are blind or have low vision. The author presents a new type of AD for auteur and artistic…

  17. The Case for Descriptive Writing.

    ERIC Educational Resources Information Center

    Hauck, Marian K.

    An approach to teaching descriptive writing and its values are discussed. Benefits derived from a descriptive writing unit are said to be the following: (1) Descriptive writing is fun; (2) It enables the instructor to demonstrate that the first word that pops into the writer's mind is often not the best one; (3) There is no easier way in which to…

  18. Three Approaches to Descriptive Research.

    ERIC Educational Resources Information Center

    Svensson, Lennart

    This report compares three approaches to descriptive research, focusing on the kinds of descriptions developed and on the methods used to develop the descriptions. The main emphasis in all three approaches is on verbal data. In these approaches the importance of interpretation and its intuitive nature are emphasized. The three approaches, however,…

  19. Symmetric Space σ-MODEL Dynamics:. Current Formalism

    NASA Astrophysics Data System (ADS)

    Yilmaz, Nejat T.

    After explicitly constructing the symmetric space sigma model Lagrangian in terms of the coset scalars of the solvable Lie algebra gauge in the current formalism, we derive the field equations of the theory.

  20. Scalar heat kernel with boundary in the worldline formalism

    NASA Astrophysics Data System (ADS)

    Bastianelli, Fiorenzo; Corradini, Olindo; Pisani, Pablo A. G.; Schubert, Christian

    2008-10-01

    The worldline formalism has in recent years emerged as a powerful tool for the computation of effective actions and heat kernels. However, implementing nontrivial boundary conditions in this formalism has turned out to be a difficult problem. Recently, such a generalization was developed for the case of a scalar field on the half-space Bbb R+ × Bbb RD-1, based on an extension of the associated worldline path integral to the full Bbb RD using image charges. We present here an improved version of this formalism which allows us to write down non-recursive master formulas for the n-point contribution to the heat kernel trace of a scalar field on the half-space with Dirichlet or Neumann boundary conditions. These master formulas are suitable to computerization. We demonstrate the efficiency of the formalism by a calculation of two new heat-kernel coefficients for the half-space, a4 and a9/2.

  1. Uncovering the triple omeron vertex from Wilson line formalism

    SciTech Connect

    Chirilli, G. A.; Szymanowski, L.; Wallon, S.

    2011-01-01

    We compute the triple omeron vertex from the Wilson line formalism, including both planar and nonplanar contributions, and get perfect agreement with the result obtained in the Extended Generalized Logarithmic Approximation based on Reggeon calculus.

  2. Formal Organizational Structure and Participation in Planning Continuing Professional Education.

    ERIC Educational Resources Information Center

    Fox, Robert D.

    1981-01-01

    This study explored and described the relationship between formal organizational structures and the extent of participation of clients, faculty, and program administrators in planning continuing professional education programs in six Southern land-grant universities. (Author/CT)

  3. Formal methods and digital systems validation for airborne systems

    NASA Technical Reports Server (NTRS)

    Rushby, John

    1993-01-01

    This report has been prepared to supplement a forthcoming chapter on formal methods in the FAA Digital Systems Validation Handbook. Its purpose is as follows: to outline the technical basis for formal methods in computer science; to explain the use of formal methods in the specification and verification of software and hardware requirements, designs, and implementations; to identify the benefits, weaknesses, and difficulties in applying these methods to digital systems used on board aircraft; and to suggest factors for consideration when formal methods are offered in support of certification. These latter factors assume the context for software development and assurance described in RTCA document DO-178B, 'Software Considerations in Airborne Systems and Equipment Certification,' Dec. 1992.

  4. A logarithmic correction in the entropy functional formalism

    NASA Astrophysics Data System (ADS)

    Hammad, Fayçal; Faizal, Mir

    2016-04-01

    The entropy functional formalism allows one to recover general relativity, modified gravity theories, as well as the Bekenstein-Hawking entropy formula. In most approaches to quantum gravity, the Bekenstein-Hawking’s entropy formula acquires a logarithmic correction term. As such terms occur almost universally in most approaches to quantum gravity, we analyze the effect of such terms on the entropy functional formalism. We demonstrate that the leading correction to the micro-canonical entropy in the entropy functional formalism can be used to recover modified theories of gravity already obtained with an uncorrected micro-canonical entropy. Furthermore, since the entropy functional formalism reproduces modified gravity, the rise of gravity-dependent logarithmic corrections turns out to be one way to impose constraints on these theories of modified gravity. The constraints found here for the simple case of an ℱ(R)-gravity are the same as those obtained in the literature from cosmological considerations.

  5. Dominant partition method. [based on a wave function formalism

    NASA Technical Reports Server (NTRS)

    Dixon, R. M.; Redish, E. F.

    1979-01-01

    By use of the L'Huillier, Redish, and Tandy (LRT) wave function formalism, a partially connected method, the dominant partition method (DPM) is developed for obtaining few body reductions of the many body problem in the LRT and Bencze, Redish, and Sloan (BRS) formalisms. The DPM maps the many body problem to a fewer body one by using the criterion that the truncated formalism must be such that consistency with the full Schroedinger equation is preserved. The DPM is based on a class of new forms for the irreducible cluster potential, which is introduced in the LRT formalism. Connectivity is maintained with respect to all partitions containing a given partition, which is referred to as the dominant partition. Degrees of freedom corresponding to the breakup of one or more of the clusters of the dominant partition are treated in a disconnected manner. This approach for simplifying the complicated BRS equations is appropriate for physical problems where a few body reaction mechanism prevails.

  6. Experiences Using Lightweight Formal Methods for Requirements Modeling

    NASA Technical Reports Server (NTRS)

    Easterbrook, Steve; Lutz, Robyn; Covington, Rick; Kelly, John; Ampo, Yoko; Hamilton, David

    1997-01-01

    This paper describes three case studies in the lightweight application of formal methods to requirements modeling for spacecraft fault protection systems. The case studies differ from previously reported applications of formal methods in that formal methods were applied very early in the requirements engineering process, to validate the evolving requirements. The results were fed back into the projects, to improve the informal specifications. For each case study, we describe what methods were applied, how they were applied, how much effort was involved, and what the findings were. In all three cases, formal methods enhanced the existing verification and validation processes, by testing key properties of the evolving requirements, and helping to identify weaknesses. We conclude that the benefits gained from early modeling of unstable requirements more than outweigh the effort needed to maintain multiple representations.

  7. Understanding visualization: a formal approach using category theory and semiotics.

    PubMed

    Vickers, Paul; Faith, Joe; Rossiter, Nick

    2013-06-01

    This paper combines the vocabulary of semiotics and category theory to provide a formal analysis of visualization. It shows how familiar processes of visualization fit the semiotic frameworks of both Saussure and Peirce, and extends these structures using the tools of category theory to provide a general framework for understanding visualization in practice, including: Relationships between systems, data collected from those systems, renderings of those data in the form of representations, the reading of those representations to create visualizations, and the use of those visualizations to create knowledge and understanding of the system under inspection. The resulting framework is validated by demonstrating how familiar information visualization concepts (such as literalness, sensitivity, redundancy, ambiguity, generalizability, and chart junk) arise naturally from it and can be defined formally and precisely. This paper generalizes previous work on the formal characterization of visualization by, inter alia, Ziemkiewicz and Kosara and allows us to formally distinguish properties of the visualization process that previous work does not.

  8. Using formal specification in the Guidance and Control Software (GCS) experiment. Formal design and verification technology for life critical systems

    NASA Technical Reports Server (NTRS)

    Weber, Doug; Jamsek, Damir

    1994-01-01

    The goal of this task was to investigate how formal methods could be incorporated into a software engineering process for flight-control systems under DO-178B and to demonstrate that process by developing a formal specification for NASA's Guidance and Controls Software (GCS) Experiment. GCS is software to control the descent of a spacecraft onto a planet's surface. The GCS example is simplified from a real example spacecraft, but exhibits the characteristics of realistic spacecraft control software. The formal specification is written in Larch.

  9. Hardware description languages for systolic architectures

    SciTech Connect

    Lewis, P.S.

    1984-10-01

    Systolic principles can be used to construct special purpose computer systems that achieve high throughput by exploiting algorithmic properties. These principles of regularity, localized communications, and parallel/pipelined execution nicely match the capabilities of integrated circuit technology. Hence, systolic arrays are an attractive method for building high-speed special-purpose hardware to rapidly solve sophisticated problems. However, the use of special-purpose hardware limits the applications base, making fixed costs such as those associated with system design much more critical. Although design costs are in part reduced by the very nature of systolic systems, further reduction can result from the use of automated design and descriptive tools. The design process stretches from the conception of the algorithm and its mapping onto an architecture down to the electronic implementation. In general, a good set of design tools allows the designer to describe, test, and trade off only those factors that are important at that particular point in the design process. A principle requirement in automating the design process is a formal notational mechanism that is capable of providing complete and unambiguous descriptions of the concepts being explored. This notational mechanism then provides a common basis for comparisons between alternate methods and an input mechanism to automated design tools. This thesis identifies the notational features that are necessary for the description of highly parallel, regular architectures such as systolic arrays. A set of language criteria is developed. A number of the more popular HDLs are evaluated using these criteria and their shortcomings noted. 65 references.

  10. Formally specifying the logic of an automatic guidance controller

    NASA Technical Reports Server (NTRS)

    Guaspari, David

    1990-01-01

    The following topics are covered in viewgraph form: (1) the Penelope Project; (2) the logic of an experimental automatic guidance control system for a 737; (3) Larch/Ada specification; (4) some failures of informal description; (5) description of mode changes caused by switches; (6) intuitive description of window status (chosen vs. current); (7) design of the code; (8) and specifying the code.

  11. Skinner-Rusk unified formalism for higher-order systems

    NASA Astrophysics Data System (ADS)

    Prieto-Martínez, Pedro Daniel; Román-Roy, Narciso

    2012-07-01

    The Lagrangian-Hamiltonian unified formalism of R. Skinner and R. Rusk was originally stated for autonomous dynamical systems in classical mechanics. It has been generalized for non-autonomous first-order mechanical systems, first-order and higher-order field theories, and higher-order autonomous systems. In this work we present a generalization of this formalism for higher-order non-autonomous mechanical systems.

  12. Formal functional test designs with a test representation language

    NASA Technical Reports Server (NTRS)

    Hops, J. M.

    1993-01-01

    The application of the category-partition method to the test design phase of hardware, software, or system test development is discussed. The method provides a formal framework for reducing the total number of possible test cases to a minimum logical subset for effective testing. An automatic tool and a formal language were developed to implement the method and produce the specification of test cases.

  13. Formalizing the definition of meta-analysis in Molecular Ecology.

    PubMed

    ArchMiller, Althea A; Bauer, Eric F; Koch, Rebecca E; Wijayawardena, Bhagya K; Anil, Ammu; Kottwitz, Jack J; Munsterman, Amelia S; Wilson, Alan E

    2015-08-01

    Meta-analysis, the statistical synthesis of pertinent literature to develop evidence-based conclusions, is relatively new to the field of molecular ecology, with the first meta-analysis published in the journal Molecular Ecology in 2003 (Slate & Phua 2003). The goal of this article is to formalize the definition of meta-analysis for the authors, editors, reviewers and readers of Molecular Ecology by completing a review of the meta-analyses previously published in this journal. We also provide a brief overview of the many components required for meta-analysis with a more specific discussion of the issues related to the field of molecular ecology, including the use and statistical considerations of Wright's FST and its related analogues as effect sizes in meta-analysis. We performed a literature review to identify articles published as 'meta-analyses' in Molecular Ecology, which were then evaluated by at least two reviewers. We specifically targeted Molecular Ecology publications because as a flagship journal in this field, meta-analyses published in Molecular Ecology have the potential to set the standard for meta-analyses in other journals. We found that while many of these reviewed articles were strong meta-analyses, others failed to follow standard meta-analytical techniques. One of these unsatisfactory meta-analyses was in fact a secondary analysis. Other studies attempted meta-analyses but lacked the fundamental statistics that are considered necessary for an effective and powerful meta-analysis. By drawing attention to the inconsistency of studies labelled as meta-analyses, we emphasize the importance of understanding the components of traditional meta-analyses to fully embrace the strengths of quantitative data synthesis in the field of molecular ecology.

  14. Techniques for Forecasting Air Passenger Traffic

    NASA Technical Reports Server (NTRS)

    Taneja, N.

    1972-01-01

    The basic techniques of forecasting the air passenger traffic are outlined. These techniques can be broadly classified into four categories: judgmental, time-series analysis, market analysis and analytical. The differences between these methods exist, in part, due to the degree of formalization of the forecasting procedure. Emphasis is placed on describing the analytical method.

  15. Adolescent thinking ála Piaget: The formal stage.

    PubMed

    Dulit, E

    1972-12-01

    Two of the formal-stage experiments of Piaget and Inhelder, selected largely for their closeness to the concepts defining the stage, were replicated with groups of average and gifted adolescents. This report describes the relevant Piagetian concepts (formal stage, concrete stage) in context, gives the methods and findings of this study, and concludes with a section discussing implications and making some reformulations which generally support but significantly qualify some of the central themes of the Piaget-Inhelder work. Fully developed formal-stage thinking emerges as far from commonplace among normal or average adolescents (by marked contrast with the impression created by the Piaget-Inhelder text, which chooses to report no middle or older adolescents who function at less than fully formal levels). In this respect, the formal stage differs appreciably from the earlier Piagetian stages, and early adolescence emerges as the age for which a "single path" model of cognitive development becomes seriously inadequate and a more complex model becomes essential. Formal-stage thinking seems best conceptualized, like most other aspects of psychological maturity, as a potentiality only partially attained by most and fully attained only by some.

  16. Higher order nonlocal formalism for linear analysis of a magnetized multispecies plasma with inhomogeneous flows

    SciTech Connect

    Gavrishchaka, V.V.; Ganguli, G.I.; Bakshi, P.M.; Koepke, M.E.

    1998-01-01

    The formalism necessary to study the collective properties of a plasma system with inhomogeneous flows is nonlocal and generally in the form of an integrodifferential equation. Usually the eigenvalue condition is reduced to a second-order differential equation for simplicity. While the gross physical behavior of the system can be obtained from the second-order differential equation level of description, higher-order corrections are necessary for greater accuracy. The limit in which the scale-size of the velocity inhomogeneity is large compared to the ion gyroradius is considered and a transverse flow profile sharply localized in space ({open_quotes}top-hat{close_quotes} profile) is assumed. In this limit, a simple analytical method for the solution of the general eigenvalue condition to all orders is developed. A comparison of the properties of the solutions obtained from the second-order differential equation level of description with those obtained from higher orders is presented. Both the resonant (dissipative) and the nonresonant (reactive) effects of velocity shear are considered. It is found that while the overall features are well represented by the second-order level of description, the higher-order corrections moderate the destabilizing effects due to velocity shear, which can be quite significant in some cases. {copyright} {ital 1998 American Institute of Physics.}

  17. Direction and Description

    NASA Astrophysics Data System (ADS)

    Ben-Menahem, Yemima

    This paper deals with the dependence of directionality in the course of events-or our claims concerning such directionality-on the modes of description we use in speaking of the events in question. I argue that criteria of similarity and individuation play a crucial role in assessments of directionality. This is an extension of Davidson's claim regarding the difference between causal and explanatory contexts. The argument is based on a characterisation of notions of necessity and contingency that differ from their modal logic counterparts on the one hand, and from causality and chance on the other. I show that some types of directionality are perfectly compatible with both determinism and indeterminism at the microscopic level, and that there is no likelihood of, or advantage to, reducing such directionality to other laws or causal processes.

  18. Symmetrical gait descriptions

    NASA Astrophysics Data System (ADS)

    Dunajewski, Adam; Dusza, Jacek J.; Rosado Muñoz, Alfredo

    2014-11-01

    The article presents a proposal for the description of human gait as a periodic and symmetric process. Firstly, the data for researches was obtained in the Laboratory of Group SATI in the School of Engineering of University of Valencia. Then, the periodical model - Mean Double Step (MDS) was made. Finally, on the basis of MDS, the symmetrical models - Left Mean Double Step and Right Mean Double Step (LMDS and RMDS) could be created. The method of various functional extensions was used. Symmetrical gait models can be used to calculate the coefficients of asymmetry at any time or phase of the gait. In this way it is possible to create asymmetry, function which better describes human gait dysfunction. The paper also describes an algorithm for calculating symmetric models, and shows exemplary results based on the experimental data.

  19. Task Description Language

    NASA Technical Reports Server (NTRS)

    Simmons, Reid; Apfelbaum, David

    2005-01-01

    Task Description Language (TDL) is an extension of the C++ programming language that enables programmers to quickly and easily write complex, concurrent computer programs for controlling real-time autonomous systems, including robots and spacecraft. TDL is based on earlier work (circa 1984 through 1989) on the Task Control Architecture (TCA). TDL provides syntactic support for hierarchical task-level control functions, including task decomposition, synchronization, execution monitoring, and exception handling. A Java-language-based compiler transforms TDL programs into pure C++ code that includes calls to a platform-independent task-control-management (TCM) library. TDL has been used to control and coordinate multiple heterogeneous robots in projects sponsored by NASA and the Defense Advanced Research Projects Agency (DARPA). It has also been used in Brazil to control an autonomous airship and in Canada to control a robotic manipulator.

  20. Description of Jet Breakup

    NASA Technical Reports Server (NTRS)

    Papageorgiou, Demetrios T.

    1996-01-01

    In this article we review recent results on the breakup of cylindrical jets of a Newtonian fluid. Capillary forces provide the main driving mechanism and our interest is in the description of the flow as the jet pinches to form drops. The approach is to describe such topological singularities by constructing local (in time and space) similarity solutions from the governing equations. This is described for breakup according to the Euler, Stokes or Navier-Stokes equations. It is found that slender jet theories can be applied when viscosity is present, but for inviscid jets the local shape of the jet at breakup is most likely of a non-slender geometry. Systems of one-dimensional models of the governing equations are solved numerically in order to illustrate these differences.